Does Remnant Preservation Influence Tibial Tunnel Enlargement or Graft-to-Bone Integration After Double-Bundle Anterior Cruciate Ligament Reconstruction Using Hamstring Autografts and Suspensory Fixation? A Computed Tomography and Magnetic Resonance Imaging Evaluation

Less tunnel enlargement in triple-bundle versus double-bundle anterior cruciate ligament reconstruction: A randomized clinical trial

BACKGROUND

No study thus far has compared tunnel enlargement between double-bundle and triple-bundle anterior cruciate ligament reconstruction. We compared tibial tunnel enlargement and rate of tibial tunnel coalition between these two reconstructions, hypothesizing that tibial tunnel enlargement in triple-bundle reconstruction is less than that in double-bundle reconstruction, and that the tunnel coalition rate is equal between the two procedures.

METHODS

This prospective randomized clinical trial included 25 patients who underwent computed tomography 2 weeks and 1 year postoperatively. Eleven patients underwent double-bundle anterior cruciate ligament reconstruction and 14 underwent triple-bundle anterior cruciate ligament reconstruction. Tunnel positions and tunnel coalition at the tibial tunnel aperture were assessed using three-dimensional computed tomography. Tunnel enlargement rate was calculated by measuring the sagittal and axial widths of the tibial bone tunnel 10 mm from the tibial tunnel aperture. These parameters were then compared between the groups.

RESULTS

The changes in tunnel positions and tunnel coalitions between groups were not significantly different. On both sagittal and axial views, the tunnel enlargement rates of the medial and lateral sections of the anteromedial bundle in the triple-bundle group were significantly smaller than those in the double-bundle group (sagittal view, p = 0.02 and < 0.01, respectively; axial view, p = 0.02 and ≤ 0.05, respectively). The groups did not differ significantly in terms of posterolateral tunnel enlargement.

CONCLUSION

Tunnel widening in the medial and lateral sections of the anteromedial bundle-associated tibial tunnel in triple-bundle anterior cruciate ligament reconstruction was smaller than that of double-bundle reconstruction. The tunnel coalition rates between the two reconstructions were not significantly different.

Morphological Changes in the Tibial Tunnel After ACL Reconstruction With the Outside-In Technique and Adjustable Suspensory Fixation

Background

Anterior cruciate ligament reconstruction (ACLR) using the complete tibial tunnel technique and adjustable-loop cortical suspensory fixation is known to leave a "dead space" that holds the loop device in the tibial tunnel. The consequence of the dead space and its effect on graft healing are still uncertain.

Purpose

To investigate morphological changes in the tibial tunnel and their effect on graft healing, and to identify factors affecting bone healing in the tibial loop tunnel after ACLR with a quadrupled semitendinosus tendon autograft using adjustable suspensory fixation.

Study Design

Case series; Level of evidence, 4.

Methods

Included were 48 patients (34 male, 14 female; mean age, 25.2 ± 5.6 years) who underwent ACLR with a quadrupled semitendinosus tendon autograft using adjustable suspensory fixation. To evaluate tibial tunnel morphology, computed tomography was performed at 1 day and 6 months postoperatively. At 1 year postoperatively, graft healing was assessed on magnetic resonance imaging using the graft signal-to-noise quotient (SNQ). Multivariate regression and correlation analyses were performed to determine any associations between volumetric changes in bone healing and operative variables.

Results

At 6 months after ACLR, a mean of 63.2% of the tibial loop tunnel was filled by bone. Multivariate regression analysis showed that remnant preservation was significantly associated with the loop tunnel filling rate (P < .001). At 1 year after ACLR, the tibial loop tunnel was almost completely closed (98.5%). There were no correlations between loop tunnel volume and graft integration or graft SNQ. A significant but weak correlation was found between graft tunnel volume and intratunnel graft SNQ (P = .10) as well as integration grade in the tibial tunnel (P = .30).

Conclusion

Excellent bone filling in the tibial loop tunnel was seen at 1 year after ACLR. Remnant preservation was significantly associated with the loop tunnel filling rate. A weak correlation was found between graft tunnel volume and intratunnel graft SNQ as well as integration grade in the tibial tunnel.

The incidence of tibial tunnel coalition is higher than femoral tunnel coalition in double-bundle anterior cruciate ligament reconstruction using hamstring autografts: A systematic review

INTRODUCTION

Intra-operative and postoperative coalition of tunnels may occur in double-bundle (DB) anterior cruciate ligament reconstruction (ACLR). However, the incidence and effect on clinical outcomes of tunnel coalition following primary DB ACLR using a hamstring autograft has yet be analyzed, and thus remains unknown. The objective of this systematic review was to identify the incidence of tunnel coalition upon DB ACLR using hamstring autografts and to elucidate any clinical outcomes and/or complications that tunnel coalition may have postoperatively.

HYPOTHESIS

The incidence of tunnel coalition would increase in respect to time from the index surgery, and that tunnel coalition would be related to poorer clinical outcomes compared to non-coalition cases.

METHODS

Three databases (PubMed, EMBASE, Cochrane Library) were searched in accordance with PRISMA and R-AMSTAR guidelines on June 15, 2020. Relevant studies were screened in duplicate and data regarding patient demographics, incidence of femoral and tibial tunnel coalition, and outcomes were extracted. Coalition rate was also compared between follow up at 1 month or less defined as "shorter-term", and 6 months or greater as "longer-term". Coalition is defined as the missing of a bony bridge between the two tunnels.

RESULTS

Thirty-six studies examining 1,574 patients, mean age 29.1 years, were included in this study. 29 studies (1,110 knees) reported the incidence of femoral coalition with a pooled rate of coalition of 8% (95% CI=4-12%). 28 studies (1,129 knees) reported an incidence of tibial coalition with a pooled rate of coalition of 21% (95% CI=13-30%). The incidence of tibial coalition was significantly higher than the incidence of femoral coalition across 21 comparative studies (OR=3.37, 95% CI=1.41-8.09, p=0.0065). Only two studies (111 knees) compared tunnel coalition and non-coalition groups for clinical outcome and no significant differences were observed with regards to Lysholm score, Tegner activity scale, and knee laxity measured with a KT-1000 arthrometer.

DISCUSSION

The rate of tibial tunnel coalition in DB ACLR is higher than femoral tunnel coalition, particularly at longer-term follow-up. Despite the higher radiographic evidence of coalition, the clinical effects of such remain to be ascertained, and further comparative studies are required to facilitate this understanding.

LEVEL OF EVIDENCE

IV, systematic review.

Remnant-Preserved Single-Bundle Anterior Cruciate Ligament Augmentation in Multi-ligamentous Knee Reconstruction

This study was conducted to present remnant-preserving anterior cruciate ligament (ACL) augmentation as a useful option for partial ACL injury in multiligament knee injury (MLKI) cases, which may also contribute to conserving graft resources. The present study involved patients diagnosed with MLKI at our institute from Spring 2006 to February 2021. A total of 71 MLKI cases were provided surgery due to knee instability and disability. For every patient, an arthroscopic diagnostic was performed to ensure that ACL tear and a remnant were present. When the ACL remnant was classified into group 2, 3, or 4 of Nakamae's classification, remnant-preserved single bundle ACL augmentation was performed. Graft selection and the combination of injured ligaments were evaluated. The side-to-side difference under an anterior tibial load of 134 N with an arthrometer and the leg symmetry index at 60 degrees/s were measured. The present procedure was performed for five cases (male/female: 4/1, mean age: 33.6 years). The mean follow-up period was 26.4 months. The combination of torn ligaments was as follows: 3 cases of ACL + medial collateral ligament, one case of ACL + posterior cruciate ligament, and one case of ACL + posterolateral corner. An ACL augmentation graft was performed using an ipsilateral gracilis tendon in 2 cases, a contralateral full semitendinosus tendon in 2 cases, and the ipsilateral distal 1/2 of the semitendinosus tendon in 1 case. The mean side-to-side difference was 1.07 ± 0.4 mm. The mean leg symmetry index was 82.6 ± 12.2% in knee extension and 96.3 ± 9.9% in knee flexion. Although the present study was a small case series, the remnant-preserved single-bundle ACL augmentation for MLKI surgery provided good clinical outcome and conserved the graft resource. Even in the MLKI case, this technique is one of the useful surgical options. The level of evidence of this study is level IV (case series).

A new remnant preservation technique reduces bone tunnel enlargement after anatomic double-bundle anterior cruciate ligament reconstruction

PURPOSE

To investigate the effect of a new remnant preservation technique with a focus on remnant continuity on postoperative femoral and tibial tunnel enlargement after anatomical double-bundle anterior cruciate ligament reconstruction (ACLR).

METHODS

A total of 150 knees were divided into three groups: Preservation Group (Group P: 49 knees), wherein the remnant continuity remained after tunnel creation; Resection Group (Group R: 47 knees), wherein the remaining remnant was resected, and Absent Group (Group A: 54 knees), wherein the remnant had no femoral attachment before tunnel creation. In Group P, the remnant maintained continuity, and the anteromedial (AM) and posterolateral (PL) bundles were positioned anterior and posterior to the remnant, respectively. Computed tomographic scans were performed at 1 week and 1 year after surgery, and the cross-sectional area of each tunnel aperture was measured. Tunnel enlargement was compared among the three groups by one-way analysis of variance (ANOVA) and the Bonferroni test. Univariate and multivariate logistic analyses were performed to identify the risk factors for tunnel enlargement in demographic and radiographic data.

RESULT

For femoral AM tunnels, the tunnel enlargement of Group P was significantly smaller than Groups R and A (p < 0.001), femoral PL (p < 0.001 vs. R and A), tibial AM (p < 0.001 vs. R, 0.002 vs. A), and tibial PL (p < 0.001 vs. R, 0.002 vs. A). There was no significant difference between Groups R and A. Multivariate logistic analysis showed that remnant preservation was a significant factor in reducing tunnel enlargement in the femoral AM, femoral PL, tibial AM, and tibial PL.

CONCLUSION

The new remnant-preserving anatomical double-bundle ACLR, which preserves the continuity of the remnant, prevented all bone tunnel enlargement at 1 year postoperatively.

LEVEL OF EVIDENCE

Level III.

Hybrid Remnant-Sparing Anterior Cruciate Ligament Repair-Reconstruction

In anterior cruciate ligament (ACL) reconstruction, the remnant ACL is often debrided in an effort to improve visualization of patient anatomy and reduce surgical difficulty. However, retention of the tibial remnant of a torn ACL theoretically portends several advantages. These include preservation of knee proprioception and mechanoreceptors, an enhanced biological environment for healing, and accelerated revascularization and ligamentization of the graft. Despite these advantages, it is not a widely adopted practice and the optimal technique is still subject to debate. The purpose of this technical note is to describe our preferred technique for performing hybrid ACL reconstruction with remnant incorporation.

Remnant preservation does not affect accuracy of tibial tunnel positioning in single-bundle ACL reconstruction

PURPOSE

Remnant preservation, in anterior cruciate ligament (ACL) reconstruction, has potential biological advantages. However, graft positioning remains vital to functional outcome and the prevention of failure. The aim of this study was to investigate the accuracy and precision of tibial tunnel positioning in remnant preservation single-bundle hamstring reconstruction.

METHODS

Fifty consecutive adult patients, with isolated ACL rupture, were recruited to a prospective study. Remnant preservation was performed in all cases where > 25% of the native ACL was present. Three-dimensional computer tomography was preformed 3-6 months post-operatively to assess tibial tunnel position (using a grid-based measurement). Accuracy and precision of this technique were assessed against published anatomical data in direct comparison with the group where remnant preservation could not be performed.

RESULTS

Two patients withdrew following surgery. In the remaining groups (31 remnant preservation; 17 non-remnant preservation), no difference was demonstrated in tunnel position (40.4 ± 6.7% (anterior-to-posterior) and 47.4 ± 1.5% (medial-to-lateral) vs. 38.8 ± 4.9% and 46.7 ± 1.5%, respectively; n.s.), accuracy (6.1% vs. 4.8%; n.s.) or precision (3.9% vs. 2.8%; n.s.).

CONCLUSIONS

Remnant preservation can be safely performed without compromising tunnel position. Therefore, the potential benefits of this technique can be utilised, in clinical practice, without sacrificing the ability to optimize tibial tunnel positioning.

LEVEL OF EVIDENCE

III.

Anatomical Arthroscopic Anterior Talofibular Ligament Repair and Reconstruction Using a Free Tendon

Arthroscopic techniques for anterior talofibular ligament (ATFL) repair and reconstruction have been developed in recent years. We simultaneously performed anatomical arthroscopic ATFL repair and reconstruction using a free tendon graft. The ATFL remnant is carefully dissected only at the footprint of the superior limb of the ATFL, and a bone tunnel is created on each side of the fibula and talus. A soft suture anchor with 2 sets of threads is inserted into the fibular tunnel. One set of threads is used to grab the ATFL remnant via a lasso-loop technique, whereas the other set of threads is used to introduce the ATFL graft. The graft is first fixed with a screw in the talar tunnel. Subsequently, the ATFL remnant and the graft are tightened simultaneously by pulling the 2 sets of suture anchor threads at the fibular tunnel and are fixed with a screw. This technique provides the possible advantages of remnant preservation and promotion of load sharing by the repaired ATFL remnant and the reconstructed ATFL graft.