Related Experiment Video
Updated: May 3, 2026

An Anatomical Study of Nerves at Risk During Minimally Invasive Hallux Valgus Surgery
Published on: February 17, 2018
The Learning Curve of Reverdin-Isham and Akin Percutaneous Osteotomies for Hallux Valgus Correction: A Bayesian
Carlo Biz1,2, Elisa Belluzzi1,2,3, Alberto Crimì1
1Orthopedics and Orthopedic Oncology, Department of Surgery, Oncology and Gastroenterology DiSCOG, University-Hospital of Padova, Via Giustiniani 3, 35128 Padova, Italy.
Abstract:
Background/Objectives: Assessing the learning curve is essential for surgical techniques that require precision and technical adaptation. Although modified Reverdin-Isham and Akin percutaneous osteotomies (RIAOs) are well-established procedures for the treatment of hallux valgus (HV), their percutaneous nature and specific technical demands justify the evaluation of the learning curve. Therefore, this study aimed to assess the learning curve of RIAOs for the HV correction, using for the first time a Bayesian approach. Methods: Modified RIAOs were applied to treat mild-to-moderate HV in patients who were prospectively enrolled. The hallux valgus angle (HVA), inter-metatarsal angle (IMA), distal metatarsal articular angle (DMAA) and tibial sesamoid position were assessed. Clinical outcomes were evaluated with the American Orthopaedic Foot & Ankle Society (AOFAS) Scale, Visual Analog Scale (VAS) and Numerical Rating Scale (NRS). Surgery and fluoroscopy times were recorded. To evaluate the learning curve, a Bayesian analysis using a change point model was performed. Results: Analysis of 142 patients revealed three distinct phases in the learning curve, with a plateau reached after 112 procedures. Over time, the mean operation duration decreased from 55 to 27 min, and fluoroscopy time decreased from 60 to 28 s. Conclusions: A flexible change point model was used to model a learning curve, guaranteeing a robust interpretation of the data. The correction of the HV angles showed similar results in the three phases of the curve, demonstrating that the surgeon achieved positive results from the beginning of the surgery.

