Radiographic Outcomes And Recurrence Following 126 Primary Lapidus Surgeries For Hallux Valgus

CATEGORY: Bunion; Midfoot/Forefoot INTRODUCTION/PURPOSE: Treatment for symptomatic hallux valgus encompasses a spectrum of surgical options to appropriately address the degree of deformity. The modified Lapidus has emerged as a powerful surgical option to address moderate to severe deformity as well as hallux valgus with 1st ray hypermobility. Unlike metatarsal osteotomies, the literature is lacking in clinical and radiographic outcomes. Previous retrospective series have reported recurrence rates less than 15%, but our experience suggested recurrence rates were higher. METHODS: After obtaining institutional board review approval, patients were identified by procedural billing codes from 2012- 2016. Only patients who underwent a primary Lapidus surgery with greater than 1 year radiographic follow-up were included. Larger midfoot fusions and flatfoot reconstructions were excluded. Charts were reviewed to identify complications and reoperations. Radiographs were reviewed and HVA, IMA, sesamoid position (0-4), and Meary’s angle measured on preoperative, 1st weigh-bearing post-operative, and final follow-up radiographs. Data was analyzed utilizing statistical analysis software (SAS v9.4). RESULTS: 114 patients were identified with 12 undergoing bilateral surgery (126 surgeries). There were 106 females and 8 males, and median age was 57.5 years at time of surgery. Median follow-up from index surgery was 2.9 years. Using HVA>=20 as cutoff for recurrence, 58 (46%) recurrences were identified, but only 15 (12%) underwent revision surgery. There were 32 total reoperations, including 8 nonunions (table 1A). Median preoperative HVA was greater in group with recurrence than group without recurrence (38 vs 30, p<0.0001, table 1B). In addition, less correction of HVA and IMA was seen in group with recurrence (ΔHVA=20 vs 22, p<0.0001; ΔIMA 6 vs 9, p<0.0001, table 1B). When there was recurrence at final follow-up, it appears corrected IMA was maintained while HVA increased (ΔIMA=2, ΔHVA=10, table 1B). We used a receiver operative curve (ROC) to define the HVA cut-off of HVA>=30 with an AUC of 0.75. That indicated that in 75% of cases, preoperative HVA>=30 predicted recurrence. We identified that HVA<30 has a reduced odds of recurrence (OR=0.165; 95% CI=0.062-0.536). Preoperative IMA and arch alignment were not associated with risk of recurrence (table 1C). CONCLUSION: As has been determined in other hallux valgus series evaluating metatarsal osteotomies, increased HVA>=30 is a risk factor for recurrence. Despite being acknowledged as a powerful operation for hallux valgus correction, the modified Lapidus still had a high rate (46%) of radiographic recurrence when used to treat severe deformity. However, only 12% underwent revision surgery in our series. This is important when counseling patients before surgery as the modified Lapidus operation does not obviate the risk of recurrence as has been previously suggested, but the lower revision rate suggests radiographic outcomes alone do not drive satisfaction. Further outcome measures are needed on this cohort to better identify surgical variables associated with maintained correction, other risk factors for recurrence, as well as patient reported outcomes.