To evaluate the clinical effect of anchor suture on anterior MCL anterior bundle avulsion and knee instability during TKA operation.

A retrospective analysis of 3 922 patients who received TKA in the Department of Orthopaedics, Department of Orthopedics, Dongguan Hospital from January 2011 to December 2017 was performed, and 48 cases (1.2%) of MCL anterior bundle avulsion and knee instability were determined during operation All the patients underwent anchor suture. All the patients used hinged knee braces within six weeks after surgery. At each follow-up visit, the range of motion of the knee joint was measured. X-ray examination was performed at six weeks, three months, and one year after the surgery (then once a year) to evaluate the HSS knee score. The results were analyzed by t test.

In 3 922 cases of total knee arthroplasty, 48 cases (1.2%) had intraoperative MCL injury. Among them, one patient died within two years after the operation, two patients were lost for follow-up. A total of 45 patients were included. Among them, MCLs of 24 cases were torn, and MCLs of 21 cases were broken. Thirty-five cases occurred in TKA with cruciate ligament retention and 10 cases occurred in post-stable TKA. At the last follow-up, the maximum knee flexion (111.2±18.8) °, maximum knee extension (1.5±1.5) °, and range of motion (110.2±30.2) ° were all significantly higher than those before the treatment [ (107.5±22.5) °, (5.5±4.5) °, (102.2±27.8) °] (t =2.822, 5.026, 3.670, all P <0.05). The average follow-up time was (99.2±5.7) months. None of the patient had knee instability. Five patients received intervention for stiff knees (four manual manipulations and one revision), and two patients received revision for aseptic loosening of the artificial knee.

MCL anterior bundle avulsion can be repaired and treated by anchor suture during TKA, and then hinged knee brace is applied. Knee stiffness is a common complication.