Late knee problems in myelomeningocele.

This study was undertaken to assess the incidence and etiology of knee problems in a long-term follow-up of myelomeningocele patients. Of the 72 community ambulators reviewed, 17 (24%) had significant knee symptoms. A specific gait pattern was identified in symptomatic patients with low lumbar lesions, which may be explained on the basis of hip abductor and calf muscle weakness. These patients have a characteristic gait, which places abnormal stress on the knee, leading to medial and anteromedial rotary instability and eventual degenerative change. It is likely that disability resulting from knee symptoms will be the factor precluding independent ambulation in the patients reviewed in this study.