General Information
A total of 48 patients with complete rupture of PCL treated in our hospital from July 2015 to February 2017 were selected and divided into the Group A (25 cases) and the Group B (23 cases) according to the different grafts. The group A was reconstructed with double strands peroneus longus tendon while and the group B was with four strands hamstring tendon. There were no significant differences between the two groups in sex, age, BMI value or causes of injury (Table I). This study was approved by the Ethics Committee of Affiliated Hospital of Nantong University. Signed written informed consents were obtained from all participants before the study.
PCL diagnosis and exclusion criteria
PCL injury could be classified into three types according to severity: I0, II0 and III0. Patients with II0 or III0 have complete tendon rupture, which requires surgical treatment. exclusion criteria: (1) Patients with peri-knee fracture, infection and neurovascular injury; (2) MR imaging confirmed that subjects with other stable structural injuries of the knee joint (anterior cruciate ligament (ACL), medial collateral ligament (MCL), etc.). (3) Patients with previous history of knee arthritis or other chronic diseases; patients with severe osteoporosis.
Surgical methods
After routine preoperative preparation and anesthesia, all patients were examined by arthroscopy to determine the injury of patients. In order to obtain the long peroneal tendon, we made a longitudinal incision (proximal incision) about 2 cm long at the middle and lower 1/3 of fibula in group A to expose the long peroneal tendon. Repair tendon, measure length, fold into two strands after knitting, forming columnar tendon bundle. In group B: The tendon of semitendinosus and gracilis tendon were dissected through a longitudinal incision about 3 cm long on the medial side of the affected tibial tubercle. The tendon was removed proximally with a closed-mouth key harvester. The tendon was repaired and the length was measured. The semitendinosus and gracilis tendons are woven and folded into four strands (2 strands per share, 4 strands in total) to form tendon bundles. The details of the operation and postoperative rehabilitation are described below: The central point of the femoral tunnel is located at 1:30 (right), 12 mm from the cartilage at the top of the intercondylar fossa, and 7-8 mm from the nearest cartilage margin at the far side. Tibial tunnel: the outer mouth is located at the medial side of tibial tubercle, and the inner mouth is located at the proximal part of the epiphyseal slope of tibial metaphysis 5 mm. Graft fixation methods was extrusion or suspension of interface screw. When the tendon is installed, the knee joint should be treated at 90 degrees of flexion. After operation, ankle pump exercise, quadriceps isometric contraction exercise, hamstring isometric contraction exercise within 1 week after operation, 2 weeks after the operation, we continued to strengthen the practice of upper operation, passive flexion 60 degrees in case of slight pain, once a day; 3 weeks after the operation, passive flexion 90 degrees, with brace 30 to 50 degrees range of activity, 4 weeks after the operation, passive flexion more than 90 degrees close to 100 degrees, after leg lifting exercise and balance exercise. 5-8 weeks postoperatively, the passive flexion was 110-120 degrees, the static squatting was practiced, 8-10 weeks postoperatively, the passive flexion was 120-130 degrees, 10-12 weeks postoperatively, the gradual passive flexion was the same as that of the healthy side, the sitting position was the same as the resistance knee extension exercise, 3-6 months postoperatively: the active flexion was the same as that of the healthy side, the lower step exercise, the full squatting of the supporting objects, and the physical exercise could be recovered gradually over 7 months postoperatively.
Assessment methods
The analysis of IKDC score [12], Lysholm score [13] and Tegner score [14] was performed in both group A and group B 6 hours before operation and 24 months after operation respectively. KT2000 [15] was also conducted to determine the degree of tibial retroversion preoperative and post-operative (24 months). AOFAS score [16] and Maryland score [17] were conducted on the affected limbs 1 day preoperative and 24 months of post-operative to analyze the differences of ankle function.
Statistical analysis
Statistical Product and Service Solutions (SPSS) 17.0 software (SPSS Inc., Chicago, IL, USA) was performed for statistical analysis. The normal distribution data were expressed as (mean±SD) (x̅±s). Student t-test was used for comparison between the two groups, and paired t-test was used for comparison before and after operation.