Complication Rates for Combined Anterior-Posterior Adult Deformity Surgery

Purpose: To evaluate complication rates for anterior-posterior adult deformity surgery and to determine whether or not patients undergoing revision surgery were more likely to experience complications than those undergoing primary surgery.

Methods: One hundred forty-five (145) consecutive adult patients who had undergone combined anterior and posterior surgery by the senior author for spinal deformity between January 1, 1994 and December 31, 1999 were identified. One hundred thirty-one charts were available for retrospective review (90%). Seventy-seven patients (59%) had undergone their first deformity surgery, and 54 patients (41%) were revision cases. All patients had been followed for at least 2 years. The types and number of complications were identified and divided based on the time of occurrence into perioperative, early (<6 months) and late (>6 months). Complication rates were calculated for the overall group and the rates for primary and revision surgeries were compared.

Results: Ninety-one (91) patients (70%) of the entire study group had at least one complication. The overall complication rate for the patients undergoing primary surgery was lower than the rate for the revision patients (62% versus 80% respectively, p<0.05). Perioperative surgical complications for the primary and revision groups included, respectively: dural tears (6.5% versus 11.1%) and root injuries (1.5% versus 1.3%). Early surgical complications included: early wound infections (7.8% versus 11.1%) and implant failure (9.1% versus 3.7%). Late surgical complications included: pseudarthrosis (4.5% versus 13.3%), late wound infections (1.5% versus 6.7%), symptomatic instrumentation (1.5% versus 13.3%), and junctional disease (7.6% versus 6.6%). There were no permanent cord injuries. The medical complications were also calculated with the most common complication being urinary tract infections for both groups. There were two deaths due to sepsis in the revision group and no deaths in the primary group.

Conclusions: Among patients undergoing anterior-posterior surgery for adult deformity, revision surgery was associated with a higher rate of complications than primary surgery.