Title:
Revision posterior cruciate ligament reconstruction using a modified tibial-inlay double-bundle technique.

Abstract:
Revision of an unsuccessful posterior cruciate ligament (PCL) reconstruction is a complicated clinical procedure with an outcome that may be less satisfactory than that after a typical primary PCL reconstruction. The purpose of this study was to evaluate the reasons for failure of primary PCL reconstructions and to determine the clinical outcomes of revision PCL reconstruction after a minimum of two years of follow-up.
Twenty-eight revision PCL reconstructions were performed by a single surgeon. Four cases that involved diverse operative procedures and two cases with a duration of follow-up of less than twenty-four months were excluded; the outcomes of the remaining twenty-two reconstructions were analyzed at the time of the latest follow-up (at least twenty-four months postoperatively). A technique involving a double femoral tunnel, a modified tibial inlay, and Achilles tendon allograft was used in all twenty-two of these revision reconstructions. Seventeen patients (77%) underwent concomitant reconstruction of posterolateral corner structures. Knee stability was measured with use of posterior stress radiography as well as with a maximum manual displacement test utilizing a KT1000 arthrometer. The subjective International Knee Documentation Committee (IKDC) and objective Orthopädische Arbeitsgruppe Knie (OAK) scoring systems were used to evaluate the clinical outcome.
Nine (41%) of the primary PCL reconstructions most likely failed because of a single factor and thirteen (59%) most likely failed because of multiple factors. The most common probable causes of failure were posterolateral rotatory instability (seventeen knees, 77%) and improper graft tunnel placement (nine knees, 41%). Side-to-side differences during posterior stress radiography improved from 9.9 ± 2.8 mm preoperatively to 2.8 ± 1.8 mm at the time of the latest follow-up (p < 0.001). The subjective and objective clinical scores at the latest follow-up evaluation were significantly better than the preoperative scores (p < 0.001).
Arthroscopic revision PCL reconstruction with use of the modified tibial-inlay double-bundle technique improved knee stability, as measured with posterior stress radiography and clinically, and outcomes. Associated posterolateral rotatory instability should be surgically corrected during PCL reconstruction to prevent graft failure resulting from abnormal opening of the lateral aspect of the tibiofemoral joint.