Current trends in the anterior cruciate ligament part II: evaluation, surgical technique, prevention, and rehabilitation

Early degenerative changes are different between partial and complete anterior cruciate ligament injury and associate with joint instability in a skeletally immature porcine model

OBJECTIVE

Anterior cruciate ligament (ACL) injuries are a major problem in the pediatric and adolescent populations. Some of these injuries are only partial; yet, there is limited data to inform clinical treatment of such partial tears. It is unknown how injury partial injury impacts long-term degenerative changes in the joint relative to complete injury. In this study, we hypothesized that partial (anteromedial (AM) or posterolateral (PL) bundle) tears would result in small levels of instability and degeneration relative to complete ACL tears and that the degree of degeneration would associate with joint instability.

DESIGN

Partial (isolated AM or PL bundle) or complete ACL injury was arthroscopically created in 3-month-old juvenile pigs. The contralateral limb served as a sham-operated control. Six months after injury, joint biomechanics was assessed along with cartilage and meniscus degeneration (via magnetic resonance imaging [MRI], gross imaging, and histology).

RESULTS

Joint laxity increases were minimal after PL bundle injury (difference relative to controls (confidence interval): 0.5 (-1.2-2.2) mm), minor after AM bundle injury (3.7 (2.0-5.4) mm), and major after ACL injury (15.8 (13.7-17.8) mm). Cartilage MRI T1ρ relaxation times increased minimally after PL bundle injury (-0.9 (-5.1-3.3) ms for lateral tibia), moderately after AM bundle injury (6.6 (1.7-11.4) ms), and substantially after ACL injury (10.8 (2.1-19.5) ms). Changes in meniscus volume followed a similar rank order. Degeneration was associated with the extent of joint destabilization.

CONCLUSIONS

These findings suggest that cartilage and meniscus degeneration in the skeletally immature joint are associated with joint laxity after partial and complete ACL injuries.

Risk factors for anteroposterior laxity increase over time in double-bundle anterior cruciate ligament reconstruction using hamstring autografts

PURPOSE

An anteroposterior (AP) laxity can increase over time after anterior cruciate ligament reconstruction (ACLR) using hamstring tendons; however, the associated risk factors remain unclear. This study aimed to investigate the risk factors of this phenomenon.

METHODS

Overall, 151 patients who underwent ACLR using hamstring autografts were recruited. AP laxity was evaluated using Knee Lax 3 arthrometer at 5 months, 1 and 2 years postsurgery. Patients were categorised into groups I (>1 mm increase) and C (<1 mm increase) based on whether they experienced an irreversible increase in AP laxity after 1 or 2 years compared with 5 months. Patient demographics and Knee injury and Osteoarthritis Outcome Score (KOOS) at 2 years postsurgery were compared between groups.

RESULTS

Group I (n = 33, 21%) showed a side-to-side difference of 4.6 (3.0-7.2) mm in AP laxity preoperatively and 0.3 (-0.7 to 1.3), 1.1 (0.2-1.9) and 2.4 (1.7-3.2) mm at 5 months, 1 and 2 years postoperatively, while group C (n = 119, 79%) showed 4.3 (2.8-5.7) mm preoperatively and 1.3 (0-1.9), 0.9 (0.1-1.8) and 0.6 (-0.3 to 1.5) mm, respectively. No significant differences were observed in the overall KOOS at 2 years (n.s.). However, group I was older (36 [22-46] vs. 28 [19-39] years; p = 0.044), had longer surgical waiting periods (122 [69-341] vs. 81 [52-136] days; p = 0.041) and lower preoperative Tegner activity scale scores (6 [5-7] vs. 7 [6,7]; p = 0.002).

CONCLUSION

While 33 patients (21%) experienced AP laxity increase over time, they had comparable clinical outcomes with group C.

LEVEL OF EVIDENCE

Level III.

Graft Selection in Anterior Cruciate Ligament Reconstruction: A Comprehensive Review of Current Trends

Anterior cruciate ligament (ACL) injuries are common in sports and often require surgical intervention, e.g., ACL reconstruction (ACLR), aimed at restoring knee stability and enabling a return to pre-injury activity levels. The choice of graft is crucial, impacting biomechanical properties, clinical outcomes, and complication rates, and is especially important in revision surgeries after graft failure. Over the past 30 years, trends in graft selection have evolved towards more individualized approaches, considering factors such as patient activity level, prior injuries, and tissue availability. In Europe, autografts like hamstring tendon (HT), bone-patellar tendon-bone (BTB), and quadriceps tendon (QT) are preferred, with the increasing use of QT grafts. This review synthesizes the current literature on graft selection and its influence on ACLR outcomes.

Anterior Cruciate Ligament Reconstruction Basics: Quadriceps Tendon (All-Soft Tissue) Autograft Preparation-Part 2

Anterior cruciate ligament reconstruction with quadriceps tendon autograft is a reliable graft option that has recently increased in use. Varying harvesting and graft preparation techniques available and improved technology and implant design continue to make quadricep tendon preparation more efficient and reproducible. In this Technical Note, we describe our preferred technique for all-soft tissue quadriceps tendon autograft preparation after harvest for anterior cruciate ligament reconstruction.

Never Assume Successful Treatment of Septic Arthritis: Bacteria Isolated at Revision ACL Reconstruction 3 Years After Primary ACL Reconstruction "Successfully" Treated for Infection

LEVEL OF EVIDENCE

Level IV.

Commitment of human mesenchymal stromal cells towards ACL fibroblast differentiation upon rAAV-mediated FGF-2 and TGF-β overexpression using pNaSS-grafted PCL films

Despite various clinical options, human anterior cruciate ligament (ACL) lesions do not fully heal. Biomaterial-guided gene therapy using recombinant adeno-associated virus (rAAV) vectors may improve the intrinsic mechanisms of ACL repair. Here, we examined whether poly(sodium styrene sulfonate)-grafted poly(ε-caprolactone) (pNaSS-grafted PCL) films can deliver rAAV vectors coding for the reparative basic fibroblast growth factor (FGF-2) and transforming growth factor beta (TGF-β) in human mesenchymal stromal cells (hMSCs) as a source of implantable cells in ACL lesions. Efficient and sustained rAAV-mediated reporter (red fluorescent protein) and therapeutic (FGF-2 and TGF-β) gene overexpression was achieved in the cells for at least 21 days in particular with pNaSS-grafted PCL films relative to all other conditions (up to 5.2-fold difference). Expression of FGF-2 and TGF-β mediated by rAAV using PCL films increased the levels of cell proliferation, the DNA contents, and the deposition of proteoglycans and of type-I and -III collagen (up to 2.9-fold difference) over time in the cells with higher levels of transcription factor expression (Mohawk, Scleraxis) (up to 1.9-fold difference), without activation of inflammatory tumor necrosis alpha especially when using pNaSS-grafted PCL films compared with the controls. Overall, the effects mediated by TGF-β were higher than those promoted by FGF-2, possibly due to higher levels of gene expression achieved upon rAAV gene transfer. This study shows the potential of using functionalized PCL films to apply rAAV vectors for ACL repair.

Trends in Anterior Cruciate Ligament Reconstruction Techniques and Postoperative Care Among Leaders in the Field: A Survey of the Herodicus Society

Background

Despite a growing body of literature regarding anterior cruciate ligament reconstruction (ACLR), there remains a wide diversity in surgical technique and clinical practice across providers.

Purpose

To (1) describe current ACLR practice preferences among members of the Herodicus society and (2) determine whether these preferences are influenced by years in practice and overall surgical volume.

Study Design

Cross-sectional study.

Methods

A 24-question survey investigating surgeons' practices and preferred ACLR surgical techniques was sent via email to all active Herodicus Society members. Survey responses were subdivided by years of experience and overall ACLR annual case volume. Descriptive statistics were compiled and chi-square testing was utilized to determine the significance of experience and case volume on survey responses.

Results

Of the 113 invited Herodicus Society members who perform ACLR, 69 (61%) completed the survey. Respondents had a mean ± SD of 30.9 ± 9.8 years of experience in clinical practice and performed a mean of 96.0 ± 50.7 primary and 21.6 ± 16.9 revision ACLR annually. Of revision cases, 72.1% were performed using a single-stage technique. Mean frequency of graft usage by surgeon was bone-patellar tendon-bone autograft (58.6%), quadriceps autograft (14.6%), hamstring tendon autograft (14.0%), and allograft (11.8%). The plurality of surgeons responded that they used anterolateral augmentation "rarely" in primary ACLR (39.1%) and "sometimes" in revision ACLR (31.9%), with the majority performing lateral extra-articular tenodesis (66.7%) rather than anterolateral ligament reconstruction (14.5%). Most surgeons would not allow a 20-year-old football player to return before 7 months after ACLR (71.0%) but highly valued return-to-sports testing to determine readiness (94.2%). Higher volume surgeons performed single-stage revision ACLR at a significantly higher rate (79.8% vs 62.9%, P = .02) and significantly differed in return-to-sports criteria, with a greater proportion relying primarily on biometric testing (P = .01).

Conclusion

The survey demonstrated that, in the Herodicus Society, a wide range of preferences exist regarding ACLR surgical technique. Bone-patellar tendon-bone autograft is the most frequent primary ACLR graft choice. Most participants have not embraced newer techniques such as anterolateral or suture tape augmentation. Return to sports is generally not allowed before 7 months and heavily factors-in return-to-sports testing metrics, suggesting that purely time-based criteria for return to sports is not modern practice among elite sports medicine surgeons.

Virtual reality-based therapy after anterior cruciate ligament injury effectively reduces pain and improves knee function, movement patterns, and dynamic balance: A systematic review and meta-analysis

PURPOSE

Virtual reality-based therapy (VRBT) may be an effective physical therapy complement employed in the rehabilitation of patients with anterior cruciate ligament (ACL) injury. This study aims to assess the effectiveness of VRBT in improving pain, knee function, strength, proprioception, flexion range of motion (ROM), and dynamic balance after ACL injury.

METHODS

We conducted this systematic review with meta-analysis following PRISMA criteria. Since inception to June 2024, we searched in PubMed Medline, WOS, SCOPUS, CINAHL and PEDro without publication date and language restrictions. Randomised controlled trials (RCTs), comprising only patients with ACL injury, that assess the effectiveness of VRBT compared to classical interventions on the outcomes of interest were included. PEDro scale was employed to analyze the methodological quality of the RCTs included. Cohen's standardised mean difference (SMD) and its 95% confidence interval (95% CI) was used to calculate the pooled effect in meta-analyses.

RESULTS

Nine RCTs, providing data from 330 participants (26.96 ± 3.11 years, 85% males) were included. The RCTs included showed good methodological quality (PEDro scale = 6.88 points), being, performance and detection biases, the most common biases reported. Meta-analyses showed that VRBT was more effective than classical interventions in reducing pain (SMD = -1.15; 95% CI -1.85 to -0.45; p = 0.001; I2 = 0%), and increasing knee function (SMD = 1.71; 95% CI 0.93 to 2.5; p < 0.001; I2 = 0%), strength (SMD = 0.82; 95% CI 0.4-1.23; p < 0.001; I2 = 0%) and flexion ROM (SMD = 0.7; 95% CI 0.37-1.01; p < 0.001; I2 = 0%). Additionally, VRBT improved postero-medial (SMD = 0.46; 95% CI 0.01-0.9; p = 0.045; I2 = 15.1%) and postero-lateral CoP excursion (SMD = 0.75; 95% CI 0.3-1.21; p = 0.001; I2 = 0%), being effective in improving dynamic balance.

CONCLUSION

VRBT is an effective physical therapy complement to be included in the ACL's rehabilitation programmes due to reduces pain and increases knee function, strength, ROM and dynamic balance after ACL injury.

LEVEL OF EVIDENCE

Level II evidence.

One type of graft for reconstruction of the ACL does not suit all patients based on their characteristics and sports: a scoping review

The selection of graft type for anterior cruciate ligament reconstruction remains a topic of debate, taking into consideration patient characteristics, as well as the type and level of sports involvement. The aim of this scoping review was to investigate patient characteristics that might influence the selection of graft type for anterior cruciate ligament reconstruction. PubMed and Scopus were searched to identify articles for inclusion. All included studies focused on one or more patient characteristics involved in the decision-making process regarding anterior cruciate ligament reconstruction autograft, including the hamstrings tendon (HT), patellar tendon (BPTB) and quadriceps tendon (QT). Out of the 1,977 initial studies, 27 studies were included in this review. The BPTB graft seems to be the preferred choice in young patients, females, and athletes-especially those engaged in pivoting sports. The HT graft seems to be the preferred choice in less active and older patients, along with those involved in sports where knee extensors are vital. The HT graft is not preferable in patients with a small body height and graft diameter. Moreover, surgeon preferences were also of importance for graft selection. The success of a specific graft type in anterior cruciate ligament reconstruction is highly dependent on the patient's characteristics and type of sport. Patient characteristics such as age, gender, body height, graft diameter, and the patient's activity level should all be considered when choosing the appropriate graft type.

Mesenchymal stem cell-derived extracellular vesicles in joint diseases: Therapeutic effects and underlying mechanisms

Joint diseases greatly impact the daily lives and occupational functioning of patients globally. However, conventional treatments for joint diseases have several limitations, such as unsatisfatory efficacy and side effects, necessitating the exploration of more efficacious therapeutic strategies. Mesenchymal stem cell (MSC)-derived EVs (MSC-EVs) have demonstrated high therapeutic efficacyin tissue repair and regeneration, with low immunogenicity and tumorigenicity. Recent studies have reported that EVs-based therapy has considerable therapeutic effects against joint diseases, including osteoarthritis, tendon and ligament injuries, femoral head osteonecrosis, and rheumatoid arthritis. Herein, we review the therapeutic potential of various types of MSC-EVs in the aforementioned joint diseases, summarise the mechanisms underlying specific biological effects of MSC-EVs, and discuss future prospects for basic research on MSC-EV-based therapeutic modalities and their clinical translation. In general, this review provides an in-depth understanding of the therapeutic effects of MSC-EVs in joint diseases, as well as the underlying mechanisms, which may be beneficial to the clinical translation of MSC-EV-based treatment. The translational potential of this article: MSC-EV-based cell-free therapy can effectively promote regeneration and tissue repair. When used to treat joint diseases, MSC-EVs have demonstrated desirable therapeutic effects in preclinical research. This review may supplement further research on MSC-EV-based treatment of joint diseases and its clinical translation.

Transtibial versus anteromedial transportal femoral tunnel in single-bundle anterior cruciate ligament reconstruction: a systematic review and meta-analysis of prospective randomized controlled trials

The purpose of this study was to systematically review and meta-analyze randomized controlled trials (RCTs) reporting the comparative clinical and functional outcomes, postoperative complications, and radiological outcomes of single-bundle anterior cruciate ligament reconstruction (ACLR) performed using the transtibial (TT) approach or anteromedial (AM) technique. A systematic review of the literature was performed according to Cochrane and PRISMA guidelines. RCTs comparing TT and AM techniques were considered only. The quality of the studies was defined using the GRADE system, and the risk of bias was assessed with the RoB 2 tool. The primary endpoint was to systematically review and meta-analyze the clinical outcomes, residual laxity and failure rate of both AM and TT techniques. In the current meta-analysis 13 RCTs involving 989 patients who underwent arthroscopic single-bundle ACLR (486 TT and 503 AM) were included. Patients undergoing AM technique resulted in higher objective-IKDC (p < 0.001) and Lysholm scores (p = 0.002), despite a lower incidence of pathological anterior tibial translation (p < 0.001) and positive pivot-shift test (p < 0.001). No differences were detected in IKDC subjective score (p = 0.26), Tegner activity scale (p = 0.18) and graft failure (p = 0.07). ACL reconstruction through AM portal technique provides better clinical outcomes and lower incidence of residual rotational and anteroposterior laxity in comparison with the TT technique. No statistically significant difference in subjective outcomes and graft failure was reported.

A Single-Surgeon 35-Year Experience With ACL Reconstruction Using Patellar Tendon Auto- and Allografts With the Transtibial Technique

Background

Long-term follow-up for anterior cruciate ligament reconstruction (ACLR) is limited due to heterogeneity in the number of techniques utilized, the number of surgeons included, and attrition bias.

Purpose

To analyze a single surgeon's 35-year experience with ACLR using the transtibial technique, with an emphasis on temporal trends in graft selection and subanalyses on rates of revision surgery, contralateral ACLR, and nonrevision reoperation among different demographic cohorts of patients.

Study Design

Case series; Level of evidence, 4.

Methods

All patients who underwent arthroscopically assisted single-bundle ACLR between 1986 and 2021 were identified from a prospectively maintained single-surgeon registry. Outcomes of interest included revision, reoperation, and contralateral rupture rates.

Results

A total of 2915 ACLRs were performed during the senior surgeon's career. The mean age for primary ACLR was 29.4 ± 14.8 years. During primary ACLR, 98.4% of patients received a central-third bone-patellar tendon-bone (BPTB) graft. Increasing patient age was associated with increasing allograft usage (P < .01), with a significant temporal increase in allograft usage over the senior surgeon's career (P < .01). There was a higher revision rate among younger patients (P < .01), female patients aged 21 to 25 years (P = .01), and patients who received an allograft during the primary procedure (P = .04). The contralateral rupture rate showed no difference between sexes (P = .34); however, patients who underwent ACLR with autograft had a greater rate of contralateral injury compared with those with allograft (P < .01). The contralateral rupture rate was greater than the revision rate (P < .01). The most common causes of nonrevision reoperation were failed meniscal repair, new meniscal tears, arthrofibrosis, and painful hardware removal.

Conclusion

The findings of this single-surgeon registry reveal temporal trends in ACLR over a 35-year career. There was a trend toward increasing BPTB allograft use in ACLR, especially in older patients and revision cases. A greater revision rate was observed among younger patients, female patients, and those receiving allografts during primary surgery. Contralateral ACLR was more common than revision surgery.

Patellar bone defect grafting does not reduce anterior knee pain after bone-patellar tendon-bone anterior cruciate ligament reconstruction

PURPOSE

Donor site morbidity is the main drawback to using bone-patellar tendon-bone (BPTB) as a graft in anterior cruciate ligament (ACL) reconstruction. The objective of the study was to determine whether refilling the patellar bone defect after BPTB harvesting with autograft bone decreased kneeling pain to a greater degree when compared with a group in which bone defect is left unaddressed.

METHODS

This is a randomised single-blinded controlled study. Forty patients were randomised into two groups; group 1: Patellar bone defect filled with autologous bone; group 2: Bone defect left undressed. Pain was measured by means of pressure algometry (PA). Functional outcomes were measured with the Kujala and Victorian Institute of Sport Assessment-Patella (VISA-P) score. Magnetic resonance imaging (MRI) was done to measure bone buildup between groups at the 1-year follow-up.

RESULTS

No differences were observed in the different algometry measurements and the scores were assessed at 3, 6 and 12 months postoperatively. The ratio of void filled remained consistently higher (p = 0.003) in group 1 when compared to group 2.

CONCLUSIONS

Although refilling the lower pole of the patella with autologous bone from the harvested BPTB autograft loads the bone defect, it does not reduce pain at the donor site 1 year after surgery.

LEVEL OF EVIDENCE

Therapeutic study level 1.

Analysis of Gait Kinematics in Smart Walker-Assisted Locomotion in Immersive Virtual Reality Scenario

The decline in neuromusculoskeletal capabilities of older adults can affect motor control, independence, and locomotion. Because the elderly population is increasing worldwide, assisting independent mobility and improving rehabilitation therapies has become a priority. The combination of rehabilitation robotic devices and virtual reality (VR) tools can be used in gait training to improve clinical outcomes, motivation, and treatment adherence. Nevertheless, VR tools may be associated with cybersickness and changes in gait kinematics. This paper analyzes the gait parameters of fourteen elderly participants across three experimental tasks: free walking (FW), smart walker-assisted gait (AW), and smart walker-assisted gait combined with VR assistance (VRAW). The kinematic parameters of both lower limbs were captured by a 3D wearable motion capture system. This research aims at assessing the kinematic adaptations when using a smart walker and how the integration between this robotic device and the VR tool can influence such adaptations. Additionally, cybersickness symptoms were investigated using a questionnaire for virtual rehabilitation systems after the VRAW task. The experimental data indicate significant differences between FW and both AW and VRAW. Specifically, there was an overall reduction in sagittal motion of 16%, 25%, and 38% in the hip, knee, and ankle, respectively, for both AW and VRAW compared to FW. However, no significant differences between the AW and VRAW kinematic parameters and no adverse symptoms related to VR were identified. These results indicate that VR technology can be used in walker-assisted gait rehabilitation without compromising kinematic performance and presenting potential benefits related to motivation and treatment adherence.

ACL reconstruction combined with anterolateral structures reconstruction for treating ACL rupture and knee injuries: a finite element analysis

Introduction: The biomechanical indication for combining anterolateral structures reconstruction (ASLR) with ACL reconstruction (ACLR) to reduce pivot shift in the knee remains unclear. This study aims to investigate knee functionality after ACL rupture with different combinations of injuries, and to compare the effectiveness of ALSR with ACLR for treating these injuries. Methods: A validated finite element model of a human cadaveric knee was used to simulate pivot shift tests on the joint in different states, including 1) an intact knee; 2) after isolated ACL rupture; 3) after ACL rupture combined with different knee injuries or defect, including a posterior tibial slope (PTS) of 20°, an injury to the anterolateral structures (ALS) and an injury to the posterior meniscotibial ligament of the lateral meniscus (LP); 4) after treating the different injuries using isolated ACLR; v. after treating the different injuries using ACLR with ALSR. The knee kinematics, maximum von Mises stress (Max.S) on the tibial articular cartilage (TC) and force in the ACL graft were compared among the different simulation groups. Results and discussion: Comparing with isolated ACL rupture, combined injury to the ALS caused the largest knee laxity, when a combined PTS of 20° induced the largest Max.S on the TC. The joint stability and Max.S on the TC in the knee with an isolated ACL rupture or a combined rupture of ACL and LP were restored to the intact level after being treated with isolated ACLR. The knee biomechanics after a combined rupture of ACL and ALS were restored to the intact level only when being treated with a combination of ACLR and ALSR using a large graft diameter (6 mm) for ALSR. However, for the knee after ACL rupture combined with a PTS of 20°, the ATT and Max.S on the TC were still greater than the intact knee even after being treated with a combination of ACLR and ALSR. The finite element analysis showed that ACLR should include ALSR when treating ACL ruptures accompanied by ALS rupture. However, pivot shift in knees with a PTS of 20° was not eliminated even after a combined ACLR and ALSR.

Serial Assessment of Factors Associated With Patient-Reported Outcomes up to 2 Years After ACL Reconstruction Using Autologous Hamstring Tendon: Results From the TMDU MAKS Study

Background

Understanding the factors related to patient-reported outcomes (PROs) after anterior cruciate ligament reconstruction (ACLR) can lead to more effective interventions.

Purpose/Hypothesis

The purpose of this study was to identify factors associated with PRO scores after ACLR. It was hypothesized that concomitant meniscal treatment and postoperative range of motion (ROM) would be associated with early postoperative PRO scores and that postoperative physical findings would be associated with 2-year postoperative PRO scores.

Study Design

Cohort study; Level of evidence, 2.

Methods

We examined the data from the Tokyo Medical and Dental University Multicenter Arthroscopic Knee Surgery (TMDU MAKS) Study for patients who underwent primary ACLR with autologous hamstring tendon grafts; 1252 patients in the TMDU MAKS Study were eligible for inclusion. The International Knee Documentation Committee (IKDC) subjective score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Lysholm score of the patients at 3 months (n = 675), 1 year (n = 660), and 2 years (n = 375) postoperatively were assessed using multiple regression to evaluate the strength of the relationship between PRO scores and the following predictor variables: patient-specific factors, treatment-specific factors, and physical findings.

Results

Improvement in all PROs significantly exceeded the minimal important change at 1 and 2 years postoperatively. Older age and female sex were predictive of lower PRO scores up to 2 years postoperatively. Concurrent meniscal treatment and limited range of knee motion were predictive of lower PRO scores at 3 months and 1 year postoperatively. A tighter knee (ie, less anterior translation) on the injured side compared with the contralateral knee was predictive of lower KOOS-Quality of Life and IKDC scores at 2 years postoperatively. At all 3 postoperative time points, greater side-to-side difference in knee ROM was predictive of lower PRO scores.

Conclusion

Inferior PRO scores were associated with concomitant meniscal treatment and limited postoperative ROM until 1 year postoperatively and with older age and female sex up to 2 years postoperatively. PRO scores were associated with knee stability at all assessed time points.

Lateral femoral tunnel preparation and graft fixation for anterior cruciate ligament reconstruction-A discussion

This article provides a discussion and commentary around the recent advances in arthroscopic anterior cruciate ligament reconstruction (ACLR), with a focus on the aspects of lateral femoral tunnel preparation and graft fixation techniques. The paper explores and comments on a recently published review by Dai et al, titled "Research progress on preparation of lateral femoral tunnel and graft fixation in ACLR", while providing insight into its relevance within the field of ACLR, and recommendations for future research.

Revision ACL reconstruction in female athletes: current concepts

The challenge of revision anterior cruciate ligament (ACL) reconstruction lies in its complexity, varied presentation, and technical intricacies. A successful ACL reconstruction should allow patients to safely return to preinjury activities. However, it is only sometimes simple, and many risk factors and concurrent pathologies come into play. Evaluating and analysing the cause of failure and associated conditions is paramount to addressing them effectively. Despite a plethora of research and improvements in knowledge and technology, e gaps exist in issues such as optimal techniques of revision surgery, graft options, fixation, concurrent procedures, rehabilitation and protocol for return to sports of high-level athletes. Female athletes need additional focus since they are at higher risk of re-injury, suboptimal clinical outcomes, and lower rates of return to sport following revision reconstruction. Our understanding about injury prevention and the protection of ACL grafts in female athletes needs to be improved. This review focuses on the current state of revision ACL surgery in female athletes and provides recommendations and future directions for optimising outcomes in this high-risk group.

Good clinical outcomes of anterior cruciate ligament reconstruction in patients over 60 years of age

PURPOSE

To evaluate the clinical outcomes following arthroscopic anterior cruciate ligament (ACL) reconstruction (ACLR) in patients over 60 years and to investigate the potential impact of preoperative osteoarthritis (OA) on these outcomes.

METHODS

A retrospective study included ACL-injured patients over 60 years who underwent primary arthroscopic ACLR between 2010 and 2020. The Lysholm score and the International Knee Documentation Committee (IKDC) score were assessed preoperatively and at the final follow-up. The Tegner activity scale was performed to evaluate patients' activity levels. Data on return to sports, patient satisfaction, subsequent injuries and complications were collected. Preoperative radiographs were used to grade OA according to the Kellgrene-Lawrence classification. Correlation analysis between OA and clinical outcomes was performed. The rates of achieving the minimal clinically significant difference and patient-acceptable symptoms state were documented.

RESULTS

A total of 37 patients were included in this study. The mean age at surgery was 62.3 ± 2.3 years, with a mean follow-up of 6.3 ± 3.2 years (range: 2.1-12.4). Patients showed statistically significant (all p < 0.001) improvements in the mean IKDC (38.9 ± 9.4-66.8 ± 12.5), Lysholm (48.8 ± 15.4-83.0 ± 12.8) and Tegner (1-3) scores. Fourteen patients (37.8%) returned to sports. No correlation was observed between the degree of preoperative OA and clinical outcomes (n.s.).

CONCLUSION

Patients over 60 years with symptomatic ACL-deficient knees could benefit from ACLR, even when mild to moderate OA is present preoperatively.

LEVEL OF EVIDENCE

Level IV.

The Addition of the Gracilis Tendon to a Semitendinosus Tendon Autograft Is Not Associated With Knee Muscle Strength, Subjective Knee Function, or Revision Surgery After Anterior Cruciate Ligament Reconstruction

PURPOSE

To evaluate and compare isokinetic knee muscle (extension and flexion) strength, single-leg hop (SLH) test performance, anterior knee laxity, subjective knee function, and the 2-year revision surgery risk between patients who underwent anterior cruciate ligament reconstruction (ACLR) with semitendinosus tendon (ST) autografts and patients who underwent ACLR with ST and gracilis tendon (ST-G) autografts.

METHODS

We identified patients aged 16 years or older who underwent primary ACLR with hamstring tendon autografts at our institution from January 2005 to December 2020 and had no associated ligament injuries. Isokinetic knee muscle strength and SLH test performance were assessed 6 months postoperatively. Anterior knee laxity (KT-1000 arthrometer, 134 N) was assessed preoperatively and 6 months postoperatively. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and 1 and 2 years postoperatively. Patients who underwent revision ACLR at any institution in Sweden within 2 years of primary surgery were identified through the Swedish National Knee Ligament Registry.

RESULTS

A total of 6,974 patients (5,479 with ST and 1,495 with ST-G) were included. There were no significant differences in extension and flexion strength or SLH test performance between the groups. Preoperatively, there was no significant difference in knee laxity between the ST and ST-G groups. Postoperatively, the ST-G group had significantly increased mean side-to-side (STS) laxity (2.1 ± 2.3 mm vs 1.7 ± 2.2 mm, P < .001) and showed a trend toward increased STS laxity according to the International Knee Documentation Committee form, with significantly fewer patients with STS laxity of 2 mm or less (58.4% vs 65.8%) and significantly more patients with STS laxity between 3 and 5 mm (35.0% vs 29.9%) or greater than 5 mm (6.6% vs 4.3%) (P < .001). The only significant difference in subjective knee function was for the KOOS Quality of Life subscale score in favor of the ST group preoperatively (37.3 ± 21.4 vs 35.1 ± 19.9, P = .001). No other significant differences between the groups were found preoperatively and 1 and 2 years postoperatively for any of the KOOS subscales. The overall revision ACLR rate within 2 years of primary surgery was 2.0% (138 of 6,974 patients). The revision ACLR risk in the ST-G group (1.7%, 25 of 1,495 patients) was not significantly different from that in the ST group (2.1%, 113 of 5,479 patients) (hazard ratio, 0.80; 95% confidence interval, 0.50-1.24; P = .32).

CONCLUSIONS

The addition of the gracilis tendon to an ST autograft was not associated with knee muscle strength, SLH test performance, subjective knee function, or the risk of revision surgery after ACLR.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Femoral Fixation Strength as a Function of Bone Plug Length in Anterior Cruciate Ligament Reconstruction Utilizing Interference Screws

PURPOSE

 To determine femoral construct fixation strength as bone plug length decreases in anterior cruciate ligament reconstruction (ACLR).

METHODS

 Sixty fresh-frozen bone-patellar tendon-bone allografts were utilized and divided into 20-, 15-, and 10-mm length bone plug groups, subdivided further so that half utilized the patella side (P) for testing and half used the tibial side (T). Ten mm diameter recipient tunnels were created within the anatomic anterior cruciate ligament footprint of 60 cadaveric femurs. All bone plugs were 10 mm in diameter; grafts were fixed using a 7 × 23 mm metal interference screw. An Instron was used to determine the load to failure of each group. A one-way multivariate analysis of variance (MANOVA) was conducted to test the hypothesis that there would be one or more mean differences in fixation stability between 20- or 15-mm plug lengths (P or T) versus 10 mm T plug lengths when cross-compared, with no association between other P or T subgroups.

RESULTS

 The mean load to failure of the 20 mm plugs (20 P + T) was 457 ± 66N, 15 mm plugs (15 P + T) was 437 ± 74N, and 10 mm plugs (10 P + T) was 407 ± 107N. There was no significant difference between P + T groups: 20-versus 15-mm (p = 1.000), 15-versus 10-mm (p = 0.798), and 20-versus 10-mm (p = 0.200); P + T MANOVA (p = 0.291). Within groups, there was no significant difference between patella and tibial bone plug subgroups with a pullout force range between 469 ± 56N and 374 ± 116N and p-value ranging from p = 1.000 for longer bone plugs to p = 0.194 for shorter bone plugs; P versus T MANOVA (p = 0.113).

CONCLUSION

 In this human time zero cadaver model, there was no significant difference in construct failure between 20-,15-, and 10-mm bone plugs when fixed with an interference screw within the femoral tunnel, although fixation strength did trend down when from 20- to 15- to 10-mm bone plugs.

CLINICAL RELEVANCE

 There is a balance between optimal bone plug length on the femoral side for achieving adequate fixation as well as minimizing donor site morbidity and facilitating graft passage in ACLR. This study reveals utilizing shorter plugs with interference screw fixation is potentially acceptable on the femoral side if shorter plugs are harvested.

Information videos posted on Instagram by orthopaedics and sports traumatology surgeons mostly explain surgical technique, and the least mentioned topics are injury prevention and complications

PURPOSE

Social media has become the new information acquisition platform for all content producers. In the current literature, there are no studies examining the content quality and the strengths and weaknesses of videos on Instagram that explain anterior cruciate ligament (ACL) injuries, which is the most discussed topic of sports surgery. The aim of this study was to evaluate the quality, strengths and weaknesses of information pertaining to ACL surgery that is disseminated on Instagram.

METHOD

An Instagram search was conducted from 30 May 2023 to 30 January 2024. The search encompassed six languages (English, Spanish, German, French, Italian and Turkish) and was performed by six different observers. The investigation focused on eight subheadings derived from current literature on the ACL. These subheadings were addressed in Instagram videos, covering ACL biology or biomechanics, injury mechanism, injury prevention, injury evaluation, surgical technique, injury or surgery complications, injury rehabilitation process and return to sport or work.

RESULT

The content was assessed of 127 videos from 127 Instagram accounts, spanning six different languages. Across the review of eight subheadings, the average number covered for the entire group was 3 (range, 0-8). Further analysis revealed that surgical technique was the most frequently mentioned subheading for the whole group (68.5%), followed by injury evaluation (54.3%). Prevention (10.2%) and complications (19.6%) were the least mentioned subheadings. The number of followers showed a correlation with video content quality.

CONCLUSION

Although the video quality scores were found to be moderate, the content often focused on surgery and evaluation subheadings. The prevalence of incomplete information underscores the importance of developing strategies to ensure more comprehensive and accurate dissemination of medical knowledge.

LEVEL OF EVIDENCE

Level V.

Association of Graft Maturity on MRI With Return to Sports at 9 Months After Primary Single-Bundle ACL Reconstruction With Autologous Hamstring Graft

Background

The relationship between graft maturity on magnetic resonance imaging (MRI) and return to sports (RTS) after anterior cruciate ligament (ACL) reconstruction is unclear.

Purpose

To compare signal-to-noise quotient (SNQ) values and ACL graft T2* (gradient echo) values between patients who did RTS and those who did not RTS (NRTS) after ACL reconstruction and to evaluate the predictive value of T2* mapping for RTS after ACL reconstruction.

Study Design

Case-control study; Level of evidence, 3.

Methods

At a minimum of 9 months after arthroscopic single-bundle ACL reconstruction with autologous hamstring tendon graft, 82 patients underwent RTS assessment as well as MRI evaluation. The patients were classified into RTS (n = 53) and NRTS (n = 29) groups based on the results of the assessment. The SNQ values in the proximal, middle, and distal regions of the graft and the T2* values of the graft were measured on MRI. The correlation between T2* values and RTS was assessed using Spearman correlation analysis. Receiver operating characteristic curves were constructed to compare the diagnostic performance, and the optimal T2* cutoff value for detecting RTS was determined based on the maximum Youden index.

Results

At 9 months after ACL reconstruction, the proximal, middle, and mean SNQ values in the RTS group were significantly lower than those in the NRTS group (proximal: 17.15 ± 4.85 vs 19.55 ± 5.05, P = .038; middle: 13.45 ± 5.15 vs. 17.75 ± 5.75, P = .001; mean: 12.37 ± 2.74 vs 15.07 ± 3.32, P < .001). The T2* values were lower in the RTS group (14.92 ± 2.28 vs 17.69 ± 2.48; P < .001) and were correlated with RTS (r = -0.41; P = .02). The area under the curve of T2* was 0.79 (95% CI, 0.75-0.83), and the optimal cutoff value for T2* was 16.65, with a sensitivity and specificity for predicting failure to RTS of 67.9% and 88.2%, respectively.

Conclusion

Study findings indicated that the SNQs (mean, proximal, and middle) and the T2* values of the graft in the RTS group were significantly lower than those in NRTS group. A T2* value of 16.65 was calculated to predict patients who failed RTS tests with a sensitivity of 67.9% and specificity of 88.2%.

Current views on preoperative rehabilitation practice after anterior cruciate ligament injury among licensed physical therapists in Saudi Arabia: An online-based cross-sectional survey

Preoperative rehabilitation is an important stage to both physically and mentally prepare patients for anterior cruciate ligament reconstruction (ACLR) and postoperative rehabilitation. This study aimed to investigate the current preoperative rehabilitation practice after anterior cruciate ligament injury among licensed physical therapists in Saudi Arabia. This was an online-based cross-sectional survey. A total of 114 physical therapists completed the survey. The survey consisted of 16 mandatory questions about management strategies, prescribed exercises, patients' physical and psychological concerns, and discussions about nonoperative management. The majority of the respondents used the following preoperative interventions: education (89.5%), closed kinetic chain exercises (66.7%), stretches (63.2%), open kinetic chain exercises (61.4%), proprioceptive exercises (59.6%), cold (56.1%), and activity modification advice (52.6%). More than half of the respondents would recommend patients awaiting ACLR to complete the exercises 2 to 4 times weekly (56.1%) for up to 8 weeks (80.7%) before ACLR. The respondents (73.7%) reported that patients awaiting ACLR did not receive preoperative rehabilitation due to 2 primary factors: the orthopedic team did not refer patients to rehabilitation specialists, and there was a lack of awareness about preoperative rehabilitation. Most therapists (86%) would discuss conservative management if a patient returned to their preinjury level of function before surgery. The surveyed physical therapists reported using various interventions and preoperative rehabilitation lengths with patients awaiting ACLR. The majority of the therapists indicated that patients awaiting ACLR did not receive preoperative rehabilitation. Future studies are needed to establish a consensus on the optimal preoperative rehabilitation program.

ACL Volume Measurement Using a Multi-truncated Pyramid Shape Simulation

Purpose

The purpose of this study was to measure anterior cruciate ligament (ACL) volume in a newly reported multi-truncated pyramid shape simulation using axial magnetic resonance imaging (MRI) for the detailed knowledge of the ACL anatomy.

Methods

Fifty subjects (27 female and 23 male, average age: 23 ± 7.8) visiting our clinic with knee pain and in whom MRI showed no structural injury were included in this study. Using the axial image of the MRI, four deferent levels of the cross-sectional area of the ACL were measured. ACL height was measured as the distance between the most proximal and distal slices of the MRI. ACL volume was calculated using a multi-truncated pyramid shape simulation. Femoral intercondylar notch height, area, and trans-epicondylar length (TEL) were also measured using MRI.

Results

The measured top, proximal 1/3, distal 1/3, and bottom of the ACL cross-sectional area were, 36.8 ± 10.7, 59.9 ± 15.4, 66.4 ± 20.8, and 107.3 ± 21.1mm2, respectively. ACL height was 26.3 ± 3.9 mm. Using these data, the calculated ACL volume was 1755 ± 874mm3. Significant correlations were observed between ACL volume and notch height, area, and TEL.

Conclusion

Similar ACL volume with previous reports was obtained in this simple and easy multi-truncated pyramid shape simulation from axial MRI evaluation. Significant correlation was observed between ACL volume and knee bony morphology. The ability of surgeons to measure ACL volume simply and effectively can be useful for the detailed ACL anatomical knowledge, and also for prediction and prevention of ACL injury.Level of evidence: IV, Case series.

The apex of the deep cartilage is a stable landmark to position the femoral tunnel during remnant-preserving anterior cruciate ligament reconstruction

PURPOSE

The aim of this retrospective cohort study was to investigate whether the apex of the deep cartilage (ADC) could help surgeons position the femoral tunnel accurately in remnant-preserving anterior cruciate ligament (ACL) reconstruction (ACLR).

METHODS

In the current retrospective cohort study, a total of 134 patients who underwent ACLR between 2016 and 2020 were included. The femoral tunnel position was located using ADC as the landmark. The patients were divided into two groups: the remnant-preserving group (RP group, n = 68) underwent remnant-preserving ACLR, and the nonremnant group (NRP group, n = 66) underwent traditional ACLR with remnant removal. Postoperatively, the femoral tunnel position was evaluated on 3D-CT. The length from the ADC to the shallow cartilage margin (L) and to the centre of the femoral tunnel (l) and the length from the centre of the femoral tunnel to a low cartilage ratio in the direction from high to low (H) were measured.

RESULTS

The l/L values of the RP and NRP groups were both 0.4 ± 0.1 after rounding (n.s.), and the H values were 9.3 ± 1.6 mm and 9.3 ± 1.7 mm, respectively (n.s.). There was no significant difference in l/L or H between the two groups. The estimation plot also showed high consistency of H and l/L of the two groups. The inter- and intraobserver reliability of I, L, l/L, and H were almost perfect.

CONCLUSIONS

The apex of the deep cartilage is a good landmark for positioning the femoral tunnel in remnant-preserving ACL reconstruction.

LEVEL OF EVIDENCE

Level III.

The "Bankart knee": high-grade impression fractures of the posterolateral tibial plateau lead to increased translational and anterolateral rotational instability of the ACL-deficient knee

PURPOSE

The aim of this biomechanical cadaver study was to evaluate the effects of high-grade posterolateral tibia plateau fractures on the kinematics of anterior cruciate ligament (ACL)-deficient joints; it was hypothesized that, owing to the loss of the integrity of the osseous support of the posterior horn of the lateral meniscus (PHLM), these fractures would influence the biomechanical function of the lateral meniscus (LM) and consequently lead to an increase in anterior translational and anterolateral rotational (ALR) instability.

METHODS

Eight fresh-frozen cadaveric knees were tested using a six-degree-of-freedom robotic setup (KR 125, KUKA Robotics, Germany) with an attached optical tracking system (Optotrack Certus Motion Capture, Northern Digital, Canada). After the passive path from 0 to 90° was established, a simulated Lachman test and pivot-shift test as well as external rotation (ER) and internal rotation (IR) were applied at 0°, 30°, 60° and 90° of flexion under constant 200 N axial loading. All of the parameters were initially tested in the intact and ACL-deficient states, followed by two different types of posterolateral impression fractures. The dislocation height was 10 mm, and the width was 15 mm in both groups. The intraarticular depth of the fracture corresponded to half of the width of the posterior horn of the lateral meniscus in the first group (Bankart 1) and 100% of the meniscus width in the second group (Bankart 2).

RESULTS

There was a significant decrease in knee stability after both types of posterolateral tibial plateau fractures in the ACL-deficient specimens, with increased anterior translation in the simulated Lachman test at 0° and 30° of knee flexion (p = 0.012). The same effect was seen with regard to the simulated pivot-shift test and IR of the tibia (p = 0.0002). In the ER and posterior drawer tests, ACL deficiency and concomitant fractures did not influence knee kinematics (n.s.).

CONCLUSION

This study demonstrates that high-grade impression fractures of the posterolateral aspect of the tibial plateau increase the instability of ACL-deficient knees and result in an increase in translational and anterolateral rotational instability.

A fast, easy and reliable method for hamstrings graft size prediction in anterior cruciate ligament reconstruction

PURPOSE

The aim of this study is to describe and validate a simple and reliable method to pre-operatively predict the size of the ACL graft in the double strand technique with autologous semitendinosus-gracilis tendons on the same MRI used for ACL rupture diagnosis.

METHODS

The study included 92 patients, with a median age of 31 years (IQR 26-41 years), 73/92 (79%) of whom were males. All patients that underwent an ACL reconstruction with doubled ST + GT between 2017 and 2022 were counted in the study.

RESULTS

Overall, the median predicted graft diameter from MR imaging was similar to the actual graft diameter with no significant differences (n.s.). Regarding the comparison between predicted and actual graft size, concordance was 78/92 (85%, 95% CI 76-91%), with κ = 0.797 which corresponds to a level of agreement defined as "Strong". Tendon sizes calculated on pre-operative MRI were evaluated both with intra-observer and inter-observer reliability demonstrating a statistically reproducible method. The predicted graft was then compared to the reported one with a statistically significant reliability found.

CONCLUSION

This study can help the surgeons to perform a fast pre-operative planning of an ACL reconstruction for graft selection. If the planned graft with ST and GT is smaller than 8 mm, the clinician can decide to switch to a different type of graft or plan a different graft preparing technique and, therefore, reduce the risk of post-operative ligament re-rupture. The method proposed is reliable and reproducible. The major strength of the planning technique proposed is that it relies on data that are already available for the clinician before surgery, without the need of further analysis.

LEVEL OF EVIDENCE

IV.

Preserving the hamstring tendon insertion during ACL reconstruction with an autograft: Systematic literature review

INTRODUCTION

The hamstring tendons (gracilis and semitendinosus) are often used as an autograft for anterior cruciate ligament (ACL) reconstruction. Healing of this graft involves a slow biological process called ligamentization. To encourage this process, some authors have proposed preserving the insertion of the hamstring tendons.

HYPOTHESIS

Leaving the tibial insertion of the hamstring tendons intact will provide better early biological incorporation and superior tibial mechanical fixation resulting in various clinical advantages.

MATERIALS AND METHODS

In January 2022, a systematic literature review was carried out independently by two authors of the Medline, PubMed and Embase databases. The keywords used were "pedicular" or "pedicled" or "preservation of tibial attachment" or "hamstring tibial insertion" AND "ACL reconstruction". Each author's data was analyzed separately.

RESULTS

Sixteen articles were analyzed. Preserving the hamstring tibial insertion during ACL reconstruction improves the graft's biological incorporation during the initial postoperative phase according to clinical studies with MRI analysis and provides a mechanical advantage at the graft's tibial attachment according to biomechanical studies (construct up to 65% stiffer). There was no difference in the clinical and functional scores when compared to the conventional technique in which the hamstring tendons are detached from their tibial insertion.

DISCUSSION

The main conclusion of this systematic literature review was that preserving the hamstring tibial insertion during ACL reconstruction appears to improve the graft's ligamentization with biological and mechanical advantages relative to detaching the hamstring tendons. The clinical and functional results were comparable to other techniques. Prospective studies with large cohorts are still needed to confirm these findings.

LEVEL OF EVIDENCE

IV; Systematic review of literature.

After Anterior Cruciate Ligament Injury, Patients With Medicaid Insurance Experience Delayed Care and Worse Clinical Outcomes Than Patients With Non-Medicaid Insurance

Purpose

To evaluate the effects of socioeconomic factors on the operative treatment of anterior cruciate ligament injuries and outcomes following surgical reconstruction.

Methods

A retrospective cohort study of primary anterior cruciate ligament reconstruction surgeries at a single institution performed from 2011 to 2015 with minimum 2-year follow-up was conducted. Patient demographics, insurance type, workers' compensation status, surgical variables, International Knee Documentation Committee score, and failure were recorded from chart review. Education level and income were obtained via phone interview. Differences between functional outcome were compared between Medicaid and non-Medicaid groups.

Results

In total, 268 patients were included in the analysis (43 patients in the Medicaid group and 225 patients in the non-Medicaid group, overall mean follow-up of 3.1 ± 0.8 years). The Medicaid group demonstrated lower annual income (P < .001) and a lower level of completed education compared with the non-Medicaid group (P < .001). Patients who received Medicaid had a greater duration between time of initial knee injury and surgery compared with the those in non-Medicaid group (11.8 ± 16.3 months vs 6.1 ± 16.5 months, P < .001). At the time of follow-up, patients in the non-Medicaid group had a significantly greater International Knee Documentation Committee score compared with patients who received Medicaid (82.5 ± 13.8 vs 75.3 ± 20.8, P = .036).

Conclusions

Patients with Medicaid insurance were seen in the clinic significantly later after initial injury and had worse outcomes compared with patients with other insurance types. Also, patients in higher annual income brackets had significantly better clinical outcomes scores at a minimum of 2 years postoperatively.

Level of Evidence

Level III, retrospective cohort study.

Revision Rates After Primary Allograft ACL Reconstruction by Allograft Tissue Type in Older Patients

Background

While there is extensive literature on the use of allograft versus autograft in anterior cruciate ligament (ACL) reconstruction, there is limited clinical evidence to guide the surgeon in choice of allograft tissue type.

Purpose

To assess the revision rate after primary ACL reconstruction with allograft and to compare revision rates based on allograft tissue type and characteristics.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients who underwent primary allograft ACL reconstructions at a single academic institution between 2015 and 2019 and who had minimum 2-year follow-up were included. Exclusion criteria were missing surgical or allograft tissue type data. Demographics, operative details, and subsequent surgical procedures were collected. Allograft details included graft tissue type (Achilles, bone-patellar tendon-bone [BTB], tibialis anterior or posterior, semitendinosus, unspecified soft tissue), allograft category (all-soft tissue vs bone block), donor age, irradiation duration and intensity, and chemical cleansing process. Revision rates were calculated and compared by allograft characteristics.

Results

Included were 418 patients (age, 39 ± 12 years; body mass index, 30 ± 9 kg/m2). The revision rate was 3% (11/418) at a mean follow-up of 4.9 ± 1.4 years. There were no differences in revision rate according to allograft tissue type across Achilles tendon (3%; 3/95), BTB (5%; 3/58), tibialis anterior or posterior (3%; 5/162), semitendinosus (0%; 0/46), or unspecified soft tissue (0%; 0/57) (P = .35). There was no difference in revision rate between all-soft tissue versus bone block allograft (6/283 [2%] vs 5/135 [4%], respectively; P = .34). Of the 51% of grafts with irradiation data, all grafts were irradiated, with levels varying from 1.5 to 2.7 Mrad and 82% of grafts having levels of <2.0 Mrad. There was no difference in revision rate between the low-dose and medium-to high-dose irradiation cohorts (4% vs 6%, respectively; P = .64).

Conclusion

Similarly low (0%-6%) revision rates after primary ACL reconstruction were seen regardless of allograft tissue type, bone block versus all-soft tissue allograft, and sterilization technique in 418 patients with mean age of 39 years. Surgeons may consider appropriately processed allograft tissue with or without bone block when indicating ACL reconstruction in older patients.

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

BACKGROUND

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

PURPOSE

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

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

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

RESULTS

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

CONCLUSION

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

Low-Volume Surgeons Use Allograft in Younger Patients and Show Greater Rates of Revision Following Primary Allograft Anterior Cruciate Ligament Reconstruction Compared With High-Volume Surgeons

Purpose

To determine whether surgeon volume affects revision rate following primary anterior cruciate ligament reconstruction (ACLR) with allograft and to determine whether surgeon volume impacts allograft tissue type used.

Methods

All patients aged 14 years or older who underwent primary allograft ACLR at a large hospital system between January 2015 to December 2019 with minimum 2-year follow-up were included. Patients with double-bundle ACLR, multiligament reconstruction, and absent allograft type data were excluded. Surgeon volume was categorized as 35 or more ACLR/year for high-volume surgeons and less than 35 ACLR/year for low-volume surgeons. Revision was defined as subsequent ipsilateral ACLR. Patient characteristics, operative details, allograft type, and revision ACLR rates were retrospectively collected. Revision rate and allograft type were analyzed based on surgeon volume.

Results

A total of 457 primary allograft ACLR cases (mean age: 38.8 ± 12.3 years) were included. Low-volume surgeons experienced greater revision rates (10% vs 5%, P = .04) and used allograft in a younger population (37.6 vs 40.0 years old, P = .03) than high-volume surgeons. Subgroup analysis of the total cohort identified a significantly increased failure rate in patients <25 years old compared with ≥25 years old (30% vs 4%, P < .001). Allograft type selection varied significantly between surgeon volume groups, with low-volume surgeons using more bone-patellar tendon-bone (P < .001) and less semitendinosus allograft (P = .01) than high-volume surgeons. No differences in revision rate were observed based on allograft type (P = .71).

Conclusions

There was a greater revision rate following primary allograft ACLR among low-volume surgeons compared with high-volume surgeons. Low-volume surgeons also used allograft in a younger population than did high-volume surgeons.

Level of Evidence

Level III, retrospective comparative prognostic trial.

rAAV TGF-β and FGF-2 Overexpression via pNaSS-Grafted PCL Films Stimulates the Reparative Activities of Human ACL Fibroblasts

Lesions in the human anterior cruciate ligament (ACL) are frequent, unsolved clinical issues due to the limited self-healing ability of the ACL and lack of treatments supporting full, durable ACL repair. Gene therapy guided through the use of biomaterials may steadily activate the processes of repair in sites of ACL injury. The goal of the present study was to test the hypothesis that functionalized poly(sodium styrene sulfonate)-grafted poly(ε-caprolactone) (pNaSS-grafted PCL) films can effectively deliver recombinant adeno-associated virus (rAAV) vectors as a means of overexpressing two reparative factors (transforming growth factor beta-TGF-β and basic fibroblast growth factor-FGF-2) in primary human ACL fibroblasts. Effective, durable rAAV reporter red fluorescent protein and candidate TGF-β and FGF-2 gene overexpression was achieved in the cells for at least 21 days, especially when pNaSS-grafted PCL films were used versus control conditions, such as ungrafted films and systems lacking vectors or films (between 1.8- and 5.2-fold differences), showing interactive regulation of growth factor production. The expression of TGF-β and FGF-2 from rAAV via PCL films safely enhanced extracellular matrix depositions of type-I/-III collagen, proteoglycans/decorin, and tenascin-C (between 1.4- and 4.5-fold differences) in the cells over time with increased levels of expression of the specific transcription factors Mohawk and scleraxis (between 1.7- and 3.7-fold differences) and without the activation of the inflammatory mediators IL-1β and TNF-α, most particularly with pNaSS-grafted PCL films relative to the controls. This work shows the value of combining rAAV gene therapy with functionalized PCL films to enhance ACL repair.

Modified Lemaire Tenodesis Forces in Cadaveric Specimens Are Not Affected by Random Small-Scale Variations in the Femoral Insertion Point During Active Knee Joint Flexion-Extension

Purpose

To directly measure lateral extra-articular tenodesis (LET) forces supporting anterior cruciate ligament reconstruction (ACLR) during dynamic flexion-extension cycles induced by simulated active muscle forces, to investigate the influence of random surgical variation in the femoral LET insertion point around the target insertion position, and to determine potential changes to the extension behavior of the knee joint in a cadaveric model.

Methods

After iatrogenic anterior cruciate ligament deficiency and simulated anterolateral rotatory instability, 7 fresh-frozen cadaveric knee joints were treated with isolated ACLR followed by combined ACLR-LET. The specimens were tested on a knee joint test bench during active dynamic flexion-extension with simulated muscle forces. LET forces and the degree of knee joint extension were measured. Random variation in the LET insertion point around the target insertion position was postoperatively quantified by computed tomography.

Results

In extension, the median LET force increased to 39 ± 2 N (95% confidence interval [CI], 36 to 40 N). In flexion over 70°, the LET was offloaded (2 ± 1 N; 95% CI, 0 to 2 N). In this study, small-scale surgical variation in the femoral LET insertion point around the target position had a negligible effect on the graft forces measured. We detected no difference in the degree of knee joint extension after combined ACLR-LET (median, 1.0° ± 3.0°; 95% CI, -6.2° to 5.2°) in comparison with isolated ACLR (median, 1.1° ± 3.3°; 95% CI, -6.7° to 6.1°; P = .62).

Conclusions

LET forces in combined ACLR-LET increased to a limited extent during active knee joint flexion-extension independent of small-scale variation around 1 specific target insertion point. Combined ACLR-LET did not change knee joint extension in comparison with isolated ACLR under the testing conditions used in this biomechanical study.

Clinical Relevance

Low LET forces can be expected during flexion-extension of the knee joint. Small-scale deviations in the femoral LET insertion point around the target insertion position in the modified Lemaire technique might have a minor effect on graft forces during active flexion-extension.

Lateral Extra-articular Tenodesis with Iliotibial Band Using Knotless All-Suture Anchor Femoral Fixation

Common injuries, such as anterior cruciate ligament (ACL) tears, can result in both anterior and rotational instability of the knee. An arthroscopic anterior cruciate ligament reconstruction (ACLR) method has been shown to be effective in restoring anterior translational stability, but this could be followed by persistent rotational instability by means of residual pivot shifts or repeat instability episodes. Alternative techniques, such as a lateral extraarticular tenodesis (LET), has been proposed as a technique for preventing persistent rotational instability following ACLR. This article presents a case of a LET using an autologous central slip of iliotibial (IT) band with fixation to the femur using a 1.8-mm knotless all-suture anchor.

Graft-Specific Surgical and Rehabilitation Considerations for Anterior Cruciate Ligament Reconstruction with the Quadriceps Tendon Autograft

Anterior cruciate ligament reconstruction (ACLR) with a bone-patellar tendon-bone (BPTB) or hamstring tendon (HT) autograft has traditionally been the preferred surgical treatment for patients returning to Level 1 sports. More recently, international utilization of the quadriceps tendon (QT) autograft for primary and revision ACLR has increased in popularity. Recent literature suggests that ACLR with the QT may yield less donor site morbidity than the BPTB and better patient-reported outcomes than the HT. Additionally, anatomic and biomechanical studies have highlighted the robust properties of the QT itself, with superior levels of collagen density, length, size, and load-to-failure strength compared to the BPTB. Although previous literature has described rehabilitation considerations for the BPTB and HT autografts, there is less published with respect to the QT. Given the known impact of the various ACLR surgical techniques on postoperative rehabilitation, the purpose of this clinical commentary is to present the procedure-specific surgical and rehabilitation considerations for ACLR with the QT, as well as further highlight the need for procedure-specific rehabilitation strategies after ACLR by comparing the QT to the BPTB and HT autografts.

Level of Evidence

Level 5.

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

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

Morphological Changes in the Tibial Tunnel After ACL Reconstruction With the Outside-In Technique and Adjustable Suspensory Fixation

Background

Anterior cruciate ligament reconstruction (ACLR) using the complete tibial tunnel technique and adjustable-loop cortical suspensory fixation is known to leave a "dead space" that holds the loop device in the tibial tunnel. The consequence of the dead space and its effect on graft healing are still uncertain.

Purpose

To investigate morphological changes in the tibial tunnel and their effect on graft healing, and to identify factors affecting bone healing in the tibial loop tunnel after ACLR with a quadrupled semitendinosus tendon autograft using adjustable suspensory fixation.

Study Design

Case series; Level of evidence, 4.

Methods

Included were 48 patients (34 male, 14 female; mean age, 25.2 ± 5.6 years) who underwent ACLR with a quadrupled semitendinosus tendon autograft using adjustable suspensory fixation. To evaluate tibial tunnel morphology, computed tomography was performed at 1 day and 6 months postoperatively. At 1 year postoperatively, graft healing was assessed on magnetic resonance imaging using the graft signal-to-noise quotient (SNQ). Multivariate regression and correlation analyses were performed to determine any associations between volumetric changes in bone healing and operative variables.

Results

At 6 months after ACLR, a mean of 63.2% of the tibial loop tunnel was filled by bone. Multivariate regression analysis showed that remnant preservation was significantly associated with the loop tunnel filling rate (P < .001). At 1 year after ACLR, the tibial loop tunnel was almost completely closed (98.5%). There were no correlations between loop tunnel volume and graft integration or graft SNQ. A significant but weak correlation was found between graft tunnel volume and intratunnel graft SNQ (P = .10) as well as integration grade in the tibial tunnel (P = .30).

Conclusion

Excellent bone filling in the tibial loop tunnel was seen at 1 year after ACLR. Remnant preservation was significantly associated with the loop tunnel filling rate. A weak correlation was found between graft tunnel volume and intratunnel graft SNQ as well as integration grade in the tibial tunnel.

High revision arthroscopy rate after ACL reconstruction in men's professional team sports

PURPOSE

The study analysed unique data on anterior cruciate ligament (ACL) injuries among German professional male team sports over five consecutive seasons with the aim of improving medical outcomes in the future. Sport-specific differences in injury occurrence, concomitant injuries, timing of ACL reconstruction, graft type selection and short-term complications were examined.

METHODS

This retrospective study analysed trauma insurance data on all complete ACL tears from players with at least one competitive match appearance in the two highest divisions of German male basketball, ice hockey, football and handball. Each complete ACL tear registered by clubs or physicians between the 2014/15 and 2018/19 seasons with the German statutory accidental insurance for professional athletes (VBG) as part of occupational accident reporting was included.

RESULTS

In total, 189 out of 7517 players (2.5%) sustained an ACL injury, mainly in handball (n = 82; 43.4%) and football (n = 72; 38.1%) followed by ice hockey (n = 20; 10.6%) and basketball (n = 15; 7.9%).Seventeen players (9.0%) also sustained a second ACL injury. Thus, 206 ACL injuries were included in the analysis. The overall match incidence of ACL injuries was 0.5 per 1000 h and was highest in handballs (1.1 injuries per 1000 h). A total of 70.4% of ACL injuries involved concomitant injury to other knee structures, and 29.6% were isolated ACL injuries. The highest rate of isolated ACL injuries was seen in ice hockey (42.9%). All ACL injuries, except for one career-ending injury, required surgery. In the four analysed team sports, hamstring tendons (71.4%) were the most commonly used grafts for ACL reconstruction; football had the highest percentage of alternative grafts (48.7%). During rehabilitation, 22.9% of all surgically treated ACL injuries (n = 205) required at least two surgical interventions, and 15.6% required revision arthroscopy. The main cause of revision arthroscopy (n = 32; 50.0%) was range-of-motion deficit due to arthrofibrosis or cyclops formation.

CONCLUSION

The present study shows an overall high rate of revision arthroscopy after ACLR (15.6%), which should encourage surgeons and therapists to evaluate their treatment and rehabilitation strategies in this specific subpopulation. Hamstring tendon grafts are most commonly used for ACL reconstruction but have the highest revision and infection rates. Handball shows the highest ACL injury risk of the four evaluated professional team sports. Concomitant injuries occur in the majority of cases, with the highest share of isolated ACL injuries occurring in ice hockey.

LEVEL OF EVIDENCE

Level III.

"Cost-effectiveness of ACL treatment is dependent on age and activity level: a systematic review"

PURPOSE

To systematically review the literature on health-economic evaluations of anterior cruciate ligament (ACL) injury between reconstruction surgery (ACLR) and non-operative treatment (NO) and suggest the most cost-effective strategy between the two.

METHODS

All economic studies related to ACLR versus NO post-ACL injury, either trial based or model based, published until April 2022, were identified using PubMed and Embase. The methodology of the health-economic analysis for each included study was categorized according to the four approaches: cost-minimization analysis (CMA), cost-effectiveness analysis (CEA), cost-benefit analysis (CBA), and cost-utility analysis (CUA). The quality of each included study was assessed using the Consensus on Health Economic Criteria (CHEC) list.

RESULTS

Of the seven included studies, two compared the strategies of early ACLR and NO alone, and five compared early ACLR and NO with optional delayed ACLR. All studies performed a CUA, and one study performed a CBA additionally. The CHEC scores of the included studies can be considered good, ranging from 15 to 18 from a maximum of 19. Applying the common standard threshold of $50,000 per QALY, six studies in young people with high-activity levels or athletes showed that early ACLR would be preferred over either NO alone or delayed ACLR. Of six studies, two even showed early ACLR to be the dominant strategy over either NO alone or delayed ACLR, with per-patient cost savings of $5,164 and $1,803 and incremental per-patient QALY gains of 0.18 and 0.28, respectively. The one study in the middle-aged people with a moderate activity level showed that early ACLR was not more cost-effective than delayed ACLR, with ICER $101,939/QALY using the societal perspective and ICER $63,188/QALY using the healthcare system perspective.

CONCLUSION

Early ACLR is likely the more cost-effective strategy for ACL injury cases in athletes and young populations with high-activity levels. On the other hand, non-operative treatment with optional delayed ACLR may be the more cost-effective strategy in the middle age population with moderate activity levels.

LEVEL OF EVIDENCE

Systematic review of level III studies.

Preoperative quantitative pivot shift does not correlate with in vivo kinematics following ACL reconstruction with or without lateral extraarticular tenodesis

PURPOSE

Quantitative pivot shift (QPS) testing using PIVOT technology can detect high- and low-grade rotatory knee instability following anterior cruciate ligament injury or reconstruction (ACLR). The aim of this project was to determine if preoperative QPS correlates with postoperative knee kinematics in the operative and contralateral, healthy extremity following ACLR with or without lateral extraarticular tenodesis (LET) using a highly precise in vivo analysis system. A positive correlation between preoperative QPS and postoperative tibial translation and rotation following ACLR with or without LET in the operative and healthy, contralateral extremity was hypothesized.

METHODS

Twenty patients with ACL injury and high-grade rotatory knee instability were randomized to undergo anatomic ACLR with or without LET as part of a prospective randomized trial. At 6 and 12 months postoperatively, in vivo kinematic data were collected using dynamic biplanar radiography superimposed with high-resolution computed tomography scans of patients' knees during downhill running. Total anterior-posterior (AP) tibial translation and internal-external tibial rotation were measured during the gait cycle. Spearman's rho was calculated for preoperative QPS and postoperative kinematics.

RESULTS

In the contralateral, healthy extremity, a significant positive correlation was seen between preoperative QPS and total AP tibial translation at 12 months postoperatively (r_s = 0.6, p < 0.05). There were no additional significant correlations observed between preoperative QPS and postoperative knee kinematics at 6 and 12 months postoperatively in the operative and contralateral, healthy extremity for combined isolated ACLR and ACLR with LET patients as well as isolated ACLR patients or ACLR with LET patients analyzed separately.

DISCUSSION

The main finding of this study was that there was a significant positive correlation between preoperative QPS and total AP tibial translation at 12 months postoperatively in the contralateral, healthy extremity. There were no significant correlations between preoperative QPS and postoperative in vivo kinematics at 6 and 12 months following ACLR with or without LET. This suggests that QPS as measured with PIVOT technology does correlate with healthy in vivo knee kinematics, but QPS does not correlate with in vivo kinematics following ACLR with or without LET.

The orientation of the ALL femoral tunnel to minimize collision with the ACL tunnel depends on the need or not of far-cortex drilling

PURPOSE

To (1) evaluate the optimal drill orientation of the anterolateral ligament (ALL) femoral tunnel to minimize collision with the anterior cruciate ligament (ACL) femoral tunnel during anatomical ACL reconstruction according to the need for far-cortex drilling and (2) investigate the geometric factors that affect tunnel collision secondary to drill orientation of the ALL femoral tunnel.

METHODS

A three-dimensional femoral model of patients who underwent anatomical single-bundle ACL reconstruction between 2015 and 2016 was constructed, and the geometric factors were evaluated. Virtual ALL femoral tunnels were created to simulate 45 drilling conditions. For each condition, whether the virtual ALL femoral tunnel and its trajectory violated the femoral cortex and the minimum distance between tunnels was investigated.

RESULTS

Thirty-nine subjects were included. Overall violation rates of the femoral cortex by the ALL tunnels and its trajectories were 11.1% (195 of 1755 conditions) and 40.7% (714 of 1755 conditions), respectively. A drilling angle of axial 0° and coronal - 40° showed the longest minimum distance between tunnels without femoral cortex violation by the ALL tunnel (6.3 ± 4.0 mm; collision rate 2.6% [1 of 39 subjects]). With simultaneous consideration of the ALL tunnel's trajectory representing far-cortex drilling, a drill angle of axial 40° and coronal 10° showed the longest minimum distance between tunnels without femoral cortex violation (0.6 ± 3.9 mm; collision rate 38.5% [15 of 39 subjects]). For surgical techniques requiring far-cortex drilling, regression analyses were performed on geometric factors that could affect tunnel collision, which revealed that the sagittal inclination angle of the ACL and the distance between the ACL femoral tunnel's outlet and ALL's femoral attachment were associated with tunnel collision.

CONCLUSION

The optimal drill orientations of the ALL femoral tunnel to minimize collision with the ACL femoral tunnel were axial 0° and coronal - 40° for surgical techniques not requiring far-cortex drilling and axial 40° and coronal 10° for techniques requiring far-cortex drilling. For techniques requiring far-cortex drilling, additional adjustment for orientation of the ACL femoral tunnel is required to reduce the risk of tunnel collision. Therefore, an individualized surgical strategy should be applied according to the graft fixation method of the ALL femoral tunnel.

A novel home-based rehabilitative knee brace system is a viable option for postoperative rehabilitation after anterior cruciate ligament reconstruction: a report of 15 cases

Purpose

To investigate the functional outcomes for patients who used a novel home-based rehabilitative system during the postoperative period after anterior cruciate ligament (ACL) reconstructions.

Methods

Patients undergoing ACL reconstruction surgeries were prospectively enrolled. A home-based rehabilitation system, which is composed of a knee brace with a motion tracker, a mobile app, and a web portal, was applied. Patients could complete the rehabilitation exercise through the audio guidance and the real-time tracking system which displayed the achieved motions on the user interface of the app. Feedbacks from the patients, including the International Knee Documentation Committee (IKDC) scores, were collected and uploaded to the web portal. Each patient would meet a specialized physical therapist face-to-face once a month. At postoperative 6 months, every patient received a GNRB arthrometer examination and a Cybex isokinetic dynamometer examination.

Results

A total of 15 patients (10 males and 5 females) were enrolled and followed for at least 6 months. The mean time of return to full knee extension was 1.5 months.

The mean difference in laxity measured by GNRB arthrometer at 134 N significantly improved at postoperative 6 months (1.8 ± 1.6 mm) compared to that measured preoperatively (3.4 ± 1.9 mm) (p = 0.024). The peak torques of flexor and extensor muscles measured by Cybex isokinetic dynamometer remained unchanged at postoperative 6 months (p = 0.733 and 0.394, respectively). The patients’ IKDC score became smaller at postoperative 1 month (p = 0.011) and significantly improved at postoperative 6 months (p = 0.002).

Conclusion

Using a home-based rehabilitative knee brace system after ACL reconstruction is a viable option as patients maintained their knee muscle strengths maintained their muscle strength and achieve similar or better knee range of motion six months postoperatively.

Medial meniscus tears are most prevalent in type I ACL tears, while type I ACL tears only account for 8% of all ACL tears

PURPOSE

This study aimed to assess the distribution of different anterior cruciate ligament (ACL) tear locations in different magnetic resonance imaging (MRI) planes, and to explore the relationships of ACL tear types with both meniscus injuries and bone bruising.

METHODS

A retrospective study was performed in patients under 60 years old who underwent MRI scans in the sagittal and coronal oblique planes of the knee for ACL tears between 2014 and 2020. Patients with reports of chronic tears, partial tears, or prior surgeries were excluded. Tear locations were classified into five types, and the meniscus tear measurement variables included the presence of ramp, root, bucket-handle, and other types of tears. All injuries were confirmed by arthroscopy. Meanwhile, the presence and location of bone bruising were analysed and scored with the Whole-Organ Magnetic Resonance Imaging Score (WORMS) bone bruising subscale.

RESULTS

A total of 291 patients were included. The prevalence rates of type I and type III injuries were 23/291 (7.9%) and 145/291 (49.8%) in the sagittal plane and 22/291 (7.6%) and 179/291 (61.5%) in the oblique coronal plane, respectively. The prevalence of medial meniscus tears with ACL tears was 126/291 (43.3%), while that of lateral meniscus tears with ACL tears was 77/291 (26.5%). The highest prevalence of medial meniscus injury with ACL tears was 15/22 (68.2%) for type I injuries. Bone bruises were located on the lateral femoral center in 125 patients (46%) and on the lateral tibia posterior in 132 patients (48%); the common areas of bone bruising were slightly correlated with type III ACL tears but not correlated with type I ACL tears.

CONCLUSION

The plane in which an MRI scan is performed affects the classification of ACL tears. The tear type is associated with the prevalence of medial meniscus injuries, and medial meniscus tears are most prevalent in type I ACL tears.

LEVEL OF EVIDENCE

IV.

ACL repair for athletes?

Background

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

Current science of ACLSR

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

Clinical outcome of ACLSR

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

Conclusion

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