Buttress plating versus trans-syndesmotic stabilisation for posterolateral malleolus fractures: outcomes with early weight-bearing.

Abstract

Purpose: Posterolateral posterior malleolar fractures are commonly associated with syndesmotic instability, yet the optimal fixation strategy remains unclear. This study compared postoperative complications following direct posterior buttress plating and indirect trans-syndesmotic stabilisation, and evaluated differences in postoperative weight-bearing.

Methods: A retrospective review of a prospectively maintained trauma database at a Level 1 major trauma centre (2012-2021) was performed. Patients with posterior malleolar fractures treated with buttress plating or syndesmotic stabilisation were included. Radiographs, with computed tomography where available, were used to assess fragment size. Postoperative complications and factors associated with early weight-bearing were analysed using multivariable logistic regression.

Results: Of 1283 ankle fractures, 445 (34.6%) involved the posterior malleolus; 382 met the inclusion criteria. Buttress plating was performed in 184 patients and syndesmotic stabilisation in 111. Mean follow-up was 10 and 8.8 months. Overall complication rates were similar, with no significant differences in infection, loss of reduction, revision surgery, or arthrodesis. Metalwork removal was more frequent following syndesmotic stabilisation (37.8% vs 10.3%, p < 0.001). Early weight-bearing was more common after buttress plating (41.8% vs 22.9%) and remained independently associated after adjustment (OR 2.81, 95% CI 1.12-11.46).

Conclusion: Both techniques demonstrate comparable safety profiles. However, direct fixation was associated with a greater likelihood of early postoperative weight-bearing. As postoperative rehabilitation protocols were not standardised, this finding should be interpreted cautiously and may reflect surgeon preference in addition to fixation strategy. In the presence of a syndesmotic injury associated with a posterior malleolar fragment of sufficient size to permit fixation, direct fixation of the posterior malleolar fragment should be considered, as it may restore stability and facilitate rehabilitation. Further prospective studies with standardised rehabilitation protocols and longer-term follow-up are required.