Anterior cruciate ligament reconstruction: principles of treatment

Femoral Tunnel Widening After Double-Bundle Anterior Cruciate Ligament Reconstruction With Hamstring Autograft Produces a Small Shift of the Tunnel Position in the Anterior and Distal Direction: Computed Tomography-Based Retrospective Cohort Analysis

PURPOSE

To determine whether the femoral tunnel position remains in an anatomical footprint after tunnel widening and shifting.

METHODS

Patients who underwent unilateral double-bundle anterior cruciate ligament reconstruction with hamstring autograft and performed computed tomography scan evaluation at the time of 5 days and 1 year postoperatively were included in this retrospective cohort study. Three-dimensional models of the femur and femoral tunnels were reconstructed from computed tomography scan data. The location of the tunnel center and tunnel margins in the anatomical coordinate system, and the mean shifting distance of tunnel center and margin were measured with image analysis software during the period. The change of tunnel center location in Bernard quadrant was confirmed if the tunnel center remained within the boundaries of anatomical position after tunnel widening.

RESULTS

A total of 56 patients satisfied the inclusion criteria. The mean shifting distance of AM and PL tunnel centers were 1.7 ± 0.9 mm and 1.6 ± 0.6 mm. The Tunnel margin of the anteromedial (AM) and posteromedial (PL) tunnels were shifted to 2.5 ± 1.3 mm and 2.6 ± 1.4 mm in the anterior direction, and 1.4 ± 0.9 mm and 1.0 ± 0.7 mm in the distal direction, respectively. Among the anatomical located tunnel, 97% (32/33) and 87.1% (27/31) of AM and PL tunnel centers remained in a range of anatomical footprint. The tunnel center was shifted from the anatomical position into a nonanatomical position in 3% (1/33) of the AM tunnel and 12.9% (4/31) of PL tunnel after tunnel widening. The tunnel location which shifted nonanatomically were relatively anterior and distal position.

CONCLUSIONS

Tunnel widening shifts the tunnel position to the anterior and distal direction, which could change the initial tunnel position. Nevertheless, the majority of tunnel positions remained in the anatomical position after tunnel widening and shifting.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

A Systematic Review of Randomized Controlled Trials in Anterior Cruciate Ligament Reconstruction: Standard Techniques Are Comparable (299 Trials With 25,816 Patients)

PURPOSE

To provide an overview of all published randomized controlled trials (RCTs) in anterior cruciate ligament reconstruction (ACLR) summarizing the available evidence.

METHODS

Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we searched the Cochrane FIGCentral Register of Controlled Trials, Ovid MEDLINE, and Embase for RCTs of ACLR from their inception to August 26, 2020. Outcome measure was whether RCTs reported statistically significant findings. RCTs were then classified according to their intervention groups in a narrative synthesis of the evidence.

RESULTS

In total, 299 RCTs met the inclusion criteria and were included with a total number of 25,186 patients. Only 30 RCTs (10%) reported significant differences between the intervention and the control groups. These included 101 RCTs on grafts, 20 RCTs on tunnel placements, 48 RCTs on graft fixation, 42 RCTs on single-bundle compared with double-bundle reconstructions, 11 RCTs on additional procedures, 11 RCTs on graft tensioning, 5 RCTs on timing of surgery, 25 RCTs on technical variations from standard techniques, 6 RCTs on ACL repair, 5 RCTs on navigation, 16 RCTs on perioperative management, and 9 RCTs on other aspects of ACLR. Only 14 RCTs (4.7%) reported outcomes beyond 10 years with greater allograft failures compared with autografts, high incidence of osteoarthritic changes in reconstructed knees (22%-100%), with no significant differences in outcomes between bioabsorbable or metal screws for graft fixation, patellar versus hamstrings or single- versus double-bundle reconstructions.

CONCLUSIONS

The evidence indicates that a standard arthroscopic single- or double-bundle ACLR with hamstrings/patella autografts, transportal technique, and fixation techniques familiar to the surgeon leads to comparable results. This evidence offers surgeons the flexibility to use standard and cost-effective techniques and achieve comparable outcomes.

LEVEL OF EVIDENCE

Level II; systematic review of Level I-II randomized controlled trials.

Postoperative Rehabilitation of Anterior Cruciate Ligament Reconstruction: A Systematic Review

Recent studies have investigated the various components of postoperative rehabilitation protocols following anterior cruciate ligament reconstruction (ACLR). The objective of this article was to access and summarize the latest evidence for postoperative rehabilitation protocols following ACLR to evaluate common timeframes, number of phases, exercises, as well as the length of rehabilitation protocol. Common interventions include vibration training, open-chain and closed-chain exercises, electrical stimulation, postoperative bracing, and aquatic therapy. The eligibility criteria included English-language articles published from 2000 to 2019 pertaining to rehabilitation following ACLR, excluding addresses, commentaries, and editorials. Two blinded reviewers screened, graded, and extracted data from articles. Recommendations on various aspects of rehabilitation were summarized. A total of 3651 articles were retrieved from the database search, and 62 level 1 to 2 studies were available for extraction. On the basis of the evidence, vibration training can be safely incorporated into the postoperative rehabilitation protocol following ACLR. Accelerated rehabilitation may give patients short-term functional benefits. Open kinetic chain exercises may have additional strength and endurance benefits. Postoperative bracing does not confer additional benefits. Long-term use of neuromuscular electrical stimulation seems to be more beneficial than short-term use. Aquatic rehabilitation may be beneficial in the early phases of anterior cruciate ligament rehabilitation.

Bone Mesenchymal Stem Cells Contribute to Ligament Regeneration and Graft-Bone Healing after Anterior Cruciate Ligament Reconstruction with Silk-Collagen Scaffold

Anterior cruciate ligament (ACL) reconstruction was realized using a combination of bone mesenchymal stem cells (BMSCs) and silk–collagen scaffold, and an in vivo evaluation of this combination was performed. By combining type I collagen and degummed silk fibroin mesh, silk–collagen scaffolds were prepared to simulate ligament components. BMSCs isolated from bone marrow of rabbits were cultured for a homogenous population and seeded on the silk–collagen scaffold. In the scaffold and BMSC (S/C) group, scaffolds were seeded with BMSCs for 72 h and then rolled and used to replace the ACL in 20 rabbits. In the scaffold (S) group, scaffolds immersed only in culture medium for 72 h were used for ACL reconstruction. Specimens were collected at 4 and 16 weeks postoperatively to assess ligament regeneration and bone integration. HE and immunohistochemical staining (IHC) were performed to assess ligament regeneration in the knee cavity. To assess bone integration at the graft–bone interface, HE, Russell–Movat staining, micro-CT, and biomechanical tests were performed. After 4 weeks, vigorous cell proliferation was observed in the core part of the scaffold in the S/C group, and a quantity of fibroblast-like cells and extracellular matrix (ECM) was observed in the center part of the graft at 16 weeks after surgery. At 4 and 16 weeks postoperatively, the tenascin-C expression in the S/C group was considerably higher than that in the S group (4 w, p < 0.01; 16 w, p < 0.01). Furthermore, bone integration was better in the S/C group than in the S group, with histological observation of trabecular bone growth into the graft and more mineralized tissue formation detected by micro-CT (4 w, bone volume fraction (BV/TV), p = 0.0169, bone mineral density (BMD), p = 0.0001; 16 w, BV/TV, p = 0.1233, BMD, p = 0.0494). These results indicate that BMSCs promote ligament regeneration in the knee cavity and bone integration at the graft–bone interface. Silk–collagen scaffolds and BMSCs will likely be combined for clinical practice in the future.

Arthroscopic Primary Repair of the Posterior Cruciate Ligament

The posterior cruciate ligament (PCL) is one of the four major stabilizers of the knee joint and functions as the primary restraint to posterior tibial translation. PCL tears rarely occur in isolation and most commonly presents in the setting of multiligamentous knee injuries. Several treatment strategies for these injuries have been proposed over the last decades, including ligament reconstruction and primary repair. Arthroscopic primary PCL repair has the potential to preserve native tissue using a more minimally invasive approach, thereby avoiding donor-site morbidity and allowing early mobilization. While arthroscopic PCL repair is certainly not an effective surgical approach for all patients, this procedure may be a reasonable and less morbid alternative to PCL reconstruction in selected patients treated for proximal or distal avulsion tears, with low failure rates, good knee stability, and good to excellent subjective outcomes. The surgical indications, surgical techniques, postoperative management, and outcomes for arthroscopic primary repair of proximal and distal PCL tears will be discussed in this review.

Anterolateral ligament reconstruction improves the clinical and functional outcomes of anterior cruciate ligament reconstruction in athletes

PURPOSE

To compare the outcomes of anterior cruciate ligament (ACL) reconstruction with those of combined ACL and anterolateral ligament (ALL) reconstruction in ACL-deficient knees. The objective of this study was to improve knowledge regarding the treatment of ACL-deficient knees with combined ACL and ALL reconstruction. Combined ACL and ALL reconstruction has been hypothesized to result in better clinical and functional outcomes than isolated ACL reconstruction (ACLR).

METHODS

One-hundred and seven adult male athletes with ACL tears and high-grade pivot shifts were randomized into two groups. Those in group A (n = 54) underwent ACLR, while those in group B (n = 53) underwent combined ACL and ALL reconstruction. The median age was 26 (18-40) and 24 (18-33) years in groups A and B, respectively, and the median follow-up was 60 (55-65) months. Physical examination findings, instrumented knee laxity tested using a KT-1000 arthrometer, and International Knee Documentation Committee Scale (IKDC) scores were used to evaluate the outcomes.

RESULTS

One-hundred and two patients were available for follow-up: 52 in group A and 50 in group B. Postoperatively, the pivot shift was normal in 43 (82.7%) and 48 (96%) patients in groups A and B, respectively (p < 0.001). The median instrumented knee laxity was 2.5 ± 0.7 (1.2-6.1) mm in patients in group A and 1.2 ± 0.7 (1.2-3.2) mm in patients in group B (p < 0.001). Additionally, 44 (84.6%) patients in group A had normal IKDC scores and 3 (5.8%) had nearly normal scores, while 48 (96.0%) patients in group B had normal IKDC scores and 2 (4%) had nearly normal scores (p < 0.001).

CONCLUSION

Combined ACL and ALL reconstruction, compared with isolated ACLR resulted in favourable clinical and functional outcomes, as demonstrated by decreased rotational instability and instrumented knee laxity, a lower graft rupture rate and better postoperative IKDC scores.

LEVEL OF EVIDENCE

1.

Peroneus Longus Tendon Autograft for Anterior Cruciate Ligament Reconstruction: A Safe and Effective Alternative in Nonathletic Patients

Introduction

Anterior cruciate ligament (ACL) is a common injury which has been conventionally managed by various graft reconstruction using bone patellar tendon bone, or quadruple hamstring autograft, to name a few. However, all these grafts are associated with many complications. Lately, peroneus longus tendon (PLT) autograft has shown promising results in this field, although there is still a dearth of data on its use. We, therefore, aimed at carrying out a study to evaluate the functional outcome and knee stability results of ACL reconstruction using PLT graft.

Patients and Methods

Patients with a completely torn ACL were included in the study. The PLT was harvested, and graft length, thickness, and harvesting time were noted intraoperatively. Knee stability and functional scores were evaluated clinically and using Lachman test (primarily) and KT-2000 arthrometer and subjectively with International Knee Documentation Committee (IKDC) score at 6, 12, and 24 months (secondary outcome) postoperatively. Ankle scores were also recorded by making use of American Orthopedic Foot and Ankle Score (AOFAS)-Hindfoot Scale.

Results

Forty-eight patients met the inclusion criteria. The graft harvest time was 7.4 min (5-9 min). The mean thickness of the graft on doubling was 7.9 mm (7-9 mm). Ninety-six percent of the patients were satisfied with their results of the knee surgery, and 95% of the patients had no complaints of ankle joint. The mean IKDC score postoperatively was 78.16 ± 6.23, and the mean AOFAS score was 98.4 ± 4.1. None of the patients had any neurovascular deficit.

Conclusion

ACL reconstruction using PLT graft yields a good functional score (IKDC, KT-2000 arthrometer) even at 2-year follow-up. It is a safe and effective autograft option for ACL reconstruction.

Original study: early patient-reported functional outcome of all-inside ACL reconstruction as compared to anteromedial portal technique

BACKGROUND

Anteromedial portal technique (AMP) using hamstring autograft is a popular technique of arthroscopic ACL reconstruction allowing anatomical placement of femoral. In this technique, a cortical suspensory fixation of graft is used on the femoral side and interference screw fixation on the tibial side using a complete bone tunnel. All-inside translateral technique is a recently introduced technique which uses a closed loop of quadrupled semitendinosus graft with an adjustable cortical suspensory fixation on both sides allowing optimum tensioning of graft and near-complete filling of retrosockets created by the flip cutter on both femoral and tibial sides. With its proposed but unproven benefits, our study was planned to compare the two techniques.

METHODS

A total of 80 young active males requiring ACL reconstruction surgery were equally randomized to AMP and All-inside technique. The primary objective of the study was to compare the ability to return to pre-injury level of activity using Tegner activity scale and patient-reported outcome using new Knee Society Score (KSS) at two years of follow-up.

RESULTS

The mean improvement in Tegner score was significantly better (p = 0.0005) in all-inside group (2.34 ± 0.97) as compared to AMP group (1.5 ± 1.30). Among components of new KSS, patient satisfaction was better in all-inside group.

CONCLUSION

All-inside ACL reconstruction provides a better chance of return to pre-injury level of activity with accompanied patient satisfaction as compared to AMP technique at two years of follow-up.

LEVEL OF EVIDENCE

Level I, therapeutic study.

The Impact of Resident Involvement on Surgical Outcomes following Anterior Cruciate Ligament Reconstruction

Hands-on participation in the operating room (OR) is an integral component of surgical resident training. However, the implications of resident involvement in many orthopaedic procedures are not well defined. This study aims to assess the effect of resident involvement on short-term outcomes following anterior cruciate ligament reconstruction (ACLR). The National Surgical Quality Improvement Program (NSQIP) database was queried to identify all patients who underwent ACLR from 2005 to 2012. Demographic variables, resident participation, 30-day complications, and intraoperative time parameters were assessed for all cases. Resident and nonresident cases were matched using propensity scores. Outcomes were analyzed using univariate and multivariate regression analyses, as well as stratified by resident level of training. Univariate analysis of 1,222 resident and 1,188 nonresident cases demonstrated no difference in acute postoperative complication rates between groups. There was no significant difference in the incidence of overall complications based on resident level of training (p = 0.109). Operative time was significantly longer for cases in which a resident was involved (109.5 vs. 101.7 minutes; p < 0.001). Multivariate analysis identified no significant predictors of major postoperative complications, while patient history of chronic obstructive pulmonary disease was the only independent risk factor associated with minor complications. Resident involvement in ACLR was not associated with 30-day complications despite a slight increase in operative time. These findings provide reassurance that resident involvement in ACLR procedures is safe, although future investigations should focus on long-term postoperative outcomes.

Relation of peroneus longus autograft dimensions with anthropometric parameters in anterior cruciate ligament reconstruction: Importance of the distal leg diameter

Objectives

This study aims to investigate the relationship between various anthropometric parameters and the diameter and length of the peroneus longus tendon (PLT) graft in the anterior cruciate ligament (ACL) reconstruction.

Patients and methods

A total of 52 patients (38 males, 14 females; mean age: 29.2±7.7 years; range, 17 to 51 years) who received PLT autograft for ACL reconstruction in our center between July 2018 and June 2020 were retrospectively analyzed. Demographic characteristics of the patients and leg length, and proximal and distal leg diameters were recorded before the operation. The PLT autograft diameter and length were measured during surgery.

Results

A statistically significant correlation was found between the graft diameter and length and weight, height, body mass index (BMI), leg length, and proximal and distal leg diameters (p<0.01). There was no statistically significant correlation between the graft diameter and length and age (p>0.05). Distal leg diameter had the highest correlation coefficient for the PLT autograft diameter (r=0.956), while the height had the highest correlation coefficient for the PLT autograft length (r=0.982).

Conclusion

Anthropometric parameters of height, weight, BMI, leg length, and proximal and distal leg diameters may be helpful for surgeons to predict the diameter and length of the PLT autograft before surgery. Distal leg diameter is a particularly important parameter in predicting PLT autograft diameter.

Allograft for Anterior Cruciate Ligament Reconstruction (ACLR): A Systematic Review and Meta-Analysis of Long-Term Comparative Effectiveness and Safety. Results of a Health Technology Assessment

Purpose

To evaluate whether allograft anterior cruciate ligament reconstruction (ACLR) is superior or inferior to autograft ACLR or conservative management in terms of effectiveness and safety.

Methods

A systematic review of the evidence for allograft ACLR was conducted. Randomized controlled trials with a minimum mean follow-up time of 5 years were included. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and the EUnetHTA-Core-Model were used as reporting standards. A meta-analysis was conducted for selected crucial outcomes using a random-effects model. The strength of the available evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach.

Results

Six randomized trials were included comparing allograft with autograft. Patients were on average between 28 and 32.8 years of age (allograft group) and 28.9 and 31.7 years of age (autograft group). Based on the crucial outcomes, the meta-analyses showed no statistically significant differences in Lysholm score, Tegner score, and Cincinnati Knee Score between groups. A small statistical difference favoring autografts was found across studies in the subjective International Knee Documentation Committee score (–2.25; 95% confidence interval –3.02 to –1.47; I² = 0%; range of all scores: 73.7-90). Two of six studies reported on graft failure, with a statistically significant difference to the detriment of using allografts (13/49 [26.5%] vs 4/48 [8.3%] in one study, 13/43 [30.2%] vs 3/40 [7.5%] in the other study).

Conclusions

Although no substantial difference in patient-reported function, activity level, and symptoms was demonstrated, evidence from the included studies showed a greater risk for graft failure or revision that may make allograft a less safe treatment modality in ACLR. The strength of available evidence is low based on the crucial outcomes due to the lack of high-quality research and the present increased risk of bias in primary studies. Priority should be shifted toward reflecting on whether there is a subpopulation for whom allograft ACLR may still be advantageous in theory (e.g., less-active older patients) and further conduct RCTs in this population.

Level of Evidence

Level II, systematic review of Level II evidence studies.

Clinical and radiological outcome after anterior cruciate ligament reconstruction using the T-lock Osteotrans resorbable tendon anchor: early experience and midterm follow-up

PURPOSE

Reconstruction of the Anterior cruciate ligament (ACL) using tendon grafting is an established method for restoring knee function and stability. Multiple methods are established for graft fixation. Several involve anchoring the autograft distant to the joint with hardware that remains implanted. This study reports the first early to midterm results in patients who received ACL reconstruction (ACLR) using the T-Lock Osteotrans femoral near joint fixation method with a tibial fixation using the BioactIF Osteotrans interference screw.

METHODS

This consecutive prospective series included 20 Patients (14 Male, 6 Female) with a primary ACL rupture. All patients were treated with an ACLR using a semitendinosus autograft fixated with the T-Lock Osteotrans and were followed-up postoperatively. The following parameters were assessed: Side-to-side difference of the posterior-anterior translation measured using the KT-1000 arthrometer, Tegner activity score, Lysholm score, IKDC subjective knee evaluation form. Magnetic resonance imaging (MRI) was done to assess tunnel enlargement and integrity of the anchoring device.

RESULTS

The average follow-up duration was 2 years (range 1-4.2 years). One patient was lost to follow-up. Two Patients suffered a traumatic ACL re-rupture 2 years postoperatively and received a 2-stage revision ACLR. Difference in the posterior-anterior translation was 1.8 mm (range 0-5). The median Tegner score was 6 (range 4-10) and 9 patients (45%) returned to their preinjury level of activity. The mean IKDC subjective knee evaluation form scored 91 points (range 77-100). The mean Lysholm score was 86 points (74-96). All mentioned scores were significantly better compared to preoperative values. No relevant tunnel enlargement was seen on MRI. The anchoring device was evaluated to be intact in all patients.

CONCLUSION

ACLR with the aforementioned procedure leads to good clinical and radiological outcome.

How to Achieve an Accurate Anatomical Femoral Tunnel Technique in ACL Reconstruction in the Early Years of Your Consultancy? Femoral Offset Aimer Technique: Consistent and Reproducible Technique

Femoral tunnel malposition is the most common reason for failure of primary anterior cruciate ligament reconstruction. There are several methods to identify the anatomical location of femoral footprint. Femoral offset aimer technique is one such technique which is easy to use and reliable. It is an ideal technique for junior and inexperienced surgeons to recreate the femoral tunnel in its anatomical footprint. The senior author (P.E.) has been using this technique for 30 consecutive cases in his first year of independent practice during his consultancy without any major intraoperative complications. The author describes this technique in this article with tips and tricks which will especially guide the junior and inexperienced surgeons to avoid running into intraoperative problems while drilling the femoral tunnel.

Comparison of the effectiveness of autologous grafts for anterior cruciate ligament reconstruction: A protocol for an overview of systematic review and network meta-analysis

BACKGROUND

Anterior cruciate ligament rupture is a common motor system injury, and the most effective treatment is anterior cruciate ligament reconstruction (ACLR). Choosing the right graft is an important factor to ensure the success of the surgery. Current research shows that the clinical effect of autologous ligaments is better than that of allogeneic ligaments and artificial ligaments. However, there are differences between the autogenous ligaments, and how to choose them is still controversial. This study evaluated the published systematic reviews on the efficacy of different autologous ligament grafts in ACLR, and based on this, conducted a network meta-analysis of related randomized controlled trials.

METHODS

We searched 8 international and Chinese databases including PubMed, Embase, Web of Science, and Cochrane Library. The methodological quality of systematic reviews will be evaluated by Assessing the Methodological Quality of Systematic Reviews-2 (AMSTAR2) measurement tool. Cochrane's risk of bias tool will be used to assess the risk of bias of included randomized controlled trials, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach will be used to evaluate the evidence quality. Network meta-analysis will be applied to evaluate the therapeutic effect of different autologous grafts. The main outcome measures are IKDC score, clinical failure rate, Lachman test, Lysholm score, and the incidence of complications. Odds ratio and its 95% confidence interval will be used to synthesize the dichotomy results, while the mean difference and 95% confidence interval of continuous variables will be used for continuous variables.

RESULTS

This study will provide comprehensive evidence for the application of autologous grafts in ACLR.

CONCLUSION

The results of this study will help clinicians make appropriate decisions.

PROTOCOL REGISTRATION NUMBER

INPLASY202090061.

Returning to Sport After Anterior Cruciate Ligament Reconstruction in Physically Active Individuals

Background Physically active individuals are susceptible to sports injuries, one of which is anterior cruciate ligament (ACL) injury. ACL injury can be managed conservatively or by surgical reconstruction. Returning to sport (RTS) after ACL injury is one of the main goals of ACL reconstruction (ACLR). However, rates of return vary and can be affected by several factors. The objectives of this study were to estimate the rate of return and to identify the factors that might affect RTS after ACLR.  Methods This was a cross-sectional study, including individuals who had an ACLR. Participants were sent an online survey included questions about their injury, sport participation, International Knee Documentation Committee form (IKDC), and the Tampa Scale for Kinesiophobia (TSK-11). Participants who had their surgery in the period between January 2011 to December 2018 and participated in sports regularly were included. Descriptive statistics were performed. Chi-square and student t-tests were performed to explore the differences between participants who returned and the ones that did not.  Results A total of 93 participants were included. The majority (69.9%) were playing soccer before the injury. Though more than half (61.3%) returned to sports, only 29% participated at the same level before the injury. Fear of reinjury was the most frequent reason for delaying or not returning (30%), followed by pain (29). Significantly better IKDC (p=0.002) and TSK-11 (p<0.001) scores were noted in participants who had returned to sports. On the other hand, participants' age, body mass index (BMI), time from injury to surgery, time since surgery, and times of sports participation per week were not found to be significantly different between those who returned versus those who did not. Conclusion The participants in this study had a low rate of return with fear of reinjury being the most common reason not to return. However, a participant's IKDC and TSK-11 scores were associated factors for RTS, thus optimizing those factors after surgery is crucial.

Developmental changes in ACLs and semitendinosus tendons dimensions according to age in children

PURPOSE

Managing anterior cruciate ligament (ACL) injuries in skeletally immature patients remains difficult. The main aim of this study was to retrospectively compile normative data on the cross-sectional area (CSA) of the semitendinosus tendon (ST) and the diameter of the ACL in children and young adults.

METHODS

Knee magnetic resonance imaging (MRI) examinations were performed for a 2-year period in 132 patients (83 female and 49 male patients). The mean age was 14.9 years (8-18 years). Measurements of the ST CSA were performed on axial views in greyscale by two independent researchers. The ACL diameter was measured as well.

RESULTS

The results show the CSA of the ST was related to age, and its growth was not linear. The highest growth rate of the CSA of the ST occurred at age 12-13 at the level of the femoral growth plate and at the level of the tibial plateau. The growth of the ACL diameter was linear until 18 years of age.

CONCLUSIONS

ST growth (measured in CSA increments) is almost complete at the age of 13, even though the growth is not linear. ACL growth measured in diameter increments proceeds linearly from 8 to 18 years of age. MRI is a clinically useful tool for assessing hamstring tendon grafts preoperatively.

LEVEL OF EVIDENCE

Level III, diagnostic studies.

Changes in hamstring strength after anterior cruciate ligament reconstruction with hamstring autograft and posterior cruciate ligament reconstruction with tibialis allograft

Aim

The aim of this study was to evaluate the changes in hamstring strength both after anterior cruciate ligament reconstruction (ACLR) with hamstring autograft followed by early rehabilitation and posterior cruciate ligament reconstruction (PCLR) with tibialis allograft followed by delayed rehabilitation.

Methods

Isokinetic strengths of the quadriceps and hamstring muscles and endurances were compared between a group of 20 patients undergoing PCLR using a tibialis anterior allograft and a 1:2 matched control group of 40 patients undergoing ACLR using a hamstring autograft at 2 years after the operations. Clinical results were also compared using stability tests and the Lysholm and the International Knee Documentation Committee scores.

Results

At 2 years after the operations, the torque deficit of the hamstring muscle in the involved leg compared to the uninvolved leg at both 60°/s and 120°/s was greater in the PCLR group than in the ACLR group (60°/s, 21.8 ± 14.0% versus 1.9 ± 23.9%, P = 0.0171; 120°/s, 15.3 ± 13.7% versus −0.7 ± 17.4%, p = 0.012, respectively). The peak torque of the hamstring muscle at 120°/s was significantly lower in the involved leg than in the uninvolved leg only in the PCLR group (71.3 ± 31.9 N∙m versus 81.9 ± 27.8 N∙m, P = 0.005). There was no significant difference in the clinical results between the groups except for a side-to-side difference in the tibial translation on Telos stress radiographs.

Conclusion

The strength of the hamstring of the PCLR leg with allograft was significantly weaker than that of the unoperated leg after 2 years, whereas that of the ACLR leg with hamstring autograft maintained a similar level of strength compared to that of the uninvolved leg.

Level of evidence

Level III, case–control study.

PATIENTS FOCUS ON PERFORMANCE OF PHYSICAL ACTIVITY, KNEE STABILITY AND ADVICE FROM CLINICIANS WHEN MAKING DECISIONS CONCERNING THE TREATMENT OF THEIR ANTERIOR CRUCIATE LIGAMENT INJURY

BACKGROUND

When deciding medical treatment, patients' perspectives are important. There is limited knowledge about patients' views when choosing non-operative treatment or anterior cruciate ligament (ACL) reconstruction (ACLR) after ACL injury.

PURPOSE

To describe reasons that influenced patients' decisions for non-operative treatment or ACLR after ACL injury.

STUDY DESIGN

Cross-sectional study.

METHODS

This study recruited a total of 223 patients (50% men), aged 28 ± 8 years who had sustained ACL injury, either unilateral or bilateral. Subjects were, at different time points after injury, asked to fill out a questionnaire about their choice of treatment, where an ACLR treatment decision was made, some responded before and some after the ACLR treatment. A rating of the strength of 10 predetermined reasons in their choice of treatment graded as 0 (no reason) to 3 (very strong reason), was done.

RESULTS

Patients with unilateral ACL injury treated with ACLR (110 patients) rated "inability to perform physical activity at the same level as before the injury due to impaired knee function" (96%), "fear of increased symptoms during activity" (87%) and "giving way episodes" (83%) as strong or very strong reasons in their treatment decision. Patients with bilateral ACL injury treated with ACLR (109 knees) rated similar reasons as patients with unilateral ACLR and also "low confidence in the ability to perform at the preinjury activity level without ACLR" (80%) as strong or very strong reasons. Patients with unilateral ACL injury treated non-operatively (46 patients) rated "advice from clinician" (69%) as a strong or very strong reason. Patients with bilateral ACL injury treated non-operatively (25 knees) rated "absence of giving way episodes" (62%), and "no feeling of instability" (62%) as strong or very strong reasons.

CONCLUSION

Inability to perform physical activity, fear of increased symptoms, and giving way episodes were reasons that patients with ACL injury considered when making decisions about ACLR. When choosing non-operative treatment, patients considered the absence of instability or giving way symptoms, being able to perform physical activity, and advice from clinicians.

LEVEL OF EVIDENCE

4.

Awareness and knowledge about anterior cruciate ligament injury among the general adult population of Saudi Arabia

Background:

The literature shows that data regarding the Saudi public's knowledge about anterior cruciate ligament (ACL) injury is still limited.

Aims:

This study aimed to determine the knowledge toward ACL injury in the general population of Saudi Arabia, as well as to investigate the main sources of information about ACL among the public.

Materials and Methods:

A cross-sectional online survey was conducted among a sample of 408 participants from all regions of Saudi Arabia. All participants completed an anonymous self-administered questionnaire, which included questions about their sociodemographic details and a structured tool to measure their knowledge about ACL injuries.

Results:

The present study showed that among 408 participants, 233 (57.1%) had adequate knowledge about ACL injuries, and 253 (62.0%) appreciated the seriousness of ACL injuries. The level of knowledge about ACL injuries was significantly associated with higher educational level (P = 0.000), but not with sex (P = 0.424) and region of residence (P = 0.404). Most of the participants agreed that ACL injury is a multi-factorial condition that results from a combination of factors, including sports, lack of warm-up before exercise, car accidents, old age, and lifting heavy objects. Internet, TV, and books were the most common sources of information about ACL injuries.

Conclusions:

While over half of the participants were aware of ACL injury, its seriousness, and its common risk factors, there are still knowledge gaps regarding ACL injury symptoms. Therefore, we recommend increasing public awareness about ACL injury, specifically through health education websites and TV programs.

Hypnosis as an Approach to Control Pain and Anxiety in Anterior Cruciate Ligament Reconstruction and Meniscal Surgeries: Two Case Presentations

Anterior cruciate ligament (ACL) reconstruction is an extremely common surgery in sports medicine and orthopedic surgery. This surgery requires creating tunnels in bones (femur and tibia), which is often associated with severe pain and thus general or neuraxial anesthesia should be applied to mitigate pain and anxiety. This paper follows our previous case report of hypnoanesthesia in hand surgery, discussing the application of hypnosis as a non-pharmacologic intervention for controlling intraoperative and postoperative pain and anxiety, which can contribute to postoperative recovery of patients with ACL surgery. According to the results of this study, it seems better to teach hypnosis as a pain control protocol to anesthesia residents and pain service staff. Also, hypnosis can be considered an anxiety reduction strategy in perioperative phases and also useful for postoperative pain management.

Lower extremity kinematic analysis in male athletes with unilateral anterior cruciate reconstruction in a jump-landing task and its association with return to sport criteria

Background

Return to sport (RTS) criteria are widely being used to identify anterior cruciate ligament reconstructed (ACLR) athletes ready to return to sportive activity and reduce risk of ACL re-injury. However, studies show a high rate of ACL re-injury in athletes who passed RTS criteria. This indicates that the current RTS criteria might not be sufficient to determine return to sport time in ACLR athletes. Previous studies have reported a close association between altered lower limb kinematics and ACL re-injury. However, it is not clear how lower extremity kinematics differs between ACLR athletes who passed the RTS-criteria and who failed. This study compared lower extremity kinematics in a jump-landing task between ACLR athletes who passed the RTS criteria (Limb symmetry in hop tests, quadriceps strength and questionnaires) to those who failed and to the healthy individuals.

Methods

Participants were 27 male football players with unilateral ACLR including 14 who passed -RTS criteria and 13 failed, and 15 healthy football players. A 3D motion capture system recorded participants’ lower extremity motion while performing 10 trials of a bilateral jump-landing task. Hip, knee and ankle angular motion were examined at initial contact. Two-way mixed analysis of variances (2 limbs × 3 groups) and Bonferroni post-hoc tests were performed to compare the joint angles between the limbs and groups.

Results

lower hip abduction angle was found in the failed (involved limb 4.1 ° ± 4.2) and passed RTS (involved limb 6.8° ± 3.3) groups compared to the healthy group (non-dominant limb 10.7° ± 3.7). Ankle inversion in the failed RTS (0.4° ± 4.9) group was significantly lower than both passed RTS (4.8° ± 4.8, p = 0.05) and healthy (8.2° ± 8.1, p < 0.001) groups. There were no significant differences between the groups in knee kinematics.

Conclusions

Our findings indicate reduced hip abduction during initial contact phase of landing in athletes returned to sport. Reduced hip abduction during the complex multiplanar movement of jump-landing is a risk factor for ACL re-injury. Current RTS criteria may not be sufficient to identify ACLR athletes at high risk of re-injury. The kinematic analysis in conjunction with current RTS criteria can provide additional insight into the return to sport decision making.

Rates of Adverse Outcomes and Revision Surgery After Anterior Cruciate Ligament Reconstruction: A Study of 104,255 Procedures Using the National Hospital Episode Statistics Database for England, UK

BACKGROUND

After an anterior cruciate ligament (ACL) injury, ACL reconstruction is an elective procedure, and therefore, an understanding of the attributable risk from undergoing ACL reconstruction is necessary for patients to make a fully informed treatment decision.

PURPOSE

To determine the absolute risk of adverse outcomes including reoperation after ACL reconstruction with comparison, where possible, to the rate of adverse events reported in the general population.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

National hospital data on all ACL reconstructions performed in England between April 1, 1997, and March 31, 2017, were analyzed. Revision cases, bilateral procedures within 6 months, and cases with concurrent cartilage or multiple ligament surgery were excluded. The primary outcome was the occurrence of at least 1 serious complication (myocardial infarction, stroke, pulmonary embolism, infection requiring surgery, fasciotomy, neurovascular injury, or death) within 90 days. Additionally, 5-year rates of revision ACL reconstruction, contralateral ACL reconstruction, and meniscal surgery were investigated.

RESULTS

There were 133,270 ACL reconstructions performed, of which 104,255 were eligible for analysis. Within 90 days, serious complications occurred in 675 (0.65% [95% CI, 0.60-0.70]), including 494 reoperations for infections (0.47% [95% CI, 0.43-0.52]) and 129 for pulmonary embolism (0.12% [95% CI, 0.10-0.15]). Of 54,275 procedures with at least 5 years' follow-up, 1746 (3.22% [95% CI, 3.07-3.37]) underwent revision ACL reconstruction in the same knee, 1553 underwent contralateral ACL reconstruction (2.86% [95% CI, 2.72-3.01]), and 340 underwent meniscal surgery (0.63% [95% CI, 0.56-0.70]). The overall risk of serious complications fell over time (adjusted odds ratio [OR], 0.96 per year [95% CI, 0.95-0.98]); however, older patients (adjusted OR, 1.11 per 5 years [95% CI, 1.07-1.16]) and patients with a greater modified Charlson Comorbidity Index (adjusted OR, 2.41 per 10 units [95% CI, 1.65-3.51]) were at a higher risk. For every 850 (95% CI, 720-1039) ACL reconstructions, 1 pulmonary embolism could be provoked. For every 213 (95% CI, 195-233), 1 native knee joint infection could be provoked.

CONCLUSION

The overall risk of adverse events after ACL reconstruction is low; however, some rare but serious complications, including infections or pulmonary embolism, may occur. Around 3% of patients undergo further ipsilateral or contralateral ACL reconstruction within 5 years. These data will inform shared decision making between clinicians and patients considering their treatment options.

Italian consensus statement for the use of allografts in ACL reconstructive surgery

PURPOSE

Graft choice for primary anterior cruciate ligament reconstruction (ACL-R) is debated, with considerable controversy and variability among surgeons. Autograft tendons are actually the most used grafts for primary surgery; however, allografts have been used in greater frequency for both primary and revision ACL surgery over the past decade. Given the great debate on the use of allografts in ACL-R, the "Allografts for Anterior Cruciate Ligament Reconstruction" consensus statement was developed among orthopedic surgeons and members of SIGASCOT (Società Italiana del Ginocchio, Artroscopia, Sport, Cartilagine, Tecnologie Ortopediche), with extensive experience in ACL-R, to investigate their habits in the use of allograft in different clinical situations. The results of this consensus statement will serve as benchmark information for future research and will help surgeons to facilitate the clinical decision making.

METHODS

In March 2017, a formal consensus process was developed using a modified Delphi technique method, involving a steering group (9 participants), a rating group (28 participants) and a peer-review group (31 participants). Nine statements were generated and then debated during a SIGASCOT consensus meeting. A manuscript has been then developed to report methodology and results of the consensus process and finally approved by all steering group members.

RESULTS

A different level of consensus has been reached among the topics selected. Strong agreement has been reported in considering harvesting, treatment and conservation methods relevant for clinical results, and in considering biological integration longer in allograft compared to autograft. Relative agreement has been reported in using allograft as the first-line graft for revision ACL-R, in considering biological integration a crucial aspect for rehabilitation protocol set-up, and in recommending a delayed return to sport when using allograft. Relative disagreement has been reported in using allograft as the first-line graft for primary ACL-R in patients over 50, and in not considering clinical results of allograft superior to autograft. Strong disagreement has been reported in using allograft as the first-line graft for primary ACL-R and for skeletally immature patients.

CONCLUSIONS

Results of this consensus do not represent a guideline for surgeons, but could be used as starting point for an international discussion on use of allografts in ACL-R.

LEVEL OF EVIDENCE

IV, consensus of experts.

Review of magnetic resonance imaging features of complications after anterior cruciate ligament reconstruction

The anterior cruciate ligament (ACL) is an important stabiliser of the knee and is commonly torn in sports injuries. Common indications for imaging after ACL reconstruction include persistent symptoms, limitation of motion and re-injury. Important postoperative complications include graft failure, impingement, arthrofibrosis and graft degeneration. This article aimed to familiarise the radiologist with magnetic resonance (MR) imaging appearances of properly positioned intact ACL grafts and to provide a comprehensive review of MR imaging features of complications following ACL reconstruction.

Anterior cruciate ligament reconstruction without the use of a tourniquet

INTRODUCTION

Anterior cruciate ligament tears are a common ligamentous knee injury and are usually managed with arthroscopic reconstruction surgery using a tourniquet. The employment of a tourniquet in the management of an anterior cruciate ligament tear has been a debatable topic for some time. Here, we discuss our technique in the reconstruction of anterior cruciate ligament tears without the use of a tourniquet.

MATERIALS AND METHODS

We performed 26 anterior cruciate ligament reconstruction surgeries using hamstring grafts without the use of a tourniquet. The outcomes measured were pain using the visual analogue scale, knee swelling, range of movement and bleeding.

RESULTS

Using this technique, we have noted considerable reduction in knee swelling and pain. In addition, there was considerable improvement in the range of movement postoperatively, and there were no bleeding complications noted.

CONCLUSIONS

We consider ACL reconstruction without a tourniquet to be an excellent alternative to conventional reconstruction with the use of tourniquet.

Advantages of an Attached Semitendinosus Tendon Graft in Anterior Cruciate Ligament Reconstruction in a Rabbit Model

BACKGROUND

The semitendinosus tendon graft with an intact tibial insertion has a sustainable blood supply and might be beneficial for graft maturation after anterior cruciate ligament reconstruction (ACLR); however, its potential advantages for graft tendon-bone healing is still unclear.

HYPOTHESIS

Intact tibial insertion of the hamstring tendon can preserve enough blood supply to keep the harvested tendon alive, which can improve tendon-bone healing and the biomechanical strength of the graft.

STUDY DESIGN

Controlled laboratory study.

METHODS

Sixty-four healthy New Zealand White rabbits underwent unilateral ACLR with a semitendinosus tendon autograft after random enrollment into 2 groups (study group, n = 32 rabbits with semitendinosus tendon-preserved tibial insertions; control group, n = 32 rabbits with free semitendinosus tendons). At weeks 3, 6, 12, and 24, 8 rabbits in each group were sacrificed to evaluate tendon-bone healing by histologic staining, micro-computed tomography (micro-CT) examination, and biomechanical test.

RESULTS

The grafts in the study group maintained a similar cell count with no signs of necrosis or hypocellularity across all time points, but the grafts in the control group underwent a characteristic stage of necrosis at weeks 3 and 6. Sharpey-like fibers were observed from postoperative 3 weeks at the tendon-bone interface in the study group, and a normal insertion-like structure was formed at week 12, which became more mature at week 24. In the control group, however, Sharpey-like fibers could not be observed until week 12, and a normal transition through cartilage from bone to tendon was not observed at any time point. Histologic scores of the tendon-bone interface in the study group were significantly higher than those in the control group at week 6 ( P = .04), week 12 ( P < .001), and week 24 ( P = .04). As compared with the control group via micro-CT, the study group had a significantly smaller bone tunnel area at week 6 ( P = .01) and larger bone volume/total volume at week 3 ( P = .0026) and week 6 ( P = .01). Also, the study group had a significantly higher failure load at weeks 12 and 24 (both P = .03) and a significantly higher stiffness at week 24 ( P < .001) versus the control group.

CONCLUSION

The semitendinosus tendon graft with an intact tibial insertion in ACLR would bypass the graft avascular necrosis stage, which improves tendon-bone healing and biomechanical strength.

CLINICAL RELEVANCE

An alive graft in ACLR could improve tendon-bone healing and the biomechanical strength of the graft, which might be beneficial to early and intensive rehabilitation after ACLR.

The clinical relevance of PCL index on the reconstruction of anterior cruciate ligament with hamstring tendon autograft

The posterior cruciate ligament index (PCL index) has been reported as a diagnostic and prognostic marker for anterior cruciate ligament (ACL) reconstruction. The clinical relevance of PCL index on the reconstruction of ACL with hamstring tendon autograft has not been described in the literature. The objective of this study is to evaluate the importance of the PCL index as a marker of anatomic reconstruction and of functional improvement of patients undergoing ACL reconstruction with HT autograft. Twenty-four patients were submitted to ACL reconstruction with HT autograft. The PCL index was assessed by magnetic resonance imaging before and after surgery. The functional evaluation was performed through the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form© and Knee Society Knee Scoring System© (IKS). Patients presented a significant positive variation of the PCL index, IKDC and IKS scores. There is no significant correlation between PCL index variation and IKDC and IKS scores (p > 0.05). Unlike other studies reporting a relationship between the PCL index, control of rotational kinematics, and functional improvement in patients undergoing ACL reconstruction with bone-patellar tendon-bone autograft, this study does not demonstrate this association. There is evidence in this study to show that the PCL index may be used as an anatomic reconstructive marker of ACL but not to predict the clinical outcome in this type of reconstruction.

Long-term Comparison of Semitendinosus and Gracilis Tendon Versus Patellar Tendon Autografts for Anterior Cruciate Ligament Reconstruction: A 17-Year Follow-up of a Randomized Controlled Trial

BACKGROUND

Short-term and mid-term differences between hamstring and patellar tendon autografts for anterior cruciate ligament (ACL) reconstruction are well documented. Systematic reviews highlight the lack of long-term results between the two grafts.

HYPOTHESIS

Seventeen years after ACL reconstruction, no difference will be found in functional outcome, quality of life, and graft failure between patients with patellar tendon (PT) or semitendinosus and gracilis tendon (STG) autografts; however, a significant difference will be seen in the prevalence of osteoarthritis.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

Sixty-four patients were included in this prospective study (32 in each group). A single surgeon performed primary ACL reconstruction in alternating sequence. Forty-eight patients (24 in each group) were evaluated 17 years after ACL reconstruction: A clinical assessment was made based on the International Knee Documentation Committee (IKDC) form, instrumented laxity was measured with KT-1000 arthrometer, and radiography of the operated knee was conducted and assessed for degenerative disease. The Lysholm questionnaire and the Short Form-36 version 2 questionnaire were filled out by the patients.

RESULTS

At the 17-year follow-up, no statistically significant differences were seen with respect to graft failure (2 reruptures in the semitendinosus and gracilis tendon [STG] group [6.3%] and 3 reruptures in the PT group [9.4%]) and functional outcome. Increased instrumented laxity (>3 mm) measured with KT-1000 arthrometer was seen in significantly more patients in the STG group (8 in the STG group compared with 2 in the PT group; P = .03) with a mean side-to-side difference of 2.17 ± 1.86 mm in the STG group compared with 1.33 ± 1.93 mm in the PT group. A significant difference was found in frequency of knee osteoarthritis (OA)-100% in the PT group compared with 71% in the STG group ( P = .004). Patients in the PT group tended to have higher grade OA according to the IKDC grading system, with an average grade of 1.46 in the PT group compared with 1 in the STG group ( P = .055). The degenerative changes in the PT group were more common in the medial and patellofemoral compartments ( P = .003 and P = .04, respectively).

CONCLUSION

Both autografts provided good to excellent subjective outcomes. No significant differences were noted in graft failure and clinical instability. However, significantly more patients in the STG group had increased instrumented anteroposterior translation measured with KT-1000 arthrometer, and there was a greater prevalence of knee OA at 17 years after surgery in the PT group.

The Timing of Rehabilitation Commencement After Reconstruction of the Anterior Cruciate Ligament

One of the most common injuries of the knee joint is a rupture of the anterior cruciate ligament (ACL). Most authors believe that early rehabilitation of patients after ACL reconstruction promotes better treatment outcomes. Less is known about the influence of the time that passes from injury to surgical reconstruction. Therefore, the goal of this study was to assess the dependence of treatment outcomes of ACL on injury-to-reconstruction and reconstruction-to-rehabilitation time lags. The study included 30 patients of the mean age 34 ± 7 years with trauma-related rupture of ACL and its surgical reconstruction. The time range from ligament rupture to its reconstruction was 120-180 days and from reconstruction to rehabilitation was 1-120 days. Postsurgical rehabilitation outcomes were assessed with the Lysholm knee scale and the IKDC 2000 subjective knee evaluation form. The scales were applied before and after rehabilitation. We found distinct improvements in all physical symptoms in the damaged knee joint, regardless of the time elapsed from trauma to ACL reconstruction and from ACL reconstruction to rehabilitation. The beneficial outcomes of rehabilitation were significantly inversely associated with the time elapsing from reconstruction to rehabilitation commencement but failed to depend on the time from ACL rupture to reconstruction. We conclude that rehabilitation should start as early as possible after ACL reconstruction to optimize the beneficial outcomes in terms of functional physical recovery, whereas the injury-to-reconstruction delay is less meaningful to this end.

A Method of Accurate Bone Tunnel Placement for Anterior Cruciate Ligament Reconstruction Based on 3-Dimensional Printing Technology: A Cadaveric Study

PURPOSE

To explore a method of bone tunnel placement for anterior cruciate ligament (ACL) reconstruction based on 3-dimensional (3D) printing technology and to assess its accuracy.

METHODS

Twenty human cadaveric knees were scanned by thin-layer computed tomography (CT). To obtain data on bones used to establish a knee joint model by computer software, customized bone anchors were installed before CT. The reference point was determined at the femoral and tibial footprint areas of the ACL. The site and direction of the bone tunnels of the femur and tibia were designed and calibrated on the knee joint model according to the reference point. The resin template was designed and printed by 3D printing. Placement of the bone tunnels was accomplished by use of templates, and the cadaveric knees were scanned again to compare the concordance of the internal opening of the bone tunnels and reference points.

RESULTS

The twenty 3D printing templates were designed and printed successfully. CT data analysis between the planned and actual drilled tunnel positions showed mean deviations of 0.57 mm (range, 0-1.5 mm; standard deviation, 0.42 mm) at the femur and 0.58 mm (range, 0-1.5 mm; standard deviation, 0.47 mm) at the tibia.

CONCLUSIONS

The accuracy of bone tunnel placement for ACL reconstruction in cadaveric adult knees based on 3D printing technology is high.

CLINICAL RELEVANCE

This method can improve the accuracy of bone tunnel placement for ACL reconstruction in clinical sports medicine.

Bench-to-bedside: Bridge-enhanced anterior cruciate ligament repair

Anterior cruciate ligament (ACL) injuries are one of the most well-known orthopaedic injuries and are treated with one of the most common orthopaedic procedures performed in the United States. This surgical procedure, ACL reconstruction, is successful at restoring the gross stability of the knee. However, the outcomes of ACL reconstruction can be limited by short and long-term complications, including muscle weakness, graft rupture, and premature osteoarthritis. Thus, new methods of treating this injury are being explored. This review details the pathway of how a tissue engineering strategy can be used to improve the healing of the ACL in preclinical studies and then translated to patients in an FDA-approved clinical study. This review paper will outline the clinical importance of ACL injuries, history of primary repair, the pathology behind failure of the ACL to heal, pre-clinical studies, the FDA approval process for a high risk medical device, and the preliminary results from a first-in-human study. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2606-2612, 2017.

Management of Anterior Cruciate Ligament Injury: What's In and What's Out?

Sports medicine physicians have a keen clinical and research interest in the anterior cruciate ligament (ACL). The biomechanical, biologic, and clinical data researchers generate, help drive injury management and prevention practices globally. The current concepts in ACL injury and surgery are being shaped by technological advances, expansion in basic science research, resurging interest in ACL preservation, and expanding efforts regarding injury prevention. As new methods are being developed in this field, the primary goal of safely improving patient outcomes will be a unifying principle. With this review, we provide an overview of topics currently in controversy or debate, and we identify paradigm shifts in the understanding, management, and prevention of ACL tears.