Effect of patellar tilt angle after total knee arthroplasty without patellar resurfacing / 中华骨科杂志

ABSTRACT

Objective:To analyze the effect of patellar tilt angle on postoperative outcomes after total knee arthroplasty (TKA) without patella resurfacing.Methods:A total of 143 patients with end-stage knee osteoarthritis who underwent TKA without patellar replacement in the First Affiliated Hospital of Nanjing Medical University from October 2020 to October 2021 were retrospectively analyzed. There were 32 males and 111 females, aged 68.44±6.79 years (range, 52-86 years). Patients were divided into three groups according to the postoperative patellar tilt angle tilt angle<5° was the mild tilt group (97 cases), 5°≤tilt angle<10° was the moderate tilt group (31 cases), and tilt angle≥10° was the severe tilt group (15 cases). All patients were followed up in the outpatient clinic at 3, 6 and 12 months after surgery, and knee visual analogue score (VAS), Hospital for Special Surgery (HSS) score and patella Feller score were observed and recorded to compare the postoperative knee pain and function of patients in different patella tilt groups.Results:All patients were followed up for 1.16±0.23 years (range, 1.0-2.0 years). There was no significant difference in baseline data between the groups. There were significant differences in the intra-group comparison of the VAS score before and after surgery among the three groups ( F=51.12, P<0.001; F=36.90, P<0.001; F=15.76, P<0.001). The VAS scores at 3, 6 and 12 months after operation were significantly lower than those before operation ( P<0.05). The knee VAS of the severe group was higher than that of the mild and moderate groups at 3, 6 and 12 months after surgery, and the difference was statistically significant ( P<0.05). There were statistically significant differences in knee HSS scores before and after surgery among the three groups ( F=81.12, P<0.001; F=36.05, P<0.001; F=32.93, P<0.001). The knee HSS scores at 3, 6 and 12 months after surgery were higher than those before surgery, and the difference was statistically significant ( P<0.05). The knee HSS scores of the severe tilt group at 3, 6 and 12 months after surgery were lower than those of the mild and moderate groups, and the difference was statistically significant ( P<0.05). There were statistically significant differences in the intra-group comparison of the patella Feller score before and after surgery among the three groups ( F=88.81, P<0.001; F=49.59, P<0.001; F=37.40, P<0.001). The patellar Feller score at 3, 6 and 12 months after surgery was higher than that before surgery, and the difference was statistically significant ( P<0.05). The patellar Feller score of the severe group at 3, 6 and 12 months after surgery was lower than that of the mild and moderate groups, and the difference was statistically significant ( P<0.05). Conclusion:Patellar tilt angle after TKA without patellar resurfacing will increase knee pain and limit joint function.