Abstract: Objective To evaluate the clinical efficacy of Hoffa fractures fixed by metal lag screws and absorbable screws under arthroscope. Methods 13 cases of Hoffa fracture were fixed by prizing reduction under arthroscopic surveillance. After satisfactory reduction, absorbable screw immersion was used to fix the load side, metal lag screw was used to reinforce the non-load side. At the same time, other injuries in the joint were repaired by I-stage. Adjustable brace fixation was performed after operation, and early non-load-bearing functional exercise was performed regularly. The degree of functional recovery of knee joint was recorded at follow up. Results All the patients were followed up for 8 to 24 months (average 13.6 months). All the incisions healed in one stage. There was no loosening or breakage of internal fixation and bone union occurred in the fracture. The average activity time is 9.4 weeks. According to the criteria of functional recovery after Hoffa fracture surgery, the functional recovery degree of knee joint was comprehensively assessed. 12 cases were excellent, and l cases was general curative effect, the excellent and good rate was 92.3%. Conclusions Under arthroscope, the using of metal lag screw combined with absorbable screw has the advantages of satisfactory reduction, minimal injury and firm fixation in the treatment of Hoffa fracture. It can be used to treat other intra-articular injuries in stage I, that can significantly reduce the stiffness of knee joint and improve the quality of life of patients.