[Effectiveness of multidirectionally three-dimensional steel wire ring sleeve fixation in treatment of inferior patellar pole avulsion fractures].

Objective: To explore the method and effectiveness of multidirectionally three-dimensional steel wire ring sleeve fixation in the treatment of inferior patellar pole avulsion fractures.

Methods: Betweern January 2015 and January 2019, 22 patients with inferior patellar pole avulsion fractures were admitted and treated. There were 12 males and 10 females. The age ranged from 20 to 69 years, with an average age of 39.4 years. The causes of injury included 9 cases of traffic accident and 13 cases of falling. All of them were unilateral closed injury of knee joint, including 7 cases of skin contusion around patella. Preoperative range of motion of the affected knee was (20.82±7.16)° (range, 10°-35°). The time from injury to operation ranged from 3 to 12 days, with an average of 5.9 days. During the operation, the inferior patellar avulsion fracture was reduced with forceps; the patella was circumferentially ligated through the distal bone surface of the fracture with 0.8 mm diameter steel wire; then 3 longitudinal bone tunnels were made in the upper patella, respectively. The 0.8 mm diameter steel wire passed through the bone tunnel, and the longitudinal ring was attached to the ring to fix the upper and inferior patellar fracture. Tighten the transverse and longitudinal rings with No.2 tendon suture line, then longitudinally ringed and sutured to strengthen the patella. The knee range of motion, fracture healing time, and complications were recorded. The functional recovery of the knee joint was evaluated by Böstman score.

Results: All incisions healed by first intention, and no incision related complications occurred. All the 22 patients were followed up 13 months to 5 years with an average of 26.7 months. The fracture healing time was 9-12 weeks (mean, 10.9 weeks). At last follow-up, the knee range of motion was (129.77±2.35)° (range, 126°-135°), showing significant difference when compared with preoperative one ( =-67.022, =0.000). The Böstman score ranged from 31 to 36, with an average of 34.3. No reduction loss, fracture of steel wire, failure of internal fixation, and other complications occurred during follow-up.

Conclusion: Multidirectionally three-dimensional steel wire ring sleeve fixation in the treatment of inferior patellar pole avulsion fractures has the advantages of reliable fixation, early functional recovery, and fewer complications, so the effectiveness is satisfactory.