Fixation of delayed union or non-union posterior cruciate ligament avulsion fractures.

PURPOSE To report the outcome of fixation for delayed union or non-union posterior cruciate ligament (PCL) avulsion fractures. METHODS Seven men and 4 women aged 24 to 35 (mean, 28) years underwent lag screw or suture fixation for non-union or delayed union of avulsion fracture of PCL tibial attachment after a mean delay of 8.6 (range, 4-14) months. Patient satisfaction was assessed using a visual analogue scale (VAS). Functional outcome was evaluated using the Lysholm scale. RESULTS The mean follow-up period was 17 (range, 8-36) months. The mean Lysholm score improved from 82 preoperatively to 92 at the final follow-up (p=0.34), the mean range of knee motion improved from 82º to 87º (p=0.008), and the mean VAS score for patient satisfaction improved from 4.3 to 7.4 (p=0.0004). All patients but one achieved bone union after a mean of 7.5 (range, 7-9) weeks. Functional outcome was excellent for 6 patients, good for 4, and fair for one. Posterior drawer test was positive (grade I laxity) in 3 patients whose outcome was good for 2 and fair for one. The latter had non-union after Ethibond suture repair for a communited fracture. There were no instances of wound complications or implant loosening. CONCLUSION Fixation with lag screw or suture combined with bone grafting for delayed union or non-union of PCL avulsion fractures achieves acceptable functional outcome.