Abstract
Patients with spastic diplegia who walk with a crouched posture often suffer from anterior knee pain, thought to be due to cephalad displacement of the patella. Ambulation with flexed knees elongates the patellar tendon, which leads to development of patella alta. Our study of 57 patients with spastic diplegia aimed to determine the severity of patella alta and to investigate its correlation with spasticity and muscle imbalance at the level of the knee.
The ages of the 31 male and 26 female patients ranged from 3 months to 16 years. They were divided into two groups, one with spasticity of the hamstrings and the other with combined spasticity of the quadriceps and hamstrings. Clinical evaluation documented anterior knee pain, walking capacity, fixed deformities, hamstrings and rectus femoris shortening, and patellar mobility. Lateral radiographs were taken to measure the length of the patella and the patellar tendon. We used the method described by Insall and Salvati to calculate the patellar ratio. The clinical findings were examined for correlations with the severity of patella alta.
We found that the group of patients with quadriceps and hamstring spasticity had a higher rate of patellar displacement but less frequent anterior knee pain than the group of patients with hamstring spasticity alone.
The abstracts were edited by Prof. M.B.E. Sweet. Correspondence should be addressed to him at the Department of Orthopaedic Surgery, Medical School, University of the Witwatersrand, 7 York Road, Parktown, 2193 South Africa
