ACL Repair: A Game Changer or Will History Repeat Itself? A Critical Appraisal

Repair with suture tape augmentation vs. reconstruction for ACL tears: A systematic review and meta-analysis

Background and aims

Interest in repairing ruptured anterior cruciate ligaments (ACL) has resurged, with suture tape augmentation (internal brace, ACL-IB) emerging as a prominent technique. However, the efficacy of ACL-IB compared to ACL reconstruction (ACL-R) remains unclear. We conducted a meta-analysis to address this gap.

Methods

Adhering to PRISMA guidelines, a search to PubMed, EMBASE and Cochrane Central for studies comparing ACL-IB to ACL-R was performed. The main endpoints were patient-reported outcomes (PROs) and failure rate. Muscle and joint function and surgery time were also assessed. Statistical analysis was performed by Review Manager 5.1.7.

Results

Nine studies comprising 1049 patients were included; 381 (36.3 %) underwent ACL-IB. Hamstring autografts were used for ACL-R in 421 patients (63.0 %). Most studies (6 of 8) reported follow-up longer than two years. The failure rate was higher in the ACL-IB group (risk ratio 3.62; 95 % CI 1.16 to 11.33; p = 0.03; I2: 52 %). No significant difference was found between groups for PROs, except KOOS Symptoms, which was significantly improved with ACL-IB (mean difference 2.49; 95 % CI 0.05 to 4.92; p = 0.05; I2: 0 %). ACL-IB resulted in stronger hamstrings (mean difference 11.99 %; 95 % CI 4.47 %-19.51 %; p = 0.002; I2: 73 %). No significant difference was found in anterior tibial translation and quadriceps strength.

Conclusions

ACL-IB had a higher failure rate compared to ACL-R. However, ACL-IB showed better hamstring strength and KOOS symptom score. No significant differences were seen in other PROs, time to return to sports, or quadriceps strength.

Histological Changes in the Blood Vessels of Ruptured Human Anterior Cruciate Ligaments

BACKGROUND

Anterior cruciate ligament (ACL) rupture is a commonly encountered sports injury worldwide. ACL rupture is known to have poor healing capacity, hypothesized to be due to low vascularity. ACL reconstruction surgery with ligament removal and tendon graft became essential for the higher grades of ACL tears. However, ACL-reconstructed patients faced post-traumatic osteoarthritis 10-15 years after surgery. In the recent past, the tibial remnant of ACL was shown to have intrinsic healing potential. Blood vessel density and the location of blood vessels of ACL remnants have critical implications in the newly upcoming remnant-preservation ACL reconstruction surgeries that showed better healing response. This study was performed to characterize the histological features of ruptured ACL remnants in terms of blood vessels to assess the healing potential and their utility in novel surgical techniques.

METHODS

This was a descriptive cross-sectional study in which the tibial remnant of 24 ruptured ACL samples was evaluated for blood vessel density (per sq. mm), luminal area (sq. µm), and location of blood vessels using hematoxylin and eosin (H&E) staining with ImageJ software (U. S. National Institutes of Health, Bethesda, Maryland, USA). The blood vessel density and location of blood vessels were compared among various groups based on the duration of injury and number of injuries.

RESULTS

Twenty-three male and one female adult patients with a mean duration of injury of 7.54 ± 5.63 months (range: 2-24 months) were included in the study. They were divided into three groups based on duration of injury: group I (2-5 months; n = 10), group II (6-8 months; n = 8), and group III (9-24 months; n = 6). The median blood vessel density (blood vessels per sq. mm) was 5.50 (3.30, 10.23) per sq. mm. There was no correlation of blood vessel density observed with duration of injury. All groups showed similar results statistically. More patients in earlier duration of injury showed very high range (10.1-40 per sq. mm) of blood vessels compared to the patients of later duration. Immature and intermediary blood vessels were identified denoting angiogenesis. Location of blood vessels varied in the groups based on duration of injury. There was no significant difference in blood vessel density and location of blood vessels between patients with single injury and those with multiple injuries.

CONCLUSION

The present study demonstrates the presence of healing potential of ruptured anterior cruciate ligaments in terms of blood vessel density, luminal area, and location of blood vessels. Future studies looking into the functional outcome would enhance the understanding of utility of novel remnant-preservation surgeries in place of standard graft reconstruction surgeries.

Acute anterior cruciate ligament rupture: can repair become an alternative to reconstruction: a meta-analysis of randomized controlled trials and cohort studies

PURPOSE

To perform a meta-analysis to compare clinical outcomes of anterior cruciate ligament (ACL) repair and ACL reconstruction for acute ACL rupture.

METHOD

We searched Pubmed, Embase, the Cochrane Library, and Web of Science databases to seek relevant studies. Clinical outcomes included failure rate, hardware removal rate, anteroposterior (AP) knee laxity, and patient-reported outcomes. In addition, subgroup analysis was carried out according to repair techniques, rupture locations, and study designs. Funnel plots were used to detect publication bias. All statistical analysis was performed using STATA (version 14.2, StataCorp).

RESULTS

A total of 10 articles were included in this study, comprising 5 randomized controlled trials (RCTs) and 5 cohort studies, involving a total of 549 patients. We found no statistical differences between the ACL repair and ACL reconstruction in the following outcomes: failure rate, AP knee laxity, International Knee Documentation Committee (IKDC) score, Lysholm score, Knee Injury and Osteoarthritis Outcome (KOOS) Score, and Tegner score. However, the ACL repair group had a higher hardware removal rate. Except for AP knee laxity results on different repair techniques, there was no statistical difference in other subgroup analyses.

CONCLUSION

Compared with ACL reconstruction, ACL repair shows similar results in clinical outcomes, and it is promising to be an effective alternative treatment for acute ACL rupture. Larger samples and higher-quality studies are needed to support our results and further explore the advantages of ACL repair in other aspects.

LEVEL OF EVIDENCE

Level III.

Comparison of Clinical Outcomes Between Modern Augmented ACL Repair and Autograft ACL Reconstruction: A Systematic Review and Meta-analysis of Studies With Minimum 2-Year Follow-up

Background

Anterior cruciate ligament (ACL) reconstruction has been the gold standard for primary ACL rupture since the 1990s. In the past decade, ACL repair has received renewed attention and increased research.

Purpose

To compare the clinical outcomes of modern augmented ACL repair versus autograft reconstruction for ACL ruptures.

Study Design

Systematic review; Level of evidence, 3.

Methods

A search of the PubMed, EMBASE, Scopus, Web of Science, and the Cochrane Library databases was conducted for prospective or retrospective comparative studies published between January 1, 2010, and January 3, 2023, with a minimum 2-year follow-up. Two independent reviewers performed data extraction and methodological quality assessment. Sensitivity analysis was performed to maintain the stability of results.

Results

Nine studies were included (minimum follow-up period, 24-60 months). The total sample size was 833 patients (augmented repair group: 358 patients; autograft ACL reconstruction group: 475 patients). There were 4 randomized controlled trials (level 1), 1 prospective comparative study (level 2), 2 retrospective comparative studies (level 3), and 2 case-control studies (level 3). The augmented ACL repair group attained significantly higher Lysholm score (weighted mean difference [WMD] = 1.57; 95% confidence interval [CI], 0.14-3.01; P = .03) and hamstring strength (WMD = 36.69; 95% CI, 29.07-44.31; P < .01) but had higher rates of hardware removal (odds ratio [OR] = 6.30; 95% CI, 2.44-16.23; P = .0001), reoperation (OR = 1.87; 95% CI, 1.33-2.62; P = .0003), and failure (OR = 1.58; 95% CI, 1.03-2.43; P = .0003) compared with the autograft ACL reconstruction group. No significant differences were observed between the repair and reconstruction groups regarding postoperative International Knee Documentation Committee scores, Tegner scores, knee laxity, satisfaction, ACL revisions, complications, and reoperation rather than revision.

Conclusion

Augmented ACL repair was associated with higher rates of reoperation, hardware removal, and failure compared with autograft ACL reconstruction in studies with minimum 2-year follow-up data. However, augmented ACL repair had higher Lysholm scores and hamstring strength versus autograft ACL reconstruction.

Tissue Augmentation Techniques in the Management of Ligamentous Knee Injuries

Despite early reports of high failure rates in knee ligament repair techniques resulting in favor of reconstruction, newer advances in surgical technology have shifted the attention back to repair with the addition of various tissue augmentation techniques. Ligament repair preserves proprioceptors in the native ligament and avoids autograft tendon harvest, minimizing the complications associated with donor site ruptures in reconstruction techniques. Tissue augmentation has been successfully used in knee ligamentous and tendon repair procedures, as well as in some upper extremity procedures. This study provides a clinical update on the surgical techniques, biomechanics, and outcomes with the application of various tissue augmentation techniques in the ligaments surrounding the knee joint.

Return to Sports After ACL Augmentation With Anterolateral Reconstruction (ALR) Harvesting Gracilis Only Compared With ACL Reconstruction With ALR Harvesting Both Hamstring Tendons

BACKGROUND

Anterior cruciate ligament (ACL) repair (ACL-Rp) is known to be a valuable alternative to ACL reconstruction (ACL-Rc) in selected indications. The majority of the ACL-Rp techniques recommend the use of a synthetic brace. The use of the gracilis allows both a biological internal brace and anterolateral ligament reconstruction (ALR).

PURPOSE

The primary objective was to compare the early ability to return to sports between patients who underwent ACL-Rp using a gracilis autograft as an internal brace augmentation with ALR and patients who underwent the conventional ACL-Rc with ALR technique sacrificing both the gracilis and the semitendinosus. The secondary objective was to compare the failure rate, clinical scores, and return to sports at a minimum follow-up of 2 years.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective analysis was undertaken. A total of 49 patients who underwent ACL-Rp with ALR between December 2018 and May 2019 were propensity matched at a 1:1 ratio to those who underwent ACL-Rc with ALR during the same period. The decision to perform ACL-Rp with ALR was based on preoperative selection and intraoperative arthroscopic findings: proximal avulsion tear, partial ACL tear, low- to midlevel sports participation, and good tissue quality. The ability to return to sports was assessed using isokinetic tests and the Knee Santy Athletic Return to Sport test functional test at 6 months postoperatively. At the final follow-up, knee laxity parameters, return to sports, and clinical outcome (Lysholm score, Tegner Activity Scale score, International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, and Anterior Cruciate Ligament-Return to Sport after Injury score) were recorded.

RESULTS

The ACL-Rp group had significantly less hamstring strength deficit when compared with their counterparts who underwent ACL-Rc (0.2% vs 10.2% in concentric, P < .001; 2.5% vs 14% in eccentric, P < .001). The mean Knee Santy Athletic Return to Sport test score was significantly higher in the ACL-Rc group (69.7% ± 16.6% [range, 19%-100%] vs 61% ± 16.8% [range, 19%-100%]; P = .001). In the ACL-Rp group, 61% (30/49) of the patients were authorized to return to pivot sports versus 41% (20/49) in the ACL-Rc group (P = .04). At a mean final follow-up of 31.4 ± 3.5 months, no significant differences were demonstrated between groups with respect to clinical scores and knee laxity parameters. There was a trend for a higher failure rate in the ACL-Rp group without any significance (ACL-Rp: 6.1% [3/49] vs ACL-Rc: 0%; P = .08).

CONCLUSION

At 6 months after operation, harvesting only the gracilis with this ACL-Rp and augmentation with ALR technique was linked to a better early ability to return to sports compared with the ACL-Rc with ALR technique harvesting both the gracilis and semitendinosus. This technique had a limited effect on early flexion strength and provided a satisfactory rerupture rate.

Arthroscopic Anterior Cruciate Ligament Primary Repair With Synthetic Augmentation and Fixation With the Knotless Suture Anchor

An anterior cruciate ligament (ACL) tear is one of the most common ligament injuries in athletes. The arthroscopic ACL reconstruction procedure is the gold standard for treatment. However, the improvement in injury classification and suture materials has subsequently made arthroscopic ACL primary repair an alternative surgical treatment option. This Technical Note describes an arthroscopic ACL primary repair with synthetic augmentation made of several high-strength sutures and fixation with the knotless suture anchor. The reinforced synthetic material acts as a structural tie to support the ACL while it heals.

Spontaneous healing of acute ACL ruptures: rate, prognostic factors and short-term outcome

INTRODUCTION

Anterior cruciate ligament (ACL) reconstruction is considered the first line treatment in ACL rupture. However, some patients return to high intensity sport activities and show a normal knee function without ACL reconstruction. Therefore, aim of this study was to evaluate the rate and prognostic factors of spontaneous healing in patients with ACL rupture and the short-term functional outcome.

METHODS

The rate, prognostic factors and short-term functional results of spontaneous healing in patients with ACL rupture were evaluated in 381 patients. Morphology of ACL rupture and extent of posterior tibial slope (PTS) were classified by MR- and x-ray imaging. In patients with normal knee stability in anesthesia examination and healed ACL during the arthroscopy 6 weeks after trauma ACL reconstruction was canceled. IKDC -, Tegner Activity Score, KT 1000 testing and radiological characteristics were collected 12 months postoperatively in these patients.

RESULTS

14.17% of the patients with ACL rupture showed a spontaneous healing after 6 weeks. Femoral ACL-rupture (p < 0.02) with integrity of ligament stump > 50% (p < 0.001), without bundle separation (p < 0.001) and decreased PTS (p < 0.001) was found significantly more often in patients with a spontaneous healed ACL. The average IKDC score was high at 84,63 in patients with healed ACL at 1 year follow-up, but KT 1000 testing was inferior compared to non-injured side.

CONCLUSION

Spontaneous healing of a ruptured ACL happened in 14% of the patients. Especially in low-demand patients with femoral single bundle lesions without increased posterior tibial slope delayed ACL surgery should be considered to await the possibility for potential spontaneous ACL healing.

Clinical outcomes in dynamic intraligamentary stabilization technique for anterior cruciate ligament tear: A meta-analysis

BACKGROUND

To compare the clinical outcome between dynamic intraligamentary stabilization (DIS) and anterior cruciate ligament (ACL) reconstruction in ACL tears.

METHODS

PubMed, the Cochrane Library, and Embase databases were searched to identify published articles on clinical studies comparing DIS versus ACL reconstruction. The results of the eligible studies were analyzed in terms of anteroposterior knee laxity translation (ΔATT) between the injured and contralateral knees, and subjective International Knee Documentation Committee (IKDC), Lysholm score, Tegner score, and ipsilateral ACL failure, implant removal, and ACL revision.

RESULTS

Five clinical studies including 429 patients with ACL tears met the inclusion criteria. DIS showed statistically comparable outcomes of ΔATT (P = .12), IKDC (P = .38), Tegner (P = .82), ACL failure (P = .50), ACL revision (P = .29) with ACL reconstruction. A significantly higher rate of implant removal (odds ratio for DIS vs ACL reconstruction, 7.73; 95% confidence interval [CI], 2.72-22.00; P = .0001) but statistically higher Lysholm score (mean difference between DIS and ACL reconstruction, 1.59; 95% CI, 0.24-2.93; P = .02) were found in DIS group.

CONCLUSION

Five clinical studies including 429 patients with ACL tears met the inclusion criteria. DIS showed statistically comparable outcomes of ΔATT (P = .12), IKDC (P = .38), Tegner (P = .82), ACL failure (P = .50), ACL revision (P = .29) with ACL reconstruction. A significantly higher rate of implant removal (odds ratio for DIS vs ACL reconstruction, 7.73; 95% CI, 2.72-22.00; P = .0001) but statistically higher Lysholm score (mean difference between DIS and ACL reconstruction, 1.59; 95% CI, 0.24-2.93; P = .02) were found in DIS group.

Clinical Research Progress of Internal Brace Ligament Augmentation Technique in Knee Ligament Injury Repair and Reconstruction: A Narrative Review

Knee ligament injuries are most common in sports injuries. In general, ligament repair or reconstruction is necessary to restore the stability of the knee joint and prevent secondary injuries. Despite advances in ligament repair and reconstruction techniques, a number of patients still experience re-rupture of the graft and suboptimal recovery of motor function. Since Dr. Mackay's introduction of the internal brace technique, there has been continuous research in recent years using the internal brace ligament augmentation technique for knee ligament repair or reconstruction, particularly in the repair or reconstruction of the anterior cruciate ligament. This technique focuses on increasing the strength of autologous or allograft tendon grafts through the use of braided ultra-high-molecular-weight polyethylene suture tapes to facilitate postoperative rehabilitation and avoid re-rupture or failure. The purpose of this review is to present detailed research progress in the internal brace ligament enhancement technique of knee ligament injury repair as well as the reconstruction from biomechanical and histological research and clinical studies and to comprehensively assess the value of the application of this technique.

Arthroscopic biological internal bracing with remnant repair for subacute ACL femoral avulsions

Arthroscopic anterior cruciate ligament (ACL) reconstruction predictably restores sagittal plane knee stability, however its inability to replicate a complex fan-shaped ligament of multiple fascicles, along with deficient restoration of normal rotational knee kinematics, results in failure to reverse a high risk for premature post-traumatic osteoarthritis. Although arthroscopic repair for acute ACL femoral avulsions is proposed to counter these deficiencies, the risk of early failure following non-healing, along with lack of convincing evidence of efficacy has impeded its universal acceptance. Moreover, since ACL repair needs to be performed in the acute phase following injury, it has an increased risk of developing arthrofibrosis, besides precluding any possibility to achieve natural healing of an ACL avulsion with non-operative treatment. The technique of biological internal bracing with remnant repair incorporates the advantages of both reconstruction and repair, and is indicated for patients with persistent ACL deficiency in the subacute phase (6-12 weeks) following an ACL femoral avulsion. This operation essentially involves two steps. The step of biological internal bracing is similar to a conventional ACL reconstruction using a small diameter hamstring graft that is targeted to the centre of the anteromedial ACL bundle on the femur, whereas the tibial socket is located posteriorly within the ACL tibial footprint so as to preserve the anterior fan-shaped morphology of the ACL tibial insertion. The second step involves repairing the remnant ACL tibial stump using one of three techniques. Although technically more complex than an ACL reconstruction, this novel technique provides native anatomy restoration with potential biomechanical and functional advantages, and should be considered for unhealed subacute ACL avulsion injuries.

The Minimal Clinically Important Difference, Patient Acceptable Symptom State, and Clinical Outcomes of Anterior Cruciate Ligament Repair Versus Reconstruction: A Matched-Pair Analysis From the SANTI Study Group

BACKGROUND

There has been increasing interest in anterior cruciate ligament (ACL) repair because of theoretical advantages over ACL reconstruction; however, the contemporary literature has failed to provide high-quality evidence to demonstrate these advantages.

PURPOSE

To compare the clinical and functional outcomes of ACL repair versus ACL reconstruction at a minimum follow-up of 2 years.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients who underwent ACL repair were propensity matched (based on demographics, time between injury and surgery, knee laxity parameters, presence of meniscal lesions, preoperative activity level, and sport participation), in a 1:1 ratio, to those who underwent ACL reconstruction during the same period. Isokinetic testing was used to evaluate strength deficits at 6 months postoperatively. Knee laxity parameters were evaluated at 12 months. Complications, return to sport, and patient-reported outcome scores were recorded at final follow-up.

RESULTS

In total, 75 matched pairs (150 patients) were evaluated. The repair group had significantly better mean hamstring muscle strength at 6 months compared with the reconstruction group (1.7% ± 12.2% vs -10.0% ± 12.8%, respectively; P < .0001). At a mean final follow-up of 30.0 ± 4.8 months, the repair group had a significantly better mean Forgotten Joint Score-12 (FJS-12) score compared with the reconstruction group (82.0 ± 15.1 vs 74.2 ± 21.7, respectively; P = .017). Noninferiority criteria were met for ACL repair, compared with ACL reconstruction, with respect to the subjective International Knee Documentation Committee score (86.8 ± 9.0 vs 86.7 ± 10.1, respectively; P < .0001) and side-to-side anteroposterior laxity difference (1.1 ± 1.4 vs 0.6 ± 1.0 mm, respectively; P < .0001). No significant differences were found for other functional outcomes or the pivot-shift grade. There were no significant differences in the rate of return to the preinjury level of sport (repair group: 74.7%; reconstruction group: 60.0%; P = .078). A significant difference was observed regarding the occurrence of ACL reruptures (repair group: 5.3%; reconstruction group: 0.0%; P = .045). Patients who experienced a failure of ACL repair were significantly younger than those who did not (26.8 vs 40.7 years, respectively; P = .013). There was no significant difference in rupture rates between the repair and reconstruction groups when only patients aged >21 years were considered (2.9% vs 0.0%, respectively; P = .157). The minimal clinically important difference and Patient Acceptable Symptom State (PASS) thresholds were defined for the ACL repair group. A significantly greater proportion of patients in the repair group achieved the PASS for the FJS-12 compared with their counterparts in the reconstruction group (77.3% vs 60.0%, respectively; P = .034).

CONCLUSION

ACL repair was associated with some advantages over ACL reconstruction including superior hamstring muscle strength at 6 months and significantly better FJS-12 scores. However, the failure rate was significantly higher after ACL repair, and younger patients were particularly at risk.

Comparable Instrumented Knee Joint Laxity and Patient-Reported Outcomes After ACL Repair With Dynamic Intraligamentary Stabilization or ACL Reconstruction: 5-Year Results of a Randomized Controlled Trial

BACKGROUND

Technical innovation has led to the renaissance of anterior cruciate ligament (ACL) repair in the past decade.

PURPOSE/HYPOTHESIS

The present study aimed to compare instrumented knee joint laxity and patient-reported outcomes (PROs) after ACL repair with those after primary ACL reconstruction for acute isolated ACL tears. It was hypothesized that ACL repair would lead to comparable knee joint stability and PROs at 5 years postoperatively in comparison with ACL reconstruction.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 85 patients with acute ACL tears were randomized to undergo either ACL repair using dynamic intraligamentary stabilization (DIS) or primary ACL reconstruction with a semitendinosus tendon autograft. The primary outcome was the side-to-side difference in anterior tibial translation (ΔATT) assessed by Rolimeter testing at 5 years postoperatively. Follow-up examinations were performed at 1, 2, and 5 years. PROs were assessed using the Tegner activity scale, the International Knee Documentation Committee (IKDC) subjective score, and the Lysholm score. Furthermore, the rates of recurrent instability, other complications, and revision surgery were recorded. A power analysis was performed a priori, and the Friedman test, Mann-Whitney U test, and Bonferroni correction were applied for statistical comparisons with significance set at P < .05.

RESULTS

The mean age at inclusion was 28.3 ± 11.5 years in the ACL repair group and 27.1 ± 11.5 years in the ACL reconstruction group. At 5 years postoperatively, a total of 64 patients (ACL repair: n = 34 of 43 [79%]; ACL reconstruction: n = 30 of 42 [71%]) were available for follow-up. At 5 years, ΔATT was 1.7 ± 1.6 mm in the ACL repair group and 1.4 ± 1.3 mm in the ACL reconstruction group (P = .334). Preinjury PROs were restored as soon as 1 year after surgery and plateaued until 2 and 5 years postoperatively in both groups. At the 5-year follow-up, the mean Lysholm score was 97.0 ± 5.4 versus 94.5 ± 5.5 (P = .322), respectively, and the mean IKDC subjective score was 94.1 ± 9.9 versus 89.9 ± 7.8 (P = .047), respectively, in the ACL repair group versus ACL reconstruction group. At 5 years postoperatively, 12 patients in the ACL repair group (35%; age <25 years: n = 10/12; Tegner score ≥7: n = 10/12) had recurrent instability, of whom 10 underwent single-stage revision ACL reconstruction. In the ACL reconstruction group, there were 6 patients with recurrent instability (20%; age <25 years: n = 6/6; Tegner score ≥7: n = 5/6); however, in 5 patients, staged revision was required. Differences between both groups regarding recurrent instability (P = .09) or ACL revision surgery (P = .118) were not statistically significant. Recurrent instability was associated with age <25 years and Tegner score >7 in both groups.

CONCLUSION

At 5 years after ACL repair with DIS, instrumented knee joint laxity and PROs were comparable with those after ACL reconstruction. Although no significant difference was found between repair and reconstruction, a critical appraisal of the rates of recurrent instability (35% vs 20%, respectively) and revision surgery (38% vs 27%, respectively) is needed. Young age and a high preinjury activity level were the main risk factors for recurrent instability in both groups. However, single-stage revision ACL reconstruction was possible in each case in the ACL repair group. Although ACL reconstruction remains the gold standard in the treatment of ACL tears, the present study supports the use of ACL repair with DIS as a feasible option to treat acute ACL tears in patients aged ≥25 years with low to moderate activity levels (Tegner score <7).

REGISTRATION

DRKS00015466 (German Clinical Trials Register).

A deep learning approach for anterior cruciate ligament rupture localization on knee MR images

Purpose: To develop and evaluate a deep learning-based method to localize and classify anterior cruciate ligament (ACL) ruptures on knee MR images by using arthroscopy as the reference standard.

Methods: We proposed a fully automated ACL rupture localization system to localize and classify ACL ruptures. The classification of ACL ruptures was based on the projection coordinates of the ACL rupture point on the line connecting the center coordinates of the femoral and tibial footprints. The line was divided into three equal parts and the position of the projection coordinates indicated the classification of the ACL ruptures (femoral side, middle and tibial side). In total, 85 patients (mean age: 27; male: 56) who underwent ACL reconstruction surgery under arthroscopy were included. Three clinical readers evaluated the datasets separately and their diagnostic performances were compared with those of the model. The performance metrics included the accuracy, error rate, sensitivity, specificity, precision, and F1-score. A one-way ANOVA was used to evaluate the performance of the convolutional neural networks (CNNs) and clinical readers. Intraclass correlation coefficients (ICC) were used to assess interobserver agreement between the clinical readers.

Results: The accuracy of ACL localization was 3.77 ± 2.74 and 4.68 ± 3.92 (mm) for three-dimensional (3D) and two-dimensional (2D) CNNs, respectively. There was no significant difference in the ACL rupture location performance between the 3D and 2D CNNs or among the clinical readers (Accuracy, p < 0.01). The 3D CNNs performed best among the five evaluators in classifying the femoral side (sensitivity of 0.86 and specificity of 0.79), middle side (sensitivity of 0.71 and specificity of 0.84) and tibial side ACL rupture (sensitivity of 0.71 and specificity of 0.99), and the overall accuracy for sides classifying of ACL rupture achieved 0.79.

Conclusion: The proposed deep learning-based model achieved high diagnostic performances in locating and classifying ACL fractures on knee MR images.

Trends in Primary Anatomical Single-Bundle Anterior Cruciate Ligament Reconstruction Practice in Adult Patients Prevalent Among Arthroscopy Surgeons of Six Southern States of India

BACKGROUND

Although guidelines from multiple scientific studies decide the general trend in ACLR practice, there is often a variation between scientific guidelines and actual practice.

METHODS

A 17-member committee comprised of sports surgeons with experience of a minimum of 10 years of arthroscopy surgery finalized a survey questionnaire consisting of concepts in ACL tear management and perioperative trends, intraoperative and post-operative practices regarding single-bundle anatomic ACLR. The survey questionnaire was mailed to 584 registered sports surgeons in six states of south India. A single, non-modifiable response was collected from each member and analyzed.

RESULTS

324 responses were received out of 584 members. A strong consensus was present regarding Hamstring tendons preference for ACLR, graft diameter ≥ 7.5 mm, viewing femoral footprint through the anterolateral portal, drilling femoral tunnel from anteromedial portal guided by ridges and remnants of femoral footprint using a freehand technique, suspensory devices to fix the graft in femur and interference screw in the tibia and post-operative bracing. A broad consensus was achieved in using a brace to minimize symptoms of instability of an ACL tear and antibiotic soaking of graft. There was no consensus regarding the timing of ACLR, preferred graft in athletes, pre-tensioning, extra-articular procedure, and return to sports. There was disagreement over hybrid tibial fixation and suture tapes to augment graft.

CONCLUSION

Diverse practices continue to prevail in the management of ACL injuries. However, some of the consensuses reached in this survey match global practices. Contrasting or inconclusive practices should be explored for potential future research.

Arthroscopic Anterior Cruciate Ligament Repair Versus Autograft Anterior Cruciate Ligament Reconstruction: A Meta-Analysis of Comparative Studies

Purpose

To compare the clinical outcomes of arthroscopic anterior cruciate ligament (ACL) repair and autograft ACL reconstruction for ACL ruptures.

Methods

PubMed, EMBASE, Scopus, Web of Science and The Cochrane Library were searched for relevant studies from 1 January 1990 to 21 March 2022. Two evaluators independently screened the literature, extracted data and assessed the methodological quality of the enrolled studies. Meta-analysis was conducted using RevMan 5.4 software.

Results

Ten studies with mean follow-up periods from 12 to 36 months were included. For 638 patients with ACL ruptures, arthroscopic ACL repair showed statistically comparable outcomes of failure (p = 0.18), complications (p = 0.29), reoperation other than revision (p = 0.78), Lysholm score (p = 0.78), Tegner score (p = 0.70), and satisfaction (p = 0.45) when compared with autograft ACL reconstruction. A significantly higher rate of hardware removal (p = 0.0008) but greater International Knee Documentation Committee (IKDC) score (p = 0.009) were found in the ACL repair group. The heterogeneity of the side-to-side difference of anterior tibial translation (ΔATT) was high (I 2 = 80%). After the sensitivity analysis, the I 2 decreased dramatically (I 2 = 32%), and the knees with ACL repair showed significantly greater ΔATT (P = 0.04).

Conclusion

For proximal ACL ruptures, arthroscopic ACL repair showed similar clinical outcomes, and even better functional performance when compared to autograft ACL reconstruction. ACL repair has a higher rate of hardware removal, and might be related to greater asymptomatic knee laxity. More high-quality prospective trials are needed to confirm our findings.

Anterior cruciate ligament repair with internal brace augmentation: A systematic review

BACKGROUND

Primary repair of anterior cruciate ligament (ACL) ruptures has re-emerged as a treatment option for proximal tears, with internal brace augmentation often utilised. The aim of this study is to provide an overview of the current evidence presenting outcomes of ACL repair with internal bracing to assess the safety and efficacy of this technique.

METHODS

All studies reporting outcomes of arthroscopic primary repair of proximal ACL tears, augmented with internal bracing from 2014-2021 were included. Primary outcome was failure rate and secondary outcomes were subjective patient reported outcome measures (PROMs) and objective assessment of anteroposterior knee laxity.

RESULTS

Nine studies were included, consisting of 347 patients, mean age 32.5 years, mean minimum follow up 2 years. There were 36 failures (10.4%, CI 7.4% - 14.1%). PROMs reporting was variable across studies. KOOS, Lysholm and IKDC scores were most frequently used with mean scores > 87%. The mean Tegner and Marx scores at follow-up were 6.1 and 7.8 respectively. The mean side to side difference measured for anteroposterior knee laxity was 1.2mm.

CONCLUSIONS

This systematic review with meta-analysis shows that ACL repair with internal bracing is a safe technique for treatment of proximal ruptures, with a failure rate of 10.4%. Subjective scores and clinical laxity testing also revealed satisfactory results. This suggests that ACL repair with internal bracing should be considered as an alternative to ACL reconstruction for acute proximal tears, with the potential benefits of retained native tissue and proprioception, as well as negating the need for graft harvest.

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.