What happens to the hip after scoliosis surgery in neuromuscular patients? Analyzing factors linked to pain, displacement, and need for surgery.

INTRODUCTION

Patients with neuromuscular diseases frequently develop hip displacement (HD) and scoliosis, creating complex challenges in determining the optimal treatment strategy and sequence. This study aims to assess the frequency of new hip problems, including pain and HD progression, as well as the need for additional hip surgery following scoliosis correction in neuromuscular patients, and to identify predictive factors for these issues.

METHODS

This retrospective study included 71 neuromuscular patients (142 hips) who underwent posterior spinal fusion (PSF) at a specialized center between 2015 and 2022. Clinical data such as age, sex, underlying pathology, ambulatory status, and prior hip surgeries were collected. Radiological parameters, including curve characteristics, coronal imbalance, Cobb angle, pelvic obliquity (PO), and migration percentage (MP), were measured pre- and post-operatively. Descriptive, comparative, and multivariate analyses, including logistic regression, were performed to identify significant predictors and determine optimal cutoff points.

RESULTS

The mean age of patients was 15 ± 2 years, with 59% female and 84.5% nonambulatory. After scoliosis surgery, 15.5% of hips developed new hip problems: 20 hips experienced pain and 9 had HD progression, with 7 requiring additional surgery (3 reconstructive and 4 palliative). Factors including a preoperative up-hip and increased MP, with a cutoff > 25%, were strong predictors of hip pain. HD progression was linked to a postoperative up-hip and increased MP, with MP > 60% emerging as a critical predictor. The need for additional hip surgery was associated with cerebral palsy (CP) and with increased MP.

CONCLUSIONS

Approximately 1 in 7 hips developed new-onset problems following PSF in neuromuscular patients. Factors including a preoperative up-hip and increased MP were significant predictors of adverse outcomes, underscoring the importance of thorough preoperative assessment, personalized surgical planning, and proactive counseling regarding potential postoperative complications.

LEVEL OF EVIDENCE: Level IV, retrospective cohort study.