Radiographic assessment of lumbar spine degeneration in patients with total hip arthroplasty: a cross-sectional study

Lumbar spine degeneration and hip osteoarthritis (HOA) commonly coexist with aging. Although spinopelvic parameters have been widely investigated, radiological patterns of lumbar degeneration in the context of total hip arthroplasty (THA) remain poorly understood. This study aimed to characterize and compare lumbar degenerative imaging findings between patients with a history of THA for HOA and a comparable control group.

Patients with prior THA were compared with a control group regarding subcutaneous fat tissue thickness (SFTT), subcutaneous fat index (SFI), intervertebral disc degeneration (IVDD), Modic changes, Schmorl's nodes (SNs), and fatty infiltration in the lumbar paraspinal muscles across all lumbar levels.

A total of 235 patients with chronic low back pain were analyzed (THA group, n = 116; control group, n = 119). There were no significant differences between groups in IVDD severity, Modic changes, or fatty infiltration in their paraspinal muscles. The THA group exhibited significantly higher SFI and SFTT. SNs were more prevalent in patients who had undergone THA. Multivariable regression analysis showed significant independent associations between THA status and SFI (OR 1.481), SFTT at L3-L4 (OR 0.892), and SNs at L1-L2 (OR 5.186).

SNs at L1-L2 and higher SFI were the factors most strongly associated with a history of THA. These findings highlight distinct morphological features in the hip-spine population, though the nature of these interrelationships remains to be elucidated. Prospective longitudinal studies are warranted to clarify the temporal dynamics of hip-spine interactions.