Adding a First Metatarsal Pin to An Ankle Tubular External Fixator Does Not Reduce the Incidence of Early Reduction Loss

Abstract

External fixation with a bilateral frame configuration (delta frame, DF) is a routine approach for treating ankle fractures and dislocations with severe soft tissue damage. The purpose of this study was to evaluate to what extent adding a first metatarsal fixation contributes to the stability of the fixation as evidenced by reduced frequency of early loss of reduction. A retrospective study was performed to compare the rate of early reduction loss in patients treated with a bilateral frame external fixation as part of a 2-stage treatment protocol for periarticular ankle fractures, in a level one trauma center between 2006 and 2016. The cohort was divided into 2 groups according to the frame configuration that had been used: DF only and DF with first metatarsal fixation (DF+1MT). A multivariate analysis assessing risk factors for postoperative loss of reduction was conducted. A total of 67 patients were included in the study, of which 30 underwent fixation by DF and 37 by DF+1MT. Early loss of reduction was recorded in 13 (19.4%) patients, 6 (20%) in the DF group and 7 (18.9%) in the DF+1MT group (p = .576). None of the assessed risk factors reached statistical significance. To conclude, the addition of a first metatarsal pin as an enhancement of external fixation with a delta frame configuration did not reduce the incidence of early loss of reduction. There is no evidence to support the claim that adding this pin contributes to the stability of the fixation in a clinically relevant manner.