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No difference between lag screw and helical blade for cephalomedullary nail cut-out a systematic review and meta-analysis

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IntroductionCephalomedullary nail (CMN) cut-out is a severe complication of treatment of intertrochanteric femur fractures. This study aimed to identify modifiable risk factors predictive of implant cut-out including: CMN proximal fixation type (lag screw vs. helical blade), tip-apex distance (TAD), reduction quality, nail length, screw location, and surgeon fellowship training.MethodsA systematic review of the published literature was conducted on Pubmed/MEDLINE and Cochrane Library databases for English language papers (January 1st, 1985–May 10th, 2020), with 21 studies meeting inclusion/exclusion criteria. Studies providing quantitative data comparing factors affecting CMN nail cut-out were included, including fixation type (lag screw vs. helical blade), tip-apex distance (TAD), reduction quality, nail length, and screw location. Twelve studies were included and graded by MINOR and Newcastle–Ottawa Scale to identify potential biases. Meta-analysis and pooled analysis were conducted when possible with forest plots to summarize odds ratios (OR) and associated 95% confidence interval (CI).ResultsThere was no difference in implant cut-out rate between lag screws (n = 745) versus helical blade (n = 371) (OR: 1.03; 95% CI: 0.25–4.23). Pooled data analysis revealed TAD > 25 mm (n = 310) was associated with higher odds of increased cut-out rate relative to TAD < 25 mm (n = 730) (OR: 3.72; 95% CI: 2.06–6.72).Conclusion Our review suggests that cephalomedullary implant type (lag screw vs. helical blade) is not a risk factor for implant cut-out. Consistent with the previous literature, increased tip-apex distance > 25 mm is a reliable predictor of implant cut-out risk. Suboptimal screw location and poor reduction quality are associated with increased risk of screw cut-out.Level of evidenceLevel III.
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European Journal of Orthopaedic Surgery & Traumatology (2022) 32:1617–1625
https://doi.org/10.1007/s00590-021-03124-8
ORIGINAL ARTICLE
No difference betweenlag screw andhelical blade
forcephalomedullary nail cutout asystematic review
andmetaanalysis
MitchellNg1· NiharS.Shah2· IvanGolub1· MatthewCiminero1· KevinZhai3· KevinK.Kang1· AhmedK.Emara3·
NicolasS.Piuzzi3
Received: 5 June 2021 / Accepted: 13 September 2021 / Published online: 19 October 2021
© The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature 2021
Abstract
Introduction Cephalomedullary nail (CMN) cut-out is a severe complication of treatment of intertrochanteric femur frac-
tures. This study aimed to identify modifiable risk factors predictive of implant cut-out including: CMN proximal fixation
type (lag screw vs. helical blade), tip-apex distance (TAD), reduction quality, nail length, screw location, and surgeon fel-
lowship training.
Methods A systematic review of the published literature was conducted on Pubmed/MEDLINE and Cochrane Library data-
bases for English language papers (January 1st, 1985May 10th, 2020), with 21 studies meeting inclusion/exclusion criteria.
Studies providing quantitative data comparing factors affecting CMN nail cut-out were included, including fixation type (lag
screw vs. helical blade), tip-apex distance (TAD), reduction quality, nail length, and screw location. Twelve studies were
included and graded by MINOR and NewcastleOttawa Scale to identify potential biases. Meta-analysis and pooled analysis
were conducted when possible with forest plots to summarize odds ratios (OR) and associated 95% confidence interval (CI).
Results There was no difference in implant cut-out rate between lag screws (n = 745) versus helical blade (n = 371) (OR:
1.03; 95% CI: 0.254.23). Pooled data analysis revealed TAD > 25mm (n = 310) was associated with higher odds of increased
cut-out rate relative to TAD < 25mm (n = 730) (OR: 3.72; 95% CI: 2.066.72).
Conclusion Our review suggests that cephalomedullary implant type (lag screw vs. helical blade) is not a risk factor for
implant cut-out. Consistent with the previous literature, increased tip-apex distance > 25mm is a reliable predictor of implant
cut-out risk. Suboptimal screw location and poor reduction quality are associated with increased risk of screw cut-out.
Level of evidence Level III.
Keywords Cephalomedullary nail· Intertrochanteric fracture· Lag screw· Helical blade· Implant cut-out· Tip-apex
distance
Introduction
The incidence of intertrochanteric hip fractures has increased
over recent years [1]. The mainstays for implant fixation of
intertrochanteric fractures include the use of intramedullary
nails or dynamic hip screws [24]. Nonetheless, the gold
standard for treating unstable intertrochanteric hip fractures
is internal fixation with a cephalomedullary nail (CMN) [5].
One of the most common complications of CMN fixation is
cut-out, defined as implant protrusion outside the femoral
head, which can lead to varus displacement [6, 7]. While the
incidence is low, ranging from 1.6 to 4.3% in most studies
[810], implant cut-out is a severe complication associated
with subsequent increased patient morbidity and mortality
* Nicolas S. Piuzzi
piuzzin@ccf.org
1 Department ofOrthopaedic Surgery, Maimonides Medical
Center, 4803 10th Avenue, Brooklyn, NY11219, USA
2 Department ofOrthopaedic Surgery, Case Western Reserve
University, Cleveland, OH45219, USA
3 Department ofOrthopaedic Surgery, Orthopaedic
andRheumatologic Institute, Cleveland Clinic, 9500 Euclid
Avenue, Mailcode A41, Cleveland, OH44195, USA
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... A review of 10 studies, published by Li et al. (2015) reported lower cut-out rates with helical blade compared to lag screw. Another review in 2021 with data from 21 studies suggesting otherwise, reported no difference between two implant types (Ng et al., 2022). In our study, there were no difference between groups in that manner. ...
Article
Full-text available
Objective Cephalomedullary nails (CMN) are implants with a high success rate in the surgical treatment of trochanteric fractures. The aim of this study is to compare the radiological outcomes and mechanical complications of femoral trochanteric fractures treated with three different CMNs. Methods Intertrochanteric fractures in patients aged 50 years and older treated with CMN between January 2016 and December 2021 were reviewed retrospectively. A total of 158 cases meeting the criteria were included to final analysis. Cases were divided into three groups based on the type of nail used (helical blade: group 1, n = 54; screw: group 2, n = 53; winged screw: group 3, n = 51). Demographic characteristics, mechanical complications, reduction quality, tip-apex distances (TAD) and Cleveland zones were compared between the groups. Femoral neck shortening, varus collapse, lag sliding, changes in abductor length were compared between study groups. Factors affecting mechanical complications were also analyzed. Results Study groups were homogenic in terms of demographic characteristics, fracture type and reduction quality. Regarding mechanical complications, no statistically significant difference was found between groups. All three implants had similar outcomes on femoral neck shortening, varus collapse and lag sliding. Pooled analysis of 158 cases showed that mechanical complications increase as the quality of reduction decreases ( p = 0.000) same applies when TAD alters from the desired range ( p = 0.025) and with non-optimally implanted blade according to Cleveland zones ( p = 0, 000). Conclusion The radiological outcomes and mechanical complications of helical blade, screw type blade and winged screw type blade proximal femoral nails are similar in selected group. Regardless of the device type, it is necessary to obtain high reduction quality, obtain TAD within described range and optimally place the blade according to Cleveland Zones to reduce the failure rate and avoid complications.
... There is no strong recommendation for usage of helical blade or lag screw while using TFNA. Although Deichsel 29 et al. reported a rate of 2.6 % medial migration of helical blade in to acetabulum in their series of 153 patients (4 patients had medial migration with a mean migration of 11.6 mm), reports by many other authors 30,31 have shown no significant relation with regards to cutout while comparing helical blade with lag screw. Mitsuzawa et al. have reported that initial fixability of TFNA with augmentation of helical blade has double the surface area and triple the volume than helical blade alone, that can decrease the implant micromotion. ...
... The helical blade was introduced to prevent cut-out by compressing cortical bone during insertion. The most recent clinical evidence has shown that there is no statistically significant difference in rates of cut-out [25]. Other evidence suggests that the helical blade may be beneficial by reducing femoral neck collapse when used in osteoporotic bone [26]. ...
Article
Background Although the majority of intertrochanteric femoral fractures in the United States are now treated with cephalomedullary nailing, it remains uncertain whether differences in clinical performance by nail type exist. The purpose of this study was to compare the aseptic revision rates associated with the 3 most commonly utilized cephalomedullary nails in the United States today: the Gamma nail (Stryker), the INTERTAN (Smith+Nephew), and the Trochanteric Fixation Nail/Trochanteric Fixation Nail Advanced (TFN/TFNA; DePuy Synthes). Methods Using an integrated health-care system’s hip fracture registry, patients ≥60 years of age who were treated with 1 of these 3 commonly used cephalomedullary nail devices were identified. Potential confounders were identified and controlled for, including age, gender, race or ethnicity, body mass index, smoking status, American Society of Anesthesiologists classification, anesthesia type, Elixhauser comorbidities, and the operating surgeon. Multivariable Cox proportional-hazards regression was used to evaluate the risk of aseptic revision (the primary outcome measure) by cephalomedullary nail type, with mortality and revisions unrelated to the index fracture considered as competing events. Results There were 19,215 patients included in the study sample (71.4% female, 77.0% White), including 4,421 in the Gamma nail group, 2,350 in the INTERTAN nail group, and 12,444 in the TFN/TFNA nail group. In the multivariable analysis involving nails of all lengths, the INTERTAN group was found to have a higher risk of aseptic revision compared with the TFN/TFNA group (8-year crude revision rate, 2.9% compared with 1.8%; hazard ratio [HR], 1.62 [95% confidence interval (CI), 1.15 to 2.27]; p = 0.006). The increased risk associated with the INTERTAN nail was primarily seen among the long nails (HR, 1.83 [95% CI, 1.16 to 2.87]; p = 0.009) rather than the short nails (HR, 1.36 [95% CI, 0.87 to 2.11]; p = 0.18). There were no differences in aseptic revision observed between the Gamma group and the TFN/TFNA group. Conclusions In this study of 19,215 patients with a hip fracture treated with cephalomedullary nailing, the INTERTAN nail was found to have a significantly higher risk of aseptic revision. Further research is required to determine whether these results could be related to the unique design of this implant. Level of Evidence Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.
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A set of 3 images including standard AP, standard lateral, and 30° anteromedial oblique projections, was recommended in the operation theater for immediate postoperative fluoroscopies, as routine practice.
Article
Objective The objective of this study was to compare clinical outcomes of patients with trochanteric hip fractures treated with specific different cephalomedullary nail (CMN) designs. Methods A scoping review of the English literature was performed. Inclusion criteria were studies comparing perioperative and postoperative outcomes of trochanteric hip fractures fixated by CMNs for one of the following CMN designs: short versus long nails, blade versus screw fixation, dual versus single lag screw fixation, and application of cement augmentation. Inclusion criteria consisted of human comparative clinical trials (randomized and observational). Exclusion criteria included noncomparative studies, studies comparing CMN with non-CMN devices or with arthroplasty, studies with less than 3 months follow-up, studies that did not provide relevant clinical outcome measures, biomechanical, finite element analyses, animal, or in vitro publications. Data regarding reoperations, peri-implant fractures, mechanical failure, nonunion, infection rates, and functional outcomes were reviewed. Results Twenty-two studies met the inclusion criteria and formed the basis of this study. Failure of fixation rates and reoperation rates for each of the nail designs selected for evaluation is presented, in addition to specific outcome measures relevant to that nail design which was explored: peri-implant fracture—short versus long nails, and specific mechanism of failure—blade versus plate. Conclusions Decreased failure of fixation and reoperations rates were found for integrated dual lag screw fixation. Similar fixation failure and reoperation rates were found for the long versus short nails and for blade versus screw fixation. Level of Evidence Diagnostic, Level IV.
Article
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Intertrochanteric fractures are common injuries around the hip, especially among the elderly. With the rising incidence of these injuries, they are expected to double by 2050. Incidence rates are higher in females than males and in white patients than black African patients. Osteoporosis weakens the local trochanteric anatomic support leading to an increased susceptibility to fractures. Disruption of the posteromedial calcar region results in fracture instability. Optimal lag screw position and fracture reduction are significant determinants for postoperative outcomes. The tip apex distance and reduction criteria determine lag screw cut-out risk and fracture reduction quality, respectively. A calcar-referenced tip apex distance is comparable if not better than the tip apex distance in predicting cut-out risk. Optimal reduction is in slight valgus, a positive medial cortex apposition and smooth anterior cortex apposition. High mortality rates are observed with non-surgical treatment. Surgical management is therefore the gold standard for intertrochanteric fractures. Treatment options are categorised into extramedullary fixation, intramedullary fixation and proximal femur replacement. They include the dynamic hip screw (DHS), cephalomedullary nails (CMN) and arthroplasty. Although still in use, the proximal femur locking plate is falling out of favour due to high complication rates. Fracture stability and pattern influence the treatment choice. There is, however, a growing use of CMNs which has been attributed to surgical training background. Modification of older CMN designs has improved treatment outcomes. Systematic meta-analyses of randomised controlled trials (RCTs) do not show superiority of one treatment option over another; therefore, there is no consensus on the best treatment choice. The proximal femur nail antirotation (PFNA) has better outcomes compared to other fixation options with respect to intraoperative blood loss and Harris hip scores. As a group, CMNs have a better 120-day postoperative quality of life compared to the DHS. No significant difference in complications has been found between treatment options. In light of the anticipated increased incidence of intertrochanteric fracture, more work is needed in planning national resource allocation, devising preventative methods and improving clinical interventions in South Africa. Level of evidence: Level 5
Article
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Background: There is limited information on current cost estimates associated with intertrochanteric hip fractures in the United States. The purpose of the present study was to estimate the incidence and economic burden of both intertrochanteric and all hip fracture types in the Medicare patient population to the U.S. health-care system. Methods: This retrospective database analysis of the 2014 Medicare database involved Standard Analytic File (SAF) 5% sample claims and total enrollment files. Patients ≥65 years of age with a new principal diagnosis of hip fracture (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] code 820.xy) who were continuously enrolled for 18 months were included; those with intertrochanteric hip fracture were further identified with use of ICD-9-CM code 820.21. The total direct medical costs associated with hip fracture in the 90-day and 12-month post-fracture periods were estimated. The relevant costs were estimated on the basis of a propensity-score-matched analysis. The health-care services responsible for major expenses within the 90-day episode-of-care period were also identified. Results: The total annual direct medical costs associated with all hip fractures was 50,508perpatient,resultinginayearlyestimateof50,508 per patient, resulting in a yearly estimate of 5.96 billion to the U.S. health-care system. Intertrochanteric hip fractures accounted for an annual estimate of 52,512perpatient,correspondingtoanoverallannualeconomicburdenof52,512 per patient, corresponding to an overall annual economic burden of 2.63 billion to the U.S. health-care system and representing 44% of all hip fracture costs. Inpatient hospitalization and skilled nursing facility services jointly accounted for 76.3% of the 44,135estimatedcostperpatientand75.644,135 estimated cost per patient and 75.6% of the 42,388 estimated cost per patient within the 90-day post-acute care period for intertrochanteric and all hip fractures, respectively. Conclusions: Hip fracture represents a substantial economic burden to the U.S. health-care system, accounting for $5.96 billion per year, with intertrochanteric hip fracture accounting for 44% of total costs. Level of evidence: Economic and decision analysis, Level IV. See Instructions for Authors for a complete description of levels of evidence. Clinical relevance: The present study provides a comprehensive and updated annual estimate of the economic burden of all hip fracture types and estimates the economic burden of intertrochanteric hip fractures in the Medicare population; to our knowledge, prior availability of this information in the literature is limited.
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Migration profile of helical blades differs from conventional screw design. Tip‐apex distance (TAD) greater than 25mm is associated with early failure in hip screws. This study investigates the effect of a reduced TAD on helical blade fixation. Six pairs of human cadaveric femoral heads were used. Bone mineral density (BMD) was determined by pQCT. Local bone quality was evaluated by breakaway torque. Helical blades were implanted with TAD of 20mm (normal) and 6mm (reduced). Specimens were cyclically tested under progressively increasing physiologic loading at 2Hz with starting peak force of 1'000N, increasing by 0.1N/cycle. Implant migration was monitored by radiographs every 250 cycles. Paired Student's t‐test and Spearman rank correlation coefficient were used for statistical evaluation (p < 0.05). Mean BMD was 246.7mgHA/cm3 SD48.7 (normal), 244.3mgHA/cm3 SD47.6 (reduced);p = 0.93. Mean breakaway torque was 3.59Nm SD2.11 (normal), 3.72Nm SD1.83 (reduced);p = 0.91. Number of cycles to failure (1mm vertical migration) was 16'416 SD7972 (normal), 20'000 SD5232 (reduced);p = 0.38. They correlated significantly with BMD (p = 0.01;R² = 0.91) and breakaway torque (p < 0.049; R² = 0.814) (normal). Breakaway torque correlated significantly with BMD (p = 0.02; R² = 0.898)(normal). In reduced TAD these parameters did not correlate significantly. Normal TAD resulted in failure in varus collapse (n = 6), whereas reduced TAD showed blade perforation (n = 3), rotation (n = 2), varus collapse (n = 1). Fixation stability of helical blades correlates with bone quality when implants are fixed in cancellous bone. Near cortical blade fixation might increase the risk of intraarticular blade perforation. This article is protected by copyright. All rights reserved
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Background Hip fractures are a major worldwide public health problem and includes two main types of fractures: the intracapsular (cervical) and the extracapsular (trochanteric and subtrochanteric) fractures. The aim of this study on patients with trochanteric and subtrochanteric hip fractures was to describe the epidemiology, treatment and outcome in terms of mortality within the context of a large register study. Methods A descriptive epidemiological register study including patients registered in the national Swedish Fracture Register from January 2014 to December 2016. Inclusion criteria were all primary surgically treated traumatic non-pathological trochanteric and subtrochanteric femoral fractures in patients aged 18 years and above. Individual patient data (age, gender, injury location, injury cause, fracture type, treatment and timing of surgery) were retrieved from the register database. Mortality data was obtained via linkage to the Swedish Death Register. Results A total of 10,548 consecutive patients were identified and included in the study. The mean (±SD) age for all patients was 82 ± 11 years and the majority of the patients were females (69%). Most of the fractures were caused by a fall at the same level (83%) at the patients’ accommodation (75%). Fractures were classified using the AO/OTA classification as 31-A1 in 29%, as 31-A2 in 49% and as 31-A3 in 22% of the cases. The most commonly used implant was a short antegrade intramedullary nail (42%), followed by a plate with sliding hip screw (37%). With increasing fracture complexity, the proportion of intramedullary nails was increasing, and also the use of long versus short nails. The majority of the patients were operated within 36 h (90%). There was a higher mortality at 30 days and 1 year for males, and for all those who were delayed to surgery > 36 h. Conclusion Safety measures to prevent fall at elderly patient’s accommodation might be a way to reduce the number of trochanteric and subtrochanteric hip fractures. Surgery as soon as possible without delay should be considered to reduce the mortality rate. The selection of surgical methods depends on the fracture complexity.
Article
Objective: To investigate the association between the tip apex distance (TAD) and migration of helical blade in the femoral head of geriatric intertrochanteric fractures. Methods: A retrospective study of intertrochanteric fractures treated with the proximal femoral nail antirotation (PFNA) between June 2015 and June 2018 was performed. There were 32 males and 55 females with an average age of 84.7 years (range, 80-101 years). All of them were unilateral fresh closed intertrochanteric fractures caused by low energy injury. According to AO/Orthopaedic Trauma Association (AO/OTA) classification, 33 cases belonged to type 31-A1, 35 cases to type 31-A2, and 19 cases to type 31-A3. The time interval from injury to operation was 1-16 days (mean, 3.7 days). The TAD was measured according to immediate postoperative X-ray films. The cases were divided into two groups: group A with TAD less than 20 mm and group B with TAD greater than 20 mm. The difference of fracture healing and migration of helical blade between the two groups were observed. Results: According to the TAD value immediately after operation, 49 patients in group A had TAD of 8.9-19.7 mm, with an average of 18.6 mm; 38 patients in group B had TAD of 20.1-41.4 mm, with an average of 27.7 mm. The 87 patients were followed up for an average of 11.7 months, ranging from 4 to 28 months. Three cases (all in group B) underwent screw blade cutting and displacement, which resulted in internal fixation failure, including 1 case with femoral head cut upward and 2 cases with femoral head penetrated inward. The remaining 84 cases had bone healing without internal fixation related complications such as fracture of internal fixator and fracture of femoral shaft. There was significant difference in the incidence of internal fixation failure between group A and group B ( P=0.049). Conclusion: Reducing the TAD value of helical blade appropriately (15-20 mm) in PFNA internal fixation for intertrochanteric fracture patients over 80 years old can increase initial stability without increasing the risk of helical blade migration.
Article
Objective: To compare functional and clinical outcomes in patients with pertrochanteric hip fractures treated with either a short (SN) or long (LN) cephalomedullary nail. Design: Prospective, randomized. Setting: Clinical investigation was performed at the Mayo Clinic's Level 1 Trauma Center in Rochester, Minnesota. Patients/participants: Two-hundred and twenty patients with intertrochanteric fractures were prospectively randomized to a SN or LN. A total of 168 patients (SN, n=80; LN, n=88) had a mean follow-up of 13.9 months. Fifty-two patients did not meet minimum 3 month follow up. Demographics were comparable between cohorts. Main outcome measurements: The primary outcome measurement was functional outcome evaluated by Short Form (SF-36) and Harris Hip scores (HHS) at 3 months. Secondary outcomes included implant failure, peri-implant fracture, mortality, operative time, estimated blood loss (EBL) and reoperation. Results: SN and LN cohorts were comparable in all aspects of the SF-36. There was a clinically insignificant difference in the HHS between cohorts. Patients treated in the SN cohort experienced shorter operative times but did not differ in tip-to-apex distance or subtrochanteric fracture extension. There was no difference in implant cut-out, deep surgical site infection or peri-implant fractures. Conclusions: Patients treated with SNs or LNs for pertrochanteric femur fractures experienced comparable functional outcomes as measured by SF-36 and HHS. When compared to the LN cohort, SN patients experienced no difference in peri-implant fracture or lag-screw cut-out and tolerated up to 3cm of subtrochanteric fracture line extension. Level of evidence: Therapeutic Level I.
Article
Hip fractures are one of the most common major orthopaedic injuries in the United States, with an incidence that is growing with the aging population. These fractures vary significantly in anatomy, pathogenesis, and treatment. Orthopaedists must be able to carefully distinguish between femoral neck, intertrochanteric, and subtrochanteric femoral fractures because diagnosis is essential in guiding treatment. The extent of complex decision-making and management is often underappreciated in this diverse group of fractures. In this review, the relevant background, anatomy, and current treatment considerations essential to optimize management of these common and significant injuries are discussed.
Article
Background: Cephalomedullary nails are presently the gold standard in management of unstable trochanteric fractures. The tip-apex distance (TAD) is one of the most important factors that determines success or failure of fixation, but was described originally in context of an extramedullary hip screw. Cephalomedullary nails use a different biomechanical approach to fixation; and it is hypothesized that the TAD rule may not apply similarly with these. The aim of this study is to assess whether a high TAD correlates with poor outcomes with cephalomedullary nails, and to elucidate other factors that may predict such outcome. Methods: We retrospectively reviewed the clinical and radiographic records of patients with intertrochanteric fractures, treated at our institution over a 2-year period. Those with unstable fractures (31.A2 and 31.A3), and who were treated with cephalomedullary nails were included in the study. The TAD and the position of the device in the femoral head (Cleveland index) were assessed. Other factors that could influence outcome like age, gender, AO fracture type, restoration of neck-shaft angle and degree of osteoporosis were analysed. Radiographic records of up-to at-least 3 months post-operatively were assessed for complications. Results: After applying the exclusion criteria, 75 patients were included in the analysis. The overall rate of complications was 12%. They occurred in two major patterns - varus collapse and cut-out occurred in 5 patients (6.67%), and device migration in 4 patients (5.33%). The average TAD of patients with cut-out was 28.78 mm, compared to 19.44 mm in those without cut-out (p = 0.002). Our data predicted a cut-off TAD >23.56 mm as most significant for cut-out with cephalomedullary nails. On univariate logistic regression, high TAD (p = 0.009), sub-optimal device positioning (p = 0.02) and poor restoration of neck-shaft angle (p = 0.04) were found to be significant for varus collapse and cut-out, but not for complications relating to device migration. On multivariate analysis, none of the above factors reached statistical significance in isolation. Conclusion: As with extramedullary devices, TAD, along with sub-optimal device positioning and poor restoration of neck-shaft angle is a useful predictor of cut-out even with cephalomedullary nails, negating the initial hypothesis. The above factors in combination have a more significant effect than any one factor in isolation to cause varus collapse and implant cut-out. However these do not affect Z effect, reverse Z effect or other types of device migration seen especially with dual-screw nails.
Article
Introduction: Implant cut-out remains a common cause of cephalomedullary nail (CMN) failure and patient morbidity following surgical treatment of intertrochanteric femur fractures. Recent studies have suggested an increased rate of CMN cut-out with helical blades as opposed to lag screws. We compared rates of overall cut-out between helical blades and lag screws and used bivariate and multivariate analysis to determine the role of proximal fixation method among other variables on risk for cut-out. Subgroup analysis was performed on the basis of failure mechanism; superior migration (Fig. 2) versus medial perforation (Fig. 3). Methods: Three-hundred and thirteen patient charts were retrospectively reviewed over an 8-year period; 245 patients were treated with helical blades and 68 with lag screws. Radiographs were reviewed for fracture pattern, Tip-Apex Distance (TAD), Parker's Ratio (PR) and reduction quality. Rate of implant cut-out was compared between groups and multiple logistic regression was used to analyze the ability of several independent variables to predict implant cut-out. Results: Twenty cut-outs occurred; 15 with helical blades and 5 with lag screws. No difference in the rate of cut-out was observed between the two groups (p = 0.45). Poor fracture reduction was found to be a significant predictor of implant failure via bivariate and multiple logistic regression analysis (p = <0.01, OR 23.573). Helical blade fixation, fracture instability, TAD ≥ 25, and PR ≥ 0.45 were not predictive of implant cut-out during multivariate analysis. Similarly, patient smoking status and surgeon trauma fellowship training did not significantly increase the odds of implant cut-out. Failure by medial perforation occurred in 12 instances, all involving helical blades. Failure by superior migration occurred at a significantly higher rate with lag screws than helical blades (p = 0.02). Conclusion: CMN cutout is likely multifactorial. A direct association between helical blade fixation and implant cut-out was not observed in our study. Amongst modifiable risk factors for implant failure, poorer fracture reduction was predictive of failure by cut-out. Subgroup analysis highlights differing modes of failure between lag screws and helical blades which warrants further investigation. Ideal TAD during helical blade fixation remains unknown.
Article
Introduction: Basicervical femoral neck fractures are challenging fractures in geriatric populations. The goal of this study was to determine whether compression hip screw (CHS) constructs are superior to cephalomedullary constructs for the treatment of basicervical femoral neck fractures. Methods: Thirty cadaver femurs were osteotomized and received a CHS with derotation screw, a long cephalomedullary nail (long Gamma nail), or a short cephalomedullary nail (short Gamma nail). All constructs were loaded dynamically in compression until dynamic failure. Results: All failed CHS constructs demonstrated superior femoral head cutout. In the long Gamma nail and short Gamma nail groups, constructs failed by nail cutout through the medial wall of the trochanter or rotationally. Normalized fluoroscopic distance was found to increase markedly with an increasing cycle count when considering all treatment groups. Conclusions: Given our results and those of previous studies, we could not determine superiority of one implant and recommend that surgeons select fixation constructs based on the individual patient's anatomy and the surgeon's comfort with the implant.