Clinical factors associated with bone mineral density among individuals with osteoarthritis of the hip and/or knee: a systematic review

Background and objective: The association of clinical factors of osteoarthritis (OA) with bone mineral density (BMD) is not well understood. We aimed to synthesize evidence regarding the associated clinical factors for low BMD in people with knee and/or hip osteoarthritis. Methods: A systematic literature search limited to human studies was conducted from inception to September 12, 2022. CINAHL, Cochrane, Medline, PsycINFO, PubMed, Web of Science, and African Journal online databases were searched for all clinical factors associated with low BMD (either as osteopenia or osteoporosis). Gray literature or abstracts or protocols, studies with a mixed population of OA without a subgroup analysis for hip and or KOA and non-English were excluded. Following the title and abstract, full-text, screenings, and data extraction, data from eligible studies were synthesized based on the main objective of the study. The Joanna Brigg’s Institute (JBI) Critical Assessment tool was used for quality appraisal. Narrative synthesis and best evidence synthesis were used in the study. Result: Five studies (2 case–control, 3 cross-sectional) were included after screening 3355 titles and abstracts. Clinical factors reported in the five studies included: body mass index (BMI); pain, function, and stiffness; symptom duration; presence of varus/valgus deformity; quality of life; and knee function. Whilst there was limited evidence to support the association between BMD measured at any site of the body and BMI, as well as conflicting evidence for the association of BMD with age and gender, there was insufficient evidence to support the association of BMD with other identified clinical factors of hip and or/ knee OA (p< 0.05). In addition, there is conflicting evidence for the association between BMD measured at the lumbar spine and BMI. Conclusion: There is insufficient evidence on the association between BMD and its associated clinical factors. With the attendant likelihood of bias in existing studies, there is a need for well-designed studies on bone health in OA.