Hallux valgus associated to osteoarthritis: Clinical-radiological outcomes of modified SERI technique at mid- to long-term follow-up. A retrospective analysis

Introduction: Treatment of hallux valgus deformity associated with mild or moderate osteoarthritis (OA) is still a topic of debate. In the literature, there are few studies concerning the management of patients affected by this condition. This study aims to report the experience at mid- to long-term results of an original joint-preserving surgical technique. Materials and Methods: Patients affected by mild to moderate hallux valgus deformity and associated to grade 1–2 OA and treated with modified Simple-Effective-Rapid-Inexpensive (SERI) technique from 2008 to 2018 were selected. Inclusion criteria were mild or moderate hallux valgus angle (HVA) <40° and an intermetatarsal angle (IMA) <20° and associated grade 1–2 OA of the first metatarso-phalangeal joint (MTPJ). Results: 128 feet in 120 consecutive patients, undergone modified SERI procedure, have been retrospectively reviewed at a mean follow-up of 5.1 ± 3.8 years (range 2–11). American Orthopaedics Foot Ankle Society (AOFAS) score that was significantly improved from 44.2 ± 13.2 to 88.2 ± 9.6. Pre-operative average HVA and IMA values decreased respectively from 31.6° ± 3.9° to 9.1° ± 4.4° and from 16.2° ± 3.8° to 7.2° ± 3.1°. The average distal metatarsal articular angle (DMAA) value improved from 28.2° ± 6.5° to 7.1° ± 6°. OA of the first MTPJ highlighted a grade 1 in 46 feet and a grade 2 in 82 feet pre-operatively and a grade 0 in 30 feet, grade 1 in 82 feet, and grade 2 in 16 feet at the final follow-up. Conclusions: The modifications to the SERI technique could extend the indications to patients affected by hallux valgus with mild to moderate OA. The wider case series and the longer follow-up of this study make us believe this technique is very useful for improving the quality of life in these patients. Level of evidence: IV.