Efficacy of Nonaugmented, Static Augmented, and Dynamic Augmented Suture Repair of the Ruptured Anterior Cruciate Ligament: A Systematic Review of the Literature

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.

Can repair be an alternative to reconstruction in the management of acute anterior cruciate ligament rupture: A meta-analysis of randomized controlled trials

Purpose

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

Methods

Studies were searched on PubMed, Web of Science, and EMBASE for randomized controlled trials comparing ACL repair versus ACL reconstruction for ACL rupture. The bias risk was based on the Cochrane Handbook for Systematic Reviews of Interventions. Clinical outcomes included IKDC score, Lysholm score, Tegner score, anteroposterior (AP) knee laxity, and failure rate. The funnel plots were used to detect publication bias.

Results

Six randomized controlled study (RCTs) were included in this meta-analysis, involving a total of 478 patients. The mean follow-up varied from 1 to 5 years. The mean age of patients was between 17 and 29.1 years, the mean time from injury to surgery was 13-39 days. We found no statistical differences between ACL repair and ACLR in IKDC score (0.11; 95% CI, -0.17 to 0.40; p = 0.440; I 2 = 56.8%), Lysholm score (0.16; 95% CI, -0.10 to 0.42; p = 0.214; I 2 = 28.8%), Tegner score (0.05; 95% CI, -0.23 to 0.34; p = 0.719; I 2 = 0.0%), AP knee laxity (0.05; 95% CI, -0.17 to 0.27; p = 0.636; I 2 = 0.0%), and failure rate (RR, 1.10; 95% CI, 0.70-1.72; p = 0.695; I 2 = 27.3%).

Conclusion

ACL repair showed similar clinical outcomes compared with ACLR, and it could replace ACLR as an appropriate surgical method for acute proximal ACL rupture, but the indication and selection of patients are essential to be considered. Large numbers and more high-quality studies are still needed in the future to verify our results.

Level of Evidence

Level I.

Mesenchymal Stem Cell Exosome and Fibrin Sealant Composite Enhances Rabbit Anterior Cruciate Ligament Repair

BACKGROUND

The anterior cruciate ligament (ACL) fails to heal after rupture, leading to joint instability and an increased risk of osteoarthritis. Mesenchymal stem/stromal cell (MSC) exosomes have reported wide-ranging therapeutic efficacy; however, their potential for augmenting ACL repair remains to be investigated.

PURPOSE

To evaluate the use of MSC exosomes with fibrin sealant on biological augmentation of ACL healing after suture repair and their effects on ACL fibroblast functions.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twelve rabbit knees underwent ACL transection and suture repair. MSC exosome and fibrin composite (Exosome+Fibrin) or fibrin (Fibrin) alone was used to supplement the suture repair in 6 knees. ACL repair was assessed by magnetic resonance imaging at 6 and 12 weeks postoperatively and by histologic and immunohistochemical analyses at 12 weeks. To investigate the mechanisms through which MSC exosomes augment ACL repair, metabolic activity, proliferation, migration, and matrix synthesis assays were performed using the primary ACL fibroblasts. RNA sequencing was also performed to assess global gene expression changes in exosome-treated ACL fibroblasts.

RESULTS

Based on magnetic resonance imaging findings, 5 of 6 Exosome+Fibrin-treated ACLs were completely or partially healed, as opposed to 5 of 6 Fibrin-treated ACLs appearing torn at 6 and 12 weeks postoperatively. Additionally, 4 of 6 Exosome+Fibrin-treated ACLs were isointense, as compared with 5 of 6 Fibrin-treated ACLs that were hyperintense, indicating improved remodeling and maturation of the repaired ACLs with Exosome+Fibrin treatment. Histologically, Exosome+Fibrin-treated ACLs showed more organized collagen fibers and abundant collagen deposition, with a high amount of collagen I and relatively lower amount of collagen III, which are consistent with the matrix structure and composition of the normal ACL. Cell culture studies using ACL fibroblasts showed that MSC exosomes enhanced proliferation, migration, and collagen synthesis and deposition, which are cellular processes relevant to ACL repair. Further gene set enrichment analysis revealed key pathways mediated by MSC exosomes in enhancing proliferation and migration while reducing matrix degradation of ACL fibroblasts.

CONCLUSION

The combination of MSC exosomes and fibrin sealant (Exosome+Fibrin) applied to a suture repair enhanced the morphologic and histologic properties of the ACL in a rabbit model, and these improvements could be attributed to the augmented functions of ACL fibroblasts with exosome treatment.

CLINICAL RELEVANCE

This work supports the use of MSC exosomes in biological augmentation of ACL healing after suture repair.

Meniscal repair with concomitant suture-augmented ACL repair versus reconstruction: a retrospective cohort study

INTRODUCTION

This study evaluated patient-reported outcome measures (PROM) and reinjury rates in patients undergoing meniscal repair with concomitant suture-augmented (SA) anterior cruciate ligament reconstruction (ACLR) or repair (ACLr).

MATERIALS AND METHODS

We performed a retrospective cohort study of patients who underwent concomitant meniscus and ACL procedures by a single surgeon between 2015 and 2021. Inclusion criteria were meniscal repair with concomitant SA ACLR or SA ACLr, at least two years of follow-up, and participation in postoperative PROM surveys. Exclusion criteria were concomitant meniscectomy, multiligament repair or reconstruction, or other concomitant procedures at the time of the index operation. After a minimum of two years of follow-up, data was collected on reinjury and patient reported outcome measures, including Knee Injury and Osteoarthritis Outcome Score (KOOS), Single Assessment Numeric Evaluation (SANE), Visual Analog Pain Scale, and Veterans Rand 12 Item Survey (VR-12).

RESULTS

39 total patients were identified, 12 ACL repairs and 27 ACL reconstructions. 6 patients were lost to follow-up, with 10 patients in the ACLr cohort and 23 patients in the ACLR cohort included in the study. Meniscus tear laterality was not significantly different between the cohorts (p = 0.3828). There were two meniscal repair failures in the ACLr cohort compared to one in the ACLR cohort (p = 0.2117). There was one ACL reinjury in the ACLr cohort compared to zero reinjuries in the ACLR cohort (p = 0.3030). In a univariate analysis of PROMs, there were no significant differences in postoperative KOOS (p = 0.3308), VAS (p = 0.9955), SANE (p = 0.3449), VR-12M (p = 0.4705), or VR-12P (p = 0.7903) scores between the cohorts. In a multivariable analysis controlling for age, sex, BMI, meniscus tear laterality, and meniscus tear pattern, choice of ACL procedure was not a significant predictor of any postoperative PROM. 23 total patients, 6 ACL repairs and 17 ACL reconstructions had preoperative data available and were evaluated for changes in PROMs after surgery. There were clinically significant improvements in KOOS and SANE scores in both cohorts postoperatively.

CONCLUSION

In this cohort of patients, meniscal repair with SA ACLr was not inferior to meniscal repair with SA ACLR at two years of follow-up.

A Technique of Arthroscopic Primary Anterior Cruciate Ligament Repair With Polyester Suture Tape Augmentation

Restoring anterior cruciate ligament (ACL) function after a rupture is critical for reducing long-term knee damage. Primary reconstruction is well established as a golden standard for treatment of complete ACL tear. Nevertheless, carefully selected patients can substantially benefit from a primary repair in comparison to reconstruction. We present a technique of arthroscopic primary ACL repair with polyester suture tape augmentation. Our method expands the spectrum of ACL repair techniques by creating a comfortable pulley-like system of tensioning the ligament and suture tape with a cortical button-suture construct.

Anterior cruciate ligament primary repair revision rates are increased in skeletally mature patients under the age of 21 compared to reconstruction, while adults (>21 years) show no significant difference: A systematic review and meta-analysis

PURPOSE

To evaluate the impact of age as a risk factor on the revision rates of anterior cruciate ligament (ACL) primary repair (ACLPR), dynamic intraligamentary stabilization (DIS) and bridge-enhanced ACL restoration (BEAR) compared to ACL reconstruction (ACLR).

METHODS

A systematic literature search was performed for comparative studies comparing outcomes for ACLPR, DIS or BEAR to ACLR. A random-effects meta-analysis was performed to assess nondifferentiated and age-differentiated (skeletally mature patients ≤21 and >21 years) ACL revision and reoperation risk, as well as results for subjective outcomes. Methodological study quality was assessed using the Risk of Bias Tool 2.0c and Methodological Index for Nonrandomized Studies tools.

RESULTS

A total of 12 studies (n = 1277) were included. ACLR demonstrated a lower nonage-stratified revision risk at 2 years versus ACLPR, DIS and BEAR, but a similar revision risk at 5 years when compared to DIS. However, an age-stratified analysis demonstrated a significantly increased ACLPR revision risk as compared to ACLR in skeletally mature patients ≤21 years of age (risk ratios [RR], 6.33; 95% confidence interval [CI], 1.18-33.87, p = 0.03), while adults (>21 years) showed no significant difference between groups (RR, 1.48; 95% CI, 0.25-8.91, n.s.). Furthermore, DIS reoperation rates were significantly higher than respective ACLR rates (RR, 2.22; 95% CI, 1.35-3.65, p = 0.002), whereas BEAR (RR, 1.07; 95% CI, 0.41-2.75, n.s.) and ACLPR (RR, 0.81; 95% CI, 0.21-3.09, n.s.) showed no differences. IKDC scores were equivalent for all techniques. However, ACLPR exhibited significantly better FJS (mean difference, 11.93; 95% CI, 6.36-17.51, p < 0.0001) and Knee injury and Osteoarthritis Outcome Score Symptoms (mean difference, 3.01; 95% CI, 0.42-5.60, p = 0.02), along with a lower Tegner activity reduction.

CONCLUSIONS

ACLPR in skeletally mature patients ≤21 years of age is associated with up to a six-fold risk increase for ACL revision surgery compared to ACLR; however, adults (>21 years) present no significant difference. Based on the current data, age emerges as a crucial risk factor and should be considered when deciding on the appropriate treatment option in proximal ACL tears.

LEVEL OF EVIDENCE

Level III.

Arthroscopic Anatomic Anterior Cruciate Ligament Primary Repair Restores Anterior Tibial Translation Intraoperatively at Time Zero With No Additional Effect of Suture Augmentation

PURPOSE

To intraoperatively evaluate the ability of anterior cruciate ligament (ACL) primary repair (ACLPR) to restore anterior tibial translation (ATT) at time zero and to assess the influence of additional suture augmentation (SA) on ATT.

METHODS

Patients with proximal ACL tears undergoing arthroscopic ACLPR with dual-suture anchor fixation were included in this time-zero clinical study. Laxity measurements were taken with a digital arthrometer to evaluate ATT stability preoperatively in the office (T0) as a standardized diagnostic tool, preoperatively under anesthesia (T1), at time zero intraoperatively after ACLPR but prior to SA fixation (T2), and after SA fixation (T3).

RESULTS

A total of 27 patients (mean age ± standard deviation [SD], 35.1 ± 12.0 years) with proximal ACL tears and significant preoperative (T0) ATT side-to-side differences (SSDs) (mean ± SD, 4.1 ± 1.5 mm) were evaluated. ACLPR was shown to restore ATT SSD at time zero (mean ± SD, 0.2 ± 1.1 mm) given that a significant reduction in ATT SSD (mean difference ± standard error, -4.7 ± 0.21 mm; P < .001) was achieved when comparing preoperative and intraoperative measurements after separate refixation of both ACL bundles with suture anchors. Additional SA fixation did not further decrease ATT when comparing measurements of the ipsilateral leg after ACL refixation and after SA fixation (mean difference ± SD, 0.03 ± 0.22 mm; P = .496).

CONCLUSIONS

ACLPR with dual-suture anchor fixation restores time-zero ATT laxity in adults with proximal ACL tears. Additional SA fixation in full knee extension does not further decrease ATT.

CLINICAL RELEVANCE

This study provides important information about the effectiveness of ACLPR in restoring ATT. SA with the knee fixed in full knee extension does not further decrease ATT; therefore, augmentation may not lead to overconstraint of the knee or stress shielding of the repaired ACL.

Editorial Commentary: Primary Repair of the Anterior Cruciate Ligament Shows Positive Midterm Outcomes When Properly Indicated

Anatomic anterior cruciate ligament (ACL) reconstruction is the gold standard treatment for ACL injury and has been shown to restore the 3-dimensional joint laxity. Recently, however, there is renewed interest in primary repair of the injured ACL in selected cases. Research shows that, in some cases, short- and midterm outcomes of ACL repair are favorable, albeit with greater failure rates than ACL reconstruction. No long-term outcomes are yet available, which could address whether repair reduces risk of osteoarthritis relative to reconstruction with a graft. Historically, primary repair showed poor outcomes, but for proximal and acute injuries with good vascularity, innovations such as suture anchors, dynamic intraligamentary stabilization, and suture tape augmentation show promise, particularly in paediatric patients. The old orthopaedic dogma that "ACL cannot heal" is not entirely correct.

Arthroscopic Primary Repair of Proximally Based Anterior Cruciate Ligament Tear With Augmentation and All-Epiphyseal Fixation

Arthroscopic anterior cruciate ligament (ACL) reconstruction has been the gold standard of care for ACL injuries for many years. Recently, there has been growing literature and interest in arthroscopic primary ACL repair in select patients with predominantly proximally based ACL tears. This Technical Note demonstrates a surgical technique that offers an efficient minimally invasive and physeal-sparing anatomic ACL repair with all-inside internal brace augmentation that in the short term has offered good results for our patients.

Arthroscopic Primary Repair of Proximal Anterior Cruciate Ligament Tears Using a Continuous Bundle Suture Technique With Simplified Suture Passing

Anterior cruciate ligament (ACL) injury is a common knee sports injury, with proximal ACL tears accounting for most cases. Arthroscopic ACL preservation has shown great potential in repairing ACL anatomic and biological function, with less tissue damage and slightly higher failure rates. Although many techniques for repairing the ACL have been developed, there are still many problems with the existing technology, such as the cumbersome operation of the traditional hook and needle breakage of the Scorpion suture passer (Arthrex). Herein, to further improve operational convenience and reliability, we developed a continuous bundle suture technique for primary repair of proximal ACL tears with suture anchor fixation. This technique aims to achieve continuous suturing with no additional auxiliary suture for guiding suturing by using a passer as a pusher in the suture hook to push out the suture loaded in the tip of the hook after the hook passes through the ligament. This technique takes advantage of the economics of the suture hook and the convenience of the Scorpion suture passer, allowing for flexible application of the suture hook to conveniently achieve anteromedial and posterolateral bundle repair for patients with proximal ACL tears.

Incidence of Osteoarthritis Between ACL Reconstruction With Different Graft Types and Between ACL Reconstruction and Repair: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Background

Variation in stiffness, fixation methods, and donor-site morbidity after anterior cruciate ligament reconstruction (ACLR) with different graft types and with anterior cruciate ligament suture repair (ACLSR) can lead to differences in dynamic knee laxity and consequent differences in posttraumatic osteoarthritis (PTOA) development.

Purpose

To compare the incidence of PTOA between different graft types used for primary ACLR and between primary ACLR and ACLSR. It was hypothesized that the incidence of PTOA would vary between ACLR with different autografts and allografts and between ACLR and ACLSR.

Study Design

Systematic review; Level of evidence, 1.

Methods

A search of the literature was performed to identify all randomized controlled trials (RCTs) comparing radiographic evidence of PTOA after ACLR between different graft types-hamstring tendon (HT) autograft, bone-patellar tendon-bone (BPTB) autograft, quadriceps tendon autograft, and allograft-and between ACLR and ACLSR. The minimum follow-up was 2 years. Study quality was assessed using the modified Coleman Methodology Score. A meta-analysis was performed to determine whether there was a difference in the incidence of PTOA between the different graft types and between ACLR and ACLSR.

Results

Eleven randomized controlled trials were included in the meta-analysis-HT: 440 patients (mean follow-up, 9.7 years); BPTB: 307 patients (mean follow-up, 11.8 years); allograft: 246 patients (mean follow-up, 5 years); ACLSR, 22 patients (5 years). No study reporting the incidence after ACLR with quadriceps tendon was included. The study quality ranged from 70 to 88. The meta-analysis indicated no significant difference in the incidence of PTOA between graft types used for ACLR and between ACLR and ACLSR (risk ratios: HT vs BPTB, 1.05; HT vs allograft, 0.81; BPTB vs allograft, 0.82; HT vs ACLSR, not estimable [P > .05 for all]). The combined number of patients with PTOA in all studies per graft type showed that patients who underwent ACLR with a BPTB autograft had the highest percentage of PTOA (HT, 23.4%; BPTB, 29.6%; allograft, 8.1%; ACLSR, 0%). However, excluding studies with a follow-up <5 years resulted in similar outcomes for patients with an HT autograft and a BPTB autograft.

Conclusion

This meta-analysis reported no difference in the incidence of PTOA between graft types used for ACLR and between ACLR and ACLSR. More research is necessary to make a reliable conclusion about which technique is associated with the lowest incidence of PTOA after ACL surgery.

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.

Outcomes of Primary Anterior Cruciate Ligament (ACL) Repair for Proximal Tears: A Systematic Review and Meta-Analysis

The purpose of this study is to compare failure rates among different techniques of primary anterior cruciate ligament (ACL) repair for the treatment of proximal ACL ruptures. Meta-analysis and systematic review were completed, and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Studies from Embase, Cochrane, and PubMed published between June 2011 and June 2022 reporting outcomes of primary ACL repair on proximal tears with a minimum two-year follow-up were included. Primary ACL repair was divided into dynamic, static, and non-augmented repair. The primary outcome was failure rates, and the secondary outcomes included patient-reported outcomes (PROs) and anterior tibial stability (ATT). Eighteen studies on primary ACL repair were included, with a total of 614 patients (ages ranging from 6 to 65, 60% male). Only two studies were level 1 randomized controlled clinical trials. The static repair had a failure rate of 33 out of 261 (12.6%), non-augmented was 17 out of 179 (9.4%), and dynamic repair was 31 out of 174 (17.8%); no statistically significant difference was found comparing the failure rates (p = 0.090). PROs using the International Knee Documentation Committee (IKDC) and Lysholm scores had weighted averages of 91.7 (95% confidence interval (CI): 89.6-93.8) and 94.7 (95% CI: 92.7-96.7), respectively. ATT had a weighted average of 1.668 mm (95% CI: 1.002-2.334). The primary findings of this paper include a 12.6% combined failure rate for primary proximal ACL repair with no significant difference in failure rate or PROs when accounting for the methodology of repair at a minimum two-year follow-up. It is important to note the lack of high-quality randomized controlled trials, the heterogeneity of included studies, and the lack of long-term data. Despite these limitations, the findings of the current analysis suggest that primary repair may be a useful treatment option for indicated candidates with proximal ACL ruptures. Further long-term and higher-quality comparative studies on ACL reconstruction are warranted.

Reporting Bias in the Form of Positive Spin Is Highly Prevalent in Abstracts of Systematic Reviews on Primary Repair of the Anterior Cruciate Ligament

PURPOSE

To analyze reporting bias in the form of spin present in systematic reviews and meta-analyses on the topic of primary anterior cruciate ligament (ACL) repair.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed throughout this study. Peer-reviewed systematic reviews were collected from 3 databases (PubMed, Scopus, and SPORTDiscus), and their abstracts were assessed for the 15 most common types of spin. Articles were excluded if they were not published in English, had no evidence, were retracted, were published without an abstract, did not have full text available, or included cadaveric or nonhuman subjects. Full text quality was assessed using AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews Version 2). Fisher exact tests were used to examine associations between the different types of spin and other study characteristics such as AMSTAR 2 confidence rating, study design, and level of evidence.

RESULTS

Spin was present in the abstracts of 13 of 15 articles (86.7%). There were significant associations between PRISMA adherence and lower incidences of spin types 3, 6, and 8 (P = .029 for each). A critically low AMSTAR 2 confidence rating was significantly associated with an increased incidence of spin type 9 (P = .01), and a higher AMSTAR 2 score was significantly associated with decreased spin type 4 and type 5 (P = .039 and P = .048, respectively). A more recent year of publication was correlated with a lower incidence of spin type 14 (P = .044).

CONCLUSIONS

Spin is present in most systematic reviews and meta-analyses regarding primary repair of the ACL, with two-thirds of abstracts spinning evidence in favor of ACL repair. Standardized guidelines including the PRISMA guidelines and the AMSTAR 2 assessment tool were negatively correlated with spin. More recently published articles were found to contain significantly less spin, as were articles published in journals with higher Clarivate Impact Factors and Scopus CiteScores.

LEVEL OF EVIDENCE

Level V, systematic review of Level III through V studies.

Primary anterior cruciate ligament repair: Current concepts

The renewed interest in ACL repair over the last two decades stems from advances in modern arthroscopic techniques and clinical studies that have provided evidence that the ACL can reliably heal, and patients can return to sport at a comparable rate to ACL reconstruction patients. The ability to maintain and utilize native ACL tissue, with proprioceptive capabilities, and the smaller drill tunnels needed to repair an ACL leads to an overall less invasive procedure and improved early rehabilitation. Additionally, repair avoids a variety of comorbidities associated with autograft harvest. This current concept review details modern techniques of ACL repair and their current studies, a review on the use of biologic enhancement in ACL repair, and other considerations to appropriately integrate ACL repair into the sports medicine orthopaedic surgeon's practice.

Favorable Patient-Reported, Clinical, and Functional Outcomes 2 Years After ACL Repair and InternalBrace Augmentation Compared With ACL Reconstruction and Healthy Controls

BACKGROUND

Recently, interest in anterior cruciate ligament (ACL) preservation and repair after proximal ACL tears has been resurrected. Although good clinical outcomes have been reported in the literature with adequate patient selection, to date detailed scientific evidence for the functional benefit of primary ACL repair with ligament augmentation is scarce.

PURPOSE

To compare patient-reported, clinical, and functional outcomes in patients 2 years after ACL repair and InternalBrace augmentation (ACL-IB) with age- and sex-matched patients 2 years after ACL reconstruction (ACL-R) and with matched healthy controls.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

In total, 29 patients 2 years after ACL-IB, 27 sex- and age- matched patients 2 years after ACL-R (hamstring autografts), and 29 matched healthy controls were included. Patient-reported outcomes were assessed using the International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, EQ-5D-5L, Tegner Activity Scale, and Anterior Cruciate Ligament Return to Sports after Injury scale. Surgery time was recorded. For clinical outcomes, range of motion and thigh and shank circumference were measured, and passive anterior translation was determined using the Rolimeter. Isokinetic muscle strength was measured using a Biodex dynamometer. The limb symmetry index (operated/contralateral or nondominant/dominant × 100), side-to-side differences (operated - contralateral, nondominant - dominant), and hamstring-quadriceps ratios were calculated for functional parameters. Failure and reoperation rates were not compared.

RESULTS

Two years after surgery, patients treated with ACL-IB showed good to excellent patient-reported outcomes comparable with those of patients after ACL-R. Surgery time, including concomitant surgeries, was significantly shorter in the ACL-IB group (mean, 81 minutes) compared with the ACL-R group (mean, 97 minutes) (P = .024). Isokinetic muscle strength was comparable between patient groups without significant differences in extensor and flexor strength or in hamstring-quadriceps ratios.

CONCLUSION

These results suggest that ACL-IB achieves comparable patient-reported, clinical, and functional outcomes with ACL-R at 2 years postoperatively and, after careful patient selection, should be considered as a valuable early treatment alternative for proximal ACL tears.

REGISTRATION

NCT04429165 (ClinicalTrials.gov identifier).

Functional leg performance 2 years after ACL surgery: a comparison between InternalBrace™-augmented repair versus reconstruction versus healthy controls

BACKGROUND

While clinical and patient-reported outcomes have been investigated in patients after InternalBrace™-augmented anterior cruciate ligament repair (ACL-IB), less is known regarding restoration of functional performance. We aimed to determine differences in functional performance within and between patients 2 years after ACL-IB, patients 2 years after ACL reconstruction (ACL-R), and healthy controls.

MATERIALS AND METHODS

A total of 29 ACL-IB, 27 ACL-R (hamstring autograft), and 29 controls performed single-leg hop (maximum forward distance hop, SLH; side hop > 40 cm in 30 s, SH), proprioception (knee joint position sense at 30° and 60° flexion), and dynamic postural balance (Y Balance) tests. Differences were calculated within groups (side-to-side difference) and between the involved leg of patients and the non-dominant leg of controls, and were evaluated to predefined statistical (P < 0.05), clinically relevant, and methodological (smallest detectable change) thresholds. The number of exceeded thresholds represented no (0), small (1), moderate (2), or strong (3) differences. In addition, the relative number of participants achieving leg symmetry (≥ 90%) and normal performance (≥ 90% of the average performance of the non-dominant leg of controls) were compared between groups (chi-squared tests, P < 0.05).

RESULTS

We observed no-to-moderate leg differences within ACL-IB (moderate difference in hops) and within ACL-R (moderate difference in knee proprioception), no leg differences between patient groups, no-to-small leg differences between ACL-IB and controls, and no leg differences between ACL-R and controls in functional performance. However, two patients in ACL-IB and ACL-R, respectively, passed the hop pretest only with their uninvolved leg, and fewer patients after ACL-IB and ACL-R than controls reached a leg symmetry and normal leg performance of controls in SLH (P < 0.001).

CONCLUSIONS

Functional performance seems to be comparable 2 years postoperatively between ACL-IB and ACL-R for a specific subgroup of patients (i.e., proximal ACL tears, moderate activity level). However, the presumed advantage of comparable functional outcome with preserved knee structures after augmented ACL repair compared with ACL-R, and the tendency of both patient groups toward leg asymmetry and compromised single-leg hop performance in the involved legs, warrants further investigation. Level of Evidence Level III, case-control study. Trial registration clinicaltrials.gov, NCT04429165 (12/09/2020). Prospectively registered, https://clinicaltrials.gov/ct2/show/NCT04429165 .

Prospective Comparison of Postoperative Pain and Opioid Consumption Between Primary Repair and Reconstruction of the Anterior Cruciate Ligament

Background

Anterior cruciate ligament (ACL) reconstruction (ACLR) is associated with postoperative pain and necessitates using perioperative nerve blocks and multimodal analgesic plans.

Purpose

To assess postoperative pain and daily opioid use after ACL repair versus ACLR and to assess whether ACL repair could be performed successfully without using long-acting nerve blocks.

Study Design

Cohort study; Level of evidence, 2.

Methods

All eligible patients who underwent ACL surgery between 2019 and 2022 were prospectively enrolled. Patients were treated with primary repair if proximal tears with sufficient tissue quality were present; otherwise, they underwent single-bundle ACLR with either hamstring tendon or quadriceps tendon autograft. The patients were divided into 3 groups: ACLR with adductor canal nerve block (up to 20 mL of 0.25% bupivacaine with 2 mg dexamethasone), primary repair with nerve block, and primary repair without nerve block. Pain visual analog scale and number of opioids used were recorded during the first 14 postoperative days (PODs). Furthermore, patients completed the Quality of Recovery-15 (QoR-15) survey, and range of motion was assessed. Group differences were compared using Mann-Whitney U test and chi-square test.

Results

Seventy-eight patients were included: 30 (39%) underwent ACLR, 19 (24%) ACL repair with nerve block, and 29 (37%) ACL repair without nerve block. Overall, the ACL repair group used significantly fewer opioids than the ACLR group on POD 1 (1 vs 3, P = .027) and POD 2 (1 vs 3, P = .014) while also using fewer opioids in total (3 vs 8, P = .038). This difference was even more marked when only analyzing those patients who received postoperative nerve blocks (1 vs 8, P = .029). Repair patients had significantly higher QoR-15 scores throughout the first postoperative week, and they had greater range of motion (all P < .05). There were no significant differences in pain scores, opioid usage, or QoR-15 scores between patients who underwent repair with versus without nerve block.

Conclusion

The ACL repair group experienced less postoperative pain during the first 2 weeks after surgery and used significantly fewer opioids than the ACLR group. Furthermore, they had improved knee function and higher recovery quality than patients who underwent ACLR during the initial postoperative period. Postoperative nerve blocks may not be necessary after ACL repair.

Anatomic Arthroscopic Primary Repair of Proximal Anterior Cruciate Ligament Tears

Within the last decade, various highly diverse anterior cruciate ligament (ACL) preservation techniques have been proposed, as contemporary selective arthroscopic ACL preservation experienced a resurgence. Among surgical techniques, there are a variety of suturing, fixation, and augmentation methods, whereas a common thread, considering essential anatomic and biomechanical properties, is missing. This technique aims to anatomically reapproximate both the anteromedial (AM) and posterolateral (PL) bundles to their respective femoral footprints. Additionally, a PL compression stitch is performed to increase the ligament-bone contact area and recreate the anatomic vectors of the native bundles, therefore, creating a more anatomic and biomechanical construct. This technique is a minimally invasive procedure, with no graft harvesting nor tunnel drilling, which leads to decreased pain levels, earlier return of full range motion (ROM), and faster rehabilitation, while failure rates seem to be comparable to that of ACL reconstruction. We present an updated surgical technique of anatomic arthroscopic primary repair with suture anchor fixation for patients with proximal ACL tears.

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.

Is augmentation the best solution in partial anterior cruciate ligament tears? A literature systematic review and meta-analysis

Purpose

The appropriate management of partial anterior cruciate ligament (ACL) tears is still debated. There is a tendency in orthopedic clinical practice to prefer complete ACL reconstruction, while few surgeons perform ACL augmentation. The purpose of the present study is to evaluate the current evidence on the effectiveness of ACL augmentation compared with standard ACL reconstruction to assess whether ACL augmentation may be the treatment of choice in partial ACL injury.

Methods

According to PRISMA guidelines, literature research was performed in PubMed/Medline, Cochrane Library, Embase, Scopus, and Web of Science databases. A PICOS model was used, and a preliminary search resulted in 1101 articles. The methodological quality was assessed through ROBINS-I. A meta-analysis was conducted on postoperative Tegner, Lysholm scores and KT-1000 values between ACL augmentation and ACL reconstruction, and a p < 0.05 has been assumed as statistically significant. PROSPERO, ID: CRD42022343502.

Results

Seven papers were included. A total of 472 knees underwent ACL reconstruction, and 311 underwent ACL augmentation. A statistically significant discrepancy was found in the postoperative Tegner score in favor of ACL augmentation compared with ACL reconstruction (p < 0.05). Regarding the postoperative Lysholm score and KT-1000 measurement, no statistically significant difference was shown between ACL reconstruction and ACL augmentation (p > 0.05).

Conclusions

ACL augmentation has proved to be an effective and safe procedure and should be preferred to ACL reconstruction in partial ACL tears for the tendency to achieve better functional outcomes.

Age and Bone Bruise Patterns Predict Tear Location in the Anterior Cruciate Ligament

Purpose

To assess the influence of demographic risk factors, anatomic risk factors, and injury mechanisms on anterior cruciate ligament (ACL) tear patterns.

Methods

All patients undergoing knee magnetic resonance imaging at our institution for acute ACL tears (within 1 month of injury) in 2019 were retrospectively analyzed. Patients with partial ACL tears and full-thickness posterior cruciate ligament injuries were excluded. On sagittal magnetic resonance images, the proximal and distal remnant lengths were measured, and the tear location was calculated as the distal remnant length divided by the total remnant length. Previously reported demographic and anatomic risk factors associated with ACL injury were then reviewed, including the notch width index, notch angle, intercondylar notch stenosis, alpha angle, posterior tibial slope, meniscal slope, and lateral femoral condyle index. In addition, the presence and severity of bone bruises were recorded. Finally, risk factors associated with ACL tear location were further analyzed using multivariate logistic regression.

Results

A total of 254 patients (44% male patients; mean age, 34 years; age range, 9-74 years) were included, of whom 60 (24%) had a proximal ACL tear (tear at the proximal quarter). Multivariate enter logistic regression analysis showed that older age (P = .008) was predictive of a more proximal tear location whereas open physes (P = .025), bone bruises in both compartments (P = .005), and posterolateral corner injury (P = .017) decreased the likelihood of a proximal tear (R ² = 0.121, P < .001).

Conclusions

No anatomic risk factors were identified to play a role in tear location. Although most patients have midsubstance tears, proximal ACL tears were more commonly found in older patients. Bone contusions involving the medial compartment are associated with midsubstance tears; these findings may indicate that different injury mechanisms play a role in the location at which the ACL tears.

Level of Evidence

Level III, prognostic, retrospective cohort study.

Bilateral simultaneous anterior cruciate ligament tears treated with single staged simultaneous primary repair: A case report

Introduction and importance

Simultaneous bilateral anterior cruciate ligament (ACL) injuries are a rare injury pattern within the literature. There is not a consensus optimal management of this injury. Bilateral primary ACL repair in a single stage surgery provides knee stability with a minimally morbid surgery in a single rehabilitation period. This case report offers another option for surgeons to consider in the treatment of this rare injury.

Case presentation

A 45-year-old female skier presented with simultaneous bilateral isolated proximal anterior cruciate ligament injuries. MRI demonstrated bilateral proximal ACL tear patterns which were amenable to primary ACL repair. The patient subsequently underwent acute single-staged arthroscopic primary ACL repair with suture augmentation of both knees. She attained rehabilitation milestones and was fully cleared to return to sporting activities one year post-operatively. Two years post-operatively the patient continues to do well with excellent clinical outcomes.

Clinical discussion

The other treatment modalities reported in the literature were single staged and two staged ACL reconstruction with either autograft or allograft. While single staged procedures are more time and cost efficient, the primary concern is that simultaneous rehabilitation of bilateral ACL reconstructions may lead to severe quadriceps deconditioning. Primary ACL repair poses a potential solution as a minimally morbid surgery with faster rehabilitation from surgery.

Conclusion

Due to the limited invasiveness and morbidity of ACL primary repair with suture augmentation, simultaneous primary repair surgery could be an excellent treatment option for this rare patient population, saving time and cost while providing appropriate knee stability.

Level of evidence

Level IV, Case Report.

•

Single-stage bilateral ACL repair is a viable treatment option in a patient with simultaneous bilateral ACL injuries

•

ACL repair might be an excellent treatment option for this population due to its minimally morbid nature.

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Simultaneous bilateral ACL repair allows for early return to ambulation and range of motion

Primary repair with suture augmentation for proximal anterior cruciate ligament tears: A systematic review with meta-analysis

PURPOSE

To assess the outcomes of arthroscopic primary repair of proximal anterior cruciate ligament (ACL) tears with suture augmentation in the literature.

METHODS

A systematic search was performed using PubMed, EMBASE, and Cochrane for studies reporting on outcomes of primary repair of proximal ACL tears with suture augmentation between 2015 and 2021. Primary outcomes included failure and reoperation rates, whereas secondary outcomes consisted of functional outcomes. Proportion meta-analysis was performed to assess the overall incidence of failure rates. Outcomes of adults and adolescent were reported separately.

RESULTS

Thirteen studies with 418 patients were included in this study (mean age 32 years, mean follow-up 2.0 years, 49% male). There were no randomized studies and overall grade of recommendation was weak. Overall failure rate for primary repair with suture augmentation was 8% (95% CI 3.9-14.4), but this was higher for younger patients (17%; 95% CI 2.5-63.9) than for older patients (6%; 95% CI 3.8-8.9). The risk for additional reoperations, complications, or hardware removal was low (all <2%), while functional outcomes were good to excellent (all >80% of maximum score).

CONCLUSION

Current literature shows that primary repair with suture augmentation is a reliable treatment option for proximal ACL tears with a failure rate of 8% and good functional outcome scores at short-term follow-up. Although functional outcomes were good irrespective of age, failure rates were higher in young patients (17% vs 6%, respectively). There is a need for high-quality comparative studies with large group of patients to compare these outcomes with ACL reconstruction.

Primary Repair versus Reconstruction in Patients with Bilateral Anterior Cruciate Ligament Injuries: What Do Patients Prefer?

Purpose. The purpose is to evaluate knee preference and functional outcomes of patients with primary anterior cruciate ligament (ACL) repair in one knee and ACL reconstruction in the contralateral side. Methods. All patients who underwent both procedures were retrospectively reviewed at minimum two-year follow-up. Patients were asked to complete questionnaires regarding their operated knees’ preferences during rehabilitation, daily activities, sports activities, and overall function. Furthermore, the Subjective International Knee Documentation Committee, Forgotten Joint Score-12, and Anterior Cruciate Ligament-Return to Sport after Injury were completed. Results. Twenty-one patients were included. All patients underwent ACL reconstruction first, which was displayed at younger age at surgery (24 vs. 33 years, $p=0.010$ ) and longer follow-up (10.2 vs. 2.3 years, $p<0.001$ ), respectively. Thirty-three percent preferred the repaired knee, 11% the reconstructed knee, and 56% had no preference; however, 78% indicated that their repaired knee was less painful during rehabilitation and 83% reported earlier range of motion (ROM) return following repair, which was similar for both knees in 17%. Eighty-three percent of patients indicated better function and progression during rehabilitation with their repaired knee and 11% with their reconstructed knees. No statistical differences were found in patient-reported outcomes between both procedures (all $p>0.4$ ). Objective laxity assessment showed mean side-to-side difference of 0.6 mm between both sides in favor of the reconstructed knee. Conclusion. This study showed that ACL repair and ACL reconstruction lead to similar functional outcomes. However, patients undergoing both procedures may have less pain, earlier ROM return, and faster rehabilitation progression following primary repair.

Return to sports after ACL injury 5 years from now: 10 things we must do

Background

The outcome after ACL reconstruction (ACLR) is in general disappointing with unacceptable number of athletes that do not return to pre-injury level of sports, high re-injury rates, early development of osteoarthritis and shorter careers. Athletes after ACLR have high expectation to return to sports which is in contrast with the current outcomes. The aim of this manuscript is to present an overview of factors that are needed to be incorporated and to personalize the rehabilitation process for an athlete who has undergone an ACLR.

Level of evidence

4.

Acute Anterior Cruciate Ligament Rupture: Repair or Reconstruction? Five-Year Results of a Randomized Controlled Clinical Trial

BACKGROUND

High-level evidence for short-term outcomes of contemporary anterior cruciate ligament (ACL) suture repair (ACLSR) in comparison with those of ACL reconstruction (ACLR) is scarce. High-level evidence for mid- and long-term results is lacking, whereas outcomes of ACLSR in several historical studies were shown to deteriorate at midterm follow-up after initial good short-term outcomes.

HYPOTHESIS

Contemporary ACLSR is noninferior to ACLR in the treatment of acute ACL rupture in terms of patient self-reported outcomes at 5 years postoperatively.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 48 patients were enrolled in the study and, after stratification and randomization, underwent either dynamic augmented (DA) ACLSR or anatomic single-bundle ACLR. The primary outcome measure was the International Knee Documentation Committee 2000 (IKDC) subjective score (IKDCs). Furthermore, the Knee injury and Osteoarthritis Outcome Score (KOOS), Tegner Activity Scale score (TAS), visual analog scale score for satisfaction (VASs), IKDC physical examination score (IKDCpe), limb symmetry index for quadriceps (LSIq) and hamstrings (LSIh) strength and jump test battery (LSIj), Kellgren-Lawrence grade of osteoarthritis (OA), and rate of adverse events were recorded. Analyses were based on an intention-to-treat principle.

RESULTS

The lower limit of the 2-sided 95% CI for the median IKDCs of the DA ACLSR group (n = 23; 75.9) was lower than the prespecified noninferiority margin (n = 21; 86.6). Therefore, the null hypothesis was rejected. However, the upper limit of the 2-sided 95% CI of the DA ACLSR group (100.0) was higher than the median IKDCs of the ACLR group (96.6), rendering the result for noninferiority inconclusive. No statistical difference was found between groups for median IKDCs (repair, 90.2; reconstruction, 96.6). Furthermore, no statistically significant differences were found for any of the secondary outcome measures for the DA ACLSR compared with the ACLR group: KOOS Symptoms, 92.9 versus 96.4; KOOS Pain, 100 versus 97.2; KOOS Activities of Daily Living, 100 versus 100; KOOS Sport and Recreation, 85.0 versus 100; TAS score, 7.0 versus 6.5; VASs, 9.2 versus 8.7; IKDCpe, 81.8% versus 100%; LSIq, ≥91.6 versus ≥88.2; LSIh, ≥95.1 versus ≥90.7; LSIj, ≥94.2 versus ≥97.6; OA grade 0, 90.9% versus 77.8%; clinical ACL failure rate, 20.8% versus 27.2%; and repeat surgery rate, 37.5% versus 20.0%, respectively.

CONCLUSION

It remains inconclusive whether the effectiveness of DA ACLSR is noninferior to that of ACLR in terms of subjective patient-reported outcomes as measured using the IKDCs. Although DA ACLSR may be a viable treatment option for patients with acute ACL rupture, caution must be exercised when considering this treatment for young, active patients, corresponding to the present study population.

Differential regional perfusion of the human anterior cruciate ligament: quantitative magnetic resonance imaging assessment

Purpose

Surgical reconstruction is the current standard for ACL rupture treatment in active individuals. Recently, there is renewed interest in primary repair of proximal ACL tears. Despite this, ACL biology and healing potential are currently not well understood. Vascularity is paramount in ACL healing; however, previous ACL vascularity studies have been limited to qualitative histological and dissection-based techniques. The study objective was to use contrast-enhanced quantitative-MRI to compare relative perfusion of proximal, middle, and distal thirds of the in situ ACL. We hypothesized perfusion would be greatest in the proximal third.

Methods

Fourteen cadaveric knees were studied (8 females, 6 males), age 25–61 years. Superficial femoral, anterior tibial, and posterior tibial arteries were cannulated; without intraarticular dissection. Contrast-enhanced quantitative-MRI was performed using a previously established protocol. ACL regions corresponding to proximal, middle, and distal thirds were identified on sagittal-oblique pre-contrast images. Signal enhancement (normalized to tibial plateau cartilage) was quantified to represent regional perfusion as a percentage of total ACL perfusion. Comparative statistics were computed using repeated measures ANOVA, and pairwise comparisons performed using the Bonferroni method.

Results

Relative perfusion to proximal, middle, and distal ACL zones were 56.0% ±17.4%, 28.2% ±14.6%, and 15.8% ±16.3%, respectively (p = 0.002). Relative perfusion to the proximal third was significantly greater than middle (p = 0.007) and distal (p = 0.001). No statistically relevant difference in relative perfusion was found to middle and distal thirds (p = 0.281). Post-hoc subgroup analysis demonstrated greater proximal perfusion in males (66.9% ± 17.3%) than females (47.8% ± 13.0%), p = 0.036.

Conclusion

Using quantitative-MRI, in situ adult ACL demonstrated greatest relative perfusion to the proximal third, nearly 2 times greater than the middle third and 3 times greater than the distal third. Knowledge of differential ACL vascular supply is important for understanding pathogenesis of ACL injury and the process of biological healing following various forms of surgical treatment.

ACL repair for athletes?

Background

The current gold standard treatment for an anterior cruciate ligament (ACL) tear in an athlete is an arthroscopic ACL reconstruction with autografts. This restores the knee stability but is associated with unique complications like graft re-tear, kinesiophobia and graft donor site morbidity. ACL suture repair (ACLSR) is an attractive alternative method of surgical management of this injury.

Current science of ACLSR

The potential advantages of performing a repair are the preservation of native biology and proprioceptive function of ACL, elimination of a graft and preservation of bone stock. The purported benefits are better stability, reduction of kinesiophobia and faster rehabilitation. ACLSR is now performed only for proximal (femoral-sided) tears in the acute phase, when the tissue quality is good and using high-strength nonabsorbable sutures. There are several techniques for performing ACLSR but broadly speaking are either non-augmented, static augmented with suture tape, dynamic augmented or using bio-scaffolds.

Clinical outcome of ACLSR

There is a lot of literature on ACLSRs including case series, cohort studies and randomized controlled trials. The results from these studies are encouraging but mostly pertain to patient reported outcome measures, are in small numbers and in the short-term. The results are also inconsistent across different studies and not specifically performed for the athletic population. Moreover, most of these studies are from the innovator or designer surgeons and groups and have not been independently validated.

Conclusion

Currently, there is insufficient evidence to recommend ACLSR as a preferred method of managing even acute proximal tears in athletes. Improved rates of return to sports, lower retear rate and lesser kinesiophobia needs to be proven in athletes.

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.

RetroBRACE: clinical, socioeconomic and functional-biomechanical outcomes 2 years after ACL repair and InternalBrace augmentation in comparison to ACL reconstruction and healthy controls-experimental protocol of a non-randomised single-centre comparative study

INTRODUCTION

Despite good clinical outcomes reported in the literature, to date, scientific evidence for the functional and biomechanical benefit of primary anterior cruciate ligament (ACL) repair with augmentation is scarce. We present an experimental protocol for a detailed multimodal (clinical, socioeconomic, functional and biomechanical) comparative study in patients after primary ACL repair and InternalBrace augmentation, patients after ACL reconstruction and healthy controls.

METHODS AND ANALYSIS

In this non-randomised single-centre comparative study with prospective data collection with three arms (patients 2 years after ACL repair and InternalBrace augmentation; patients 2 years after ACL reconstruction using hamstring autografts; and healthy controls), 30 participants per study arm will be included. The study is designed as non-inferiority study with three arms. Required sample size was estimated based on data reported in the literature on muscle strength, proprioception and balance parameters, resulting in at least 28 participants per group. Outcome parameters include patient-reported outcome measures (EQ-5D-5L, Tegner Activity Scale, Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee and ACL-Return to Sports Injury Scale), socio-economic parameters, anterior tibial translation, range of motion and functional-biomechanical data of the lower extremities. Functional-biomechanical parameters include proprioception, isokinetic muscle strength, single-leg balance, walking, running and single-leg hops with additional lower extremity 3D joint kinematics and kinetics and muscle activity. These parameters will be compared between limbs in patients, between groups and to the current literature.

ETHICS AND DISSEMINATION

The results of this study will be disseminated through peer-reviewed publications and presentations at national and international conferences. Ethical approval was obtained by the regional ethics board (Ethics Committee Northwest Switzerland EKNZ 2020-00551), and the study is registered at clinicaltrials.gov.Trial registration numberNCT04429165.

Anterior cruciate ligament (ACL) repair using cortical or anchor fixation with suture tape augmentation vs ACL reconstruction: A comparative biomechanical analysis

BACKGROUND

The purpose was to compare knee kinematics in a cadaveric model of anterior cruciate ligament (ACL) repair using an adjustable-loop femoral cortical suspensory (AL-CSF) or independent bundle suture anchor fixation (IB-SAF) with suture tape augmentation to a bone-patellar tendon-bone (BPTB) ACL reconstruction.

METHODS

Twenty-seven cadaveric knees were randomly assigned to one of three surgical techniques: (1) ACL repair using the AL-CSF technique with suture tape augmentation, (2) ACL repair using the IB-SAF technique with suture tape augmentation, (3) ACL reconstruction using a BPTB autograft. Each specimen underwent three conditions according to the state of the ACL (native, proximal transection, repair/reconstruction) with each condition tested at four different angles of knee flexion (0°, 30°, 60°, 90°). Anterior tibial translation (ATT) and internal tibial rotation (ITR) were evaluated using 3-dimensional motion tracking software.

RESULTS

ACL transection resulted in a significant increase in ATT and ITR when compared to the native state (P < 0.001, respectively). ACL repair with the AL-CSF or IB-SAF technique as well as BPTB reconstruction restored native ATT and ITR at all tested angles of knee flexion, while showing significantly less ATT at 0°, 30°, 60°, and 90° as well as significantly less ITR at 30°, 60°, and 90° of knee flexion when compared to the ACL-deficient state. There were no significant differences in ATT and ITR between the three techniques utilized.

CONCLUSION

ACL repair using the AL-CSF or IB-SAF technique with suture tape augmentation as well as BPTB ACL reconstruction each restored native anteroposterior and rotational laxity, without significant differences in knee kinematics between the three techniques utilized.

LEVEL OF EVIDENCE

Controlled Laboratory Study.

Superb microvascular imaging (SMI) detects increased vascularity of the torn anterior cruciate ligament

PURPOSE

Ultrasound with superb microvascular imaging (SMI) is a novel microvascular imaging technology which may be useful to assess the vascularity of the torn anterior cruciate ligament (ACL) as a potential measure of healing potential following surgery. This study aimed to quantify the vascularity of the torn and intact ACL using ultrasound with SMI.

METHODS

23 patients (mean age ± standard deviation, 27.1 ± 12.8 years), who were diagnosed with an ACL tear with an intact contralateral ACL were enrolled (ACL injury group). Ten healthy volunteers (36.1 ± 4.9 years) who had intact ACLs in both knees were also recruited (ACL healthy controls). The vascularity of the ACL was assessed using SMI within 15 mm from the tibial insertion in both knees. The amount of the vascular signal was assessed using a semi-quantitative grading scale (vascularity grade: grade 0-3) and a quantified ratio of vascularized area with respect to total area of the region of interest (vascularity ratio).

RESULTS

In the ACL injury group, a significantly higher vascularity grade and ratio were observed in the torn ACL (vascularity grade 0-3: 1, 8, 7, and 7 patients, respectively; vascularity ratio: 1.3 ± 1.4%) than the contralateral intact ACL (vascularity grade 0-3: 21, 1, 1, and 0 patients, respectively; vascularity ratio: 0.1 ± 0.5%) (P < 0.001), whereas no significant difference was observed between both ACLs in the ACL healthy control group.

CONCLUSIONS

SMI was useful to assess the increased vascularity in torn ACL, which may reflect the potential for, or state of, ACL maturation following reconstruction or repair.

LEVEL OF EVIDENCE

Level III.

Distal remnant length can be measured reliably and predicts primary repair of proximal anterior cruciate ligament tears

PURPOSE

To assess the reliability and predictive value of quantifying anterior cruciate ligament (ACL) tear location on magnetic resonance imaging (MRI) and assess the predictive value of tear location on the eligibility for arthroscopic primary repair of proximal ACL tears.

METHODS

In this case-control study, all adult patients undergoing acute ACL surgery between 2008 and 2020 were retrospectively reviewed. All patients were treated with the treatment algorithm of undergoing primary repair when proximal tears with sufficient tissue quality were present intraoperatively, and otherwise underwent single-bundle ACL reconstruction. Sagittal MRI images were reviewed to measure proximal and distal remnant lengths along the anterior aspect of the torn ligament, and tear location was calculated as distal remnant divided by total remnant length. Interobserver and intraobserver reliability for remnant measurements were calculated. Then, receiver operating curve analysis (ROC) was performed to calculate the optimal cut-off for the possibility of primary repair with the different measurements.

RESULTS

Two hundred and forty-eight patients were included, of which 151 underwent repair (61%). Inter- and intraobserver reliability ranged between 0.92 and 0.96 [95% confidence interval (CI) 0.55-0.98] and 0.91-0.97 (95% CI 0.78-0.98, respectively). All patients with a tear location of  ≥ 80% on MRI could undergo repair, whereas all patients with tear location of < 60% required reconstruction. The positive predictive value of a proximal quarter tear (≥ 75%) on primary repair was 94%. Older age was correlated with more proximal tear location (p < 0.001), but there was no correlation between tear location and gender, BMI, or timing of surgery (all n.s).

CONCLUSION

This study showed that tear location could reliably be quantified on MRI by assessing distal and proximal remnant lengths. Tear location in the proximal quarter of the ACL was found to have a positive predictive value for repairability of 94%. These findings may assist orthopaedic surgeons in evaluating which patients are eligible for primary ACL repair preoperatively.

LEVEL OF EVIDENCE

III.

Primary Repair of Anterior Cruciate Ligament Injuries: Current Level of Evidence of Available Techniques

»

Recently, there has been a resurgence of interest in primary anterior cruciate ligament (ACL) repair that has the potential to preserve native tissue using a more minimally invasive approach. Multiple repair techniques for different tear types have been reported over the last decade.

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From a healing perspective, proximal tears can be reapproximated directly to the femoral wall because they have better intrinsic healing capacity than midsubstance tears. These procedures can be classified further as direct suture repair with or without static or dynamic augmentation. Current evidence does not support direct repair of midsubstance tears because of their limited healing capacity. In many instances, biological augmentation is needed to enhance the healing potential of the ACL.

»

While ACL repair is certainly not an effective surgical approach for all tears or in all patients, this procedure can be an effective and less morbid alternative to ACL reconstruction in carefully selected patients.

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The overall current reported level of evidence of published studies has ranged from low to moderate, and thus there is a need for higher-quality, comparative studies in which outcomes of larger patient groups are compared with the current gold standard of ACL reconstruction.

Arthroscopic Primary Repair of Proximal Anterior Cruciate Ligament Tears With Suture Augmentation

Background:

Historically, the midterm outcomes of open anterior cruciate ligament (ACL) repair were rather disappointing, and ACL reconstruction subsequently became the surgical standard for ACL injuries. Recent studies, however, have shown that there might be a role for arthroscopic primary repair in appropriately selected patients with proximal ACL tears.

Indications:

Due to more prominent blood supply in the proximal ligament region, ACL repair should only be performed in patients with proximal tears and good-to-excellent tissue quality. Although all patients are potential candidates, this procedure is preferably performed acutely and in adult patients.

Technique Description:

First, it is identified whether a proximal tear with good tissue quality is present. Then, both ACL bundles are sutured individually from distal to proximal using a Bunnell-type pattern and a self-retrieving suture passer. The posterolateral bundle is then reattached first in anatomical fashion, using a 4.75-mm vented biocomposite suture anchor. Next, the suture anchor of the anteromedial bundle is preloaded with an internal suture tape augmentation. After anchor deployment, the suture tape augmentation is channeled through a small 2.5-mm tibial tunnel in the anterior third of the tibial ACL footprint. Finally, the suture augmentation is tensioned near full extension and fixed to the tibia’s anteromedial cortex using single suture anchor fixation.

Results:

Recently, we have published a series of the first 113 consecutive repair patients with minimum 2-year follow-up, of which 60 received additional suture augmentation. In this cohort, the overall failure rate was 13%, which was similar to 3 other studies on modern-day ACL repair (range: 5%-15%). Subgroup analysis showed that the failure rate was much higher in patients ≤21 years (38%) but low in patients >21 years (0%). Finally, it has been shown that there is an earlier return of knee motion, complications are rare, and there is less joint awareness after ACL repair as compared with ACL reconstruction.

Conclusion:

Selective, modern-day, arthroscopic primary ACL repair with suture augmentation seems to be a good alternative to ACL reconstruction in carefully selected patients, which include patients with proximal tears and good tissue quality and aged ≥22 years.

Editorial Commentary: Anterior Cruciate Ligament Suture Repair Could Have High Failure Rates in Active Athletes of All Ages

When it comes to anterior cruciate ligament (ACL) injury and surgery, age is a proxy for early return to strenuous sports. In addition, premature return to sport is a risk factor for reinjury after ACL surgery. Thus, when considering ACL suture repair as an alternative to ACL graft reconstruction, we must consider that failure rates may be influenced by patient demographic variables, particularly age and activity. In the end, treatment options for young patients who are highly active and eager to make a timely return to sport after ACL injury require careful evaluation.

Role of Age on Success of Arthroscopic Primary Repair of Proximal Anterior Cruciate Ligament Tears

PURPOSE

To assess failure rates and patient-reported outcomes measures following arthroscopic primary anterior cruciate ligament (ACL) repair of proximal tears in different age groups.

METHODS

Between 2008 and 2017, the first 113 consecutive patients treated with repair were retrospectively reviewed at minimum of 2 years. Patients were stratified into 3 age groups: ≤21, 22-35, and >35 years. Primary outcomes were ipsilateral reinjury or reoperation, and contralateral injury rates, and secondary outcomes consisted of Lysholm, modified Cincinnati, Single Assessment Numeric Evaluation, International Knee Documentation Committee subjective, pain, and satisfaction scores. Group differences were compared using χ² tests and Mann-Whitney U tests.

RESULTS

Follow-up was obtained in 113 patients (100%). Median age was 35 years (interquartile range [IQR] 23-43) and median follow-up was 2.2 years (IQR 2.0-2.8). Overall, ACL reinjury occurred in 13 patients (11.5%), reoperation in 7 patients (6.2%), complications in 2 patients (1.8%) and contralateral ACL injury in 4 patients (3.5%). Overall, median Lysholm was 95 (IQR 89-100) and International Knee Documentation Committee subjective 92 (IQR 84-99). Treatment failure was significantly greater in the youngest age group (37.0%) as compared with the middle and older groups (4.2% and 3.2%, both P < .005). No significant differences were seen in reoperation, complication, or contralateral injury rates between groups (all P > .2), nor in patient-reported outcomes measures between the groups (all P > .1).

CONCLUSIONS

The failure rate of primary repair of proximal ACL tears is high in patients aged 21 or younger (37.0%), and this should be taken into account when discussing repair in this patient group. In patients older than 21, repair may be an excellent treatment with low failure (3.5%) and complication rates (1.2%) and good subjective scores.

LEVEL OF EVIDENCE

Level III, retrospective comparative therapeutic trial.

Standard MRI May Not Predict Specific Acute Anterior Cruciate Ligament Rupture Characteristics

Background

There has been renewed interest in the concept of anterior cruciate ligament (ACL) suture repair (ACLSR). Morphologic characteristics of the ruptured ACL remnant play a role in deciding whether a patient is eligible for ACLSR. However, no classification of these characteristics of ACL rupture on magnetic resonance imaging (MRI) scans has yet been compared with intraoperative findings in the context of ACLSR.

Purpose

To investigate the value of using preoperative MRI to predict specific characteristics of acute complete ACL rupture.

Study Design

Cohort study (diagnostic); Level of evidence, 2.

Methods

A total of 25 patients were included. Two radiologists classified ACL rupture location and pattern on preoperative 1.5-T MRI scans with a standard sequence; the results were compared with the corresponding findings at arthroscopy conducted by a single surgeon. The agreement between the MRI and surgical findings was calculated using Cohen κ values. Furthermore, the reliability coefficients of the MRI classifications within and between radiologists were calculated.

Results

The agreement between MRI classification and arthroscopic findings for ACL rupture location was slight (Cohen κ, 0.016 [radiologist 1] and 0.087 [radiologist 2]), and for ACL rupture pattern, this was poor to slight (Cohen κ, <0 and 0.074). The intraobserver reliability of MRI classification for ACL rupture location was moderate for radiologist 1 and slight for radiologist 2 (Cohen κ, 0.526 and 0.061, respectively), and for ACL rupture pattern, this was slight for radiologist 1 and 2 (Cohen κ, 0.051 and 0.093, respectively). The interobserver reliability of MRI classification for ACL rupture location and pattern was slight between radiologists (Cohen κ, 0.172 and 0.040, respectively).

Conclusion

In the current study, we found poor to slight agreement between MRI classification and arthroscopic findings of specific ACL rupture characteristics. In addition, the intra- and interobserver reliability for MRI classification of the ACL rupture characteristics was slight to moderate.

Acute and delayed anterior cruciate ligament repair results in similar short to mid-term outcomes

BACKGROUND

To assess whether primary repair of proximal ACL tears in the delayed setting leads to similar clinical and functional outcomes as compared to ACL repair in the acute setting.

METHODS

All patients with proximal tears with good tissue quality treated in the acute (≤3 weeks post-injury) and delayed setting (>3 months post-injury) were retrospectively reviewed at minimum 2-year follow-up. Ipsilateral reinjury or reoperation and contralateral injury rates were recorded. Functional outcomes were evaluated using the Lysholm, modified Cincinnati, Single Assessment Numeric Evaluation, International Knee Documentation Committee subjective, Forgotten Joint Score-12, Anterior Cruciate Ligament-Return to Sport after Injury scale, and satisfaction scores. Finally, time to return to work, time to discontinue brace-usage, time to running, and time to return to sports were reviewed. Group differences were compared using chi-square tests and Mann-Whitney U tests.

RESULTS

Sixty-nine patients were included, of which 34 (49%) were treated acutely and 35 (51%) in the delayed setting. Besides time from injury to surgery, patient demographics were similar between groups (all p > 0.1). There were three reinjuries (9%) in the acute group and four in the delayed (11%; p > 0.999). Reoperation, complication, and contralateral injury rates were similar between groups (all p > 0.1), while functional outcomes were also comparable (all p > 0.05).

CONCLUSION

This study found that acute and delayed primary ACL repair results in similar clinical and functional outcomes at short to mid-term follow-up. Therefore, the most important factors for repair surgery success seem to be tissue quality and tissue length, rather than acuity of the surgery.

LEVEL OF EVIDENCE

Level III, retrospective comparative cohort study.

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

Until the past decade the common thought was that the anterior cruciate ligament (ACL) was not able to heal and restore knee stability. In this manuscript a brief review of studies of the developers and the early adaptors of four different modern ACL repair techniques are presented. The present status and considerations for the future of ACL repair and its research are shared. After promising short- to midterm ACL healing results by the developers, the results of the early adaptors show more variety in terms of rerupture and reintervention for other reasons. Risk factors for failure are a young age, high preinjury sports activity level, midsubstance ruptures and impaired integrity of the ACL bundles and the synovial sheath. There is a call for more clinical data and randomized clinical trials. Conclusion: an important finding of the past decade is that the ACL is able to heal and subsequently restabilize the knee. Patient selection is emphasized: the ideal patient is a non-high athlete older than 25 and has an acute proximal one bundle ACL rupture. Further research will have to show if ACL repair could be a game changer or if history will repeat itself.

Large variation in indications, preferred surgical technique and rehabilitation protocol for primary anterior cruciate ligament repair: a survey among ESSKA members

PURPOSE

To assess current surgical preferences and practice patterns regarding primary anterior cruciate ligament (ACL) repair among European Society for Sports Traumatology, Knee Surgery and Arthroscopy (ESSKA) members.

METHODS

A web-based survey was designed, including questions regarding indications for primary repair, outcomes of primary repair, and rehabilitation protocols. An invitation for study participation was sent by email to all ESSKA e-mail contacts. Descriptive statistics were performed.

RESULTS

A total of 169 surgeons responded to the survey (7% response rate of active members). Lack of supporting scientific evidence is the main reason for not using repair as a surgical treatment (63%). Most important indications were proximal avulsion tears (84%), younger age (49%), and older age (34%). Among those currently utilizing repair as a treatment option, transosseous tunnel fixation repair (34%) and repair with internal brace using transosseous tunnel fixation (32%) were the most preferred techniques. Eleven percent indicated dynamic intraligamentary stabilization as their preferred technique. A similar rate of progression for rehabilitation for repair and reconstruction techniques was noted among respondents.

CONCLUSION

This practice survey shows that the majority of surgeons indicated the main reason for not incorporating primary repair in their current practices was a lack of supporting scientific evidence. Among those holding favourable attitudes and beliefs, most surgeons indicated patients with proximal tears, younger-aged, and older-aged patients might be eligible for repair. Prospective studies with higher levels of evidence are warranted to establish guidelines for repair, including indications, optimal surgical technique, and rehabilitation protocols.

LEVEL OF EVIDENCE

V (expert opinion).

Good to Excellent Functional Short-Term Outcome and Low Revision Rates Following Primary Anterior Cruciate Ligament Repair Using Suture Augmentation

The aim of this study was to evaluate the functional outcome of primary anterior cruciate ligament (ACL) repair using suture augmentation (SA) in 93 consecutive patients (67 female) with a minimum follow-up of 12 months. Patients’ outcomes were determined using International Knee Documentation Committee (IKDC) score, Lysholm score (LS) and Tegner score (TS). Knee-laxity was assessed using the KT-1000 arthrometer. Eighty-eight patients (67 female, mean age 42 years ± standard deviation (SD) 13) were available for follow-up after a mean time of 21 months (range 12–39). Three patients (3%) underwent revision surgery and were excluded from functional analysis. The mean IKDC score was 87.4 ± 11, mean LS was 92.6 ± 11, mean pre-traumatic TS was 6 ± 2 and mean postoperative TS was 6 ± 2, with a mean difference (TS_Diff) of 1 ± 1. The interval from injury to surgery had no significant impact on the postoperative IKDC (p = 0.228), LS (p = 0.377) and TS_Diff (p = 0.572). Patients’ age (>40 years), BMI (>30) and coexisting ligament or meniscal injuries did not seem to influence postoperative functional results. Primary ACL repair using SA provides good to excellent functional outcomes with a low probability of revision surgery at a minimum of 12 months.