Introduction: Stability of isolated Weber B ankle fractures can be difficult to determine. Using weight-bearing radiographs, a reliable method to determine the stability of isolated Weber B ankle fractures is described.
Methods: A retrospective review of prospectively gathered data was performed. Weber B ankle fractures were defined as stable when having a medial clear space (MCS) of <7 mm on initial gravity stress radiographs and a normal mortise relationship on weight-bearing radiographs. Fifty-one patients meeting these criteria were treated nonsurgically with protected weight bearing and serial radiography for 1 year.
Results: Average functional score results were: American Orthopaedic Foot and Ankle Society Hindfoot, 93.2; Foot and Ankle Ability Measure for Activities of Daily Living, 93.2; Olerud-Molander Ankle Score, 91.0; and visual analog scale pain score, 0.57. Despite a mean gravity stress MCS of 4.42 mm, no patient demonstrated subsequent MCS widening. Mean MCS on 1-year follow-up weight-bearing radiographs was 2.64 mm.
Conclusion: Weight-bearing ankle radiographs are predictive of stability in isolated Weber B ankle fractures. Gravity stress radiographs using traditional measurement criteria may overestimate instability in these injuries. Nonsurgical treatment with protected weight bearing shows good early outcomes.
Level of evidence: IV.