Spine-Abductor Syndrome: Novel Associations Between Lumbar Spine Disease and Hip Gluteal Muscle Pathology.

Background: Risk factors for gluteal tears include age-related deterioration, female sex, and increased body mass index. As the literature that supports the sagittal relationship between the lumbar spine and the hip is increasing, there may be a parallel relationship between the perturbations in spinopelvic alignment caused by lumbar spine disease and gluteal muscle tears. Because no prior studies other than single-institution series have reported on this phenomenon, we investigated spine-abductor syndrome at the population level.

Methods: This study utilized TriNetX, a federated research network that continuously aggregates deidentified electronic health record data from >92 million patients across the United States. The relative risks of gluteal tear encounter diagnoses and procedures were calculated for patients with and without the following characteristics: age ≥45 years, female sex, obesity, lumbar spine diagnoses, lumbar spine injections, and lumbar spine surgery. Utilizing the Cox proportional hazard model, we also analyzed gluteal tear-free survival over a period of ≥10 years in subgroups of patients who had been diagnosed with lumbar pathology, had been administered a lumbar injection, or had received lumbar surgery.

Results: Of the 8,475,800 patients who had received lumbar spine diagnoses, undergone lumbar injections, and/or undergone lumbar surgeries, 458,311 patients (5.4%) had gluteal tears, representing a relative risk of 13.6 (95% confidence interval [CI]:13.6 to 13.6). After controlling for age, sex, and obesity, survival analysis showed markedly increased hazard ratios (HRs) for patients having a gluteal tear encounter diagnosis in the intervening 13 years (2010 to 2023) if they had had a previous lumbar spine pathology encounter diagnosis (HR: 4.8, 95% CI: 4.5 to 5.1), had undergone lumbar spine injections (HR: 7.7, 95% CI: 6.2 to 9.5), or had undergone lumbar spine surgery (HR: 6.6, 95% CI: 5.3 to 8.1) in 2010.

Conclusions: These findings suggest a strong association between lumbar spine pathology and abductor tears. Further biomechanical and neuroanatomic studies may elucidate the effects of lumbar spine disease in relation to gluteal tears. Additionally, there may be a need to optimize diagnostic protocols for lateral hip pain in patients with a history of lumbar spine disease.

Level of evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.