ObjectiveTo analyze the importance and effectiveness of Tillaux bone block in Ruedi-Allgower type Ⅲ of Pilon fracture surgery.MethodsTwenty-one patients with Pilon fractures with Tillaux dislocation were treated between February 2010 and September 2013. There were 17 males and 4 females, aged from 28 to 68 years with an average age of 42.9 years. The causes of injury included falling from height in 13 cases, falls injury in 4 cases, crush injury in 2 cases, and sprained injury in 2 cases. X-ray film and CT examination showed that all 21 patients had fibula fracture and Tillaux bone block had obvious displacement. According to AO/OTA classification, there were 3 cases of type C1.2, 1 case of type C1.3, 10 cases of type C2, and 7 cases of type C3. The duration from injury to operation ranged from 4 to 31 days, with an average of 10 days. All cases of Pilon fracture were treated with open reduction and plate internal fixation. Steel plate or screw was used to fixation for Tillaux block; allograft bone graft was selected for compression of fracture.ResultsThere were 2 cases of skin necrosis at the corner of wound after operation, and the wound healed after corresponding treatment; the wound healed at first intention in the other 19 cases. The effect of surgical reduction was evaluated by Burwell-Chamley imaging scoring system within 72 hours after operation, there were 19 cases of anatomical reduction and 2 cases of general reduction. All the 21 patients were followed up 18-48 months, with an average of 24.9 months. No complication such as nerve injury, loosening of internal fixation, or periprosthetic fracture was found during follow-up. All fractures obtained bone healing, which lasted from 4 to 8 months, with an average of 6 months. The ankle and hindfoot scores of the American Orthopaedic Foot and Ankle Society (AOFAS) were used to evaluate the ankle and hindfoot function at 1 year after operation or at last follow-up, the results were excellent in 13 cases, good in 6 cases, and fair in 2 cases, with an excellent and good rate of 90.5%. Internal fixator was removed from 19 patients at 15-19 months after operation. There were 17 cases of joint hyperplasia and 4 cases of osteoarthritis. All joint mobility was restored. The functional recovery of the ankle joint was evaluated according to the Olerud-Molander ankle fracture score standard, the results were good in 6 cases, fair in 8 cases, and poor in 7 cases at postoperative full weight training; and after 1 year of full weight training, the results were excellent in 10 cases, good in 3 cases, fair in 6 cases, and poor in 2 cases.ConclusionThe Tillaux bone block is a reliable marker for the reduction of complex Pilon fractures. The reconstruction of the Tillaux can improve the effectiveness of complex Pilon fractures.