Patient demographic and surgical characteristics in anterior cruciate ligament reconstruction: a description of registries from six countries

Exosome-loaded hyaluronic acid hydrogel composite with oxygen-producing 3D printed polylactic acid scaffolds for bone tissue repair and regeneration

Bone defects can interfere with bone healing by disrupting the local environment, resulting in vascular damage and hypoxia. Under these conditions, insufficient oxygen availability is a significant factor that exacerbates disease by blocking angiogenesis or osteogenesis. Exosomes play a crucial role in intercellular communication and modulation of inflammation to aid bone regeneration. However, the distance between exosomes and areas of damage can hinder efficient bone generation and cell survival. To overcome this limitation, we fabricated a continuous oxygen-supplying composite scaffold, with the encapsulation of calcium peroxide in a polylactic acid three-dimensional (3D) printing construct (CPS), as both an oxygen source and hydroxyapatite (HAP) precursor. Furthermore, bone marrow mesenchymal stem cell (BMSC)-derived exosomes were incorporated into hyaluronic acid (HA) hydrogels to stimulate cell growth and modulate inflammation. The release of exosomes into cells leads to an increase in alkaline phosphatase production. In vivo results demonstrated that the composite scaffold regulated the inflammatory microenvironment, relieved tissue hypoxia, and promoted new bone formation. These results indicate that the synergistic effect of exosomes and oxygen promoted the proliferation of BMSCs, alleviated inflammation and exhibited excellent osteogenic properties. In conclusion, this osteogenic functional composite scaffold material offers a highly effective approach for bone repair.

Risk factors and prevalence of ramp lesions in ACL ruptures: An analysis from the registry of the Francophone Arthroscopic Society

PURPOSE

The study aimed to estimate the prevalence of ramp lesions among patients undergoing anterior cruciate ligament (ACL) reconstruction and identify risk factors associated with these lesions.

METHODS

A retrospective, multicentre cohort study was conducted using data from the Francophone Arthroscopic Society's registry, including 5359 patients who underwent ACL reconstruction (ACLR) from June 2020 to June 2023. Potential risk factors for ramp lesion such as patient demographics, revision surgery, pivot shift, side-to-side anteroposterior laxity, medial collateral ligament (MCL) injury, lateral meniscal tear and the volume of ligament remnant were evaluated using multivariate regression analyses. BMI and delay to surgery were also assessed.

RESULTS

Ramp lesions were identified in 822 patients (15.3%). Univariate analysis identified male sex, younger age, revision surgery, lateral meniscal injury, percentage of ACL remnant (all p < 0.0001) and pivot shift (p = 0.0103) as significant risk factors. MCL injury was associated with a lower risk (p < 0.0001). In multivariate analysis, male sex, younger age, revision surgery, lateral meniscal injury and percentage of ACL remnants remained significant risk factors, while MCL injury remained a protective factor. The anteroposterior laxity wasn't a significant predictor in either analysis. In subgroup analysis, there were no differences concerning body mass index (n.s) and the delay to surgery (n.s).

CONCLUSION

The study identified male sex, younger age, revision surgery, lateral meniscal injury and pourcentage of ACL remnant as significant risk factors for ramp lesions, with MCL injury acting as a protective factor. This will help regarding the suspicion and identification of ramp lesions.

LEVEL OF EVIDENCE

Level III.

Male sex, revision surgery, low volume of anterior cruciate ligament remnant, and significant instability are risk factors for Posterior Root Tear of the Lateral Meniscus in patients undergoing Anterior Cruciate Ligament Reconstruction

PURPOSE

This multicenter study aimed to determine the incidence of lateral meniscus posterior root tears (LMPRTs) in patients undergoing ACL reconstruction and identify associated risk factors.

METHODS

We conducted a retrospective, multicenter study using data from the Francophone Arthroscopic Society's registry. The study included all the patients in the registry who underwent ACL reconstruction surgery between June 2020 and June 2023, we excluded incomplete data. We compared delay from injury to surgery between LMPRTs group and No LMPRTs group. Variables investigated as potential risk factors for LMPRTs included age, sex, nature of surgery (primary or revision), pivot shift test result, side-to-side laxity under anesthesia, presence of ACL remnant, occurrence of medial meniscal tear, and presence of collateral ligament injury. Risk factors were analyzed using a logistic regression model.

RESULTS

Among the 5359 patients analyzed, LMPRTs occurred in 7.0% (n=375) of cases during ACL reconstruction. Mean age at surgery was 29.3 +/- 10.3 years old [11-77]. Concerning delay to surgery, the mean time was 8.4 +/- 23.1 weeks [0.0-347.2] in the No LMPRTs group and 6.5 +/- 10.2 weeks [0.2-61.6] in the LMPRTs group (p = 0.109). Univariate analysis revealed that male sex (p < 0.001), revision surgery (p < 0.001), medial meniscal injury (p = 0.007), ACL remnant (0% vs > 70%, <10% vs > 70%, 10 to 30% vs > 70%, 30 to 50% vs > 70%, 50 to 70% vs > 70%; p < 0.001) and higher pivot shift grade (p = 0.011) were significantly associated with a presence of LMPRTs. Age, side-to-side laxity, and collateral ligament injury were not found to be significant risk factor In multivariate analysis : male sex, revision surgery, pivot shift test result and a low volume of ACL remnant remained significant. Side to side laxity was also a significant factor in multivariate analysis.

CONCLUSION

This study identified male sex, revision surgery, low volume of ACL remnant, side to side laxity and higher grade of pivot shift as significant risk factors for LMPRTs during ACL reconstruction.

Improvements in Quality, Safety and Costs Associated with Use of Implant Registries Within a Health System

BACKGROUND

Clinical quality registries (CQRs) are intended to enhance quality, safety, and cost reduction using real-world data for a self-improving health system. Starting in 2001, Kaiser Permanente established several medical device CQRs as a quality improvement initiative. This report examines the contributions of these CQRs on improvement in health outcomes, changes in clinical practice, and cost-effectiveness over the past 20 years.

METHODS

Eight implant registries were instituted with standardized collection from the electronic health record and other institutional data sources of patient characteristics, medical comorbidities, implant attributes, procedure details, surgical techniques, and outcomes (including complications, revisions, reoperations, hospital readmissions, and other utilization measures). A rigorous quality control system is in place to improve and maintain the quality of data. Data from the Implant Registries form the basis for multiple quality improvement and patient safety initiatives to minimize variation in care, promote clinical best practices, facilitate recalls, perform benchmarking, identify patients at risk, and construct reports about individual surgeons.

RESULTS

Following the inception of the Implant Registries, there was an observed (1) reduction in opioid utilization following orthopedic procedures, (2) reduction in use of bone morphogenic protein during lumbar fusion allowing for cost savings, (3) reduction in allograft for anterior cruciate ligament reconstruction and subsequent decrease in organizationwide revision rates, (4) cost savings through expansion of same-day discharge programs for joint arthroplasty, (5) increase in the use of cement fixation in the hemiarthroplasty treatment of hip fracture, and (6) organizationwide discontinuation of an endograft device associated with a higher risk for adverse outcomes following endovascular aortic aneurysm repair.

CONCLUSION

The use of Implant Registries within our health system, along with clinical leadership and organizational commitment to a learning health system, was associated with improved quality and safety outcomes and reduced costs. The exact mechanisms by which such registries affect health outcomes and costs require further study.

Use of electromyographic biofeedback in rehabilitation following anterior cruciate ligament reconstruction: a systematic review and meta-analysis

BACKGROUND

Rehabilitation following anterior cruciate ligament (ACL) reconstruction surgery is essential to regain functionality and return to previous activity level. Electromyographic biofeedback may be an effective intervention for rehabilitation of patients following ACL surgery.

OBJECTIVE

To synthesize the available evidence on the effect of electromyographic biofeedback in the treatment of quadriceps strength following ACL surgery.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

PubMed, EMBASE, CENTRAL and Epistemonikos were searched.

ELIGIBILITY CRITERIA

Randomized clinical trials with patients undergoing ACL reconstruction surgery comparing biofeedback with a standard rehabilitation control group.

DATA EXTRACTION AND DATA SYNTHESIS

Two authors selected articles and performed data extraction. The analysed outcomes were strength, function, pain, knee extension and balance. The risk of bias of individual studies was assessed using the Cochrane Risk of Bias Tool. Results were combined through random-effects meta-analysis, reporting mean differences.

RESULTS

Eight articles were included in the qualitative analysis, and four articles were included in the quantitative analysis. The interventions lasted between 4 and 12 weeks. Three studies evaluated the effect of biofeedback on quadriceps strength; of these, two studies showed a significant difference in favour of the biofeedback group. In addition, biofeedback was found to improve knee extension [standardized mean difference - 1.3, 95% confidence interval (CI) - 1.74 to -0.86] and balance (one study). There was no significant difference in Lysholm score (mean difference -6.21, 95% CI -17.51 to 5.08; I2 =59%) or pain between the biofeedback group and the control group.

CONCLUSION

Electromyographic biofeedback in knee rehabilitation could be useful following ACL reconstruction surgery.

KEY MESSAGES

SYSTEMATIC REVIEW REGISTRATION NUMBER: PROSPERO (CRD42020193768).

Validating the capture rate of revisions by the New Zealand ACL Registry: An analysis of all-cause reoperation following primary ACL reconstruction

PURPOSE

To validate the New Zealand Anterior Cruciate Ligament (ACL) Registry's capture rate of revisions by cross-referencing Registry data with reoperations data recorded by the Accident Compensation Corporation (ACC) and identify risk factors for all-cause reoperation.

METHODS

Primary ACL reconstructions performed between April 2014 and September 2019 were individually matched on a record-by-record basis between the two databases. The ACC database was used to identify patients who underwent a reoperation with manual review of operation notes to identify whether a revision or other procedure was performed. This was combined with the number of revisions separately recorded in the New Zealand ACL Registry, which was used as the denominator value to calculate the Registry's capture rate of revisions. Patient and surgical data recorded in the Registry were analysed to identify independent predictors for all-cause reoperation.

RESULTS

A total of 8046 primary ACL reconstructions were matched between the New Zealand ACL Registry and the ACC databases. The reoperation rate was 8.9% (n = 715) at a mean follow-up of 2.5 years. Meniscal-related procedures were the most common reoperation (n = 299, 3.7%), followed by revision ACL reconstruction (n = 219, 2.7%), arthrofibrosis (n = 185, 2.3%), cartilage (n = 56, 0.7%) and implants (n = 32, 0.4%). The New Zealand ACL Registry captured 96% of revisions. Younger age (hazard ratio [HR] > 1.4, p < 0.001), earlier surgery (HR > 1.3, p = 0.05), concurrent meniscal repair (medial meniscus HR = 1.9, p < 0.001 and lateral meniscus HR = 1.3, p = 0.022) and hamstring tendon autografts (HR = 1.4, p = 0.001) were associated with a higher risk of reoperation.

CONCLUSION

The New Zealand ACL Registry captured 96% of revisions. Risk factors for all-cause reoperation included younger age, earlier surgery, meniscal repair and hamstring tendon autografts.

LEVEL OF EVIDENCE

Level III.

Strategies for knee stabilising and pivot-shift avoidance in a step-down and cross-over task observed sub-acutely after anterior cruciate ligament reconstruction

BACKGROUND

Individuals with a recent anterior cruciate ligament reconstruction may demonstrate an altered movement strategy for protecting the knee and maintaining stability. Altered knee movement might lead to abnormal intra-articular load, potentially contributing to early knee osteoarthritis onset. A protective strategy may be particularly evident during active tasks that induce a pivot-shift manoeuvre, such as a step-down and cross-over task. In this study, we investigated whether knee joint mechanics and muscle activity differed between participants early (∼3 months) following reconstruction (n = 35) to uninjured controls (n = 35) during a step-down and cross-over task with a 45° change-of-direction.

METHODS

We used motion capture, force plates and surface electromyography to compare time-normalised curves of sagittal and transverse-plane knee mechanics and muscle activity during the cross-over phase between groups using functional t-tests. We also compared knee mechanics between sides within the injured group and compared discrete outcomes describing the cross-over phase between groups.

FINDINGS

Compared to controls, the injured participants had greater knee flexion angle and moment, lower internal rotation moment, more preparatory foot rotation of the pivoting leg, a smaller cross-over angle, and a longer cross-over phase for both the injured and uninjured sides. The injured leg also had greater biceps femoris and vastus medialis muscle activity compared to controls and different knee mechanics than the uninjured leg.

INTERPRETATION

Individuals with anterior cruciate ligament reconstruction showed a knee-stabilising and pivot-shift avoidance strategy for both legs early in rehabilitation. These results may reflect an altered motor representation and motivate considerations early in rehabilitation.

Satisfactory 5-year functional outcomes following primary ACL reconstructions from the UK National Ligament Registry

PURPOSE

The aim of this study was to describe the 10-year findings from the UK National Ligament Registry (NLR).

METHODS

A retrospective review was performed for prospectively collected data on the NLR between January 2013 and December 2022. All patients who underwent primary ACL reconstruction (ACLR) on the registry were included. Surgical characteristics were analysed, including surgeon grade and case volume, concomitant knee procedures, venous thromboembolic prophylaxis, graft characteristics, femoral and tibial tunnel drilling, and fixation methods. Clinical outcomes were collected preoperatively and at 6 months, 1 year, 2 years and 5 years following the index procedure.

RESULTS

During the study period, 17,492 unilateral ACLR procedures were recorded. Autograft was used in 98%, most commonly a combined semitendinosus and gracilis graft (77%) or patella tendon graft (31%). Allograft was used in only 1% of the patients. In 52% of cases, ACLR was associated with an additional procedure, with isolated medial meniscal surgery being the most common (21%). Femoral tunnel drilling was mostly performed through an anteromedial portal (73%) and tibial tunnel drilling using an outside-in technique (92%). The most common method of femoral graft fixation was with an Endobutton fixed loop suspensory device (77%), while interference screws predominated for tibial tunnel fixation (86%). Patients who underwent ACLR surgery showed significant improvement in their functional outcome scores at six months, 1 year, 2 years and 5 years postoperatively.

CONCLUSION

Data from the NLR shows a detailed description of the current trends and evolution of ACLR in the United Kingdom over the last 10 years. Satisfactory functional outcomes were observed 5 years postoperatively. This study provides useful information on the prevalence of ACL-associated injuries and current surgical techniques with the aim of improving the quality of clinical care and patients' outcomes. Moreover, it provides surgeons with a benchmark against which to compare current practices and functional outcomes following ACLR across the United Kingdom.

LEVEL OF EVIDENCE

Level III.

Ten-year results from the UK National Ligament Registry: Patient characteristics and factors predicting nonresponders for completion of outcome scores

PURPOSE

The aim of this study was to report the demographic and mechanism of injury data in the UK National Ligament Registry (NLR) at 10 years and determine factors leading to poor compliance with completion of Patient-Reported Outcome Scores (PROMs).

METHODS

A retrospective review was performed for prospectively collected data on the NLR between January 2013 and December 2022. All patients who underwent primary anterior cruciate ligament reconstruction (ACLR) were included. Patient demographics, mechanism of injury and patient compliance with completing PROMs were analysed. Patient characteristics were further analysed in relation to compliance with completing the different PROMs at the predefined time points. Patients were identified as nonresponders if they had not completed either 1- or 2-year postoperative Knee injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

A total of 17,492 patients were included in this study. The average age for patients undergoing ACLR between 2013 and 2022 was 29.4 (SD, 10.3). Seventy percent were men and 30% women. Football was the most common activity associated with an ACL injury. Patient compliance with recording PROMs was 55% preoperatively and 37%, 32% and 24% at 1-, 2- and 5-year postoperative follow-up, respectively. Nonresponders represented 54% of eligible patients. Multivariate analyses showed that sex, age, smoking, time interval between injury and surgery and low socioeconomic status were associated with low compliance with postoperative PROM completion (p < 0.001).

CONCLUSION

This study reports the demographic characteristics for patients on the NLR since 2013. Male sex, young age, increased waiting time between injury and surgery, smoking and lower socioeconomic class were predictors of low compliance with completion of postoperative PROMs on the UK NLR. Understanding the factors that affect patient compliance with PROMs improves our ability to provide targeted interventions and information to specific patient populations with the aim of enhancing inclusiveness and representation of population in the registry.

LEVEL OF EVIDENCE

Level III.

Influence of Surgeon Experience and Clinic Volume on Subjective Knee Function and Revision Rates in Primary ACL Reconstruction: A Study from the Swedish National Knee Ligament Registry

Background

Anterior cruciate ligament reconstruction (ACLR) performed by high-volume surgeons/clinics has been associated with increased graft individualization and decreased operating times, complication rates, and total costs.

Purpose

To investigate the influence of surgeon/clinic volume on subjective knee function and revision surgery rates at 2 years after primary ACLR.

Study Design

Cohort study; Level of evidence, 3.

Methods

Data from the Swedish National Knee Ligament Registry were used to study patients who underwent primary ACLR between 2008 and 2019. Surgeons/clinics were categorized based on a combination of total caseload volume (cutoff: 50 ACLRs/surgeon, 500 ACLRs/clinic) and annual volume (cutoff: 29 ACLRs/year/surgeon, 56 ACLRs/year/clinic). The thresholds of minimal important change (MIC), Patient Acceptable Symptom State (PASS), and treatment failure (TF) relative to the Knee injury and Osteoarthritis Outcome Score (KOOS) and KOOS4 (mean score of the KOOS Pain, Symptoms, Sports/Rec, and QoL subscales) were applied. Adjusted multivariable logistic regression was performed to assess variables influencing the MIC, PASS, or TF of the KOOS and KOOS4. Adjusted Cox regression analysis was conducted to determine the hazard ratio of subsequent ACLR.

Results

Of 35,371 patients, 16,317 had 2-year follow-up outcome data and were included. Patients who underwent primary ACLR by high-volume surgeons had significantly higher MIC and PASS rates and lower TF rates when compared with patients who underwent the procedure by low-volume surgeons: MICKOOS4: 70.6% vs 66.3%; PASSKOOS4: 46.0% versus 38.3%; and TFKOOS4: 8.7% versus 11.8% (all P < .02). Significantly decreased odds of achieving MICKOOS4 (OR, 0.74; 95% CI, 0.62-0.88) and PASSKOOS4 (OR, 0.71; 95% CI, 0.60-0.84) were found for ACLRs performed by low-volume surgeons. Clinic volume did not influence the odds of reaching MIC, PASS, or TF. Overall, 804 patients (2.3%) underwent subsequent ACLR at <2 years, with significantly higher revision rates among patients operated on at high-volume clinics (2.5% vs 1.7%; P < .001). However, in the adjusted Cox regression, surgeon/clinic volume had no influence on subsequent ACLR rates. High-volume surgeons/clinics had decreased time to surgery, operating time, perioperative complication rates, and use of thromboprophylaxis and nonroutine antibiotics (P < .001).

Conclusion

Patients who underwent primary ACLR by high-volume surgeons experienced increased improvement and satisfaction regarding subjective knee function. Factors other than surgical volume influenced subsequent surgery rates. Patients might benefit from undergoing primary ACLR by high-volume providers.

Outcomes of RigidFix Cross Pin Fixation in Femoral and Tibial Tunnel for Anterior Cruciate Ligament Reconstruction

OBJECTIVES

There is no clear consensus so far on which fixation method is most favorable for the tibial tunnel in anterior cruciate ligament reconstruction (ACLR). The purpose of this paper is to investigate the outcome of RigidFix cross pins fixation in the tibial tunnel and to explore the advantages of RigidFix applied both in the femoral and tibial tunnel with hamstring tendon graft in anterior cruciate ligament reconstruction.

METHODS

This retrospective study included 53 patients (male/female, 45/8) who underwent anterior cruciate ligament reconstruction using autologous hamstring tendons between January 2013 and December 2017 at our institute. The participants in group A (n = 36) received anterior cruciate ligament reconstruction with RigidFix cross pins fixation in both femoral and tibial tunnels, while those in group B (n = 17) with RigidFix cross pins fixation in the femoral tunnel and Interference screw fixation in the tibial tunnel. The visual analogue scale (VAS) score, International Knee Documentation Committee subjective knee form 2000 (IKDC2000) score, Lysholm knee scoring scale, Tegner activity score and the side-to-side difference were compared at 2 and 5 years postoperatively. The graft diameter, number of strands in graft and the average diameter of each strand were also compared between the two groups. The categorical parameters were analyzed by chi-square test and the continuous variables conforming to a normal distribution were analyzed by Student's t-test.

RESULTS

At 2 years postoperation, the VAS score (1.61 ± 0.55), side-to-side difference (1.50 ± 0.58) in group A were significantly lower than that in group B, and the IKDC2000 score (88.81 ± 3.88), Tegner activity score (6.14 ± 0.60) in group A were significantly higher than that in group B. At 5 years postoperation, the VAS score (1.64 ± 0.68), side-to-side difference (1.73 ± 0.63) in group A were significantly lower than that in group B, and the IKDC2000 score (89.09 ± 3.85), Tegner activity score (6.58 ± 0.94) in group A were slso significantly higher than that in group B. There was statistical difference in the change of the side-to-side difference between the two groups (group A vs. B, 0.22 ± 0.08 vs. 0.34 ± 0.11, p < 0.001). There were also statistical differences in the graft diameter (group A vs. B, 7.83 ± 0.74 vs. 7.41 ± 0.51, p = 0,038), number of strands in graft (5.67 ± 0.72 vs. 4.00 ± 0.00, p < 0.001) and the average diameter of each strand (1.41 ± 0.22 vs. 1.85 ± 0.13, p < 0.001) between the two groups.

CONCLUSION

RigidFix cross pins fixation in the tibial tunnel for anterior cruciate ligament reconstruction can achieve better 5-year results when compared with the interference screw, and the hamstring tendon can be folded into a thicker graft when RigidFix cross pins were applied in both femoral and tibial tunnels.

The Delaware-Oslo ACL Cohort treatment algorithm yields superior outcomes to usual care 9-12 years after anterior cruciate ligament reconstruction

PURPOSE

Patient-reported outcomes were compared between participants who followed the treatment algorithm of the Delaware-Oslo ACL Cohort, consisting of progressive preoperative and postoperative rehabilitation, patient education, clinical testing and shared decision-making about treatment choice, and those who followed usual care 9-12 years after anterior cruciate ligament reconstruction (ACLR).

METHODS

Participants with primary ACLR were included from the Norwegian arm of the Delaware-Oslo ACL Cohort and the Norwegian Knee Ligament Registry (usual care). The Knee Injury and Osteoarthritis Outcome Score (KOOS) subscale scores and the International Knee Documentation Committee-Subjective Knee Form (IKDC-SKF) scores were compared. KOOS scores for the usual care group were converted to IKDC-SKF scores with recently published validated crosswalk. The percentages of participants with scores above predefined thresholds for patient acceptable symptom state (PASS) were also calculated.

RESULTS

Eighty of 100 (80%) participants from the Delaware-Oslo ACL Cohort and 1588 of 3248 (49%) from the usual care group participated in the follow-up. Participants from the Delaware-Oslo ACL Cohort had higher KOOS subscale (p < 0.001) and IKDC-SKF scores (p < 0.001), and a higher percentage reached PASS (84%-96% vs. 62%-76%, p ≤ 0.002) for KOOS Pain, symptoms, activities of daily living and sports compared to the usual care group. No significant differences were found for KOOS quality of life scores (not significant [n.s.]) or PASS percentages (80% vs. 74%, n.s.).

CONCLUSION

Participants with ACLR who followed the Delaware-Oslo ACL Cohort treatment algorithm had reduced knee symptoms, superior function and higher percentages of satisfactory outcomes than participants who followed usual care.

LEVEL OF EVIDENCE

Level II.

Injury risk functions for the four primary knee ligaments

The purpose of this study was to develop injury risk functions (IRFs) for the anterior and posterior cruciate ligaments (ACL and PCL, respectively) and the medial and lateral collateral ligaments (MCL and LCL, respectively) in the knee joint. The IRFs were based on post-mortem human subjects (PMHSs). Available specimen-specific failure strains were supplemented with statistically generated failure strains (virtual values) to accommodate for unprovided detailed experimental data in the literature. The virtual values were derived from the reported mean and standard deviation in the experimental studies. All virtual and specimen-specific values were thereafter categorized into groups of static and dynamic rates, respectively, and tested for the best fitting theoretical distribution to derive a ligament-specific IRF. A total of 10 IRFs were derived (three for ACL, two for PCL, two for MCL, and three for LCL). ACL, MCL, and LCL received IRFs in both dynamic and static tensile rates, while a sufficient dataset was achieved only for dynamic rates of the PCL. The log-logistic and Weibull distributions had the best fit (p-values: >0.9, RMSE: 2.3%-4.7%) to the empirical datasets for all the ligaments. These IRFs are, to the best of the authors' knowledge, the first attempt to generate injury prediction tools based on PMHS data for the four knee ligaments. The study has summarized all the relevant literature on PHMS experimental tensile tests on the knee ligaments and utilized the available empirical data to create the IRFs. Future improvements require upcoming experiments to provide comparable testing and strain measurements. Furthermore, emphasis on a clear definition of failure and transparent reporting of each specimen-specific result is necessary.

The use of slice encoding for metal artifact correction (SEMAC) sequencing improves the diagnostic evaluation of graft integrity following anterior cruciate ligament reconstruction

OBJECTIVES

To determine whether magnetic resonance imaging (MRI) with metal artifact reduction sequencing is superior to conventional knee MRI in the evaluation of an injured anterior cruciate ligament (ACL) graft, where visualisation on conventional MRI can be limited by the metal artifact from fixation devices.

METHODS

Eighteen patients underwent conventional MRI sequence (proton density fat saturated [PDFS]) and two types of metal artifact reduction sequencing MRI (WARP, slice encoding for metal artifact correction (SEMAC); Siemens) following a secondary injury to their ACL reconstructed knee. Six raters with experience in knee MRI evaluation reviewed sagittal PDFS, WARP, and SEMAC sequences, providing semi-quantitative grades for visualisation and diagnostic confidence assessing the ACL, posterior cruciate ligament , menisci, tibial and femoral tunnel margins, and articular cartilage. Intra-class correlation coefficients for inter-rater reliability were evaluated. The 6-rater mean scores for the visualisation and diagnostic confidence derived from each sequence were compared using the Friedman test for multiple paired samples.

RESULTS

No statistically significant difference in the ACL visualisation among the sequences was found (p ​= ​0.193). Further, a subgroup analysis was performed in cases evaluated as "moderately blurry" or "indistinct ACL visualisation" on PDFS (58% of cases). SEMAC significantly improved diagnostic confidence in ACL visualisation (p ​= ​0.041) and ACL graft rupture (p ​= ​0.044) compared to PDFS. There was no statistically significant difference in the inter-observer reliability between sequences. The WARP sequence added 2.84 ​± ​0.69 ​min, while SEMAC added 2.95 ​± ​0.40 ​min to the standard knee MRI scan time.

CONCLUSION

use of the SEMAC metal reduction sequence significantly improved diagnostic accuracy and confidence in the detection of ACL graft rupture in cases where the ACL was moderately blurry or indistinct on the PDFS sequence. This sequence should be considered as an adjunct to conventional PDFS in cases where graft visualisation is limited by the metal artifact from fixation devices.

LEVEL OF EVIDENCE

III.

Histopathological Analysis of the Degree of Tendinosis in Failed Anterior Cruciate Ligament Grafts

INTRODUCTION

After reconstruction of the anterior cruciate ligament, the modification processes in the transplanted tendon tissue directly influence the biomechanical properties of the knee. The histopathological alterations in failed grafts have hardly been studied.

OBJECTIVE

Our study focused on examining the presence and extent of tendinosis (low or high grade) in the tendon tissue of failed anterior cruciate ligament reconstructions. We considered its relationship to the type of transplant, the symptoms, the arthroscopic appearance, the mode of trauma, and the timing of the failure.

MATERIALS AND METHODS

The tendon tissue of failed anterior cruciate ligament reconstructions in 30 patients was gathered during revision surgery and its histopathology was analysed for the occurrence of structural alterations. The classification of the tendinosis as low or high grade was semiquantitative based on five qualities. We used a standardised questionnaire to collect patient data and we used the Marburg Arthroscopy Score for the intraoperative evaluation of the graft.

RESULTS

We found histological vitality and, except for two samples, structural alterations consistent with tendinosis, predominantly high grade, in all failed anterior cruciate ligament grafts. No direct link could be proved between the degree of tendinosis and the type of graft used, the symptoms (except for instability) or the timing of the graft failure, the mode of trauma, or the arthroscopic appearance of the failed plasty. However, the accumulation of high-grade tendinosis in patients with hamstring tendons, subjective instability, and graft failure between 1 to 5 years postoperatively was noteworthy.

CONCLUSION

Structural alterations consistent with tendinosis could be detected, with different expressions, in the vital tendon tissue of anterior cruciate ligament reconstructions. This indicates that the graft is subject to repetitive microtrauma. However, it is still unclear how tendinosis influences the failure of anterior cruciate ligament reconstructions.

Tourniquet-less arthroscopic anterior cruciate ligament reconstruction: a technical guide & narrative review of the evidence

Arthroscopic anterior cruciate ligament reconstruction (ACLR) is often performed with the use of a thigh tourniquet. Surgeons believe this helps improve visualisation and reduce operative time. However, tourniquet use has been associated with many complications including increased pain, neurovascular injury, venous thromboembolism, haematoma formation, and others. In this article, we describe a method allowing comparable arthroscopic visualisation to be achieved without the aid of a tourniquet for ACLR procedures. The literature evidence relating to this technique as well as tourniquet use for ACLR is also reviewed. Tourniquet-less ACLR can be achieved through the combined application of hypotensive anaesthesia, intravenous tranexamic acid, and use of adrenaline-supplemented irrigation fluid and local anaesthetic. Performing ACLR without a tourniquet avoids the risks associated with its use and reduces the severity of post-operative haemarthrosis which may contribute to the patient's pain and limit their ability to perform their rehabilitation exercises.

Graft choices for paediatric anterior cruciate ligament reconstruction: State of the art

The paediatric population is at particularly high risk for anterior cruciate ligament (ACL) injuries due to high rates of sports participation. Other risk factors for ACL injuries in children include but are not limited to being female, generalised ligamentous laxity, a high body mass index (BMI), and poor neuromuscular control. ACL reconstruction (ACLR) is commonly done to treat ACL injuries and allow for return to sports and daily activities. ACL repair is another option with ongoing techniques being developed. The high rates of graft failure in children reported in recent publications on ACL repair are very concerning. Special consideration must be taken in ACLR in the skeletally immature patient due to the risk of growth-related complications, such as limb deformity or growth arrest, that can arise from drilling across or disrupting the physis. Graft choices for paediatric ACLR include iliotibial band (ITB) over the top and over the front, hamstring autograft, bone patellar tendon bone (BTB) autograft, quadriceps tendon autograft, and allograft. Factors for each graft choice to consider include graft size, graft failure rates, donor site morbidity, requirement for bony tunnels, the post-op rehabilitation process, and return to sport outcomes. Each graft has its benefits and disadvantages for the individual patient, depending on age, skeletal maturity, and goals for recovery. Lateral extra-articular tenodesis (LET) is another option to consider with paediatric ACLR because LET has been shown to decrease the re-rupture rate in adult ACLR. After surgery, patient follow-up until at least the growth plates are closed is important. This article aims to provide an overview and comparison of the various graft types to aid in the graft choice decision making process for paediatric ACLR.

The anterior cruciate ligament injury severity scale (ACLISS) is an effective tool to document and categorize the magnitude of associated tissue damage in knees after primary ACL injury and reconstruction

PURPOSE

To develop a tool allowing to classify the magnitude of structural tissue damage occurring in ACL injured knees. The proposed ACL Injury Severity Scale (ACLISS) would provide an easy description and categorization of the wide spectrum of injuries in patients undergoing primary ACL reconstruction, reaching from isolated ACL tears to ACL injuries with a complex association of combined structural damage.

METHODS

A stepwise approach was used to develop the ACLISS. The eligibility of each item was based on a literature search and a consensus between the authors after considering the diagnostic modalities and clinical importance of associated injuries to the menisci, subchondral bone, articular cartilage or collateral ligaments. Then, a retrospective analysis of associated injuries was performed in 100 patients who underwent a primary ACL reconstruction (ACLR) by a single surgeon. This was based on acute preoperative MRI (within 8 weeks after injury) as well as intraoperative arthroscopic findings. Depending on their prevalence, the number of selected items was reduced. Finally, an analysis of the overall scale distribution was performed to classify the patients according to different injury profiles.

RESULTS

A final scoring system of 12 points was developed (12 = highest severity). Six points were attributed to the medial and lateral tibiofemoral compartment respectively. The amount of associated injuries increased with ACLISS grading. The median scale value was 4.5 (lower quartile 3.0; higher quartile 7.0). Based on these quartiles, a score < 4 was considered to be an injury of mild severity (grade I), a score between ≥ 4 and ≤ 7 was defined as moderately severe (grade II) and a score > 7 displayed the most severe cases of ACL injuries (grade III). The knees were graded ACLISS I in 35%, ACLISS II in 49% and ACLISS III in 16% of patients. Overall, damage to the lateral tibiofemoral compartment was predominant (p < 0.01), but a proportional increase of tissue damage could be observed in the medial tibiofemoral compartment with the severity of ACLISS grading (p < 0.01).

CONCLUSIONS

The ACLISS allowed to easily and rapidly identify different injury severity profiles in patients who underwent primary ACLR. Injury severity was associated with an increased involvement of the medial tibiofemoral compartment. The ACLISS is convenient to use in daily clinical practice and represents a feasible grading and documentation tool for a reproducible comparison of clinical data in ACL injured patients.

LEVEL OF EVIDENCE

Level III.

International cooperation needed to improve national anterior cruciate ligament registries

PURPOSE

The aim of this study is to illustrate an overview of the registries currently operative in many countries to support the introduction of new prospective registries in other countries.

METHODS

The authors carried out a systematic web research in July 2021 to identify national ACL registries' annual reports and scientific literature on national ACL registries. The latest annual public registry reports were collected and analyzed in this study.

RESULTS

There are currently established national ACL registries in Norway, Denmark, Sweden, Luxembourg, New Zealand, the United Kingdom (UK), and the Kaiser Permanente National Anterior Cruciate Ligament Reconstruction Registry in the United States (US). Some differences can be found among the various registries due to the local healthcare system structure, data management rules, and general national laws.

CONCLUSION

It is possible to develop accessible, cost-effective and entirely web-based ACL registries-as demonstrated by the Danish and Swedish registries-respecting the national legislation of different countries. This study supports the introduction of new ACL prospective registries in other countries to obtain valuable information for implementing daily clinical practice.

LEVEL OF EVIDENCE

IV.

Surgeon's experience, sports participation and a concomitant MCL injury increase the use of patellar and quadriceps tendon grafts in primary ACL reconstruction: a nationwide registry study of 39,964 surgeries

PURPOSE

To investigate the influence of surgeon-related factors and clinic routines on autograft choice in primary anterior cruciate ligament reconstruction (ACLR).

METHODS

Data from the Swedish National Knee Ligament Registry (SNKLR), 2008-2019, were used to study autograft choice (hamstring; HT, patellar; PT, or quadriceps tendon; QT) in primary ACLR. Patient/injury characteristics (sex, age at surgery, activity at time of injury and associated injuries) and surgeon-/clinic-related factors (operating volume, caseload and graft type use) were analyzed. Surgeon/clinic volume was divided into tertiles (low-, mid- and high-volume categories). Multivariable logistic regression was performed to assess variables influencing autograft choice in 2015-2019, presented as the odds ratio (OR) with a 95% confidence interval (CI).

RESULTS

39,964 primary ACLRs performed by 299 knee surgeons in 91 clinics were included. Most patients received HT (93.7%), followed by PT (4.2%) and QT (2.1%) grafts. Patients were mostly operated on by high-volume (> 28 ACLRs/year) surgeons (68.1%), surgeons with a caseload of ≥ 50 ACLRs (85.1%) and surgeons with the ability to use ≥ two autograft types (85.9%) (all p < 0.001). Most patients underwent ACLR at high-volume (> 55 ACLRs/year) clinics (72.2%) and at clinics capable of using ≥ two autograft types (93.1%) (both p < 0.001). Significantly increased odds of receiving PT/QT autografts were found for ACLR by surgeons with a caseload of ≥ 50 ACLRs (OR 1.41, 95% CI 1.11-1.79), but also for injury during handball (OR 1.31, 95% CI 1.02-1.67), various other pivoting sports (basketball, hockey, rugby and American football) (OR 1.59, 95% CI 1.24-2.03) and a concomitant medial collateral ligament (MCL) injury (OR 4.93, 95% CI 4.18-5.80). In contrast, female sex (OR 0.87, 95% CI 0.77-0.97), injury during floorball (OR 0.71, 95% CI 0.55-0.91) and ACLR by mid-volume relative to high-volume surgeons (OR 0.62, 95% CI 0.53-0.73) had significantly reduced odds of receiving PT/QT autografts.

CONCLUSION

An HT autograft was used in the vast majority of cases, but PT/QT autografts were used more frequently by experienced surgeons. Prior research has demonstrated significant differences in autograft characteristics. For this reason, patients might benefit if surgery is performed by more experienced surgeons.

LEVEL OF EVIDENCE

Level III.

Different patient and activity-related characteristics result in different injury profiles for patients with anterior cruciate ligament and posterior cruciate ligament injuries

PURPOSE

To compare patient characteristics including patient sex, age, body mass index (BMI), activities at the time of injury and injury profiles in patients with anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) injuries.

METHODS

Data were obtained from the Swedish National Knee Ligament Registry. Two study groups were created: (1) index ACL reconstruction (ACL group) and (2) index PCL reconstruction (PCL group). Between-group differences were investigated using Fisher's exact test and Fisher's non-parametric permutation test for dichotomous variables and continuous variables, respectively.

RESULTS

Of 39,010 patients, 38,904 were ACL injuries. A larger proportion of patients with combined injuries to the PCL, meniscus and cartilage were female, aged > 25 years and with a BMI of > 35 kg/m² compared with patients with combined injuries to the ACL, meniscus and cartilage. An isolated ACL injury was more commonly found in males, while all other injury profiles of ACL, including combined injuries with meniscus, cartilage and collateral ligament injuries, were more frequently observed in females. The PCL injuries were sustained either during pivoting sports, non-pivoting sports or were traffic-related.

CONCLUSION

Different patient characteristics (BMI, age and sex), and activities at the time of injury (sport- versus traffic-related activities), resulted in distinct injury profiles for the ACL and PCL groups. These findings provide valuable information of the way specific injury patterns of cruciate ligament injuries occur, and subsequently may help clinicians with the diagnostic process of ACL and PCL injuries.

LEVEL OF EVIDENCE

III.

GRAFTS FOR ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION: SYSTEMATIC REVIEW AND META-ANALYSIS

Objective

This study proposes to systematically review the literature and compare data on (1) function, (2) pain, (3) return to sport, and (4) complications after anterior cruciate ligament (ACL) reconstruction with quadriceps tendon autograft (QT) and hamstring tendon autograft (HT).

Methods

In June 2021, a systematic review of the EMBASE, MEDLINE/PubMed, Cochrane Central Register of Controlled Trials, and LILACS databases was performed, based on PRISMA guidelines. The search strategy included the keywords: "Previous Cruciate Ligament Reconstruction," "ACL reconstruction," "quadriceps tendon autograft," "quadriceps graft," "Hamstring-Tendon Autografts." Meta-analyses were performed using Review Manager software (RevMan Web).

Results

There were no significant differences between the two groups regarding function according to Lysholm score (MD 3.01; CI-0.30, 6.33, p = 0.08), the presence of pain (RR 0.89; CI-0.57, 1.39, p = 0.60), and re-rupture (RR 0.60; IC-0.19, 1.88, p = 0.38).

Conclusion

QT and HT autografts show comparatively good results in ACL reconstruction without significant differences regarding function, pain, and rupture after surgical intervention. Level of Evidence II, Systematic Review of Level II Studies.

The SFA datalake platform and anterior cruciate ligament tear registry of the French Society of Arthroscopy (SFA): Rationale, statutes and plans

SFA Datalake is the registry platform of the French Society of Arthroscopy (SFA). It was designed to collect and store data on arthroscopic orthopedic surgery and joint-sparing surgery in French-speaking countries. The anterior cruciate ligament (ACL) tear registry is the first registry to be set up based on SFA Datalake. Registries are intended to enable systematic standardized data collection, and provide information for surgeons to improve clinical practice and results. The ACL tear registry was designed in the light of guidelines, the literature and existing registries. Data are collected prospectively on a secure on-line application accessible via a computer or smartphone. Data collection is organized according to clinical examination results, preoperative findings, and follow-up data based on patient-administered subjective quality of life questionnaires. The pilot committee consists of 5 SFA board members, appointed for 2 years. LEVEL OF EVIDENCE: IV.

Time, graft, sex, geographic location, and isokinetic speed influence the degree of quadriceps weakness after anterior cruciate ligament reconstruction: a systematic review and meta-analysis

PURPOSE

Although quadriceps weakness after ACL reconstruction (ACLR) is well documented, the magnitude of reported weakness varies considerably. Such variation raises the possibility that certain patients may be more susceptible to quadriceps weakness after ACLR. This meta-analysis identified factors explaining between-study variability in quadriceps weakness post-ACLR.

METHODS

Studies between 2010 and 2020 were screened for the following criteria: human subjects, unilateral ACLR, and strength reported both for the ACLR leg and the uninjured or healthy-control leg. 122 studies met the criteria, resulting in 303 and 152 Cohen's d effect sizes (ESs) comparing ACLR legs to uninjured legs (a total of 4135 ACLR subjects) and to healthy controls (a total of 1,507 ACLR subjects vs. 1-193 healthy controls), respectively. Factors (time, graft, sex, activity, mass/height, geographic area, concomitant injury, and type of strength testing) that may affect study ES were examined.

RESULTS

Meta-regressions indicated an association between time post-ACLR and study ESs (P < 0.001) and predicted full recovery (ES = 0) to occur at 54-59 months post-ACLR. When compared to uninjured legs, patients with patellar tendon autografts had greater deficits than studies using hamstring tendon autografts (P = 0.023). When compared to uninjured legs, studies including only males reported greater deficits than studies combining males and females (P = 0.045); whereas when compared to healthy controls, studies combining males and females reported greater deficits than studies with males (P = 0.013). When compared to controls, studies from USA reported greater deficits than studies from Europe (P = 0.003). Increased isokinetic-testing speed was associated with smaller deficits (P ≤ 0.025). Less than 25% of patients achieved a between-limb symmetry in quadriceps strength > 90% between 6 and 12 months post-ACLR.

CONCLUSION

Time post-surgery, graft, sex, geographic location, and isokinetic speed influenced the magnitude of post-ACLR quadriceps weakness. Patients with patellar tendon autografts demonstrated greater between-limb asymmetry in quadriceps strength, while female strength deficits were underestimated to a greater extent. A slower isokinetic speed provided a more sensitive assessment of quadriceps strength post-ACLR. The overwhelming majority of patients were returning to sport with significantly impaired quadriceps strength.

LEVEL OF EVIDENCE

III.

Knee registries: state of the art

Sports injuries, trauma and the globally ageing and obese population require increasing levels of knee surgery. Shared decision making has replaced the paternalistic approach to patient management. Evidence-based medicine underpins surgical treatment strategies, from consenting an individual patient to national healthcare system design. The evolution of successful knee-related registries starting from specific arthroplasty registries has given rise to ligament reconstruction, osteotomy and cartilage surgery registries developing as platforms for surgical outcome data collection. Stakeholders include surgeons and their patients, researchers, healthcare systems, as well as the funding insurers and governments. Lately, implant manufacturers have also been mandated to perform postmarket surveillance with some hoping to base that on registry data. Aiming to assess the current status of knee-related registries, we performed a comprehensive literature and web search, which yielded 23 arthroplasty, 8 ligament, 4 osteotomy and 3 articular cartilage registries. Registries were evaluated for their scope, measured variables, impact and limitations. Registries have many advantages as they aim to increase awareness of outcomes; identify trends in practice over time, early failing implants, outlier surgeon or institution performance; and assist postmarketing surveillance. International collaborations have highlighted variations in practice. The limitations of registries are discussed in detail. Inconsistencies are found in collected data and measured variables. Potential measurement and selection biases are outlined. Without mandated data collection and with apparent issues such as unverified patient reporting of complications, registries are not designed to replace adverse event recording in place of a proper safety and efficacy study, as demanded by regulators. Registry 'big data' can provide evidence of associations of problems. However, registries cannot provide evidence of causation. Hence, without careful consideration of the data and its limitations, registry data are at risk of incorrectly drawn conclusions and the potential of misuse of the results. That must be guarded against. Looking at the future, registry operators benefit from a collective experience of running registries as they mature, allowing for improvements across specialties. Large-scale registries are not only of merit, improving with stakeholder acceptance, but also are critical in furthering our understanding of our patients' outcomes. In doing so, they are a critical element for our future scientific discourse.

Acute and subacute anterior cruciate ligament reconstructions are associated with a higher risk of revision and reoperation

PURPOSE

(1) Report concomitant cartilage and meniscal injury at the time of anterior cruciate ligament reconstruction (ACLR), (2) evaluate the risk of aseptic revision ACLR during follow-up, and (3) evaluate the risk of aseptic ipsilateral reoperation during follow-up.

METHODS

Using a United States integrated healthcare system's ACLR registry, patients who underwent primary isolated ACLR were identified (2010-2018). Multivariable Cox proportional-hazards regression was used to evaluate the risk of aseptic revision, with a secondary outcome evaluating ipsilateral aseptic reoperation. Outcomes were evaluated by time from injury to ACLR: acute (< 3 weeks), subacute (3 weeks-3 months), delayed (3-9 months), and chronic (≥ 9 months).

RESULTS

The final sample included 270 acute (< 3 weeks), 5971 subacute (3 weeks-3 months), 5959 delayed (3-9 months), and 3595 chronic (≥ 9 months) ACLR. Medial meniscus [55.4% (1990/3595 chronic) vs 38.9% (105/270 acute)] and chondral injuries [40.0% (1437/3595 chronic) vs 24.8% (67/270 acute)] at the time of ACLR were more common in the chronic versus acute groups. The crude 6-year revision rate was 12.9% for acute ACLR, 7.0% for subacute, 5.1% for delayed, and 4.4% for chronic ACLR; reoperation rates a 6-year follow-up was 15.0% for acute ACLR, 9.6% for subacute, 6.4% for delayed, and 8.1% for chronic ACLR. After adjustment for covariates, acute and subacute ACLR had higher risks for aseptic revision (acute HR 1.70, 95% CI 1.07-2.72, p = 0.026; subacute HR 1.25, 95% CI 1.01-1.55, p = 0.040) and aseptic reoperation (acute HR 2.04, 95% CI 1.43-2.91, p < 0.001; subacute HR 1.31, 95% CI 1.11-1.54, p = 0.002) when compared to chronic ACLR.

CONCLUSIONS

In this cohort study, while more meniscal and chondral injuries were reported for ACLR performed ≥ 9 months after the date of injury, a lower risk of revision and reoperation was observed following chronic ACLR relative to patients undergoing surgery in acute or subacute fashions.

Management of the Failed First Revision ACL Reconstruction: Clinical Outcomes of Nonsurgical Management Versus Second Revision ACL Reconstruction From the SANTI Group

BACKGROUND

The optimum management strategy after failure of revision anterior cruciate ligament reconstruction (RACLR) is not clearly defined. The literature evaluating differences in outcomes between surgical and nonsurgical management is sparse.

PURPOSE/HYPOTHESIS

The purpose was to evaluate the outcomes of surgical versus nonsurgical management of failed first RACLR. It was hypothesized that the long-term clinical outcomes of second RACLR would be superior with respect to knee stability, return to sport, and patient-reported outcome measures when compared with nonsurgical treatment.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients who experienced failure of first RACLR were evaluated. All participants followed the same rehabilitation protocol regardless of whether they underwent nonsurgical treatment or a second RACLR. Follow-up comprised regular clinical review and a standardized telephone interview at the end of the study period. Patient-reported outcome measures were recorded at the final follow-up.

RESULTS

A total of 41 patients with a mean follow-up of 104 ± 52.7 months (range, 40-140 months) were evaluated. Of these, 31 underwent a second RACLR, and 10 patients chose nonsurgical treatment. There was a high rate of return to sport in both groups, but patients undergoing second RACLR had significantly better Tegner (6.35 vs 4.8; P = .012), Lysholm (88.5 vs 78.3; P = .0353), Knee injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (72.6 vs 56.3; P = .0490), and KOOS Sport and Recreation scores (81.4 vs 62.5; P = .0033). Significantly more patients undergoing second RACLR achieved the Patient Acceptable Symptom State for KOOS Sport and Recreation than those who underwent nonsurgical management (74.2% vs 30%; P = .015). The most important predictor of failure to achieve a good/excellent Lysholm score in multivariate analysis was nonsurgical management (P = .0095).

CONCLUSION

Both second RACLR and nonsurgical management of failed first RACLR were associated with high rates of return to sport. However, second RACLR was associated with significantly better functional outcome scores with respect to Tegner, Lysholm, KOOS Quality of Life, and KOOS Sport and Recreation scores compared to nonsurgical management. In addition, nonsurgical treatment was the only significant predictor of failure to achieve a good/excellent Lysholm score at the final follow-up, and this was likely a function of inferior knee stability in that group.

Effects of remnant preservation in anterior cruciate ligament reconstruction: A systematic review and meta-analysis

Background

Compared with standard anterior cruciate ligament (ACL) reconstruction, it is controversial whether anterior cruciate ligament reconstruction (ACLR) with remnant preservation can lead to better clinical outcomes. We conducted a systematic study and meta-analysis to assess the differences in clinical efficacy between the two.

Method

We searched for clinical randomized controlled studies and cohort studies included in the Cochrane library, PubMed, and Embase from March 2012 to March 2022 in English. The included studies were ACLR with or without remant preservation, and the data were extracted and the quality of the included studies was assessed by two authors, respectively. Revman 5.4 was used for statistical analysis and conclusions were presented.

Result

Ten articles containing a total of 777 patients were finally included. There was no significant difference in postoperative Lachman test [OR = 1.66, 95%CI (0.79, 3.49), P = 0.18 > 0.05], Tegner score [SMD = −0.13, 95%CI (−0.47, 0.22), P = 0.46 > 0.05], synovial coverage rate by second-look arthroscopy [OR = 1.55, 95%CI (0.66, 3.65), P = 0.32 > 0.05], the rate of cyclops lesion [OR = 3.92, 95%CI (0.53, 29.29), P = 0.18 > 0.05], joint range of motion [SMD = 0.27, 95%CI (−0.13, 0.68), P = 0.19 > 0.05] and re-injury rate [OR = 0.57, 95%CI (0.18, 1.74), P = 0.32 > 0.05] between the two groups. There were statistically significant differences in postoperative Lysholm score [SMD = 0.98, 95% CI (0.32, 1.64), P = 0.004 < 0.05], International Knee Documantation Committee grade (IKDC grade) [OR = 2.19, 95%CI (1.03, 4.65), P = 0.04 < 0.05], Pivot shift test [OR = 1.71, 95%CI (1.06, 2.77), P = 0.03 < 0.05], KT1000/2000 arthrometer side-to-side difference [SMD = −0.22, 95%CI (−0.42, −0.03), P = 0.02 < 0.05], operation time [SMD = 11.69, 95%CI (8.85, 14.54), P = 0.00001 < 0.05] and degree of tibial tunnel enlargement [SMD = −0.66, 95%CI (−1.08, −0.23), P = 0.002 < 0.05].

Conclusion

This meta-analysis concluded that remnant preservation significantly had better results in terms of patient functional score (Lysholm, IKDC), knee stability (Pivot shift test, postoperative side-to-side anterior laxity) and tibial tunnel enlargement. In terms of complications (incidence of Cyclops lesions, range of motion, re-injury rate), no significant differences were seen between the two groups. Although many studies concluded that remnant preservation could bring better synovial coverage, this meta-analysis indicated that there is insufficient evidence to support it, possibly due to different remnant preservation procedures.The potential risks associated with longer operation times are also worth considering.

Delayed Surgery, Low Presurgery Activity, and Poor Preoperative IKDC Scores Are Correlated with Lower Rates of Return to Sports after ACL Reconstruction in an Asian Population

There is limited literature regarding the early postsurgical outcomes of anterior cruciate ligament (ACL) reconstruction in Asian populations, particularly in the rates of return to sports. We aimed to quantify early clinical outcomes for ACL reconstruction, determine the predictive value of surgeon- and patient-reported outcomes on the rate of return to sports in the early postoperative period, and identify factors predictive of return to sports. We analyzed the data of 55 patients who underwent ACL reconstruction at our tertiary medical center from 2015 to 2016. All patients underwent transportal ACL reconstruction and a standardized post-ACL reconstruction rehabilitation protocol. Patients with concurrent meniscal injury and repair were included. Patients were evaluated at the 3-month, 6-month, 1-year, and 2-year postoperative periods. Surgeon- and patient-reported outcome scores were collected at each follow-up through a systematic questionnaire designed to determine the patient's level of return to sport and reasons for not returning. Surgeon- and patient-reported outcome measures improved significantly over the 2-year postoperative period (p < 0.001). Overall rate of return to sports was 58.2%. The International Knee Documentation Committee (IKDC) subjective (p = 0.02), symptomatic (p = 0.001), composite (p = 0.005), Tegner (p < 0.001) and Lysholm (p = 0.049) scores at 2-year follow-up were significantly worse in patients who failed to return to sports. Earliest difference in scores manifested at 3-month postsurgery (p = 0.011). IKDC grade-D patients were 18.1 times less likely to return to sports (p = 0.035). Delayed surgery (p = 0.01) and presurgery inactivity (p = 0.023) were negatively predictive of return to sports. The rate of return to sport is consistent with the literature analyzing other ethnic populations. Both surgeon- and patient-reported outcome scores at 2-year postsurgery exhibited significant differences between those who did and did not return to sports. Patients should be advised to seek surgical treatment as soon as possible and stay active preoperatively to maximize return to sports.

Scoping Review on ACL Surgery and Registry Data

Purpose of Review

To present an overview of registry-based anterior cruciate ligament (ACL) research, as well as provide insight into the future of ACL registries.

Recent Findings

During the past decades, the ACL registries have had an important role in increasing our understanding of patients with ACL injuries and their treatment. The registry data has deepened our understanding of factors that have been associated with an increased risk of sustaining an ACL injury and for evaluation of treatment factors and their impact on patient-related outcomes. Recently, registry-based ACL research using artificial intelligence (AI) and machine learning (ML) has shown potential to create clinical decision-making tools and analyzing outcomes. Thus, standardization of collected data between the registries is needed to facilitate the further collaboration between registries and to facilitate the interpretation of results and subsequently improve the possibilities for implementation of AI and ML in the registry-based research.

Summary

Several studies have been based on the current ACL registries providing an insight into the epidemiology of ACL injuries as well as outcomes following ACL reconstruction. However, the current ACL registries are facing future challenges, and thus, new methods and techniques are needed to ensure further good quality and clinical applicability of study findings based on ACL registry data.

Association Between Anteromedial Portal Versus Tibial Tunnel Drilling and Meniscal Reoperation Risk Following Anterior Cruciate Ligament Reconstruction: A Cohort Study

BACKGROUND

Anterior cruciate ligament reconstruction (ACLR) provides functional stability to an injured knee. While multiple techniques can be used to drill the femoral tunnel during ACLR, a single technique has yet to be proven as clinically superior. One marker of postoperative functional stability is subsequent meniscal tears; a lower risk of subsequent meniscal surgery could be expected with improved knee stability.

PURPOSE

To determine if there is a meniscal protective effect when using an anteromedial portal (AMP) femoral tunnel drilling technique versus transtibial (TT) drilling.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Data from Kaiser Permanente's ACLR registry were used to identify patients who had a primary isolated ACLR between 2009 and 2018; those with previous surgery in the index knee and meniscal pathology at the time of ACLR were excluded. The exposure of interest was TT (n = 2711) versus AMP (n = 5172) drilling. Multivariable Cox proportional hazard regression was used to evaluate the risk of a subsequent ipsilateral meniscal reoperation with adjustment for age, sex, femoral fixation, and graft choice. We observed a shift in surgeon practice from the TT to AMP over the study time frame; therefore, the relationship between technique and surgeon experience on meniscal reoperation was evaluated using an interaction term in the model.

RESULTS

At the 9-year follow-up, the crude cumulative meniscal reoperation probability for AMP procedures was 7.76%, while for TT it was 5.88%. After adjustment for covariates, we observed a higher risk for meniscal reoperation with AMP compared with TT (hazard ratio [HR], 1.53; 95% CI, 1.05-2.23). When stratifying by surgeon experience, this adverse association was observed for patients who had their procedure performed by surgeons with less AMP experience (no previous AMP ACLR: HR, 1.26; 95% CI, 0.84-1.91) while a protective association was observed for patients who had their procedure with more experienced surgeons (40 previous AMP ACLRs: HR, 0.34; 95% CI, 0.13-0.92).

CONCLUSION

Drilling the femoral tunnel via the AMP was associated with a higher risk of subsequent meniscal surgery compared with TT drilling. However, when AMP drilling was used by surgeons experienced with the technique, a meniscal protective effect was observed.

Epidemiological profile of anterior cruciate ligament injuries in a tertiary referral trauma center of Nepal

Background

Sports related injuries are the leading cause of Anterior Cruciate Ligament (ACL) tear in the Western world. Although professional and recreational sporting activities are increasing in Nepal, they are not as common and prevalent in comparison to western world. In contrast, Road Traffic Accident (RTA) is a very common cause of knee injuries in Nepal. Although there are some studies from Nepal mentioning Road Traffic Accidents (RTAs) as the most common cause of ACL injury, no specific studies have primarily investigated the epidemiological and demographic profile of ACL injured patients from this region. we aimed to understand the epidemiological and demographic profile of ACL injured patients and evaluate the mode of injury in a tertiary referral trauma center of Nepal.

Methods

This was a retrospective descriptive study of a hospital cohort conducted from February 2018 to January 2020. Electronic details were retrieved, telephone interviews conducted and data analysis was done using descriptive analysis on the patients from the fore mentioned dates to complete demographic and epidemiological information.

Results

A total of 237 patients were enrolled in this study. Among these, 120 patients (50.6%) fell into the age group of 15–30 years with a male to female ratio of 2.7:1. A RTA was the most common cause of ACL injury (38.8%), followed by sports-related injuries in 33.3% and falls in 16.5% of patients. The most common mode of RTA was a two-wheeler accident, and football was the most common sport causing ACL injuries. Sports injury was more common in patients below 30 years of age (OR = 3.5, 95% CI [2.2, 5.7]), whereas RTA was more common in patients above 30 years of age. Sports was the cause of ACL injury in 55.5% of students and RTAs was the commonest cause of ACL injury in office workers.

Conclusion

Overall males were more frequently injured than females. Road traffic accidents were the most common cause of ACL injury in our subset of patients. Two-wheeler riders were the most commonly injured patients. Sport was the commonest cause of ACL injury in patients below 30 years, and RTA was common in patients above 30 years of age. Sports were the commonest cause of ACL injury in students, while RTA was the most common cause in office workers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05551-y.

Low annual hospital volume of anterior cruciate ligament reconstruction is not associated with higher revision rates

PURPOSE

Surgery performed in low-volume centres has been associated with longer operating time, longer hospital stays, lower functional outcomes, and higher rates of revision surgery, complications and mortality. This has been reported consistently in the arthroplasty literature, but there is a paucity of data regarding the relationship between surgical volume and outcome following anterior cruciate ligament (ACL) reconstruction. The purpose was to compare ACL reconstruction failure rates between hospitals performing different annual surgical volumes.

METHODS

All patients from the Norwegian Knee Ligament Register having primary autograft ACL reconstruction between 2004 and 2016 were included. Hospital volume was divided into quintiles based on the number of ACL reconstructions performed annually, defined arbitrarily as: 1-12 (V1), 13-24 (V2), 25-49 (V3), 50-99 (V4) and ≥ 100 (V5) annual procedures. Kaplan-Meier estimated survival curves and survival percentages were calculated with revision ACL reconstruction as the end point. Secondary outcome measures included (1) mean change in Knee Injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (QoL) and Sport subsections from pre-operative to 5-year follow-up and (2) subjective failure defined as KOOS QoL < 44.

RESULTS

Twenty thousand eight hundred and fifty patients met the inclusion criteria and 1195 (5.7%) underwent subsequent revision ACL reconstruction over the study period. Revision rates were lower in the lower volume hospitals compared with the higher volume hospitals (p < 0.001). There was no clinically significant difference in improvement between pre-operative and 5-year follow-up KOOS scores between hospital volume categories, but a higher proportion of patients having surgery at lower volume hospitals reported a subjective failure. Patients in the lower volume categories (V1-3) were more often male and older compared to the higher volume hospitals (V4-5). Concomitant meniscal injuries and participation in pivoting sports were most common in V5 compared with V1 (p < 0.001). Median operative time decreased as hospital volume increased, ranging from 90 min at V1 hospitals to 56 min at V5 hospitals (p < 0.001).

CONCLUSION

Patients having ACL reconstruction at lower volume hospitals had a lower rate of subsequent revision surgery relative to higher volume hospitals. However, complications occurred more frequently, operative duration was longer, and the number of patients reporting a subjective failure of ACL reconstruction was highest at these lower volume hospitals.

LEVEL OF EVIDENCE

Level III.

Effect of Geometry on the Fixation Strength of Anterior Cruciate Ligament Reconstruction Using BASHTI Technique

The goal of this study is to investigate the effects of tendon and cannulated drill bit diameter on the strength of the bone and site hold tendon inside (BASHTI) fixation technique for an anterior cruciate ligament (ACL) reconstruction. Bovine digital tendons and Sawbones blocks were used to mimic the ACL reconstruction. Mechanical strength of the specimens was measured using a cyclic loading continued by a single cycle pullout load until failure to simulate the real postsurgical loading conditions. Finally, failure modes of specimens and ultimate failure load were recorded. The maximum possible tendon surface strain (i.e., tendon compression [TC]) for tendon diameters of 6, 7, 8, and 9 mm were 0.73, 0.8, 0.7, and 0.65, respectively. Eighty per cent of the specimens with tendon diameter of 6 mm and 20% of specimens with tendon diameter of 7 mm failed on the torn tendon. All samples with larger tendon diameters (i.e., 8 and 9 mm) failed on the fixation slippage. The maximum fixation strength according to the most suitable core bones for 6, 7, 8, and 9 mm tendons were 148 ± 47 N (core 9.5 mm), 258 ± 66 N (core 9.5 mm), 386 ± 128 N (core 8.5 mm), and 348 ± 146 N (core 8.5 mm), respectively. The mode of tendon failure was significantly influenced by the tendon diameter. Also, an increase in TC raised the fixation strength for all tendon diameters; however, tendon over compression decreased the fixation strength for the 8 mm tendon group. Finally, an empirical equation was proposed to predict BASHTI fixation strength.

Higher risk of ACL rupture in amateur football compared to professional football: 5-year results of the 'Anterior cruciate ligament-registry in German football'

PURPOSE

Anterior cruciate ligament (ACL) injuries are a common severe type of football injury at all levels of play. A football-specific ACL registry providing both prospective ACL injury data according to the skill level and risk factors for ACL injury is lacking in the literature.

METHODS

This study is based on the prospective 'ACL registry in German Football' implemented in the 2014-15 season. Professional (1st-3rd league), semi-professional (4th-6th league) and amateur leagues (7th league) were analysed regarding the incidence and risk factors for ACL injuries. Injuries were registered according to the direct reports of the injured players to the study office and double-checked via media analysis. After injury registration, the players received a standardised questionnaire. Data were analysed from the 2014-15 to the 2018-19 football season.

RESULTS

Overall, 958 ACL injuries were registered during the 5-year study period. The incidence of ACL injuries was highest in amateur football (0.074/1000 h football exposure) compared to professional (0.058/1000 h; p < 0.0001) and semi-professional football (0.043/1000 h; p < 0.0001). At all skill levels, match incidence (professional: 0.343; semi-professional: 0.249; amateur: 0.319) was significantly higher than training incidence (professional: 0.015; semi-professional: 0.004; amateur: 0.005). Major risk factors were previous ACL injury (mean: 23.3%), other knee injuries (mean: 19.3%) and move to a higher league (mean: 24.2%).

CONCLUSION

This sports-specific ACL registry provides detailed information on the incidence and risk factors for ACL injuries in football over five years. Risk factors are skill level, match exposure, move to a higher league and previous knee injury. These factors offer potential starting points for screening at-risk players and applying targeted prevention.

LEVEL OF EVIDENCE

II.

Current concepts in graft selection for anterior cruciate ligament reconstruction

Graft selection for anterior cruciate ligament reconstruction (ACLR) is important for optimizing post-operative rehabilitation, facilitating return to full sporting function and reducing the risk of complications.The most commonly used grafts for ACLR include hamstring tendon autografts, bone-patellar tendon-bone autografts, quadriceps tendon autografts, allografts and synthetic grafts.This instructional review explores the existing literature on clinical outcomes with these different graft types for ACLR and provides an evidence-based approach for graft selection in ACLR.The existing evidence on the use of extra-articular tenodesis to provide additional rotational stability during ACLR is also revisited. Cite this article: EFORT Open Rev 2021;6:808-815. DOI: 10.1302/2058-5241.6.210023.

Medial meniscus ramp and lateral meniscus posterior root lesions are present in more than a third of primary and revision ACL reconstructions

PURPOSE

The purpose of this study was (1) to describe the meniscus tear pattern in anterior cruciate ligament (ACL)-injured patients, with a special focus on medial meniscus (MM) ramp lesions and lateral meniscus (LM) root tears and (2) to determine whether patient and injury characteristics were associated with meniscus tear patterns.

METHODS

Data from 358 cases of ACL primary and revision reconstruction surgeries were extracted from a center-based registry. During arthroscopy, the presence of associated meniscus lesions was documented by systematically inspecting the anterior and posterior tibiofemoral compartments. With a special focus on MM ramp lesions and LM root tears, groups of different injury tear patterns were formed. Chi-square tests were used to determine whether these groups differed with respect to various patient and injury characteristics, including gender, previous ipsilateral ACL injuries, the injury's relation to sport, person contact during injury and the type of ACL tear. Median age at surgery and body mass index were compared between groups using the Kruskal-Wallis test. Significance was set at p < 0.05.

RESULTS

Two hundred and thirty-nine ACL injuries (67%) showed additional meniscal injuries, of which 125 (52%) involved the MM ramp and/or the LM root. Ramp lesions were more frequent in males (23% vs 12% in females, p < 0.01), in contact injuries (28% vs 16% in non-contact, p < 0.05) and in complete ACL tears (21% vs 5% in partial, p < 0.05). Combined injuries of the MM ramp and the LM root showed a higher percentage of contact injuries compared to non-contact injuries (10% vs 4%, p < 0.05).

CONCLUSION

Two-thirds of all ACL injuries showed a concomitant meniscus injury, of which half involved the biomechanically relevant, but previously often undiagnosed RLMM or the PRLM. These findings provide evidence that until recently about half of ACL-associated meniscus injuries were not properly identified. Ramp lesions were more frequent in males, contact injuries and in complete ACL tears. These findings stress the need for a systematic assessment and a better understanding of the pathomechanism of these specific injuries which may have an important impact on knee biomechanics and the outcome of ACL reconstruction.

LEVEL OF EVIDENCE

III.

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.

Graft Failure, Revision ACLR, and Reoperation Rates After ACLR With Quadriceps Tendon Versus Hamstring Tendon Autografts: A Registry Study With Review of 475 Patients

BACKGROUND

It has been indicated that anterior cruciate ligament reconstruction (ACLR) with a quadriceps tendon (QT) graft has a higher risk of revision compared with ACLR performed with a hamstring tendon (HT) graft.

PURPOSE/HYPOTHESIS

To investigate whether ACLR with QT graft had a higher risk of graft failure, revision ACLR, or reoperation compared with HT graft in a high-volume center. We hypothesized that there would be no between-group differences.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This was a registry study with review of medical records. Our study cohort consisted of patients who underwent primary ACLR with either QT or HT graft performed at Copenhagen University Hospital Hvidovre between January 2015 and December 2018. The cohort was identified from the Danish Knee Ligament Reconstruction Registry and linked to the Danish National Patient Registry to identify all hospital contacts after ACLR. The outcome variables were graft failure (rerupture or >3-mm side-to-side difference in anteroposterior [AP] laxity), revision ACLR, reoperation due to cyclops lesion, reoperation due to meniscal injury, and reoperation due to any reason. AP laxity and pivot shift were assessed at 1 year. Kaplan-Meier estimates were used to evaluate the rates of events at 2 years, and comparison was performed with Cox regression analysis.

RESULTS

A total of 475 patients (252 HT, 223 QT) were included. The rate of graft failure at 2 years was 9.4% for the QT group and 11.1% for the HT group (P = .46). For the QT and HT groups, respectively, the rate of revision ACLR was 2.3% and 1.6% (P = .60), the rate of reoperation due to cyclops lesion was 5.0% and 2.4% (P = .13), and the rate of reoperation due to meniscal injury was 4.3% and 7.1% (P = .16). The rate of reoperation due to any reason was 20.5% and 23.6% (P = .37). At 1-year follow-up, AP laxity was 1.4 mm for QT and 1.5 mm for HT (P = .51), and the proportion of patients with a positive pivot shift was 29-30% for both groups.

CONCLUSION

QT and HT grafts yielded similar rates of graft failure, revision ACLR, and reoperation at 2 years of follow-up after ACLR. Graft failure was found in 9% to 11% of patients. Patients with QT ACLR showed a non-statistically significant trend of higher risk for reoperation due to cyclops lesion, and those with HT showed a non-statistically significant trend of higher risk for reoperation due to meniscal injury.

Does practice of meniscus surgery change over time? A report of the 2021 'THE MENISCUS' Webinar

Purpose

The aim of this paper was to report the results presented in the session “Does practice of meniscus surgery change over time?” of the 2021 MENISCUS webinar held online on January 30^th 2021.

Method

During the 2021 MENISCUS webinar, an evaluation of meniscus surgery practices was performed by analyzing: (1) The presentation of the results of a survey conducted among ESSKA members and assessing their current practices in the field of meniscus surgery, (2) Four reports by national experts analyzing the trends in Arthroscopic Partial Meniscectomy (APM) and meniscus repair procedures in their respective countries (France, Belgium, Germany and Japan).

Results

(1) ESSKA Survey: Among the 461 respondents, 75% of surgeons claimed to perform more meniscus repairs and 85% less APM than 5 years ago. In ACL-associated meniscus injuries, a majority of surgeons (60%) indicated to perform a meniscal resection in less than 25% of cases. 25% declared to perform meniscus repair in ACL-associated meniscus injuries in less than 25% of cases and 37% in more than 50% of cases. Half of the respondents repair medial or lateral root tears in less than 25% of cases. Less than 20% of respondents were not familiar with the ESSKA consensus.

(2) National trends: In France, between 2005 and 2017, the APM rate decreased by 21.4%, while the repair rate increased by 320%. In Belgium, between 2007 and 2017, the APM rate decreased by 28.6%. In Germany, between 2010 and 2017 the number of APM decreased by 30%, while the number of repair procedures increased by 55%. Finally, in Japan, between 2011 and 2016, the APM ratio (APM/meniscus procedures) decreased by 16% from 91 to 75% while the repair ratio increased from 9 to 25%.

Conclusion

The 2021 ESSKA members' survey as well as statistics from 4 specifically examined countries (Belgium, France, Germany and Japan) suggest there has been a significant shift over the last years in the surgical management of meniscal lesions towards less APM and more conservative treatments.

The deep lateral femoral notch sign: a reliable diagnostic tool in identifying a concomitant anterior cruciate and anterolateral ligament injury

PURPOSE

The aim of the present study was to investigate the validity and reliability of the deep lateral femoral notch sign (DLFNS) in identifying a concomitant anterior cruciate ligament (ACL)/anterolateral ligament (ALL) rupture and predicting the clinical outcomes following an anatomical single-bundle ACL reconstruction. It was hypothesized that patients with a concomitant ACL/ALL rupture would have an increased DLFNS compared to patients without a concomitant ACL/ALL rupture.

METHODS

The lateral preoperative radiographs and MRI images of 100 patients with an ACL rupture and 100 control subjects were evaluated for the presence of a DLFNS and ACL/ALL rupture, respectively. The patients were evaluated clinically preoperatively and at a minimum 1 year following the ACL reconstruction. A receiver operator curve (ROC) analysis was performed to define the optimal cut-off value of the DLFNS for identifying a concomitant ACL/ALL injury. The relative risk (RR) was also calculated to determine whether the presence of the DLFNS was a risk factor for residual instability or ACL graft rupture following an ACL reconstruction.

RESULTS

The prevalence of DLFNS was 52% in the ACL-ruptured patients and 15% in the control group. At a minimum 1-year follow-up, 35% (6/17) of the patients with DLFNS > 1.8 mm complained of persistent instability, and an MRI evaluation demonstrated a graft re-rupture rate of 12% (2/17). In patients with a DLFNS < 1.8 mm, 8% (7/83) reported a residual instability, and the graft rupture rate was 2.4% (2/83). A DLFNS > 1.8 mm demonstrated a sensitivity of 89%, a specificity of 95%, a negative predictive value of 98%, and a positive predictive value of 89% in identifying a concomitant ACL/ALL rupture. Patients with a DLFNS > 1.8 mm had 4.2 times increased risk for residual instability and graft rupture compared to patients with a DLFNS ≤ 1.8 mm.

CONCLUSIONS

A DLFNS > 1.8 mm could be a clinically relevant diagnostic tool for identifying a concomitant ACL/ALL rupture with high sensitivity and PPV. Patients with a DLFNS > 1.8 mm should be carefully evaluated for clinical and radiological signs of a concomitant ACL/ALL rupture and treated when needed with a combined intra-articular ACL reconstruction and extra-articular tenodesis to avoid a residual rotational instability and ACL graft rupture.

LEVEL OF EVIDENCE

III.

Return to Play After Patellar Tendon Autograft for Primary Anterior Cruciate Ligament Reconstruction in Rugby Players

Background:

There is scant literature on outcomes after anterior cruciate ligament (ACL) reconstruction in rugby players, and no prior study has evaluated the outcomes of bone–patellar tendon–bone (BTB) autograft ACL reconstruction.

Purpose:

To assess the rate of return to play, the timing of that return, and the subsequent graft reinjury rate among rugby players after ACL reconstruction with BTB autograft.

Methods:

The ACL registry at a single hospital was screened for professional and amateur rugby players who had undergone a primary ACL reconstruction with BTB autograft. Professional rugby players were those playing for one of the professional provincial teams in Ireland. Outcomes were analyzed for the rate and timing of return to play, functional outcomes, and subsequent graft ruptures. Additionally, outcomes were compared between professional and amateur athletes.

Study Design:

Case series; Level of evidence, 4.

Results:

A total of 126 patients with 24 months of follow-up were enrolled. The overall rate of return to play was 84.9%, with 75.4% returning to the same level of play; 8.7% of patients did not return to play secondary to non–knee-related issues. The mean time to return was 10.9 ± 4.9 months. Among professional rugby players, 93.3% were able to return at a mean time of 9.7 ± 4.4 months; 80% returned to the same level. The mean Anterior Cruciate Ligament–Return to Sport after Injury score was 78.4 ± 20.2, the Cincinnati knee score was 92.5 ± 8.0, the International Knee Documentation Committee score was 88.2 ± 8.1, and the Marx score was 9.7 ± 5.3. Two patients sustained a subsequent rerupture of the reconstructed ACL, and 4 players sustained a contralateral ACL injury within the follow-up interval of 2 years.

Conclusion:

Rugby players receiving BTB ACL reconstruction demonstrated good clinical outcomes with a high rate of return to sport, with the majority returning before 12 months. The rate of a subsequent ACL injury was low among the authors’ cohort at short-term follow-up.

Hamstrings substitution via anteromedial portal with optional anterolateral ligament reconstruction is the preferred surgical technique for anterior cruciate ligament reconstruction: a survey among ESSKA members

PURPOSE

The objective of this study was to report on a worldwide web-based survey among the ESSKA community developed to investigate current recommendations regarding ACL reconstruction surgical procedures.

METHODS

All contacts in the official mailing list of the ESSKA were contacted to investigate preferences regarding graft type, anterolateral ligament reconstruction, femoral tunnel drilling technique, single-bundle vs double-bundle technique, femoral and tibial fixation methods.

RESULTS

Eight-hundred and twenty responses were analyzed. Hamstrings autograft was the graft of choice in male patients for 634 (79%) and in female patients for 674 (84%) responders, while its preference for ACL reconstruction in professional athletes was for 401 (50%). 480 (63%) surgeons surveyed would include anterolateral ligament reconstruction only if diagnosed and remaining instability after ACL surgery or revision. 598 (75%) respondents were in favor of anteromedial portal for femoral tunnel drilling. The most popular femoral fixation technique was found to be cortical suspension (500-66%), while a compression system was preferred on the tibial side by 537 (71% of the sample).

CONCLUSIONS

This survey study found that HT autograft, single-bundle reconstruction, anteromedial portal for femoral tunnel drilling, cortical suspension systems for femoral fixation and compression systems for tibial fixation represent the current standard of ACLR in a large community of orthopedic surgeons. The present study performed with surgeons who are members of the ESSKA community will help to comprehend the actual ACLR worldwide practice patterns. Due to low response rate, these results should be interpreted with caution and not to be intended to represent the state of the art of ESSKA community.

LEVEL OF EVIDENCE

III.

Effect of Vancomycin Soaking on Anterior Cruciate Ligament Graft Biomechanics

PURPOSE

To evaluate the effect of soaking of anterior cruciate ligament (ACL) grafts in vancomycin solution on graft biomechanical properties at the time of implantation.

METHODS

The central third of patellar tendons was harvested from mature bovine knees and prepared as a tendon-only graft or a bone-tendon-bone (BTB) graft. Tendons were wrapped in gauze soaked in vancomycin solution (VS) (5 mg/mL) or normal saline (NS) and left to stand for 30 minutes at room temperature, simulating graft exposure times in the operating room during ACL reconstruction. Tensile testing was carried out on a materials testing system with (1) low-magnitude loading (60 N at 3 mm/s) with repeated testing of tendon-only grafts; and (2) high-magnitude loading (600 N at 10 mm/min) of BTB grafts. For tendon-only grafts, specimens were first wrapped in NS-soaked gauze and underwent testing, with repeated testing performed after wrapping in gauze soaked in VS or buffered VS (pH 7.0). For BTB grafts, specimens were randomly assigned to treatment with VS or NS.

RESULTS

For tendon-only grafts, there was no difference in Young's modulus (YM) after soaking with VS soaking (baseline, 12.69 MPa; treatment, 16.07 ± 4.44 MPa; P = .99) or buffered VS (baseline, 12.45 ± 4.55 MPa; treatment, 15.56 ± 2.83 MPa; P = .99). For BTB grafts, there were no differences in elongation strain (VS, 46.8% ± 7.0%; NS, 31.5% ± 13.5%, P = .19) or YM (VS, 158.4 ± 15.8 MPa; NS, 158.5 ± 23.3 MPa, P = .99).

CONCLUSIONS

According to controlled biomechanical tests, vancomycin soaking of patellar tendon grafts does not adversely affect time-zero material properties.

CLINICAL RELEVANCE

This study suggests that vancomycin wrapping has no immediate adverse effects on the biomechanical properties of ACL grafts. Randomized controlled trials are warranted to validate the widespread use of vancomycin soaking of tendon grafts for infection prophylaxis during ACL reconstruction.

[Mid-term effectiveness of anterior cruciate ligament revision]

OBJECTIVE

To assess the mid-term effectiveness of anterior cruciate ligament (ACL) revision and to analyze the relevant factors that may affect the surgical outcomes.

METHODS

The clinical data of 24 patients who underwent ACL revision surgery between April 2009 and July 2018 and were followed up for more than 2 years were retrospectively analyzed. There were 20 males and 4 females with a median age of 30 years [interquartile distance (IQR) was (25, 36) years]. The median body mass index was 24.45 kg/m 2 and IQR was (22.93, 25.93) kg/m 2. The median time between ACL revision and reconstruction was 41 months and IQR was (15, 85) months. The direct cause of the failure of reconstruction surgery included 14 cases of trauma, 8 cases of no obvious cause, and 2 cases of infection. During the revision operation, 14 patients had a poor bone tunnel position, all of which were drilled with new tunnels, the remaining 10 patients were freshly modified on the basis of the original bone tunnel. Seventeen patients used autogenous tendon revision, 7 patients used LARS ligament; 16 patients had cartilage injury. The Lysholm score, the International Knee Documentation Committee (IKDC) score, and the Tegner sports rating score were used for functional evaluation before operation, at 1 year after operation, and at last follow-up. The Likert satisfaction score was recorded at last follow-up.

RESULTS

Patients were followed up with a median time of 47 months and IQR was (32, 61) months. The Lysholm score, IKDC score, and Tegner sports rating score were significantly improved at 1 year after operation and at last follow-up when compared with preoperative scores ( P<0.05). There was no significant difference between at last follow-up and at 1 year after operation ( P>0.05). At last follow-up, the median Likert satisfaction score was 4.0 and IQR was (3.0, 4.5). According to the presence or absence of cartilage damage and the type of graft, the above scores at last follow-up were compared between the groups, and the differences were not significant ( P>0.05). At last follow-up, 2 patients had graft fractures due to trauma again, and autogenous iliac bones were taken to fill the bone tunnel, and the second stage was revised; the rest of the patients recovered satisfactorily.

CONCLUSION

With preoperative identification of the cause of ACL reconstruction failure, the stability and function of knee joint can be significantly improved by selecting appropriate bone tunnels and grafts during the revision and by active rehabilitation exercises.

Rate of Force Development Remains Reduced in the Knee Flexors 3 to 9 Months After Anterior Cruciate Ligament Reconstruction Using Medial Hamstring Autografts: A Cross-Sectional Study

BACKGROUND

Anterior cruciate ligament (ACL) rupture is a serious injury with a high prevalence worldwide, and subsequent ACL reconstructions (ACLR) appear to be most commonly performed using hamstring-derived (semitendinosus tendon) autografts. Recovery of maximal muscle strength to ≥90% of the healthy contralateral limb is considered an important criterion for safe return to sports. However, the speed of developing muscular force (ie, the rate of force development [RFD]) is also important for the performance of many types of activities in sports and daily living, yet RFD of the knee extensor and flexor muscles has apparently never been examined in patients who undergo ACLR with hamstring autograft (HA).

PURPOSE

To examine potential deficits in RFD, maximal muscle strength (ie, maximal voluntary isometric contraction [MVIC]), and functional capacity of ACLR-HA limbs in comparison with the healthy contralateral leg and matched healthy controls 3 to 9 months after surgery.

STUDY DESIGN

Cross-sectional study; Level of evidence: 3.

METHODS

A total of 23 young patients who had undergone ACLR-HA 3 to 9 months earlier were matched by age to 14 healthy controls; both groups underwent neuromuscular screening. Knee extensor and flexor MVIC and RFD, as well as functional capacity (single-leg hop for distance [SLHD] test, timed single-leg sit-to-stand [STS] test), were assessed on both limbs. Furthermore, patient-reported knee function (Knee injury and Osteoarthritis Outcome Score) was assessed.

RESULTS

Knee extensor and flexor MVIC and RFD were markedly compromised in ACLR-HA limbs compared with healthy contralateral limbs (MVIC for extensor and flexor, 13% and 26%, respectively; RFD, 14%-17% and 32%-39%) and controls (MVIC, 16% and 31%; RFD, 14%-19% and 30%-41%) (P < .05-.001). Further, ACLR-HA limbs showed reduced functional capacity (reduced SLHD and STS performance) compared with contralateral limbs (SLHD, 11%; STS, 14%) and controls (SLHD, 20%; STS, 31%) (P < .01-.001). Strength (MVIC) and functional (SLHD) parameters were positively related to the duration of time after surgery (P < .05), although this relationship was not observed for RFD and STS.

CONCLUSION

Knee extensor and flexor RFD and maximal strength, as well as functional single-leg performance, remained substantially reduced in ACLR-HA limbs compared with noninjured contralateral limbs and healthy controls 3 to 9 months after reconstructive surgery.

Trauma and femoral tunnel position are the most common failure modes of anterior cruciate ligament reconstruction: a systematic review

PURPOSE

To improve outcomes of anterior cruciate ligament reconstruction (ACLR), it is important to understand the reasons for failure of this procedure. This systematic review was performed to identify current failure modes of ACLR.

METHODS

A systematic search was performed using PubMed, EMBASE, Cochrane, and annual registries for ACLR failures. Studies were included when failure modes were reported (I) of ≥ 10 patients and (II) at a minimum of two-year follow-up. Modes of failure were also compared between different graft types and in femoral tunnel positions.

RESULTS

This review included 24 cohort studies and 4 registry-based studies (1 level I, 1 level II, 10 level III, and 16 level IV studies). Overall, a total of 3657 failures were identified. The most common single failure mode of ACLR was new trauma (38%), followed by technical errors (22%), combined causes (i.e. multiple failure mechanisms; 19%), and biological failures (i.e. failure due to infection or laxity without traumatic or technical considerations; 8%). Technical causes also played a contributing role in 17% of all failures. Femoral tunnel malposition was the most common cause of technical failure (63%). When specifically looking at the bone-patellar tendon-bone (BPTB) or hamstring (HT) autografts, trauma was the most common failure mode in both, whereas biological failure was more pronounced in the HT group (4% vs. 22%, respectively). Technical errors were more common following transtibial as compared to anteromedial portal techniques (49% vs. 26%).

CONCLUSION

Trauma is the single leading cause of ACLR failure, followed by technical errors, and combined causes. Technical errors seemed to play a major or contributing role in large part of reported failures, with femoral tunnel malposition being the leading cause of failure. Trauma was also the most common failure mode in both BPTB and HT grafts. Technical errors were a more common failure mode following transtibial than anteromedial portal technique.

LEVEL OF EVIDENCE

IV.