Hallux valgus angle as main predictor for correction of hallux valgus

Background: It is recognized that different types of hallux valgus exist. Classification occurs with radiographic and clinical parameters. Severity of different parameters is used in algorithms to choose between different surgical procedures. Because there is no consensus about each parameter nor their cut-off point we conducted this study to analyze the influence of these variables on the postoperative hallux valgus angle. Methods: After informed consent 115 patients (136 feet) were included. Bunionectomy, osteotomy, lateralization of the distal fragment, lateral release and medial capsulorraphy were performed in all patients. Data were collected on preoperative and postoperative HVA, IMA and DMAA measurements. Forty cases were included since our findings in a previous article [1], therefore, current data concern an expanded study group with longer follow-up and were not published before. At least two-year follow-up data were evaluated with logistic regression and independent t-tests. Results: Preoperative HVA was significant for prediction of postoperative HVA in logistic regression. IMA and DMAA were not significant for prediction of postoperative HVA in logistic regression, although they were significantly increased in larger deformities. In patients with preoperative HVA of 37 degrees or more, satisfactory correction could be obtained in 65 percent. The other nine of these 26 patients developed subluxation. Conclusion: The preoperative HVA was the main radiological predictor for correction of hallux valgus, correction rate declined from preoperative HVA of 37. IMA and DMAA did have a minor role in patients with preoperative HVA lower than 37 degrees, however, likely contributed to preoperative HVA of 37 degrees or more.