No difference in early outcomes comparing intramedullary versus extramedullary fibular fixation in operative ankle fractures

Abstract

Introduction

The purpose of this study was to compare postoperative complications and outcomes of minimally invasive intramedullary fixation (IMF) versus plate fixation (PF) in the treatment of distal fibular fractures.

Materials and methods

A retrospective review was performed from identifying all consecutive ankle fracture patients aged ≥18-years-old surgically managed between August 2017 to September 2022 at a tertiary care center with minimum 6 months clinical follow-up. Patients were grouped into those receiving intramedullary versus extramedullary fibular fixation. The primary outcomes were relevant demographic factors (diabetes, osteoporosis, charlson comorbidity index [CCI]), surgical time, complication rates, reoperation rates. Secondary outcomes included time to definitive fracture fixation, fracture characteristics (AO/OTA and Lauge-Hansen classification), syndesmotic instability requiring fixation and discharge disposition.

Results

Forty-one IMF patients (average age 55.3 ± 18.1yrs) and 162 PF patients (47.7 ± 17.4yrs) were identified and included in this study. Within the IMF group, 25 patients received IM nailing and 16 patients received percutaneous screw fixation. A greater proportion of IMF patients had diabetes (39 % vs 22 %, p < 0.001), osteoporosis (22 % vs 3 %, p < 0.001), and moderate or severe CCI (41 % vs 23 %, p = 0.017). Surgical time was significantly reduced when using IMF technique (80.4 ± 43.1 min vs 99.1 ± 43.1 min, p = 0.012). Overall complication rates or time to complication did not differ significantly between groups (p = 0.578 and p = 0.082, respectively); however, when sub-stratified, IMF patients trended towards experiencing fewer wound related complications versus PF patients (5 % vs 9 %, p = 0.291). No IMF patients experienced deep or superficial infections and only 2 (5 %) patients experienced wound dehiscence. Reoperation rates(15 % vs 10 %, p = 0.267) and time to fracture union (2.7 ± 2.2 mos vs 3.1 ± 2.0 mos, p = 0.301) did not differ significantly. At final follow-up (IMF: 15.0 ± 12.2 mos vs PF: 28.5 ± 19.5 mos), Olerud and Molander ankle score was significantly higher in IMF compared to PF (87.1 ± 14.2 vs 76.2 ± 22.6, p = 0.002).

Conclusion

Patients in the IMF group at baseline had several comorbid medical conditions that put them at high risk for wound related complications, however, postoperatively they demonstrated higher functional scores and similar complication rates compared to the PF group. It is important to note, however, while we expected a higher rate of wound issues with the PF group, there were no significant differences in infection rates. Either IMF and PF is reliable for fixation and outcomes, and thus with proper soft tissue, biologically friendly technique, either IMF or PF is a reliable choice in the fixation of fibula fractures.

Level of evidence

III, retrospective cohort comparison study.