Effect of Syndesmotic Implant Removal on Dorsiflexion

Abstract

Background: There is limited evidence that syndesmotic implant removal (SIR) is beneficial. However, many surgeons advocate removal based on studies suggesting improved motion. Methodologic difficulties make the validity and applicability of previous works questionable. The purpose of this study was to examine the effect of ankle dorsiflexion after SIR using radiographically measured motion before and after screw removal utilizing a standardized load.

Methods: All patients undergoing isolated SIR were candidates for inclusion. Dorsiflexion was measured radiographically: (1) immediately before implant removal intraoperatively, (2) immediately after removal intraoperatively, and (3) 3 months after removal. A standardized torque force was applied to the ankle and a perfect lateral radiograph of the ankle was obtained. Four reviewers independently measured dorsiflexion on randomized, deidentified images. A total of 29 patients met inclusion criteria. All syndesmotic injuries were associated with rotational ankle fractures. There were 11 men (38%) and 18 women (62%). The mean, and standard deviation, age was 50.3 ± 16.9 years (range 19-80).

Results: The mean ankle dorsiflexion pre-operatively, post-operatively, and at a 3-month follow-up was 13.7 ± 6.6 degrees, 13.3 ± 7.3 degrees and 11.8 ± 11.3 degrees, respectively ( P = .466). For subsequent analysis, 5 patients were excluded because of the potential confounding effect of retained suture button devices. Analysis of the remaining 24 patients (and final analysis of 21 patients who had complete 3-month follow-up) demonstrated similar results with no statistically significant difference in ankle dorsiflexion at all 3 time points.

Conclusion: Removal of syndesmotic screws may not improve ankle dorsiflexion motion and should not be used as the sole indication for screw removal.

Level of evidence: Level II, prospective cohort study.

Keywords: ankle range of motion; hardware removal; syndesmotic screw.