Comparison of Clinical Signs Associated with Lumbar Spine in Patients with Simultaneous Knee Osteoarthritis and Lumbar Spine Osteoarthritis before and after Knee Arthroplasty

Abstract

Background: Knee osteoarthritis (OA) and low back pain (LBP) are common and co-occur in the elderly. The LBP in patients who are candidates for knee arthroplasty affects the outcome and prognosis after surgery. In this study, we investigated the LBP in patients with simultaneous knee and lumbar spine OA after total knee arthroplasty. Methods: In this cross-sectional study, 41 candidates for knee arthroplasty suffering from LBP were included. Demographic and visual analogue scale (VAS) questionnaires for LBP and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire for knee pain and function were completed by patients before surgery. Patients were graded according to VAS index. They were followed up for at least six months to two years. Results: The mean age of 41 patients was 64.30 ± 6.46 years. The mean of the preoperative VAS index was 5.15 ± 2.75, while postoperative VAS decreased to 4.34 ± 3.53 (P = 0.024). Of the total number of patients in preoperative evaluation, 24.4% were in low grades based on the VAS index, followed by moderate (41.5%) and severe (34.1%) grades. The greatest improvement in the VAS index was related to those in mild and moderate grades before surgery. The mean preoperative WOMAC index was 55.1 ± 23.7, while it was postoperatively reduced to 42.9 ± 30.6 (P < 0.001). Postoperative WOMAC was found to be correlated with postoperative VAS (P = 0.004). Conclusion: In patients with mild to moderate LBP and knee OA, their back pain would improve if they had knee arthroplasty. However, in patients with severe LBP and knee OA, the spine should be examined further.