Outcomes of Deltoid Ligament Repair in Surgically Treated Weber C Fibula Fractures with Deltoid Ligament Injury. A Retrospective Comparative Radiographic and Functional Outcomes Study

Category: Ankle; Trauma Introduction/Purpose: The indications of deltoid ligament repair in ankle injuries with widened medial clear space in the absence of medial malleolus fracture remain controversial. Many authors reported no difference in long-term functional outcomes, while others reported persistent medial clear space widening and higher malreduction when deltoid ligaments went without repair. This malreduction can lead to chronic ankle instability and pain. Talar shift as little as 1mm is reported to lead to a 49% increase in ankle joint pressure, a detrimental factor for developing post-traumatic ankle arthritis. The purpose of this study was to compare deltoid ligament repair to no repair in a homogenous group of surgically treated isolated Weber C fibula fractures exclusively. Methods: A retrospective chart review of prospectively collected data was carried out to identify consecutive surgically treated Weber C lateral malleolus fractures and syndesmosis stabilization with associated deltoid ligament injury between February 2013-December 2023. Associated posterior/medial malleolus fractures other than avulsions, Weber A/B fractures, fibula fixation constructs besides plate and screws, Charcot neuropathy, pes planovalgus with incompetent deltoid ligament, and revisions were excluded. Those meeting inclusion criteria were split into two groups: deltoid ligament suture repair vs. no repair. Collected data included demographics, smoking and diabetes status, surgical procedure and patient reported outcome measures (PROMs).. Primary outcomes were oblique medial clear space (MCS) and valgus talar tilt angle (TTA) on weightbearing radiographs. All radiographs were independently reviewed by a fellowship trained foot and ankle orthopedic surgeon. Secondary outcomes were fracture union, complications, reoperations, and PROMs: Foot and Ankle Ability Measure (FAAM), Veterans-Rand 12 (VR12) General Health Survey, visual analog pain scale (VAS). Results: Seventy-nine fractures were included; 49 underwent deltoid ligament repair while 30 did not. The mean follow-up was 18.5 months. There was a statistically significant post-op improvement in most study outcomes within the groups. The valgus TTA in the repair vs no repair groups were 0.1±0.9 vs. 1.2±2.1 degrees, respectively (p=0.007). The MCS in the repair vs. no repair groups was 3.5±0.6 vs. 3.9±1.4mm, respectively (p=0.107). There were no statistically significant differences between deltoid repair and no repair groups in post-operative VR12 MCS (p=0.194), VR12 PCS (p=0.077), VAS (p=0.231), FAAM ADL (p=0.109), FAAM sport (p=0.314), or patient satisfaction (p=0.33). The union rate was 100% in the repair vs. 96% in the no repair groups (p=0.163). There were no complications related to repairing the deltoid ligament. Conclusion: Deltoid ligament repair led to a superior ankle coronal alignment in comparison to no repair. There were no complications or revisions related to the medial approach and repairing the deltoid ligament. While there were trends toward better functional outcomes with deltoid ligament repair, this did not reach statistical significance. Long term studies may be required before recommending deltoid ligament repair as the gold standard in isolated Weber C fractures. Meanwhile, we recommend valgus stressing the ankle at the end of the procedure and decide whether deltoid repair is needed on individual basis. Outcomes of deltoid repair group vs no deltoid repair group.