Nimrod Snir

10-Year Follow-Up Wear Analysis of First-Generation Highly Crosslinked Polyethylene in Primary Total Hip Arthroplasty

Our goal was to report a 10-year follow up of linear penetration rates for HCLPE, and to determine whether a difference exists between penetrations measured on pelvis or hip anterior-posterior radiographs. We reviewed 48 total hip arthroplasties where a first-generation HCLPE liner was used. Femoral head penetration was measured on both AP pelvis and hip radiographs. Total wear and wear rate at 10 years were 1.26 mm and 0.122 mm/y, respectively. The rate decreased significantly after the first 2-3 years, plateauing at a wear rate of 0.05 mm/y for the last 5 years. The AP hip total wear and wear rate were 1.38 mm and 0.133 mm/y respectively, while rates were 1.13 mm and 0.109 mm/y respectively for the pelvis radiographs (P<.05). We found a significant difference in measurements of linear penetration when comparing AP pelvis vs. hip radiographs with lower rates recorded using an AP pelvis.

Clinical Outcomes After Chronic Distal Biceps Reconstruction With Allografts

Background: Chronic ruptures of the distal biceps are often complicated by tendon retraction and fibrosis, precluding primary repair. Reconstruction with allograft augmentation has been proposed as an alternative for cases not amenable to primary repair. Purpose: To investigate the clinical outcomes of late distal biceps reconstruction using allograft tissue. Study Design: Case series; Level of evidence, 4. Methods: A total of 20 patients who underwent distal biceps reconstruction with allograft tissue between May 2007 and May 2012 were identified. Charts were retrospectively reviewed for postoperative complications, gross flexion and supination strength, and range of motion. Subjective functional outcomes were assessed prospectively with the Mayo Elbow Performance Score (MEPS) and Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire. Results: Eighteen patients with adequate follow-up were included in the study. All had undergone late distal biceps reconstruction with allografts (Achilles [n = 15], semitendinosus [n = 1], gracilis [n = 1], or anterior tibialis [n = 1]) for symptomatic chronic ruptures of the distal biceps. At a mean office follow-up of 9.3 months (range, 4-14 months), all patients had full range of motion and mean gross strength of 4.7 of 5 (range, 4-5) in flexion and supination. After a mean out-of-office follow-up at 21 months (range, 7-68.8 months), the mean DASH score was 7.5 ± 17.9, and the mean MEPS increased from 43.1 preoperatively to 94.2 postoperatively (P < .001). The only complication observed was transient posterior interosseous nerve palsy in 2 patients. Additionally, all but 1 patient reported a cosmetic deformity. However, all patients found it acceptable. Conclusion: Late reconstruction for chronic ruptures of the distal biceps using allograft tissue is a safe and effective solution for symptomatic patients with functional demands in forearm supination and elbow flexion. While there are several graft options, the literature supports good results with Achilles tendon allografts. Further studies are needed to evaluate the clinical outcomes of other allograft options.

Long Head of the Biceps Tenodesis With Cortical Button Technique

There are several options for long head of the biceps (LHB) tenodesis and yet no standard of care. This technical note describes a cortical button technique for LHB tenodesis. We have taken the BicepsButton (Arthrex, Naples, FL) for distal biceps acute primary repair and applied it to the LHB. The biceps tenotomy is completed arthroscopically, and a standard subpectoral approach is used. The biceps is pulled out and whipstitched starting at the myotendinous junction and moving proximally. The humerus is drilled in a unicortical manner slightly larger than the tendon, and the button is passed through a small hole to the posterior cortex. A suture through the tendon provides additional fixation strength to the construct. This is an elegant and effective method of tenodesis that uses a smaller-diameter drill hole in the humerus. The goals of LHB tenodesis are to restore function, reduce pain, and improve cosmesis. This technique offers comparable function and cosmesis with the potential advantage of improving postoperative pain outcomes and lowering the rate of complications.

Outcomes of Total Hip Arthroplasty in Human Immunodeficiency Virus-Positive Patients

Today, patients with human immunodeficiency virus (HIV) live long enough to develop chronic degenerative and HIV-associated joint disease. There is a growing population of patients infected with HIV who are candidates for total hip arthroplasty (THA). A total of 31 HIV-positive, non-hemophilic patients undergoing 41 THAs at our institution between 2000 and 2012 were identified. In-hospital medical complications were reported in 5 of 41 hips, all of which resolved prior to discharge. Deep infection developed in 1 of 41 hips and revision was required in 3 of 41 hips. These results suggest that low rates of complications and revision can be achieved in the HIV-positive, non-hemophilic population. We believe that with careful patient selection, THA may improve the quality of life in the HIV-positive population.

Arthroscopic Anatomic Humeral Head Reconstruction With Osteochondral Allograft Transplantation for Large Hill-Sachs Lesions

Anatomic reconstruction of the humeral head with osteochondral allograft has been reported as a solution for large Hill-Sachs lesions with or without glenoid bone loss. However, to date, varying techniques have been used. This technical note describes an arthroscopic reconstruction technique using fresh-frozen, side- and size-matched osteochondral humeral head allograft. Allograft plugs are press fit into the defect without internal fixation and seated flush with the surrounding articular surface. This technique restores the native articular contour of the humeral head without compromising shoulder range of motion. Potential benefits of this all-arthroscopic approach include minimal trauma to the soft tissue and articular surface without the need for hardware or staged reoperation.

Primary vs Conversion Total Hip Arthroplasty: A Cost Analysis.

INTRODUCTION Increasing hip fracture incidence in the United States is leading to higher occurrences of conversion total hip arthroplasty (THA) for failed surgical treatment of the hip. In spite of studies showing higher complication rates in conversion THA, the Centers for Medicare and Medicaid services currently bundles conversion and primary THA under the same diagnosis-related group. We examined the cost of treatment of conversion THA compared with primary THA. Our hypothesis is that conversion THA will have higher cost and resource use than primary THA. METHODS Fifty-one consecutive conversion THA patients (Current Procedure Terminology code 27132) and 105 matched primary THA patients (Current Procedure Terminology code 27130) were included in this study. The natural log-transformed costs for conversion and primary THA were compared using regression analysis. Age, gender, body mass index, American Society of Anesthesiologist, Charlson comorbidity score, and smoker status were controlled in the analysis. Conversion THA subgroups formed based on etiology were compared using analysis of variance analysis. RESULTS Conversion and primary THAs were determined to be significantly different (P<.05) and greater in the following costs: hospital operating direct cost (29.2% greater), hospital operating total cost (28.8% greater), direct hospital cost (24.7% greater), and total hospital cost (26.4% greater). CONCLUSIONS Based on greater hospital operating direct cost, hospital operating total cost, direct hospital cost, and total hospital cost, conversion THA has significantly greater cost and resource use than primary THA. In order to prevent disincentives for treating these complex surgical patients, reclassification of conversion THA is needed, as they do not fit together with primary THA.

Antimicrobial properties and elution kinetics of linezolid from polymethylmethacrylate.

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.

Revision of Failed Hip Resurfacing and Large Metal-on-Metal Total Hip Arthroplasty Using Dual-Mobility Components.

Revision of metal-on-metal (MoM) total hip arthroplasty (THA) or hip resurfacing is associated with high complication rates. The authors propose dual-mobility components as a surgical option and present short- to mid-term results of MoM hips revised with dual-mobility components. Eighteen consecutive hips that underwent revision of MoM THA or hip resurfacing using dual-mobility components were identified. At final follow-up (mean, 17.5 months), the visual analog scale, modified Harris Hip Score, and SF-12 scores had all improved (P<.05, P<.01, and P<.05, respectively). There were no dislocations or other complications. Revision of failed MoM THA or hip resurfacing using a dual-mobility device is an effective strategy.

Incidence of Patellar Clunk Syndrome in Fixed Versus High-Flex Mobile Bearing Posterior-Stabilized Total Knee Arthroplasty

The geometry of the intercondylar box plays a significant role in the development of patellar clunk syndrome. We reviewed the incidence of patella clunk at mid-to-long-term follow-up of a rotating high-flex versus fixed bearing posterior stabilized TKA design. 188-mobile and 223-fixed bearing TKAs were reviewed for complications, incidence of patellar clunk, treatment, recurrence rates, range of motion, and patient satisfaction. Patellar clunk developed in 22 knees in the mobile (11.7%) and in 4 (1.8%) in the fixed bearing group (P<0.001). 23 out of 26 cases resolved with a single arthroscopic treatment and 2 resolved with a second procedure. The mean postoperative range of motion was 122.4°. All but one patient reported overall satisfaction with the index procedure. In contrast with other recent studies we found a significant incidence of patellar clunk in high-flex mobile bearings. Despite the high rate of patellar clunk syndrome, overall patients did well and were satisfied with their outcomes.

Popliteal Cyst Excision Using Open Posterior Approach After Arthroscopic Partial Medial Meniscectomy

Popliteal cysts are known to be associated with intra-articular pathology, which must be addressed to prevent cyst recurrence. Indications for popliteal cyst excision include cases in which the popliteal cyst does not respond to conservative treatment or arthroscopic intervention or cases in which an underlying cause cannot be found. Several techniques have been described to excise these cysts. Traditionally, open techniques have been associated with cyst recurrence. More recently, arthroscopic cystectomy has been described. However, the risk of recurrence persists because arthroscopy may not afford complete surgical excision. This technical note presents an open posterior technique for popliteal cyst excision that allows for better visualization and complete removal of the cyst while minimizing the risk of neurovascular complications and soft-tissue damage. It is a safe, effective, and straightforward method to achieve symptomatic relief for refractory popliteal cysts.