Clinical and Ultrasonographic Outcomes of Percutaneous Achilles Tenotomy Using an 18-Gauge Needle in Idiopathic Clubfoot: A Prospective Study

Introduction: Percutaneous Achilles tenotomy is a critical step in the Ponseti method for correcting residual equinus deformity in idiopathic clubfoot. Needle tenotomy has emerged as a minimally invasive alternative to conventional scalpel-based tenotomy, offering potential advantages in safety, procedural cost, and ease of performance. Prospective combined clinical and ultrasonographic evidence evaluating this technique from Indian centers remains limited. Objective: The aim of the study was to evaluate the clinical and ultrasonographic outcomes of percutaneous Achilles tenotomy using an 18-gauge needle in children with idiopathic clubfoot managed by the Ponseti method. Materials and Methods: This prospective study included 45 children (76 ft) with idiopathic congenital talipes equinovarus. Serial Ponseti casting was performed until residual equinus was the only deformity remaining, after which percutaneous Achilles tenotomy was performed using an 18-gauge needle under general anesthesia. Patients were evaluated preoperatively and at 3 weeks, 2 months, 6 months, and 1 year using the Pirani score, passive dorsiflexion angle at the ankle, and foot bimalleolar angle on podogram. Ultrasonography was performed at the 3-week follow-up to assess tendoachilles healing. Results: The mean age at tenotomy was 7.3 ± 2.76 months, with male predominance (71.11%) and bilateral involvement in 68.89% of cases. On ultrasonography at 3 weeks, 14 of 76 ft (18.42%) showed a tendon defect, and 9 of 76 ft (11.84%) showed peri-tendinous collections; both abnormalities resolved by the 2-month follow-up. The mean Pirani score improved significantly from 2.11 ± 0.40 preoperatively to 0 at 1 year (t = 42.93, df = 66, P < 0.05). The mean passive dorsiflexion angle improved from 128.74° ± 12.04° to 76.21° ± 2.15° (mean difference 52.53° ± 11.57°; t = 36.90, df = 65, P < 0.05), and the mean foot bimalleolar angle improved from 70.09° ± 2.70° to 81.74° ± 1.58° (t = -48.96, df = 65, P < 0.05). Forty patients (88.90%) maintained correction without additional surgery; four patients (8.88%) required posteromedial soft-tissue release, and one patient (2.22%) required unilateral tendoachilles lengthening. Conclusion: Percutaneous Achilles tenotomy using an 18-gauge needle is a safe, effective, and minimally invasive technique for correcting residual equinus in idiopathic clubfoot. The procedure yields favorable clinical correction, satisfactory ultrasonographic tendon healing, and a low rate of secondary surgical intervention.