Surgical treatment of swan-neck deformity in hemiplegic cerebral palsy

Purpose: Previously described surgical treatments for dynamic swan-neck deformity in cerebral palsy are technically difficult and time consuming. Typically only a few fingers could be addressed at one sitting, and postoperative swelling and stiffness were often incurred. An easy procedure of central slip tenotomy is described that allows for multiple fingers to be addressed, with minimal postoperative morbidity. Methods: Fifteen patients (33 fingers) with hemiplegic cerebral palsy and dynamic swan-neck deformities of their fingers were treated. Only swan-neck deformities of greater than 20 degrees were considered for treatment. Pre- and postoperative measurements of swan-neck deformity were recorded. A central slip tenotomy was performed through a transverse incision proximal to the proximal interphalangeal joint. The joint was pinned in 10 degrees of flexion for 4 weeks, and then active extension was allowed to 100 short of full extension and blocked with an oval-8 splint. Average patient age was 16 years (range 5-44 years). All patients had concurrent procedures performed on the extremity. Average follow-up evaluation was 23 months (+/- 12 months). Results: Improvement in dynamic swan-neck deformity averaged 32 degrees. Preoperative swan-neck deformity averaged 38 degrees and postoperative swan-neck deformity averaged 6 degrees. No swan-neck deformity was worse than its preoperative state, and no patient developed boutonniere deformity. No patient lost active or passive flexion after the procedure. All patients would repeat the procedure. Conclusion: Central slip tenotomy is a reliable treatment for dynamic swan-neck deformity in cerebral palsy in patients without dynamic metacarpophalangeal flexion deformity. Because of the simplicity of the procedure, it can easily be added to the treatment of the entire upper extremity in cerebral palsy.