Effectiveness of Standalone Weight-bearing Radiographs in Guiding the Management of Supination External Rotation Type Isolated Lateral Malleolar Fractures in Indian Population: A Prospective Clinical Study

Aim and objective: To assess the effectiveness of standalone weight-bearing radiographs (WBR) in guiding the management of Supination External Rotation (SER), type of isolated lateral malleolar fractures in Indian population. Materials and methods: In a prospective study involving 19 consecutive patients with SER type of isolated lateral malleolar fractures, stability of the ankle was assessed using both WBR and external rotation stress radiographs. The decision toward conservative or surgical management was made solely on the assessment of ankle stability on WBR alone. Fractures with a medial clear space of <5 mm were deemed stable and managed conservatively (full weight-bearing in cast), while unstable ones were managed surgically (with open reduction and fibular plating). Periodic follow-up was done to assess radiological union and functional outcomes using the American Orthopaedic Foot and Ankle Society (AOFAS) score. Patient’s pain score visual analogue scale (VAS) and compliance was assessed during radiographic assessment. Results: Based on WBR alone, 17/19 (89.5%) fractures were found to be stable and treated conservatively, while 2/19 (10.5%) fractures were unstable and managed surgically. The mean AOFAS score in the conservative group [92.9 ± 3.4 (excellent)] and surgical group [91.5 ± 1.5 (excellent)] were comparable at latest follow-up. Complete radiological union was seen at 8.8 ± 1.9 (range, 8–14) weeks in 82% (14/17), while delayed union (union taking place >8 weeks) was seen in three patients in the conservative group. Four patients (21%), who would have been operated had external rotation stress views been used in decision making, were managed conservatively with successful clinical outcome and excellent AOFAS scores. Patient compliance was good with WBR as compared to external rotation stress radiographs. Conclusion: Standalone WBR are feasible, and reliable in detecting injury of the deep deltoid ligament and the consequent instability of the tibiotalar joint, in Weber type B fractures. They are associated with better patient compliance. Clinical significance: Standalone WBR serve as a useful guide in decision making between conservative and surgical treatment, in SER type isolated lateral malleolar fractures.