REPEAT SURGICAL INTERVENTIONS FOLLOWING "DEFINITIVE" INSTRUMENTATION AND FUSION FOR IDIOPATHIC SCOLIOSIS

B.S. Richards, MD
Texas Scottish Rite Hospital for Children, Dallas, TX, USA

PURPOSE:
With the exception of very young patients, spinal instrumentation and fusion should represent the definitive and final intervention needed in the management of idiopathic scoliosis. Because this is not always the case, this study tries to 1) determine the percentage of operations performed for idiopathic scoliosis that represents unplanned additional surgery and 2) what is responsible for these necessary reoperations.

METHODS:
As determined on a review of surgical records at a single institution from Jan 1988 through Dec 1999, primary spinal instrumentation (anterior or posterior) with fusion was performed on 793 idiopathic scoliosis patients 8–17 years old. Most were teenagers at the time of primary surgery. During the same twelve year interval, all patients 8–17 years old were identified who required one or more reoperations related to their idiopathic scoliosis. The reasons for, and the number of, reoperations were examined. For those with infections, repeated I/Ds over the course of 2–6 days were considered as one further intervention (reoperation).

RESULTS:
130 reoperations were performed on 106 patients between 1988 and 1999. (11/106 patients underwent their primary spinal instrumentation and fusion prior to 1988). Reoperations accounted for 14 percent (130/923) of the total number of operations for idiopathic scoliosis that included instrumentation. 88 pts had one reoperation, 14 had two reoperations (>3 months apart if related to infection), 2 had three reoperations, and 2 had four reoperations. Of the 130 reoperations, 38 (29%) were because of infection (acute 14, delayed 24); 32 (25%) represented hardware removal because of pain (12 partial, 20 complete); 41 (32%) included reinstrumentation +/– osteotomy because of pseudarthrosis, curve progression, or fracture; 9 (7%) were for revision of loosened hardware; 3 (2%) were for elective thoracoplasties; and 6 (5%) were for minor procedures (repeated wound closure, thoracic duct ligation, chest tube reinsertions, and scar revisions). For those eighteen patients who required multiple reoperations, most of the procedures involved reinstrumentation for persistent pseudarthroses. Four of the 18 patients developed an infection following hardware revision or pseudarthrosis reinstrumentation.

CONCLUSIONS:
Reoperations following spinal instrumentation and fusion were found to represent 14% of idiopathic scoliosis surgical cases done over a 12 year period. Most were necessary because of painful hardware, dislodged instrumentation, or pseudarthroses. The presence of significant infection accounted for nearly one–third of reoperations. Patients undergoing spinal instrumentation and fusion for idiopathic scoliosis should be advised of these potential problems which may require further surgery.