ObjectiveTo summarize the prevention and treatment of iatrogenic medial collateral ligament (MCL) injuries in total knee arthroplasty (TKA).MethodsThe relevant literature about iatrogenic MCL injuries in TKA was summarized, and the symptoms, causes, preventions, and treatments were analyzed.ResultsPreventions on the iatrogenic MCL injuries in TKA is significantly promoted. With the occurrence of MCL injuries, the femoral avulsion can be fixed with the screw and washer or the suture anchors; the tibial avulsion can be treated with the suture anchors fixation, bone staples fixation, or conservative treatment; the mid-substance laceration can be repaired directly; the autologous quadriceps tendon, semitendinosus tendon, or artificial ligament can be used for the patients with poor tissue conditions or obvious residual gap between the ligament ends; the use of implant with greater constraint can be the last alternative method.ConclusionNo consensus has been reached to the management of iatrogenic MCL injuries in TKA. Different solutions and strategies can be integrated and adopted flexibly by surgeons according to the specific situation.
Objective To investigate whether the outlet of the femoral tunnel will cause iatrogenic injury to the medial collateral ligament (MCL) during posterior cruciate ligament reconstruction (PCLR) and estimate the safe angle of femoral tunnel placement. MethodsThirteen formaldehyde-soaked human knee joint specimens were used, 8 from men and 5 from women; the donors’ age ranged from 49 to 71 years, with an average of 61 years. First, the medial part of the femur was carefully dissected to clearly expose the region of the MCL course and attachment on the femoral medial aspect and to outline the anterior margin of the region with a marked line. The marked line divided the medial femoral condyle into an area with an MCL course and a bare bone area which is regarded relatively safe for no MCL course. Then, the posterior cruciate ligament (PCL) was cut to identify the femoral attachment of the PCL. After the knee joint was fixed at a 120° flexion angle, the process of femoral tunnel preparation for the PCL single-bundle reconstruction was simulated. The inside-out technique was used to drill the femoral tunnel from the PCL femoral footprint inside the knee joint with an orientation to exit the medial condyle of the femur, and the combination angle of the two planes, the axial plane and the coronal plane, was adapted to the process of drilling femoral tunnels at different orientations. The following 15 angle combinations were used in the study: 0°/30°, 0°/45°, 0°/60°, 15°/30°, 15°/45°, 15°/60°, 30°/30°, 30°/45°, 30°/60°, 45°/30°, 45°/45°, 45°/60°, 60°/30°, 60°/45°, 60°/60° (axial/coronal). The positional relationship between the femoral tunnel outlet on the femoral medial condyle and the marked line was used to verify whether the tunnel drilling angle was a risk factor for MCL injury or not, and whether the shortest distance between the femoral exit center and the marked line was affected by the various angle combinations. Furthermore, the safe orientation of the femoral tunnel placement would estimated. ResultsWhen creating the femoral tunnel for PCLR, there was a risk of damage to the MCL caused by the tunnel outlet, and the incidence was from 0 to 100%; when the drilling angle of the axial plane was 0° and 15°, the incidence of MCL damage was from 69.23% to 100%. There was a significant difference in the incidence of MCL damage among femoral tunnels of 15 angle combinations (χ2=148.195, P<0.001). By comparison between groups, it was found that when drilling femoral tunnels at 5 combinations of 45°/45°, 45°/60°, 60°/30°, 60°/45°, and 60°/60° (axial/coronal), the shortest distances between the tunnel exit and the marked line were significantly different than 0°/45°, 0°/60°, 15°/45°, 15°/60°, and 30°/30° (axial/coronal) (P<0.05). Additionally, after comparing the median of the shortest distance with other groups, the outlets generated by these 5 angles were farther from the marked line and the posterior MCL. ConclusionThe creation of the femoral tunnel in PCLR can cause iatrogenic MCL injury, and the risk is affected by the tunnel angle. To reduce the risk of iatrogenic injury, angle combinations of 45°/45°, 45°/60°, 60°/30°, 60°/45°, and 60°/60° (axial/coronal) are recommended for preparing the femoral tunnel in PCLR.