Does Second-Generation Suspensory Implant Negate Tunnel Widening of First-Generation Implant Following Anterior Cruciate Ligament Reconstruction?

Adjustable-Loop Cortical Suspensory Fixation Results in Greater Tibial Tunnel Widening Compared to Interference Screw Fixation in Primary Anterior Cruciate Ligament Reconstruction

Background: Although the use of adjustable-loop suspensory fixation has increased in recent years, the influence of the shortcomings of suspensory fixation, such as the bungee-cord or windshield-wiper effects, on tunnel widening remains to be clarified. Hypothesis/Purpose: The purpose of this study was to compare adjustable-loop femoral cortical suspensory fixation and interference screw fixation in terms of tunnel widening and clinical outcomes after anterior cruciate ligament reconstruction (ACLR). We hypothesized that tunnel widening in the adjustable-loop femoral cortical suspensory fixation (AL) group would be comparable to that in the interference screw fixation (IF) group. Methods: This study evaluated patients who underwent primary ACLR at our institution between March 2015 and June 2019. The femoral and tibial tunnel diameters were measured using plain radiographs in the immediate postoperative period and 2 years after ACLR. Tunnel widening and clinical outcomes (Lysholm score, 2000 International Knee Documentation Committee subjective score, and Tegner activity level) were compared between the two groups. Results: There were 48 patients (mean age, 29.8 ± 12.0 years) in the AL group and 44 patients (mean age, 26.0 ± 9.5 years) in the IF group. Tunnel widening was significantly greater in the AL group than that in the IF group at the tibia anteroposterior (AP) middle (2.03 mm vs. 1.32 mm, p = 0.017), tibia AP distal (1.52 mm vs. 0.84 mm, p = 0.012), tibia lateral proximal (1.85 mm vs. 1.00 mm, p = 0.001), tibia lateral middle (2.36 mm vs. 1.03 mm, p < 0.001), and tibia lateral distal (2.34 mm vs. 0.85 mm, p < 0.001) levels. There were no significant differences between the two groups with respect to femoral tunnel widening and clinical outcomes. Conclusions: Tibial tunnel widening was significantly greater in the AL group than in the IF group at 2 years after primary ACLR. However, the clinical outcomes in the two groups were comparable at 2 years.

A prospective randomized study of arthroscopic ACL reconstruction with adjustable- versus fixed-loop device for femoral side fixation

Purpose

Suspensory devices are extensively used in the management of anterior cruciate ligament (ACL) tear. They include fixed- and adjustable-loop devices. There are only a few studies comparing the efficacy of these two devices in the available literature. Therefore, the aim of this study is to compare clinical outcomes between the adjustable-loop device (group I) and fixed-loop device (group II).

Materials and methods

This was a prospective randomized study. Both groups were equivalent in demographic, preoperative, and intraoperative variables. Twenty-three patients underwent femoral side graft fixation with adjustable-loop and 20 with fixed-loop devices. Four patients were lost to follow-up. Assessment of clinical outcome was done with International Knee Documentation Committee (IKDC) score, Lysholm score, and knee stability tests (Lachman test and pivot shift test). Patient evaluation was performed preoperatively and finally postoperatively 2 years after surgery.

Results

Postoperative IKDC scores of group I and II were 91.9 ± 3.6 and 91.5 ± 3.6, respectively, and Lysholm scores were 91.0 ± 3.6 and 91.4 ± 3.5, respectively, after 2 years; however, the difference in the outcomes was statistically insignificant (p > 0.05). Twenty patients (87%) in group I and 17 patients (85%) in group II had a negative Lachman test (p = 0.8). Twenty-two patients (95.7%) in group I and 19 patients (95%) in group II had a negative pivot shift test (p = 0.9).

Conclusion

ACL reconstruction with fixed- and adjustable-loop suspensory devices for graft fixation gives equivalent and satisfactory clinical results.

Level of evidence

1.

Editorial Commentary: Call for a Better Femoral Fixation Device in Anterior Cruciate Ligament Reconstruction: Adjustable-Loop Fixation Appears Better in Theory Than in Reality

Femoral tunnel widening after anterior cruciate ligament reconstruction is a major complication that results in more complex revision surgery. One prevailing theory of the source of this widening is the "bungee cord effect" resulting from suture fixation within the femoral tunnel. Adjustable-loop fixation devices were proposed to theoretically correct this by reducing the amount of suture within the femoral tunnel. Review of the current literature reveals mixed outcomes with most data pointing to no difference between the adjustable and fixed devices, especially with regard to tunnel widening. Adjustable-loop devices are not currently meeting the theoretical expectations, and the quest for improved femoral fixation continues.