[A case-control study of two internal fixation methods in the treatment of comminuted fracture of inferior pole of patella].

OBJECTIVE: To compare the effects of tension band combined with patellar cerclage and memory alloy patellar concentrator fixation in the treatment of comminuted fracture of the lower pole of patella. METHODS: From July 2015 to July 2019, 60 patients with distal patellar fracture were treated and were divided into two groups according to different operation methods. In group A, 30 patients were fixed with memory alloy patellar concentrator (NiTi PC), 17 males and 13 females, aged 20 to 71 (39.4±9.9) years, including 19 cases of falling injury, 9 cases of traffic injury and 2 cases of sports injury. The time from injury to operation was 10 to 75 (33.1±7.8) hours; 30 cases in group B were fixed with tension band andcerclage, 15 males and 15 females, aged 21 to 76 (38.6±10.2) years, including 17 cases of falling injury, 12 cases of traffic injury and 1 case of smashing injury. The time from injury to operation was 10 to 91 (34.5±9.1) hours. The curative effects of two groups were observed and compared. RESULTS: All 60 patients were followed up for 9 to 30 months. There was no significant difference in intraoperative bleeding, operation time, follow-up time and fracture healing time between the two groups. Six months after operation, according to the Bostman function score of knee joint:30 cases in group A, the total score was 28.6±4.7, of which 26 cases were excellent and 4 cases were good. The total score of 30 cases in group B was 25.5±4.4, of which 20 cases were excellent, 8 cases were good and 2 cases were poor. There were significant differences in Bostman total score and curative effect evaluation between two groups (P<0.05). The score of group A was significantly better than that of group B. In group B, 1 case had Kirschner wire withdrawal, 2 cases had joint stiffness and 3 cases had internal fixation irritation. CONCLUSION: Memory alloy patellar concentrator is strong and reliable in the treatment of inferior patellar fracture. It can take early rehabilitation exercise after operation, with good recovery of joint function and range of motion and less complications.