A retrospective analysis was performed involving 29 patients who visited the North Jiangsu People's Hospital with tibial insertion avulsion fractures of the ACL and were treated with arthroscopic reduction using a single tunnel with double-strand nonabsorbable suture anchors from January 2014 to June 2018. Each enrolled patient provided signed informed consent, and the study was approved by the Institutional Ethics Committee. A total of 29 patients, including 15 males and 14 females, age ranging from 8-66 years, with a mean age of 32.59 years, visited the emergency department for ACL tibial insertion avulsion fractures; none of the patients had cruciate ligament injuries or any other fractures. The inclusion criterion was displaced ACL tibial insertion avulsion fractures in both skeletally mature and immature patients. Patients with vessel injuries, nerve injuries, tibial plateau fractures, and other significant injuries, including osteochondral lesions, or posterior cruciate ligament (PCL), ACL, and multi-ligament injuries, were excluded from the study. The number of days before surgery was 3-61 days, and the average number of days before surgery was 8.55 days. The patients had varying degrees of knee pain and instability after injury, accompanied by swelling and pain in the knee joint after exercise. Before the operation, all physical tests were performed by the same doctor; the anterior drawer test (ADT) and the Lachman test were positive, which indicated anterior instability exceeding 5 mm. All patients underwent X-ray, computed tomography (CT), and MRI before surgery (Fig. 1). Among these patients, five had meniscal injuries and two had collateral ligament injuries. The preoperative Lysholm knee score was 51.14 ± 2.34, and the preoperative International Knee Documentation Committee (IKDC) subjective score was 51.24 ± 3.16. According to the Meyers-McKeever fracture classification, there were eight cases of type II fractures and 21 cases of type III fractures.
Patients were placed in the supine position, spinal or general anesthesia was applied, a tourniquet was placed to prevent bleeding, and arthroscopy was performed to check the ACL, PCL, and meniscus for better understanding of the damage and treatment needed for the combined injury. Blood clots and the soft tissue between the fracture blocks were cleared, and the fracture block was reset. The optimal bone tunnel was determined in front of the ACL and it was also determined whether the ACL was fixed. The knee was bent at 90°, and the ACL tunnel locator was placed through the anteromedial approach. The point was located at the inner end of the tunnel for optimal fracture reduction. Under the guidance of the positioner, a longitudinal incision of approximately 0.6 cm was made at the positioning point of the tibial tuberosity inside the tibial tuberosity, and a 2 mm Kirschner wire was drilled along the positioner. The ACL tibia tunnel locator was removed, and a 4.5 mm drill was used to enlarge the bone tunnel along the Kirschner wire. Through the anteromedial approach, a shoulder rotator cuff suture was placed through the posterior 1/3 or middle of the ACL base, and the ACL was sewn through the rotator cuff suture with PDS-II (ETHICON, LLC, USA). Pliers were placed through the bone tunnel, and the PDS-II was pulled out through the ligament of the anterior ligament. The two ends of the PDS-II were removed from the joint cavity. One of the high-strength lines from the Ti 5.0 mm with a double-strand #2 preloaded ULTRABRAID suture anchor (Smith & Nephew Inc, Andover, MA 01810, USA) was tied to one end of the PDS-II line. The PDS-II was extended and one end of the high-strength line was pulled out from the joint through the tunnel, while the other end of the high-strength line was pulled out of the joint through the bone tunnel using pliers. The 5.0 mm suture anchor had been removed from one of the high-strength lines before it was placed beside the tunnel mouth. The high-strength line through the tunnel was knotted first with one side of the other high-strength line under the knot, and then the other high-strength line was knotted tightly. Finally, the joint cavity was checked under arthroscopy, and the fracture block was fixed using staples (Fig. 2).
Postoperatively, the wound in each patient was covered with compression dressing for 3 days, and a brace was fixed for 6 weeks. Under the protection of the brace, patients were encouraged to undergo long-term contraction and straight leg raise training for the quadriceps. Static knee training was started one week after the operation, and the knee joint activity was gradually increased to 90° in the fourth week. In the sixth week, the knee joint activity was required to be > 120°. At this time point, the brace could be removed for functional exercises, and the patients could resume normal activity at 3 months. Follow-up and evaluation indicators: All 29 patients were followed up for 12 months. X-ray films were taken at a monthly interval to determine fracture reduction and healing. During the follow-up period, CT and MRI were performed to evaluate reduction and healing (Fig. 3). The Lachman test and ADT were performed by the same doctor to determine knee joint stability. The Lysholm score and IKDC subjective score were used to evaluate postoperative knee function recovery.
Statistical analysis was performed using the SPSS23.0 (IBM Corp). Data were expressed as the mean ± standard deviation, and paired t-tests were used for comparison between groups; test level α = 0.05. P values < 0.05 were considered statistically significant.