Abstract:[Objective] To introduce the techniques and preliminary clinical results of surgical treatment and rapid rehabilitation of Hoffa fracture accompanied with medial collateral ligament avulsion fracture. [Methods] From May 2016 to March 2021, 3 patients re- ceived abovementioned treatment for the medial Hoffa fracture complicated with avulsion fracture at the origin of the medial collateral liga- ment. All the patients underwent open reduction and internal fixation with full-thread cannulated screws and medial plate through the medi- al incision. In addition, lag cannulated screws was used to fix the insertion of the medial collateral ligament with reinforcement by Ethicon suture. After operation, the knee was placed at 110°~120° of flexion, while analgesic pump used for pain relief and ankle pump exercise and quadriceps isometric contraction training were performed. Twenty-four hours later, knee extension-flexion exercise was performed 3 times a day with 30 minutes each time. After exercise, the knee joint was fixed at 110°~120° for a total of 3 days. After 3 days, the knee po- sition was determined according to the knee extension-flexion function. [Results] All the 3 patients had operation performed successfully without serious complications, such as vascular and nerve injury, and got incisions healed well. The knee extension-flexion range of motion (ROM) was of (142.3±8.7)° at 2 months after operation, whereas the HSS score was of (85.4±5.1) at the latest follow-up. All the patients had knee function recovered well without knee stiffness, while got fractures healed well on the radiographs with healing time of 3~6 months., whereas no adverse imaging changes such as internal fixation loosening and displacement, refracture of the repaired ligament occurred. [Conclusion] After open reduction and internal fixation of Hoffa fracture complicated with avulsion fracture of medial collateral ligament, maintaining 110°~120° knee flexion fixation and early functional exercise do accelerate the rehabilitation of knee function and reduce the occurrence of complications.