Orthopedic disease burden in adult patients with symptomatic lumbar scoliosis: results from a prospective multicenter study.

OBJECTIVE Although the health impact of adult symptomatic lumbar scoliosis (ASLS) is substantial, these patients often have other orthopedic problems that have not been previously quantified. The objective of this study was to assess disease burden of other orthopedic conditions in patients with ASLS based on a retrospective review of a prospective multicenter cohort. METHODS The ASLS-1 study is an NIH-sponsored prospective multicenter study designed to assess operative versus nonoperative treatment for ASLS. Patients were 40-80 years old with ASLS, defined as a lumbar coronal Cobb angle ≥ 30° and Oswestry Disability Index ≥ 20, or Scoliosis Research Society-22 questionnaire score ≤ 4.0 in pain, function, and/or self-image domains. Nonthoracolumbar orthopedic events, defined as fractures and other orthopedic conditions receiving surgical treatment, were assessed from enrollment to the 4-year follow-up. RESULTS Two hundred eighty-six patients (mean age 60.3 years, 90% women) were enrolled, with 173 operative and 113 nonoperative patients, and 81% with 4-year follow-up data. At a mean (± SD) follow-up of 3.8 ± 0.9 years, 104 nonthoracolumbar orthopedic events were reported, affecting 69 patients (24.1%). The most common events were arthroplasty (n = 38), fracture (n = 25), joint ligament/cartilage repair (n = 13), and cervical decompression/fusion (n = 7). Based on the final adjusted model, patients with a nonthoracolumbar orthopedic event were older (HR 1.44 per decade, 95% CI 1.07-1.94), more likely to have a history of tobacco use (HR 1.63, 95% CI 1.00-2.66), and had worse baseline leg pain scores (HR 1.10, 95% CI 1.01-1.19). CONCLUSIONS Patients with ASLS have high orthopedic disease burden, with almost 25% having a fracture or nonthoracolumbar orthopedic condition requiring surgical treatment during the mean 3.8 years following enrollment. Comparisons with previous studies suggest that the rate of total knee arthroplasty was considerably greater and the rates of total hip arthroplasty were at least as high in the ASLS-1 cohort compared with the similarly aged general US population. These conditions may further impact health-related quality of life and outcomes assessments of both nonoperative and operative treatment approaches in patients with ASLS.