Abstract
BACKGROUND: Low back pain (LBP) is commonly reported in people with hip osteoarthritis (OA) and is a poor prognostic indicator of outcome in OA. This study aimed to identify the clinical features associated with LBP in people with hip OA attending orthopaedic and rheumatology clinics. METHODS: A cross-sectional study was undertaken. Twenty-four people with radiographically confirmed OA were recruited and completed self-report questionnaires for hip and LBP severity (Visual Analogue Scale), hip-related disability (Western Ontario and McMaster Universities Osteoarthritis Index) and back-related disability (Roland Morris Disability Questionnaire). Physical examination comprised spinal palpation, pelvic girdle pain provocation tests and hip and spinal range of motion tests. Between-group (presence/absence of LBP) differences in self-report and physical examination items were compared using Mann-Whitney U and Chi-squared tests. RESULTS: A total of 16/24 (66.7%) patients reported LBP. Those with LBP were younger, reported more pain locations and had higher self-report pain and disability. On physical examination, people with LBP and OA hip had reduced hip flexion, greater pain provocation with hip abduction, hip lateral rotation, spinal palpation and a greater number of painful pelvic girdle tests and spinal level palpation. CONCLUSIONS: Assessment of patients with hip OA should incorporate examination of the lumbar spine and pelvic regions. It appears from our study that LBP is a common co-morbidity in those with OA of the hip and may indicate greater severity of hip disease, although the small sample size limits interpretation of results. Further research should investigate the exact relationships between presence of LBP and hip OA.