Comparison of tibial inlay versus transtibial techniques for isolated posterior cruciate ligament reconstruction: minimum 2-year follow-up

Abstract

Purpose: Surgical treatment of isolated posterior cruciate ligament (PCL) injuries is controversial. The purpose of this retrospective study was to evaluate the surgical outcomes of PCL reconstruction. Two techniques were compared, the traditional endoscopic and the more recent tibial inlay, to determine if the inlay technique yielded more stable reconstructions.

Type of study: Retrospective study of surgical outcomes.

Methods: Between 1980 and 1997 [corrected], 29 patients underwent surgery for isolated PCL injuries at our institution. Two patients underwent primary repair, 4 underwent primary repair with semitendinosus-gracilis augmentation, and 1 had a tibial inlay with a double femoral tunnel, and these patients were excluded from this study. Two patients were lost to follow-up, leaving 20 patients who were evaluated at a mean follow-up of 5.7 years (range, 2 to 15 years). The average age at surgery was 29 years (range, 17 to 49 years). The primary indication for surgery was instability (95%). The surgical procedures included 13 traditional endoscopic transtibial PCL reconstructions (9 bone-patellar tendon-bone [BPTB] autograft, 2 BPTB allograft, and 2 allograft Achilles tendon) and 7 tibial inlay (all BPTB, 5 allograft and 2 autograft). Each patient was evaluated using the Tegner, Lysholm, and American Academy of Orthopaedic Surgeons (AAOS) knee-rating scales, physical examination, corrected KT-1000 arthrometry, functional testing, and radiographs. Statistical analysis was performed using the Fisher exact t test, Wilcoxon signed-ranks test, and Mann-Whitney test.

Results: Overall, 90% pf patients were satisfied with their surgery. The postoperative posterior drawer test result improved in 4 of 7 (57%) in the inlay group, and in 5 of 13 (38%) in the endoscopic group. The mean corrected KT-1000 measurement was 5.7 mm overall, 5.5 mm (inlay) and 5.9 mm (endoscopic). The mean preoperative Tegner score was 6.86 (inlay) and 6.92 (endoscopic). The mean postoperative Tegner score was 6.00 for both groups. The mean Lysholm score was 76 (inlay) and 82 (endoscopic), and the AAOS knee score was 77 (inlay) and 90 (endoscopic). There was a trend toward increased radiographic progression of Fairbanks changes in the medial and patellofemoral compartments in the endoscopic group, but the numbers did not reach statistical significance (P = .057).

Conclusions: When comparing the traditional endoscopic reconstructions with the tibial inlay technique, there were no significant differences in posterior drawer testing, KT-1000, functional testing, or Lysholm, Tegner, and AAOS knee scores at a minimum 2 year follow-up.

Clinical relevance: The results of this study indicate that neither method (transtibial or inlay) of PCL reconstruction consistently restores anteroposterior stability to its original state when using a single-bundle femoral attachment site.