Trends in Posterior Malleolus Fixation and Subsequent Syndesmotic Repair in Trimalleolar Ankle Fractures.

Abstract

Objectives: To evaluate treatment trends for trimalleolar fractures, specifically assessing whether increased posterior malleolus fixation was associated with reduced syndesmotic repair.

Methods:

Design: Retrospective cohort analysis.

Setting: PearlDiver (Mariner data set) database (2010-2021).

Patient selection criteria: Patients were stratified according to ICD-9/10 and Current Procedural Technology codes into 4 cohorts based on index procedure: trimalleolar open reduction and internal fixation (ORIF) with posterior lip fixation and syndesmotic repair, trimalleolar ORIF with posterior lip fixation and without syndesmotic repair, trimalleolar ORIF without posterior lip fixation and with syndesmotic repair, and trimalleolar ORIF without posterior lip fixation and without syndesmotic repair. Exclusion criteria included: younger than18 years, pregnancy, prior ankle osteoarthritis, connective tissue disease, or syndesmotic repair unrelated to trimalleolar ankle fractures.

Outcome measures and comparisons: Annual percentage incidence of syndesmotic repair within these cohorts was tabulated and compound annual growth rate (CAGR) and Mann-Kendall analysis was performed to assess trends. χ2 analysis evaluated characteristics associated with posterior fixation.

Results: From 2010 to 2021, the incidence of concomitant posterior malleolus fixation in trimalleolar ORIF increased from 17.6% to 21.4% (CAGR: +6.2%, Mann-Kendall P -value: 0.011). The incidence of trimalleolar ORIF without posterior fixation decreased from 82.4% to 78.6% (CAGR: -3.0%, Mann-Kendall P -value: 0.04). The incidence of syndesmotic repair after trimalleolar fixation increased from 10.1% to 29.3% (CAGR for posterior fixation: +17.0%, Mann-Kendall P -value: <0.001; CAGR for no posterior fixation: +13.1%, Mann-Kendall P -value: <0.001). Trimalleolar ORIF with posterior fixation demonstrated similar rates of malunion, nonunion, and reoperation at 2 years postoperative, with no significant differences on χ2 analysis, compared with those without posterior malleolus fixation.

Conclusions: The incidence of trimalleolar ORIF with posterior lip fixation increased over the past decade, and contrary to the hypothesis, the rate of subsequent syndesmotic repair after trimalleolar ORIF also increased.

Level of evidence: Therapeutic, Level IV. See Instructions for Authors for a complete description of levels of evidence.