Does Postoperative Ketorolac Predispose to Pseudoarthrosis Following Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis?

Purpose: Ketorolac (Toradol, Roche Laboratories) is a nonsteroidal anti-inflammatory drug (NSAID) that is an effective adjunct to treat postoperative pain following a posterior spinal fusion and instrumentation (PSFI) for adolescent idiopathic scoliosis (AIS). It has been previously demonstrated to inhibit spinal fusion in adult patients undergoing an L4 to sacral fusion. However, there are no large studies analyzing this effect following PSFI for AIS.

Methods: Following IRB approval, a retrospective medical record review was performed from 1994 to 2000 of patients undergoing a PSFI for AIS from a single institution. Segmental spinal instrumentation and iliac crest bone graft were used in both groups. Demographic and operative data were recorded. The dose, and duration of ketorolac and other NSAIDS were recorded. Patients were divided into those who had postoperative ketorolac (group K) and those who did not have posteroprative ketorolac (group NK). Patients who had a pseudoarthrosis were identified. The Student’s t test was used to compare the two groups and statistical significance was defined as P<0 .05.

Results: S: There were 133 patients in the K group and 131 in the NK group. There were no differences between the K and NK groups with respect to age (14.4 vs 14.1 years), gender (85.0% vs 84.1% females), race, levels fused (9.5 vs 9.6), and preoperative curve magnitude (58.3E vs 57.2E). The most common curve patterns were King 3 (46.6 vs 49.6%), King 2 (21.8 vs 22.9%), and double major curve pattern (11.3 vs 12.2%) for the K and NK groups. The average dose of ketorolac was 26.4 mg every 6 hours for an average duration of 46 hours postoperatively in the K group. The patients in the K group were more likely to have Motrin (average 5.9 doses) compared to the NK group (average 0.1 doses). (P<0 .01) No patient in the K group had a history of cigarette smoking compared to 2 patients NK group, both whom went on solid arthrodesis. The incidence who developed pseudoarthrosis was 3.0% (4 133) and 3.8% (5 131) (P="0.18)." Because single rods predispose pseudoarthrosis, an analysis treated with dual performed demonstrated no significant difference when ketorolac used (3.6%) it not (0.9%)

Conclusions: When performing a PSFI for AIS using segmental spinal instrumentation and iliac crest bone graft, there does not appear to be an increased incidence of developing a pseudoarthrosis when ketorolac is used as an adjunct for postoperative analgesia.