Specialty-related differences in diagnosing hip–spine syndrome: a multi-center retrospective cohort study

BACKGROUND: Hip-spine syndrome (HSS) poses a diagnostic challenge because lumbar degenerative disease, sacro-iliac joint dysfunction, and hip osteoarthritis often produce overlapping symptoms. The suboptimal diagnostic pathways may contribute to adverse clinical outcomes. Earlier work suggested that orthopaedic surgeons more consistently obtain hip imaging than neurosurgeons when treating patients who ultimately require both lumbar and hip operations. Whether this observation holds in a tertiary-care electronic medical-record (EMR) setting remains unknown. METHODS: We queried the Chang Gung Research Database (CGRD), the largest multi-institutional EMR repository in Taiwan, for patients aged 50–85 years who underwent both hip arthroplasty and lumbar surgery within the same 12-month period between 2001 and 2024. Cohorts were categorised as hip-then-spine (HS, n = 58), spine-then-hip (SH, n = 223), or simultaneous procedures (Both, n = 2). SH patients were stratified by the specialty of the spine surgeon: orthopaedic (OS, n = 104) versus neurosurgical (NS, n = 111). Primary outcomes were (1) pre-operative ordering of combined spine + pelvis/hip radiography and (2) documentation of hip pathology before spine surgery. Group differences were analysed with χ² or Student’s t tests (α = 0.05). RESULTS: Combined spine-and-hip imaging was obtained significantly more often by OS than by NS (73.1% vs. 51.4%; p < 0.001; FDR q-value: 0.002). Hip osteoarthritis or osteonecrosis was recorded pre-operatively in 26.9% of OS cases versus 21.6% of NS cases, a non-significant difference attributable to limited sample size (p = 0.364). The SH:HS ratio showed approximately 4:1, indicating that spine surgery typically precedes hip arthroplasty in routine practice. CONCLUSIONS: Within a tertiary-care EMR database, orthopaedic surgeons were more likely than neurosurgeons to order comprehensive spinopelvic imaging, thereby enhancing detection of hip pathology in patients with suspected HSS. These findings underscore the importance of mandated and standardized pre-operative hip/pelvic imaging before lumbar surgery and support efforts to harmonise diagnostic protocols across specialties.