SLR - December 2020 - Sean M. Kipp

Clinical and Radiological mid- to long-Term Results After Direct Fixation of Posterior Malleolar Fractures Through a Posterolateral Approach 

Reference: Weigelt L, Hasler J, Flury A, Dimitriou D, and Helmy N. Clinical and Radiological Mid- to Long-Term Results After Direct Fixation of Posterior Malleolar Fractures Through a Posterolateral Approach. Arch Orthop Trauma Surg. 2020 Nov;140(11), 1641–1647.

Level of Evidence: Level 4

Scientific Literature Review

Reviewed By: Sean M. Kipp, DPM
Residency Program: McLaren Oakland Hospital – Pontiac, MI

Podiatry Relevance: Ankle fracture injury is of high relevance to podiatric surgeons as we continue to perform these procedures across the country. This study investigates retrospective analysis of surgical fixation of a posterior malleolar fragment with clinical VAS, AOFAS, and radiological post-traumatic osteoarthritis via Van Dijk classification. The authors’ attempted to show the mid- to long-term clinical and radiological outcome after direct fixation of the posterior malleolus through a posterolateral approach. Their hypothesis was that direct repair of posterior malleolar fractures using a posterolateral approach would lead to less development of ankle osteoarthritis.

Methods: This study reviewed the outcomes of 36 patients retrospectively using multiple logistic regression analysis who underwent direct surgical repair of posterior malleolar fractures using a posterolateral approach. There were 24 female and 12 male patients with a mean age of 63 years of age (range 34–80 years) with a mean body mass index of 28.3kg/m2 (range 19.2–41.0 kg/m2). Inclusion criteria included ankle fracture with posterior malleolar fragment (23 AO-44C, 12 AO-44B, and 1 unclassifiable) treated with direct fixation, using a buttress plate and/or screws through a posterolateral approach, and a minimum follow-up of three years. Patients with additional injuries or procedures on the affected ankle were excluded. Clinical outcomes were assessed with the visual analog scale (VAS) and the AOFAS scales.  Post-traumatic osteoarthritis was recorded using the Van Dijk classification system (grade 0-III).

Results: The mean follow-up was 7.9 (range 3–12) years. Immediate postoperative incongruency of more than ≥ 1 millimeter of the posterior malleolus was seen in five cases. Comparison of dorsiflexion and plantarflexion of the injured ankle to the contralateral side showed no statistical differences. The median VAS was 1.0 and median AOFAS score was 96 at final follow-up. Based on the Van Dijk classification system, 89 percent of the patients showed no signs of pre-operative signs of ankle arthritis. Progression to osteoarthritis was seen in 72 percent of the patients at final follow-up and no negative prognostic factors with respect to clinical outcome were detected.

Conclusions: There remains no single gold standard for fixation of posterior malleolar fractures. Ankle range of motion measurements showed no statistically significant difference in ROM when compared to the uninjured side. With direct visualization of fracture reduction, the rate of post-traumatic arthritis can be reduced. Despite a progression of osteoarthritis to the ankle post-operatively in 72 percent of subjects, there were no prognostic factors that could be identified. The authors suggest including CT analysis pre- and postoperatively to see if the accuracy of reduction may lead to a lower rate of progression to post-traumatic arthritis.

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