Clinical characteristics and diagnostic and therapeutic effects of bifocal avulsion of patellar tendon in adolescents
CHEN Tian
WEN Yu-wei
ZHU Dan-jiang
FENG Wei
SONG Bao-jian
WANG Qiang
Abstract：Objective To analyze the clinical characteristics and diagnostic and therapeutic effects of bifocal avulsion of the patellar tendon at the inferior pole of the patella and tibial tuberosity. Methods A retrospective study was conducted on the data of 7 adolescent patients with bifocal avulsion of patellar tendon treated at our center from September 2019 to September 2023. Patient demographic characteristics,injury mechanisms,clinical manifestations,imaging findings,surgical procedures,and treatment outcomes were analyzed. Results The average age of 7 patients was 13.6 years old,with males accounting for 85.7％ and an average BMI of 29.1. The mechanisms of injury were all related to excessive passive flexion and torsion of the knee. The diagnostic rate of X-ray for bifocal avulsion of the patellar tendon was only 14.3％;CT was sensitive to identify the subchondral bone avulsion associated with avulsion of the patella,with a diagnostic rate of 100％;MRI was sensitive to identify avulsion of the patellar subpolar periosteum and cartilage,with a diagnostic rate of 100％. Patellar inferior pole injury was treated by direct suture or conservative treatment. Tibial tuberosity injury was fixed with screws for larger bone blocks,and Kirschner wires were used to assist in fixing smaller bone blocks. The patellar tendon rupture at the tibial insertion point was woven and fixed with suture anchors. During a median follow-up of 15 months,the patient achieved complete healing on imaging at an average of 12.3 weeks,regained maximum knee range of motion at 5.3 months,and returned to pre-injury activity at 5.9 months. The average postoperative Lysholm score for the knee was 93.4 points,and the average Tegner score was 6.9 points. Conclusions Bifocal avulsion of the patellar tendon is relatively rare,and the avulsion of the inferior pole of the patella is easily misdiagnosed on X-ray. When there is tenderness in both the inferior pole of the patella and the tibial tuberosity,a clear diagnosis should be made through CT or MRI. Patients can do exercises early to recover good joint and motor function after anatomical reduction and strong fixation.
Keywords：AdolescentPatellar ligamentPatellaFracturesbone
Publication Date：2025-01-18
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 34-40 )