SURGICAL RELEASE OF TETHERED SPINAL-CORD - SURVIVORSHIP ANALYSIS AND ORTHOPEDIC OUTCOME

Between January 1988 and February 1995, 133 tethered spinal cord-relea se procedures in 88 consecutive patients were performed at our institu tion and were used to determine survivorship data for surgical release of tethered spinal cord. The diagnoses included spinal dysraphism (67 ), achondroplasia (nine), isolated tethered cord (nine), cerebral pals y (three), and others (seven). Survivorship data were calculated for t he initial and first-revision tethered cord release. There was a 50% r evision rate by 5 years after initial tethered-cord release and a 57% revision rate by 2 years after a second release. Thirty-six patients w ere excluded for having <2 years of clinical follow-up, leaving 97 spi nal cord releases in 52 patients available for outcome analysis. At a mean follow-up of 4.4 years (range, 2-11.3), 588 of patients required one or more orthopedic procedures after tethered-cord release. The ave rage number of orthopedic procedures per year before release (0.28/yea r) was found to increase after initial release (0.39/year; p < 0.05). These data demonstrate the frequent need for operative revision after index tethered-cord release, especially in children with spinal dysrap hism. In addition, the need for orthopedic procedures after tethered s pinal-cord release frequently persists.