Prevalence of multimorbid degenerative lumbar spinal stenosis with knee or hip osteoarthritis: a systematic review and meta-analysis

Background: Musculoskeletal multimorbidity is common and coexisting lumbar spinal stenosis (LSS) with knee or hip osteoarthritis (OA) has been reported. The aim of this review was to report the prevalence of multimorbid degenerative LSS with knee or hip OA based on clinical and/or imaging case definitions. Methods: Literature searches were performed in MEDLINE, EMBASE, CENTRAL, and CINAHL up to May 2021. Studies involving adults with cross-sectional data to estimate the prevalence of co-occurring LSS with knee or hip OA were included. Study selection, data extraction, and risk of bias assessment were performed independently by two reviewers. Results were stratified according to index and comorbid condition, and by case definitions (imaging, clinical, and combined). Results: Ten studies from five countries out of 3891 citations met the inclusion criteria. Sample sizes ranged from 44 to 2,857,999 (median 230) and the mean age in the included studies range from 61 to 73 years (median 66 years). All studies were from secondary care or mixed settings. Nine studies used a combined definition of LSS and one used a clinical definition. Imaging, clinical, and combined case definitions of knee and hip OA were used. The prevalence of multimorbid LSS and knee or hip OA ranged from 0 to 54%, depending on the specified index condition and case definitions used. Six studies each provided prevalence data for index LSS and comorbid knee OA (prevalence range: 5 to 41%) and comorbid hip OA (prevalence range: 2 to 35%). Two studies provided prevalence data for index knee OA and comorbid LSS (prevalence range 17 to 54%). No studies reporting prevalence data for index hip OA and comorbid LSS were found. Few studies used comparable case definitions and all but one study were rated as high risk of bias. Conclusions: There is evidence that multimorbid LSS with knee or hip OA occurs in people (0 to 54%), although results are based on studies with high risk of bias and surgical populations. Variability in LSS and OA case definitions limit the comparability of studies and prevalence estimates should therefore be interpreted with caution.