Factors that affect patient reported outcome after anterior cruciate ligament reconstruction-a systematic review of the Scandinavian knee ligament registers

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.

Analysis of the Swedish Knee Ligament Register: Concomitant injuries, revision surgery and smoking render worse results

PURPOSE

To analyse the 52,199 patients in the Swedish Knee Ligament Register (SKLR) preoperatively, and the patients reaching 5- and 10-year follow-ups who underwent anterior cruciate ligament reconstruction (ACLR), revision ACLR and ACLR on the contralateral side (CACLR). The main hypothesis was that patients undergoing revision ACLR would have worse patient-reported outcome measurements (PROMs) than the primary ACLR group at 10 years and that smoking and concomitant injuries would result in poorer outcomes for all groups.

METHODS

Data from 2005 to 2021 were extracted from the SKLR. Only patients whose ACLR surgery was registered in the SKLR were included for revision ACLR and CACLR. The PROMs consist of the Knee injury and Osteoarthritis Outcome Score (KOOS) and the knee-specific PROM (EQ-5D-3L). PROMs were analysed as a whole and in subgroups based on sex, smoking, graft choice and concomitant injuries.

RESULTS

Poorer KOOS were seen for revisions compared with primary ACLRs at both the 5- and 10-year follow-ups (p = 0.003). Smokers had significantly poorer KOOS than nonsmokers (p < 0.001) preoperatively in all groups, however only in the primary ACLR group at 5 and 10 years. At 10 years, patients who had undergone CACLR had lower KOOS than primary ACLRs (p = 0.03). Concomitant injuries resulted in statistically, significantly poorer KOOS for both primary ACLRs and CACLRs preoperatively and at the follow-ups.

CONCLUSION

The PROMs for revision ACLRs have worse KOOS scores at 10 years compared with the primary ACLRs. The presence of concomitant meniscal or cartilage injuries at the time of ACLR or CACLR were associated with worse PROMs.

LEVEL OF EVIDENCE

Level III.

Anterior cruciate ligament reconstruction: effect of graft type and gender on early to mid-term clinical outcomes

INTRODUCTION

Anterior cruciate ligament (ACL) rupture is a debilitating condition and often requires surgery to restore joint stability. Common autografts used for reconstruction include patella tendon and hamstring tendons. The primary aim of this study was to evaluate the early to mid-term clinical outcomes of ACL reconstruction using validated patient-reported outcome measures (PROMs). The secondary aim was to compare clinical outcomes between patella tendon and hamstring tendon autografts. The tertiary aim was to compare clinical outcomes between males and females.

METHODS

Patients with an ACL rupture were evaluated before and after surgery using PROM scores which included Lysholm, Tegner, International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS), Short Form-12 Item (SF-12) and EQ-5D-5L.

RESULTS

A total of 87 patients were included in the study. All PROM scores significantly improved following surgery (p < 0.001) at a mean follow-up time of 28 months (range 12 to 88 months). The patella tendon subgroup (n = 27) had superior post-operative results as compared to the hamstring tendon subgroup (n = 60) for KOOS sport and recreation (p = 0.005), KOOS quality of life (p = 0.025), KOOS overall (p = 0.026), Tegner (p = 0.046) and IKDC (p = 0.021) scores. There was no significant difference of PROM scores between males (n = 60) and females (n = 27) (p > 0.05).

CONCLUSIONS

ACL reconstruction significantly improves clinical outcomes for patients with symptomatic instability consequent to ACL rupture. Overall, patella tendon autograft resulted in better clinical outcomes as compared to hamstring tendon autograft following surgery. Gender did not influence clinical outcome following ACL reconstruction.

Advances in Polysaccharides for Cartilage Tissue Engineering Repair: A Review

Cartilage repair has been a significant challenge in orthopedics that has not yet been fully resolved. Due to the absence of blood vessels and the almost cell-free nature of mature cartilage tissue, the limited ability to repair cartilage has resulted in significant socioeconomic pressures. Polysaccharide materials have recently been widely used for cartilage tissue repair due to their excellent cell loading, biocompatibility, and chemical modifiability. They also provide a suitable microenvironment for cartilage repair and regeneration. In this Review, we summarize the techniques used clinically for cartilage repair, focusing on polysaccharides, polysaccharides for cartilage repair, and the differences between these and other materials. In addition, we summarize the techniques of tissue engineering strategies for cartilage repair and provide an outlook on developing next-generation cartilage repair and regeneration materials from polysaccharides. This Review will provide theoretical guidance for developing polysaccharide-based cartilage repair and regeneration materials with clinical applications for cartilage tissue repair and regeneration.

Unsupervised Machine Learning of the Combined Danish and Norwegian Knee Ligament Registers: Identification of 5 Distinct Patient Groups With Differing ACL Revision Rates

BACKGROUND

Most clinical machine learning applications use a supervised learning approach using labeled variables. In contrast, unsupervised learning enables pattern detection without a prespecified outcome.

PURPOSE/HYPOTHESIS

The purpose of this study was to apply unsupervised learning to the combined Danish and Norwegian knee ligament register (KLR) with the goal of detecting distinct subgroups. It was hypothesized that resulting groups would have differing rates of subsequent anterior cruciate ligament reconstruction (ACLR) revision.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

K-prototypes clustering was performed on the complete case KLR data. After performing the unsupervised learning analysis, the authors defined clinically relevant characteristics of each cluster using variable summaries, surgeons' domain knowledge, and Shapley Additive exPlanations analysis.

RESULTS

Five clusters were identified. Cluster 1 (revision rate, 9.9%) patients were young (mean age, 22 years; SD, 6 years), received hamstring tendon (HT) autograft (91%), and had lower baseline Knee injury and Osteoarthritis Outcome Score (KOOS) Sport and Recreation (Sports) scores (mean, 25.0; SD, 15.6). Cluster 2 (revision rate, 6.9%) patients received HT autograft (89%) and had higher baseline KOOS Sports scores (mean, 67.2; SD, 16.5). Cluster 3 (revision rate, 4.7%) patients received bone-patellar tendon-bone (BPTB) or quadriceps tendon (QT) autograft (94%) and had higher baseline KOOS Sports scores (mean, 65.8; SD, 16.4). Cluster 4 (revision rate, 4.1%) patients received BPTB or QT autograft (88%) and had low baseline KOOS Sports scores (mean, 20.5; SD, 14.0). Cluster 5 (revision rate, 3.1%) patients were older (mean age, 42 years; SD, 7 years), received HT autograft (89%), and had low baseline KOOS Sports scores (mean, 23.4; SD, 17.6).

CONCLUSION

Unsupervised learning identified 5 distinct KLR patient subgroups and each grouping was associated with a unique ACLR revision rate. Patients can be approximately classified into 1 of the 5 clusters based on only 3 variables: age, graft choice (HT, BPTB, or QT autograft), and preoperative KOOS Sports subscale score. If externally validated, the resulting groupings may enable quick risk stratification for future patients undergoing ACLR in the clinical setting. Patients in cluster 1 are considered high risk (9.9%), cluster 2 patients medium risk (6.9%), and patients in clusters 3 to 5 low risk (3.1%-4.7%) for revision ACLR.

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.

Comparison of Improvement in Patient-Reported Knee Function After Revision and Multiple-Revision ACL Reconstruction Compared With Primary ACL Reconstruction

Background

Graft failure after anterior cruciate ligament reconstruction (ACLR) is a debilitating complication often requiring revision surgery. It is widely agreed upon that functional knee outcomes after revision ACLR (r-ACLR) are inferior compared with those after primary reconstruction. However, data are scarce on outcomes after multiple-revision ACLR (mr-ACLR).

Purpose

To compare patient-reported knee function in terms of Knee injury and Osteoarthritis Outcome Score (KOOS) preoperatively and 1-year postoperatively after primary ACLR, r-ACLR, and mr-ACLR and evaluate the pre- to postoperative improvement in KOOS scores for each procedure.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients from the Swedish National Knee Ligament Registry who underwent their index ACLR between 2005 and 2020 with a minimum age of 15 years at the time of surgery were included in this study. All patients had pre- and postoperative KOOS data. The 1-year postoperative KOOS and the pre- to postoperative changes in KOOS were assessed between patients who underwent primary ACLR and those who underwent subsequent r-ACLR and mr-ACLR.

Results

Of 20,542 included patients, 19,769 (96.2%) underwent primary ACLR, 760 (3.7%) underwent r-ACLR, and 13 (0.06%) underwent mr-ACLR. Patients who underwent r-ACLR had significantly smaller pre- to postoperative changes on all KOOS subscales compared with patients undergoing primary ACLR (P < .0001 for all). Furthermore, patients in the mr-ACLR group had significantly smaller changes in the KOOS-Pain subscale compared with patients in the r-ACLR group (-9 ± 23.3 vs 2.5 ± 18; P = .024).

Conclusion

The study results indicated that while improvement is seen after primary ACLR, r-ACLR, and mr-ACLR, the greatest improvement in functional outcomes is observed after primary ACLR. Patients who underwent at least 1 r-ACLR, specifically mr-ACLR, had lower postoperative outcome scores, indicating that primary ACLR may provide the best chance for recovery after ACL injury.

Comparing Short-Term Knee-Related Quality of Life and Associated Clinical Outcomes Between Youth With and Without a Sport-Related Knee Injury

OBJECTIVE

To compare short-term changes in knee-related quality of life (QOL) and associated clinical outcomes between youth with and without a sport-related knee injury.

DESIGN

Prospective cohort study.

SETTING

Sport medicine and physiotherapy clinics.

PARTICIPANTS

Youth (11-19 years old) who sustained an intra-articular, sport-related knee injury in the past 4 months and uninjured youth of similar age, sex, and sport.

INDEPENDENT VARIABLE

Injury history.

MAIN OUTCOME MEASURES

Knee-related QOL (Knee injury and Osteoarthritis Outcome Score, KOOS), knee extensor and flexor strength (dynamometry), physical activity (accelerometer), fat mass index (FMI; bioelectrical impedance), and kinesiophobia (Tampa Scale for Kinesiophobia, TSK) were measured at baseline (within 4 months of injury) and at 6-month follow-up. Wilcoxon rank sum tests assessed between-group differences for all outcomes. Regression models assessed the association between injury history and outcome change (baseline to 6-month follow-up), considering sex. The influence of injury type, baseline values, and physiotherapy attendance was explored.

RESULTS

Participants' (93 injured youth, 73 uninjured control subjects) median age was 16 (range 11-20) years and 66% were female. Despite greater improvements in KOOS QOL scores (20; 95% confidence interval, 15-25), injured participants demonstrated deficits at 6-month follow-up (z = 9.3, P < 0.01) compared with control subjects, regardless of sex. Similar findings were observed for knee extensor and flexor strength and TSK scores but not for physical activity or FMI. Lower baseline values were associated with greater outcome changes in injured youth.

CONCLUSIONS

Youth have worse knee-related QOL, muscle strength, and kinesiophobia early after a sport-related knee injury than control subjects. Despite improvements, deficits persist 6 months later.

Youth With a Sport-Related Knee Injury Exhibit Significant and Persistent Knee-Related Quality-of-Life Deficits at 12-Month Follow-up Compared to Uninjured Peers

OBJECTIVE: We aimed to compare knee-related quality of life (QOL) between youth with and without an intra-articular, sport-related knee injury at baseline (≤4 months postinjury), 6-month, and 12-month follow-up, and assess the association between clinical outcomes and knee-related QOL. DESIGN: Prospective cohort study. METHODS: We recruited 86 injured and 64 uninjured youth (similar age, sex, sport). Knee-related QOL was assessed with the Knee injury and Osteoarthritis Outcome Score (KOOS) QOL subscale. Linear mixed models (95% confidence interval [CI]; clustered on sex and sport) compared KOOS QOL between study groups over the study period, considering sex-based differences. We also explored the association of injury type (anterior cruciate ligament [ACL]/meniscus injury or other), knee extensor strength (dynamometry), moderate-to-vigorous physical activity (accelerometer), intermittent knee pain (Intermittent and Constant Osteoarthritis Pain [ICOAP] measure), and fear of reinjury (17-item Tampa Scale of Kinesiophobia) with knee-related QOL. RESULTS: Participant median (range) age was 16.4 (10.9-20.1) years, 67% were female, and 56% of injuries were ACL ruptures. Injured participants had lower mean KOOS QOL scores at baseline (-61.05; 95% CI: -67.56, -54.53), 6-month (-41.37; 95% CI: -47.94, -34.80), and 12-month (-33.34; 95% CI: -39.86, -26.82) follow-up, regardless of sex. Knee extensor strength (6- and 12-month follow-up), moderate-to-vigorous physical activity (12-month follow-up), and ICOAP (all time points) were associated with KOOS QOL in injured youth. Additionally, having an ACL/meniscus injury and higher Tampa Scale of Kinesiophobia scores were associated with worse KOOS QOL in injured youth. CONCLUSION: Youth with a sport-related knee injury have significant, persistent knee-related QOL deficits at 12-month follow-up. Knee extensor strength, physical activity, pain, and fear of reinjury may contribute to knee-related QOL. JOSPT 2023;53(8):1-10. Epub: 20 June 2023. doi:10.2519/jospt.2023.11611.

Knee- and Overall Health-Related Quality of Life Following Anterior Cruciate Ligament Injury: A Cross-sectional Analysis of Australian and Canadian Cohorts

OBJECTIVE: To describe the knee- and overall health-related quality of life (QOL) 3 to 12 years after anterior cruciate ligament (ACL) tear, and to assess the association of clinical and structural features with QOL after ACL tear. DESIGN: Cross-sectional analysis of combined data from Australian (n = 76, 5.4 years postinjury) and Canadian (n = 50, 6.6 years postinjury) prospective cohort studies. METHODS: We conducted a secondary analysis of patient-reported outcomes and index knee magnetic resonance imaging (MRI) acquired in 126 patients (median 5.5 [range: 4-12] years postinjury), all treated with ACL reconstruction. Outcomes included knee (ACL Quality of Life questionnaire [ACL-QOL]) and overall health-related QOL (EQ-5D-3L). Explanatory variables were self-reported knee pain (Knee Injury and Osteoarthritis Outcome Score [KOOS-Pain subscale]) and function (KOOS-Sport subscale), and any knee cartilage lesion (MRI Osteoarthritis Knee Score). Generalized linear models were adjusted for clustering between sites. Covariates were age, sex, time since injury, injury type, subsequent knee injuries, and body mass index. RESULTS: The median [range] ACL-QOL score was 82 [24-100] and EQ-5D-3L was 1.0 [-0.2 to 1.0]. For every 10-point higher KOOS-Sport score, the ACL-QOL score increased by 3.7 points (95% confidence interval [CI]: 1.7, 5.7), whereas there was no evidence of an association with the EQ-5D-3L (0.00 points, 95% CI: -0.02, 0.02). There were no significant association between KOOS-Pain and ACL-QOL (4.9 points, 95% CI: -0.1, 9.9) or EQ-5D-3L (0.05 points, 95% CI: -0.01, 0.11), respectively. Cartilage lesions were not associated with ACL-QOL (-1.2, 95% CI: -5.1, 2.7) or EQ-5D-3L (0.01, 95% CI: -0.01, 0.04). CONCLUSION: Self-reported function was more relevant for knee-related QOL than knee pain or cartilage lesions after ACL tear. Self-reported function, pain, and knee structural changes were not associated with overall health-related QOL. J Orthop Sports Phys Ther 2023;53(7):1-12. Epub: 8 June 2023. doi:10.2519/jospt.2023.11838.

Let's talk about sex (and gender) after ACL injury: a systematic review and meta-analysis of self-reported activity and knee-related outcomes

OBJECTIVE

Investigate sex/gender differences in self-reported activity and knee-related outcomes after anterior cruciate ligament (ACL) injury.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

Seven databases were searched in December 2021.

ELIGIBILITY CRITERIA

Observational or interventional studies with self-reported activity (including return to sport) or knee-related outcomes after ACL injury.

RESULTS

We included 242 studies (n=123 687, 43% females/women/girls, mean age 26 years at surgery). One hundred and six studies contributed to 1 of 35 meta-analyses (n=59 552). After ACL injury/reconstruction, very low-certainty evidence suggests females/women/girls had inferior self-reported activity (ie, return to sport, Tegner Activity Score, Marx Activity Scale) compared with males/men/boys on most (88%, 7/8) meta-analyses. Females/women/girls had 23%-25% reduced odds of returning to sport within 1-year post-ACL injury/reconstruction (12 studies, OR 0.76 95% CI 0.63 to 0.92), 1-5 years (45 studies, OR 0.75 95% CI 0.69 to 0.82) and 5-10 years (9 studies, OR 0.77 95% CI 0.57 to 1.04). Age-stratified analysis (<19 years) suggests female athletes/girls had 32% reduced odds of returning to sport compared with male athletes/boys (OR 0.68, 95% CI 0.41 to 1.13, I² 0.0%). Very low-certainty evidence suggests females/women/girls experienced inferior knee-related outcomes (eg, function, quality of life) on many (70%, 19/27) meta-analyses: standardised mean difference ranging from -0.02 (Knee injury and Osteoarthritis Outcome Score, KOOS-activities of daily living, 9 studies, 95% CI -0.05 to 0.02) to -0.31 (KOOS-sport and recreation, 7 studies, 95% CI -0.36 to -0.26).

CONCLUSIONS

Very low-certainty evidence suggests inferior self-reported activity and knee-related outcomes for females/women/girls compared with males/men/boys after an ACL injury. Future studies should explore factors and design targeted interventions to improve outcomes for females/women/girls.

PROSPERO REGISTRATION NUMBER

CRD42021205998.

Self-reported bio-psycho-social factors partially distinguish patellar tendinopathy from other knee problems and explain patellar tendinopathy severity in jumping athletes: A case-control study

OBJECTIVE

To determine what combinations of self-reported factors distinguish patellar tendinopathy (PT) from other knee problems, and explain PT severity variance.

DESIGN

Case-control study.

SETTING

Social media, private practice and National Health Service.

PARTICIPANTS

An international sample of jumping athletes diagnosed with either PT (n = 132; 30.7 ± 8.9 years; 80 males; VISA-P = 61.6 ± 16.0) or another musculoskeletal knee condition (n = 89; 31.8 ± 9.9 years; 47 males; VISA-P = 62.9 ± 21.2) by a clinician in the last 6 months.

MAIN OUTCOME MEASURES

We considered clinical diagnosis (case = having PT vs control = having other knee problems) as the dependent variable. Severity and sporting impact were defined by VISA-P and availability, respectively.

RESULTS

A model comprising seven factors distinguished PT from other knee problems; training duration (OR = 1.10), sport type (OR = 2.31), injured side (OR = 2.28), pain onset (OR = 1.97), morning pain (OR = 1.89), condition acceptability (OR = 0.39) and swelling (OR = 0.37). Sports-specific function (OR = 1.02) and player level (OR = 4.11) explained sporting availability. 44% of PT severity variance was explained by quality of life (β = 0.32), sports-specific function (β = 0.38) and age (β = -0.17).

CONCLUSION

Sports-specific, biomedical and psychological factors partially distinguish PT from other knee problems. Availability is mainly explained by sports-specific factors, while psychosocial factors impact on severity. Adding sports-specific and bio-psycho-social factors into assessments could help better identification and management of jumping athletes with PT.

Explosive hamstrings strength asymmetry persists despite maximal hamstring strength recovery following anterior cruciate ligament reconstruction using hamstring tendon autografts

PURPOSE

To investigate the differences in maximal (isometric and concentric peak torque) and explosive (rate of torque development (RTD)) hamstring and quadriceps strength symmetry between males and females during early- and late-phase rehabilitation after anterior cruciate ligament reconstruction (ACLR) using hamstring tendon (HT) autografts and to determine the interaction of time and sex on maximal and explosive strength symmetry.

METHODS

A total of 38 female and 51 male participants were assessed during early (3-6 months post-operative) and late (7-12 months post-operative) phases of rehabilitation following ACLR. Maximal (concentric and isometric peak torque) and explosive (isometric RTD) hamstring and quadriceps strength were assessed and presented as limb symmetry index (LSI).

RESULTS

Maximal concentric hamstrings asymmetry (Early: 86 ± 14; Late 92 ± 13; p = 0.005) as well as maximal concentric (Early, 73 ± 15; Late 91 ± 12; p < 0.001) and explosive (Early: 82 ± 30; Late: 92 ± 25; p = 0.03) quadriceps asymmetry decreased from early to late rehabilitation. However, there were no significant changes in maximal isometric quadriceps strength and explosive isometric hamstring strength in the same time period. Females had a larger asymmetry in maximal concentric (Females: 75 ± 17; Males: 81 ± 15; p = 0.001) and explosive (Females: 81 ± 32; Males: 89 ± 25; p = 0.01) quadriceps strength than males throughout rehabilitation. There were no sex differences in maximal and explosive hamstring strength. There were no sex by time interactions for any variables.

CONCLUSION

Explosive hamstring strength asymmetry did not improve despite recovery of maximal hamstring strength during rehabilitation following ACLR with HT autografts. While sex did not influence strength recovery, females had larger maximal and explosive quadriceps strength asymmetry compared to males throughout rehabilitation following ACLR.

LEVEL OF EVIDENCE

Level III.

Lower rate of acceptable knee function in adolescents compared with young adults five years after acl reconstruction: results from the swedish national knee ligament register

Background

The number of studies with a large cohort of patients that primarily focus on patient-reported outcomes after ACL reconstruction in children and adolescents is limited. The purpose of the present study was to determine whether patient age affects the proportion of patients that achieve a patient-acceptable symptom state (PASS) on the Knee injury and Osteoarthritis Outcome Score (KOOS) subscales one, two, five and 10 years after an ACL reconstruction.

Methods

The patient data in the present study were extracted from the Swedish National Knee Ligament Register (SNKLR). Patients aged between five and 35 years that underwent a primary ACL reconstruction between 1 January 2005 and 31 December 2017 and had completed the KOOS questionnaire at the one-, two-, five- or 10-year follow-up were included. A total of 2,848 patients met the inclusion criteria and were included in the study; 47 paediatric patients (females 5–13, males 5–15 years), 522 adolescents (females 14–19, males 16–19 years) and 2,279 young adults (females 20–35, males 20–35 years). The results from the KOOS were presented as the mean and 95% confidence interval (CI) for the mean. For comparisons between groups, the chi-square test was used for non-ordered categorical variables. For pairwise comparisons between groups, Fisher’s exact test (2-sided) was used for dichotomous variables. All the statistical analyses was set at 5%.

Results

Adolescents reported a significantly lower score than young adults on the KOOS4 at the two- (68.4 vs. 72.1; P < 0.05), five- (69.8 vs. 76.0; P < 0.05) and 10-year follow-ups (69.8 vs. 78.2; P < 0.05). Moreover, a significantly smaller proportion of adolescents achieved a PASS on each of the KOOS subscales when compared with young adults at the five-year follow-up (Symptoms: 83.3% vs. 91.6%; Pain: 42.9% vs. 55.3%; Function in daily living: 31.4% vs. 41.1%; Function in sports and recreational activities: 42.3% vs. 55.7%; Knee-related quality of life: 50.0% vs. 65.0%; P < 0.05).

Conclusions

A significantly smaller proportion of adolescents achieved a PASS on each of the KOOS subscales when compared with young adults five years after ACL reconstruction. The results of the present study provide important information for physicians and physiotherapists treating young patients after an ACL injury and they can aid in providing realistic expectations in terms of the mid- and long-term outcomes.

Level of evidence

Prospective Observational Register/Cohort Study, Level II.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05727-6.

Cutoff Value for the Patient Acceptable Symptom State of the Thai IKDC Subjective Knee Form in Patients After Primary ACL Reconstruction

Background

The Patient Acceptable Symptom State (PASS) cutoff is the value on a patient-reported outcome measure beyond which patients consider themselves to be "feeling well." There are limited data regarding the PASS threshold for non-English versions of the International Knee Documentation Committee-Subjective Knee Form (IKDC-SKF).

Purpose

To establish the PASS cutoff for the Thai version of the IKDC-SKF for patients undergoing primary anterior cruciate ligament reconstruction (ACLR) and to identify factors to achieve PASS after surgery.

Study Design

Cohort study (diagnosis); Level of evidence, 3.

Methods

Included in this study were patients aged 18 to 50 years who had undergone primary unilateral ACLR between January 2016 and February 2020. After enrollment, patients completed the Thai IKDC-SKF and answered the anchor question for determining the PASS.

Results

Questionnaires were sent to 321 patients, of whom 173 (53.9%) responded. The vast majority (156 patients; 90.2%) considered themselves to have achieved the PASS. This group of patients had significantly higher IKDC scores than did those who did not have an acceptable symptom state (79.6 ± 14.2 vs 60.7 ± 16.5; P < .001). The receiver operating characteristic curve of the IKDC score for predicting the PASS had an area under the curve of 0.82 (95% CI, 0.72-0.91). The optimum PASS cutoff of the Thai IKDC-SKF was a score of 74.2 (sensitivity, 0.72; specificity, 0.82). Factors that provided favorable odds for achieving the PASS were the use of a hamstring tendon autograft (odds ratio, 4.1; 95% CI, 1.5-20.6) and the absence of a patellofemoral chondral lesion (odds ratio, 3.8; 95% CI, 1.03-14.1).

Conclusion

For patients undergoing ACLR, the cutoff for the PASS of the Thai version of the IKDC-SKF was a score of 74.2. Two surgery-related factors provided favorable odds for achieving the PASS: the use of a hamstring tendon autograft and the absence of a patellofemoral chondral lesion.

Tibial slope correction combined with second revision ACLR grants good clinical outcomes and prevents graft rupture at 7-15-year follow-up

PURPOSE

To update previously published outcomes (at 2-8 years) of second revision anterior cruciate ligament reconstruction (ACLR) combined with tibial deflexion osteotomy (TDO), after an interval of 5 more years (at 7-15 years), and monitor evolution of clinical scores and progression of osteoarthritis.

METHODS

The initial retrospective consecutive series included nine patients that underwent one-stage second revision ACLR with TDO, all of whom were contacted for second follow-up at minimum 7 years. An independent observer collected IKDC-SKF, the Lysholm score, and assessed radiographs for signs of osteoarthritis.

RESULTS

Of the nine original patients, seven were assessed at the clinic, one could only be assessed by telephone, and one was lost to follow-up. At final follow-up of 9.9 ± 3.0 years, the eight patients assessed maintained or improved clinical scores, compared to the previous follow-up at 4.0 ± 2.9 years. The mean Lysholm score improved from 73.8 ± 5.8 (65-82) to 84.5 ± 11.9 (59-95), and IKDC improved from 71.6 ± 6.2 (62-79) to 82.9 ± 12.1 (61-98). Of the three patients that had signs of arthritis at the previous follow-up, the stage of osteoarthritis increased in one (from grade 2 to grade 3), remained unchanged in one, and could not be assessed in one.

CONCLUSION

At 7-15 years following second revision ACLR with TDO, patients maintained or improved clinical scores compared to the previous follow-up at 2-8 years, without retears or reoperations. Although eight of the nine knees had meniscectomies or meniscal sutures, osteoarthritis progressed in only one of the six knees that had signs of arthritis at the previous follow-up. These results confirm that TDO can protect the ACL graft from retear, with minimal progression of osteoarthritis and/or risks of meniscal tears, suggesting that correction of excessive tibial slope should be considered when performing ACLR, whether a revision or primary procedure.

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.

A larger side-to-side difference in anterior knee laxity increases the prevalence of medial and lateral meniscal injuries in patients with ACL injuries

PURPOSE

The objective of this study was to investigate factors that influence the prevalence of medial and lateral meniscal injuries at the time of anterior cruciate ligament (ACL) reconstruction in patients with ACL injuries.

METHODS

Patients with ACL injuries at 9 institutions were enrolled in this multicentre study. Age, sex, duration between injury and surgery, pivot shift test grade, anterior knee laxity determined using the Kneelax 3 arthrometer, and other variables were assessed by logistic regression analysis. Meniscal conditions were evaluated via arthroscopy.

RESULTS

In all, 830 patients were enrolled. The prevalence of medial and lateral meniscal tears was 32.0% (266 knees) and 26.5% (220 knees), respectively. Significant factors that influenced the prevalence of medial meniscal injuries were age [odds ratio (OR) 1.03; P = 0.000], side-to-side differences in instrumented anterior knee laxity before surgery (OR 1.12; P = 0.002), duration between injury and surgery (≥ 12 months) (OR 1.86; P = 0.023), and pivot shift test grade (OR 1.36; P = 0.014). Significant factors of lateral meniscal injury were side-to-side differences in anterior knee laxity before surgery (OR 1.12; P = 0.003) and the male sex (OR 1.50; P = 0.027).

CONCLUSION

Greater anterior knee laxity, age, a longer duration between injury and surgery, and a higher pivot shift test grade predicted medial meniscal injury. Greater anterior knee laxity and the male sex predicted lateral meniscal injury. In patients with ACL injuries, the importance of side-to-side differences in anterior knee laxity should be rediscovered from the viewpoint of meniscal conditions.

LEVEL OF EVIDENCE

Level III.

Revision anterior cruciate ligament reconstruction and outcomes with different autografts in a population with kneeling customs

OBJECTIVES

This study was designed to evaluate, compare the mid-term functional outcome of revision anterior cruciate ligament reconstruction (ACLR) using different autografts and assess the cause of failure of primary ACLR in an Omani population with kneeling customs.

MATERIALS AND METHODS

Patients with failed primary ACLR who underwent revision ACLR using autografts were included in this retrospective study. The cause of primary ACLR failure and the functional outcome was assessed using the Tegner-Lyholm knee score and compared among bone patella tendon-bone (BPTB), quadriceps tendon (QT), semitendinosus gracilis (STG) autografts used.

RESULTS

One hundred two patients (102 male) were included in the study with a minimum follow-up of 2 years. Thirty-one patients underwent revision with BPTB, 34 with STG and 19 with QT autografts. Majority of the patients (70.23%) achieved good-to-excellent functional outcome based on their Tegner-Lysholm scores. The functional outcome of different autografts was comparable to each other based on Kruskal-Wallis test. The causes of primary ACLR failure were failure due to trauma in 58.33% of patients, technical failure in 22.61% of patients, and nontraumatic failure in 19.04% of patients.

CONCLUSIONS

The functional outcome of revision ACLR in this Middle Eastern Asian Omani population was good-to-excellent, with the patients experiencing no difficulty in performing activities of daily living, including kneeling activities. The outcome of different autografts, BTPB, QT, STSG is similar in high knee flexion patients with no autograft found to be superior. The findings of this study add to the literature on functional outcomes after primary and revision ACLR in a customary kneeling population.

LEVEL OF EVIDENCE III

Patient-Reported Outcome, Return to Sport, and Revision Rates 7-9 Years After Anterior Cruciate Ligament Reconstruction: Results From a Cohort of 2042 Patients

BACKGROUND

Long-term patient-reported outcome measures (PROMs), rates of return to sport, and revision risk after anterior cruciate ligament (ACL) reconstruction (ACLR) are not well understood.

PURPOSE

To provide long-term follow-up of PROMs, return-to-sport rates, and revision rates after ACLR and to identify predictors for poor outcome.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A total of 2042 patients were included in an institutional ACL registry (2009-2013) and longitudinally followed. PROMs were completed preoperatively and at all follow-up time points. Questions regarding return to sport and knee stability were completed at final follow-up. Predictors for poor outcome on the International Knee Documentation Committee (IKDC) score were estimated in a regression model incorporating risk factors such as patient characteristics, graft choice, and concomitant injuries. Revision rates and risk of subsequent non-ACL surgeries were calculated.

RESULTS

Autografts were used in 76% of the patients (patellar tendon, 62%; hamstring grafts, 38%). Allografts were used in 24% of patients. The questionnaires were returned by 1045 (51.2%) patients at a mean of 7.2 years (range, 5.0-9.8 years) after surgery. Improvements in IKDC score of >30 points were sustained for all patient categories. The strongest predictor for lesser improvement in IKDC score was a cartilage lesion >2 cm2 identified during surgery. Male sex and college education completion were associated with improved IKDC scores. Meniscal lesions did not predict change) in the IKDC score. A total of 69% of patients had returned to sport after 8.1 years (range, 6.7-9.8 years). The main reason for not returning to sport was fear of reinjury. The revision rate was 7.2% after 9 years (range, 8-11 years), 13% of patients needed subsequent ipsilateral non-ACL surgery, and 6% underwent contralateral ACLR. The absence of a meniscal tear, younger age, and male sex were predictors for revision. Graft choice did not predict PROM results or revision risk.

CONCLUSION

Improvements in IKDC scores were sustained 7 years after ACLR. The strongest predictor for poor outcome was a cartilage lesion >2 cm2. Patients can expect a 70% return-to-sport rate and an 87% chance of their knee feeling stable during daily and athletic activities after 8 years. Young male patients have better PROM scores but a higher risk of revision. There is a 26% chance of subsequent knee surgery within 9 years, including a revision rate of 7%, subsequent non-ACL surgery to the operated knee in 13%, and a 6% chance of contralateral ACLR.

Self-Reported Symptoms of Depression and Anxiety After ACL Injury: A Systematic Review

Background:

Depression and anxiety symptoms can occur in patients following an anterior cruciate ligament (ACL) injury, and the presence of these symptoms has been associated with poorer self-reported knee function in this type of injury.

Purpose:

To investigate the prevalence and severity of self-reported symptoms of depression and anxiety following an ACL injury.

Study Design

Systematic review; Level of evidence, 4.

Methods:

PubMed, Cochrane Library, Embase, PsycINFO, AMED, and PEDro databases were searched using a combination of keywords relating to ACL, depression, anxiety, and their synonyms. Inclusion criteria were clinical studies written in English that reported on patients with an injured and/or reconstructed ACL and assessed symptoms of depression and/or anxiety. Data extraction was performed independently by 2 authors. Data synthesis was performed using an emergent synthesis approach. The quality of the included studies was assessed using the methodological index for non-randomized studies or the Mixed-Methods Appraisal Tool. Certainty of evidence was determined using the Grading of Recommendations Assessment, Development and Evaluation.

Results:

After abstract screening, 37 studies were assessed in full text, of which 16 were included. The studies comprised 682 patients (417 male [61%]). The depression symptoms appeared to be more severe in elite athletes compared with recreational athletes. Symptoms decreased over time from moment of ACL reconstruction to up to 2 years postoperatively. The prevalence of self-reported symptoms of anxiety after an ACL injury was reported in 1 study (2%). There were no differences in anxiety symptoms between professional and amateur athletes or between adolescents and adults. The overall quality of the studies was low or very low.

Conclusion:

Patients who sustain an ACL injury can suffer from symptoms of depression, especially during the first 6 weeks after ACL reconstruction. Depressive symptoms are more common among professional versus nonprofessional athletes. Levels of anxiety symptoms were not above the cutoffs for a diagnosis of anxiety after an ACL injury.

Concomitant full-thickness cartilage lesions do not affect patient-reported outcomes at minimum 10-year follow-up after ACL reconstruction

PURPOSE

To compare patients with a concomitant full-thickness cartilage lesion and anterior cruciate ligament (ACL) injury to patients with an isolated ACL injury at 10-15 years post ACL reconstruction.

METHODS

This is a longitudinal follow-up of a cohort of 89 patients that were identified in the Norwegian National Knee Ligament Registry and included in the index study in 2007. The study group consisted of 30 patients that underwent ACL reconstruction and had a concomitant, isolated full-thickness cartilage lesion (International Cartilage Repair Society [ICRS] grade 3-4). Each study patient was matched with two control patients who underwent ACL reconstruction but had no cartilage lesions (ICRS grade 1-4) (n = 59). At a median follow-up of 10.2 years (range 9.9-15.6), 65 patients (74%) completed the Knee Injury and Osteoarthritis Outcome Score (KOOS), which was the main outcome measure, resulting in 23 pairs after matching.

RESULTS

At a follow-up of 10-15 years after ACL reconstruction, no significant differences in KOOS were found between patients with a concomitant full-thickness cartilage lesion and patients without cartilage lesions. There was also no significant difference between the two groups when comparing the change over time in KOOS scores from preoperative to follow-up. Both groups showed significant improvement in all KOOS subscales from preoperative to follow-up, except for in the Symptoms subscale for the control group. The greatest improvement was in the QoL subscale for the study group.

CONCLUSION

ACL-reconstructed patients with a full-thickness cartilage lesion did not report worse outcomes at 10-15 years after surgery compared with patients with an isolated ACL injury. Our findings support that there is no long-term negative effect of a concomitant cartilage lesion in an ACL-reconstructed knee. These findings should be considered when discussing treatment and informing about the expected long-term outcome after ACL reconstruction to patients with such combined injuries.

LEVEL OF EVIDENCE

II.

Quadriceps tendon autograft is becoming increasingly popular in revision ACL reconstruction

PURPOSE

To evaluate trends in revision anterior cruciate ligament reconstruction (ACL-R), with emphasis on intra-articular findings, grafts, and concurrent procedures. It was hypothesized that revision ACL-Rs over time show a trend toward increased complexity with increased use of autografts over allografts.

METHODS

This was a two-center retrospective study including patients undergoing revision ACL-R between 2010 and 2020. Demographic and surgical data including intra-articular findings and concurrent procedures were collected and compared for the time periods 2010-2014 and 2015-2020. All collected variables were compared between three pre-defined age groups (< 20 years, 20-30 years, > 30 years), right and left knees, and males and females. A time series analysis was performed to assess trends in revision ACL-R.

RESULTS

This study included 260 patients with a mean age of 26.2 ± 9.4 years at the time of the most recent revision ACL-R, representing the first, second, third, and fourth revision ACL-R for 214 (82%), 35 (14%), 10 (4%), and 1 (< 1%) patients, respectively. Patients age > 30 years showed a significantly longer mean time from primary ACL-R to most recent revision ACL-R (11.1 years), compared to patients age < 20 years (2.2 years, p < 0.001) and age 20-30 years (5.5 years, p < 0.05). Quadriceps tendon autograft was used significantly more often in 2015-2020 compared to 2010-2014 (49% vs. 18%, p < 0.001). A high rate of concurrently performed procedures including meniscal repairs (45%), lateral extra-articular tenodesis (LET; 31%), osteotomies (13%), and meniscal allograft transplantations (11%) was shown. Concurrent LET was associated with intact cartilage and severely abnormal preoperative knee laxity and showed a statistically significant and linear increase over time (p < 0.05). Intact cartilage (41%, p < 0.05), concurrent medial meniscal repairs (39%, p < 0.05), and LET (35%, non-significant) were most frequently observed in patients aged < 20 years.

CONCLUSION

Quadriceps tendon autograft and concurrent LET are becoming increasingly popular in revision ACL-R. Intact cartilage and severely abnormal preoperative knee laxity represent indications for LET in revision ACL-R. The high rate of concurrent procedures observed demonstrates the high surgical demands of revision ACL-R.

LEVEL OF EVIDENCE

Level III.

Physical prognostic factors predicting outcome following anterior cruciate ligament reconstruction: A systematic review and narrative synthesis

BACKGROUND

Anterior cruciate ligament (ACL) injuries are common. Many patients undergo ACL reconstruction (ACLR), with rehabilitation key to successful outcome. Understanding physical prognostic factors is integral to clinical decision-making, but factors predicting outcome are inadequately defined. The objective was to establish physical prognostic factors predicting outcome following ACLR.

METHODS

A systematic review following a published protocol (CRD42019127732) searched MEDLINE, CINAHL, EMBASE, key journals and grey literature to November 28, 2020. Prospective cohort studies, participants ≥16 years of age who had undergone ACLR were included, with multi-ligament and/or ACL repair surgery, and studies not published in English excluded. Two independent reviewers conducted searches, extracted data, assessed risk of bias (QUIPS) and overall quality of evidence (GRADE). Meta-analysis was not possible, therefore narrative synthesis was performed.

RESULTS

13 studies (16 articles) were included (1 low, 12 high risk of bias). Low-level evidence supports postoperative degenerative changes and poor lower-limb strength predicting poorer outcome long term (KOOS). Very low-level evidence supports greater postoperative quadriceps strength predicting improved functional performance medium term; with lower body mass index predicting improvement of multiple outcome measures.

CONCLUSION

Limited evidence of low or very low-level indicates multiple prognostic factors predicting outcome following ACLR. A high-quality prognostic study is required.

[Quality in sports orthopedics and traumatology: more than just return to play]

Quality assessment is gaining in importance in sports orthopedics and traumatology. Structural, process and results quality are differentiated as central quality dimensions in healthcare. Structural quality is understood to mean the capabilities of the institution involved in patient care with its human and material resources. Structural quality can be documented using institutional certificates (e.g. knee center of the German Knee Society, DKG) or personal certificates (e.g. DKG knee surgeon). Process quality evaluates all medical, nursing and administrative activities that are involved in the care process. The outcome quality describes changes in the patient's state of health that can be attributed to medical, nursing and physiotherapeutic measures. The measurement of the outcome quality can be broken down into objective and subjective parameters. In terms of subjective parameters patient reported outcome measures (PROM) play a major role. Another quality initiative in recent years can be seen in healthcare research. In this context medical registers play a role in which long-term healthcare data are prospectively collated and involves data on the quality of the process and outcome. The outcome quality is also the focus of value-based reimbursement systems.

Prediction of improvement after anterior cruciate ligament reconstruction

Objective

The retrospective investigation was carried out to assess whether subjects who fulfilled our proposed recruitment criteria responded more favorably to anterior cruciate ligament reconstruction (ACLR) than those who did not.

Methods

We retrospectively analyzed 109 skeletally mature subjects (78 men and 31 women) according to the following proposed criteria of recruitment: (1) pre-injury Tegner activity score ≥7 and a wish to return to a professional sports activity, (2) residual knee instability following injury and/or (3) age <20 years at the operation. The primary outcome was an improvement between assessment A (before operation) and B (mean follow-up of 1.6 years) in the average score for four of the five Knee injury and Osteoarthritis Outcome Score (KOOS) subscales, covering pain, symptoms, difficulty in sports and recreational activities, and quality of life (KOOS₄).

Results

The proposed recruitment criteria for ACLR were met by 58 subjects (53%). There were 49 subjects (45%) who improved between assessment A and B. Subjects who met proposed recruitment criteria were more likely to improve clinically after ACLR (OR 5.7, 95% CI 2.5–13.3).

Conclusions

Fulfillment of proposed recruitment criteria was a strong predictive factor for outcome improvement in short- to medium-term follow-up after ACLR.

Level of evidence

Case-control study. Level of evidence 3.

Functional outcome of osteochondral autograft is equivalent in stable knee and in anterior cruciate ligament reconstruction

INTRODUCTION

Anterior cruciate ligament (ACL) tears are associated in 10% to 20% of cases with extensive traumatic focal osteochondral damage. Ligament reconstruction may require osteochondral autograft for symptomatic osteochondral lesions. Combined ACL and chondral or osteochondral reconstruction is poorly evaluated in the literature; osteochondral reconstruction in stable knee better documented. The objective of this study was to compare functional results after osteochondral autograft transfer (OAT) for significant symptomatic femoral condyle defect, in stable or stabilised knees (concomitant ACL reconstruction). The hypothesis was that functional results are equivalent in both groups.

MATERIAL & METHOD

This was a single-centre retrospective comparative observational study of patients consecutively operated on between 2000 and 2018. Fifty patients met the inclusion criteria and were divided into two groups: Group 1 (OAT+ACL, n=13) and group 2 (OAT on stable knee, n=37). The following criteria were recorded at follow-up: pain (VAS), KOOS, IKDC and Lysholm scores and Hughston radiologic score, and time to return to sport. Mean follow-up was 79.7±60 months in group 1 and 86.4±62 months in group 2.

RESULTS

Ten patients were included for analysis in group 1 and 30 in group 2. Cartilage lesion size was comparable between groups: 1.6±1.20 cm² for group 1 and 2.3±1.3 cm² for group 2 (ns). One complication (infection with favourable course) was observed in group 2. Sport was resumed at 8.7±2.7 vs. 8.4±3.3 months, respectively. Mean subjective scores were respectively 83.3±7.4 and 75.4±14 for Lysholm, 89.7±7.8 and 89.7±19.6 for KOOS, 78±13.7 and 72.2±12.9 for subjective IKDC, 0.5±0.5 and 0.8±0.9 for pain on VAS and 3 and 3 for radiological Hughston radiologic score, with no significant differences between groups.

CONCLUSION

Symptomatic focal osteochondral lesions treated by osteochondral autograft transfer gives the same outcome on stable or stabilised knee.

LEVEL OF EVIDENCE

IV; retrospective study.

Knee performance and self-efficacy trajectory curves after ACL reconstruction: A longitudinal study

OBJECTIVES

To examine knee flexion range-of-motion, quadriceps strength, and knee self-efficacy trajectory curves over 6 months after anterior cruciate ligament reconstruction (ACLR), stratified by patients' Month-6 sports activity level.

DESIGN

Prospective longitudinal study.

SETTING

Hospital outpatient physiotherapy department.

PARTICIPANTS

595 individuals after unilateral ACLR (mean age, 27 years).

MAIN OUTCOME MEASURES

At 2-, 3-, and 6-months post-surgery, knee flexion range-of-motion, quadriceps strength, and self-efficacy were quantified. Flexion range-of-motion was additionally measured at 2- and 4-weeks post-surgery. Sports activity levels were assessed using the Tegner Activity Score at 6-months post ACLR.

RESULTS

The various measures improved nonlinearly over time, with substantial improvements observed in the first 2-4 months post-surgery. In multivariable generalized least squares models, greater knee flexion range-of-motion, quadriceps strength, and self-efficacy over time were significantly associated with higher Month-6 Tegner levels (all P values < 0.01). Additionally, receiving a bone-patellar-tendon-bone graft or meniscal repair was associated with lower quadriceps strength trajectories (P-values<0.001) while female sex was associated with lower knee self-efficacy trajectories (P = 0.02).

CONCLUSIONS

Greater knee flexion range-of-motion, quadriceps strength, and self-efficacy were associated with higher Month-6 Tegner levels. The derived trajectory curves may be useful for effective management decision making and adequate results interpretation during the rehabilitation process.

Clinical Outcomes After Anterior Cruciate Ligament Injury: Panther Symposium ACL Injury Clinical Outcomes Consensus Group

A stringent outcome assessment is a key aspect of establishing evidence-based clinical guidelines for anterior cruciate ligament (ACL) injury treatment. To establish a standardized assessment of clinical outcome after ACL treatment, a consensus meeting including a multidisciplinary group of ACL experts was held at the ACL Consensus Meeting Panther Symposium, Pittsburgh, Pennsylvania, USA, in June 2019. The aim was to establish a consensus on what data should be reported when conducting an ACL outcome study, what specific outcome measurements should be used, and at what follow-up time those outcomes should be assessed. The group reached consensus on 9 statements by using a modified Delphi method. In general, outcomes after ACL treatment can be divided into 4 robust categories: early adverse events, patient-reported outcomes (PROs), ACL graft failure/recurrent ligament disruption, and clinical measures of knee function and structure. A comprehensive assessment after ACL treatment should aim to provide a complete overview of the treatment result, optimally including the various aspects of outcome categories. For most research questions, a minimum follow-up of 2 years with an optimal follow-up rate of 80% is necessary to achieve a comprehensive assessment. This should include clinical examination, any sustained reinjuries, validated knee-specific PROs, and health-related quality of life questionnaires. In the midterm to long-term follow-up, the presence of osteoarthritis should be evaluated. This consensus paper provides practical guidelines for how the aforementioned entities of outcomes should be reported and suggests the preferred tools for a reliable and valid assessment of outcome after ACL treatment.

Editorial Commentary: The Hospital for Special Surgery Anterior Cruciate Ligament Postoperative Satisfaction Survey-Just Another Scoring System or a Step Forward? "You Can't Always Get What You Want"

An interesting, easy-to-use scoring system to evaluate the results after anterior cruciate ligament reconstruction developed at the Hospital for Special Surgery-the Hospital for Special Surgery Anterior Cruciate Ligament Post-operative Satisfaction Survey (HSS ACL-SS) score-is presented in this issue. The score can be used both for a physical follow-up and for a web-based questionnaire. It appears to have the opportunity to replace older scores that are more complicated to complete.

Physical prognostic factors predicting outcome following anterior cruciate ligament reconstruction: protocol for a systematic review

INTRODUCTION

Injuries of the anterior cruciate ligament (ACL) are a common musculoskeletal complication and can cause significant reduction in patient function and quality of life. Many undergo ACL reconstruction, with high-quality rehabilitation key to successful outcome. Knowledge of physical prognostic factors, such as quadriceps strength, is crucial to inform rehabilitation and has important implications for outcome following ACL reconstruction. However, these factors predicting outcome are poorly defined. Therefore, the aim of this systematic review is to establish physical prognostic factors predictive of outcome in adults following ACL reconstruction. Outcome will be subdivided into two groups of outcome measures, patient-reported and performance-based. Physical prognostic factors of interest will reflect a range of domains and may be modifiable/non-modifiable. Results will help decide most appropriate management and assist in planning and tailoring preoperative and postoperative rehabilitation.

METHODS AND ANALYSIS

This systematic review protocol is reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols. MEDLINE, CINAHL and EMBASE databases, key journals and grey literature will be searched from inception to July 2019. Prospective cohort studies including participants aged ≥16 years who have undergone ACL reconstruction will be included, with articles focusing on multi-ligament reconstructions and ACL repair surgery, or not published in English excluded. Two independent reviewers will conduct searches, assess study eligibility, extract data, assess risk of bias (Quality in Prognostic Studies tool) and quantify overall quality of evidence (modified Grading of Recommendations, Assessment, Development and Evaluation guidelines). If possible, a meta-analysis will be conducted, otherwise a narrative synthesis will ensue focusing on prognostic factors, risk of bias of included studies and strength of association with outcomes.

ETHICS AND DISSEMINATION

Findings will be published in a peer-reviewed journal, presented at conferences and locally to physiotherapy departments. Ethical approval is not required for this systematic review.

PROSPERO REGISTRATION NUMBER

CRD42019127732.

Cartilage damage at the time of anterior cruciate ligament reconstruction is associated with weaker quadriceps function and lower risk of future ACL injury

PURPOSE

To determine whether articular cartilage damage noted at the time of primary anterior cruciate ligament reconstruction (ACLR) affects the likelihood of achieving ≥ 90% symmetry for isokinetic extension strength at 6 months after surgery or risk of recurrent ACL injury.

METHODS

Five hundred and eight patients underwent primary ACLR and diagnostic arthroscopy. All identified cartilage lesions were graded using the Outerbridge system. All patients underwent isokinetic strength testing. The association between cartilage Outerbridge grade and a ≥ 90% Limb Symmetry Index (LSI) and recurrent ACL injury risk at mean 38.7 month follow-up (SD 31.8) was evaluated via multivariate regression analysis.

RESULTS

Grade 2 or higher damage was present in 394 (77.5%) of patients, grade 3 or higher in 143 (28.1%) and grade 4 in 83 (16.4%) at time of ACLR. Ipsilateral ACLR graft rupture occurred in 31 (6.1%) of patients. Contralateral ACL injury occurred in 19 (3.7%). Patients with grade 2 or higher damage were significantly less likely to meet an LSI goal of ≥ 90% for fast (300°/s) isokinetic extension. There was no association with slow isokinetic extension. Cartilage lesion severity at or beyond grade 2 had a similar effect on isokinetic testing results regardless of compartment involvement or performance of microfracture. Patients with grade 2-4 cartilage damage were less likely to sustain a second ipsilateral ACL injury or a contralateral native ACL injury.

CONCLUSIONS

Cartilage damage seen at time of ACL reconstruction is common and associated with lower likelihood of achieving ≥ 90% symmetry for isokinetic extension strength at 6 months after surgery. However, lower recurrent ACL injury rates are seen in patients with concurrent cartilage damage. These data may inform future clinical decisions regarding operative managment of recurrent ACL injuries.

LEVEL OF EVIDENCE

III.

Strength in numbers? The fragility index of studies from the Scandinavian knee ligament registries

PURPOSE

The fragility index (FI) is a metric to evaluate the robustness of statistically significant results. It describes the number of patients who would need to change from a non-event to an event to change a result from significant to non-significant. This systematic survey aimed to evaluate the feasibility of applying the FI to findings related to anterior cruciate ligament (ACL) reconstruction in the Scandinavian knee ligament registries.

METHODS

The PubMed, EMBASE, Cochrane Library and AMED databases were searched. Studies from the Scandinavian knee ligament registers were eligible if they reported a statistically significant result (p < 0.05) for any of the following dichotomous outcomes; ACL revision, contralateral ACL reconstruction or the presence of postoperative knee laxity. Only studies with a two-arm comparative analysis were included. Eligibility assessment, data extraction and quality assessment were performed by two independent reviewers. The dichotomous analyses were stratified according to the grouping variable for the two comparative arms as follows; age, patient sex, activity at injury, graft choice, drilling technique, graft fixation, single- versus double-bundle, concomitant cartilage injury and country. The two-sided Fisher's exact test was used to calculate the FI of all statistically significant analyses.

RESULTS

From 158 identified studies, 13 studies were included. They reported statistical significance for a total of 56 dichotomous analyses, of which all but two had been determined by a time-to-event analysis. The median sample size for the arms was 5540 (range 92-38,666). The mean FI for all 56 dichotomous analyses was 80.6 (median 34.5), which means that a mean of 80.6 patients were needed to change outcome status to generate a non-significant result instead of a significant one. Seventeen analyses (30.4%) immediately became non-significant when performing the two-sided Fisher's exact test and, therefore, had an FI of 0. The analyses related to age were the most robust, with a mean FI of 178.5 (median 116, range 1-1089). The mean FI of the other grouping variables ranged from 0.5 to 48.0.

CONCLUSION

There was large variability in the FI in analyses from the Scandinavian knee ligament registries and almost one third of the analyses had an FI of zero. The FI is a rough measurement of robustness when applied to registry studies, however, future studies are needed to determine the most appropriate metric for robustness in registry studies. The use of the FI can provide clinicians with a deeper understanding of significant study results and promotes an evidence-based approach in the clinical care of patients.

LEVEL OF EVIDENCE

Systematic review of prospective cohort studies, Level II.

Clinical outcomes after anterior cruciate ligament injury: panther symposium ACL injury clinical outcomes consensus group

PURPOSE

A stringent outcome assessment is a key aspect for establishing evidence-based clinical guidelines for anterior cruciate ligament (ACL) injury treatment. The aim of this consensus statement was to establish what data should be reported when conducting an ACL outcome study, what specific outcome measurements should be used and at what follow-up time those outcomes should be assessed.

METHODS

To establish a standardized approach to assessment of clinical outcome after ACL treatment, a consensus meeting including a multidisciplinary group of ACL experts was held at the ACL Consensus Meeting Panther Symposium, Pittsburgh, PA; USA, in June 2019. The group reached consensus on nine statements by using a modified Delphi method.

RESULTS

In general, outcomes after ACL treatment can be divided into four robust categories-early adverse events, patient-reported outcomes, ACL graft failure/recurrent ligament disruption and clinical measures of knee function and structure. A comprehensive assessment following ACL treatment should aim to provide a complete overview of the treatment result, optimally including the various aspects of outcome categories. For most research questions, a minimum follow-up of 2 years with an optimal follow-up rate of 80% is necessary to achieve a comprehensive assessment. This should include clinical examination, any sustained re-injuries, validated knee-specific PROs and Health-Related Quality of Life questionnaires. In the mid- to long-term follow-up, the presence of osteoarthritis should be evaluated.

CONCLUSION

This consensus paper provides practical guidelines for how the aforementioned entities of outcomes should be reported and suggests the preferred tools for a reliable and valid assessment of outcome after ACL treatment.

LEVEL OF EVIDENCE

V.

Graft Choice for Anterior Cruciate Ligament Reconstruction With a Concomitant Non-surgically Treated Medial Collateral Ligament Injury Does Not Influence the Risk of Revision

PURPOSE

To compare the risk of anterior cruciate ligament (ACL) revision and the patient-reported outcome after ACL reconstruction with a concomitant non-surgically treated medial collateral ligament (MCL) injury with regard to 3 ACL graft choices; the use of semitendinosus (ST), the use of semitendinosus-gracilis (ST-G), and the use of patellar tendon (PT) autograft. It was hypothesized that the use of ST-G would be associated with a greater risk of ACL revision and poorer patient-reported knee function.

METHODS

Patients older than 15 years of age registered for a primary ACL reconstruction with a concomitant non-surgically treated MCL injury in the Swedish National Knee Ligament Registry were assessed for eligibility. Three groups were created according to ACL autograft choice; the ST, the ST-G, and the PT group. The primary outcomes were ACL revision and the 1- and 2-year Knee injury and Osteoarthritis Outcome Score (KOOS), including the KOOS patient acceptable symptom state (PASS). Cox regression analysis was applied to determine the proportional hazard ratio (HR) of primary ACL reconstruction survival. The KOOS was compared using the Mann-Whitney U test and Fisher exact test.

RESULTS

A total of 622 patients (mean age 29.7 years, 42.4% women) were included. There was no difference in the risk of ACL revision for either the ST group (HR 1.354; 95% confidence interval [CI] 0.678-2.702 or the PT group (HR 0.837; 95% CI 0.334-2.100), compared with the ST-G group. The ST group reported a greater mean 2-year KOOS sports and recreation (68.5, standard deviation [SD] 28.5) than the ST-G group (57.4 [SD 27.6], P = .010) and the PT group (54.1 [SD 30.3], P = .006). The ST group was superior in terms of achieving PASS in sports and recreation (55.3%; 95% CI 44.1-66.1%) compared with both the ST-G (37.4%; 95% CI 29.8-45.5%; P = .014) and the PT group (33.9%; 95% CI 22.1-47.4%; P = .009).

CONCLUSIONS

The risk of ACL revision did not differ between HT and PT autografts in patients undergoing ACL reconstruction with a non-surgically treated MCL injury. However, the use of ST-G was associated with poorer 2-year patient-reported knee function compared with the ST.

LEVEL OF EVIDENCE

Retrospective comparative trial, Level III.

Outcomes Following ACL Reconstruction Based on Graft Type: Are all Grafts Equivalent?

PURPOSE OF REVIEW

Anterior cruciate ligament reconstruction is one of the most common orthopedic procedures performed, accounting for over 200,000 cases annually. Despite the high prevalence, there is still much debate as to the optimal graft choice. The purpose of this review is to evaluate the current literature and discuss the reported outcomes for the most common graft choices.

RECENT FINDINGS

The most common autografts being used include bone-patellar tendon-bone (BPTB), hamstring tendon (HT), and quadriceps tendon (QT). Hamstring tendon might have a slightly higher re-tear rate when compared with BPTB (2.84 versus 2.80). However, BPTB has a higher rate of anterior knee and kneeling pain in the short- and mid-term follow-up. This has not been shown to be the case in long-term follow-up. Allograft is a viable option for revisions and primaries in patients greater than 35 years old; however, re-tear rate increases significantly in younger patients. ACL reconstruction graft choice is a highly studied and yet still exceedingly debated topic. Most large studies report either no significant difference or a small difference in failure rate and outcome scores between the different autograft choices. Allografts have been demonstrated to have an increased risk of failure in younger athletes and should be reserved for revision cases and those aged 35 years and older. Graft choice should ultimately be decided upon based on surgeon comfort and experience and individual patient characteristics.

Outcome After Anterior Cruciate Ligament Revision

PURPOSE OF REVIEW

To describe the current literature related to anterior cruciate ligament (ACL) revision in terms of surgical aspects, graft choices, concomitant injuries, patient-reported outcome, return to sport, and objective measurement outcome.

RECENT FINDINGS

An ACL rupture is a common knee injury, and the number of primary ACL reconstructions is increasing, implying a subsequent increase of ACL revisions in the future. It is widely accepted that an ACL revision is surgically challenging with a myriad of graft options to choose from. In many cases, simultaneous injuries to the index limb including meniscal and chondral lesions, respectively, are observed in the setting of a secondary ACL injury. Furthermore, the general understanding is that an ACL revision results in inferior outcome compared with a primary ACL reconstruction. Surgical treatment of an ACL revision can be performed as one-stage or two-stage procedure depending on, for example, the presence of limb malalignments, concomitant injuries, and tunnel widening. Nonirradiated allografts and autologous patella tendon, hamstring tendon, and quadriceps tendon are feasible options for ACL revision. Concomitant injuries to the affected knee such as intraarticular chondral lesions are more common in the setting of an ACL revision compared with primary ACL reconstruction while a lower presence of concomitant meniscal pathology is reported at ACL revision. Patients undergoing ACL revision have lower clinical and patient-reported outcome and lower rates of return to sport when compared with primary ACL surgery cases. However, long-term follow-ups with large study cohorts evaluating outcome of ACL revision are limited. Further research is needed to confirm the present findings of this review.