Clinical and Radiological Outcomes of Modified Lapidus Procedures Using 2 Compression Cannulated Screws in Hallux Valgus Deformity

Abstract

Category: Midfoot/Forefoot; Bunion Introduction/Purpose: Hallux valgus is common disease. Surgical correction is usually required because, conservative treatment can not correct deformity and lacks evidence for prevention of progression of deformity. Among the various methods for the correction of hallux valgus deformity, the modified Lapidus procedure is known to be performed in less than 10%. The purpose of this study is to investigate the clinical and radiological outcomes of patients who underwent the modified Lapidus method. Methods: From January 2010 to December 2019, 34 cases of patients who underwent the modified Lapidus procedure and followed up for at least 6 months were included in the study. For clinical evaluation, VAS score, AOFAS score, and patient satisfaction (very satisfied, satisfied, dissatisfied, very dissatisfied) were used. For radiological evaluation, hallux angle and 1-2 metatarsal angle on anterior and posterior foot x-ray of the weight-bearing were used. Furthermore, rate of bone union and the period until bone union were also evaluated. Results: The mean follow-up period was 21.0 (6~108) months. The indications for surgery were: Severe hallux valgus in 30 cases, metatarsus adductus in 17 cases, recurrent hallux valgus in 4 cases, and hypermobility of the first tarso-metatarsal joint in 10 cases. In terms of VAS score, between pre-operation and the last follow-up was significantly improved from 5.8+-2.1 to 1.1+-1.4 (p<0.05), and the AOFAS score from 52.8+-15.0 to 92.3+-9.8 (p<0.05). In terms of patient satisfaction, 33 patients (97.1%) showed overall satisfaction (very satisfied and satisfied). Complications were nonunion in 3 cases (8.8%), incomplete union in 1 case, delayed union in 1 case, and hallux varus in 1 case. There was no additional surgery for these complications. At preoperative and last follow-up, the hallux angle improved from 46.0°+-10.7° to 5.9°+-11.7°, and the 1-2 IMA improved from 18.2°+-5.1° to 5.5°+-4.5°. In the cases excluding complications, the average period to bone union was 3.9(3-8) months. Conclusion: In our study, the modified Lapidus method using 2 compression cannulated screws was showed satisfactory clinical, radiological outcomes and relatively satisfactory bone union (91.2%) in a short follow-up. The modified Lapidus method using 2 compression cannulated screws is a considerable option for severe hallux valgus deformity.