Impact of coexistent lumbar spine disorders on clinical outcomes and physician charges associated with total hip arthroplasty.

BACKGROUND CONTEXT: Despite the common prevalence of lumbar spine and degenerative hip disorders, there are few descriptions of patients with coexisting hip disorders and lumbar spine disorders (LSDs). The independent economic burden of each disorder is substantial, but the financial burden when the disorders are coexisting is unknown.

PURPOSE: To determine the prevalence of coexisting hip disorders and LSDs in a large cohort of patients with hip osteoarthritis (OA) treated with total hip arthroplasty (THA) as well as the impact on pain and functional THA outcomes and physician charges.

STUDY DESIGN: This is a retrospective study performed at a tertiary university.

PATIENT SAMPLE: Three thousand two hundred six patients underwent total hip replacement from 1996 to 2008.

OUTCOME MEASURES: Self-report measures: visual analog scale. Functional measures: modified Harris Hip Score (mHHS) and University of California Los Angeles (UCLA) hip questionnaire. Economic impact measures: physician medical charges.

METHODS: International Classification of Diseases, Version 9, billing codes related to LSDs were cross-referenced with the 3,206 patients who had undergone a THA to determine which patients were also evaluated by a spine specialist. Demographic, hip clinical outcomes, and physician charges for patients with THA alone (THA alone) were compared with patients treated with THA and diagnosed with an LSD (THA+LSD).

RESULTS: Of 3,206 patients who underwent THA, 566 (18%) were also evaluated by a spine specialist. Of those with an LSD, 334 (59%) were women with an older average age (64.5 ± 13.3 years) compared with patients treated with THA alone (51%, 58.5 ± 15.5 years, p = .0001). Patients in the THA alone group as compared with the THA+LSD group had greater improvement in the mHHS (p=.0001), UCLA score (p=.0001), and pain (p=.0001). Patients in the THA+LSD group incurred on average $2,668 more in charges per episode of care as compared with patients in the THA alone group (p<.001). Patients in the THA+LSD group had more days per episode of care (p=.001).

CONCLUSIONS: Patients undergoing THA alone had greater improvement in function and pain relief with fewer medical charges as compared with patients undergoing a THA and treatment for an LSD. The prevalence of coexisting hip disorders and spine disorders is likely higher than currently documented. Further study is needed to improve therapeutic recommendations and determine the potential for reduction in medical expenses associated with concurrent treatment of hip OA and LSDs.