Article

A new technique for cement augmentation of the sliding hip screw in proximal femur fractures

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Abstract

Fractures of the osteoporotic proximal femur are a significant source of mortality and morbidity in today's ageing population. Even with modern fixation techniques such as the sliding hip screw, a certain percentage of fixations will fail due to cut-out of the screw. This study presents a new method for augmenting hip screws with cement to reinforce the fixation. Unstable pertrochanteric fractures were created in paired osteoporotic cadaver femora (n=10). The fractures were fixed using either standard fixation techniques (dynamic hip screw), or using a dynamic hip screw augmented with cement. Cement was introduced using a customised jig to guide cement into a region superior to the screw in the femoral head. Cut-out resistance was assessed using a biaxial material testing machine, with loading applied in compression until failure. The new cement augmentation technique significantly improved the cut-out strength of the fixation (mean 42%; P=0.032). The failure mechanism for both groups was the same, with failure occurring through compression of the cancellous bone superior to the screw. The mean increase in temperature at the femoral neck was 3.7 degrees C in augmented bones, which is much lower than values previously reported for polymethylmethacrylate cements. Several benefits with this technique have emerged. The method is technically straightforward. The risk of cement penetration into the joint is reduced, and cement is targetted to the areas of the femoral head where it is most needed. The exothermic reaction is minimised by reducing the volume of cement used. The first clinical results are promising.

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... We employed a biomechanical testing model similar to prior studies (Olsen et al., 2011; Zdero et al., 2008). In order to simulate the anatomic alignment and joint reactive force vector of the femur, the specimen was oriented such that it was in 20° of lateral tilt in the coronal plane (Stoffel et al., 2008 ). The specimen was aligned to neutral in the sagittal and axial planes. ...
... The test frame actuator was equipped with a 22 kN load cell and custommade load application device consisting of a titanium acetabular cup with a lipped ultra-high molecular weight polyethylene (UHMWPE) liner (Stryker, Kalamazoo, MI, USA) (Fig. 2) of diameter slightly larger than the femoral head. Each specimen was loaded with a continuous axial compressive load at a rate of 2 mm/s (Olsen et al., 2011; Schileo et al., 2008; Stoffel et al., 2008) until catastrophic failure of the femur occurred. This displacement rate is more consistent with those of daily living, as opposed to those experienced during a sideways fall, which have been estimated at 100 mm/s (de Bakker et al., 2009). ...
... Secondly, our biomechanical testing methodology consisted only of quasi-static axial load application, and does not account for the multi-planar or dynamic loading likely experienced in vivo. However, based on prior literature we believe that loading the femur in 20° of lateral tilt in the coronal plane represents an accurate summation of the main forces acting at the hip during the one-legged stance phase of gait (Bergmann et al., 2001; Stoffel et al., 2008; Wheeler et al., 1997). Cyclic loading of the femoral pairs may also be more physiologically relevant . ...
... Of 411 studies subjected to critical analysis, 22 met the inclusion criteria. They were divided into in vitro [52][53][54][55][56][57][58][59][60][61][62][63] and in vivo studies (Tables I and II). [48][49][50][51][64][65][66][67][68][69] In vitro (experimental) studies. ...
... In vitro studies almost always concentrated on the use of bone cement for augmentation of fixation of the implant or bone stock. [53][54][55][56][58][59][60][61][62][63] Two different cements were examined, namely, polymethylmethacrylate (PMMA) cement 56,58,59,[61][62][63] and calciumphosphate degradable cement. 55,56,60,62 Only one study used a composite. ...
... In vitro studies almost always concentrated on the use of bone cement for augmentation of fixation of the implant or bone stock. [53][54][55][56][58][59][60][61][62][63] Two different cements were examined, namely, polymethylmethacrylate (PMMA) cement 56,58,59,[61][62][63] and calciumphosphate degradable cement. 55,56,60,62 Only one study used a composite. ...
Article
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Failure of fixation is a common problem in the treatment of osteoporotic fractures around the hip. The reinforcement of bone stock or of fixation of the implant may be a solution. Our study assesses the existing evidence for the use of bone substitutes in the management of these fractures in osteoporotic patients. Relevant publications were retrieved through Medline research and further scrutinised. Of 411 studies identified, 22 met the inclusion criteria, comprising 12 experimental and ten clinical reports. The clinical studies were evaluated with regard to their level of evidence. Only four were prospective and randomised. Polymethylmethacrylate and calcium-phosphate cements increased the primary stability of the implant-bone construct in all experimental and clinical studies, although there was considerable variation in the design of the studies. In randomised, controlled studies, augmentation of intracapsular fractures of the neck of the femur with calcium-phosphate cement was associated with poor long-term results. There was a lack of data on the long-term outcome for trochanteric fractures. Because there were only a few, randomised, controlled studies, there is currently poor evidence for the use of bone cement in the treatment of fractures of the hip.
... Osteoporotic fractures are one of the major problems in today's trauma and orthopaedic surgery and will inevitably increase due to the increasing life expectancy. 1 An investigation of Melton et al. showed osteoporotic bone mineral conditions in 58% of women aged 70-79 years and even 84% in women over 80 years. 2 These circumstances lead to an improved fracture management and patient care: angular stable locking for plates with the possibility of polyaxial locking and angular stable locked intramedullary nails 3-6 as well as augmentations techniques 7,8 were introduced. ...
... Augmentation procedures have shown the potential to increase primary stability and failure resistance. 7,8,12,13 This may result in decreased complications rates (secondary dislocation, cut-out, revision surgery) and earlier patient mobilisation with weight bearing. Thus, secondary complications may be reduced as well. ...
... 7 Stoffel et al. investigated cement augmentation of the dynamic hip screw and found significant improvement of the cut-out strength in the augmented specimen. 8 Sermon et al. determined the potential of augmentation in the treatment of proximal femoral fractures using the proximal femoral nail antirotational (PFNA) with the helical blade. In an artificial bone model they found a significant increased number of cycles to failure in the augmented group. ...
Article
PurposeOsteoporotic fractures of the distal femur are an underestimated and increasing problem in trauma and orthopaedic surgery. Therefore, this study investigates the biomechanical potential of implant augmentation in the treatment of these fractures.Methods Twelve osteoporotic surrogate distal femora were randomly assigned to the augmented or non-augmented group. All specimens were fixed using the LCP DF. In the augmented group additionally 1 ml Vertecem V+ was injected in each screw hole before screw positioning. The construct represents an AO 33 A3 fracture. Biomechanical testing was performed as sinusoidal axial loading between 50 and 500 N with 2 Hz for 45,000 cycles, followed by loading between 50 and 750 N until failure.ResultsThe augmented group showed significant higher axial stiffness (36%). Additionally the displacement after 45,000 cycles was 3.4 times lower for the augmented group (0.68 ± 0.2 mm vs. 2.28 ± 0.2 mm). Failure occurred after 45,130 cycles (SD 99) in all of the non-augmented specimens and in two specimens of the augmented group after 69,675 cycles (SD 1729). Four of the augmented specimens showed no failure. The failure mode of all specimens in both groups was a medial cut-out.Conclusions This study shows a promising potential of implant augmentation in the treatment of osteoporotic distal femur fractures.
... (3) Several methods, such as the Medoff sliding plate, intramedullary nailing, primary endoprosthesis, and bone augmentation using polymethylmethacrylate (PMMA) cement or calcium phosphate cement, have been proposed for unstable ITFs. (4)(5)(6)(7)(8) Since 1975, PMMA cement-augmented DHS have been used as a solution in unstable ITFs by adding an anchoring ability to the lag screw. (9) Some encouraging results have been observed, showing a higher success rate and better functional recovery than with conventional DHS. ...
... (10,11) However, complications such as osteonecrosis of the femoral head, nonunion, infection, and screw cut-out can still occur when using PMMA cement augmentation. (7,12) Therefore, our aim was to investigate the complications and failure modes in PMMA cement-augmented DHS. This retrospective study was approved by the institutional review board of our hospital (No 99-1002B). ...
... Stoffel et al. found the mean increase in temperature at the femoral neck was 3.7°C in augmented bones, using a modified method. (7) Boner et al. found the highest temperatures were measured inside the PMMA, with a significant drop in average maximum temperatures from the center of the PMMA to the PMMA/bone interface. (32) There is a risk of thermal necrosis with PMMA layer thicknesses greater than 5.0 mm. ...
Article
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Polymethylmethacrylate (PMMA) cement-augmented dynamic hip screws (DHS) have been used as a solution in unstable intertrochanteric fractures (ITF). Our aim was to investigate the complications in PMMA cement-augmented DHS. All patients who had received DHS plate osteosynthesis with or without PMMA cement augmentation from August 2005 to July 2009 in one medical center were retrospectively reviewed. The fractures were classified as unstable (31-A2.2, 31-A2.3 and 31-A3) on the basis of the Arbeitsgemeinschaft für Osteosynthesefragen classification. Inclusion criteria were patients older than 75 years, unstable ITF treated with cement-augmented DHS, and a minimum of 12 months of follow-up. Exclusion criteria were stable ITFs, incomplete chart records and imaging studies, loss to follow-up or death before bone union. Three hundred twenty-one patients received DHS during the study period. Sixty-seven patients were included in the study (25 men and 42 women; mean age, 81.2 years). The mean follow-up time was 40.2 months, and the mean union time was 18.5 weeks (12-40 weeks). No patient had a lag screw cut-out. Six patients had delayed union or nonunion with side plate failures, including side plate breakage in 1 patient, screw breakage in 3, screw pullout in 1, and recurrent side plate breakage and screw breakage in 1. Deep infection occurred in 1 patient, and 1 had osteonecrosis at the femoral head. The procedure-related complication rate was 8.9%. Cement-augmented DHS have a different failure mode than screw cutout in conventional DHS. Failures tended to be more related to delayed union, nonunion and resultant side plate construct failure.
... In a systematic review on trochanteric fractures [15] and in a multicentre randomized controlled trial [16], no clear improvements in functional outcomes were detected. Several biomechanical studies show some advantages of cement applications in proximal femur fracture fixations [17][18][19][20][21][22], especially in cases of eccentric implant positioning [17] or low bone mineral density [18]. As a rule, the benefit of additional augmentation techniques depends on both the fracture morphology and the stability of the implant system itself and hence on the stability of the bone/implant construct [23]. ...
... In the past, many biomechanical investigations suggested a clear benefit from applying cement to the bone/screw interface [16][17][18]20,21]. Von der Linden et al. reported a better survival of augmented sliding hip screw constructs during cyclic testing, enhancing the implant anchorage [22]. ...
... Von der Linden et al. reported a better survival of augmented sliding hip screw constructs during cyclic testing, enhancing the implant anchorage [22]. Stoffel et al. showed advantages such as an increase of 42% in cut-out resistance in cement-augmented dynamic hip screws [21]. PMMA-augmented helical blades increased the cut-out resistance in human cadaveric femoral heads [18]. ...
... Of these, 39 studies met the study criteria. 23 studies were clinical, while 16 were biomechanical [42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57]. (Table 1) 29 studies were deemed high quality, 10 moderate quality, and 0 low quality. ...
... Evaluation of PMMA augmentation of sliding hip screws for IT fractures in osteoporotic cadaveric proximal femurs showed decreased fracture displacement relative to uncemented controls [54]. Likewise, a study of PMMA-augmented sliding hip screw fixation of osteoporotic cadaveric femurs with IT fractures demonstrated increased cut-out strength and load to failure in the cemented group [52]. PFNA implants augmented with PMMA also increased the number of loading cycles to failure in both low-density polyurethane foam [57] and osteopenic cadaveric proximal femur models [42]. ...
Article
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Introduction Achieving durable mechanical stability in geriatric intertrochanteric proximal femur fractures remains a challenge. Concomitant poor bone quality, unstable fracture patterns, and suboptimal reduction are additional risk factors for early mechanical failure. Cement augmentation of the proximal locking screw or blade is one proposed method to augment implant anchorage. The purpose of this review is to describe the biomechanical and clinical evidence for cement augmentation of geriatric intertrochanteric fractures, and to elaborate indications for cement augmentation. Methods The PubMed database was searched for English language studies up to January 2021. Studies that assessed effect of calcium phosphate or methylmethacrylate cement augmentation during open reduction and internal fixation of intertrochanteric fractures were included. Studies with sample size < 5, nontraumatic or periprosthetic fractures, and nonunion or revision surgery were excluded. Study selection adhered to PRISMA criteria. Results 801 studies were identified, of which 40 met study criteria. 9 studies assessed effect of cement augmentation on fracture displacement. All but one found that cement decreased fracture displacement. 10 studies assessed effect of cement augmentation on total load or cycles to failure. All but one demonstrated that augmented implants increased this variable. Complication rates of cement augmentation during ORIF of intertrochanteric fractures ranged from 0 to 47%, while non-augmented implants ranged from 0 to 51%. Reoperation rates ranged from 0 to 11% in the cement-augmented group and 0 to 11% in the non-augmented group. Fixation failure ranged from 0 to 11% in the cement-augmented group and 0 to 20% in the non-augmented group. Nonunion ranged from 0 to 3.6% in the cement-augmented group and 0 to 34% in the non-augmented group. Conclusions Calcium phosphate or PMMA-augmented CMN fixation of IT fractures increased construct stability and improved outcomes in biomechanical and early clinical studies. The findings of these studies suggest an important role for cement augmentation in patient populations at high risk of mechanical failure.
... In order to improve the mechanical anchorage of the screw and prevent re-operations, various attempts have been made to reinforce the fragile bone with polymer based injectable materials. Cadaver studies and small sized clinical studies have indicated a preventive effect of poly methyl methacrylate (PMMA) based augmentation on screw or blade cut-out but evidence from larger randomized controlled trials is lacking (Stoffel et al., 2008;Gupta et al., 2012). Drawbacks include the exothermic setting reaction of PMMA, which can lead to necrosis of the femoral head, and the inability of the material to remodel into living bone. ...
... Others have injected isothermally setting CaP cement into the entire reamed lag-screw canal, and in another smaller canal parallel to the reamed lag-screw canal (Mattsson and Larsson, 2006). Injections through fenestrated lag-screws have also been tested (Mattsson and Larsson, 2004;Stoffel et al., 2008;Fuchs et al., 2019). Although the concept of using biodegradable materials is compelling, several limitations need to be addressed for standardizing the surgical technique; 1) exactly controlling the volume and spreading of the delivered material, 2) the time constraint wherein the surgeon needs to fully insert the lag-screw before the material sets and, 3) using a delivery technique avoiding leakage into the venous system around the femoral head and neck. ...
Article
Full-text available
Pertrochanteric fractures (TF) due to osteoporosis constitute nearly half of all proximal femur fractures. TFs are treated with a surgical approach and fracture fixation is achieved using metallic fixation devices. Poor quality cancellous bone in osteoporotic patients makes anchorage of a fixation device challenging, which can lead to failure of the fracture fixation. Methods to reinforce the bone-implant interface using bone cement (PMMA) and other calcium phosphate cements in TFs have been described earlier but a clear evidence on the advantage of using such biomaterials for augmentation is weak. Furthermore, there is no standardized technique for delivering these biomaterials at the bone-implant interface. In this study, we firstly describe a method to deliver a calcium sulphate/hydroxyapatite (CaS/HA) based biomaterial for the augmentation of a lag-screw commonly used for TF fixation. We then used an osteoporotic Sawbones model to study the consequence of CaS/HA augmentation on the immediate mechanical anchorage of the lag-screw to osteoporotic bone. Finally, as a proof-of-concept, the method of delivering the CaS/HA biomaterial at the bone-implant interface as well as spreading of the CaS/HA material at this interface was tested in patients undergoing treatment for TF as well as in donated femoral heads. The mechanical testing results indicated that the CaS/HA based biomaterial increased the peak extraction force of the lag-screw by 4 times compared with un-augmented lag-screws and the results were at par with PMMA. The X-ray images from the patient series showed that it was possible to inject the CaS/HA material at the bone-implant interface without applying additional pressure and the CaS/HA material spreading was observed at the interface of the lag-screw threads and the bone. Finally, the spreading of the CaS/HA material was also verified on donated femoral heads and micro-CT imaging indicated that the entire length of the lag-screw threads was covered with the CaS/HA biomaterial. In conclusion, we present a novel method for augmenting a lag-screw in TFs, which could potentially reduce the risk of fracture fixation failure and reoperation in fragile osteoporotic patients.
... Cement augmentation of hip fracture implants has been examined in human cadaveric studies to improve implant stability [9,10]. Cement is injected into the femoral head of osteoporotic bone to enhance the implant-bone interface. ...
... Eriksson et al. showed that PMMA-augmented screws achieved significantly higher resistance to torque and pull-out from synthetic bone than their calcium phosphate cement-augmented and non-augmented counterparts [25]. Several other in vitro studies involving PMMA-augmented implants in human cadaveric models also produced higher failure loads and reduced cut-out events for conventional hip screws and sliding hip screws [10,26]. The application of cement augmentation to blade fixation in the cephalomedullary device has been a focus of more recent studies. ...
Article
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IntroductionCephallomedullary nail fixation is currently the most popular treatment for pertrochanteric fractures. Despite continuous improvement in implant design, fixation failures still occur in a concerning number of cases. This study aims to evaluate the effect of cement augmentation of the new-generation Trochanteric Femoral Nail Advanced (TFNA) perforated spiral blade on complications including fixation failure in the elderly population.Materials and methodsWe retrospectively evaluated 107 patients aged 65 + treated for pertrochanteric fractures via TFNA between 2015 and 2019 based on whether cementation was used. Baseline demographics, fracture classifications, and reduction quality were compared. Patients with a follow-up of at least 6 months were analyzed for the primary outcome of fixation failure. All patients, regardless of loss to follow-up within 6 months, were analyzed for other complications including mortality.ResultsSeventy-six patients (47 cemented, 29 non-cemented) had a minimum follow-up of 6 months (mean 13 months). There were no statistically significant differences between the two treatment groups in terms of patient demographics, ASA or AO/OTA fracture classification, reduction quality, or length of follow-up. There was a lower rate of fixation failure in the cement-augmented (CA) group versus the non-cement-augmented (NCA) group (2.1% vs 13.8%; p = 0.047). No cut-out or cut-through was observed in the CA group. Seven patients had adverse intraoperative events, with a significantly higher rate of fixation failure in these patients (40% vs 2.8%; p = 0.00). There were no statistically significant differences in 30-day mortality (6.3% CA vs 4.3% NCA; p = 0.632) or 3-month mortality (9.5% CA vs 12.8% NCA; p = 0.589).Conclusions Cementation of TFNA blades may decrease risk of fixation failure, however, the surgeon must be aware of potential complications such as cement leakage into the hip joint and be able to manage them as they arise.
... Biomechanical studies could demonstrate the benefit of augmentation techniques in osteoporotic fracture fixation. 1,[4][5][6]12 Clinically, augmentation has been introduced for the treatment of osteoporotic proximal femoral fractures. 13 Previously, our group has shown the potential of augmentation in osteoporotic distal femur fractures using an artificial bone model. 2 As a further step, the aim of this biomechanical study was to identify the capability of cement augmentation to improve implant anchorage in osteoporotic distal femur fractures using human specimens and modified cannulated and perforated screws in an unstable fracture model fixed with an anatomical locking plate. ...
... Stoffel et al 12 investigated cement augmentation of dynamic hip screws and found significant improvement of the cutout strength in the augmented group. 12 Sermon et al 6 investigated the potential of augmentation in the treatment of proximal femoral fractures using the proximal femoral nail antirotational with the helical blade. In the artificial bone model, augmentation could significantly increase the number of cycles until failure. ...
Article
The increasing problems in the field of osteoporotic fracture fixation results in specialized implants as well as new operation methods, for example, implant augmentation with bone cement. The aim of this study was to determine the biomechanical impact of augmentation in the treatment of osteoporotic distal femur fractures. Seven pairs of osteoporotic fresh frozen distal femora were randomly assigned to either an augmented or nonaugmented group. In both groups, an Orthopaedic Trauma Association 33 A3 fractures was fixed using the locking compression plate distal femur and cannulated and perforated screws. In the augmented group, additionally, 1 mL of polymethylmethacrylate cement was injected through the screw. Prior to mechanical testing, bone mineral density (BMD) and local bone strength were determined. Mechanical testing was performed by cyclic axial loading (100 N to 750 N + 0.05N/cycle) using a servo-hydraulic testing machine. As a result, the BMD as well as the axial stiffness did not significantly differ between the groups. The number of cycles to failure was significantly higher in the augmented group with the BMD as a significant covariate. In conclusion, cement augmentation can significantly improve implant anchorage in plating of osteoporotic distal femur fractures.
... Several biomechanical studies could show some advantages of cement usage, especially in cases of eccentric implant position or low bone density [62]. In specimens with intertrochanteric fracture using an augmented SHS, an enhanced cut-out resistance by 42% was shown [63]. However, Hofmann-Fliri et al. showed no biomechanical advantage with respect to secondary displacement following augmentation of three cannulated screws in a nondisplaced femoral neck fracture [64]. ...
Article
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There is an enormous humanitarian and socioeconomic need to improve the quality and effectiveness of care for patients with hip fracture. To reduce mechanical complications in the osteosynthesis of proximal femoral fractures, improved fixation techniques have been developed including blade or screw-anchor devices, locked minimally invasive or cement augmentation strategies. However, despite numerous innovations and advances regarding implant design and surgical techniques, systemic and mechanical complication rates remain high. Treatment success depends on secure implant fixation in often-osteoporotic bone as well as on patient-specific factors (fracture stability, bone quality, comorbidity, and gender) and surgeon-related factors (experience, correct reduction, and optimal screw placement in the head/neck fragment). For fracture fixation, the anchorage of the lag screw within the femoral head plays a crucial role depending on the implant’s design. Meta-analyses and randomized controlled studies demonstrate that there is a strong trend towards arthroplasty treating geriatric femoral neck fractures. However, for young adults as well as older patients with less compromised bone quality, or in undisplaced fractures, head-preserving therapy is preferred as it is less invasive and associated with good functional results. This review summarizes the evidence for the internal fixation of femoral neck fractures and trochanteric femoral fractures in elderly patients. In addition, biomechanical considerations regarding implant anchorage in the femoral head including rotation, migration, and femoral neck shortening are made. Finally, cement augmentation strategies for hip fracture implants are evaluated critically.
... A sideopening cannula is used to selectively position cement at the blade tip. The risk of leakage into the fracture site 16,[22][23][24][25][26][27] or at the level of the sliding mechanism of the nail is reduced. Leakage into the hip by perforating the head, frequently created during guide-wire placement, can be excluded by performing a leakage test prior to augmentation. ...
Article
Several studies proved the beneficial effect of cement augmentation of proximal femoral nail antirotation (PFNA) blades on implant purchase in osteoporotic bone. We investigated the effect of different localizations and amounts of bone cement. Polyurethane foam specimens were instrumented with a PFNA blade and subsequently augmented with PMMA bone cement. Eight study groups were formed based on localization and amount of cement volume related to the blade. All specimens underwent cyclic loading with physiological orientation of the force vector until construct failure. Foam groups were compared between each other and to a cadaveric control group. The experiments revealed a significant dependency of implant purchase on localization and amount of cement. Biomechanically favorable cement positions were found at the implant tip and at the cranial side. However, none of the tested augmentation patterns performed significantly inferior to the cadaveric benchmark. These findings will allow surgeons to further reduce the amount of injected PMMA, decreasing the risk of cement leakage or cartilage damage. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.
... The main concerns about such a device were a potential disturbance of bone metabolism [14,19,37] and the induction of cartilage damage although there are several investigations rebutting this [4,41,43]. The current prospective multicenter trial was conducted to evaluate the long-term clinical outcome as well as the radiological results with the standardized augmentation of the PFNA. ...
Article
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Pertrochanteric fractures are increasing and their operative treatment remains under discussion. Failures needing reoperations such as a cut-out are reported to be high and are associated with multiple factors including poor bone quality, poor fracture reduction and improper implant placement. The PFNA(®) with perforated blade offers an option for standardized cement augmentation with a PMMA cement to provide more stability to the fracture fixation. It remains unclear if the augmentation of this implant does any harm in a longer time span. This prospective multicenter study shows clinical and radiological results with this implant with a mean follow-up time of 15 months. In 5 European clinics, 62 patients (79 % female, mean age 85.3 years) suffering from an osteoporotic pertrochanteric fracture (AO 31) were treated with the augmented PFNA(®). The primary objectives were assessment of activities of daily living, pain and mobility. Furthermore, the X-rays were analyzed for the cortical thickness index, changes of the trabecular structure around the cement and the hip joint space. The mean follow-up time was 15.3 months. We observed callus healing in all cases. The surgical complication rate was 3.2 % with no complication related to the cement augmentation. A mean volume of 3.8 ml of cement was injected and no complication was reported due to this procedure. 59.9 % reached their prefracture mobility level until follow-up. The mean hip joint space did not change significantly until follow-up and there were no signs of osteonecrosis in the follow-up X-rays. Furthermore, no blade migration was assessed. This study makes us believe that the standardized augmentation of the PFNA with a perforated blade is a safe method to treat pertrochanteric femoral fractures. It leads to good functional results and is not associated with cartilage or bone necrosis.
... Intra-osseous acrylic cement may improve epiphyseal anchorage. After an experimental validation phase [40,41], acrylic cement was successfully associated to treat unstable trochanteric fracture in severe osteoporosis, using screw-plates or intra-medullary nails [42,43]. ...
Article
Recent trochanteric fracture is frequent in adults, and mainly affects elderly patients who risk loss of independence. Treatment is surgical, of various sorts. Open reduction internal fixation (ORIF) with intra- or extra-medullary implants is the most frequent attitude in these fractures, which usually heal easily. In elderly patients, arthroplasty is an alternative of choice for some authors. These different treatment modalities are presented, focusing on technical details. Possible technical difficulties and the means of dealing with them are considered. Published results help in choosing the treatment most suitable for a particular type of fracture in a particular patient.
... 10 Other biomechanical studies report similar advantages and, hence, draw a consistent picture of the concept. This includes PMMA augmentation of a sliding hip screw, 11,12 of proximal humerus plate screws, 13 of distal femur and proximal tibia plate screws, 14,15 of lag screws 16 and of a tibiotalocalcaneal arthrodesis nail. 17 Thus, there is reason to presume that augmenting the tips of cannulated cancellous screws for fixation of femoral neck fractures might improve implant anchorage in a similar manner. ...
Article
Femoral neck fractures in the elderly are a common problem in orthopedics. Augmentation of screw fixation with bone cement can provide better stability of implants and lower the risk of secondary displacement. This study aimed to investigate whether cement augmentation of three cannulated screws in non-displaced femoral neck fractures could increase implant fixation. A femoral neck fracture was simulated in 6 paired human cadaveric femora and stabilized with three 7.3mm cannulated screws. Pairs were divided into two groups: conventional instrumentation vs. additional cement augmentation of screw tips with 2ml TraumacemV+ each. Biomechanical testing was performed by applying cyclic axial load until failure. Failure cycles, axial head displacement, screw angle changes, telescoping and screw cut-out were evaluated. Failure (15mm actuator displacement) occurred in the augmented group at 12'500 cycles (± 2480) compared to 15'625 cycles (± 4215) in the non-augmented group (p = 0.041). When comparing 3 mm vertical displacement of the head no significant difference (p = 0.72) was detected between the survival curves of the two groups. At 8'500 load-cycles (early onset failure) the augmented group demonstrated a change in screw angle of 2.85° (± 0.84) compared to 1.15° (± 0.93) in the non-augmented group (p = 0.013). The results showed no biomechanical advantage with respect to secondary displacement following augmentation of three cannulated screws in a non-displaced femoral neck fracture. Consequently, the indication for cement augmentation to enhance implant anchorage in osteoporotic bone has to be considered carefully taking into account fracture type, implant selection and biomechanical surrounding. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
... Th e requirement for augmentation of bone during orthopedic surgery is a common scenario. [1][2][3][4][5][6] Internal stabilization of fractured or otherwise mechanically destabilized bone oft en occurs in the presence of compromised bone quality. Placement of hardware into bone of reduced mechanical competency can signifi cantly aff ect the performance of the fi xation hardware, and ultimately the clinical outcome. ...
Article
To determine changes in drill bit performance attributable to application of a triaxially resilient, hard-carbon thin film. In vitro mechanical study. Five matched pairs of control bits and bits with a carbon nanofilm applied were tested in equine cortical bone and a synthetic bone substrate. Thirty sequential holes were drilled with each bit. Drilling time was recorded for all holes. Maximum substrate temperature was measured with infrared thermography for holes 1, 15, and 30. Drilling time, prolongation of drilling time over successive uses, and maximum substrate temperature were compared between control and test bits in each substrate. Drilling time was significantly reduced with test bits in both substrates. Drilling time over successive osteotomies increased more slowly with test bits than with control bits. Test bits generated significantly lower substrate temperatures during drilling. Bits with the carbon nanofilm completed osteotomy faster and generated less heat than control bits. Test bits also had less degradation of drilling performance with repeated use.
... Studies have focused on mechanical complications after internal fixation with cephalomedullary nails (CMNs), particularly on cut-out [3,4]. Enhanced mechanical stability with the cement augmentation method has been demonstrated in several biomechanical studies [5,6]. Therefore, fixation using CMNs with additional cement augmentation (CA) has been developed as a novel treatment option for the osteosynthesis of trochanteric fractures in osteoporotic bones [7][8][9][10]. ...
Article
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Fixation using cephalomedullary nails (CMNs) with additional cement augmentation (CA) was developed as a novel treatment option for the osteosynthesis of osteoporotic trochanteric fractures, though the effectiveness of CA on early postoperative mobility remains uncertain. This multicenter prospective cohort study aimed to estimate the effectiveness of CA on early postoperative mobility in patients with trochanteric fractures. We enrolled patients with femoral trochanteric fractures aged >60 years who were able to walk independently before the injury. The primary outcome was the postoperative 3-day cumulated ambulation score (CAS); the secondary outcome was the visual analog scale (VAS) pain score at rest and during movement on postoperative days 1–3. The outcomes of the patients treated using CMNs with or without CA were compared. Sixty-three eligible patients were categorized into CA (n = 32) and control (n = 31) groups. In univariate analysis, the CA group had significantly higher CAS values, lower VAS scores at rest on day 1 postoperatively, and lower VAS scores during movement on day 3. In multivariable linear regression analyses, the CA group had significantly higher CAS values (beta, 2.1; 95% confidence interval, 0.5 to 3.6; p = 0.01). The CA group had a negative adjusted beta value in their VAS scores during movement. This study indicated that CA was associated with a high CAS value in patients with geriatric trochanteric fractures. However, CA was not associated with pain reduction at rest and during movement during the initial postoperative days.
... 26 Stoffel at al. reported an increased risk of cement penetration into the hip joint, leading to severe clinical complications such as rapid osteoarthritis onset. 14 Administering the cement through the loosened implant, as performed by some authors, 15,21,27 could again induce high pressure and increase the probability of complications. However, some authors placed the cement around the whole implant, as it was done in the presented study. ...
... The PFNA was widely proved to be a reliable implant to fix femoral intertrochanteric fractures, [5,6,11,12] and the augmentation of the helical blade gives the fixation construct much more stability due to a large bone-implant interface. [13,14] The helical blade theoretically enhances local bone quality via impaction, removes less bone than a lag screw, and touts greater surface area to resist superior cut-out. [8,9] So significant as the blade is, once loosened, the whole internal fixation fails. ...
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Rationale: Femoral intertrochanteric fracture happens easily in the elderly, especially those with osteoporosis. As a standard intramedullary fixation implant, Proximal Femoral Nail Anti-rotation (PFNA) is applied to various types of stable or unstable intertrochanteric fractures of femur. Due to blade-related factors, such as cutting-through into the hip joint, cutting out or back out, there are endless postoperative failure cases of internal fixation, but reports about perioperative failure that the helical blade cannot be tightened are lacking. In this case, we firstly report an intraoperative blade compression failure and an effective technique to help surgeons out of the dilemma by using cannulated hexagonal screwdriver which was already included in the orthopedic instrument box. Patient concerns: An 81-year-old lady suffered left hip pain, swelling and limitation of activity, after slipping and falling when she was in the toilet. Diagnoses: X-ray and computed tomography (CT)-scan showed comminuted left intratrochanteric fracture with a Jensen classification of IIa type. Interventions: The patient was treated by closed reduction and internal fixation with PFNA. We suffered an unprecedented problem that helical blade cannot be tightened by the blade impactor as usual. For fear of helical blade disintegration during removal and a significant decrease in pullout strength after reinsertions, we eliminated the dilemma by using a cannulated hexagonal screwdriver to tighten the "problem" helical blade. Outcomes: The "problem" helical blade was finally locked by using the SW4.0 mm cannulated hexagonal screwdriver which was already included in the instrument box. The operation ended successfully after completing subsequent steps. Lessons: The cannulated hexagonal screwdriver is an effective instrument that can help surgeons out of the dilemma when the blade impactor fails to tighten the helical blade in PFNA implantation.
... 9 The increase of RPAL in the augmented group might be explained by how the cement augmentation had improved the mechanical stability of the fixation construct, especially in the severe osteoporotic bone, resulting in a significant postoperative reduction of pain on weight-bearing ambulation and, therefore, ensuring early functional recovery. 31,39,40 Nevertheless, although the present study demonstrated that the cement augmentation with PFNA is significantly associated with the higher rate of RPAL in these elderly patients, the findings are not comparable with the previous study by Abbreviations: ASA, American Society of Anesthesiologist; BMI, body mass index; CI, confidence interval; CKD, chronic kidney disease; COPD, chronic obstructive pulmonary disease; GFR, glomerular filtration rate; IHD, ischemic heart disease; OR, odds ratio; PRC, packed red cell; MVA, multivariate analysis; UVA, univariate analysis. a n ¼ 121. ...
Article
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Introduction: Postoperative outcomes in the elderly patients with intertrochanteric fracture were generally poor with a low rate of return to prefracture ambulatory level (RPAL). Recent studies showed that proximal femoral nail antirotation (PFNA) with cement augmentation might be useful for postoperative functional recovery. This study aimed to compare the outcomes in elderly patients with high surgical risk, American Society of Anesthesiologist (ASA) grade 3 or 4, who sustained intertrochanteric fractures and were treated with PFNA with and without cement augmentation, and to correlate perioperative surgical factors with the RPAL. Methods: A retrospective consecutive series was conducted based on 135 patients with prefracture ambulation classified as independent in community with or without a single cane (68 in augmented group and 67 in control group). Perioperative data and data on the complications within 1-year postsurgery were collected and compared. Predictive factors for RPAL were analyzed via logistic regression analysis. Results: The overall 1-year postoperative mortality rate was 10% (n = 14) with no significant difference between groups (P = .273). The proportion of elderly patients with RPAL in the augmented group was significantly higher than for those in the control group (48% vs 29%, P = .043). Via univariate analysis, ASA grade 4 (P = .077), history of stroke (P = .035), and use of cement augmentation (P = .041) were correlated with RPAL. However, multivariate regression analysis showed that ASA grade 4 (odds ratio [OR] = 0.40, 95% confidence interval [CI]: 0.18-0.90, P = .026) and use of cement augmentation (OR = 2.72, 95% CI: 1.22-6.05, P = .014) were the significant predictors for RPAL. Discussion and conclusions: The results of the present study showed that PFNA with cement augmentation is safe and effectiveness in the intertrochanteric fracture treatment of elderly. Postoperative functional recovery, like RPAL, in elderly patients who sustained intertrochanteric fractures is relatively low, especially in those with ASA grade 4. However, cement augmentation with PFNA might be helpful for increasing the RPAL in high-surgical-risk geriatric patients.
... However, the presence of severe osteoporosis can considerably increase complication rates due cut out of the hip screw in the femoral head with consecutive varus collapse (Weil et al., 2008). This typical complication of geriatric i.e. osteoporotic proximal femoral fractures is directly related to local bone mineral density (BMD) (von der Linden et al., 2006;Stoffel et al., 2008). Helical-shaped femoral neck blades have been developed to address this problem by improving implant anchorage and increasing cut-out resistance in a weak bone stock (Lenich et al., 2006;Strauss et al., 2006;Gardner et al., 2007). ...
Article
The objective of this study was to investigate primary stability of the proximal femoral nailing antirotation for the indication of unstable medial femoral neck fractures. The device was compared to the dynamic hip screw blade, which is a "gold standard" in the treatment of proximal femoral fractures. Six pairs of human cadaver femurs were tested in a cyclic loading model with loads up to 200 N, 400 N, 600 N, 800 N, and 1000 N, respectively. Iliotibial tract was simulated by a chain that applied forces on the greater trochanter during loading. In vitro combined axial and bending loads were applied. Angular displacements during loading were recorded in all directions, and loads to failure were recorded. For the cyclic loading test no statistically significant differences between the two groups could be detected. Specimens fixed with the dynamic hip screw blade showed higher displacements in the varus direction at 400 N and 600 N, in the external rotation at 200 N, 400 N and 600 N, and in the anterior direction at 400 N. Load to failure revealed no statistical difference between the two implants. The proximal femoral nailing antirotation achieves primary stability comparable to the dynamic hip screw blade. The proximal femoral nailing antirotation combines the biomechanical favorable concept of intramedullary fixation with a minimally invasive surgical technique, which theoretically may be advantageous in clinical use. Further biomechanical studies are required to clarify to what extent the results of the present study can be transferred to the clinical situation.
... Th e requirement for augmentation of bone during orthopedic surgery is a common scenario. [1][2][3][4][5][6] Internal stabilization of fractured or otherwise mechanically destabilized bone oft en occurs in the presence of compromised bone quality. Placement of hardware into bone of reduced mechanical competency can signifi cantly aff ect the performance of the fi xation hardware, and ultimately the clinical outcome. ...
Article
We evaluated the mechanical properties of a novel fiber reinforced calcium phosphate at time zero and after 12 weeks in vivo using a sheep long bone osteotomy model. Time zero data were obtained and compared by pullout testing of 4.5 mm bone screws from bone proper and overdrilled defects of 4.5 and 8 mm diameter. Defects were augmented with: polymethylmethacrylate (PMMA), calcium phosphate, and fiber reinforced calcium phosphate using cadaveric sheep tibiae. Twelve-week data were obtained from explanted tibiae of sheep that underwent unilateral tibial osteotomy surgery repaired with a locking compression plate. The most distal hole was overdrilled to 4.5 or 8 mm diameter, filled with fiber reinforced cement, drilled, tapped and a 4.5 mm screw was placed. Screw holding strength at t= 0 was significantly higher for reinforced when compared to nonreinforced cement, but not different from bone or PMMA in 4.5 mm defects. There was no difference in pullout strength for the 8 mm defect data. After 12 weeks fiber reinforced pullout strength increased by 45% and 8.9% for 4.5 and 8 mm defects, respectively, when compared to t= 0 testing. Fiber reinforced calcium phosphate bone cement can be drilled and tapped to support orthopedic hardware for trauma applications.
... [20,21] Geriatrik kırıklarda osteoporoz nedeniyle ortaya çıkan tespit probleminin çözümü için önerilen bir diğer teknik, kırık sahasına değil ama vidaların osteoporotik kemiğe tutunmasını artırmak için kemik çimentosu kullanılmasıdır. [22] ...
... The possibility of cut-out still persisted and some authors proposed cement augmentation of the sliding hip screw. 23 The limitations of this study are the small size of the study group and the non-randomization of the patients. Moreover, all the data were obtained from CT scans that were done for the investigation of non-orthopedic disorders and which incidentally provided information for analysis the purposes of this study. ...
Article
Computed tomography (CT) is currently considered to be an accurate method for evaluating bone density. We evaluated the CT measurements of bone density using the Hounsfield units (HUs) in 23 patients who had been operated in the past for an extra-capsular hip fracture. Twelve patients were treated with a dynamic hip screw and 11 with a proximal femoral expandable hip nail. All the CTs had been performed for non-orthopedic purposes. Bone density with a region of interest (ROI) could be assessed for both hips. We compared the bone density between the operated versus the non-operated sides as well as between the two surgical groups. Bone density was higher in the hip peg (the femoral component of the expandable nail) side 262.5 (range, 169-351) HU, compared to the opposite non-operated side and to the hip screw group 194 (range, 99-283) HU. The hip screw side had decreased bone density compared to the opposite non-operated side. We were able to define a density index and a difference index: both were higher in the hip peg group. These findings persisted over time. It would be interesting to speculate that increased bone density around an expandable peg provides better fracture stabilization and probably faster healing than a dynamic hip screw.
... Bone cement has been accepted for the treatments in patients with osteoporotic intertrochanteric fracture [34,35]. Dynamic hip screws (DHS) reinforced with bone cement has a satisfying effect in reducing the total displacement of intertrochanteric fracture and enhanced the rotational stability of proximal fragment [36], promoted faster pain relief and improved fracture healing [35]. The geometry of PFNA helical blade is different from other internal fixations. ...
Article
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Background: There are concerns regarding initial stability and cutout effect in proximal femoral nail antirotation (PFNA) treating intertrochanteric fractures. No study have used finite element analysis (FEA) to investigate the biomechanics. This study aimed to compare the cutout effect, stress and displacement between stable (AO31-A1.3) and unstable (AO31-A2.2) intertrochanteric fractures treated by cement augmented PFNA. Methods: Four femoral finite element models (FEMs) were constructed and tested under the maximum loading during walking. Non-augmented and augmented PFNA in two different intertrochanteric fractures were respectively simulated, assuming Tip Apex Distance (TAD) < 25 mm within each FEM. The cutout effect, stress and displacement between femur and PFNA were compared in each condition. Results: Cutout effect was observed in both non-augmented femoral head and was more apparently in unstable intertrochanteric fracture model. After reinforced by bone cement, no cutout effect occurred in two models. Stress concentration were observed on medial part of intertrochanteric region and the proximal part of helical blade before augmented while were observed on femoral shaft and the conjunction between blade and nail after augmented in both FEMs. Displacement mainly appeared on femoral head and the helical blade tip before augmented while distributed moderately on intertrochanteric region and the upper part of nail after augmented in both FEMs. The maximum stress and displacement value of femur decreased both in stable and unstable model after augmented but was more significantly in the unstable one. The maximum stress and displacement value of PFNA increased both in stable and unstable model after augmented but was more significantly in the unstable one. Conclusion: Our FEA study indicated that the cement augmentation of the PFNA biomechanically enhances the cutout resistance in intertrochanteric fracture, this procedure is especially efficient for the unstable intertrochanteric fracture.
... Whereas arthroscopic suture anchor repairs commonly fail at the suture-tendon interface (Cummins and Murrell, 2003), bone-anchor integrity is compromised in osteoporotic bone, weakening the suture anchor fixation strength (Chung et al., 2011;Tingart et al., 2004;Yakacki et al., 2010). Researchers have studied several techniques for improving fixation of implants in osteoporotic bone by using cement (Braunstein et al., 2015;Klos et al., 2010;Sermon et al., 2012aSermon et al., , 2012bStoffel et al., 2008), but only Braunstein et al. showed that cement augmentation can improve fixation strength in rotator cuff repairs specifically. Braunstein et al. used an augmentation technique in which the anchor hole was predrilled and injected with polymethylmethacrylate cement before the anchor was "potted" into the injected cement. ...
Article
Background: We evaluate a novel method of rotator cuff repair that uses arthroscopic equipment to inject bone cement into placed suture anchors. A cadaver model was used to assess the pullout strength of this technique versus anchors without augmentation. Methods: Six fresh-frozen matched pairs of upper extremities were screened to exclude those with prior operative procedures, fractures, or neoplasms. One side from each pair was randomized to undergo standard anchor fixation with the contralateral side to undergo anchor fixation augmented with bone cement. After anchor fixation, specimens were mounted on a servohydraulic testing system and suture anchors were pulled at 90° to the insertion to simulate the anatomic pull of the rotator cuff. Sutures were pulled at 1 mm/s until failure. Findings: The mean pullout strength was 540 N (95% confidence interval, 389 to 690 N) for augmented anchors and 202 N (95% confidence interval, 100 to 305 N) for standard anchors. The difference in pullout strength was statistically significant (P < 0.05). Interpretation: This study shows superior pullout strength of a novel augmented rotator cuff anchor technique. The described technique, which is achieved by extruding polymethylmethacrylate cement through a cannulated in situ suture anchor with fenestrations, significantly increased the ultimate failure load in cadaveric human humeri. This novel augmented fixation technique was simple and can be implemented with existing instrumentation. In osteoporotic bone, it may substantially reduce the rate of anchor failure.
Article
Background: In trauma surgery, lag screws are commonly used. However, in osteoporotic bone, anchorage can be considerably compromised. This study investigates the biomechanical potential of cement augmentation in terms of improved fixation. Methods: 36 Surrogate osteoporotic bone specimens were utilised in three biomechanical experiments, each comparing 6 augmented with 6 non-augmented samples. Standard partially-threaded lag screws (Synthes) were placed following surgical standard. For the augmented groups, 0.4 ml of polymethylmethacrylate was injected into the pre-drilled hole prior to screw placement. Interfragmentary compression was determined using a cannulated ring compression sensor. Maximum torque was recorded with a torque wrench. Compressive relaxation after 24 h, relaxation after loosening and re-tightening the screw as well as maximum compression and torque at failure were measured. Findings: Mean relaxation was significantly lower for the augmented group (p < 0.01). After 24 h, a remaining fragmental compression of 62 % for the augmented and 52 % for the non-augmented specimens was found. Loosening and re-tightening of the screw did not affect the compressive relaxation when augmentation was applied (p = 0.529), compared to an increased relaxation after re-tightening in the non-augmented group (p = 0.04). The mean maximum compression and torque until failure were significantly higher for the augmented group (p < 0.001). Interpretation: Cement augmentation of lag screws can improve fixation stability in terms of installing and maintaining interfragmentary compression. Effects of relaxation can be reduced and re-tightening of screws is possible without compromising the fixation. Particularly in reduced bone mass, augmentation of lag screws can markedly increase the security of the technique.
Article
Pertrochanteric fractures are a rising major health-care problem in the elderly and their operative stabilisation techniques are still under discussion. Furthermore, complications like cut-out are reported to be high and implant failure often is associated with poor bone quality. The PFNA(®) with perforated blade offers a possibility for standardised cement augmentation using a polymethylmethacrylate (PMMA) cement which is injected through the perforated blade to enlarge the load-bearing surface and to diminish the stresses on the trabecular bone. The current prospective multicentre study was undertaken to evaluate the technical performance and the early clinical results of this new device. In nine European clinics, 59 patients (45 female, mean age 84.5 years) suffering from an osteoporotic pertrochanteric fracture (Arbeitsgemeinschaft für Osteosynthesefragen, AO-31) were treated with the augmented PFNA(®). Primary objectives were assessment of operative and postoperative complications, whereas activities of daily living, pain, mobility and radiologic parameters, such as cement distribution around the blade and the cortical thickness index, were secondary objectives. The mean follow-up time was 4 months where we observed callus healing in all cases. The surgical complication rate was 3.4% with no complication related to the cement augmentation. More than one-half of the patients reached their prefracture mobility level within the study period. A mean volume of 4.2ml of cement was injected. We did not find any cut-out, cut through, unexpected blade migration, implant loosening or implant breakage within the study period. Our findings lead us to conclude that the standardised cement augmentation using the perforated blade for pertrochanteric fracture fixation enhances the implant anchorage within the head-neck fragment and leads to good functional results.
Article
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Osteoporotic fractures represent one of the most common cause of disability and one of the major voice in the health economic budget in many countries of the world. Fragility fractures are especially meta-epiphyseal fractures, in skeletal sites with particular biomechanic characteristic (hip, vertebrae), complex and with more fragments, with slow healing process (mineralization and remodeling) and co-morbidity. The healing of a fracture in osteoporotic bone passes through the normal stages and concludes with union of the fracture although the healing process is prolonged. Fractures in the elderly osteoporotic patients represent a challenge to the orthopaedic surgeons. Osteoporosis does not only increase the risk of fracture but also represents a problem in osteofixation of fractures in fracture treatment. The major technical problem that surgeons face, is the difficulty to obtain a stable fixation of an implant due to osteoporotic bone. The load transmitted at the bone-implant interface can often exceed the reduced strain tolerance of osteoporotic bone.IN THE TREATMENT OF OSTEOPOROTIC FRACTURES IT IS IMPORTANT TO CONSIDER DIFFERENT ASPECTS: general conditions of elderly patient and comorbidity, the reduced muscular and bone mass and the increased bone fragility, structural modifications as medullary expansion.The aim of surgical treatment is to obtain a stable fixation that reduces pain and permits an early mobilization.
Article
We studied 80 patients (56 females) with an average age of 84 years (range 80-94). All patients were suffering from osteoporosis (1 or 2 Singh score) and had an unstable intertrochanteric fracture, defined as a fracture with three fragments or more. Patients were divided in group A (40 patients), treated by a cement augmentation technique and group B (40 patients) treated by Gamma Nail conventional technique. Augmentation was performed with MetilMetacrilate (Mendec Spine, Tecres) inserted through the cannulated cephalic screw at its apex. Such parameters were evaluated as the length of operating time, early functional recovery using the Harris hip score, assessment with radiography of the TAD index and development of implant related complications. The HHS average score was 48.2 and 49.31 after 1 month post-operation, 54.37 and 53.56 after 3 months, 54.71 and 56.42 after 6 months, 57.91 and 59.86 after 12 months, in groups A and B, respectively. The average drop of haemoglobin was 1.55 g/dL and 1.05 g/dL, in groups A and B, respectively. Except one joint penetration with the guide wire and some small amount of cement leakage, no other complications (infection, screw cut out and femoral head necrosis) were observed. We believe that in femoral intertrochanteric fractures cement augmentation could improve the mechanical stability of the implant, ensuring early functional recovery.
Article
Despite the good and reliable results of the dynamic hip screw (DHS) for stable fracture patterns, complications of excessive sliding of the lag screw and inadequate bone anchorage occur frequently in elderly patients with unstable intertrochanteric fractures. Although polymethylmethacrylate (PMMA) bone cement has been widely used as a secondary fixation to facilitate fixation stability, there has been no prospective study on the clinical significance of PMMA cement to prevent these two complications in unstable fracture patterns. A prospective study was conducted. The DHS was applied either with or without PMMA cement augmentation in 108 elderly patients. The Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association fracture classification was 31-A2 in 91 patients and 31-A3 in 17 patients. The average age of the patients was 81.9 years (range, 75-96 years). The average follow-up period was 13.9 months (range, 12-30 months). PMMA cement was injected precisely into the proximal fragment with an average amount of 13.7 mL (range, 10-19 mL) in 55 patients. All but six patients (5.6%) had eventual bone union, and the average time to union was 18.1 week (range, 12-36 weeks). Screw sliding, femoral shortening, and varus collapse of the proximal fragment were all significantly reduced in the cemented group at the 1-year follow-up (p < 0.001, p < 0.001, p < 0.001, respectively). The mean hip pain score was 1.9 (range, 1-4) in all 102 patients and was significantly lower in the cemented group (p = 0.008). One patient with a deep infection in the cemented group and five patients with lag screw penetration in the noncemented group received a total hip replacement. All 18 patients with malunion were in the noncemented group. Of these 18 patients, 14 patients (77.8%) had excessive sliding of the lag screw. The overall complication rate was significantly higher in the noncemented group (p < 0.001). With the meticulous augmentation technique demonstrated in this study, the PMMA cemented DHS proved to have better outcome than a conventional DHS for unstable intertrochanteric fractures in elderly patients. Typical complications related to a conventional DHS device for the treatment of such fractures were successfully prevented.
Article
Background: Cemented augmentation of osteosynthesis for the treatment of peritrochanteric fractures in elderly patients has been under discussion for years. We propose this option as a salvage procedure in cases of instability after standard osteosynthesis. Material and methods: After reduction and optional re-osteosynthesis a Jamshidi needle is placed transcutanously or through the open wound cranio-lateral of the tip of the hip screw. Cement augmentation can be performed under fluoroscopic control. The patients were monitored for at least 7 months postoperatively to rule out a redislocation. Results: From 1/2009 to 1/2011 we treated 6 patients (5 female, 1 male, age 83.8 [79-94] years). We performed 4 augmentations and 2 augmentations with additional re-osteosynthesis. OP time was 26.8 (13-45) minutes. The revision was performed 9.7 (4-14) days after the osteosynthesis. Within 14.7 (7-28) months no redislocation and no surgical complication occurred. Conclusion: Even with a small patient number the good results show the potential of this minimally invasive technique. In our opinion this option allows a fast and technically easy salvage procedure without blocking of further treatment options like a prosthesis.
Article
Management of impending pathologic femoral neck fractures includes internal fixation, arthroplasty and megaprostheses. The study aim was to determine the augmentative effect of cement injection for minimally invasive treatment of femoral neck lesions. Twenty-seven cadaveric femora received a simulated osteolytic lesion previously shown to decrease the femur's failure load by 50%. Specimens were allocated to three groups of nine and loaded to failure in simulated single-leg stance: (1) percutaneous cementation + internal fixation (PCIF); (2) percutaneous cementation (PC); and (3) internal fixation (IF). Lesion-only and augmented finite element models were virtually loaded and stresses were queried adjacent to the lesion. PCIF resulted in the largest failure load though the increase was not significantly greater than the PC or IF groups. Inspection of the PC and PCIF specimens indicated that the generation of a cement column that spanned the superior and inferior cortices of the femoral neck increased failure loads significantly. Finite element analysis indicated that IF and PCIF constructs decreased the stress adjacent to the lesion to intact femur levels. Cementation without superior-to-inferior femoral neck cortical contact did not restore proximal femoral stress toward the intact condition. Internal fixation alone and internal fixation with or without cementation produce similar levels of mechanical augmentation in femora containing a high-risk lesion of impending fracture. A cement injection technique that produces a cement column contacting the superior and inferior femoral neck cortices confers the highest degree of biomechanical stability, should percutaneous cementation alone be performed.
Article
Introduction: Proximal femoral fractures will gain increasing importance in the future due to the epidemiological development. Osteoporosis is often a limiting factor in the achievement of implant stability. New nailing systems offer the possibility of augmentation of the femoral neck component with cement. The aim of this study was to perform a biomechanical comparison of implant stability in osteoporotic pertrochanteric fractures using the proximal femoral nail antirotation (PFNA, Synthes GmbH, Umkirch, Germany) with cement augmented and non-augmented blades. Materials and methods: Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DEXA) in six pairs of fresh-frozen human femurs. Standardised pertrochanteric fractures (AO31-A2.3) were treated with a PFNA. Cement augmentation was performed in six constructs. Axial loading was applied according to a single-leg-stance model using a hydraulic testing machine increasing to 1400N over 10,000 cycles. Biomechanical comparisons between the two groups that were comparable concerning BMD, tip-apex-distance and native stiffness were made with regard to postoperative stiffness, survived cycles, load to failure, failure mechanism and axial displacement. Results: The stiffness of all stabilised femurs was significantly lower than for native specimens (native 702.5±159.6N/mm vs. postoperative 275.4±53.8N/mm, p<0.001). Stiffness after instrumentation was significantly greater for the cement augmented group than for the non-augmented group (300.6±46.7N/mm vs. 250.3±51.6N/mm, respectively, p=0.001). Five of the twelve constructs survived cyclic testing. Statistically significant differences of the BMD were detected between survived and failed constructs (0.79±0.17g/cm(2) vs. 0.45±0.12g/cm(2), respectively, p=0.028). The failure loads for specimens surviving 10,000 cycles were 4611.9±2078.9N in the cement augmented group (n=3) and 4516.3N and 3253.5N in the non-augmented group (n=2). Postoperative stiffness was found to be a positive predictor of maximum force to failure (R(2)=0.83, p=0.02). Conclusions: The results of this biomechanical study show that cement augmentation of the PFNA increases the implant stability in osteoporotic pertrochanteric fractures. Further studies are necessary to evaluate this procedure in providing long term clinical results.
Article
The augmentation of fixation with bone cement is increasingly being used in the treatment of severe osteoporotic fractures. We investigated the influence of bone quality on the mechanics of augmentation of plate fixation in a distal femoral fracture model (AO 33 A3 type). Eight osteoporotic and eight non-osteoporotic femoral models were randomly assigned to either an augmented or a non-augmented group. Fixation was performed using a locking compression plate. In the augmented group additionally 1 ml of bone cement was injected into the screw hole before insertion of the screw. Biomechanical testing was performed in axial sinusoidal loading. Augmentation significantly reduced the cut-out distance in the osteoporotic models by about 67% (non-augmented mean 0.30 mm (sd 0.08) vs augmented 0.13 mm (sd 0.06); p = 0.017). There was no statistical reduction in this distance following augmentation in the non-osteoporotic models (non-augmented mean 0.15 mm (sd 0.02) vs augmented 0.15 mm (sd 0.07); p = 0.915). In the osteoporotic models, augmentation significantly increased stability (p = 0.017). Cite this article: Bone Joint J 2013;95-B:1406–9.
Article
Osteoporotic fractures of the distal femur (primary as well as periprosthetic) are a growing problem in today's trauma and orthopaedic surgery. Therefore, this feasibility study should identify the biomechanical potential of a (commercially available) spiral blade in the distal femur as compared to a single screw without any additional plate fixation. Additionally, the influence of cement augmentation was investigated. An artificial low density bone model was either instrumented with a perforated spiral blade or a 5 mm locking screw only. Additionally, the influence of 1 ml cement augmentation was investigated. All specimens were tested with static pull-out and cyclic loading (50 to 250 N with an increment of 0.1 N/cycle). In the non-augmented groups, the mean pull-out force was significantly higher for the blade fixation (p < 0.001). In the augmented groups, the difference was statistically not significant (p = 0.217). Augmentation could increase pull-out force significantly by 72 % for the blade and 156 % for the screw, respectively (p = 0.001). The mean number of cycles to failure in the non-augmented groups was 12,433 (SD 465) for the blade and 2,949 (SD 215) for the screw, respectively (p < 0.001). In the augmented group, the blade reached 13,967 (SD 1,407) cycles until failure and the screw reached 4,413 (SD 1,598), respectively (p < 0.001). The investigated spiral blade was mechanically superior, significantly, as compared to a screw in the distal femur. These results back up the further development of a distal femoral blade with spiral blade fixation for the treatment of osteoporotic distal femur fractures.
Article
The benefits of cement augmentation with fixation of osteoporotic pertrochanteric fractures have been previously demonstrated. The objective of this study was threefold: 1. Quantify the intra-osseous pressure produced during cement augmentation of the perforated PFNA blades. 2. Assess whether the pressure generated is influenced by the injection rate. 3. Assess the amount of force applied during the injection. Six pairs of human cadaveric femurs were used in the study. A basicervical osteotomy was performed and the heads were instrumented with the PFNA blade. Each pair was randomly assigned into one of two groups: slow vs. rapid injection with polymethylmethacrylate (PMMA) cement. In the slow group, the augmentation was done using 6 consecutive 1ml injections, each over 10 seconds. In the rapid group each 1ml injection was carried out over 5 seconds. For intra-osseous pressure measurements, transmitters were inserted to a depth of 5mm at both the superior and inferior apices of the head. The reaction forces on the syringe were measured as well. There were no significant differences between the slow and rapid injection rates with respect to the peak pressures measured at the 6 time points immediately following cement injection. In both groups, elevations in pressure were transient and returned to baseline values within 30 seconds. The highest pressure recorded in the slow group was 37.3mmHg and 30.7mmHg in the rapid group. The force required after each sequential injection increased in both groups; however, significantly higher forces were required to inject cement over 5 than 10 seconds (P=0.036). This in-vitro model is the first one to demonstrate that femoral head cement augmentation is associated with a small transient increase in intra-osseous pressure with sequential fast and slow 1ml injections of up to 6 ml PMMA. We conclude that cement augmentation of the perforated PFNA blade carries a low risk of pressure induced avascular necrosis.
Article
Objective The aim of this study was to evaluate the holding strength of cannulated screw with multiple holes on threaded area, supported with PMMA in femoral head. Material and methods A total of 48 human femoral heads were divided into two groups after mineral density measurement with Q-CT. Seven-millimeter cannulated screws with multiple holes on threaded area supported with PMMA were used in the study group, while in the control group standard 7-mm cannulated screws were used. Each group was divided into three subgroups with eight femoral heads. Mineral density of each subgroup was equal to the other. Groups were compared in terms of pull-out, maximum extraction torque and cut-out. Results In pull-out group, maximum holding strength (N) was measured, while axial pull-out of 0.5 mm/sec applied with Instron. Results showed meaningful significant difference (p
Chapter
Implant augmentation aims to increase the implant to bone surface and to reduce the stresses on the trabecular structures. Augmentation is performed by the injection of small amounts of PMMA through the implant. The additional stability has been shown in biomechanical and clinical studies on Dynamic Hip Screw (DHS) augmentation and on proximal femoral nail augmentation. The decision for augmentation is made after implantation of the helical blade and is based on the clinical judgement of the bone strength of the femoral head during blade insertion by the surgeon. The only contra-indication for proximal femoral nail augmentation is a perforation of the femoral head by the Kirschner-wire or by the helical blade because this would lead to cement leakage in the hip joint. Until now, there is only limited clinical experience. All fractures showed callus formation, no osteonecrosis of the femoral head or lysis around the blade was noticed and no implant migration like cut-out or cut-through was seen. The data suggest that the rate of complications directly related to implant augmentation is very low when the technique is applied correctly.
Article
Background: Fracture fixation in weak bone is still a clinical challenge. Screw augmentation was shown to successfully increase their primary stability. The currently used calcium phosphate or polymeric bone cements, however, present important drawbacks such as induced toxicity and/or impaired bone neo-formation. A new approach to enhance bone screw primary stability without affecting bone formation is the use of non-setting, calcium phosphate loaded soft materials as the augmentation material. Methods: Two types of biomaterials (non-crosslinked hyaluronic acid as viscous fluid and agar as hydrogel) were loaded with 40 wt/vol% of hydroxyapatite particles and characterized. The screw augmentation effect of all materials was evaluated through pull-out tests in bovine cancellous bone and compared to the non-augmented situation (control). The bone mineral density of each test sample was measured with μCT scans and was used to normalize the pull-out strength. Findings: Both materials loaded with hydroxyapatite increased the normalized pull-out strength of the screws compared to control samples and particle-free materials. This counter-intuitive augmentation effect increased with decreasing bone mineral density and was independent from the type of the soft materials used. Interpretation: We were able to demonstrate that non-setting, injectable biomaterials loaded with ceramic particles can significantly enhance the primary stability of bone screws. This material combination opens the unique possibility to achieve a screw augmentation effect without impairing or even potentially favoring the bone formation in proximity to the screw. This effect would be particularly advantageous for the treatment of osteoporotic bone fractures requiring a stabilization with bone screws.
Article
Biomechanical studies with reliable clinical applicability are challenging to carry out. The results can be heavily dependent on the materials being tested (condition and ages of specimens), environmental conditions (temperature, moisture), magnitude and direction of loading, loading characteristics (static, dynamic), loading cycles and frequency, and how one measures and defines failure. The interested reader gains more confidence in the results and recommendations of a biomechanics study if the methodology reasonably models real-world scenarios and multiple studies from different labs all come to the same general conclusion.
Article
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Background Osteoporotic intertrochanteric fractures often have postoperative complications despite a perfect reduction and an optimal fixation. We describe a simple technique using bone substitute augmentation and hypothesize that this method would prevent excessive sliding of the lag screw and potential subsequent complications. Methods Between January 2009 and July 2017, patients with osteoporotic intertrochanteric fractures who were treated with a dynamic hip screw (DHS) were enrolled in this retrospective cohort study. DHS group patients received conventional DHS treatment and BSA-DHS group patients received bone-substitute augmented DHS treatment. Factors such as demographics, Parker and Palmer mobility scores, health-related quality of life (HRQoL) scores (short-form Health Survey-12 Physical Component Summary [SF-12-PCS], and SF-12 Mental Component Summary [SF-12-MCS]), morbidities, mortality, and radiographic outcomes were compared. Results We enrolled 85 patients: DHS group = 37 and BSA-DHS group = 48. There was significant lag-screw sliding (mean: 9 mm and 3 mm, p < 0.001), varus collapse (mean: 7 degrees and 3 degrees, p < 0.001), and femoral shortening (mean: 10 mm and 3 mm, p < 0.001) in the DHS group compared to the BSA-DHS group. The ability to get around the house was significantly different between the DHS and BSA-DHS groups (p = 0.031) at 3 months. Postoperative scores were not significantly different after 6, 9 or 12 months, however. Scores for the ability to get out of the house and to go shopping and the SF-12-PCS were significantly worse in the DHS group at 3 and 6 months. Malunion and lag-screw cutout were also significantly worse in the DHS group (p = 0.037 and p = 0.033, respectively). Conclusions Bone-substitute augmentation appears effective to prevent typical postoperative complications experienced by the DHS group patients, and to improve functional outcomes. Additional prospective randomized large-scale cohort studies are necessary to confirm this conclusion. Level of Evidence Therapeutic Level III.
Article
Background: An early postoperative mobilisation shows beneficial effects in terms of complications and mobilization scores in older adult proximal femur fracture patients. An adequate load-bearing capacity of the operated extremity is essential for early mobilization. We hypothesize that cement augmentation of the Proximal Femoral Nail antirotation (PFNA) leads to a higher load capacity during postoperative mobilisation compared to a non-cemented PFNA. Methods: Forty-nine orthogeriatric patients with pertrochanteric fractures were enrolled consecutively in a maximum care hospital in a pre–post study design (level of evidence 2). A study group of 25 patients received nailing (PFNA) with additional cement augmentation (CA group), whereas the control group of 24 patients received the same fracture fixation without cement augmentation (NCA Group). All patients participated in a gait analysis using an insole force sensor to measure the loading rate (loadsol®, Novel, Munich, Germany) on the fifth postoperative day. Results: The NCA group showed a mean age of 75,88 years (SD ± 9.62), the CA a mean age of 81,44 years (SD ± 7.77). The most common fracture type was a pertrochanteric fracture in both groups (NCA: n=20, CA: n=21) Both groups showed no differences with regards to the ASA (NCA: 2.67; CA: 2.68) score and the postoperative Parker Mobility Score(NCA: 2.67; CA: 2.68). Patients who received cement augmentation showed a significant (p=0.004) higher loading rate in the postoperative gait analysis. The CA group showed a loading rate of 58.12% (SD ± 14.50) compared to the uncemented PFNA group with 43.90% (SD ± 18.34). Conclusions: Cement augmentation in elderly patients with a proximal femur fracture increased the early postoperative loading rate. Especially in frail patients with poor bone quality cement augmentation should therefore be considered to enhance early mobilization with full weight bearing in order to reduce complications and improve survival.
Article
Background Cut-out of gamma nail often results from poor primary bone stability, suboptimal reduction (varus) and excentric placement of the head element which may lead to “instability” and frequently requires revision. Various studies have shown that augmentation with polymethylmethacrylate cement increases the primary stability of osteosynthesis. However, it has not yet been widely used in fracture treatment due to certain disadvantages, e.g., the lack of osteointegration, the formation of an interface membrane or the presence of toxic monomers. Few studies show that biodegradable bone cements increase the stability of osteosynthesis in different anatomical regions and therefore could be an alternative to polymethylmethacrylate cement in the treatment of pertrochanteric fractures. Methods Two biomechanical situations were simulated using 24 Sawbones (simple and multifragmentary pertrochanteric fractures; AO-classification 31-A1 and 31-A2. Both groups were stabilized using the Gamma3® nailing system with and without biodegradable bone cement. Sawbones underwent the same cyclic loading test, simulating 10.000 gait cycles loading the bones with three times body weight. Migration was determined by comparing computed tomography scans recorded before and after the mechanical testing. The three-dimensional migration of the lag screw was calculated, and the rotation of the head around the longitudinal axis was determined. Findings Biodegradable cement reduced migration by approximately 35% in 31-A1 fractures (25.4% in 31-A2 fractures) and the rotation of the head around the lag screw by approximately 37% in 31-A1 fractures (17.8%, 31-A2). Interpretation Use of biodegradable bone cement improved the primary stability of gamma nail osteosynthesis in the biomechanical model.
Article
The management of pertrochanteric fractures (PTF) in the very elderly relies on early verticalisation to limit complications of the decubitus and this requires stable osteosynthesis allowing immediate full support without risk of mechanical failure. The aim of the study was to analyse the value of cementing the cervicocephalic blade during osteosynthesis with a proximal femoral nail. A prospective bicentric comparative study was con- ducted. Patients over 90 years of age with PTF were included. Centre A used a PFNA (Proximal Femoral Nail Antirotation) nail without blade cementing and Centre B used the same nail with blade cementing. The primary endpoint was the occurrence of disassembly of the osteosynthesis requiring revision surgery. Secondary endpoints were functional out- come (resumption of walking), postoperative pain and duration of surgery. Sixty-four patients were included in Centre A and 23 patients were included in Centre B. Mean age, gender, functional abilities before fracture, fracture type and tip-apex distance were comparable between the groups. Postoperative pain and duration of surgery did not show significant differences between the groups. Four patients operated on with an uncemented PFNA (6.25%) and one patient operated on with a cemented PFNA nail (4.35%) showed early dismantling. The rate of patients returning to walking was significantly higher in the cemented group (p=0.00005). No significant differences in the rate of dismantling were observed between the two groups. However, the group operated on with a cemented PFNA showed better functional recovery with a significantly higher rate of walking recovery.
Article
PurposeIntramedullary nailing is the standard treatment of trochanteric fractures. Mechanical failure such as cut-out and cut-through are associated with high rates of revision surgery, functional impairment, and mortality. The aim of the study was to evaluate the rate of mechanical failure of the cement augmented screws of Trochanteric Fixation Nail-Advanced (TFNA) nails.Patients and methodsA descriptive, retrospective, multi-operator, single-centre study was performed at our level 1 trauma centre between June 2019 and June 2020. Patients were included if they were > 65 years of age, presented with a trochanteric fracture treated with an augmented TFNA nail with 6 months of follow-up. The primary outcome was fixation failure rate (cut-out or cut-through) at three and six post-operative months. Secondary endpoints were intra-operative data, clinical scores, and radiographic analysis.ResultsForty-five patients (38 women and 7 men) were analysed. The mean age was 82.84 years (65–102, 9.50). There were no instances of mechanical failure in our series, after either three or six months of follow-up. No patient exhibited cut-out or cut-through.The mean amount of cement injected was 4.72 mL (3–6; 1.05). The mean length of surgery was 37.59 min (25–55; 6.48), and the mean intra-operative radiation exposure was 91.47 cGycm2 (25.04–201.81; 51.40) for a mean duration of 43.11 s (17–86; 16.81). The mean duration of hospitalisation was 6.38 days (2–11; 2.27).Conclusions Our clinical results suggest that cement-augmented TFNA screws can be successfully used in the management of trochanteric fractures in patients > 65 years of age.
Article
The Dynamic Hip Screw is well established for the treatment of femoral neck fractures. However, cut-out occurs in 1-6% of all cases. This study compared the biomechanical performance of a helical shaped implant (DHS-Blade) to the Dynamic Hip Screw in an unstable femoral neck fracture model. Ten pairs of human cadaveric femora were either instrumented with a DHS-Blade or a Dynamic Hip Screw. Osteotomies were created using a custom-made saw-guide. Cyclic loading was performed by introducing in vivo measured load-trajectories to the femoral head. Starting at 1500 N, the load was stepwise increased until failure of the construct. Radiographs were taken in 5000 cycles increments to identify onset of femoral head migration with respect to the implant. A survival analysis was performed on the cycles to onset of migration. A paired t-test was carried out on the displacements of the femoral head relative to the shaft as determined by optical motion tracking. One hundred percent migrations occurred for the Dynamic Hip Screw compared to 50% for the DHS-Blade. The survival probability in terms of implant anchorage was found higher for the blade (P=0.023). However, significant higher deformation of the repair construct was observed for the DHS-Blade (P=0.004). The study showed superior implant anchorage of the DHS-Blade compared to the DHS, which might reduce the cut-out risk. Nevertheless, the blade allowed higher deformation of the femur mainly resulting in shortening of the neck, which might be due to a systematic loss of fracture reduction.
Article
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We have prospectively compared the fixation of 100 intertrochanteric fractures of the proximal femur in elderly patients with random use of either a Dynamic Hip Screw (DHS) or a new intramedullary device, the Gamma nail. We found no difference in operating time, blood loss, wound complications, stay in hospital, place of eventual discharge, or the patients' mobility at final review. There was no difference in failure of proximal fixation: cut-out occurred in three cases with the DHS, and twice with the Gamma nail. However, in four cases fracture of the femur occurred close to the Gamma nail, requiring further major surgery. In the absence of these complications, union was seen by six months in both groups.
Article
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Osteoporotic fractures represent a significant burden to society. The costs of osteoporotic fractures to the UK health care system have not previously been accurately described. In this paper, we quantify the health care and social care costs of fractures occurring in women aged 50 years and over in the UK. We used a variety of data sources. For acute hospital hip fracture costs existing published estimates were used whilst for social care costs a survey of resource use among fracture patients before and after hip fracture was utilized. We undertook a case-control study using the General Practice Research Database to estimate primary care costs. From these data we estimated that the cost of a hip fracture is about 12,000 Pounds, with non-acute hospital costs representing the larger proportion. The other fractures were less expensive, at 468 Pounds, 479 Pounds and 1338 Pounds for wrist, vertebral and other fractures, respectively. For all fractures the annual cost to the UK is 727 million Pounds. Assuming each male hip fracture costs the same as a female fracture, including these would increase the total costs to 942 million Pounds.
Article
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The first East Anglian audit of hip fracture was conducted in eight hospitals during 1992. There were significant differences between hospitals in 90-day mortality, development of pressure sores, median lengths of hospital stay, and in most other process measures. Only about half the survivors recovered their pre-fracture physical function. A marked decrease in physical function (for 31%) was associated with postoperative complications. A re-audit was conducted in 1997 as part of a process of continuing quality improvement. This was an interview and record based prospective audit of process and outcome of care with 3 month follow up. Seven hospitals with trauma orthopaedic departments took part in both audits. Results from the 1992 audit and indicator standards for re-audit were circulated to all orthopaedic consultants, care of the elderly consultants, and lead audit facilitators at each hospital. Processes likely to reduce postoperative complications and improve patient outcomes at 90 days. As this was a multi-site audit, the project group had no direct power to bring about changes within individual NHS hospital trusts. Significant increases were seen in pharmaceutical thromboembolic prophylaxis (from 45% to 81%) and early mobilisation (from 56% to 70%) between 1992 and 1997. There were reduced levels of pneumonia, wound infection, pressure sores, and fatal pulmonary embolism, but no change was recorded in 3 month functional outcomes or mortality. While some hospitals had made improvements in care by 1997, others were failing to maintain their level of good practice. This highlights the need for continuous quality improvement by repeating the audit cycle in order to reach and then improve standards. Rehabilitation and long term support to improve functional outcomes are key areas for future audit and research.
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To investigate time trends in mortality after admission to hospital for fractured neck of femur from 1968 to 1998, and to report on the effects of demographic factors on mortality. Analysis of hospital inpatient statistics for fractured neck of femur, incorporating linkage to death certificates. Four counties in southern England. 32 590 people aged 65 years or over admitted to hospital with fractured neck of femur between 1968 and 1998. Case fatality rates at 30, 90, and 365 days after admission, and standardised mortality ratios at monthly intervals up to one year after admission. Case fatality rates declined between the 1960s and the early 1980s, but there was no appreciable fall thereafter. They increased sharply with increasing age: for example, fatality rates at 30 days in 1984-98 increased from 4% in men aged 64-69 years to 31% in those aged > or = 90. They were higher in men than women, and in social classes IV and V than in classes I and II. In the first month after fracture, standardised mortality ratios in women were 16 times higher, and those in men 12 times higher, than mortality in the same age group in the general population. The high mortality rates, and the fact that they have not fallen over the past 20 years, reinforce the need for measures to prevent osteoporosis and falls and their consequences in elderly people. Whether post-fracture mortality has fallen to an irreducible minimum, or whether further decline is possible, is unclear.
Article
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The purpose of the study was to determine the effect of long-term exercise on coronary heart disease, osteoporotic risk factors, and physical fitness parameters in postmenopausal women. Forty early postmenopausal women (age 55.1 +/- 3.3 years) with no medication or illness affecting bone metabolism exercised (high impact aerobic, multilateral jumps, multi-set resistance exercise) for 50 months (EG), while 28 women (age 55.5 +/- 3.0 years) served as a nontraining control (CG). Both groups were supplemented with calcium and cholecalciferol. Bone mineral density (BMD) was measured at the lumbar spine, hip, and forearm by dual energy x-ray absorptiometry. Blood lipids were determined using serum samples, and body composition was determined using the bioimpedance technique. Further, maximum isometric strength was determined (Schnell M3, Schnell Trainer). The BMD at the lumbar spine (+1.0%, p = 0.037) and the total hip (-0.3%, p = 0.194) were maintained in the EG, while significant (p < 0.001) decreases were observed in the CG (lumbar spine -3.2; total hip -2.3%). Differences between both groups were significant (p < 0.001). Significant differences between EG and CG were also observed, respectively, for total cholesterol (-6.1 vs. +3.5%, p = 0.008), HDL-cholesterol (+14.1 vs. -7.1%, p = 0.007), triglycerides (-10.2 vs. +27.5%, p = 0.002), body fat (-3.3 vs. +1.3%, p = 0.041), and waist-hip-ratio (-3.5 vs. +0.2%, p > 0.001). Maximum isometric strength significantly (p < 0.001) increased in the EG, while strength parameters decreased in the CG (-0.5 to -6.4%). Thus, the study demonstrated that multipurpose high-intensity exercise programs significantly affect relevant menopausal risk factors and, therefore, may be individually considered as an alternative to hormone replacement therapy.
Chapter
Trochanteric hip fractures are, in many ways, the paradigm for treatment of musculoskeletal illness in the elderly. These fracture types occur rarely in those younger than 65 years old, and then, usually under circumstances of severe trauma or neoplasm. The challenges presented to the orthopaedic surgeon in the treatment of pertrochanteric hip fractures are many, both in and out of the operating room. Not only does the surgeon contend with osteoporosis and significant fracture comminution in attempting to achieve a stable osteosynthesis in a weightbearing limb, but he or she must be cognizant of the impact of the fracture on the patient with regard to medical well-being, mental vigor, rehabilitation and the potential for ultimate independence.
Article
Purpose: Osteoporosis reveals a higher risk of fractures. Due to the lack of possibilities to anchor fixation elements, fracture treatment often turns out to be complicated. An experimental study served to investigate the extent to which the application of bone cement through a modified gliding screw (Dynamic Hip Screw DHS) would improve the screw anchoring in osteorporotic femoral heads. Methods: Quasi-static compressive and torsional load tests were used to assess the desired improvement of the screw anchoring. Cadaver femur pairs served to compare the cement augmentation to the uncemented contralateral control. Results: The improvement of the holding strength of the screw under static compressive and torsional load depended on the cement flow into the adjacent bone tissue. The filling with additional cement was only successful after having created a small hollow space at the screw tip with a special instrument. Consequently, under compression as well as torsion, the cement application yielded improvements from 17% up to several times as much. Conclusion: In the application of gliding screws in osteoporotic femoral heads, the locally limited cement application through the implant has been shown to be a biomechanical possibility to improve screw fixation.
Article
Purpose of review: The sliding hip screw has been the orthopaedic surgeon's implant of choice for repairing intertrochanteric femur fractures for nearly 30 years. This fixed-angled construct allows for dynamic fracture compression during the postoperative period for most (but not all) intertrochanteric fracture patterns. The successful patient outcomes achieved with the sliding hip screw have made this device the gold standard in intertrochanteric fracture management. Recent findings: Advances in hip fracture surgery with respect to the sliding hip screw are highlighted, focusing on appropriate implant selection, operative technique, and clinical outcomes. The theoretic advantages of new hip screw devices are also detailed. Summary: Despite innovative theoretic developments, the sliding hip screw and side plate continue to be the implant of choice for stable intertrochanteric hip fractures.
Article
ObjectivesStudy the effectiveness of nonpharmacological treatments for osteoporosis.MethodReview and qualitative analysis of the literature concerning the effectiveness of nonpharmacological treatments: physical exercise, rehabilitation aiming to prevent falls, spinal orthosis, and vertebro- and kyphoplasty.ResultsThe level of evidence of the effectiveness of nonpharmacological treatment is unequal on the basis of randomized study. The practice of physical exercise by the ambulatory elderly people and home rehabilitation for those who have previously fallen prevent the occurrence of falls. For institutionalized people, the prevention of falls is achieved by multidisciplinary programs. The use of hip protectors to prevent fracture is controversial. Physical exercises prevent bone loss after menopause and during postmenopausaul and corticosteroid osteoporosis. The effectiveness of mobilization after fracture is not documented. Only one study concerning the use of spinal orthosis after vertebral fracture reports interesting results for pain and disability. No randomized study concerning vertebroplasty or kyphoplasty for osteoporotic vertebral fracture is described.ConclusionThe nonpharmacological treatments of osteoporosis are considered therapeutic means of key importance. They aim at the prevention of falls and bone loss and the reduction of disability after fracture. Only physical exercise and rehabilitation have been shown to be effective in preventing falls or bone loss. Their ability to reduce the incidence of fractures remains to be evaluated.
Article
The Medoff sliding plate was designed to achieve compression along the femoral neck and the longitudinal axis of the femoral shaft theoretically to improve the treatment of intertrochanteric hip fractures. The Medoff sliding plate was compared with a standard compression hip screw in a randomized, prospective study for the fixation of 160 stable and unstable intertrochanteric fractures with an average followup of 9.5 months (range, 6-26 months). Overall, 91 fractures were treated using the compression hip screw and 69 were treated with the Medoff sliding plate. Stable fracture patterns (46) united without complication in both treatment groups. Unstable fractures (114) had an overall failure rate of 9.6%, 14% (nine patients) with the compression hip screw and 3% (two patients) with the Medoff plate; this difference was significantly different. The time to union for the 114 unstable fractures was not significantly different between the two devices. For all patients, no differences in lengths of hospitalization, return to ambulatory status before fracture, postoperative living status, or postoperative pain was observed between the two device groups. Use of the Medoff plate for all fracture types was associated with a significantly higher amount of blood loss and operating time.
Article
Bone quality, initial fracture displacement, severity of fracture comminution, accuracy of fracture reduction, and the placement of the internal fixation device are important factors that affect fixation stability. New high strength cements that are susceptible to remodeling and replacement for fracture fixation may lead to improved clinical outcome in the treatment of hip fractures. Norian SRS is an injectable, fast setting cement that cures in vivo to form an osteoconductive carbonated apatite of high compressive strength (55MPa) with chemical and physical characteristics similar to the mineral phase of bone. It can be used as a space filling internal fixation device to facilitate the geometric reconstruction, load transfer, and healing of bone with defects and/or fractures in regions of cancellous bone. Furthermore, this cement can improve the mechanical holding strength of conventional fixation devices. Use of this material potentially could improve fracture stability, retain anatomy during fracture healing and improve hip function, thus achieving better clinical outcomes. In vivo animal studies have shown the material's biocompatibility, and cadaveric studies have shown the biomechanical advantage of its use in hip fractures. Initial clinical experience (in 52 femoral neck fractures and 39 intertrochanteric fractures) showed the potential clinical use of this innovative cement in the treatment of hip fractures. (C) Lippincott-Raven Publishers.
Article
A retrospective analysis of the outcomes in 360 patients with fractures of the hip showed return to preinjury ambulatory status in 51 per cent. One year after injury 27 per cent of the patients had died and 22 per cent were non-ambulatory. For the first eight months after injury the death rate in the fracture population exceeded that of the population at large, while afterward it was the same. Factors that increased the probability of death and non-ambulation included advanced age, preoperative presence of cerebral dysfunction, and male sex.
Article
Forty-two unstable, four-part intertrochanteric fractures in forty-one patients (seventy-one to 104 years old) with severe osteoporosis were treated by open reduction and internal fixation (Jewett nail or compression screw-plate) supplemented with methylmethacrylate packed into the curetted medullary space. One patient was lost to follow-up, one died of a myocardial infarction at six weeks, and one was excluded because of an unsuspected myeloma found at the fracture site. All patients were sitting up in a chair the day after operation. Full weight-bearing on the limb was started within three weeks by thirty patients and at an average of 118 days by six who had very comminuted fractures. Three patients, non-ambulatory preoperatively, did not walk after operation. Of the thirty-eight fractures followed for from nine to thirty-seven months, thirty-seven healed with no loss of position. One fracture which had been fixed with the nail and cement not extending far enough into the head and neck displaced, and the operation had to be repeated, this time with a successful result. The fractures healed by periosteal new-bone formation. There was no evidence of avascular necrosis or wound complications.
Article
The modes of failure of the sliding hip screw devices were investigated by reviewing 223 cases. There were 35 mechanical failures. Two of these occurred when the components separated in highly comminuted fractures. The use of the locking screw is recommended to prevent this. The other 33 occurred when the device had lost its sliding action. The reasons for this included jamming, insufficient slide being available and additional fixation. To reduce the complication rate it is recommended that any additional fixation (such as cerclage wires) should be used with care to ensure that they do not block the barrel. For patients with short femoral necks, a shorter barrelled version of the device should be used as it would have a greater sliding capacity. Guidelines for its use are given.
Article
In a retrospective review of eighty-two intertrochanteric fractures (twenty-nine stable and fifty-three unstable) in seventy-nine elderly, debilitated patients with associated advanced osteoporosis (Grade III or less by the system of Singh et al.), fifty-six were available for follow-up: twenty-eight that had been treated at the University of Illinois with an approximately anatomical reduction and compression-screw fixation and twenty-eight (in twenty-seven patients) that had been treated at the University of Chicago with an approximately anatomical reduction, compression-screw fixation, and adjunctive methylmethacrylate bone cement in the head-neck fragment. Follow-up analysis after an average of thirty-four months for the group that had augmentation with cement and an average of twenty-six months for the uncemented group showed that for the eighteen stable fractures that could be followed the rates of complications of fixation were the same in the two groups, while for the thirty-eight unstable comminuted fractures that were followed the rate of complications of fixation was lower when adjunctive methylmethacrylate cement was used. Among the unstable fractures, one failure (in twenty-one fractures) in the cement-augmented group and ten failures (in seventeen fractures) in the uncemented group were due to failure of fixation (p less than 0.01). For reasons that are not clear, when the thirty-two patients with a healed fracture who could be evaluated for function were rated using the Iowa hip score, the nineteen who were treated with adjunctive cement had significantly lower scores than did the thirteen who were treated without cement (76 +/- 16.5 compared with 92 +/- 12.1, p less than 0.01).
Article
When treated operatively, mechanical problems associated with intertrochanteric hip fracture include malunion and nonunion. Their frequency and severity are directly related to the mechanical effectiveness of internal fixation, which is determined by 5 independent variables: bone quality, fragment geometry, reduction, implant, and implant placement. While all 5 variables are of importance, bone quality and fragment geometry are the product of the patient and the trauma and cannot be significantly modified by the treating surgeon. Reduction, implant placement, and implant selection are the variables which the surgeon can manipulate. While all 3 are important, implant selection and implant placement are of relatively greater importance than reduction. Implant placement in the biomechanically ideal position for the individual patient is probably the single most important of the 5 variables.
Article
The author reviews the literature concerning internal fixation devices for (per) trochanteric fractures. He then presents the advantages of the sliding compression screw and presents the technical problems, and also some case reports.
Article
Failure of fixation of peritrochanteric fractures that have been treated with a fixed-angle sliding hip-screw device is frequently related to the position of the lag screw in the femoral head. A simple measurement has been developed to describe the position of the screw. This measurement, the tip-apex distance, is the sum of the distance from the tip of the lag screw to the apex of the femoral head on an anteroposterior radiograph and this distance on a lateral radiograph, after controlling for magnification. To determine the value of this measurement in the prediction of so-called cutout of the lag screw, 198 peritrochanteric fractures (193 patients) were studied. The minimum duration of follow-up was three months (average, thirteen months), during which period all of the fractures either healed or had failure of the fixation. Of the nineteen failures that were identified, sixteen were due to the device cutting out of the femoral head. The average tip-apex distance was twenty-four millimeters (range, nine to sixty-three millimeters) for the successfully treated fractures compared with thirty-eight millimeters (range, twenty-eight to forty-eight millimeters) for those in which the screw cut out (p = 0.0001). None of the 120 screws with a tip-apex distance of twenty-five millimeters or less cut out, but there was a very strong statistical relationship between an increasing tip-apex distance and the rate of cutout, regardless of all other variables related to the fracture.(ABSTRACT TRUNCATED AT 250 WORDS)
Article
Internal fixation of unstable intertrochanteric fractures of osteoporotic femurs often leads to complications, which are primarily caused by the mechanically weak bone. The aim of this study was to test whether a new glass-ionomeric cement could reinforce the weak trabecular bone of the femoral head and thus improve the preliminary stability of dynamic hip screws (DHS) used for internal fixation. As a standardized model, a intertrochanteric osteotomy was performed on eight pairs of human, female, cadaver femora; a bony defect was also created medially to diminish support of the femoral neck. To stabilize the osteotomy a 135 degrees DHS was inserted. In one femur of each pair the glass-ionomer cement was applied to see whether this would enhance stability. The elastic and irreversible deformation of the internal fixation was measured at the osteotomy level under a cyclic load of 1400 N applied to the femoral head. In both the cemented and the uncemented cases, the femoral head shifted irreversibly in the caudal direction and tilted into a varus position. Movements of the femoral head in other directions were mainly reversible and small. The irreversible movement of the femoral head was significantly larger, approximately twice as great, following uncemented DHS fixation than after cemented fixation. Most movement occurred during the first ten load cycles; higher load cycles did not increase the irreversible deformation in the cemented group, but in the uncemented group a further increase in deformation was detected. These results indicate that internal fixation of unstable intertrochanteric femoral fractures can be significantly improved by the use of cement.(ABSTRACT TRUNCATED AT 250 WORDS)
Epidemiology is the study of disease in populations. The discipline thus concerns itself with a wide range of issues, from those that relate to the health of individuals (such as the definition of a particular disorder and the characteristics of the individuals who will suffer from it), to those that concern the entire population (for example, the overall morbid and economic consequences of a disorder to society and the means whereby this burden might be reduced). While all of these applications of epidemiology are relevant to osteoporosis, they cannot all be addressed adequately within the constraints of this contribution. Furthermore, some of the issues will be covered in later sections of this volume. The purposes of this review are to provide a working definition of osteoporosis, to summarize the epidemiological data concerning the frequency of osteoporosis and its related fractures, and to determine the impact that the condition has on society. This information will provide a backdrop against which the pathophysiology and treatment of the condition may be discussed in the chapters that follow. However, the review will close with a brief overview of the approaches to prevention that might be adopted in the general population.
Article
The Pauwels' theory of hip biomechanics assuming bending stresses of the proximal femur has been critisized by recent authors. Therefore, the fundamentals of the classic theory have been reviewed, analysed by means of modern methods, and completed. The conclusion is that, hypothetically, a totally bending-free skeletal scaffold could be obtained by muscular tear strings. The analysis of anatomical specimens and considerations on optimisation show, however, that the bending theory of the proximal femur gives still the best explanation for the observations. Furthermore, the classic model has to be completed by two important conditions: 1. The supporting foot must be positioned on the action line of the gravity force of the body, and 2. the abductorial forces on the hip (to balance the momentum of the body weight) is composed by the forces of the lesser glutei (70%) and the muscles tending the tractus iliotibialis (30%).
Article
We report a prospective, randomized, controlled trial, comparing the results of treatment with a dynamic hip screw (DHS) and a gamma nail in 95 consecutive patients with peri-trochanteric fractures of the femur. The DHS was used in 48 patients, the gamma nail in 47. Clinical and radiological outcomes were similar, but the gamma nail was associated with a higher incidence of complications, in particular fracture of the femur below the implant in eight cases. This is consistent with previous reports, and we do not recommend the gamma nail for the treatment of peri-trochanteric femoral fractures.
Article
Clinical spectrum, treatment and short-term outcomes were assessed among the 131 Rochester, Minnesota, men who contracted an initial hip fracture due to moderate trauma during 1978-89. Three-fourths of falls leading to hip fracture occurred indoors with little seasonality, and 91% of fractures were in men 65 years of age or older. The ratio of cervical to intertrochanteric femur fractures was 1.4:1, and there was a tendency toward more neurological conditions among the patients with cervical fractures. Hemiarthroplasty and total hip replacement were mostly performed for cervical fractures, while internal fixation was preferred for intertrochanteric fractures. In-hospital mortality was 11.5%, and the 30-day case fatality rate was 16.0%. Age and postoperative deterioration of mental status significantly increased the risk of early death, the latter even after adjustment in a multivariate model, while comorbidity had a suggestive but not statistically significant influence on mortality. More than half the men were discharged to nursing homes, and 79% of the patients who survived at 1 year resided in nursing homes or intermediate care facilities or were attended by home care. Only 41% of survivors recovered their prefracture level of functioning and nearly 60% of patients limped and required a cane or walker. After implementation of the prospective payment system in 1984, the length of hospital stay was reduced, but there was no change in early mortality rates, in the duration of physical therapy following fracture or in attendance at nursing homes. The results of this population-based study demonstrate the strong impact of hip fractures on short-term outcomes in men.
Article
The ability of calcium phosphate cement (CPC) to reinforce cancellous screws placed in previously stripped holes was studied in vitro. The distal end of canine femurs were harvested. A total of 15 screws were placed in six femurs. The pullout strength (failure force), failure displacement, stiffness, and energy absorbed were determined for the screws in the intact cancellous bone. Next, these stripped screw holes were packed with CPC. The pullout test was repeated, and the results were compared using a paired, Student's t test. We found that the CPC was able to reinforce the previously stripped holes and significantly increase the pullout strength (1,159 +/- 278 N versus 678 +/- 297 N) and the stiffness (1,990 +/- 569 N/mm versus 1,519 +/- 609 N/mm) of the constructs, as well as the energy absorbed by the constructs until failure (467 +/- 180 N.mm versus 278 +/- 140 N.mm). There was no difference in the failure displacement (0.94 +/- 0.23 versus 0.85 +/- 0.51 mm). This study documents the ability of CPC to acutely reinforce cancellous bone screws in a region with no or poor-quality cancellous bone.
Article
One hundred elderly patients who had an intertrochanteric femoral fracture were randomized to treatment with a compression hip-screw with a plate (fifty patients) or a new intramedullary device, the intramedullary hip-screw (fifty patients). All patients were followed prospectively for one year or until death. A detailed assessment of the functional status and the plain radiographs of the hip was performed one, three, six, and twelve months postoperatively. The two treatment groups were strictly comparable. The operative time needed to insert the intramedullary hip-screw was significantly greater than that needed to insert the compression hip-screw with the plate (p = 0.02), but use of the intramedullary hip-screw was associated with less estimated intraoperative blood loss (p = 0.011). The prevalence of perioperative complications, such as bronchopneumonia, cardiac failure, and urinary tract infection, was comparable in the two treatment groups. There were one intraoperative fracture of the femoral shaft and two intraoperative fractures of the greater trochanter in the group managed with the intramedullary hip-screw. One patient had pulling-out of the compression hip-screw on the seventh postoperative day. Four patients had a trochanteric wound hematoma, without infection, after insertion of an intramedullary hip-screw. All but one of the fractures healed. The one non-union, which was in a patient who had a compression hip-screw, was treated with a hemiarthroplasty. The mortality rate was similar in the two treatment groups. The patients who had an intramedullary hip-screw had, on the average, significantly better mobility at one (p < 0.0001) and three months (p = 0.0013) postoperatively. This difference was no longer seen at six and twelve months, although the patients who had an intramedullary hip-screw still had significantly better walking ability outside the home at those time-periods (p = 0.05). The compression hip-screw was removed from two patients because of pain in the mid-portion of the thigh, which had begun after consolidation of the fracture. Fourteen patients who had an intramedullary hip-screw had cortical hypertrophy at the level of the tip of the nail at twelve months postoperatively. Cortical hypertrophy was significantly related to the use of two interlocking screws (p = 0.02). Six of these patients also had pain in the mid-portion of the thigh, and the nail had been locked with two screws in five of them. Three of the six patients had the hardware removed because of the pain, and the symptoms resolved. A seventh patient had pain without cortical hypertrophy. The intramedullary hip-screw device was associated with significantly less sliding of the lag-screw and subsequent shortening of the limb in the region of the thigh (p = 0.012 and 0.019, respectively); these differences were more pronounced when the unstable fractures in the two treatment groups were compared (p < 0.001).
Article
The incidence of hip fractures worldwide is expected to almost quadruple in the next 60 years. Increased cost-containment pressures will focus attention not only on improvements in hip fracture treatment but also on prevention. Three approaches that can prevent hip fractures--preventing falls, preventing and treating bone fragility, and using external hip protectors--are reviewed. Although it is impossible to prevent all hip fractures, these methods may significantly reduce the annual incidence of these fractures.
Article
The most commonly reported failure mode of sliding hip screws in published literature is cut-out of the lag screw. This study investigates the resistance to failure of the femoral head, with lag screws used in two types of sliding hip screws, the gamma locking nail (Howmedica) and the dynamic hip screw (DHS) (Synthes). The investigation consisted of biomechanical tests under static loading conditions on 12 pairs of cadaveric femoral heads, to establish the failure loads due to screw cut-out for the two implant lag screws. The gamma nail appeared to reduce the tendency to cut-out in the osteoporotic bone (soft) associated with elderly patients in whom these devices are commonly used (p < 0.05). In high density bone (hard) the gamma lag screw also appeared to be stronger, because the DHS showed a tendency to bend. The larger diameter of the gamma nail lag screw resists bending and appears to reduce the risk of cut-out compared with the DHS.
Article
Osteoporosis is a major risk factor for fractures in the elderly. Osteoporotic (hip, forearm, and vertebral) fractures today strike hard on Western populations, with a lifetime risk in women similar to the risk for cardiovascular disease. The risk of dying from hip fracture equals breast cancer mortality. Osteoporotic fractures are associated with pain, crippling and social dependency; annual costs in the United States are between $7 to $20 billion, and the contribution from hip fractures is above 60%. Of all hospital beds in Europe, 1 to 1.5% are occupied by osteoporotic patients, a figure expected to more than double during the next fifty years. Whereas vertebral fractures mainly seem to be caused by osteoporosis alone, hip fractures are heavily affected by an age-dependent contributory risk factor, frailty. Frailty might act as an involutionary phenomenon or as comorbidity, particularly neurological; it affects fracture risk along several causal paths, but the increasing frequency and severity of falls are essential. Results of attempts to prevent falls are discouragingly poor. Nevertheless, identification of risk possessors, particularly demented elderly living in institutions, is substantial for directing preventive and treatment programs, mainly acting on general health and on osteoporosis. Frailty of populations increases with longevity. Consequently, projections of fracture occurrence are too conservative. The annual hip fracture incidence in Asia in 2050 might pass 10 million, rather than the hitherto forecasted 3.2 million, thus shifting tomorrow's burden of age-related fractures from the wealthier to the poorer countries. There is an immediate call for vigorous global actions to reallocate resources, to reorganize health care, and to institute high-risk prevention programs.
Article
Osteoporosis reveals a higher risk of fractures. Due to the lack of possibilities to anchor fixation elements, fracture treatment often turns out to be complicated. An experimental study served to investigate the extent to which the application of bone cement through a modified gliding screw (Dynamic Hip Screw DHS) would improve the screw anchoring in osteoporotic femoral heads. Quasi-static compressive and torsional load tests were used to assess the desired improvement of the screw anchoring. Cadaver femur pairs served to compare the cement augmentation to the uncemented contralateral control. The improvement of the holding strength of the screw under static compressive and torsional load depended on the cement flow into the adjacent bone tissue. The filling with additional cement was only successful after having created a small hollow space at the screw tip with a special instrument. Consequently, under compression as well as torsion, the cement application yielded improvements from 17% up to several times as much. In the application of gliding screws in osteoporotic femoral heads, the locally limited cement application through the implant has been shown to be a biomechanical possibility to improve screw fixation.
Article
We have reviewed 178 intertrochanteric fractures treated by dynamic hip screw (DHS) fixation between March 1995 and December 1999 and followed for a minimum of 1 year. We used Singh's classification of the trabecular bone structure in the proximal femur as a measure of osteoporosis and also classified the fractures according to three different systems (Boyd-Griffin, Evans, AO). The postoperative radiographs were examined for loss of reduction, i.e. varus angulation >100, perforation of the femoral head, more than 20-mm extrusion of a lag screw or metal failure. We found 49 cases which showed radiographic failures. Two were stable fractures and 47 unstable fractures (Evans' classification). Unstable fractures with osteoporosis had a failure rate of more than 50%. In such cases DHS should not be the first choice for treatment.
Article
This is the first quantitative study of the impact force over the hips of volunteers who fell laterally from standing to a hard surface while wearing a hip protector. Protector pads were first tested with a drop weigh machine. Piezoelectric sensors were placed on the impact surface to record force-time curves with and without a pad covering the surface. Two types of pads transmitted only 9% of the force at a drop weight impact force of 13,372 N. Sensors were placed over the hip under a protective hip pad worn by 10 volunteers who deliberately fell from standing, to a concrete surface. Only 5% or less impact force was transmitted to the skin sensors, and no hip injuries occurred after 85 falls, providing evidence for the safety of such falls. Only transient skin pain and tenderness occurred in three volunteers. Force transmission through the pads was well below that required to fracture hips from cadavers with osteoporosis in vitro. There was variability in the reduction of force transmission among the volunteer subjects. A 1-month compliance study with 106 elderly subjects showed protector use for 70% to 95% of their hours out of bed.
Article
To evaluate a modified sliding hip screw for the fixation of trochanteric fractures that provides increased fixation strength in osteoporotic bones and allows for the safe intraoperative application of bone cement. Biomechanical cadaver study. Unstable trochanteric fractures were simulated by osteotomy in nine pairs of cadaveric femurs and stabilized by a standard sliding hip screw randomly assigned to the left or right femur. The contralateral femur was stabilized with a newly designed hip screw, which was augmented with low-viscosity bone cement. Femoral bone mineral density was measured by dual x-ray absorptiometry and quantitative computed tomography. Fixation stability of the hip was assessed after dynamic loading by displacement measurement of the femoral head in a simulated one-leg stance configuration. Modification of the hip screw together with cement augmentation significantly (p < 0.05) increased the initial stability of the fracture fixation technique. The total displacement of the femoral head was reduced by 39 percent on average using cement augmentation in the modified screw compared with the standard sliding hip screw. The largest improvement in initial fixation stability was found for the most osteoporotic bones. This modified hip screw augmented with bone cement can significantly enhance the initial fixation stability of trochanteric fractures in osteoporotic femurs.
Article
To compare maximum extraction torque and pull-out load for femoral neck fracture implants inserted with standard technique or after augmentation with polymethylmethacrylate (PMMA) or calcium phosphate cement (Norian SRS). Biomechanical study using synthetic bone. Implants were inserted in foam blocks with three different densities for simulation of normal bone or slight or severe osteoporosis. Tested implants included three screws (AO, Olmed, Hansson), one screw with both threads and a barb (Hybrid), and one pin with a hook (LIH hook-pin). Implants were inserted by standard technique and after augmentation with PMMA or Norian SRS. The effect of (a) density of the synthetic bone (low, medium, high), (b) augmentation (none, PMMA, SRS), and (c) type of implant (AO, Olmed, Hansson, Hybrid, LIH) on the maximum extraction torque and pull-out load was determined using a material testing machine. Analysis of variance with Fisher's PLSD post hoc test was used to determine statistical differences. PMMA significantly increased maximum torque and pull-out load for all implants and block densities when compared without cement (p < 0.0001), whereas enhancement with SRS was far less pronounced and most obvious in low density blocks. For screws normally inserted without predrilling (Olmed and Hansson) the use of SRS in high density blocks caused a significant reduction in maximum torque (p < 0.0001) and pull-out load (p < 0.0001). SRS-augmented specimens failed through the cement at the periphery of the threads, whereas PMMA-augmented specimens failed between the cement and the synthetic bone. This study suggests that augmentation with PMMA around femoral neck fracture implants will increase the holding power significantly when compared with standard insertion technique as well as augmentation with calcium phosphate cement. Augmentation with calcium phosphate cement like SRS will increase the holding characteristics mainly in low density bone, whereas in high density bone it might even reduce the maximum torque because of the need for predrilling when using the cement for augmentation.
Article
A prospective, randomized study comparing the compression hip screw with the Gamma nail in the treatment of 426 intertrochanteric fractures is reported. The median patient age was 80 years, and 71% were women The compression hip screw operation took less time except in Evans Type 5 fractures. Blood loss generally was less in the compression hip screw group except in patients with Type 5 fractures. The most frequent surgical problem for patients in the Gamma group was problems with distal locking. Cephalic position of the femoral head screw and cut-out were seen more often in the Gamma nail group. The Gamma nail more frequently preserved the fracture position obtained perioperatively. Whether there was distal locking of the Gamma nail in unstable fractures did not seem to affect the healing rate. Additional fissures or fractures in the proximal femur occurred during five Gamma nail operations and two compression hip screw operations. Postoperative walking ability did not differ between the groups. At 6 months 88% of the fractures were healed. In less comminuted fractures, the compression hip screw method is the preferred method of treatment whereas the Gamma nail is an alternative treatment for more comminuted Evans Type 5 fractures.