1.Study design
We started our prospective trial in 2016 and registered at http://www.chictr.org.cn/index.aspx(ChiCTR-OIC-16008306). We got the approved by the clinical research ethics committees. Each of the patient or otherwise their legal representative wrote the informed consent. Then we did the clinical trial in the West China hospital Sichuan University. This study followed the Good Clinical Practice guidelines and the guidelines of the Helsinki Declaration.
2.Criteria for including, excluding patients
Including criteria:
- Patients with knee dislocation
- PLC injury with two or more major ligaments (ACL, PCL, MCL, PMC) injured in knee joint shown by MRI
- Knee joint demonstrates obvious anterior/posterior and lateral/medial instability by physical examination
- No other severe physical injury that hinders limb functions
- Patients voluntarily agree to treatment protocol and are willing to cooperate in rehabilitation and follow-up examination
Excluding criteria:
- Patients with severe osteoarthritis
- Patients with combined complications which significantly hinders limb functions
- Patients that can’t be treated or can’t cooperate.
3.Participant
We recruited patients from 2016-2020 at the West China Hospital Sports Medicine Center. Specialized sports medicine surgeons identified patients in routine outpatient clinics. Aspects of evaluation include: history taking, physical examination, and imaging studies (x-ray, MRI). Through the aforementioned inclusion and exclusion criteria, the population of this study was finally determined. According to the diagnosis, the patients were divided into PLC injury group and PLC combined PMC injury group. Trained research associates approached eligible patients to explain the trial and to invite them to participate. All participants gave written informed consent.
4.Operation procedure
All operations are performed by two excellent surgeons. They lead all important steps in the surgery. There are no special requirements for surgical assistants.
PLC reconstruction:
Autologous hamstring tendon or peroneus longus tendon for PLC reconstruction surgery. The patient was placed in the supine position, the knee was flexed 90°, and the lateral epicondyle of the femur was taken as the turning point to make an incision on the lateral side of the knee joint. It runs proximally along the posterior border of the iliotibial band and distally to the plane of the fibular neck. Peel the flap forward and backward. From the inferior iliotibial band approach, the start point of the LCL and PT at the lateral femoral condyle is exposed medially, and the inferior border approach exposes the fibular start point of the LCL and the posterolateral ending point of the PT at the tibial plateau. A drill was used to establish bone tunnels at the LCL insertion of the lateral epicondyle of the femur, the LCL insertion of the fibula, and the posterolateral insertion of the PT tibial plateau. The tendon is first pulled into the fibular tunnel for compression fixation with absorbable screws. The tendon was then reflexed, and the reflex was introduced into the femoral tunnel, which was also squeezed with absorbable screws. Finally, the other end was introduced into the tibial tunnel, and compression fixation was performed under the condition of ensuring tension. Rinse the wound, suture the wound, and press the bandage. Figure 8a
PMC reconstruction:
The semitendinosus muscle was taken for PMC reconstruction. A longitudinal incision was made on the medial side of the knee joint, and a free flap was used to expose the start and ending point of the PMC: the lateral aspect of the medial condyle of the tibia and the lateral aspect of the medial femoral condyle. The establishment of the bone tunnel is carried out with a drill at the starting and ending points. Measure with the tendon so that the length of the tendon is slightly longer than the length between the two bone tunnels. Both ends of the tendon were introduced into the bone tunnel, and absorbable screws were used to slightly secure the tendon at the entrance of the bone tunnel. Tighten the screw with the knee flexed at 30° and under varus stress. The rest of the structure like POL is tightened and sutured on the outside with absorbable sutures or Transosseous suture. Rinse the wound, suture the wound, and press the bandage. figure 8b. In the acute stage of PMC injury, when the MCL has not contracted or absorbed, anchor fixation and Transosseous suture are used to repair the MCL.
Preoperative treatment:
Postoperatively, a gradual rehabilitation principle of immobilization first, passive later, and active activity is adopted. Within two weeks after the operation, the affected limb was fixed with a brace in the knee extension position of 0°, and the straight leg raising and quadriceps active contraction training were performed. After 2 weeks, gradually start knee bending training. Gradually open brace restriction to activity after 4 weeks Continue strength and range of motion exercises after 8 weeks. At 3 months, he was removed from the brace and crutches, started low-intensity aerobic training, and gradually returned to normal activities.
Outcome:
Follow-up was performed at 1, 3, 6, 9, and 12 months after surgery. We used pain visual analog scale (VAS)for pain, IKDC score, Lysholm score, Tegner score. Opti-knee (a portable motion analysis system) was used to evaluate the stability of knee joint at one year.
VAS is often used to assess pain. We use a 0-10 visual scale, with 0 representing no pain and 10 representing severe pain. Patients describe their pain by selecting numbers within this range[19]. The IKDC Subjective Knee Evaluation Form is scored by summing the scores of the individual items then transforming the score on the scale from 0 to 100 (by dividing the sum by 87, the total maximum possible score) then multiplying by 100.The higher the score, the higher the level of function and the lower the level of symptoms[20]. The Lysholm scale has been validated as a patient-administered instrument to measure symptoms and function in patients with a variety of knee injuries. It measures the domains of symptoms and complaints and functioning in daily activities slightly. This scale consists of eight items. It is scored on a scale of 0 to 100, with higher scores indicating fewer symptoms and higher levels of functioning[21]. The Tegner score scores a person's activity level between 0 and 10 where 0 is 'on sick leave/disability' and 10 is 'participation in competitive sports such as soccer at a national or international elite level'[22]. Opti-Knee (Innomotion Inc, Shanghai), was developed to track and analyze the 6DOF motion of the knee joint in a convenient and user-friendly clinical setup. A digitizer was used to calibrate patient-specific bone landmark points (i.e., great trochanter (GT), medial epicondyle (ME), lateral epicondyle (LE), medial tibia plateau (MP), lateral tibia plateau (LP), medial malleolus (MM), and lateral malleolus (LM)) with the participants in a neutral standing position. The neutral standing position was also used as a zero reference. Data about the positions of the marker sets was collected while the knee moved. The bony landmarks were calculated by the geometric relationship setup obtained from the initial position. 6DOF knee joint kinematics were calculated based on the local coordinate systems of the femur and the tibia using the bony landmarks. The averages and standard deviations of the knee kinematics from all gait cycles were calculated using an automated program[23].
Statistical analysis:
Continuous variables were expressed as mean ± standard deviation, and categorical variables were expressed as frequencies. The VAS, IKDC score, Lysholm score, and Tegner score were compared between the two groups at each follow-up time point before and after surgery using unpaired samples T test. The analysis tools that come with Opti-knee also generate mean ± standard deviation. Probability values with P less than 0.05 were considered significant. All statistical analyses were performed using SPSS 18.0.