Retrospective survival analysis of the use of uncemented modular tapered stems for revision in periprosthetic Vancouver B-type fractures. Is instability a threat to survival?

INTRODUCTION AND OBJECTIVES: Periprosthetic hip fractures show increasing incidence and complexity, representing a challenge for the surgeon. We aimed to evaluate the survival of uncemented modular tapered stems in the treatment of periprosthetic Vancouver B2 and B3 type fractures and review the main complications and factors associated with decreased survival. MATERIALS AND METHODS: We performed a retrospective study of patients submitted to revision arthroplasty for treatment of periprosthetic femoral stem Vancouver B2 and B3 type fractures with an uncemented modular fluted tapered stem (MRP-Titan). Demographic and radiographic parameters were analyzed. The survival rate (free of reoperation) was calculated at 2- and 5-years using the Kaplan-Meier survivorship analysis. RESULTS: Thirty-nine patients were included with a mean age of 73.5 years and a mean follow-up of 5 years. Arthroplasty survivorship at 2 years was 73.7% and at 5 years was 67.5% (mean 8.4 years; range 6.7-10.2). Survivorship was inferior in the patients with episodes of instability (mean 2.5 years; range 0-5.42) (p<0.001). At least one episode of instability occurred in 26.3% of patients and 60% of these patients had a femoral head size 32mm or lower. At least one episode of instability occurred in 71.4% of patients with a greater trochanter fracture (p=0.008). The consolidation rate was 90.6% and the mortality rate was 23.7%. In the group of patients that died, 55.6% were submitted to at least one revision surgery (p=0.044). CONCLUSION: Survivorship of an uncemented modular stem (MRP-Titan) in revision for PHF is significantly reduced by episodes of instability.

Anatomy of the superficial peroneal nerve: Can we predict nerve location and minimize iatrogenic lesion?

OBJECTIVE OF THE STUDY: Knowledge of anatomical variations of the superficial peroneal nerve (SPN) may minimize iatrogenic insults. The aim of the investigation was to perform an anatomical description of the SPN. MATERIALS AND METHODS: Twenty-three embalmed cadaver lower limbs were dissected. RESULTS: The SPN emerged from the crural fascia about 6.3±7.7mm anteromedial to the anterior border of the fibula and 26.8±12.6mm anteromedial and 113.6±43.9mm superior to the tip of the lateral malleolus. The median point of bifurcation into two terminal branches was 13.0mm anteromedial to the anterior border of the fibula and 34.9±14.7mm anteromedial and 81.0±69.0mm superior to the tip of the lateral malleolus. The SPN was found between 5.76% and 7.70% of the individual's height proximal to the tip of the lateral malleolus, with an unpredictable branching pattern over the intermalleolar line. CONCLUSION: A lateral ankle approach over the posterolateral surface of the fibula (posterior to the tip of the lateral malleolus) minimizes the risk of iatrogenic nerve lesion.