We investigated retrospectively 132 cases of open wedge high tibial osteotomy using an external fixation device, concentrating on the rate of neurological complications. One group of patients underwent surgery according to the conventional technique (n = 89). The rate of transient neurological complications was 15.7%; 7 months after surgery the rate of persistent deficits was 12.4%. For the second group (n = 43) a modified surgical technique was used that lowered the complication rate significantly (transient deficits 14%, persistent deficits 4.7%). In the modified technique the osteotomy is not performed in the conventional way using an oscillating saw but through consecutive drill holes of increasing diameter followed by osteoclasis. The lower complication rate in the second group is mainly due to the less extensive approach that leads to a smaller number of postoperative tibialis anterior syndromes (type B lesion). No differences were found with type C lesions (extension deficit of D1). No complete peroneal nerve palsy (type A) occurred in either group. We conclude that the reduction of neurological complications in group 2 is related to the less extensive approach of the proposed technique.

The purpose of this study is to evaluate the influence of halo-gravity-traction on paralytic scoliosis in various neurologic diseases. Between 1980 and 1993 preoperative halo-gravity-traction was applied in 32 patients with paralytic scoliosis (23 patients with myelomeningocele, 6 patients with poliomyelitis, 3 patients with cerebral palsy). In the myelomeningocele group the average curvature before treatment was 97.8 degrees, after surgery 45.1 degrees; which is an improvement of 53.9%. Halo-gravity-traction accounted for 12.8% improvement. In the poliomyelitis group the average curvature before treatment was 104.3 degrees, after surgery 58.0 degrees; which is an improvement of 44.4%. Halo-gravity-traction accounted for 16.9% improvement. In the cerebral palsy group the average curvature before treatment was 75.0 degrees, after surgery 39.0 degrees; which is an improvement of 48.0%. Halo-gravity-traction accounted for -2.7% improvement. If there is an effect the question remains, whether this will have consequences for the surgical outcome. The comparison between good and bad responders with the surgical result shows, that this result is independent of the halo-gravity-traction. From this results we draw the conclusion, that preoperative halo-gravity-traction can not be recommended in paralytic scoliosis.

High tibial wedge osteotomies are often followed by transient neurological complications. From a retrospective study of 132 patients it appears that the incidence of this troublesome complication can be reduced after osteotomy with external fixation by using a technique of making consecutive drill holes of increasing diameter followed by osteoclasis. This reduction of neurological complications was most marked when a less extensive surgical approach was used.