Efficacy of a Multimodal Surgical Site Injection for Postoperative Pain Control in Pediatric Patients With Cerebral Palsy Undergoing Hip Reconstruction: A Randomized Controlled Trial.

Background: One in 4 children with cerebral palsy (CP) will undergo orthopaedic surgery during their childhood. Despite its ubiquity, postoperative pain control has been poorly studied in this patient population. Moreover, poor pain management has been associated with adverse surgical outcomes. Multimodal analgesic injections have been well studied in the adult population, demonstrating safety and efficacy in reducing postoperative pain and narcotic consumption, but this modality has not been studied in pediatric patients undergoing similarly complex procedures. The objective of this study was to evaluate the efficacy of a multimodal surgical site injection for postoperative pain control following operative management of hip dysplasia in patients with CP.

Methods: After obtaining IRB approval, a multicenter, randomized double-blind placebo control trial was completed. Patients below 18 years old with a diagnosis of CP who were scheduled for varus derotation osteotomy (VDRO) of the proximal femur were randomized to receive a surgical-site injection with either a combination of ropivacaine (3 mg/kg), epinephrine (0.5 mg), and ketorolac (0.5 mg/kg) (experimental group) or normal saline (control). All included patients had identical postoperative care, including immobilization, physical therapy, and standardized, multimodal postoperative pain control. Pain scores and narcotic consumption were recorded at regular intervals and compared between groups utilizing two-tailed t test or a nonparametric Mann-Whitney test for quantitative variables and a Fischer exact test for categorical variables.

Results: Thirty-four patients were included, evenly divided between study arms. There were no significant differences in demographic variables, gross motor function classification system (GMFCS), comorbidities, preoperative radiographic parameters, or concomitant surgeries between groups. Patients in the experimental group required significantly lower narcotic medications at all postoperative time points from PACU until hospital discharge compared with controls (0.41 ± 0.42 vs. 1.87 ± 2.05 total morphine mEQ/kg, P=0.01). Similarly, patients in the experimental group were found to have significantly lower pain scores throughout their hospital stays compared with controls (1.0 ± 0.6 vs. 2.4 ± 1.1 mean pain score, P<0.001). There were no significant differences in operative time, OR time, blood transfusion requirements or hospital length of stay between groups. There were no adverse medication reactions or injection site complications in either group.

Conclusions: In patients with CP undergoing hip reconstruction, surgical-site injection with a multimodal analgesic combination improves pain control and reduces narcotic consumption in the early postoperative period with no observed adverse effects.

Significance: Local multimodal analgesic injections should be adopted as part of standard multimodal pain control in this patient population for all osseous surgeries.

Level of evidence: Level I-therapeutic.