Effects of bilateral knee arthroplasty on sagittal spinopelvic balance in patients with primer degenerative osteoarthritis

Abstract

Aim: We aimed to evaluate the change in sagittal spinopelvic parameters in knee osteoarthritis patients without prior degenerativespinal disease following bilateral knee arthroplasty. Knee osteoarthritis often causes knee flexion contracture and the flexioncontracture may affect posture and lumbar lordosis.Material and Methods: We performed a retrospective study by evaluating the records of patients who have undergone bilateralknee arthroplasty in our clinic between 2012 and 2016 in patients due to degenerative bilateral knee osteoarthritis and minimum 12months follow up. Patients with prior hip surgery, prior spine surgery, rheumatic disease and postoperative flexion contracture wereexcluded. Lumber lordosis, sacral slope, pelvic tilt and pelvic incidence were measured on lateral lumbosacral view in supine positionpre-postoperatively and compared with paired T test. Extension deficit was also measured preoperatively.Results: This study includes 83 patients (77 females and 6 males) who underwent bilateral knee arthroplasty and matched theinclusion and exclusion criteria. The average age at the time of first total knee arthroplasty was 64.4 years. Mean follow up was37.3(12-66) months. The mean lumber lordosis was 43.9° preoperatively and 49.6° postoperatively. The increase in lumbar lordosisangle was statistically significant (p: 0,001). These changes were only related to the degree of extension deficit but not to age andpostoperative follow-up time. Sacral slope, pelvic incidence and pelvic tilt did not change significantly.Conclusion: Bilateral knee arthroplasty increased lumbar lordosis patients with primer degenerative osteoarthritis especially whohad high extension deficit. Sacral slope and pelvic tilt were decreased postoperatively but not significantly changed.