Comparison of elective implant removal and complication rates between mini and small fragment implants for lateral malleolar fixation.

Abstract

Implant removal after open reduction and internal fixation (ORIF) of ankle fractures is common. Mini-fragment implants have gained popularity for their smaller size, with studies showing similar load to failure to small-fragment implants. We hypothesized mini-fragment implant use for ORIF of the distal fibula is associated with a lower implant removal rate and without an increase in implant failure. In this retrospective review study at two level-one trauma centers, adult patients (>18 years) with a lateral malleolar or bimalleolar fracture were included. Chart review was performed to determine if patients received ORIF of the distal fibula with mini-fragment implants or small-fragment implants. The primary outcome was elective implant removal of the fibular plate. Secondary outcomes included complications requiring reoperation. Five-hundred and five patients were included with a mean age of 50.6 ± 17.8 years old with a mean follow-up of was 75.7 ± 61.0 weeks. Sixty patients (11.9 %) received mini-fragment fixation. The rate of elective distal fibula implant removal for the mini-fragment group was 8.3 % (5 of 60) compared to 10.8 % (48 of 445) in the small-fragment group (p = .66). The complication rate was 6.7 % (4 of 60) for the mini fragment group versus 6.5 % (29 of 445) for the small fragment group (p = 1.00). Logistic regression demonstrated that each additional week of follow-up increased the implant removal rate with the observed odd ratio (OR) of 1.007 (95 % CI 1.002-1.012). Elective implant removal rates and complications requiring reoperation were similar between mini-fragment and small-fragment fixation of distal fibula fractures. The hypothetical benefit of low-profile mini-fragment implants should be balanced with the higher implant cost.