The risk of talar shift in nonoperatively treated Weber B lateral malleolar fractures with suspected medial injury: a clinical and radiological outcomes analysis

M. Siddiqui, K. Brogan, L. Rymaszewski, S. Atiya, C. Senthil Kumar

Introduction: Isolated Weber B lateral malleolus fractures heal uneventfully, but concern that late subluxation may occur due to unrecognised medial ligament tearing, despite an intact mortice on initial radiographs, often results in overtreatment. The aim of this study was to determine the incidence of late talar shift with nonoperative management in a cohort of patients with no initial talar shift, and also record functional outcomes at 16-28 months following injury.

Methods: This was a retrospective review of 129 patients with Weber B lateral malleolar fractures initially referred to the fracture clinic between October 2011 and October 2012. Eight had obvious talar shift and therefore underwent surgery, with the remaining 121 treated in plaster (n=41), a Velcro boot (n=70) or bandage (n=10). No stress x-rays or MRI scans were performed. Weight-bearing was permitted as pain allowed. Radiographs taken on discharge from the clinic were reviewed to assess talar shift. Functional outcomes assessment was carried out using Manchester Oxford Foot Questionnaire and Olerud-Molander score.

Results: None of the 121 patients had talar shift initially; 21 patients where medial injury was strongly suspected were closely followed and had check x-rays more often (average 2.9 appointments per patient) than the other groups. No patients had talar shift in any of the subsequent x-rays and therefore none underwent delayed internal fixation. The mean MOXFQ and Olerud-Molander scores were 27 and 78 respectively in 57 patients and the functional outcomes were not influenced by type of immobilisation or suspected medial injury.

Conclusion: Our observation is that the risk of late talar shift is likely to be low in patients where initial x-rays had showed no talar displacement. It may be unnecessary to perform additional tests/imaging to establish the integrity of the medial ligament as satisfactory functional results are routinely observed.