Abstract
Background
Despite the excellent clinical success of total knee arthroplasty (TAK), controversy remains concerning whether or not to resurface the patella. This has led to a number of randomized controlled trials. Randomized controlled trials constitute the most reliable source of evidence for the evaluation of the efficacy of a potential intervention. But most of these studies include all degree of osteoarthritis of the patellofemoral joint. So we did this prospective study to compare clinical and radiological outcomes after TKA with or without patellar resurfacing in patients with grade IV osteoarthritis on patellofemoral joint.
Materials and Methods
123 cases (93 patients) with Kellgren-Lawrence grade IV osteoarthritis on patellofemoral joint were enrolled for this study. At the operating room, they were randomly assigned to undergo patella resurfacing (62 cases) or patella retention (61 cases). Among them, 114 cases that could be followed for more than 2 years were included in this study (resurfacing group; 59 cases, retention group; 55 cases). When patellar retention was performed, osteophytes of the patella were removed and marginal electrocauterization was carried out. Preoperative and postoperative clinical outcomes were evaluated and compared regarding the Hospital for Special Surgery Patellar (HSSP) score (total 100 point; anterior knee pain, functional limitation, tenderness, crepitus, Q-strength). We also compared Hospital for Special Surgery (HSS) and WOMAC scores, and range of motion (ROM). We also compared radiological outcomes at the final follow up, with regards to mechanical axis of the lower limb, patella tilt and patella congruence angle between two groups.
Results
Average HSSP score was 85 in resurfacing group, 83 in retention group, which were showing no significant differences between groups (p=.75). Anterior knee pain subscale also showed no significant differences between groups (40 in resurfacing group, 36 in retention group, p= 0.52). HSS score improved to 94 points in resurfacing group and 95 points in retention group showing no significant difference (p=.92). While WOMAC score and range of motion was 32 point and 128°±10.5° in resurfacing group, respectively, they were 29 point and 126°±11.5° in retention group, without significant inter-group difference (p>.05). There were no differences between two groups in mechanical axis of the lower limb and patella tilt, patella congruence (p>0.05).
Conclusion
Clinical and radiological outcomes were ‘good’ after TKA with or without patellar resurfacing in patients with high grade osteoarthritis of the patellofemoral joint without significant differences. Thus, this study suggested that TKA without patellar resurfacing is a good treatment option in patients with high grade osteoarthritis of the patellofemoral joint.
