Poster 262: The risk factors associated with failure results after arthroscopic repair for bucket handle meniscal tear. A multi-center study

OBJECTIVES: Meniscal tears are one of the common knee injuries. Large size of longitudinal-vertical tear is called bucket handle tear, and easily displaced and locked in the knee joint cavity. This type of injury is usually required arthroscopic intervention due to pain or dysfunction such as loss of range of motion of the knee. Recently, the arthroscopic meniscal repair technique and devices have been developed and reported good results. The inside-out technique, outside-in technique, and all-inside technique are well known. However, 20 to 34.2% of failure cases after primary meniscal repair were reported. The purpose of this study is to identify the risk factors to associate with the postoperative failure of bucket handle meniscal tear under multi-center study. METHODS: PATIENTS: The present study was conducted in 2021, involving patient who was diagnosed and performed primary arthroscopic meniscal repair surgery for bucket handle meniscal tear at four orthopaedic centers. The study followed retrospective observational design including data collected from Jan 2000 to Aug 2021. The experimental design was reviewed and approved (Accession No. 0-0956) by the Ethics Committee of our institute. The procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2000. Inclusion criteria were the cases of knee bucket handle meniscal tears which were diagnosed clinically and by MRI testing. Exclusion criteria were following; postoperative observation period was less than 12 months cases, meniscal posterior root tear cases, could not obtain full surgical and clinical information cases, infection and inflammatory disease cases, and meniscal resection cases. Senior orthopaedic surgeons were diagnosed and performed arthroscopic surgery in each center. Surgical and clinical information were obtained from four orthopaedic centers. Total 95 bucket handle tear cases were enrolled in this study. Patients were analyzed on an average of 27.14 ± 24.8 months after surgery by the use of Marx score (MS) and Tegner Activity Scale (TAS). To identify factors associated with postoperative failure, we obtained the following information; age, body mass index (BMI), height, weight, injury to surgery duration, postoperative immobilization period, postoperative non-weight bearing period, timing of full-weight bearing, timing of running, presence of knee ligament rupture, medial or lateral meniscus, total number of sutures. Moreover, the number of each suture technique such as inside-out, outside-in, and all-inside method were analyzed. Location of injury such as white-white (WW) zone, red-white (RW) zone, and red-red (RR) zone was also analyzed. Statistical comparisons between the two groups were performed using the 2x2 chi-squared test, t-test, the Mann Whitney U-test. Risk factors of postoperative failure case were determined with multiple logistic regression analysis. The level of significance was set at P < 0.05. RESULTS: There were 69 patients (male: 32, female:37) with healed and 26 (27.4%, male: 12, female: 14) that sustained failure after primary meniscal repair. There were no significantly difference between healing group and failure group in injury to surgery duration (39.7 vs 22.4 days, p=0.65), height (165.2 vs 163.8 cm, p= 0.52), weight (67.2 vs 60.1 kg, p=0.09), postoperative immobilization period (2.0 vs 1.95 weeks, p=0.56), postoperative non-weight bearing period (2.89 vs 2.67 weeks, p=0.34), timing of full- weight bearing (5.60 vs 5.62 weeks, p=0.69), timing of running (3.4 vs 4.75 months, p=0.41), preoperative TAS (5.48 vs 6.08, p=0.33), postoperative TAS (4.50 vs 5.33, p=0.34), postoperative Marx score (6.36 vs 9.17, p=0.59). In the healing group, MM/LM was 48/21 and 21/5 in the failure group (p=0.28). Location of tear in the hearing group was following; RR / RW / WW as 29 / 27 / 3, and failure group was 11 / 9 /2 (p=0.78). Combined knee ligament injury was observed 50 cases in the healing group, and 20 cases in the failure group (p=0.48). Total number of sutures was 4.66 vs 3.85 (p=0.24). The numbers of each suture technique were 2.91 vs 2.88 (p=0.67) in all-inside method, 2.33 vs 2.00 (p=0.8) in outside-in method. On the other hand, the number of inside-out method in the healing group was significantly higher than that of failure group (3.56 vs 2.33, p=0.02, number of inside-out method. OR: 0.339, 95%CI; 0.132-0.873, p=0.02). Additionally, BMI of healing group was higher than failure group with significance (24.39 vs 22.32, p=0.05). Age of healing group was also significantly higher than failure group (26.0 vs 22.3, p=0.05). CONCLUSIONS: Failure rate of primary repair for bucket handle tear was 27.4% in this multi-center study. Lower numbers of inside-out suture technique and low value of BMI and age were significantly associated with postoperative failure.