Natural history of knee contractures in myelomeningocele.

The natural history of knee contracture was determined in a prospective study of 850 myelomeningocele (MM) patients, ranging in age from neonate to 23 years, excluding patients after knee surgery. Fixed flexion contracture of 10 degrees at birth decreased by age 9 months but increased thereafter if the patient's MM level was higher than L3. In the thoracic/L1-L3 level patients, the mean fixed flexion contracture was 18 degrees with and 17 degrees without knee flexor spasticity. Range of knee flexion remained at 126 degrees until age 3 years, and decreased thereafter if the patient's MM was higher that L3. This study demonstrates that muscle imbalance and spasticity play a minimal role in development of knee contracture.