Early Structural Results After Anatomic Triple Bundle Anterior Cruciate Ligament Reconstruction Validated by Tunnel Location, Graft Orientation, and Static Anteroposterior Tibia-Femur Relationship

Anatomical Triple Bundle Anterior Cruciate Ligament Reconstructions With Hamstring Tendon Autografts: Tunnel Locations and 2-Year Clinical Outcomes

PURPOSE

To anatomically clarify the location of the tunnel apertures created using the bony landmark strategy and to elucidate clinical outcomes after anatomic triple-bundle (ATB) anterior cruciate ligament (ACL) reconstruction.

METHODS

Thirty-two patients with unilateral ACL injury who had consented to undergo computed tomography (CT) at 3 weeks, as well as 2-year follow-up evaluation, were enrolled. At the time of surgery, remnant tissues were thoroughly cleared to create 2 femoral and 3 tibial tunnels inside the ACL attachment areas bordered by the bony landmarks. Two double-looped semitendinosus tendon autografts were prepared and fixed on the femur with two EndoButton-CLs and secured to the tibia with pullout sutures and plates with 10-20N of tension. The location of the tunnel aperture areas was assessed using 3-dimensional CT images, and 2-year postoperative clinical outcomes were evaluated.

RESULTS

The CT evaluation showed 100% of the femoral tunnel aperture area and at least 79% of the tibial tunnel aperture area were located inside the anatomic attachment areas. Thirty patients were available for clinical evaluation. The International Knee Documentation Committee subjective assessment showed all of the patients were classified as "normal" or "nearly normal." Lachman and pivot-shift tests were negative in 100% and 93%, respectively. The mean side-to-side difference of anterior laxity at the maximum manual force with a KT-1000 Knee Arthrometer was 0.7 ± 0.7 mm, ranging from 0 to 2 mm.

CONCLUSION

In ATB ACL reconstructions with hamstring tendon grafts, the tunnels can be created in proper locations using the arthroscopically-identifiable bony landmarks. Moreover, ATB ACL reconstruction with hamstring tendon grafts via the proper tunnels result in consistently satisfactory clinical outcomes.

LEVEL OF EVIDENCE

Level IV, case series.

Sagittal Inclination Angle of Graft Is Associated With Knee Stability After Anatomic Anterior Cruciate Ligament Reconstruction

PURPOSE

To evaluate whether the sagittal inclination angle (SIA) of a graft is associated with postoperative knee stability after anatomic anterior cruciate ligament (ACL) reconstruction.

METHODS

All patients who had undergone anatomic ACL reconstruction between April 2014 and September 2015 in addition to volunteers with no history of knee injury were eligible for inclusion in this study. The patients were evaluated by magnetic resonance imaging of the knee in full extension at 1 year after surgery, as were volunteers. The posterior tibial slope (PTS) angle and the SIA of the intact ACL and reconstructed graft were measured relative to each medial and lateral tibial plateau. The patients were examined for knee stability by the side-to-side difference in the anterior tibial translation on stress radiographs at minimum 2-year follow-up.

RESULTS

We included 43 patients (26 male, 17 female, mean age 32.8 ± 14.8 years) and 12 volunteers (7 male, 5 female, mean age 28.7 ± 3.1 years) as normal controls. The mean follow-up duration was 29.8 ± 3.6 months. The mean PTS angle and mean SIA in the patients did not significantly differ from those of the intact ACL. The PTS angle in the patients was not significantly correlated with postoperative side-to-side difference in the anterior tibial translation. However, the graft SIA was significantly correlated with the postoperative anterior tibial translation (medial SIA; r = 0.42, P = .005, lateral SIA; r = 0.52, P < .001).

CONCLUSIONS

Even if anatomically reconstructed, the graft SIA in reference to the tibial plateau at full knee extension is variable and is associated with postoperative knee stability. The larger graft SIA was correlated with graft laxity after anatomic ACL reconstruction.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Sequential analysis of three-dimensional tibiofemoral relationship through anatomic anterior cruciate ligament reconstruction with gravity-assisted radiographic technique in prone position

Background/objectives

It is important to restore the tibiofemoral relationship as well as the anterior knee laxity for more successful anterior cruciate ligament (ACL) reconstruction, since a residual abnormality in the tibiofemoral relationship would lead an abnormal stress on the articular cartilages/menisci and consequently increase the risk of osteoarthritis in the future. This study aimed to sequentially clarify the three-dimensional tibiofemoral relationship before and after anatomic anterior cruciate ligament (ACL) reconstruction under an anterior tibial load with a gravity-assisted radiographic technique in the prone position.

Methods

Fifteen patients with unilateral ACL injury participated in the study. Anatomic triple-bundle ACL reconstruction was performed using semitendinosus tendon autografts. During the computed tomography scans that were performed preoperatively, and those performed at 3 weeks and at 6 months postoperatively, the patients lay in the prone position with the knee flexed at 15°, wherein the calf weight could exert an anterior drawer force on the tibia due to gravity. Three-dimensional the tibial position relative to the femur were evaluated for each time point, followed by calculation of side-to-side differences in the parameters between the ACL-deficient/ACL-reconstructed knees and the contralateral intact knees. Seven healthy volunteers were enrolled in the control group and the side-to-side differences (right minus left) in these parameters were calculated.

Results

The tibia in the ACL-deficient knee was located anteriorly by 3.5 ± 1.1 mm and rotated internally by 2.4° ± 2.3°; these values were significantly larger than the corresponding values of −0.2 ± 1.5 mm and 0.1° ± 2.2° in the control group. However, at 3 weeks postoperatively, the tibia in the ACL-reconstructed knee was over-constrained as compared to that in the control group; it was located posteriorly by 2.5 ± 1.4 mm and rotated externally by 3.4° ± 3.4°. At 6 months postoperatively, no significant difference was observed in the tibial displacements/rotations between the patient and control groups. The side-to-side difference in the anterior knee laxity at the manual maximum anterior load was 0.1 ± 1.2 mm at 6 months postoperatively, with a significant improvement over the preoperative value of 7.4 ± 2.5 mm.

Conclusions

Anatomic ACL reconstruction could restore not only the normal anterior knee laxity, but also the normal tibiofemoral relationship even under an anterior tibial load.

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Tibiofemoral relationship was analyzed before and after anatomic ACL reconstruction.

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Tibial anterior shift and internal rotation was observed in ACL-injuried knees.

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Anatomic ACL reconstruction could restore the normal tibiofemoral relationship.

Editorial Commentary: Triple-Bundle Anterior Cruciate Ligament Reconstruction: More Is More or Less Is More?

We need ambitious pioneers to explore the frontiers of surgical technique, but the surgeons that follow are wise to wait for independent and robust evidence of clinical benefit. Double-bundle anterior cruciate ligament reconstruction has struggled to establish its role, and triple-bundle reconstruction is perhaps even less likely to gain widespread acceptance, given that cadaveric research has shown only a small biomechanical advantage over a double-bundle or even a single-bundle technique and there is no convincing evidence of improved clinical outcomes.

Editorial Commentary: Pursue the Anatomy of the Knee Anterior Cruciate Ligament Footprint

The paradigm of anterior cruciate ligament reconstruction has shifted from nonanatomic/isometric to anatomic reconstruction so as to mimic the native anterior cruciate ligament anatomy, as well as its function. A triple-bundle reconstruction technique more precisely mimics the native anterior cruciate ligament. On the other hand, functional advantages of triple-bundle reconstruction have not been fully elucidated. Comparative clinical studies between reconstruction techniques are needed.