Headless Compression Screw Fixation of Jones Fractures

Abstract

Category: Sports Introduction/Purpose: There remains controversy over the ideal implant for intramedullary screw fixation of fifth metatarsal Jones fractures. Promising results have separately been reported for both indication-specific partially threaded screws and headless compression screws. The purpose of this study was to compare clinical and radiographic results between Jones fracture patients treated with indication-specific partially threaded screws to variable-pitched headless compression screws. We also evaluated the association of various patient and fracture characteristics with surgical failure. Methods: We performed a retrospective review and comparative analyses of all Jones fractures treated with primary intramedullary screw fixation by 4 foot and ankle fellowship-trained orthopaedic surgeons at a single institution from 1995 through 2015. Exclusion criteria included concomitant foot or ankle procedures and revision surgery. Charts were reviewed for patient and injury characteristics, implant, and postoperative course. Serial radiographs were examined for fracture classification (Torg and anatomic zone) and radiographic union. Primary endpoint was number of surgical failures, defined as delayed union, nonunion, or refracture. Secondary endpoints included time to each of radiographic union, weight bearing, and pain resolution. Data were analyzed using independent T test, one-way ANOVA, chi-square, and correlation analyses with significance defined as p < 0.05. Results: Fifty-nine feet were reviewed with mean age 30 years and follow-up 9.6 months. Forty-seven received a partially threaded screw (PT) and 12 feet a headless compression screw (HC). The PT group had more failures (10/47, 21.3% vs. 1/12, 8.3%; p=0.31) and more weeks to full weight (4.2 vs. 3.3, p=0.06), without significant differences in time to radiographic union or pain resolution. Most failures were delayed unions. Pooled union rate was 96.6%. Correlated with failure were age (r=0.469, p < 0.001), diabetes (r=0.390, p=0.002), and BMI (r=0.281, p=0.03), without significant correlation for tobacco, gender, or weight. Compared to Torg 1 and 2, Torg 3 fractures had greater time to pain resolution and radiographic union, age, weight, and BMI. No differences were found between zone II and III fractures. Conclusion: To our knowledge, this is the first reported clinical comparison between indication-specific partially threaded screws (PT) and headless compression screws (HC) for treating Jones fractures. This is also one of the largest clinical series on the subject. The two groups had similar clinical and radiographic results, both with high union rates. While most failures were delayed unions that ultimately healed, the 21% failure rate in the PT group is concerning and may warrant further investigation. Increasing patient age, diabetes, and BMI were associated with worse outcomes. These data support headless compression screw fixation as a viable treatment for Jones fractures.