A low-cost digital templating system for total hip arthroplasty.

Acetate templating for total hip arthroplasty (THA) is cumbersome and inaccurate. High cost hampers mainstream use of digital templating despite ease of use and accuracy. The aim of this study was to validate a low-cost digital THA templating system. Low-cost digital templating software was created using C# programming language. On the basis of power calculations, three surgeons templated 20 consecutive anteroposterior pelvis X-rays using this software against an industry standard. Intraclass correlation coefficient for both systems was approximately .90 for component size and femoral neck cut position. Bland-Altman plots demonstrated that both systems predicted actual implant size with similar accuracy. Interrater reliability was not significantly different between the two systems. This low-cost digital THA templating system is up to 12-fold lower in cost than currently available software with similar accuracy.

Does lateral release change patellofemoral forces and pressures?: a pilot study.

BACKGROUND: One complication of TKA is postoperative anterior knee pain. Balancing retinacular tissue tension to improve patellar tracking is essential in preventing pain. Lateral release might help balance tension although the quantitative changes in patellofemoral force and pressure differentials after lateral release are unknown. QUESTIONS/PURPOSES: We asked if there are differences in patellofemoral forces and pressures for knees resurfaced with standard and gender-specific components and whether lateral release changes these differentials. METHODS: We studied six fresh-frozen cadaver knees with native knees and knees that had TKAs with patellofemoral resurfacing using traditional and gender-specific components. The knees were taken through passive ROM, and the means for medial and lateral peak pressure and maximum force were calculated before and after a lateral release was performed. RESULTS: In traditional resurfaced knees, lateral peak pressure was greater than medial peak pressure by 727.6 ± 550.0 kPa and lateral maximum force was greater than medial maximum force by 29.6 ± 15.9 N. Lateral release decreased the pressure (71.4 ± 826.0 kPa) and force (10.0 ± 32.1 N) differentials in the traditional but not in the gender-specific design. In gender-specific resurfaced knees, lateral peak pressure was greater than medial peak pressure by 158.7 ± 360.0 kPa and lateral maximum force was greater than medial maximum force by 15.5 ± 10.4 N. Lateral release increased the pressure (285.7 ± 565.0 kPa) and force (16.8 ± 10.8 N) differentials. CONCLUSIONS: Our preliminary data suggest lateral release is more effective in reducing peak pressure and maximum force differentials in knees resurfaced with traditional standard components than with gender-specific components. CLINICAL RELEVANCE: The lateral release technique might help with tissue balancing when using standard components in TKA.

Treatment of symptomatic greater trochanteric fracture after total hip arthroplasty.

Isolated greater trochanter fractures after total hip arthroplasty are associated with major comorbidities such as debilitating weakness, pain, and dislocation. No definitive standard of care has been established for these fracture. However, it is well known that reestablishing osseous union in these patients is strongly associated with return of functional status. We report a case of an elderly patient with multiple hip revision surgeries now presenting with unilateral greater trochanter fracture. Treatment incorporated the use of a trochanteric claw plate, cerclage wiring, and adjuvant demineralized bone matrix allograft to achieve successful osseous union. This is the first reported use of adjuvant demineralized bone matrix for fixing these fractures.