Sex related difference in postoperative pain and opioid use following posterior spinal fusion for adolescent idiopathic scoliosis.

PURPOSE: This project aims to evaluate the relationship between biological sex and postoperative pain and in patients receiving posterior spinal fusion for adolescent idiopathic scoliosis.

METHODS: This is a retrospective study of patients (n=137) aged 10-17 receiving posterior spinal fusion for adolescent idiopathic scoliosis between 01/2018 and 09/2022. Each patient received surgery by the same pediatric orthopedic surgeon with identical postoperative pain management regimen at a children's hospital or a tertiary referral center with a pediatric spine program.

RESULTS: There were no significant differences in any background characteristics between the male and female patients, including age, BMI, number of levels fused, preoperative degree of scoliosis, and length of surgery and anesthesia (p>0.05). There were no differences in amount given of any intraoperative medications, nor in amount of postoperative scheduled analgesics (p>0.05). Female patients demonstrated higher average pain scores on Visual Analogue Scale evaluations during the first 24 hours postoperatively (5.0 vs 3.6, p<0.0001), 24-48 hours postoperatively (4.9 vs 4.0, p=0.03), and at the first physical therapy evaluation (5.3 vs 3.8, p<0.001). These patients received significantly greater amounts of morphine milligram equivalents in the first 24 hours postoperatively (42.2 vs 31.5, p=0.01) and for the hospitalization in total (63.8 vs 51.3, p=0.048). There was no difference in hours until hospital discharge (44.3 vs 42.6, p=0.62) nor until first ambulation (20.1 vs 21.3, p=0.24) between the female and male patients.

CONCLUSION: The influence of biopsychosocial factors on postoperative pain in adolescents is complex. This study adds to the existing pool of literature suggesting differences in pain perception between adolescent female and male patients. Female patients undergoing posterior spinal fusion for adolescent idiopathic scoliosis may benefit from increased preoperative counseling and more aggressive intra- and postoperative pain management regimens.