Improvement of popliteal angle with semitendinosus or gastrocnemius tenotomies in children with cerebral palsy

Objective: The aim of this study was to determine the efficacy of semitendinosus and gastrocnemius tenotomies on popliteal angle presenting knee flexion spasticity in children with cerebral palsy (CP). Methods: The study included 44 patients (25 males, 19 females; mean age: 8.1 years, range: 4 to 14 years) with spastic CP who underwent surgery for knee flexion spasticity. A total of 78 semitendinosus tenotomies and 28 associated gastrocnemius tenotomies were performed. Popliteal angle was measured under general anesthesia before and after surgery. Patients were divided into groups according to age (younger and older than 7 years), severity of deformity and type of CP. Results: Mean popliteal angles decreased by 14.3° (30.1%) following semitendinosus tenotomy and by 6.1° (12%) following gastrocnemius tenotomy (p=0.0001). The change in popliteal angle was not statistically significant according to age, severity of flexion spasticity, and type of CP palsy. There was a significant difference following gastrocnemius tenotomy between groups with a popliteal angle of greater or lesser than 50° (p=0.0001). Conclusion: Semitendinosus and gastrocnemius tenotomies improved popliteal angle by 30.1% and 12%, respectively. Age, preoperative popliteal angle or anatomical disease classification did not a significantly affect popliteal angle.