This study aims to compare the outcomes of two surgical techniques for Achilles tendon lengthening in ambulatory children with cerebral palsy (CP): the percutaneous needle technique and the traditional open Z-lengthening technique. The primary objective is to evaluate the effectiveness of these techniques in improving ankle dorsiflexion and gait function one year postoperatively. Secondary objectives include assessing postoperative complications, re-rupture rates, and patient satisfaction. The study is designed as a retrospective, matched-pair cohort study, utilizing data from clinical records, 3D gait analysis (3DGA), and structured telephone interviews.

Inclusion Criteria:

• Ambulatory children with spastic cerebral palsy (unilateral or bilateral).
• Indication for Achilles tendon lengthening confirmed by 3D gait analysis.
• Underwent unilateral either percutaneous needle technique or open Z-lengthening between 2015 and 2022.
• Availability of preoperative and one-year postoperative 3D gait analysis data.
• Informed consent obtained.

Exclusion Criteria:

• Multilevel surgical interventions.
• Previous foot surgeries that alter foot anatomy.
• Non-compliance with rehabilitation protocols or orthotic use.
• Botulinum toxin-A injections in the triceps surae within six months pre- or post-surgery.
• Incomplete or inadequate 3D gait analysis data.
• Lack of informed consent.

This retrospective, matched-pair cohort study investigates the outcomes of percutaneous needle technique versus open Z-lengthening for Achilles tendon lengthening in children with spastic cerebral palsy. The study will assess changes in ankle dorsiflexion, gait function, and the incidence of postoperative complications. Data will be gathered from 3D gait analysis reports, clinical records, and structured telephone interviews. The primary outcome is the degree of passive ankle dorsiflexion one year postoperatively. Secondary outcomes include active ankle dorsiflexion, adverse events and re-rupture rates. The results aim to inform clinical decision-making and optimize surgical management for children with CP-related gait impairments.