To investigate the effect of patellar reduction combined with lateral patellar retinaculum release on the occurrence of anterior knee pain and the knee joint function after total knee arthroplasty (TKA).

A total of 136 cases (136 cases) were collected from the Department of Orthopaedics, Second Hospital of Traditional Chinese Medicine, Guangdong Province between January 2016 and June 2017, excluding ipsilateral hip disease and severe internal and external valgus deformity knees. Before the operation, the patients were divided into two groups according to random distribution (patellar reduction combined with lateral patellar retinaculum release during operation, 68 cases), and the control group (removal of patella edge hardening bone but no lateral patellar retinaculum release, 68 cases); all the operative procedures were consistent. Preoperative and postoperative knee pain and complications, operation time, American Hospital of Special Surgery (HSS) score, patella Feller score, and anterior knee pain score were recorded before and after the surgery. X-ray film of knee joint and Merchant position (30 ° patella axis) were taken after operation to observe the patellar tracking. Chi-square test and t test were used to analyze the data.

Three patients in the observation group were lost to follow up, and two patients were injured in the tibia. In the control group, seven patients underwent a "no thumb" test and found that the lateral patellar retinaculum needed to be released, they were not not involved in this research.The two groups eventually included 63 patients and 61 patients. All the patients got the follow-up at the same time. The preoperative knee pain rate was 4.8% (3/63) in the observation group and 16.4% (10/61) in the control group. The observation group was superior to the control group, and the different was significant (t=6.325, P<0.05). There was no obvious difference between the two groups in the operation time (P>0.05). At 18 months after operation, the HSS score, Feller score, anterior pain of knee score and knee joint activity were improved significantly in both groups (P <0.05). However, the HSS score, patella Feller score and anterior knee pain score were observed in the observation group, and the different was significant (t=3.125, P<0.05). There was no complication such as patellar necrosis, patellar fracture and patellar hypertension in the two groups, and there was no obvious difference between the two groups (P>0.05). There were two patients in the observation group and 11 patients in the control group with bad patellar tracking, and the difference was significant (t=11.218, P <0.05).

In the knee arthroplasty, patellar reduction combined with lateral patellar retinaculum release can reduce the incidence of anterior knee pain and complications significantly, improve knee function and maintain patellar tracking well, and improve the curative overall effect of TKA.