Modified Chevron Osteotomy with Distal Soft Tissue Release for Treating Moderate to Severe Hallux Valgus Deformity: A Minimal Clinical Important Difference Values Study

OBJECTIVE: To explore whether modified Chevron osteotomy together with distal soft tissue release would correct moderate to severe HV deformity and what is the minimal clinical important difference (MCID) for objective and subjective evaluating parameters. METHODS: From March 2018 to January 2019, 40 hallux valgus patients (including moderate to severe) were enrolled in this retrospective study. The cohort included four males and 36 females. The average age at surgery was 50.95 (range 22–75) years. All patients underwent modified Chevron osteotomy together with distal soft tissue release and completed at least one follow‐up at clinic. The American Orthopaedic Foot and Ankle forefoot score (AOFAS, forefoot), Visual Analog Scale (VAS), and Foot Function Index (FFI) were all collected before and after surgery. Besides, the hallux valgus angle (HVA), 1st–2nd intermetatarsal angle (IMA) and distal metatarsal articular angle (DMAA) were measured both before surgery and at last follow‐up. All MCID values were calculated by employing distribution‐based method. RESULTS: Thirty‐seven patients (92.5%) showed satisfied result at a mean 14.3‐month follow‐up (range 13–22 month). Two patients complained about residual pain at the bunion, and overcorrection (hallux varus) occurred in one patient. Meanwhile, no patient observed nonunion. Being female, age more than 60, residual HVA deformity (>15°), and post IMA more than 9° showed no statistical relationship with the post‐operation residual pain (P > 0.05). However, high VAS score before surgery (more than 7) showed strong correlation with residual pain (P < 0.01). The subjective MCID value was 9.50 for AOFAS, 18.92 for FFI, and 1.27 for VAS, respectively. CONCLUSION: The modified Chevron osteotomy together with distal soft tissue release could achieve a satisfied result for moderate to severe HV deformity at early follow‐up. The residual pain was associated with severe pain before surgery (VAS more than 7).