Remnants-preserving ACL reconstruction using direct tendinous graft fixation: a new rat model

Background Anterior cruciate ligament (ACL) repair techniques are new emerging strategies prevailing, in selected cases, over standard reconstruction of the ACL with excision of its remnants. Mid-substance ACL tears represent a challenge for ACL repair techniques, and remnants-preserving ACL reconstruction (rp-ACLR) using an autograft remains the recommended treatment in this situation. However, morbidity associated with the autograft harvesting prompts the need for alternative surgical strategies based on the use of synthetic scaffolds. Relevant small animal models of mid-substance tears with ACL remnants preservation and reconstruction are necessary to establish the preliminary proof of concept of these new strategies. Methods A rat model of rp-ACLR using a tendinous autograft after complete mid-substance ACL transection was established. Twelve weeks following surgery, clinical outcomes and knee joints were assessed through visual gait analysis, Lachman tests, thigh perimeter measurements, magnetic resonance imaging, micro-computed tomography, and histology, to evaluate the morbidity of the procedure, accuracy of bone tunnel positioning, ACL remnants fate, osteoarthritis, and autograft bony integration. Results were compared with those obtained with isolated ACL transection without reconstruction and to right non-operated knees. Results and discussion Most operated animals were weight-bearing the day following surgery, and no adverse inflammatory reaction has been observed for the whole duration of the study. Autograft fixation with cortical screws provided effective graft anchorage until sacrifice. Healing of the transected ACL was not observed in the animals in which no graft reconstruction was performed. rp-ACLR was associated with a reduced degeneration of the ACL remnants (p = 0.004) and cartilages (p = 0.0437). Joint effusion and synovitis were significantly lower in the reconstructed group compared to the transected ACL group (p = 0.004). Most of the bone tunnel apertures were anatomically positioned in the coronal and/or sagittal plane. The most deviated bone tunnel apertures were the tibial ones, located in median less than 1 mm posteriorly to anatomical ACL footprint center. Conclusion This study presents a cost-effective, new relevant and objective rat model associated with low morbidity for the preliminary study of bio-implantable materials designed for remnants-preserving ACL surgery after mid-substance ACL tear.

Evaluation of the Use of Neuro Muscular Taping (NMT) in the Treatment of Postoperative Edema in Acute ACL Repair Surgery

Background: Surgical techniques for the treatment of Anterior Cruciate Ligament (ACL) injuries are exponentially improved in the past few decades. Nevertheless, edema and pain commonly accompany post-surgical procedures and when excessive, can adversely affect the healing course. In recent years, Neuro Muscular Taping (NMT) has been proposed as a new technique for the treatment of post-operative edema. Objective: In this study, we aimed to investigate the effects Neuro Muscular Taping (NMT) in the treatment of edema in the acute and post-acute postoperative phases of ACL repair surgery. Methods: Thirty patients (19 M, 11F; mean age: 27 y/o) with ACL injury were randomly assigned to two groups for the rehabilitation program: (1) An experimental group to receive a NMT treatment; or (2) A control group which underwent the standard-of-care rehabilitation protocols. Both groups where weekly monitored for 4 weeks after the surgery. Swelling was assessed through measurement of the limb circumference; post-operative pain was evaluated with VAS. After collection, data were processed by means of the Mann-Whitney and Wilcoxon statistical tests, through which we evaluated the percentage decrease in knee swelling of the operated limb. Results: In comparison to the control group, the experimental group showed significant improvements in swelling and pain. The circumference of the operated limb registered was: -2.4% ±0.1 in the NMT-treated group and + 0.3% ±0.2 in the control group in the first week (p = 0.030), -3.7% ±0.1 in the NMT-treated group and -0.63% ±0.3 in the control group in the second week (p = 0.038), -4.5% ±0.1 in the NMT-treated group and -1.2% ±0.3 in the control group in the third week (p = 0.019), -5.8% ±0.1 in the NMT-treated group and -2.4% ±0.3 in the control group in the fourth week (p = 0.019). VAS in the first week was 3.11 ±01.05 in NTM-treated group and 4.67 ±0.71 in the control group (p = 0.006). Our data showed a statistically significant reduction of the mean circumference of the lower limb at each time point and the reduction of mean VAS at the first week treated with NMT compared to the control group (p < 0.05). Conclusion: Our results revealed that NMT technique applied in the acute rehabilitation program of ACL surgery is effective in the treatment of postoperative edema.

Effect of an Anterior Cruciate Ligament Rupture on Knee Proprioception Within 2 Years After Conservative and Operative Treatment: A Systematic Review with Meta-Analysis

Background The anterior cruciate ligament (ACL) plays a major role in knee proprioception and is thus responsible for maintaining knee joint stability and functionality. The available evidence suggests that ACL reconstruction diminishes somatosensory feedback and proprioceptive functioning, which are vital for adequate joint positioning and movement control. Objective The aim of this systematic review and meta-analysis was to investigate the effect of an ACL rupture on knee proprioception after arthroscopic ACL repair surgery or conservative treatment. Methods A systematic review with meta-analysis was conducted according to the Preferred Reporting Guidelines for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The literature search was performed in the following databases from inception to 10th October 2020: PubMed, Web of Science, SPORTDiscus, Cochrane Library and Scopus. Randomized and non-randomized studies that evaluated proprioception using the joint position sense (JPS) and threshold to detection of passive motion (TTDPM) techniques at 15°–30° knee flexion with an external healthy control group in a time period between 6 and 24 months post injury or operation were included in the analysis. Results In total, 4857 studies were identified, from which 11 were included in the final quantitative analysis. The results demonstrated that proprioception after arthroscopic ACL repair surgery was significantly lower than in the healthy control group (JPS: standardized mean difference [SMD] 0.57, 95% confidence interval [CI] 0.27–0.87, p < 0.01, n = 6 studies; TTDPM: SMD 0.77, 95% CI 0.20–1.34, p < 0.01, n = 4 studies). There were no significant differences in proprioception between the conservative treatment group and the healthy control group (JPS: SMD 0.57, 95% CI − 0.69 to 1.84, p = 0.37, n = 4 studies; TTDPM: SMD 0.82, 95% CI − 0.02 to 1.65, p = 0.05, n = 2 studies), although measures for TTDPM were close to statistical significance. Conclusion The findings of the present systematic review and meta-analysis revealed that knee proprioception is persistently compromised 6–24 months following surgical treatment of ACL tears compared with healthy controls. The reduced kinesthetic awareness after ACL surgery is of high relevance for optimizing individual treatment plans in these patients. As the current literature is still scarce about the exact underlying mechanisms, further research is needed. Trial Registration The present systematic review was registered in PROSPERO (CRD42021198617).

Manual Lachman Test Underestimates Tibial Translation Compared to Standardized Generated Force: A Biomechanical Study of Cadaveric Anterior Cruciate Ligament Repair Using Internal Brace (205)

Objectives: With an increasing incidence over time, anterior cruciate ligament (ACL) rupture can produce functionally limiting knee instability that requires operative treatment to address the instability as well as prevent the development of osteoarthritis. Anteroposterior instability forms the basis of the most sensitive physical exam maneuver to examine the ACL for rupture, the Lachman test. This investigation has two goals: to assess the precision and accuracy of the manual Lachman test by comparing anterior tibial translation generated to that of a standardized applied force Lachman test, and to compare the anteroposterior stability of cadaver specimens with simulated ACL ruptures which were repaired with and without internal suture tape augmentation. Methods: The tibial plateau in ten cadaveric knees was divided into medial, middle and lateral reference points, which were monitored digitally during testing using Optotrak. Intact knees were subjected to both manual Lachman tests at 30 degrees of flexion and standardized 150N force Lachman tests utilizing a hook and pulley system with force transducer. The ACL’s of all specimens were then transected, and the ACL deficient knees were subjected to both the manual and standardized Lachman tests. The specimens were then randomly divided into two groups to be repaired with or without internal suture tape augmentation, and subsequently underwent 100, 250, and 500 cycles from 90 degrees of flexion through full extension with a frequency of .1Hz, after which the same standardized Lachman test was performed on all repaired specimens. Comparison of variances were made using a two-sample F-Test for variances. Comparison of means were made using a two sample t-test assuming unequal variances and one-way ANOVA. Significance was set at p </= 0.05. Results: Comparing ACL intact to ACL deficient states, the standardized Lachman test detected a significant difference in tibial translation at the medial (14.1mm versus 20.3mm, p=.031), middle (17.5mm versus 24.6mm, p=.011), and lateral (14.8mm versus 21.5mm, p=.050) reference points while the manual Lachman test only detected a significant difference at the middle (12.6mm versus 19.8mm, p=.026) reference point. In ACL deficient knees, there was a statistically significant underestimation in tibial translation when using the manual method as compared to the standardized method (17.4mm versus 22.3mm, p=0.046). When comparing the precision of the testing methods, F-Tests for variance did not yield significant differences between variances in measured tibial translation for the manual and standardized Lachman tests in either intact or ACL deficient knees. There were no statistically significant differences in measured tibial translation between specimens with intact ACL, ACL repair, and ACL repair with internal brace at the medial (14.1mm versus 13.7mm versus 16.45mm, p=0.462), middle (17.5mm versus 16.6mm versus 18.3mm, p=0.767), lateral (14.8mm versus 15.9mm versus 15.9mm, p=0.934), or call (15.5mm versus 15.2mm versus 16.9mm, p=0.748) reference points. Conclusions: Tibial translation generated by Lachman tests performed manually may be underestimated when compared to Lachman tests performed with a standard force, lending to difficulty detecting the ACL deficient state. ACL repair both with and without internal brace augmentation allowed for a return to pre-rupture levels of anteroposterior stability.

The Comparison of Clinical Result between Primary Repair of the Anterior Cruciate Ligament with Additional Internal Bracing and Anatomic Single Bundle Reconstruction—A Retrospective Study

Background: The current standard of treatment of anterior cruciate ligament (ACL) is reconstruction (ACLR). This technique has some disadvantages: poor proprioception, donor site morbidity and the inability to restore joint kinematics. ACL repair could be an alternative treatment. The purpose of the study was to compare the stability and the function after ACL primary repair versus single-bundle ACLR. Methods: In a retrospective study, 12 patients underwent primary ACL repair with internal bracing, 15 patients underwent standard ACLR. Follow-up examinations were evaluated at up to 2 years postoperatively. One patient in the ACL repair group was lost to follow-up due to re-rupture. The absolute value of anterior tibial translation (ATT) and the side-to-side difference in the same patient (ΔATT) were evaluated using the GNRB arthrometer. The Lysholm knee scoring was obtained. Re-ruptures and other complications were recorded. Results: Anterior tibial translation (ATT) was significantly decreased in the ACL repair group compared with the ACLR group (5.31 mm vs. 7.18 mm, respectively; p = 0.0137). Arthrometric measurements demonstrated a mean side-to-side difference (ΔATT) 1.87 (range 0.2 to 4.9) mm significantly decreased compared to ACLR 3.36 (range 1.2–5.6 mm; p = 0.0107). The mean Lysholm score was 85.3 points in the ACL repair group and 89.9 in ACLR group. No significant differences between ACL repair and ACLR were found for the Lysholm score. There was no association between AP laxity and clinical outcomes. There were two complications in the internal bracing group: one patient had re-rupture and was treated by ACLR, another had limited extension and had arthroscopic debridement. Conclusions: Anterior tibial translation was significantly decreased after ACL repair. Additionally, the functional results after ACL repair with internal bracing were comparable with those after ACLR. It should be noted that the two complications occurred. The current study supports further development of ACL repair techniques.

Rehabilitation Principles to Consider for Anterior Cruciate Ligament Repair

Context: Injury to the anterior cruciate ligament (ACL) is among the most common orthopaedic injuries, and reconstruction of a ruptured ACL is a common orthopaedic procedure. In general, surgical intervention is necessary to restore stability to the injured knee, and to prevent meniscal damage. Along with surgery, intense postoperative physical therapy is needed to restore function to the injured extremity. ACL reconstruction (ACLR) has been the standard of care in recent decades, and advances in surgical technology have reintroduced the prospect of augmented primary repair of the native ACL via a variety of methods. Evidence Acquisition: A search of PubMed database of articles and reviews available in English was performed through 2020. The search terms ACLR, anterior cruciate ligament repair, bridge enhanced acl repair, suture anchor repair, dynamic intraligamentary stabilization, internal bracing, suture ligament augmentation, and internal brace ligament augmentation were used. Study Design: Clinical review. Level of Evidence: Level 5. Results: No exact consensus exists on effective rehabilitation protocols after ACL repair techniques, as the variation in published protocols seem even greater than the variation in those for ACLR. For some techniques such as internal bracing and dynamic interligamentary stabilization, it is likely permissible for the patients to progress to full weightbearing and discontinue bracing sooner. However, caution should be applied with regard to earlier return to sport than after ACLR as to minimize risk for retear. Conclusion: More research is needed to address how physical therapies must adapt to these innovative repair techniques. Until that is accomplished, we recommend that physical therapists understand the differences among the various ACL surgery techniques discussed here and work with the surgeons to develop a rehabilitation protocol for their mutual patients. Strength of Recommendation Taxonomy (SORT): C.