Open screw fixation versus arthroscopic suture fixation of tibial posterior cruciate ligament avulsion injuries: a mechanical comparison.

PURPOSE: The objective of this study was to compare an arthroscopic suture technique with an open posterior screw fixation technique, by use of mechanical testing, for the treatment of posterior cruciate ligament (PCL) tibial bony avulsion.

METHODS

We split 10 intact human cadaveric knee pairs (20 knees) into 2 groups (A and B) with 1 knee from each pair and mounted them in a conventional tensile tester (Kratos 5002 Universal Biomechanical Test Machine; Kratos Dynamômetros, São Paulo, Brazil). By applying a posterior tibial load up to 100 N at 90 degrees of flexion, tibial displacement and stiffness were recorded. After a simulated PCL tibial avulsion fracture, the knees underwent PCL reattachment, with open screw fixation in group A and arthroscopic suture fixation in group B. The tests were performed first on intact and then on injured and operated knees. A direct visual inspection was performed postoperatively on all operated knees after a posterior arthrotomy to verify the fixation integrity.

RESULTS

One knee in each group had a fixation failure on visual inspection. Analysis of variance testing showed no differences between groups A and B for tibial posterior displacement (P = .229) and stiffness (P = .285) analysis.

CONCLUSIONS

The arthroscopic PCL tibial avulsion suture technique that we present is as reliable as open screw fixation for this lesion in terms of initial fixation.

CLINICAL RELEVANCE: Various PCL avulsion surgery techniques have been reported, including alternatives to avoid potentially injurious exposure of the popliteal fossa. Following on this research line, we present a new arthroscopic suture for the treatment of this lesion that requires no special surgical skill or materials.