[Show abstract][Hide abstract] ABSTRACT: Polymethylmethacrylate (PMMA) impregnated with antibiotics is widely used in the treatment of osteomyelitis and infected arthroplasties. With the emergence of resistant bacterial strains, linezolid, which is active against gram-positive bacteria and toward which resistance has been scarce, has been suggested as an alternative. In the current in vitro study, the authors sought to determine and compare the efficacy and elution kinetics of linezolid from PMMA. Polymethylmethacrylate beads impregnated with linezolid, vancomycin, or gentamicin alone and in combinations were placed in suspensions of vancomycin-resistant enterococci, methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, and Staphylococcus epidermidis. The leaching out concentrations of antibiotics and growth inhibitory time in days were recorded. The mechanical strength of cement beads was evaluated in accordance with International Standard 5833. The growth inhibitory time of linezolid was significantly longer than that of vancomycin and gentamicin for methicillin-resistant S aureus, vancomycin-resistant enterococci, and S epidermidis. The combination of linezolid with gentamicin and vancomycin significantly increased the growth inhibitory time compared with either antibiotic used alone. Linezolid alone or in combination with vancomycin and gentamicin showed satisfactory elution kinetics and antimicrobial activity in vitro without compromising the mechanical strength of PMMA. Future research evaluating the in vivo profile of linezolid-loaded PMMA in experimental animals is needed before it can be considered for human use.
[Show abstract][Hide abstract] ABSTRACT: PURPOSE
To evaluate possible accumulation of metal ions in different body tissues of patients after metal on metal (MoM) hip replacement by assessing correlation between blood metal ion levels (BMIL) and MRI signal intensity (SI) of different body tissues.
METHOD AND MATERIALS
61 MRI hip examinations in 54 patients (Male:female, 18:36, average age: 65 years) who underwent either unilateral or bilateral MoM hip replacement (average time from surgery: 4.1 years, range: 1.9-6.1) were retrospectively evaluated independently by an experienced MSK radiologist and an intern. The mean SI in a region of interest (ROI) was measured for periprosthetic pseudotumor collection (PPC), when present, bladder, fat, muscle and air on axial FSE-T2-w, T1-w and STIR sequences on the same slice. SI was defined as signal to noise ratio, i.e. the measured ROI values of tissue, divided by standard deviation of air at the same slice. Reader's results were averaged. Blood levels of chromium and cobalt ions were retrieved from patients' files. Pearson's correlation coefficient was computed to assess the relationship between BMIL and tissue's SI.
PPC was seen in 32 patients (52%), average volume: 82.48 mm3. Average BMILs were: chromium 19.12 ug/L (range: 0.2-108) cobalt 49.46 ug/L,(range: 0.4-310). No correlation was seen between BMILs and the presence of PPC. In the presence of a PPC, positive correlation exists between BMILs and PPCs' volume (cobalt/chromium: r=0.4/0.6, p=0.05/0.001). Negative correlation was seen on STIR between BMILs and muscle's SI: (cobalt/chromium: r=0.4/0.4, p=0.05/0.04); bladder's SI (cobalt/chromium: r=0.5/0.4, p=0.01/0.04) and between cobalt levels and PPC's SI (r=0.4, p=0.05). Positive correlation was found on T1-w SIs. On T2-w, negative correlation was seen between cobalt (but not chromium) levels and fat (cobalt/chromium: r=0.4/0.3, p=0.04/0.2).
Increased MRI SI on T1-w and decreased SI on STIR were correlated with BMILs. This correlation suggests metal paramagnetic effect and thus metal deposition in the evaluated tissues.
Metal toxicity, hypersensitivity and carcinogenicity are causes for concern for patients with metal-on-metal hip replacement.
Radiological Society of North America 2012 Scientific Assembly and Annual Meeting; 11/2012
[Show abstract][Hide abstract] ABSTRACT: Achieving coronal balance during arthroplasty of a valgus knee presents a challenge for the surgeon. Various techniques for lateral release had been described with no consensus among surgeons. We retrospectively reviewed 42 consecutive patients (38 women, mean age 72.7 years, follow-up 42 ± 23 months) with a valgus deformity who were operated while using a posterolateral capsular release as the sole method of lateral release. All knees were successfully balanced, without the need for further release of other structures. Valgus angles improved from 17.5 ± 4.6 degrees (range 11 to 31) to 6.3 ± 2.2 degrees (range 2 to 11) (p < 0.0001), and the knee and functional scores improved from 5.4 ± 17.7 and 24.8 ± 24.7 to 88.2 ± 15.8 and 70 ± 30, respectively (p < 0.0001) at last follow-up. One patient developed transient peroneal palsy after correction of severe deformity. The posterolateral capsule release, which is similar to that of the "inside-out" technique, provides a simple and safe solution for balancing a valgus knee.
The journal of knee surgery 11/2012; 25(5):355-360.
[Show abstract][Hide abstract] ABSTRACT: Templating is now the standard approach for preoperative planning of total joint replacement and fracture fixation. The aim of this study was to assess the accuracy of new software, TraumaCad™, for preoperative planning for total hip replacement.
This software enables the import and export of all picture archiving communication system (PACS) files from local working stations. It can integrate with all PACS systems. We retrospectively reviewed TraumaCad™-generated templates of digitalized preoperative radiographs of 73 consecutive patients.
The acetabular component, measured within ± 1 size, was accurate in 65 patients (89%), and the femoral stem design component was accurate in 70 patients (97%). The accuracy of the femoral size was predicted in 57 patients within 1 size (87%) and in 65 patients within 2 sizes (96%) out of 68 patients in the Corail femoral component group. TraumaCad™ successfully predicts the sizes of femoral and acetabular component and easily integrates with all PACS files.
Archives of Orthopaedic and Trauma Surgery 12/2010; 130(12):1429-32. · 1.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We report a case of recurrent hemarthrosis 1 year following total knee arthroplasty in a patient with no bleeding diathesis, the hemarthrosis was found to be related to, and led to the diagnosis of high grade sarcoma of the proximal tibia. Twenty five years earlier, he sustained a lateral tibial plateau fracture and was treated with open reduction and plating. Sarcoma developing in association with a metallic orthopedic prosthesis or hardware is an uncommon, but well-recognized complication. Sarcomas that occur adjacent to orthopaedic prostheses or hardware are of varied types, but are usually osteosarcoma or malignant fibrous histiocytoma.
The Knee 11/2009; 17(5):365-7. · 2.01 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background: Transient osteoporosis of the hip (TOH) is a rare disease of unknown etiology, affecting middle-aged men, women in the third trimester of pregnancy, and rarely children, adolescents and nonpregnant women. Presenting symptoms are sudden hip pain and limp, initially with unremarkable radiographs and blood tests.
Methods: Forty-eight patients (54 hips) with sudden hip pain were examined. All had radiographs, technetium bone scan and MRI. Increased uptake on bone scan and bone edema in the femoral head and neck on MRI were found in all patients. Five patients diagnosed with other disease processes were excluded from the study. The remaining (37 men, 6 nonpregnant women; 49 hips) were diagnosed with TOH. All had repeated clinical and MRI investigations until resolution of symptoms. Twenty-six patients had bone density measurements (DEXA) of both hips and spine. Mean follow-up was 43 months (range, 12–106 months).
Results: Spontaneous resolution of symptoms occurred in all patients, and all were asymptomatic at final follow-up, although one patient had minor restriction of flexion. Despite the presence of crescent lines on initial MRI in 14 patients, none progressed to osteonecrosis, and crescent lines were not apparent on follow-up MRI. Excellent correlation was found between radiographic bone edema resolution and clinical improvement. DEXA measurements revealed nine men with abnormal bone density despite their relatively young ages.
Conclusion: TOH is a benign disease, does not progress to osteonecrosis, and should be treated conservatively. Crescent lines may initially appear on MRI only to resolve spontaneously. Other diagnoses should be investigated if pain and bone edema persist.
Current Orthopaedic Practice 03/2009; 20(2):161–163.
[Show abstract][Hide abstract] ABSTRACT: To assess the efficacy in providing improved function and pain relief by administering 8 weeks of acupuncture as adjunctive therapy to standard care in elderly patients with OA of the knee. This randomized, controlled, blinded trial was conducted on 55 patients with OA of the knee. Forty-one patients completed the study (26 females, 15 males, mean age ± SD 71.7 ± 8.6 years). Patients were randomly divided into an intervention group that received biweekly acupuncture treatment (n = 28) and a control group that received sham acupuncture (n = 27), both in addition to standard therapy, for example, NSAIDS, cyclooxygenase-2 inhibitors, acetaminophen, intra-articular hyaluronic acid and steroid injections. Primary outcomes measures were changes in the Knee Society Score (KSS) knee score and in KSS function and pain ratings at therapy onset, at 8 weeks (closure of study) and at 12 weeks (1 month after last treatment). Secondary outcomes were patient satisfaction and validity of sham acupuncture. There was significant improvement in all three scores in both groups after 8 and 12 weeks compared with baseline (P < .05). Significant differences between the intervention and control groups in the KSS knee score (P = .036) was apparent only after 12 weeks. Patient satisfaction was higher in the intervention group. Adjunctive acupuncture treatment seems to provide added improvement to standard care in elderly patients with OA of the knee. Future research should determine the optimal duration of acupuncture treatment in the context of OA.
Evidence-based Complementary and Alternative Medicine 01/2009; 2011:792975. · 1.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Prospective clinical study on the effect of total hip replacement surgery (THR) on low back pain (LBP) in patients with severe hip osteoarthritis.
To assess the affect of THR on LBP.
Hip osteoarthritis causes abnormal gait and spinal sagittal alignment and is associated with LBP.
All consecutive adults scheduled for THR in our department due to severe hip osteoarthritis were assessed by an independent investigator before surgery and 3 months and 2 years post-THR. The Harris Hip Score and the Oswestry scores were used to evaluate hip- and spine-related symptoms, respectively, as were visual analogue scales (VAS) and sagittal spinal radiographs.
Twenty-five patients (10 males; age range, 32-84 years) were evaluated. Both spinal and hip pain and function were significantly better following THR. The mean preoperative LBP VAS score of 5.04 was 3.68 after THR (P = 0.006). The mean preoperative Oswestry score of 36.72 was 24.08 after THR (P = 0.0011). Clinical improvement was maintained and enhanced at the 2-year follow-up. The mean hip pain VAS score was 7.08 before THR and 2.52 after THR (P < 0.01). The mean Harris Hip Score was 45.74 before and 81.8 after surgery (P < 0.01). There were no changes in the radiographic measurements.
Both LBP and spinal function were improved following THR. This study demonstrates the clinical benefits of THR on back pain and is the first to clinically validate hip-spine syndrome as hypothesized by Offierski and MacNab in 1983.
[Show abstract][Hide abstract] ABSTRACT: Interlocking intramedullary nails are the gold standard for treating tibial fractures. We compared the clinical and economic factors associated with tibial fracture fixation using either interlocking intramedullary or expandable nails. From 2000 to 2002, 53 patients with 53 diaphyseal tibial fractures of similar characteristics (AO/OTA 42A1-B3) were randomly and prospectively treated with either interlocking (n = 26) or expandable nails (n = 27). Patients were followed for a minimum of 2 years. The mean surgical duration was 104 minutes with interlocking nails and 52.9 minutes with expandable nails. Rehospitalizations were required in 12 patients (46%) and reoperations were required in nine patients (35%) with interlocking nails. Only one patient (3%) with an expandable nail required rehospitalization and reoperation. Union was achieved after 17 weeks (mean) with interlocking nails and 11.5 weeks with expandable nails. The beneficial economic ramifications of using expandable nails were a 39% reduction in overall surgical and hospital expenses. Expandable nails showed important clinical advantages for tibial fracture fixation, and complications related to lengthy operations, reoperations, and rehospitalizations were substantially reduced. Overall treatment cost was substantially lower with expandable nails. Based on these advantages, simplicity in use, and short surgical time, we recommend an expandable nail for treating tibial (AO Type A, B) shaft fractures.
Clinical Orthopaedics and Related Research 03/2007; 455:234-40. · 2.79 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The femoral head expandable peg offers a new concept of bone-device purchase treating proximal femur fractures. We describe the expansion influence on both the periimplant bone properties and the intraosseous pressure.
A 10 x 8 mm cannulated peg consisting of a stainless steel oval-shaped transversely sectioned rod was tested on 13 femoral heads retrieved from patients with subcapital fracture treated by hemiarthroplasty. Normal saline solution was used to expand the diameter of its membrane from 7.8 to 10.5 mm, resulting in abutment of the distal peg to the compacted cancellous bone of the femoral head. The intraosseous pressure was monitored using a 1.4 mm drill-hole.
Dual-energy X-ray absorptiometry and microradiography demonstrated increased periimplant bone density following peg expansion, without significant increase in the intraosseous pressure.
The new implant afforded improved periimplant bone density, less trabecular damage and preservation of bone stock, all contributing to reliable biomechanical support and potentially decreasing the high complication rate following screw fixation in osteoporotic femora. Further studies are needed in order to establish clinical safety and efficacy.
Archives of Orthopaedic and Trauma Surgery 11/2006; 126(8):526-32. · 1.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Discs were cultured during discectomy from patients with back pain, sciatica, and radiologic evidence of disc herniation causing nerve root compression.
To investigate the claim of culpability of bacteria in causing the local inflammatory process seen in patients with disc herniation and radiculopathy.
Bacteria have been cultured from intervertebral discs of patients with sciatica. An infectious etiology for sciatica could have a dramatic effect on treatment options for this common problem.
To minimize the risk of contamination, the surgeon performed processing and culturing procedures intraoperatively under stringent sterile conditions. Immediately following disc excision, the specimens were divided into 4 pieces, and cultured in various aerobic and anaerobic culture mediums that were incubated for 2 weeks.
The 120 specimens from 30 patients underwent bacterial culture growth: 116 were sterile, an 4 aerobic cultures (2 patients) grew coagulase-negative staphylococci, suggestive of contamination.
These results refute the hypothesis that microbial infection plays a role in the pathogenesis of sciatica. It is possible that bacterial growth from discs reported in previous studies was at least partly related to contamination, which we painstakingly avoided by application of rigorous aseptic techniques.
[Show abstract][Hide abstract] ABSTRACT: The diagnosis of posterolateral instability of the knee is often based on a typical indirect mechanism of injury, a history of "giving way" and a positive dial test. Our search of the English literature revealed no mention of including the valgus stress test in the diagnostic protocol for posterolateral instability.
Based on our experience, we hypothesised that a medial collateral ligament (MCL) tear will also produce a positive dial test and that a valgus stress test would provide differential diagnostic information.
The MCL's of 14 fresh cadaveric knees (7 cadavers) were cut to simulate a grade 3 tear, taking care not to damage the medial retinaculum or the posteromedial stabilisers of the knee. The amount of tibial external rotation (the dial test) was measured for each knee before and after transection of the MCL.
The results of the dial test after transection of the MCL were similar to those stemming from a solitary injury to the posterolateral corner. There was a significant increase in external rotation of the knee in 30 degrees and 90 degrees of flexion. More over, external rotation in 30 degrees was significantly greater than external rotation in 90 degrees of knee flexion.
Whenever suspecting a posterolateral complex injury, one has to carefully perform a valgus stress test in 0 degrees and 30 degrees. Although the support of a clinical study is needed in order to make a definite conclusion, the dial test is probably not reliable in the presence of medial instability, and alternative diagnostic measures should be used.
[Show abstract][Hide abstract] ABSTRACT: Magnetic resonance imaging of the knee is greater than 90% accurate in detecting intraarticular disease when performed and interpreted by musculoskeletal magnetic resonance imaging specialists in specialized medical centers. However, independent imaging institutions often offer less expensive services to health insurers. We wondered if the magnetic resonance imaging performed in our community is of equivalent quality and accuracy. We studied a homogenous group of healthy, young, and fit military recruits to represent a cross section of our country's population. We analyzed all knee magnetic resonance images of soldiers who subsequently had primary arthroscopic knee surgery within a 3-month period from 1997-1998. The results were compared with surgical findings of four structures: medial meniscus, lateral meniscus, anterior cruciate ligament, and articular cartilage. Of the 1185 arthroscopies and 633 magnetic resonance images of the knee performed in 14 institutions, 139 paired magnetic resonance imaging arthroscopic reports met our inclusion criteria. The results showed a false positive rate of 65% for the medial meniscus, 43% for the lateral meniscus, 47.2% for the anterior cruciate ligament, and 41.7% for articular cartilage disease when compared with surgical findings. Accuracy rates were 52%, 82%, 80%, and 77%, respectively. Thirty-seven percent of the operations supported by a significant disorder on magnetic resonance imaging were unjustified. Our findings highlight the consequences that may occur when basing medical care on cost rather than quality of care.
Clinical Orthopaedics and Related Research 07/2006; 447:100-4. · 2.79 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To evaluate and present our experience using the expandable nail system for the treatment of acute tibial shaft fractures.
Two level-1 trauma centers-University teaching hospitals.
Fifty-four consecutive patients were treated by this nail system for acute tibial shaft fracture. Two nail diameters were used, 8.5 mm and 10 mm. Operation, hospitalization and healing times, reaming versus nonreaming, isolated versus multiple injuries, and reoperations were recorded and analyzed statistically.
Follow-up was obtained either until fracture healing or for a minimum of 1 year with an average of 14 months (12 to 24). All fractures healed in an average time of 72 days (21 to 204). The average healing times for patients treated with 8.5-mm and 10-mm nails were 77.2 days (27 to 204) and 63.4 days (21 to 121), respectively. Average operative time was 103 minutes (40 to 185) if reamed and 56 minutes (30 to 80) if unreamed. Average healing times were 65.4 days (21 to 190) if reamed and 79.5 days (42 to 204) if unreamed. There were 11 complications (20.4%) related to the nailing: 3 deep infections, 2 superficial infections, 2 bone shortenings of 1 cm secondary to nail protrusion in the knee, 1 compartment syndrome, 1 fracture propagation, 1 distal malalignment, and 1 delayed union. Hardware was removed in 6 patients (3 infections, 2 patients' request and 1 protrusion into the knee), and 1 additional patient underwent exchange nailing due to a delayed union.
The expandable nail offers the theoretical advantages of improved load sharing and rotational control without the need for interlocking screws. This study demonstrates satisfactory healing and alignment for the treatment of tibial shaft fractures using this device. However, caution must be exercised when using this nail in cases of significant comminution and in cases where the fracture pattern involves the more proximal or distal aspect of the tibial shaft.
[Show abstract][Hide abstract] ABSTRACT: The treatment of choice for early mobilization of hip fracture is surgery, which traditionally employs side plates and screws or intramedullary nails. We examined the biomechanical properties of a new proximal femoral nail system. The new expandable Fixion proximal femur nailing (PFN) system, made of stainless-steel alloy, consists of a nail, a peg and an anti-rotation pin. Upon positioning, the nail and peg are expanded to their maximal diameter. The current biomechanical study investigated: nail bending strength and stiffness, fatigue properties and hip peg strength. A cadaveric study that determined the effect of the expandable peg on the femoral head included subsidence testing, pull and torsion testing and intra-osseous pressure (IOP) measurements before and after expansion. Biomechanical properties of the new nail met ASTM F384 guideline requirements. The cadaver study yielded equivalent results for the pullout test between the peg and the hip screw, but found the peg superior in the torsion strength test. IOP during peg insertion and expansion was substantially lower than the threshold pressure that causes avascular necrosis. The biomechanical tests found the new system to be safe and able to provide good abutment of the nail to the bone. We conclude that the Fixion PFN system proved to be an effective proximal femur fracture fixation device.
Journal of Biomechanics 01/2005; 38(1):63-8. · 2.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The incidence of osteoarticular tuberculosis in the knee and other joints is increasing. Three cases of active tuberculous infection in the presence of a total knee prosthesis are presented. The pathology was not diagnosed until the prosthesis had been removed in 2 patients. They underwent antituberculous therapy and revision arthroplasty. In the third patient, the diagnosis was made early. Antituberculous therapy was begun immediately, and the original prosthesis was retained. Good long-term results were achieved in all 3 cases.
The Journal of Arthroplasty 05/2004; 19(3):397-400. · 2.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Joint replacement is associated with massive blood loss. Various techniques have been used to avoid the use of allogeneic blood. One of the techniques used is postoperative salvage and reinfusion of shed blood that was found to reduce the use of banked blood with its potential risk.
We prospectively studied 365 patients who underwent knee joint replacement (TKR) and were divided in two groups. Group A's shed blood (SureTrans System) was collected ( n=194) and reinfused and group B's was not ( n=171, "controls"). Hemoglobin levels before and after the operation were recorded.
Allogeneic blood requirement for TKR decreased by 65% in group A compared to group B. The packed cell/patient index dropped from 0.91 to 0.29 in group 2A. Statistical analysis yielded the odds ratio for blood replacement, a "predicting formula" for blood replacement depending on hemoglobin levels, and a cutoff point for a patient's receiving blood replacement.
We recommend using this system in TKR for decreasing allogeneic blood replacement and potential associated risks. The predicting formula for blood replacement may be a helpful tool when making a decision of whether or not to use the collector system and for whom.
Archives of Orthopaedic and Trauma Surgery 04/2004; 124(2):114-8. · 1.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Unrecognized Galeazzi fracture dislocation of the wrist (distal radius fracture with radioulnar joint disruption) may lead to a high incidence of permanent functional disability and chronic pain. A high index of suspicion, early recognition, and acute treatment of distal radioulnar joint (DRUJ) instability will avoid chronic problems. This review examines the clinical presentation, diagnostic techniques, management and prognosis in children and in adults for this type of lesion.