Surgical release of tethered spinal cord: survivorship analysis and orthopedic outcome.

Between January 1988 and February 1995, 133 tethered spinal cord-release procedures in 88 consecutive patients were performed at our institution 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 palsy (three), and others (seven). Survivorship data were calculated for the initial and first-revision tethered cord release. There was a 50% revision rate by 5 years after initial tethered-cord release and a 57% revision rate by 2 years after a second release. Thirty-six patients were excluded for having <2 years of clinical follow-up, leaving 97 spinal cord releases in 52 patients available for outcome analysis. At a mean follow-up of 4.4 years (range, 2-11.3), 58% of patients required one or more orthopedic procedures after tethered-cord release. The average number of orthopedic procedures per year before release (0.28/year) 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 dysraphism. In addition, the need for orthopedic procedures after tethered spinal-cord release frequently persists.