A retrospective study of the relationship between back pain and unilateral knee osteoarthritis in candidates for total knee arthroplasty.

The purpose of this study was to determine the presence and temporal relationship between back pain and knee osteoarthritis (OA). All subjects were candidates for unilateral total knee arthroplasty (TKA) to relieve knee pain related to OA, and information regarding the prevalence of back pain was collected via questionnaires. A total of 42 subjects with unilateral knee OA responded to the questionnaires, and 74% of subjects reported chronic back pain, which first occurred approximately 10 years before their becoming candidates for TKA. All but 1 subject reported the onset of back pain prior to TKA candidacy, and less than 15% of subjects felt that their worst back pain occurred after the onset of knee OA. The results of this study are a first step toward quantifying the temporal relationship between back pain and unilateral knee OA, and future studies will look to assess potential risk factors for knee OA such as strength, biomechanical, and anatomical asymmetry.