Radiographic and Patient-Reported Outcomes of a Low-Cost Modified Lapidus Bunion Correction Technique

BACKGROUND: The modified Lapidus (ML) is a powerful procedure for correction of hallux valgus (HV) with emerging techniques. Studies considering patient-reported outcomes, radiographic measures, complications, and implant costs are currently limited. METHODS: Retrospective cohort with prospectively collected Patient Reported Outcome Information System Physical Function (PROMIS-PF) Computerized Adaptive Test (CAT) scores, radiographic parameters (intermetatarsal angle, IMA; hallux valgus angle, HVA; and tibial sesamoid position, TSP), complications, and total operative time and implant costs were reviewed from 2014 to 2019. RESULTS: Seventy-three feet (68 patients) underwent bunion correction by ML with lag-screw fixation. Median age was 55.8 years (IQR 45.6, 53.9), 4 of 73 (5.5%) were male, 11 of 73 (15.1%) were smokers, and 15 of 73 (20.6%) were diabetic (median HbA1c 6.4% [IQR 6.0, 7.4], none insulin dependent, 5 of 15 with neuropathy). Complications included 6 of 73 (8.2%) wound issues resolved with topical or oral treatment, 9 of 73 (12.3%) painful or broken hardware requiring hardware removal. Two of 73 (2.7%) had persistent pain despite union. One of 73 (1.4%) was overcorrected and required first MTP arthrodesis. Of 3 nonunions (2.7%), 1 resolved with corrected hypothyroidism, 1 was asymptomatic and required no treatment, 1 had a hallux valgus recurrence and sought revision surgery elsewhere. Preoperative radiographic angles were HVA 35 degrees, IMA 14 degrees which improved at final postoperative follow up to HVA 10 degrees, IMA 6 degrees. Tibial sesamoid position improved from 6.05 ± 1.00 to 2.22 ± 1.38. Thirty-two patients had preoperative and 42 had 1-year postoperative outcomes. PROMIS-PF (51% collection rate) was 43 (IQR 37,52) preoperatively, 37 (31, 39) at 6 weeks, 46 (42, 51) at 3 months, and 49 (41, 53) at >360 days postoperatively. The drop in PROMIS-PF between preoperative and 6 weeks and the rise from 6 weeks to 3 months were statistically significant. Pre- and postoperative PROMIS-PF scores were not significantly different. Implant cost averaged US$146. DISCUSSION/CONCLUSION: We report low complication rates and costs with high patient postoperative functional and radiographic outcomes. PROMIS-PF decreased acutely postoperatively but recovered and maintained high levels by 3 months postoperatively. LEVEL OF EVIDENCE: Level IV, case series.