Summary

Generalized joint laxity and/or hyperextended knee (GJL and/or HK) affect ligamentization of the grafts and clinical outcomes after anatomic double-bundle ACL reconstruction. GJL and/or HK was placed in L group, while the other group was placed in N group, There was no significant difference between the two groups in AMB, however it was significantly poorer ligamentization in PLB in L group

Abstract

Purpose

There are many factors—such as the surgical techniques used, rehabilitation protocol, and structural and physiologic characteristics of the patients—that contribute to success after anterior cruciate ligament (ACL) reconstruction. Recent studies have suggested generalized joint laxity (GJL) and/or hyperextended knees (HK) as risk factors for graft failure after ACL reconstruction. The aim of this study was to investigate whether GJL and/or HK affect ligamentization of the grafts and clinical outcomes after anatomic double-bundle (AD) ACL reconstruction.

Materials And Methods

One hundred twenty-six patients (mean age 20.6 ± 9.3 years) underwent ADACL reconstruction using semitendinosus tendon autografts. All operations were performed by one experienced surgeon. These patients consented to remove the post screw that fixed the grafts onto the tibia and to a second-look arthroscopic examination. The mean follow-up period after ACL reconstruction was 14.8 ± 3.6 months. Patients were divided into two groups. One patient group that had GJL and/or HK was placed in the laxity group (L group, n = 35), while the other group was placed in the normal group (N group, n = 91). The focus of the second-look arthroscopy was on graft thickness, apparent tension, and synovium coverage of the anteromedial bundle (AMB) and the posterolateral bundle (PLB) graft. Each bundle was evaluated as excellent, fair, or poor according to Hokkaido university classification. Functional evaluations involved instrument-measured side-to-side difference of anterior laxity (KS), peak isokinetic (60°/s) and isometric (80° of flexion) torque of the quadriceps and hamstrings, and one-leg hop test and heel-height difference (HHD). Subjective evaluations included the International Knee Documentation Committee (IKDC) subjective score and Lysholm score.

Results

The second-look arthroscopic evaluation of the AMB graft revealed no significant difference between each group (P = 0.26). However, the PLB graft showed an excellent rating in 62.9%, a fair in 25.7%, and a poor in 11.4% of the L group; it also showed an excellent rating in 82.4%, a fair in 17.6%, and a poor in 0% of the N group. The L group (P < 0.01) showed statistically significant results. There was no significant difference between the two groups in KS (P = 0.74), mean peak isokinetic torque (quadriceps: P = 0.56, hamstrings: P = 0.44), isometric torque (quadriceps: P = 0.80, hamstrings: P = 0.52) torque, HHD (P = 0.49), one-leg hop test (P = 0.29), the IKDC subjective score (P = 0.31) or Lysholm score (P = 0.48).

Conclusion

Our study showed poor ligamentization of the PLB after ADACL reconstruction due to GJL and/or HK. In the case with GJL and/or HK, rehabilitation management and the selection of surgical procedure may lead to more success graft ligamantization.