Spinal surgery in patients with Parkinson's disease: Construct failure and progressive deformity

Study Design. Retrospective case series review of patients with Parkinson's disease undergoing elective spine surgery at a single tertiary referral center. Objectives. To assess the rate of complications of spine surgery in the population with Parkinson's disease and characterize the causes of failure and special needs of this unique population. Summary of Background Data. Patients with Parkinson's disease experience a combination of poor bone quality and a severe neuromuscular disorder. There is little information in the literature about outcomes of spine surgery in this population. Preliminary review suggests that these patients have a high rate of instrument-related complications that has not been reported previously. Methods. A computerized search using diagnostic and procedural codes identified 14 patients with Parkinson's disease who underwent spine surgery from January 1993 through December 2000. Their charts and radiographs were reviewed, and those not examined within twelve months were invited for follow-up review. The remaining patients were being followed on a regular basis by their spine surgeon, the Movement Disorders Clinic, or both and were seen and examined during their routine follow-up observation. Indications and Extent of Index Surgery Varied. Complications, revisions, and radiographic evidence of loosening were assessed. Causes of failure were sought with respect to surgical and clinical factors. All patients underwent surgical care by a fellowship-trained spine surgeon. Results. The mean follow-up period from index procedure was 66.8 months; the median follow-up period was 38 months. Of 14 patients, 12 (86%) required additional surgery, undergoing a total of 31 reoperations. Eleven patients (79%) underwent 22 additional procedures at the same or adjacent level for instability, including four patients (29%) who had hardware failure or pullout, necessitating 10 reoperations. The one other patient who required additional surgery had a successful index procedure but underwent another operation to address instability at a remote spinal segment. Of five patients whose index procedure involved only one spinal level, three (60%) required additional procedures, all at that level. Two patients (14%) developed wound infections during the course of treatment but not as the cause of initial treatment failure. The primary mechanisms of failure were relentless kyphosis or segmental instability at the operated-on or adjacent levels. Conclusion. Patients with Parkinson's disease undergoing spine surgery in a single tertiary referral center had a very high reoperation rate associated with technical complications. Patients should be appropriately counseled regarding the increased risk of operative complications and closely followed for incipient failure.