Factors Influencing the Treatment Effect of Superelastic Wire Orthonyxia for Nail Plate Deformity.

BACKGROUND: Orthonyxia is an effective, noninvasive treatment for transverse nail curvature deformity. OBJECTIVE: To discover the factors influencing treatment results of superelastic wire orthonyxia (SEWO). MATERIAL AND METHODS: A retrospective study was conducted using clinical records of patients treated with SEWO. A multiple linear regression model was used to explain the correlation between correction pace (% per week) and the other collected variables (patient age, sex, position of treated toe, wire diameter [WD, mm], wire residence time [WRT, weeks], nail plate thickness [PT, mm], baseline nail curvature index [NCI], number of previous treatments, and the correction pace of previous treatments [CPT, % per week]). A logistic regression model was used to identify risk factors for adverse effects. RESULTS: A total of 475 cases were collected from 197 patients. The correction pace was positively related to baseline NCI, WD, and correction pace in previous treatment. Also, it was negatively related to WRT and nail PT. No clinical factor was correlated with the occurrence of side effects. CONCLUSION: The correction pace of SEWO is affected by the baseline NCI, the diameter of the wire, nail PT, the CPT, and the WRT.