Screwless minimally invasive triplane osteotomy for the surgical treatment of hallux valgus in patients aged 60 years and older: a prospective observational clinical study.

Introduction: Minimally invasive surgery (MIS) for hallux valgus gained increasing recognition with comparable clinical and radiological outcomes to traditional open surgery. However, there is lack of evidence for safety and efficacy of MIS in the elderly. The aim of this study is to evaluate the surgical and functional outcomes of hallux valgus correction in elderly using screwless MIS technique according to the "triplane osteotomy".

Materials and methods: From May 2019 until September 2020 a prospective observational study was set up with patients ≥60 years with symptomatic hallux valgus with an angle (HVA) above 25 degrees or intermetatarsal angle (IMA) above 14 degrees with failure of conservative treatment for at least six months. A single surgeon used a "triplane osteotomy" for the metatarsal, an Akin osteotomy and lateral soft tissue release. A temporary K-wire was used and removed after three weeks. Patients were assessed six weeks, three months and one year postoperatively. Clinical and functional assessment were obtained by the visual analogue scale (VAS) score, American Orthopaedic Foot and Ankle Society (AOFAS) and the Foot Function Index (FFI). Radiographical assessment included the HVA, IMA and DMAA.

Results: 37 patients with a mean of 66.05 ± 5.53 years were included. Preoperatively the VAS reduced from 5.19 ± 2.55 to 0.47 ± 0.99, the FFI from 54.00 ± 13.71 to 26.22 ± 7.81, the AOFAS improved from 46.11 ± 13.41 to 83.46 ± 15.91, the HVA from 34.43 ± 8.38 degrees to 7.31 ± 5.55 degrees, the IMA from 13.58 ± 2.55 degrees to 7.48 ± 2.99 degrees and the DMAA from 11.92 ± 5.43 degrees to 7.52 ± 5.19 degrees at one year follow-up. Except for the FFI at six weeks, all functional outcome scores improved significantly compared to preoperatively (P <.001).

Conclusions: Screwless minimally invasive triplane osteotomy provided significant clinical, functional and radiological improvement for the treatment of hallux valgus in patients aged 60 years and older.

Level of evidence: Level IV, a prospective observational cohort study.