Kyphotic deformity in patients who have a myelomeningocele. Operative treatment and long-term follow-up

The results of resection of the lordotic segment cephalad to the apical vertebra of a kyphotic deformity in thirty-nine patients who had had a myelomeningocele were reviewed retrospectively. The operations were performed between 1973 and 1984, when the patients were an average of six years and ten months old (range, one year and five months to twenty years old). The average duration of follow-up was eleven years and one month (range, five years and one month to seventeen years and four months). The average preoperative kyphosis was 111 degrees (range, 77 to 151 degrees) and the average postoperative kyphosis was 40 degrees (range, 2 to 88 degrees). The preoperative deformity was reduced an average of 64 per cent (range, 0 to 98 per cent). At the latest follow-up evaluation, the average kyphosis was 62 degrees (range, -25 to 100 degrees). The measurements were obtained from lateral radiographs that were made with the patient sitting preoperatively, immediately postoperatively, at one year, and yearly until the time of the latest follow-up evaluation. At the most recent examination, thirty-four patients had a partial loss of correction, with twenty-five of them having maintained at least 50 per cent of the correction. The five remaining patients had an improvement in the alignment by an average of 26 degrees. Only two patients had an increase in kyphosis compared with the preoperative deformity. Thirty-seven patients had an average increase of 3.2 centimeters (range, 0.2 to 8.2 centimeters) in the height of the lumbar spine; the two remaining patients, who had a decrease in height, had operative intervention after reaching skeletal maturity.