Paediatric ACL repair reinforced with temporary internal bracing

Primary ACL repair in a selected patient cohort: A prospective single cohort study

Background

Anterior cruciate ligament (ACL) tears are common knee injuries, particularly in physically active individuals. While ACL reconstruction (ACL-R) is the standard treatment, it has notable limitations. Recent interest in primary ACL repair offers a potential alternative, especially for specific tear types and patient demographics.

Purpose

To evaluate the outcomes of primary ACL repair in a selected patient cohort with strict inclusion and exclusion criteria, focusing on the survival of the procedure, functional outcomes, and factors influencing success rates.

Methods

This prospective single cohort study included 61 patients who underwent primary ACL repair between June 2016 and June 2022. Patients were 50 years or younger, with recent ACL injuries and no previous knee surgeries or multiligament injuries. The primary outcomes were the survival of the repair beyond two years, measured by revision rates, and functional outcomes assessed using the Lysholm knee score, Tegner activity scale, and Lachmeter stability measurements.

Results

Fifty-four patients completed a minimum follow-up of three years (average 49.6 months). The overall success rate was 82.2 %, with Sherman type 1 tears showing significantly fewer failures compared to type 2 (4.3 % vs. 31.8 %). The mean Lysholm score for successful repairs was 96, and the Tegner score dropped from a pre-injury average of 6 to 5. Adolescents had the highest failure rate (50 %), while other age groups showed better outcomes. The mean side-to-side difference in stability was 1.4 mm, favoring the control side.

Conclusion

Primary ACL repair is a viable option for selected patients, particularly those with Sherman type 1 tears. While age and tear type significantly affect outcomes, the procedure shows promising results with high functional scores in successful repairs. Further research with larger cohorts and extended follow-ups is necessary to validate these findings and refine patient selection criteria. Primary ACL repair offers a less invasive alternative to ACL reconstruction, with potential for comparable outcome.

Outcomes of multiligament knee injury treated with versus without internal brace suture augmentation

PURPOSE

To compare the postoperative outcomes between Internal Brace (IB) and non-IB patients who underwent surgical management of multiple-ligament knee injuries (MLKI).

METHODS

Patients who underwent surgical management of MLKI at two institutions between 2010 and 2020 were identified and offered participation in the study via the collection of postoperative functional outcomes for MLKI; Lysholm Knee score, Multiligament Quality of Life (ML-QOL), Patient-Reported Outcomes Measurement Information System (PROMIS) computer adaptive testing (CAT), Pain Interference (PI), Physical Function (PF), and Mobility instruments (MI). The postoperative outcomes and reoperation rates were compared between the IB group and non-IB group.

RESULTS

One hundred and twenty-six patients were analyzed; 89 were included in the IB group (31.5% female; age 35.6 ± 1.4 years), and 37 were included in the non-IB group (25.7% female; age 38.8 ± 2.4 years). Mean follow-up time of the entire cohort was 37.9 ± 4.7 months [IB: 21.8 + 1.63; non-IB: 76.4 ± 6.2, p < 0.001). The IB group achieved similar PROMIS CAT [PROMIS Pain (51.8 + 1.1 vs. 52.1 + 1.6, p = 0.8736), Physical Function (46.6 + 1.2 vs. 46.4 + 1.8, p = 0.9168), Mobility (46.0 + 1.0 vs. 43.7 + 1.6, p = 0.2185)], ML-QOL [ML-QOL Physical Impairment (36.6 + 2.5 vs. 43.5 ± 4.2, p = 0.1485), Emotional Impairment (42.5 + 2.9 vs. 48.6 ± 4.6, p = 0.2695), Activity Limitation (34.5 + 2.8 vs. 36.2 ± 4.3, p = 0.7384), Societal Involvement (39.1 + 3.0 vs. 41.7 + 4.2, p = 0.6434)] and Lysholm knee score (64.9 + 2.5 vs. 60.4 + 4.0, p = 0.3397) postoperatively compared the non-IB group, but the differences were not significant.

CONCLUSION

In this cohort of patients with MLKI treated with versus without IB, outcomes and reoperation rates trended toward favoring IB, but the study was not sufficiently powered to reach statistical significance. Internal bracing could be useful in the management of MLKI. In the future, matched patient cohorts with more patients are warranted to further evaluate the clinical impact of the internal brace in MLKI.

Functional Rehabilitation of Anterior Cruciate Ligament Tear in the Pediatric Population: A Comprehensive Review

Pediatric sports injuries are a growing concern due to increased youth participation in sports. Effective rehabilitation strategies are essential for ensuring optimal recovery, restoring knee function, and preventing long-term consequences. This research aims to explore and evaluate various functional rehabilitation approaches tailored to pediatric anterior cruciate ligament (ACL) tear injuries. Functional rehabilitation of ACL tears in pediatric sports injuries is an important area of research due to the unique considerations and challenges that arise when treating ACL injuries in young athletes. Over the last 20 years, there has been a well-documented uptick in ACL injuries among pediatric populations. This rise can be attributed to the growing involvement of the younger population in competitive sports, as well as heightened awareness regarding sports-linked injuries. This study highlights the importance of early surgical reconstruction in children to enable a quick return to sports and prevent long-term cartilage and meniscal damage resulting from instability. The use of physeal-sparing ACL reconstruction techniques, particularly hamstring autografts, is recommended for favorable clinical outcomes while minimizing growth disturbances. This study offers valuable insights for healthcare professionals and researchers, serving as a reference to guide optimal approaches in managing pediatric ACL injuries and achieving successful results in this field.

Clinical and Patient-Reported Functional Outcome of Semitendinosus Autograft Anterior Cruciate Ligament Reconstruction With FiberTape® InternalBrace™ All-Inside Technique: A Prospective Study

AIM

The purpose of this study is to report the early one-year clinical and patient-reported functional outcomes of semitendinosus autograft anterior cruciate ligament reconstruction with the FiberTape® InternalBrace™ all-inside technique.

MATERIALS AND METHODS

The patient-reported functional outcomes and clinical outcomes were analyzed prospectively following the treatment of 324 unilateral ACL rupture cases with the FiberTape® InternalBrace™ Technique. Patient-reported outcome measures (KOOS scores, WOMAC scores, VAS score, and IKDC score) and clinical examinations like pre-operative and post-operative pivot shift, Lachman test, and range of motion (ROM) were conducted. These tests and examinations were recorded for each patient before surgery and at 3, 6, and 12 months after surgery. Secondary outcomes like re-rupture, infection, synovitis, or limited range of motion were noted. The mean follow-up period was 18±4.5 months (range: 12-24 months).

RESULTS

Out of a total of 324 cases, 37 cases (11.4%) could not be followed up. 158 patients (55.1%) were male and 129 were female (44.9%). Preoperative mean KOOS pain value, KOOS symptoms, KOOS ADLs, KOOS sport and recreation, and KOOS quality of life were 77.05, 78.69, 84, 21, 89.7, and 57, respectively. All KOOS subsections increased significantly at one-year to 98.37, 99.09, 98.95, 99.02, and 99.30 (p<0.0001), respectively. Mean preoperative WOMAC pain, WOMAC stiffness, and WOMAC function were 76.4, 65.2, and 74.1 and increased significantly at one-year to 94.5, 89.6, and 98.2 (p<0.0001), respectively. There was a significant decrease in VAS for pain from 2.93 before surgery to 0.12 (p<0.0001) at one year. The IKDC score significantly changed from a pre-treatment value of 50.9 to 96.2 (94.5-97.8) at a follow-up of one year. The Lysholm score at 12-months was significant at 95 (93.1-96.9), p<0.05. Post-operative Lachman test values decreased significantly, which meant decreased laxity, from 1.98 (1.89-2.07) pre-operative to 1.60 (1.57-1.62) p<0.05 at one-year post-operative. At one-year follow-up, 276 patients (96%) had fully recovered.

CONCLUSION

It was concluded that the FiberTape® InternalBrace™ technique for ACL reconstruction provides orthopedic surgeons with an effective alternative technique to conventional methods of surgery and also reduces the overall time to recovery for patients, thereby allowing them to return to sports faster.

LEVEL OF EVIDENCE

Level 4.

Cohort study of short-term outcomes after ACL-reconstruction using autograft with internal brace reinforcement versus isolated autograft demonstrating no significant difference

Background

The gold standard treatment for Anterior Cruciate Ligament injury is reconstruction (ACL-R). Graft failure is the concern and ensuring a durable initial graft with rapid integration is crucial. Graft augmentation with implantable devices (internal brace reinforcement) is a technique purported to reduce the risk of rupture and hasten recovery. Few studies have examined these techniques, in particular when compared to non-augmented grafts. This study assesses the short-term outcome of ACL-R using augmented and non-augmented hamstring tendon autografts.

Methods

This was a retrospective cohort study comparing augmented and non-augmented ACL-R. All procedures were performed in a single centre using the same technique. The Knee injury and Osteoarthritis Outcome Score [KOOS] was used to assess patient-reported outcomes.

Results

There were 70 patients in the augmented and 111 patients in the control group. Mean graft diameter in the augmented group was 8.82 mm versus 8.44 mm in the non-augmented. Six strand graft was achievable in 73.5% of the augmented group compared to 33% in the non-augmented group. Two graft failures were reported in the non-augmented group and none in the augmented group. Patient satisfaction rates were higher in the augmented group. There was a statistically insignificant improvement in the postoperative KOOS in the augmented group compared to the non-augmented group (p 0.6). Irrespective of augmentation status, no correlation was found between the functional score and age, or femoral tunnel width.

Conclusion

No statistically significant difference was demonstrated in the short-term functional outcome of ACL reconstruction using an augmented or non-augmented hamstring graft. Augmented ACL-R may achieve superior graft diameters, failure rates and patient reported outcomes when compared to nonaugmented ACL-R. Prospective trials are needed to examine this further.

All-Epiphyseal Anterior Cruciate Ligament Repair Using Suture Ring Device in the Skeletally Immature Patient

Anterior cruciate ligament (ACL) tears in pediatric patients pose distinct challenges in management, especially in patients with open distal femoral and proximal tibial physes. There are a variety of contemporary reconstruction techniques that attempt to address these challenges. However, with the resurgence of ACL repair in the adult population, it has become apparent that the pediatric patient may also benefit from primary ACL repair rather than reconstruction. ACL repair is a procedure performed to treat ACL tears that avoids the donor-site morbidity seen with ACL reconstruction using autograft. We describe a surgical technique involving FiberRing sutures (Arthrex, Naples, FL) and TightRope-internal brace fixation (Arthrex) for ACL repair with all-epiphyseal fixation in the pediatric patient. The FiberRing is a knotless, tensionable suture device that can be used to stitch the torn ACL and coupled with the TightRope and internal brace to fix the ACL.

Augmenting ACL Repair With Suture Tape Improves Knee Laxity: A Biomechanical Study

Background

Anterior cruciate ligament (ACL) repair is an alternative to reconstruction; however, suture tape support may be necessary to achieve adequate outcomes.

Purposes

To investigate the influence of suture tape augmentation (STA) of proximal ACL repair on knee kinematics and to evaluate the effect of the 2 flexion angles of suture tape fixation.

Study Design

Controlled laboratory study.

Methods

Fourteen cadaveric knees were tested using a 6 degrees of freedom robotic testing system under anterior tibial (AT) load, simulated pivot-shift (PS) load, and internal rotation (IR) and external rotation loads. Kinematics and in situ tissue forces were evaluated. Knee states tested were (1) ACL intact, (2) ACL cut, (3) ACL repair with suture only, (4) ACL repair with STA fixed at 0° of knee flexion, and (5) ACL repair with STA fixed at 20° of knee flexion.

Results

ACL repair alone did not restore the intact ACL AT translation at 0°, 15°, 30°, or 60° of flexion. Adding suture tape to the repair significantly decreased AT translation at 0°, 15°, and 30° of knee flexion but not to the level of the intact ACL. With PS and IR loadings, only ACL repair with STA fixed at 20° of flexion was not significantly different from the intact state at all knee flexion angles. ACL suture repair had significantly lower in situ forces than the intact ACL with AT, PS, and IR loadings. With AT, PS, and IR loadings, adding suture tape significantly increased the in situ force in the repaired ACL at all knee flexion angles to become closer to that of the intact ACL state.

Conclusion

For complete proximal ACL tears, suture repair alone did not restore normal knee laxity or normal ACL in situ force. However, adding suture tape to augment the repair resulted in knee laxity closer to that of the intact ACL. STA with fixation at 20° of knee flexion was superior to fixation with the knee in full extension.

Clinical Relevance

The study findings suggest that ACL repair with STA fixed at 20° could be considered in the treatment of femoral sided ACL tears in the appropriate patient population.

Suture Augmentation in Orthopaedic Surgery Offers Improved Time-Zero Biomechanics and Promising Short-Term Clinical Outcomes

Ligament and tendon ruptures have historically been addressed with varying techniques involving either repair or reconstruction. More recently, the potential biomechanical benefits of suture augmentation (SA), also known as internal brace, have attracted substantial attention and helped renew interest in ligament repair surgery. We evaluated the biomechanical and clinical outcomes of SA-based techniques in the following sports medicine procedures: medial ulnar collateral ligament repair of the elbow, thumb collateral ligament repair, anterior cruciate ligament repair, Achilles' tendon repair, and deltoid ligament repair. Published data on the use of SA to augment repairs of the ulnar collateral ligament, thumb collateral ligament, anterior cruciate ligament, Achilles' tendon, and deltoid ligament repair demonstrates improved time-zero biomechanical and promising short to mid-term clinical outcomes. However, surgeons must be wary of potential complications, including joint over-constraint, nerve paresthesia, and infection.

Current strategies for enhancement of the bioactivity of artificial ligaments: A mini-review

Background and objective

Anterior cruciate ligament (ACL) reconstruction calls for artificial ligaments with better bioactivity, however systematic reviews regarding bioactivity enhancement strategies, technologies, and perspectives of artificial ligaments have been rarely found.

Methods

Research papers, reviews, and clinical reports related to artificial ligaments were searched and summarized the current status and research trends of artificial ligaments through a systematic analysis.

Results

Having experienced ups and downs since the very first record of clinical application, artificial ligaments differing in material, and fabrication methods have been reported with different clinical performances. Various manufacturing technologies have developed and realized scaffold- and cell-based strategies. Despite encouraging in-vivo and in-vitro test results, the clinical results of such new designs need further clinical examinations.

Conclusion

As the demand for ACL reconstruction dramatically increases, novel artificial ligaments with better osteoinductivity and mechanical performance are promising.

The translational potential of this article

To develop novel artificial ligaments simultaneously possessing excellent osteoinductivity and satisfactory mechanical performance, it is important to grab a glance at recent research advances. This systematic analysis provides researchers and clinicians with comprehensive and comparable information on artificial ligaments, thus being of clinical translational significance.

The Chinese knotting technique assist anatomical anterior cruciate ligament reconstruction for aggressive rehabilitation

Aggressive rehabilitation after anterior cruciate ligament (ACL) reconstruction may result in better clinical outcomes and fewer complications such as knee stiffness and weakness. We explored the effect of the Chinese knotting technique (CKT) for aggressive rehabilitation after ACL reconstruction. Ninety-one anatomical ACL reconstruction cases from 2016 to 2020 were retrospectively reviewed. All patients were operated by the same senior physician and his team. According to the reconstruction with or without CKT, the patients were divided into 2 groups. Both groups received aggressive rehabilitation. The follow-up time of 91 patients was more than 2 years. In total, 43 out of the 91 patients were in the CKT group, and 48 were in the routine group. The knee joint kinematics recorded by Opti_Knee revealed no significant difference among the CKT group, the routine group, and healthy adults at 3, 6, 12, and 24 months after the operation, respectively. The internal and external rotation angle and the anteroposterior displacement at 3 and 6 months after the operation in the CKT group were smaller than in the routine group and were similar to that of the healthy adults. There was no significant difference in flexion and extension angle, varus or valgus angle, proximal-distal displacement, or the internal or external displacement between the 2 groups. In addition, there was no significant difference in 6 degrees of freedom of the knee between the 2 groups at 12 and 24 months after the operation, respectively, which was similar to healthy adults. Compared to the routine group, the International Knee Documentation Committee scores were significantly higher in the CKT group at the 3, 6, and 12 months, respectively, but no difference was observed at 24 months (P = .749). The Lysholm score was significantly higher in the CKT group at the 3 and 6 months postoperatively, while there was no difference at 12 and 24 months, respectively. In short-term observation, the ACL reconstruction with CKT, which can sustain aggressive rehabilitation and prevent the loosening of ACL graft, can lead to better clinical outcomes and kinematics recovery of the knee compared to routine technique.

Biomechanical Evaluation of Suture Tape Internal Brace Reinforcement of Soft Tissue Allografts for ACL Reconstruction Using a Porcine Model

Background:

Internal bracing of anterior cruciate ligament (ACL) surgery is a newer concept gaining popularity.

Purpose/Hypothesis:

To assess the biomechanical performance of soft tissue ACL reconstruction allografts reinforced with suture tape. It was hypothesized that load to failure would increase and cyclic displacement would decrease at time zero in the constructs reinforced with internal brace suture tape compared with those without suture tape augmentation.

Study Design:

Controlled laboratory study.

Methods:

We performed ACL reconstruction on porcine knees using bovine extensor tendon soft tissue allografts: 10 knees without (control) and 10 knees with (reinforced) suture tape reinforcement. An all-inside reconstruction technique was utilized with retrograde tunnel creation. An adjustable-loop device was used for femoral and tibial fixation of all grafts. The suture tape was placed through the tension loop in the femoral fixation construct and independently fixed in the tibia with an interference screw anchor. For each specimen, the authors recorded ultimate load, yield load, stiffness, cyclic displacement, and mode of failure. Outcomes between groups were compared using the Student t test.

Results:

There was a 33% decrease in mean cyclic displacement in the specimens with reinforced grafts (reinforced vs control: 3.9 ± 0.7 vs 5.8 ± 1.5 mm; P = .001). The reinforced grafts also had a 22% higher mean ultimate load (921 ± 180 vs 717 ± 122 N; P = .008) and a 25% higher mean yield load (808 ± 201 vs 602 ± 155 N; P = .020). There was no significant difference in stiffness between the reinforced versus nonreinforced grafts (136 ± 16 vs 132 ± 18 N/mm; P = .617). Three of the 10 control specimens failed at the graft, compared with 1 of 10 reinforced grafts. All other constructs in both groups failed at the tibial fixation site.

Conclusion:

Suture tape reinforcement of soft tissue grafts significantly decreased cyclic displacement while significantly increasing ultimate and yield loads without increasing graft construct stiffness during biomechanical testing at time zero in a porcine animal model.

Clinical Relevance:

The improved biomechanical performance of suture tape–reinforced graft constructs could allow patients to participate in earlier advancement of aggressive rehabilitation and potentially reduce failure rates as graft remodeling progresses.

Paediatric Anterior Cruciate Ligament (ACL) Injuries: Current Concepts Review

BACKGROUND

Over the past two decades, there has been a documented increase in paediatric ACL injuries because of a rise in younger age sports participation at the competitive level, awareness about sports-related injuries, and advanced imaging modalities.

METHODS

A PubMed electronic database search was done, which revealed 1366 hits over the last five years (2016 - 2020). Finally, 37 articles that contributed to new findings were included. This review was conducted based on predefined research questions.

RESULTS AND CONCLUSION

Early surgical reconstruction is recommended in children due to the increasing demand for early return to sports and to prevent the instability that can lead to progressive cartilage and meniscal damage. With the evolution of several "physeal sparing" ACL reconstruction (ACLR) techniques, a favorable clinical outcome with less growth disturbance is achievable. Although different autograft options are available, hamstring autografts are most commonly preferred. A specific pattern of a bone bruise not extending into the metaphysis, and lateral meniscus tears are the most common associated injuries. Following paediatric ACLR, complications like graft rupture and contralateral ACL injuries are two to three folds higher than with adult ACLR. Unprepared early return to sports is one of the reasons for increased complication rates in children; thus, clearance criteria for return to sports need to be standardized, and early return to sports (< 9 months post ACLR) should be avoided. Neuromuscular training protocols are recommended to minimize complications like graft ruptures.

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.

Treatment of knee sprains in children

The incidence of knee sprains in children is steadily increasing. Skeletal immaturity and anatomical features of the child's ligamentous structures explain the frequency of bone avulsions in young children. Peripheral ligament injuries are the most common and often benign. Nevertheless, associated injuries of the cruciate or patellofemoral ligament(s) are not rare and must not be missed. Age is a determining factor in diagnostic guidance. Anterior intercondylar tibial eminence fractures, otherwise known as tibial spine fractures (TSF), usually occur in young children. Ligamentous distension at the time of the accident would explain the residual laxity that can affect the prognosis of these fractures. The treatment of interstitial ruptures of the ACL follows recommendations that are becoming clearer through multicentric studies. Reparation techniques, historically rejected as ineffective, have again become topical under specific conditions with the aim of preserving the native ACL and its proprioceptive receptors, which are essential in children. ACL reconstruction techniques have made progress in children, especially with techniques adapted from adults. Preservation of growth plates remains pertinent, especially at the femur to avoid growth disorders, thus highlighting the important role paediatric orthopaedic surgeons have in the management of these knee sprains.

Independent Suture Augmentation With All-Inside Anterior Cruciate Ligament Reconstruction Reduces Peak Loads on Soft-Tissue Graft. A Biomechanical Full-Construct Study

PURPOSE

To evaluate the effect of suture augmentation (SA) of 7-mm and 9-mm diameter graft on load sharing, elongation, stiffness, and load to failure for all-inside anterior cruciate ligament reconstruction (ACLR) in a biomechanical Study was funded by Arthrex ID: EMEA-16020. full-construct porcine model.

METHODS

Bovine tendon grafts, 7-mm and 9-mm diameter, with and without SA were tested using suspensory fixation (n = 8). The independent SA was looped over a femoral button and knotted on a tibial button. Preconditioned constructs were incrementally increased loaded (100N/1,000 cycles) from 100N to 400N for 4,000 cycles (0.75 Hz) with final pull to failure (50 mm/min). Isolated mechanical and optical measurements during construct loading of the SA allowed to quantify the load and elongation range during load sharing. Construct elongation, stiffness and ultimate strength were further assessed.

RESULTS

Load sharing in 7-mm grafts started earlier (200N) with a significant greater content than 9-mm grafts (300N) to transfer 31% (125N) and 20% (80N) of the final load (400N) over the SA. Peak load sharing with SA reduced total elongation for 7-mm (1.90 ± 0.27 mm vs 4.77 ± 1.08 mm, P < .001) and 9-mm grafts (1.50 ± 0.33 mm vs 3.57 ± 0.54 mm, P < .001) and adequately increased stiffness of 7-mm (113.4 ± 9.3 N/mm vs 195.9 ± 9.8 N/mm, P < .001) to the level of augmented 9-mm grafts (208.9 ± 13.7N/mm). Augmentation of 7-mm (835 ± 92N vs 1,435 ± 228N, P < .001) and 9-mm grafts (1,044 ± 49N vs 1,806 ± 157N, P < .001) significantly increased failure loads.

CONCLUSIONS

Load sharing with SA occurred earlier (200N vs 300N) in lower stiffness 7-mm grafts to carry 31% (7-mm) and 20% (9-mm) of the final load (400N). Loads until peak load sharing were transferred over the graft. Augmented constructs showed significantly lower construct elongation and increased stiffness without significance between variable grafts. Failure load of augmented grafts were significantly increased.

CLINICAL RELEVANCE

Suture tape ligament augmentation may potentially protect biological grafts from excessive peak loading and elongation, thus reducing the risk of graft tears.

All-Inside Anterior Cruciate Ligament Reconstruction with Suture Tape Augmentation: Button Tie-Over Technique (BTOT)

The anterior cruciate ligament (ACL) is the most common ligamentous knee injury in pivoting sports. There are multiple techniques described for ACL reconstruction; however, still there is an ongoing debate regarding the optimal technique with minimal residual laxity and least risk of rerupture. All-inside ACL reconstruction with suture tape augmentation (InternalBrace) is a newly developed method of ACL reconstruction to help address these issues. Suture tape protects the graft during ligamentization process. The aim of this article is to describe a modified all-inside ACL reconstruction technique with suture tape augmentation in which the internal brace is tied distally over the distal TightRope button without an extra method of fixation.

Suture Tape Augmentation Improves the Biomechanical Performance of Bone-Patellar Tendon-Bone Grafts Used for Anterior Cruciate Ligament Reconstruction

PURPOSE

The purpose of this study was to investigate the time-zero biomechanical properties (stiffness, displacement, and load at failure) of bone-patellar tendon-bone (BTB) grafts used for anterior cruciate ligament (ACL) reconstruction with and without suture tape augmentation as a means to determine the potential clinical benefit of this technique.

METHODS

Eight juvenile porcine knees underwent ACL reconstruction with a human cadaveric BTB graft (control). These were compared to 8 juvenile porcine knees that underwent ACL reconstruction with a BTB graft augmented with suture tape. All knees underwent biomechanical testing utilizing a dynamic tensile testing machine. Cyclic loading between 50-250N was performed for 500 cycles at 1 Hz to simulate in vivo ACL loads during the early rehabilitation phase. The grafts were displaced during load-at-failure tensile testing at 20 mm/min. Differences in graft displacement, stiffness, and load at failure for the control and suture tape augmented groups were compared with the Student t-test with a significance level of P < .05.

RESULTS

There was no difference in graft displacement between the 2 groups. A 104% higher postcyclic stiffness was noted in the augmented group compared to the controls (augmentation: 261 ± 76 N/mm versus control 128 ± 28 N/mm, P = .002). The mean ultimate load at failure was 57% higher in the augmented group compared to controls (744 ± 219 N vs postcyclic 473 ± 169 N, respectively [P = .015]). There was no difference in mode of failure between the control knees and those augmented with suture tape, with approximately half failing from pull off of the tendon from the bone plug and half with pull out of the bone plug from the tunnel.

CONCLUSION

Independent suture tape augmentation of a BTB ACL reconstruction grafts was associated with a 104% increase in graft stiffness and a 57% increase in load at failure compared to nonaugmented BTB grafts.

CLINICAL RELEVANCE

In vivo suture tape augmentation of a BTB ACL reconstruction increases graft construct strength and stiffness, which may reduce graft failure in the clinical setting.

Current and future of anterior cruciate ligament reconstruction techniques

In recent years, anterior cruciate ligament (ACL) reconstruction has generally yielded favorable outcomes. However, ACL reconstruction has not provided satisfactory results in terms of the rate of returning to sports and prevention of osteoarthritis (OA) progression. In this paper, we outline current techniques for ACL reconstruction such as graft materials, double-bundle or single-bundle reconstruction, femoral tunnel drilling, all-inside technique, graft fixation, preservation of remnant, anterolateral ligament reconstruction, ACL repair, revision surgery, treatment for ACL injury with OA and problems, and discuss expected future trends. To enable many more orthopedic surgeons to achieve excellent ACL reconstruction outcomes with less invasive surgery, further studies aimed at improving surgical techniques are warranted. Further development of biological augmentation and robotic surgery technologies for ACL reconstruction is also required.

Arthroscopic Primary Repair for Partial Proximal Anterior Cruciate Ligament Tear in Military Personnel

OBJECTIVE

To evaluate the short-term clinical outcomes of arthroscopic primary repair for partial proximal anterior cruciate ligament (ACL) tear in a young, active duty military population.

DESIGN

Retrospective cohort study.

SETTING

A national tertiary-level medical and academic institution.

PATIENTS

Nineteen active duty military patients with partial proximal ACL tears and excellent tissue quality were included and 18 were finally analyzed.

INTERVENTIONS

All patients underwent arthroscopic primary repair using a suture anchor technique between March 2014 and June 2016.

MAIN OUTCOME MEASURES

Clinical outcomes were evaluated using anterior drawer test (ADT), Lachman test, pivot shift test, 3-km run test, 10 m × 5 shuttle run test, physical readiness test (PRT) score, Tegner activity score, Lysholm score, modified Cincinnati score, International Knee Documentation Committee (IKDC) subjective score, and magnetic resonance imaging.

RESULTS

At final follow-up, 17 patients had negative ADT, Lachman, and pivot shift examination findings, and 1 patient had a 1+ ADT, negative Lachman, and pivot shift result. Mean 3-km run time at final follow-up was not statistically different from that preinjury (12:55 vs 12:39, P = 0.071), nor were the 10 m × 5 shuttle run time (23.4 vs 22.9, P = 0.235), PRT score (82.5 vs 85.1, P = 0.086), and Tegner activity score (7.8 vs 7.9, P = 0.083). Mean Lysholm score at final follow-up was significantly improved compared with that preoperative (93.1 vs 70.7, P < 0.001), so were the modified Cincinnati score (90.4 vs 58.6, P < 0.001) and IKDC subjective score (88.3 vs 67.4, P < 0.001).

CONCLUSIONS

Arthroscopic primary repair can achieve short-term clinical success in high-demand military patients with partial proximal ACL tears and excellent tissue quality.

Rehabilitation Principles to Consider for Anterior Cruciate Ligament Repair

CONTEXT

Injury to the anterior cruciate ligament (ACL) is among the most common orthopaedic injuries, and reconstruction of a ruptured ACL is a common orthopaedic procedure. In general, surgical intervention is necessary to restore stability to the injured knee, and to prevent meniscal damage. Along with surgery, intense postoperative physical therapy is needed to restore function to the injured extremity. ACL reconstruction (ACLR) has been the standard of care in recent decades, and advances in surgical technology have reintroduced the prospect of augmented primary repair of the native ACL via a variety of methods.

EVIDENCE ACQUISITION

A search of PubMed database of articles and reviews available in English was performed through 2020. The search terms ACLR, anterior cruciate ligament repair, bridge enhanced acl repair, suture anchor repair, dynamic intraligamentary stabilization, internal bracing, suture ligament augmentation, and internal brace ligament augmentation were used.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 5.

RESULTS

No exact consensus exists on effective rehabilitation protocols after ACL repair techniques, as the variation in published protocols seem even greater than the variation in those for ACLR. For some techniques such as internal bracing and dynamic interligamentary stabilization, it is likely permissible for the patients to progress to full weightbearing and discontinue bracing sooner. However, caution should be applied with regard to earlier return to sport than after ACLR as to minimize risk for retear.

CONCLUSION

More research is needed to address how physical therapies must adapt to these innovative repair techniques. Until that is accomplished, we recommend that physical therapists understand the differences among the various ACL surgery techniques discussed here and work with the surgeons to develop a rehabilitation protocol for their mutual patients.

STRENGTH OF RECOMMENDATION TAXONOMY (SORT)

C.

Repair versus reconstruction for proximal anterior cruciate ligament tears: a study protocol for a prospective multicenter randomized controlled trial

Background

For active patients with a tear of the anterior cruciate ligament (ACL) who would like to return to active level of sports, the current surgical gold standard is reconstruction of the ACL. Recently, there has been renewed interest in repairing the ACL in selected patients with a proximally torn ligament. Repair of the ligament has (potential) advantages over reconstruction of the ligament such as decreased surgical morbidity, faster return of range of motion, and potentially decreased awareness of the knee. Studies comparing both treatments in a prospective randomized method are currently lacking.

Methods

This study is a multicenter prospective block randomized controlled trial. A total of 74 patients with acute proximal isolated ACL tears will be assigned in a 1:1 allocation ratio to either (I) ACL repair using cortical button fixation and additional suture augmentation or (II) ACL reconstruction using an all-inside autologous hamstring graft technique. The primary objective is to assess if ACL repair is non-inferior to ACL reconstruction regarding the subjective International Knee Documentation Committee (IKDC) score at two-years postoperatively. The secondary objectives are to assess if ACL repair is non-inferior with regards to (I) other patient-reported outcomes measures (i.e. Knee Injury and Osteoarthritis Outcome Score, Lysholm score, Forgotten Joint Score, patient satisfaction and pain), (II) objective outcome measures (i.e. failure of repair or graft defined as rerupture or symptomatic instability, reoperation, contralateral injury, and stability using the objective IKDC score and Rollimeter/KT-2000), (III) return to sports assessed by Tegner activity score and the ACL-Return to Sports Index at two-year follow-up, and (IV) long-term osteoarthritis at 10-year follow-up.

Discussion

Over the last decade there has been a resurgence of interest in repair of proximally torn ACLs. Several cohort studies have shown encouraging short-term and mid-term results using these techniques, but prospective randomized studies are lacking. Therefore, this randomized controlled trial has been designed to assess whether ACL repair is at least equivalent to the current gold standard of ACL reconstruction in both subjective and objective outcome scores.

Trial registration

Registered at Netherlands Trial Register (NL9072) on 25th of November 2020.

Self-Tensioning Feature of Knotless Suture Anchor Provides Reproducible Knotless Fixation Independent of Initial Tension

Background:

Anterior cruciate ligament (ACL) reconstruction with suture tape reinforcement has been shown to biomechanically reduce elongation and increase ultimate strength. However, the amount and consistency of the achieved tension after primary fixation using knotless suture anchors remains unclear.

Purpose:

To determine whether initial tensioning of suture tape before fixation with a knotless suture anchor significantly affects final tension of the suture tape.

Study Design:

Controlled laboratory study.

Methods:

We secured 15 pairs of Sawbones blocks with predrilled tunnels to a tensile testing machine. Suture tape was inserted through a suspensory fixation button on the representative femoral block and threaded top-down through the base of the tibial block over an attachable button system. The suture tape was attached with a knotless suture anchor in a predrilled and tapped hole on the tibial block under the following pretensioning conditions: (1) slight tension of 5 N, (2) no tension, and (3) initial slack. The suture anchor was inserted as the load-time data were recorded. After initial block testing, a porcine model of 24 tibias was used to test the same pretensioning conditions. The initial loads during anchor insertion and screw-in were measured, as well as final tension.

Results:

During block testing, no difference in final tensioning was found when comparing the slight-tension, no-tension, and slack groups (42.3 ± 5.3, 37.7 ± 6.4, and 40.2 ± 7.0 N, respectively; P = .528). Similar to block testing, no difference in final tensioning was found when comparing the slight-tension, no-tension, and slack groups using the porcine model (43.64 ± 6.69, 48.09 ± 13.93, and 44.52 ± 6.84 N, respectively; P = .633).

Conclusion:

The final tension of the suture tape construct appears to be reproducible and consistent, independent of the initial tension introduced with suture anchor placement within the tested parameters.

Clinical Relevance:

The results of the current study can help optimize the placement technique of independent suture tape reinforcement for ACL reconstruction, which is a promising strategy to help prevent ACL rerupture, particularly in the early phases of postoperative rehabilitation.

An arthroscopic repair technique for proximal anterior cruciate tears in children to restore active function and avoid growth disturbances

PURPOSE

The aim of this study was to assess midterm clinical outcomes in Tanner 1-2 patients with proximal anterior cruciate ligament (ACL) tears following arthroscopic-surgical repair using an absorbable or an all-suture anchor.

METHODS

Fourteen (9.2 ± 2.9 years-old) of 19 skeletally immature patients reached the 2 years of clinical follow-up. Physical examinations included the Lachman test, Pivot-shift test, One-leg Hop test, Pedi-IKDC as well as Lysholm and Tegner activity scores; knee stability was measured with a KT-1000 arthrometer. Overall re-rupture rates were also evaluated in all operated patients.

RESULTS

At 2 years post-surgery, the Lysholm score was 93.6 ± 4.3 points, and the Pedi-IKDC score was 95.7 ± 0.1. All patients returned to the same sport activity level as prior to ACL lesion within 8.5 ± 2.9 months, with one exception who reported a one-point reduction in their Tegner Activity score. No leg-length discrepancies or malalignments were observed. Four patients presented grade 1 Lachman scores, and of these, three presented grade 1 (glide) score at Pivot-shift; clinical stability tests were negative for all other patients. Anterior tibial shift showed a mean side-to-side difference of 2.2 mm (range 1-3 mm). The One-leg Hop test showed lower limb symmetry (99.9% ± 9.5) with the contralateral side. Overall, 4 out of 19 patients presented a re-rupture of the ACL with a median time between surgery and re-rupture of 3.9 years (range 1-7).

CONCLUSION

This surgical technique efficiently repairs proximal ACL tears, leading to a restoration of knee stability and a quick return to an active lifestyle, avoiding growth plate disruption.

LEVEL OF EVIDENCE

IV.

Anterior cruciate ligament tear patterns in young patients: An arthroscopic multicenter study

INTRODUCTION

In the last decade, there has been a renewed interest in anterior cruciate ligament (ACL) preservation surgeries in the younger patients. Several ACL preservation techniques such as primary repair, augmented repair, and scaffold repair have been described based on the particular tear type and pattern. The purpose of this study was to determine the distribution of tear patterns in young patients presenting with an acute ACL injury.

METHODS

A prospective observational study was performed at two tertiary children's hospitals. Patients under 18 years undergoing ACL reconstruction within 8 weeks of initial injury were included from 2017 to 2019. Tear patterns were classified by two orthopedic surgeons from each of the two centers during arthroscopic ACL reconstruction into 4 types: I. Avulsion off the femur, II. <10% of total ACL length tear from femoral end, III. Mid-substance tear and IV. Single bundle tear. For reliability, the four surgeons classified ACL injury (2 rounds each) based on de-identified intraoperative videos of 33 randomly selected surgical ACL cases. Inter and intra-rater reliability studies were calculated using Kappa statistics.

RESULTS

224 patients (123 males, 101 females) with mean age of 16 (range: 9-18) years were enrolled in this study. Fifty-seven (25%) patients reported contact injury while 167 (75%) reported non-contact. Isolated ACL injury was recorded in 70 (31%) patients, while concomitant injuries were recorded in 154 patients (69%). The most common associated injury was lateral meniscus tear (35%), followed by lateral and medial meniscus tears (20%). According to our classification, 31 (14%) patients were Type I, 30 (13%) were Type II, 139 (62%) were Type III, 18 (8%) were Type IV. The intra-rater reliability was excellent for 2 reviewers, good for 1 and marginal for another. The overall inter-rater reliability for all 4 reviewers was marginal for both readings. There was no statistical difference in the occurrence of type of tear based on the mechanism of injury (contact vs non-contact) or age of the patients.

CONCLUSIONS

This is the first multicenter study using an arthroscopic assessment to classify the location of ACL tear in the young population. It gives us further insight on the possible application for surgeries to preserve the ACL in this group. Larger studies incorporating these findings with MRI evaluation and ACL repair techniques are needed to confirm the utility of this information to decide the eligibility for repair in pediatric patients.

Biological Augmentation of ACL Repair and Reconstruction: Current Status and Future Perspective

Historically, anterior cruciate ligament (ACL) suture repair mostly resulted in failure because of intra-articular hypovascularity and poor intrinsic healing capacity of ACL. ACL reconstruction was therefore deemed the gold standard with a high success rate because of more evolved surgical technique. There are, however, clinical and subclinical disadvantages of reconstruction; low rate in full recovery to sports, donor harvest morbidity, tunnel enlargement, and incomplete microscopic healing of the graft. Recent experimental and clinical studies on biological augmentation of mesenchymal stem cells, platelet-rich plasma, or the other biologic agents with scaffold suggested potential feasibility of positive effects by such bio-therapies for both ACL repair and reconstruction. Biological augmentation of ACL surgery is still in the exploratory stages and more evidence from preclinical and clinical studies is required for implementation in clinical practice.

Independent Suture Tape Internal Brace Reinforcement of Bone-Patellar Tendon-Bone Allografts: Biomechanical Assessment in a Full-ACL Reconstruction Laboratory Model

Internal bracing for anterior cruciate ligament (ACL) surgery is a relatively new concept. The purpose of this study was to evaluate the effects of an "independent" button-fixed internal brace on the biomechanical properties of ACL reconstruction in a full-construct experimental model. Three groups (n = 10 each) were tested in a full-construct porcine-bone model with human bone-patellar tendon-bone allografts using different reconstruction techniques: interference screw fixation on femur and tibia (S-S group), adjustable-loop device (ALD) fixation on the femur with tibial interference screw without suture tape (ALD-S group), and with internal brace (ALD-S-IB group). Measured outcomes included cyclic displacement, stiffness, and ultimate load to failure. The ALD-S-IB group (2.9 ± 0.8 mm) displaced significantly less than the ALD-S (4.2 ± 0.9 mm; p = 0.015) and S-S group (4.3 ± 1.1 mm; p = 0.017). No significant difference was found between the ALD-S and the S-S group. Construct stiffness was significantly higher for the ALD-S-IB group (156 ± 23 N/mm) and the ALD-S group (122 ± 28 N/mm) than for the S-S group (104 ± 40 N/mm; p = 0.003 and p = 0.0042), but there was no significant difference between both ALD groups. Similarly, ultimate loads in the ALD-S-IB (758 ± 128 N) and the ALD-S groups (628 ± 223 N) were significantly greater than in the S-S group (416 ± 167 N; p < 0.001 and p = 0.025), but there was no significant difference between ALD groups. Adding an internal brace reinforcement to an ALD in a full-construct experimental model significantly decreased cyclic displacement by 31% without increasing construct stiffness or ultimate load significantly. These results indicate that suture tape internal bracing of bone-patellar tendon-bone allograft ACL reconstruction decreases cyclic displacement during experimental testing, which has clinical implications regarding initial construct stability.

Paediatric proximal ACL tears managed with direct ACL repair is safe, effective and has excellent short-term outcomes

PURPOSE

Anterior cruciate ligament (ACL) surgery in the paediatric population has long been a challenge. Non-operative treatment will result in persistent instability which can lead to chondral and meniscal injuries. The results of primary open ACL repair are poor. Concerns of growth plate disturbance with transphyseal techniques and issues with relatively small-diameter grafts in Tanner 1 and 2 patients, which are inadequate, have contributed to these challenges. With advancing instrumentation, there is renewed interest in ACL repair. The minimally invasive approach of arthroscopic primary ACL repair retains the native ligament. The objective and subjective outcomes at 2 years are presented.

METHODS

Paediatric patients, less than 16 years of age, presenting acutely with complete proximal ACL ruptures underwent direct arthroscopic ACL repair, reinforced by a temporary internal brace, which was subsequently removed after 3 months. Patient-reported outcome measures including the Lysholm, Tegner and KOOS scores were collected at 6 months, 1 year and 2 years post-operatively.

RESULTS

Twenty patients (age 6-16) completed data at 2 years post-operatively. There were no failures, no complications and no growth disturbance out to 2 years. The 2-year postoperative outcomes; Lysholm 95 (90-100), Tegner 7 (6-10), KOOS-Child 96.5 (88.9-100) demonstrated statistically significant improvements following surgery (p < 0.001). Objective measurements with an accelerometer did not demonstrate any significant side-to-side difference.

CONCLUSION

ACL repair for proximal ACL tears in the paediatric population demonstrates the potential for excellent outcomes at short-term follow-up. This presents an attractive alternative to ACL reconstruction when an adequate ACL remnant permits direct repair. Our results demonstrate that paediatric ACL repair is safe and effective.

Treatment of Acute Proximal Anterior Cruciate Ligament Tears-Part 1: Gap Formation and Stabilization Potential of Repair Techniques

Background:

Recently, there has been a resurgence of interest in primary repair of the anterior cruciate ligament (ACL), with fixation techniques evolving. However, to date, there have been no biomechanical studies comparing fixed to adjustable fixation repair techniques.

Hypothesis:

Adjustable ACL repair provides for improved stabilization compared with fixed techniques with respect to both gap formation and residual load-bearing capability.

Study Design:

Controlled laboratory study.

Methods:

A total of 4 different ACL repair techniques (n = 5 per group), including single– and double–cinch loop (CL) cortical button fixation as well as knotless single–suture anchor fixation, were tested using a porcine model. For adjustable single-CL loop fixation, additional preconditioning (10 cycles at 0.5 Hz) was performed. The force after fixation and the actuator displacement to achieve a time-zero preload of 10 N were measured for fixed techniques. Incrementally increasing cycling (1 mm/500 cycles) from 1 to 8 mm was performed for 4000 cycles at 0.75 Hz before pull to failure (50 mm/min). The final residual peak load and gap formation for each test block were analyzed as well as ultimate strength.

Results:

Knot tying of a single-CL over a button (mean ± SD, 0.66 ± 0.23 mm) and knotless anchor fixation (0.20 ± 0.12 mm) resulted in significant time-zero gaps (P < .001) and significantly higher overall gap formation at reduced residual loading (analysis of covariance, P < .001) compared with both the double-CL loop and adjustable fixation techniques. The adjustable group showed the highest failure load and stiffness, at 305.7 N and 117.1 N/mm, respectively. The failure load of the knotted single-CL group was significantly reduced compared with all other groups (P < .001).

Conclusion:

Adjustable single-CL cortical button fixation with intraoperative preconditioning optimized time-zero ACL tension and led to significantly improved stabilization and reduced gap formation, with the highest ultimate strength. Single-CL loop knot tying over the button and knotless anchor fixation resulted in time-zero gaps to achieve slight tension on the ACL and significantly higher gap formation at reduced load-bearing capability.

Clinical Relevance:

Although the clinical relevance of gap formation is uncertain, a biomechanical understanding of the stabilization potential of current ACL repair techniques is pertinent to the continued evolution of surgical approaches to enable better clinical outcomes.

Arthroscopic primary repair of proximal anterior cruciate ligament tears seems safe but higher level of evidence is needed: a systematic review and meta-analysis of recent literature

PURPOSE

To assess the outcomes of the various techniques of primary repair of proximal anterior cruciate ligament (ACL) tears in the recent literature using a systematic review with meta-analysis.

METHODS

PRISMA guidelines were followed. All studies reporting outcomes of arthroscopic primary repair of proximal ACL tears using primary repair, repair with static (suture) augmentation and dynamic augmentation between January 2014 and July 2019 in PubMed, Embase and Cochrane were identified and included. Primary outcomes were failure rates and reoperation rates, and secondary outcomes were patient-reported outcome scores.

RESULTS

A total of 13 studies and 1,101 patients (mean age 31 years, mean follow-up 2.1 years, 60% male) were included. Nearly all studies were retrospective studies without a control group and only one randomized study was identified. Grade of recommendation for primary repair was weak. There were 9 out of 74 failures following primary repair (10%), 6 out of 69 following repair with static augmentation (7%) and 106 out of 958 following dynamic augmentation (11%). Repair with dynamic augmentation had more reoperations (99; 10%), and more hardware removal (255; 29%) compared to the other procedures. All functional outcome scores were > 85% of maximum scores.

CONCLUSIONS

This systematic review with meta-analysis found that the different techniques of primary repair are safe with failure rates of 7-11%, no complications and functional outcome scores of > 85% of maximum scores. There was a high risk of bias and follow-up was short with 2.1 years. Prospective studies comparing the outcomes to ACL reconstruction with sufficient follow-up are needed prior to widespread implementation.

LEVEL OF EVIDENCE

IV.

Treatment of Acute Proximal Anterior Cruciate Ligament Tears-Part 2: The Role of Internal Bracing on Gap Formation and Stabilization of Repair Techniques

BACKGROUND

The latest biomechanical studies on some form of internal bracing have shown improved stabilization for anterior cruciate ligament (ACL) repair, but gap formation and load-sharing function have not yet been reported.

HYPOTHESIS

Internal bracing of an adjustable ACL repair construct provides improved stabilization with reduced gap formation and higher residual loading on the ACL.

STUDY DESIGN

Controlled laboratory study.

METHODS

Internally braced ACL repair constructs with single- and double-cinch loop (CL) cortical buttons, a knotless suture anchor, and a single-CL cortical button with adjustable loop fixation (CLS-ALD) were tested (n = 20 each) in a porcine model at 4 different loads (n = 5 each) over 4000 cycles at 0.75 Hz (n = 80 total). The CLS-ALD technique allowed for additional preconditioning (10 cycles at 0.5 Hz). Test results of the isolated internal brace groups served as a baseline for comparison. Lastly, specimens were pulled to failure (50 mm/min) with a cut internal brace. Final loading and gap formation on the ACL repair construct as well as ultimate strength were analyzed.

RESULTS

A statistical significance for peak loads over peak elongation was found between the CLS-ALD and all other reinforced groups (analysis of covariance, P < .001). Accordingly, the adjustable repair technique showed improved load-bearing capability with the internal brace compared with all other fixed repair groups and revealed significantly higher loads than the knotted single-CL group. Also, significantly reduced gap formation was found for the CLS-ALD compared with all other groups (P < .001), with no gap formation up to 150 N with a final gap of 0.85 ± 0.31 mm at 350 N. A significantly higher ultimate failure load (866.2 ± 104.0 N; P < .001) was found for the button-fixed internal brace group compared with all other groups.

CONCLUSION

Internal bracing had a crucial role in improving the stabilization potential of ACL repair at loads occurring during normal daily activity. The added strength of the internal brace allowed for reducing peak loads on the ACL repair construct as well as restricting gap formation to below 3 mm at loads up to 350 N.

CLINICAL RELEVANCE

Improvements in the mechanical characteristics of current ACL repair techniques that enable reduced gap formation and allow for early range of motion and accelerated rehabilitation may strengthen the self-healing response with the formation of stable scar tissue.

Anterior Cruciate Ligament Reconstruction With Suture Tape Augmentation: A Surgical Technique

The anterior cruciate ligament (ACL) is the most common ligamentous knee injury and often is encountered in those participating in multidirectional sports. ACL reconstruction is the most commonly performed knee ligament reconstruction and employs a variety of surgical techniques but still is challenged by residual laxity and graft rupture. To help address and prevent future ACL failures, new repair and reconstruction techniques have been employed that incorporate suture augmentation (InternalBrace; Arthrex, Naples, FL), which protects the graft during healing and ligamentization. Our goal of this article is to provide a surgical technique of suture augmentation with ACL reconstruction.

Study protocol: a single-blind, multi-center, randomized controlled trial comparing dynamic intraligamentary stabilization, internal brace ligament augmentation and reconstruction in individuals with an acute anterior cruciate ligament rupture: LIBRƎ study

Background

The current gold standard for the treatment of an anterior cruciate ligament (ACL) rupture is reconstruction with tendon graft. Recently, two surgical ACL repair techniques have been developed for treating an acute ACL rupture: Dynamic Intraligamentary Stabilization (DIS, Ligamys®) and Internal Brace Ligament Augmentation (IBLA, InternalBrace™). We will conduct a single-blind, multi-center, randomized controlled trial which compares DIS, IBLA and reconstruction for relative clinical efficacy and economic benefit.

Methods

Subjects, aged 18–50 years, with a proximal, primary and repairable ACL rupture will be included. DIS is preferably performed within 4 weeks post-rupture, IBLA within 12 weeks and reconstruction after 4 weeks post-rupture. Patients are included in study 1 if they present within 0–4 weeks post-rupture and surgery is feasible within 4 weeks post-rupture. Patients of study 1 will be randomized to either DIS or IBLA. Patients are included in study 2 if they present after 4 weeks post-rupture and surgery is feasible between 5 and 12 weeks post-rupture. Patients of study 2 will be randomized to either IBLA or reconstruction. A total of 96 patients will be included, with 48 patients per study and 24 patients per study arm. Patients will be followed-up for 2 years. The primary outcome is change from baseline (pre-rupture) in International Knee Documentation Committee score to 6 months post-operatively. The main secondary outcomes are the EQ-5D-5 L, Tegner score, Lysholm score, Lachman test, isokinetic and proprioceptive measurements, magnetic resonance imaging outcome, return to work and sports, and re-rupture/failure rates. The statistical analysis will be based on the intention-to-treat principle. The economic impact of the surgery techniques will be evaluated by the cost-utility analysis. The LIBRƎ study is to be conducted between 2018 and 2022.

Discussion

This LIBRƎ study protocol is the first study to compare DIS, IBLA and ACL reconstruction for relative clinical efficacy and economic benefit. The outcomes of this study will provide data which could aid orthopaedic surgeons to choose between the different treatment options for the surgical treatment of an acute ACL rupture.

Trial registration

This study is registered at ClinicalTrials.gov; NCT03441295. Date registered 13.02.2018.

The Locations of Anterior Cruciate Ligament Tears in Pediatric and Adolescent Patients: A Magnetic Resonance Study

BACKGROUND

Recently, a resurgence of interest has been noted in anterior cruciate ligament (ACL) preservation in pediatric and adolescent patients. Different tear types, defined by their tear location, require different preservation techniques: proximal and distal avulsion tears can be treated with arthroscopic primary repair, whereas primary repair with biological scaffold has been proposed for midsubstance tears. The goal of this study was to assess the distribution of different tear types in pediatric and adolescent patients, as these are currently unknown.

METHODS

A retrospective search in an institutional radiographic database was performed for patients under 18.0 years undergoing knee magnetic resonance imaging (MRI) for ACL tears between June 2005 and June 2016. Patients with reports of chronic tears, partial tears, and multiligamentous injuries were excluded.Tear locations were graded using MRI as: proximal avulsion (distal remnant length >90% of total length; type I), proximal (75% to 90%; type II), midsubstance (25% to 75%; type III), distal (10% to 25%; type IV), and distal avulsion (<10%; type V).

RESULTS

A total of 274 patients (59% girls; mean±SD age, 15.1±2.1 y; range, 6.9 to 18.0 y) were included. Frequency of type I tears was 15%, type II 23%, type III 52%, type IV 1%, and type V 8% (of which 7% had bony avulsion).Prevalence of tear types varied with age. At age 6 to 10 years, 93% were type V (bony) avulsion tears. At age 11 to 13 years, 32% were type I, 16% type II, 32% type III, and 16% type V. At age 14 to 17 years, type III tears were more common (57%) than type I (14%), type II (25%) and type V (2%) tears.

CONCLUSIONS

It was noted that the ACL was torn at different locations depending on the patients' age. These data provide more information on the potential application for ACL preservation in pediatric and adolescent patients. Future studies correlating these findings with arthroscopy are needed before using MRI for preoperative planning of ACL preservation surgery.

LEVEL OF EVIDENCE

Diagnostic level III.

Anterior Cruciate Ligament Repair Outcomes: An Updated Systematic Review of Recent Literature

PURPOSE

To critically review recent literature on outcomes following primary surgical repair of the anterior cruciate ligament (ACL).

METHODS

In December 2018, a search of the MEDLINE database was conducted for English language articles reporting clinical outcomes of ACL repair from 2003 to 2018. Included studies were evaluated for patient demographics, patient-reported outcome measures, return to sports/work, patient satisfaction, and postoperative complications. Subgroup analysis was conducted for studies that included patients with only type 1/proximal ACL ruptures.

RESULTS

Twenty-eight studies satisfied the inclusion criteria, comprising 2,401 patients (52.3% male, 35.7% female, 12.0% unspecified gender) with mean age ranging from 6.0 to 43.3 years. Most studies were conducted in Europe (82.1%), were level of evidence IV (60.7%), and were designed as case series (57.1%). Fourteen investigations (50.0%) used primary suture repair and 14 (50.0%) used dynamic intraligamentary stabilization. Preoperative ranges for Lysholm, International Knee Documentation Committee Score subjective, and Tegner scores were 28 to 100, 94.1 to 100, and 2 to 9, respectively. Postoperative ranges for the same measures were 80 to 100, 54.3 to 98, and 3.67 to 7, respectively. Time to return to sport/work ranged from 3.1 ± 3.3 to 17.4 ± 1.5 weeks. Frequency of rerupture, revision ACL surgery, and overall reoperations were as high as 23.1%, 33.3%, and 51.5%, respectively. Overall ACL repair survivorship ranged from 60.0% to 100.0%. In subgroup analysis for proximal ruptures treated with repair, the rates of revision ACL reconstruction (ACLR) and total reoperations were as high as 12.9% and 18.2%, respectively.

CONCLUSIONS

Based on our cumulative findings across 2,401 patients from the 28 included studies, it appears that ACLR results in better survivorship and patient-perceived postoperative improvement when compared with ACL repair. At present, ACLR appears to remain the superior treatment strategy in the vast majority of cases.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II to IV studies.

Outcome Measures After ACL Injury in Pediatric Patients: A Scoping Review

BACKGROUND

The incidence of anterior cruciate ligament (ACL) injuries in children is increasing. However, no standardized core set of outcome measures exists for evaluating pediatric ACL injuries.

PURPOSE

To perform a scoping review of the literature to identify patient-reported outcome measures (PROMs) and objective outcome measures used to evaluate pediatric patients after ACL injury and to classify these in accordance with the International Classification of Functioning, Disability, and Health (ICF) domains.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

The literature was systematically searched with the PubMed, EMBASE, CINAHL, and PEDro databases. The inclusion criteria were Danish, Norwegian, Swedish, German, or English language; publication between 2010 and 2018; pediatric ACL injury (patients ≤15 years old); and outcome measures. The selected papers were screened for title, abstract, and full text in accordance with predefined inclusion and exclusion criteria.

RESULTS

A total of 68 papers (4286 patients; mean ± SD age, 12.2 ± 2.3 years) were included. Nineteen PROMs and 11 objective outcome measures were identified. The most frequently reported PROMs were the International Knee Documentation Committee (IKDC) Subjective Knee Form (51% of studies), Lysholm scoring scale (46% of studies) and Tegner activity rating scale (37% of studies). Additionally, return to sport was reported in 41% of studies. The most frequent objective measures were knee laxity (76% of studies), growth disturbances (69% of studies), range of motion (41% of studies), and muscle strength (21% of studies). With respect to the ICF domains, the IKDC covered all 3 ICF health domains, the Lysholm score covered the Body Structure and Function and the Activity Limitation domains, while the Tegner score covered the Participation Restriction domain. Objectively measured knee joint laxity, range of motion, and muscle strength covered 1 domain (Body Structure and Function).

CONCLUSION

Pediatric patients with ACL injury were mainly evaluated subjectively with the IKDC and objectively by knee joint laxity. No consensus exists in the evaluation of children after ACL injury. The majority of applied outcome measures are developed for adults. To cover the ICF health domains, future research needs to consider reliable and valid outcome measures relevant for pediatric patients with ACL injury.

Suture Augmented Versus Standard Anterior Cruciate Ligament Reconstruction: A Matched Comparative Analysis

PURPOSE

To compare outcomes between standard anterior cruciate ligament reconstruction (ACLR) using hamstring grafts with and without suture augmentation (SA).

METHODS

Patients who underwent ACLR with hamstring autografts or allografts with minimum 2-year follow-up were retrospectively reviewed. Patients undergoing ACLR with SA were matched 1:1 by age, gender, body mass index, graft type, and revision status to standard ACLR. Range of motion, pain, postoperative activity, patient-reported outcome measures (PROMs), and complications were collected. Paired 2-tailed Student's t-tests and Pearson's χ²-tests were used for continuous and categorical variables, respectively. A multivariate analysis of variance was conducted. Return to preinjury activity level was assessed using Spearman's rho and Pearson's χ²-tests.

RESULTS

Sixty patients at a mean age of 29.50 ± 6.60 years, 43.4% male, body mass index 26.27 ± 3.37, and follow-up of 29.54 ± 5.37 months were included. Preoperative PROMs were not significantly different (P >. 05). Postoperative range of motion was similar between groups (P = .457). Postoperative average daily (0.60 ± 1.25 vs 1.66 ± 1.90) and maximum daily pain (1.57 ± 1.83 vs 3.35 ± 2.28) were significantly lower for SA (P < .014). SA predicted improvement in PROMs (P < .05) and maximum pain scores (P = .001). SA was significantly correlated with improved time to return to preinjury activity level (9.17 ± 2.06 vs 12.88 ± 3.94 months; P = .002) and percentage of preinjury activity level (93.33% ± 13.22% vs 83.17% ± 17.69%; P = .010). There was a trend toward improved rate of return to preinjury activity level for SA (76.7% vs 56.7%; P = .100).

CONCLUSIONS

Our study demonstrates that SA hamstring ACLRs were associated with improved PROMs, less pain, and a higher percentage of and earlier return to preinjury activity level when compared with standard hamstring ACLRs without evidence of overconstraint.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Identifying candidates for arthroscopic primary repair of the anterior cruciate ligament: A case-control study

INTRODUCTION

There has been a recent resurgence of interest in arthroscopic primary repair of proximal anterior cruciate ligament (ACL) tears. Patient selection is critical but not much is currently known on what predicts the possibility of repair. Goal of this study was therefore to assess predictive factors for the possibility of arthroscopic primary ACL repair.

METHODS

In this retrospective case-control study, all patients undergoing ACL surgery in a ten-year interval were included. Patients were treated with primary repair if there was a proximal tear and good tissue quality, or otherwise underwent ACL reconstruction. Collected data were age, gender, BMI, injury-to-surgery delay, injury mechanism and concomitant injuries. Receiver operating characteristic curves were used to find cutoff values, and all significant dependent variables were used in multivariate logistic analysis to assess independent predictors for the possibility of primary repair.

RESULTS

Three hundred sixty-one patients were included, of which in 158 patients (44%) primary repair was possible. Multivariate analysis (R² = 0.340, p < 0.001) showed that age > 35 years (Odds ratio [OR] 4.2, 95% CI 2.4-7.5,p < 0.001), surgery within 28 days (OR 3.3, 95% CI 1.9-5.7, p < 0.001), and BMI <26 (OR 1.9, 95% CI 1.1-3.3,p = 0.029) were predictive for the possibility of primary repair, and lateral meniscus injury presence decreased the likelihood of repair (OR 0.5, 95% CI 0.3-0.8, p = 0.008).

CONCLUSION

In this large cohort study, it was noted that 44% of patients had repairable ACL tears. Primary repair was more likely to be possible in older patients, patients with lower BMI and when surgery was performed within four weeks of injury.

Sternoclavicular Joint Reconstruction Fracture Risk Is Reduced With Straight Drill Tunnels and Optimized With Tendon Graft Suture Augmentation

Background:

Despite the rare entity of sternoclavicular joint (SCJ) instability, a variety of different reconstruction techniques for SCJ dislocations have been described. A technique with oblique drilling has been proposed to reduce intraoperative risks.

Purpose:

To biomechanically investigate different cerclage reconstruction techniques and the benefit of additional reinforcement using suture tape.

Study Design:

Controlled laboratory study.

Methods:

Reconstructed artificial bone specimens were mounted on a mechanical testing machine. They were subjected to anterior and posterior translation, analyzing ultimate strength, displacement, stiffness, and elongation. For stage 1, different angulations of the drill tunnels through the sternum and clavicle were compared. Straight drill tunnels from anterior to posterior were compared with 45° oblique drill tunnels. For stage 2, three different materials for cerclage reconstruction were compared: (1) suture tape alone (FT group), (2) tendon graft alone (tendon group), and (3) tendon graft with suture tape augmentation (tendon+FT group).

Results:

For the FT group, in the anterior and posterior directions, straight drill holes resulted in a significantly higher load to failure (936.9 ± 122.5 N) compared with oblique ones (434.5 ± 20.2 N) (P < .0001). During cyclic testing, all specimens with straight drill holes survived the 5- to 550-N step, while all specimens with oblique ones failed during the 5- to 450-N step. Analyzing the graft material choice, the mean load to failure was 556.6 ± 174.3 N for the tendon group, 936.9 ± 122.5 N for the FT group, and 767.0 ± 110.7 N for the tendon+FT group (P = .089). The stiffness of the tendon+FT group was significantly lower than that of the FT group and significantly higher than that of the tendon group.

Conclusion:

Oblique tunnel placement during SCJ reconstruction, while reducing the intraoperative risk, results in decreased primary stability of the construct. Tendon graft reconstruction with suture tape augmentation leads to enhanced stability and optimizes biomechanical properties of the construct.

Clinical Relevance:

The surgical technique with straight drill holes has superior initial biomechanical properties and may likewise produce superior clinical outcomes in the treatment of SCJ instability. Suture tape augmentation can provide additional stability to reconstruction procedures.

Postoperative Magnetic Resonance Imaging following Arthroscopic Primary Anterior Cruciate Ligament Repair

Introduction

Recently, there has been a resurgence of interest in arthroscopic primary anterior cruciate ligament (ACL) repair. To date, no studies have assessed the role of postoperative magnetic resonance imaging (MRI) on the status and maturation of the repaired ligament. The goal of this study was therefore to assess (I) the accuracy of MRI on rerupture of the repaired ligament and (II) the maturation of the repaired ACL.

Methods

All postoperative MRIs of patients that underwent arthroscopic primary ACL repair were included. A musculoskeletal radiologist, blinded for MRI indication, surgery-MRI time interval, and clinical stability, retrospectively assessed the ligament continuity and graded ligament maturation as hypointense (similar to intact PCL), isointense (>50% similar to PCL), or hyperintense (<50% similar to PCL).

Results

Thirty-seven MRIs were included from 36 patients. Mean age was 30 years (range: 14–57 years), and mean surgery-MRI interval was 1.5 years (range: 0.1–4.9 years). The radiologist recognized 6 out of 8 reruptures and 26 out of 29 intact ligaments (sensitivity 75%, specificity 90%, and accuracy 86%). Ligaments in the first year were more often hyperintense than after one year (60% vs. 11%, p=0.02), most often isointense (60%) between one and two years, and more often hypointense after two years than before two years (56% vs. 10%, p=0.03).

Conclusion

Postoperative MRI was found to accurately predict the rerupture of the primarily repaired ACL. Furthermore, it can be expected that the repaired ligament is hyperintense within the first year, while the signal becomes similar to the intact PCL after two years.

ACL Repair With Suture Ligament Augmentation Is Associated With a High Failure Rate Among Adolescent Patients

BACKGROUND

The anterior cruciate ligament (ACL) repair technique avoids graft harvest and therefore the risk of donor site morbidity. However, early failure rates after ACL repair with suture ligament augmentation (SLA) remain high.

PURPOSE

To compare surgical failure, functional outcomes, return to sport, and joint laxity between adolescents who underwent ACL repair with SLA and those who underwent ACL reconstruction with quadriceps tendon-patellar bone autograft (QPA).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Adolescent patients (7-18 years old) underwent ACL repair with SLA or ACL reconstruction with QPA. The authors collected data from those who had postoperative information pertaining to repaired ligament or graft failure, range of motion, complications, and return to sport at a minimum of 6 months after surgery. Participants were contacted after surgery to complete study questionnaires.

RESULTS

The cohort included 22 consecutive patients in the SLA group and 157 in the QPA group. The median duration of follow-up was 2.7 years (interquartile range, 2.0-3.6 years) in the QPA group and 3.2 years (2.2-3.4 years) in the SLA group. After adjustment for sex, age, body mass index, and time from injury to surgery, the hazard of graft failure in the SLA group was 10.66 times (95% CI, 3.41-32.92; P < .0001) that of the QPA group. The cumulative incidence of graft failure in the first 3 years after surgery was 48.8% (95% CI, 28.9%-73.1%) in the SLA group, as opposed to 4.7% (2.1%-10.3%) in the QPA group. There was no difference in return to sport between the groups. Among individuals who did not rerupture their ACL, International Knee Documentation Committee and Lysholm scores were comparable between the groups, as well as range of motion.

CONCLUSION

The risk of failure was significantly increased in the SLA group relative to the QPA group. The high risk of failure for the SLA group in this short-term follow-up should be considered when selecting the treatment for adolescent patients with an ACL injury.

Repair and Augmentation with Internal Brace in the Multiligament Injured Knee

The internal brace is a ligament repair bridging concept using braided ultra-high-molecular-weight polyethylene suture tape and knotless bone anchors to reinforce ligament strength to allow early mobilization during early-phase healing. This concept can be used in the management of anterior cruciate ligament, posterior cruciate ligament, anterolateral ligament, medial collateral ligament, posteromedial corner, and posterolateral corner injuries. Ligament reinforcement is a concept in which a graft is reinforced and can be used in all aspects of knee ligament reconstruction. There has been a recent resurgence in ligament repair and recent evidence suggests equivalent outcome results.

Arthroscopic primary repair of proximal anterior cruciate ligament tears: outcomes of the first 56 consecutive patients and the role of additional internal bracing

PURPOSE

Recent outcomes of arthroscopic primary repair of proximal anterior cruciate ligament (ACL) tears have been promising in small cohort studies. The purpose of this study was to assess outcomes of arthroscopic ACL repair in a larger cohort and to assess the role of additional augmentation.

METHODS

The first 56 consecutive patients that underwent arthroscopic ACL repair were examined at minimum 2-year follow-up. The latter 27 patients [48.2% (27/56)] received additional internal bracing with ACL repair. All 56 patients were included (100% follow-up). Mean age at surgery was 33.5 ± 11.3 years (59% male) and mean follow-up 3.2 ± 1.7 years. Clinical examination was performed using the objective International Knee Documentation Committee (IKDC) form. Subjective outcomes were obtained using the Lysholm, modified Cincinnati, Single Assessment Numeric Evaluation (SANE), and subjective IKDC scores.

RESULTS

Six repairs (10.7%) failed and four additional patients underwent reoperation (7.1%): two for meniscus tears and two for suture anchor irritation. Objective IKDC scores were A in 38 (73%), B in 8 (15%) and C/D in 6 (12%) patients. Mean Lysholm score was 94 ± 7.6, modified Cincinnati 94 ± 8.9, SANE 90 ± 12.5, pre-injury Tegner 6.7 ± 1.5, current Tegner 6.2 ± 1.5, and subjective IKDC 90 ± 10.9. Failures rates were 7.4% with and 13.8% without internal bracing (P = 0.672). There were no statistically significant or clinically relevant differences in subjective outcomes.

CONCLUSION

Arthroscopic primary repair has resulted in good objective and subjective outcomes at 3.2-year follow-up in a carefully selected population. The role of additional internal bracing is possibly beneficial, but larger groups are needed to assess this.

LEVEL OF EVIDENCE

III.

A Narrative Review of Four Different New Techniques in Primary Anterior Cruciate Ligament Repair: "Back to the Future" or Another Trend?

Recently, four different operative techniques, referring to the primary anterior cruciate ligament (ACL) repair, were described. These are the dynamic intraligamentary stabilization (DIS) with Ligamys™, the Bridge-enhanced repair (BEAR), the use of internal brace, and the refixation with suture anchors. The purpose of this study was to assess the already-published, clinical, and pre-clinical results of those techniques. A literature review was conducted and implemented by three independent researchers. Inclusion criteria were clinical or cadaveric or animal studies about patients suffering from ACL rupture, who were treated with one of those four different arthroscopic techniques of primary ACL repair. There were 10 clinical trials dealing with the different techniques of primary ACL repair and 12 cadaveric or animal studies. The majority of the published clinical trials investigated the dynamic intraligamentary stabilization (DIS), while only four studies referred to the three other surgical techniques. Most of the clinical trials suggested that primary ACL repair should be done during the first 14–21 days after a proximal ACL rupture and not later. Further clinical evidence is needed for the techniques of bridge-enhanced ACL repair, internal brace, and suture anchors ACL refixation in order to support the animal and cadaveric biomechanical studies. Till now, the existing clinical trials were not enough to establish the use of those techniques in the ACL-ruptured patients. On the contrary, the Dynamic intraligamentary stabilization with Ligamys™ device demonstrated very promising results in different types of clinical studies.

Is There a Role for Internal Bracing and Repair of the Anterior Cruciate Ligament? A Systematic Literature Review

BACKGROUND

Renewed interest has arisen in arthroscopic anterior cruciate ligament (ACL) repair techniques.

HYPOTHESIS

ACL repair with or without some form of internal bracing could lead to good outcomes in a carefully selected subset of patients.

STUDY DESIGN

Systematic review.

METHODS

An electronic database search was performed to identify 89 papers describing preclinical and clinical studies on the outcome of ACL repair.

RESULTS

Proximal ACL tear patterns showed a better healing potential with primary repair than distal or midsubstance tears. Some form of internal bracing increased the success rate of ACL repair. Improvement in the biological characteristics of the repair was obtained by bone marrow access by drilling tunnels or microfracture. Augmentation with platelet-rich plasma was beneficial only in combination with a structural scaffold. Skeletally immature patients had the best outcomes. Acute repair offered improved outcomes with regard to load, stiffness, laxity, and rerupture.

CONCLUSION

ACL repair may be a viable option in young patients with acute, proximal ACL tears. The use of internal bracing, biological augmentation, and scaffold tissue may increase the success rate of repair.

Anterior cruciate ligament repair - past, present and future

Background

This article provides a detailed narrative review on the history and current concepts surrounding ligamentous repair techniques in athletic patients. In particular, we will focus on the anterior cruciate ligament (ACL) as a case study in ligament injury and ligamentous repair techniques. PubMed (MEDLINE), EMBASE and Cochrane Library databases for papers relating to primary anterior cruciate ligament reconstruction were searched by all participating authors. All relevant historical papers were included for analysis. Additional searches of the same databases were made for papers relating to biological enhancement of ligament healing.

Current standard

The poor capacity of the ACL to heal is one of the main reasons why the current gold standard surgical treatment for an ACL injury in an athletic patient is ACL reconstruction with autograft from either the hamstrings or patella tendon. It is hypothesised that by preserving and repairing native tissues and negating the need for autograft that primary ACL repair may represent a key step change in the treatment of ACL injuries.

History of primary ACL repair

The history of primary ACL repair will be discussed and the circumstances that led to the near-abandonment of primary ACL repair techniques will be reviewed.

New primary repair techniques

There has been a recent resurgence in interest with regards to primary ACL repair. Improvements in imaging now allow for identification of tear location, with femoral-sided injuries, being more suitable for repair. We will discuss in details strategies for improving the mechanical and biological environment in order to allow primary healing to occur.

In particular, we will explain mechanical supplementation such as Internal Brace Ligament Augmentation and Dynamic Intraligamentary Stabilisation techniques. These are novel techniques that aim to protect the primary repair by providing a stabilising construct that connects the femur and the tibia, thus bridging the repair.

Bio enhanced repair

In addition, biological supplementation is being investigated as an adjunct and we will review the current literature with regards to bio-enhancement in the form platelet rich plasma, bio-scaffolds and stem cells. On the basis of current evidence, there appears to be a role for bio-enhancement, however, this is not yet translated into clinical practice.

Conclusions

Several promising avenues of further research now exist in the form of mechanical and biological augmentation techniques. Further work is clearly needed but there is renewed interest and focus for primary ACL repair that may yet prove the new frontier in ligament repair.