Adding First Metatarsal Pin to an Ankle Tubular External Fixator does not Provide Additional Stability

External fixation with a tubular system in a delta frame configuration is a common treatment for ankle fractures and dislocations with severe soft tissue damage. One method to increase the stability of the construct is by adding fixation to the base of the first metatarsus. In some cases, reduction loss in noted on post-operative radiographs. The purpose of this study is to evaluate whether adding the first metatarsus fixation contributes to the stability of the fixation as evident by reducing the frequency of early loss of congruency.

Methods: A retrospective study was preformed to compare early loss of reduction in patients treated with external fixation by a tubular system for periarticular ankle fractures in a level one trauma center between 2006-2016. The cohort was divided into two groups according to the surgical treatment administered, delta fame configuration only (DF) vs. delta fame configuration with first metatarsus fixation (DF+1MT).

Results: A total of 67 patients were included in the study, of which 30 underwent fixation by DF only and 37 by DF+1MT. Early loss of reduction was noted in 13 patients (19.4%), of which 6 (20%) were in the DF group vs. 7 (18.9%) in the DF+1MT group (P=0.576).

Conclusions: The addition of a first metatarsal pin to an external fixator with delta frame configuration does not reduce the incidence of early loss of reduction, and thus is insufficient when extra stability is warranted for fixation of unstable periarticular ankle fractures.