First Metatarsal Pronation Correction After Fourth-Generation Percutaneous Transverse Osteotomy for Hallux Valgus

Tom Lewis, Lily Fletcher, Clare Watt, Robbie Ray, Cesar de Cesar Netto, Miquel Dalmau-Pastor, Peter Lam

Introduction: There is increasing interest in the role of pronation as part of the deformity correction in hallux valgus (HV) especially with the advent of WBCT and percutaneous surgical techniques. This study aimed to assess the coronal rotation of the first metatarsal before and after percutaneous distal transverse osteotomy (META) using weight-bearing computed tomography (WBCT) and to correlate these findings with clinical outcome scores. Method: A retrospective analysis of prospectively collected data from a single centre of patients who underwent WBCT both before and after percutaneous distal transverse osteotomy for hallux valgus correction. The primary outcome was change in pronation on radiographic parameters; Hallux valgus angle, intermetatarsal angle, Metatarsal pronation angle, alpha angle, sesamoid rotation angle, arthritis and sesamoid position were assessed using coronal WBCT images. Secondary outcomes included pre- and post-operative clinical outcomes, including the Manchester Oxford Foot Questionnaire (MOXFQ), EQ-5D-5L, Visual Analogue Scores (VAS) and complication rates. Results: 51 feet from 34 patients (32 Female, 2 Male, mean age 60.3±10.2 years) underwent META. Radiographic data was available for 94.4% of feet with mean follow up of 12.1±3.2 months. There was a significant improvement across all radiographic parameters including pronation correction (p<0.05). There was also a significant improvement in clinical foot function for all MOXFQ domains, EQ-5D-5L and VAS Pain outcomes (p<0.05). The complication rate was 1.9%. There was no significant correlation of post-operative outcomes with radiographic pronation parameters. Regression analysis did not identify any radiographic or clinical variables that predicted change in MOXFQ Index domain score. Conclusion: Percutaneous distal transverse osteotomy for hallux valgus deformity can significantly correct coronal plane pronation and improve patient-reported outcomes, although correction of pronation was not significantly correlated with clinical improvement."