Poor functional performance 1 year after ACL reconstruction increases the risk of early osteoarthritis progression

Improved Quadriceps Torque Production With Optimized Biofeedback in Patients After Anterior Cruciate Ligament Reconstruction

Hogg, JA, Barger, NB, Bruce, JR, White, CC, Myer, GD, and Diekfuss, JA. Improved quadriceps torque production with optimized biofeedback in patients after anterior cruciate ligament reconstruction. J Strength Cond Res XX(X): 000–000, 2024—Optimizing performance through intrinsic motivation and attention for learning: prevention rehabilitation exercise play (OPTIMAL PREP) training strategies incorporate motor learning principles to enhance movement acquisition and retention. We aimed to use OPTIMAL PREP biofeedback to evaluate its potential to improve quadriceps and hamstring torque production in patients with anterior cruciate ligament reconstruction (ACL-R). Thirteen subjects 23 ± 19 months post ACL-R completed 5 concentric quadriceps/hamstrings repetitions on an isokinetic dynamometer for each limb and counterbalanced condition at 60°·s−1. For the control condition, subjects were instructed to perform the exercise “as hard and fast as possible.” For the OPTIMAL PREP condition, subjects were additionally told that “Research shows that if you focus on moving the line on the screen (external focus) you will exhibit greater quadriceps output (enhanced expectancies)” and were given the choice of graphical representation for the biofeedback (autonomy support). Quadriceps and hamstrings peak torque, rate of force development, and torque-angle waveforms were analyzed with 2 × 2 RMANOVAs (a priori >0.06). The ACL-R limb demonstrated increased quadriceps peak torque in the OPTIMAL PREP condition than in the control condition ( = 0.13, interaction p = 0.21, pairwise Cohen's d = 0.63). Anterior cruciate ligament reconstruction limb quadriceps deficits remained near terminal extension (14–45°; peak Cohen's d = 0.57, p < 0.001). For hamstrings peak torque, we observed moderate effects for condition (OPTIMAL PREP greater; = 0.10, p = 0.29) and limb (uninvolved greater; = 0.13, p = 0.22). Easily implementable OPTIMAL PREP training strategies improved ACL-R limb quadriceps torque production, resulting in between-limb parity. However, asymmetries still existed near terminal extension.

An 8-week physiotherapist-led return to sport group program after anterior cruciate ligament reconstruction improves measures of physical and psychological function: A case series

BACKGROUND

Low return to competitive sport, high reinjury rates and long-term functional impairment of anterior cruciate ligament reconstruction (ACLR) present significant challenges for patients. A program that facilitates a safe return to sport (RTS) following ACLR could potentially improve outcomes.

STUDY DESIGN

Case Series.

METHODS

Sixty participants (median 20-years-old (13-36), 43 males, 18 females, median 7.5 months (4-25) post-ACLR) completed an eight-week exercise program. A battery of physical tests and patient-reported outcome measures were assessed pre and post-program. The number of participants passing RTS criteria was evaluated, and RTS rates were determined. The correlation between the ACL-RSI and measures of physical function was explored.

RESULTS

Improvements in all isometric strength, hop tests, running T-test, and patient reported outcome measures were seen post-program. Five (8%) participants successfully passed all RTS criteria and eighty-five percent of participants returned to their previous level of sport. The ACL-RSI and the IKDC showed correlation across all time points (pre rs = 0.49; post rs = 0.40; change r = 0.40).

CONCLUSIONS

Our study demonstrated improvements in all RTS criteria tests upon completing the 8-week rehabilitation program; however, few participants (8%) passed all RTS criteria. Psychological readiness is more closely related to patient-reported function than functional tests.

Functional Return-to-Sport Testing Demonstrates Inconsistency in Predicting Short-Term Outcomes Following Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To systematically review the relationship between functional testing at the time of return to sport (RTS) and short-term outcomes, such as second anterior cruciate ligament (ACL) tear and return to a preinjury level of sport, among athletes who underwent anterior cruciate ligament reconstruction (ACLR).

METHODS

A systematic literature search was performed in MEDLINE, EMBASE, Scopus, and Web of Science to identify studies examining athletes who underwent functional RTS testing and were followed for at least 12 months following ACLR. Studies were screened by 2 reviewers. A standardized template was used to extract information regarding study characteristics, ACLR information, functional test results, and risk factors associated with retear or reduced RTS.

RESULTS

Of the 937 studies identified, 22 met the inclusion criteria. The average time between ACLR and RTS testing was 8.5 months. Single leg hop for distance performance had no association with retear risk in any study and no association with RTS rates in most studies. Quadriceps strength had conflicting results in relation to retear risk, whereas it had no relationship with RTS rates. Rates of reinjury and RTS were similar between patients who passed and did not pass combined hop and strength batteries. Asymmetric knee extension and hip moments, along with increased knee valgus and knee flexion angles, demonstrated increased risk of retear.

CONCLUSIONS

Individual hop and strength tests that are often used in RTS protocols following ACLR may have limited and inconsistent value in predicting ACL reinjury and reduced RTS when used in isolation. Combined hop and strength test batteries also demonstrate low sensitivity and negative predictive value, highlighting conflicting evidence to suggest RTS testing algorithm superiority.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I-IV studies.

Association between hip muscle strength/function and hip cartilage defects in sub-elite football players with hip/groin pain

OBJECTIVE

To explore associations between hip muscle strength and cartilage defects (presence and severity) on magnetic resonance imaging (MRI) in young adults with hip/groin pain participating in sub-elite football.

DESIGN

Sub-elite football players with hip/groin pain (>6 months) completed assessments of isometric hip strength and functional task performance. Hip cartilage defects were assessed using the Scoring Hip Osteoarthritis with MRI tool. This exploratory, cross-sectional study used logistic and negative binomial models to assess the relationships between hip muscle strength or functional task performance and hip cartilage defects, controlling for body mass index, age, testing site and cam morphology, incorporating sex-specific interaction terms.

RESULTS

One hundred and eighty-two (37 women) sub-elite (soccer or Australian football) players with hip/groin pain (age 26 ± 7 years) were included. Greater hip extension strength was associated with higher cartilage total score (adjusted incidence rate ratio [aIRR] 1.01, 95%CI: 1.0 to 1.02, p = 0.013) and superolateral cartilage score (adjusted odds ratio (aOR) 1.03, 95% confidence interval (CI): 1.01 to 1.06, p < 0.01). In female sub-elite football players, greater hip external rotation strength was associated with lateral cartilage defects (aOR 1.61, 95%CI: 1.05 to 2.48, p = 0.03) and higher cartilage total score (aIRR 1.25, 95%CI: 1.01 to 1.66, p = 0.042). A one-repetition increase in one-leg rise performance was related to lower odds of superomedial cartilage defects (aOR 0.96, 95%CI: 0.94 to 0.99, p < 0.01).

CONCLUSIONS

Overall, there were few associations between peak isometric hip muscle strength and overall hip cartilage defects. It is possible that other factors may have relevance in sub-elite football players. Additional studies are needed to support or refute our findings that higher one leg rise performance was associated with reduced superomedial cartilage defect severity and greater hip extension strength was related to higher cartilage defect severity scores.

Either Autonomy Support or Enhanced Expectancies Delivered Via Virtual-Reality Benefits Frontal-Plane Single-Leg Squatting Kinematics

Our purpose in this study was to determine the effects of a virtual reality intervention delivering specific motivational motor learning manipulations of either autonomy support (AS) or enhanced expectancies (EE) on frontal plane single-leg squatting kinematics. We allocated 45 participants (21 male, 24 female) demonstrating knee, hip, and trunk frontal plane mechanics associated with elevated anterior cruciate ligament injury risk to one of three groups (control, AS, or EE). Participants mimicked an avatar performing five sets of eight repetitions of exemplary single-leg squats. AS participants were given the added option of choosing the color of their avatar. EE participants received real-time biofeedback in the form of green highlights on the avatar that remained on as long as the participant maintained pre-determined 'safe' frontal plane mechanics. We measured peak frontal plane knee, hip, and trunk angles before (baseline) and immediately following (post) the intervention. The control group demonstrated greater increases in knee abduction angle (Δ = +2.3°) than did the AS (Δ = +0.1°) and EE groups (Δ = -0.4°) (p = .003; η2p = .28). All groups demonstrated increased peak hip adduction (p = .01, ηp2 = .18) (control Δ = +1.5°; AS Δ = +3.2°; EE Δ = +0.7°). Hip adduction worsened in all groups. AS and EE motivation strategies appeared to mitigate maladaptive frontal plane knee mechanics.

Recruitment and baseline characteristics of young adults at risk of early-onset knee osteoarthritis after ACL reconstruction in the SUPER-Knee trial

Objectives

The study aims to (1) report the process of recruiting young adults into a secondary knee osteoarthritis prevention randomised controlled trial (RCT) after anterior cruciate ligament reconstruction (ACLR); (2) determine the number of individuals needed to be screened to include one participant (NNS) and (3) report baseline characteristics of randomised participants.

Methods

The SUpervised exercise-therapy and Patient Education Rehabilitation (SUPER)-Knee RCT compares SUPER and minimal intervention for young adults (aged 18-40 years) with ongoing symptoms (ie, mean score of <80/100 from four Knee injury and Osteoarthritis Outcome Score subscales (KOOS4)) 9-36 months post-ACLR. The NNS was calculated as the number of prospective participants screened to enrol one person. At baseline, participants provided medical history, completed questionnaires (demographic, injury/surgery, rehabilitation characteristics) and underwent physical examination.

Results

1044 individuals were screened to identify 567 eligible people, from which 184 participants (63% male) enrolled. The sample of enrolled participants was multicultural (29% born outside Australia; 2% Indigenous Australians). The NNS was 5.7. For randomised participants, mean±SD age was 30±6 years. The mean body mass index was 27.3±5.2 kg/m2, with overweight (43%) and obesity (21%) common. Participants were, on average, 2.3 years post-ACLR. Over half completed <8 months of postoperative rehabilitation, with 56% having concurrent injury/surgery to meniscus and/or cartilage. The most affected KOOS (0=worst, 100=best) subscale was quality of life (mean 43.7±19.1).

Conclusion

Young adults post-ACLR were willing to participate in a secondary osteoarthritis prevention trial. Sample size calculations should be multiplied by at least 5.7 to provide an estimate of the NNS. The SUPER-Knee cohort is ideally positioned to monitor and intervene in the early development and trajectory of osteoarthritis.

Trial registration number

ACTRN12620001164987.

Injury prevention for women and girls playing Australian Football: programme cocreation, dissemination and early adopter coach feedback

Background

Adherence to injury prevention programmes may improve with greater end-user involvement and application of implementation frameworks during development. We describe the cocreation, initial dissemination and feedback from programme early adopters (coaches), to develop the first evidence-informed injury prevention programme for women playing community Australian Football (Prep-to-Play).

Methods

We used a pragmatic seven-step process for developing sports injury prevention programmes to (1) gain organisational support, (2) compile research evidence, (3) consult experts, (4) engage end-users, (5) test programme acceptability, (6) evaluate against theory and (7) gain early adopter feedback. All Australian Football-registered coaches of women's/girls' teams were sent a postseason survey to determine initial awareness, adoption and implementation (steps 5 and 6). Purposively selected coaches were invited to interviews/focus groups (step 7) to identify competency, organisational and leadership implementation drivers with a deductive thematic analysis applied.

Results

Prep-to-Play was cocreated using previous efficacious programmes and expert input (steps 1-4), and disseminated via the national sporting organisation in preseason 2019 to all registered coaches (step 5). 343 coaches (90 women) completed the postseason survey and 22 coaches (5 women) participated in an interview (n=9) or focus group (n=13) (steps 6 and 7). 268 coaches (78%) were aware of Prep-to-Play. Of those aware, 218 (81%) had used (at least one element) Prep-to-Play, and 143 (53%) used it at least twice per week. Competency drivers included local expert-delivered face-to-face workshops complimented by online content and ongoing support. Organisational drivers included coach education integrated into existing league/club. Leadership drivers included compulsory injury prevention education integrated into coach reaccreditation processes or incentivisation via recognition (eg, professional development points).

Conclusions

Cocreation and organisational support resulted in high programme awareness and adoption. However, high fidelity implementation and maintenance may need to be facilitated by competency, organisational and leadership drivers. Responsibility should be shared among all stakeholders.

Video Analysis of Anterior Cruciate Ligament Injuries in Male Professional Basketball Players: Injury Mechanisms, Situational Patterns, and Biomechanics

Background

Improving our understanding of the situations and biomechanics that result in an anterior cruciate ligament (ACL) injury in basketball players may support the design of more effective programs to mitigate the risk of injury.

Purpose

To (1) describe the mechanisms, situational patterns, and gross biomechanics (kinematics) of ACL injuries in professional basketball matches using video analysis and (2) document the distribution of ACL injuries according to player position, phase of the match, and location on the court.

Study Design

Case series; Level of evidence, 4.

Methods

A total of 38 ACL injuries in professional male European basketball leagues from the 2013-2014 to 2019-2020 seasons were identified. There were 36 (95%) injury videos analyzed for injury mechanisms and situational patterns, while biomechanical analysis was possible in 32 cases. Overall, 3 independent reviewers evaluated each video. Data according to player position (n = 38), phase of the match (n = 38), and location on the court (n = 36) were evaluated.

Results

More injuries occurred while attacking (n = 25 [69%]) than defending (n = 11 [31%]). There was 1 (3%) direct contact injury, 21 (58%) indirect contact injuries, and 14 (39%) noncontact injuries. Most injuries (83%) occurred during 3 main situations: offensive cut (n = 17 [47%]), landing from a jump (n = 8 [22%]), and defensive cut (n = 5 [14%]). Injuries generally involved knee flexion (with minimal hip/trunk flexion and reduced plantarflexion) in the sagittal plane and knee valgus loading in most cases (75%). A similar number of injuries occurred during the first (53%) and second (47%) halves of the match, with a higher prevalence in the second (37%) and fourth (34%) quarters. Half of the injuries occurred during the first 10 minutes of effective playing time. More injuries occurred in guards (58%), and 73% of all injuries occurred in the scoring zone.

Conclusion

Indirect contact was the main injury mechanism found in male professional basketball players. The offensive cut was the most common situational pattern. Biomechanical analysis confirmed a multiplanar mechanism, with knee loading in the sagittal plane accompanied by dynamic valgus. More injuries occurred in the first 10 minutes of a player's effective playing time, within the scoring zone, and among guards.

Optimising the Early-Stage Rehabilitation Process Post-ACL Reconstruction

Outcomes following anterior cruciate ligament reconstruction (ACLR) need improving, with poor return-to-sport rates and a high risk of secondary re-injury. There is a need to improve rehabilitation strategies post-ACLR, if we can support enhanced patient outcomes. This paper discusses how to optimise the early-stage rehabilitation process post-ACLR. Early-stage rehabilitation is the vital foundation on which successful rehabilitation post-ACLR can occur. Without high-quality early-stage (and pre-operative) rehabilitation, patients often do not overcome major aspects of dysfunction, which limits knee function and the ability to transition through subsequent stages of rehabilitation optimally. We highlight six main dimensions during the early stage: (1) pain and swelling; (2) knee joint range of motion; (3) arthrogenic muscle inhibition and muscle strength; (4) movement quality/neuromuscular control during activities of daily living (5) psycho-social-cultural and environmental factors and (6) physical fitness preservation. The six do not share equal importance and the extent of time commitment devoted to each will depend on the individual patient. The paper provides recommendations on how to implement these into practice, discussing training planning and programming, and suggests specific screening to monitor work and when the athlete can progress to the next stage (e.g. mid-stage rehabilitation entry criteria).

Muscle strength and osteoarthritis of the knee: a systematic review and meta-analysis of longitudinal studies

OBJECTIVE

To evaluate the sex-specific association between low knee extensor and flexor muscle strength and the risk of knee structural worsening.

MATERIALS AND METHODS

Systematic searches in five databases identified longitudinal studies (≥ 1 year follow-up) reporting an association between knee extensor or flexor strength and structural decline in individuals with, or at risk of, knee osteoarthritis. Results were pooled for tibiofemoral and patellofemoral osteoarthritis worsening (and stratified by sex/gender where possible) using a random-effects meta-analysis estimating the risk ratio and 95% confidence interval or a best-evidence synthesis. Risk of bias and overall certainty of evidence were assessed.

RESULTS

Fourteen studies were included with participants (mean age 27-72 years) with osteoarthritis (n = 8), at risk of osteoarthritis (n = 3), or a combination with, or at risk of, osteoarthritis (n = 3). Low knee extensor strength was associated with an increased risk of worsening tibiofemoral (12 studies: RR 1.18, 95% CI 1.04 to 1.35) and patellofemoral osteoarthritis (4 studies: RR 1.62, 95% CI 1.01 to 2.61). Significant associations between low knee extensor strength and worsening tibiofemoral osteoarthritis were observed for women (4 studies: RR 1.25, 95% CI 1.04 to 1.51) but not men (4 studies: RR 1.10, 95% CI 0.87 to 1.39). Low knee flexor strength increased the risk of worsening tibiofemoral osteoarthritis (5 studies: RR 1.16, 95% CI 1.07 to 1.26). Ten studies were high risk of bias, and all estimates were graded as very low certainty of evidence.

CONCLUSION

Low knee extensor and flexor strength increased the risk of worsening tibiofemoral osteoarthritis. Low knee extensor strength increased the risk of worsening patellofemoral osteoarthritis. The relationship between low knee extensor strength and worsening tibiofemoral osteoarthritis may be modified by sex/gender.

Functional leg performance 2 years after ACL surgery: a comparison between InternalBrace™-augmented repair versus reconstruction versus healthy controls

BACKGROUND

While clinical and patient-reported outcomes have been investigated in patients after InternalBrace™-augmented anterior cruciate ligament repair (ACL-IB), less is known regarding restoration of functional performance. We aimed to determine differences in functional performance within and between patients 2 years after ACL-IB, patients 2 years after ACL reconstruction (ACL-R), and healthy controls.

MATERIALS AND METHODS

A total of 29 ACL-IB, 27 ACL-R (hamstring autograft), and 29 controls performed single-leg hop (maximum forward distance hop, SLH; side hop > 40 cm in 30 s, SH), proprioception (knee joint position sense at 30° and 60° flexion), and dynamic postural balance (Y Balance) tests. Differences were calculated within groups (side-to-side difference) and between the involved leg of patients and the non-dominant leg of controls, and were evaluated to predefined statistical (P < 0.05), clinically relevant, and methodological (smallest detectable change) thresholds. The number of exceeded thresholds represented no (0), small (1), moderate (2), or strong (3) differences. In addition, the relative number of participants achieving leg symmetry (≥ 90%) and normal performance (≥ 90% of the average performance of the non-dominant leg of controls) were compared between groups (chi-squared tests, P < 0.05).

RESULTS

We observed no-to-moderate leg differences within ACL-IB (moderate difference in hops) and within ACL-R (moderate difference in knee proprioception), no leg differences between patient groups, no-to-small leg differences between ACL-IB and controls, and no leg differences between ACL-R and controls in functional performance. However, two patients in ACL-IB and ACL-R, respectively, passed the hop pretest only with their uninvolved leg, and fewer patients after ACL-IB and ACL-R than controls reached a leg symmetry and normal leg performance of controls in SLH (P < 0.001).

CONCLUSIONS

Functional performance seems to be comparable 2 years postoperatively between ACL-IB and ACL-R for a specific subgroup of patients (i.e., proximal ACL tears, moderate activity level). However, the presumed advantage of comparable functional outcome with preserved knee structures after augmented ACL repair compared with ACL-R, and the tendency of both patient groups toward leg asymmetry and compromised single-leg hop performance in the involved legs, warrants further investigation. Level of Evidence Level III, case-control study. Trial registration clinicaltrials.gov, NCT04429165 (12/09/2020). Prospectively registered, https://clinicaltrials.gov/ct2/show/NCT04429165 .

Clinically Relevant Subgroups Among Athletes Who Have Ruptured Their Anterior Cruciate Ligaments: A Delaware-Oslo Cohort Study

OBJECTIVE

To identify subgroups of individuals with anterior cruciate ligament (ACL) injuries based on patient characteristics, self-reported outcomes, and functional performance at baseline, and to associate subgroups with long-term outcomes after ACL rupture.

METHODS

A total of 293 participants (45.7% male, mean ± SD age 26.2 ± 9.4 years, days from injury 58 ± 35) were enrolled after effusion, pain, and range of motion impairments were resolved and quadriceps strength was at least 70% of the uninvolved limb. Mixture modeling was used to uncover latent subgroups without a prior group classification using probabilistic assignment. Variables include demographics, functional testing, and self-reported outcome measures. Radiographic evidence of osteoarthritis (OA; i.e., Kellgren/Lawrence grade of ≥1) in the involved knee at 5 years after injury was the primary outcome of interest. Chi-square tests assessed differences in the presence of radiographic OA in the involved knee between subgroups at 5 years after ACL rupture. Secondary outcomes of interest included radiographic OA in the uninvolved knee, return to preinjury sport by 2 years, operative status, and clinical OA (classified using Luyten et al criteria) at 5 years.

RESULTS

Four distinct subgroups exist after ACL rupture (younger good self-report, younger poor self-report, older poor self-report, older good self-report) with 30%, 31%, 47%, and 53%, respectively, having involved knee OA. The percentage of radiographic OA was not significantly different between the groups (P = 0.059).

CONCLUSION

The prevalence of OA in all subgroups is highly concerning. These results suggest there are unique subgroupings of individuals that may guide treatment after ACL rupture and reconstruction by providing support for developing a patient-centered approach.

Does the one-leg rise test reflect quadriceps strength in individuals following anterior cruciate ligament reconstruction?

OBJECTIVE

To explore if one-leg rise test performance is associated with quadriceps strength following anterior cruciate ligament reconstruction (ACLR).

DESIGN

Cross-sectional.

PARTICIPANTS

100 individuals (50 females, 50 males) aged 18-40 years, 9-36 months post-ACLR with ongoing knee symptoms (KOOS4 <80/100).

MAIN OUTCOME MEASURES

Number of one-leg rise repetitions (using an adjustable-height plinth) and isometric quadriceps strength using isokinetic dynamometry (60° flexion, normalised to body mass). Multivariable fractional polynomial regression models adjusted for sex explored relationships between one-leg rise performance (repetitions) and quadriceps strength (Nm/kg) for each limb.

RESULTS

A non-linear, increasing association between one-leg rise performance and quadriceps strength was observed, with the rate of increase attenuating at higher values of one-leg rise performance. Similar relationships were observed in the ACLR (β = 0.15, 95%CI 0.10 to 0.20; adjusted r2 = 0.51) and contralateral limb (β = 0.14, 95%CI 0.08 to 0.19; r2 = 0.42).

CONCLUSION

The one-leg rise test can be an indicator of quadriceps strength in individuals after ACLR, enabling clinicians to easily monitor quadriceps strength recovery without specialised equipment. With the relationship between one-leg rise performance and quadriceps strength attenuating with a larger number of one-leg rises achieved, other factors (e.g., motivation, endurance) likely contribute to one-leg rise performance at higher values.

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.

The Relationship of Knee-related Quality of Life With Function, Psychological Factors, Strength, Performance, and Postural Stability After ACL Reconstruction: A Cross-Sectional Study

BACKGROUND

Patients after anterior cruciate ligament reconstruction (ACLR) have decreased health-related quality of life (QoL) compared with healthy control participants. Few studies have verified the predictors of QoL using Quality of Life Outcome Measure Questionnaire for Chronic Anterior Cruciate Ligament Deficiency (ACL-QoL), and no study has verified the relationship of psychological factors and knee function with ACL-QoL in patients after ACLR.

HYPOTHESIS

Knee functional status, muscle strength, performance in hop tests, postural stability, and psychological factors would be the predictors of QoL after ACLR.

STUDY DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE

Level 4.

METHODS

A total of 131 participants who had undergone ACLR at least 6 months previously were evaluated. QoL was assessed using ACL-QoL; knee functional status, using International Knee Documentation Committee Subjective Knee (IKDC) and global rating scale (GRS); psychological readiness, using Anterior Cruciate Ligament Return to Sport after Injury Scale (ACL-RSI); kinesiophobia, using Tampa Scale for Kinesiophobia (TSK-17); knee strength, using isokinetic dynamometer; performance, using single-leg hop tests; and postural stability, using Biodex Balance System. Pearson's linear correlation and stepwise hierarchical multiple linear regression analyses were performed to verify the predictors of QoL.

RESULTS

ACL-QoL showed a moderate correlation with IKDC (r = 0.69), GRS (r = 0.55), ACL-RSI (r = 0.50), and TSK-17 (r = -0.49). ACL-QoL presented none to low correlations with the variables of muscle strength, postural stability, and performance in hop tests. The variables related to the knee functional status and psychological factors (IKDC, GRS, ACL-RSI, and TSK-17) were found to be the predictors of QoL (R2 = 0.56; P = 0.01).

CONCLUSION

Knee functional status, psychological readiness, and kinesiophobia were the predictors of knee-related QoL in patients after ACLR.

CLINICAL RELEVANCE

These results can assist clinicians in the therapeutic monitoring of the factors that may interfere with QoL in patients after ACLR.

Trajectory of knee health in runners with and without heightened osteoarthritis risk: the TRAIL prospective cohort study protocol

INTRODUCTION

Running is one of the most popular recreational activities worldwide, due to its low cost and accessibility. However, little is known about the impact of running on knee joint health in runners with and without a history of knee surgery. The primary aim of this longitudinal cohort study is to compare knee joint structural features on MRI and knee symptoms at baseline and 4-year follow-up in runners with and without a history of knee surgery. Secondary aims are to explore the relationships between training load exposures (volume and/or intensity) and changes in knee joint structure and symptoms over 4 years; explore the relationship between baseline running biomechanics, and changes in knee joint structure and symptoms over 4 years. In addition, we will explore whether additional variables confound, modify or mediate these associations, including sex, baseline lower-limb functional performance, knee muscle strength, psychological and sociodemographic factors.

METHODS AND ANALYSIS

A convenience sample of at least 200 runners (sex/gender balanced) with (n=100) and without (n=100) a history of knee surgery will be recruited. Primary outcomes will be knee joint health (MRI) and knee symptoms (baseline; 4 years). Exposure variables for secondary outcomes include training load exposure, obtained daily throughout the study from wearable devices and three-dimensional running biomechanics (baseline). Additional variables include lower limb functional performance, knee extensor and flexor muscle strength, biomarkers, psychological and sociodemographic factors (baseline). Knowledge and beliefs about osteoarthritis will be obtained through predefined questions and semi-structured interviews with a subset of participants. Multivariable logistic and linear regression models, adjusting for potential confounding factors, will explore changes in knee joint structural features and symptoms, and the influence of potential modifiers and mediators.

ETHICS AND DISSEMINATION

Approved by the La Trobe University Ethics Committee (HEC-19524). Findings will be disseminated to stakeholders, peer-review journals and conferences.

Unilateral tests of lower-limb function as prognostic indicators of future knee-related outcomes following anterior cruciate ligament injury: a systematic review and meta-analysis of 13 150 adolescents and adults

OBJECTIVE

To investigate the prognostic capacity of individual hop tests, hop test batteries and other unilateral functional performance tests following anterior cruciate ligament (ACL) injury.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

Six databases searched up to June 2021.

ELIGIBILITY CRITERIA

Studies reporting associations between unilateral lower-limb function (eg, hop tests) following ACL injury and future (≥3 months) knee-related outcomes.

RESULTS

Of 42 included studies (13 150 participants), all assessed the single-forward hop test and 32 assessed a repeated-forward hop test (crossover hop, triple hop, 6m-timed hop), mostly within a year after ACL injury/reconstruction. Results of meta-analyses indicated that higher single-forward and repeated-forward hop limb symmetry were associated with higher odds of return-to-sport 1-3 years post-ACL reconstruction (OR 2.15; 95% CI 1.30 to 3.54; OR 2.11; 95% CI 1.23 to 3.60, respectively). Higher single-forward and repeated-forward hop limb symmetry was associated with better self-reported symptoms and function 1-37 years after ACL injury (OR 2.51; 95% CI 1.62 to 3.88; OR 4.28; 95% CI 1.65 to 11.08, respectively). Higher limb symmetry on a repeated-forward hop does not appear to be associated with higher odds of successful rehabilitation without ACL reconstruction (OR 1.51; 95% CI 0.94 to 2.44). Achieving ≥90% limb symmetry on the single-forward hop was associated with reduced odds of knee osteoarthritis 5-37 years after ACL injury (OR 0.46; 95% CI 0.23 to 0.94).

CONCLUSION

Very low certainty evidence suggests single-forward and repeated-forward hop tests are prognostic indicators for important knee-related outcomes in individuals after ACL injury and may help stratify individuals at risk of poor outcomes to target rehabilitation interventions.

PROSPERO REGISTRATION NUMBER

CRD42018092197.

SUpervised exercise-therapy and Patient Education Rehabilitation (SUPER) versus minimal intervention for young adults at risk of knee osteoarthritis after ACL reconstruction: SUPER-Knee randomised controlled trial protocol

INTRODUCTION

Anterior cruciate ligament injury and reconstruction (ACLR) is often associated with pain, functional loss, poor quality of life and accelerated knee osteoarthritis development. The effectiveness of interventions to enhance outcomes for those at high risk of early-onset osteoarthritis is unknown. This study will investigate if SUpervised exercise-therapy and Patient Education Rehabilitation (SUPER) is superior to a minimal intervention control for improving pain, function and quality of life in young adults with ongoing symptoms following ACLR.

METHODS AND ANALYSIS

The SUPER-Knee Study is a parallel-group, assessor-blinded, randomised controlled trial. Following baseline assessment, 184 participants aged 18-40 years and 9-36 months post-ACLR with ongoing symptoms will be randomly allocated to one of two treatment groups (1:1 ratio). Ongoing symptoms will be defined as a mean score of <80/100 from four Knee injury and Osteoarthritis Outcome Score (KOOS₄) subscales covering pain, symptoms, function in sports and recreational activities and knee-related quality of life. Participants randomised to SUPER will receive a 4-month individualised, physiotherapist-supervised strengthening and neuromuscular programme with education. Participants randomised to minimal intervention (ie, control group) will receive a printed best-practice guide for completing neuromuscular and strengthening exercises following ACLR. The primary outcome will be change in the KOOS₄ from baseline to 4 months with a secondary endpoint at 12 months. Secondary outcomes include change in individual KOOS subscale scores, patient-perceived improvement, health-related quality of life, kinesiophobia, physical activity, thigh muscle strength, knee function and knee cartilage morphology (ie, lesions, thickness) and composition (T2 mapping) on MRI. Blinded intention-to-treat analyses will be performed. Findings will also inform cost-effectiveness analyses.

ETHICS AND DISSEMINATION

This study is approved by the La Trobe University and Alfred Hospital Ethics Committees. Results will be presented in peer-reviewed journals and at international conferences.

TRIAL REGISTRATION NUMBER

ACTRN12620001164987.

FUNCTIONAL EXERCISE ON PATIENTS AFTER SPORTS MENISCUS INJURY

ABSTRACT Introduction Knee meniscus injury is a common sports injury, and minimally invasive surgery under knee arthroscopy has become an ideal method to treat meniscus injuries. This surgery rehabilitation has been improved, and several studies on the effects of functional exercise in the range of treatment are still inconclusive. Objective Study the functional exercise rehabilitation effects in patients after sports meniscus injury. Methods Twenty patients with meniscus-medial injury being operated on were selected, including eight men and 12 women. They were randomly divided into neuromuscular and strength training groups (11). Signs and symptoms were assessed before and eight weeks after treatment. JOA score indices and gait tests were compared. The impact of rehabilitation differences was evaluated in each group. Results Eight weeks after rehabilitation in both groups, the scores of the strength training group were higher than the neuromuscular group; the difference between the groups was statistically significant (P<0.05). Conclusion Functional exercise accelerates joint recovery, reflected in increased strength of adjacent muscles. The muscle and joint training effects on postoperative meniscus injury are worthy of recognition. The baropodometry revealed distinctions in walking patterns between different rehabilitation methods. From the perspective of this research, rehabilitation methods combined with proprioceptive exercises are complementary. Evidence Level II; Therapeutic Studies - Investigating the result.

Risk factors of cartilage lesion after anterior cruciate ligament reconstruction

Anterior cruciate ligament injury is the most common sports injury in orthopaedics, which can adversely affect knee joint function and exercise of patients. Using arthroscopy to reconstruct the anterior cruciate ligament has become the first choice for treating anterior cruciate ligament rupture. However, different degrees of articular cartilage injury of the knee can be observed in patients after anterior cruciate ligament reconstruction. More importantly, the articular cartilage injury after anterior cruciate ligament reconstruction indicates that it will develop into osteoarthritis in the long term. It is of great significance to fully understand the factors that lead to the occurrence and development of cartilage injury. This article reviews the effects of surgical methods, meniscus status, different grafts, time from injury to surgical intervention, postoperative knee joint stability, postoperative rehabilitation, knee joint anatomical factors, and demographic characteristics of patients on articular cartilage degeneration after anterior cruciate ligament reconstruction. The present review provides insights into the anterior cruciate ligament reconstruction, which can be used to investigate new treatment strategies to delay and prevent the progress of osteoarthritis. At the same time, it provides a holistic understanding of the influence of multiple factors on cartilage lesions after anterior cruciate ligament reconstruction.

Subject-specific biomechanical analysis to estimate locations susceptible to osteoarthritis-Finite element modeling and MRI follow-up of ACL reconstructed patients

The aims of this case-control study were to: (1) Identify cartilage locations and volumes at risk of osteoarthritis (OA) using subject-specific finite element (FE) models; (2) Quantify the relationships between the simulated biomechanical parameters and T₂ and T_1ρ relaxation times of magnetic resonance imaging (MRI). We created subject-specific FE models for seven patients with anterior cruciate ligament (ACL) reconstruction and six controls based on a previous proof-of-concept study. We identified locations and cartilage volumes susceptible to OA, based on maximum principal stresses and absolute maximum shear strains in cartilage exceeding thresholds of 7 MPa and 32%, respectively. The locations and volumes susceptible to OA were compared qualitatively and quantitatively against 2-year longitudinal changes in T₂ and T_1ρ relaxation times. The degeneration volumes predicted by the FE models, based on excessive maximum principal stresses, were significantly correlated (r = 0.711, p < 0.001) with the degeneration volumes determined from T₂ relaxation times. There was also a significant correlation between the predicted stress values and changes in T₂ relaxation time (r = 0.649, p < 0.001). Absolute maximum shear strains and changes in T_1ρ relaxation time were not significantly correlated. Five out of seven patients with ACL reconstruction showed excessive maximum principal stresses in either one or both tibial cartilage compartments, in agreement with follow-up information from MRI. Expectedly, for controls, the FE models and follow-up information showed no degenerative signs. Our results suggest that the presented modelling methodology could be applied to prospectively identify ACL reconstructed patients at risk of biomechanically driven OA, particularly by the analysis of maximum principal stresses of cartilage.

Rehabilitation after anterior cruciate ligament and meniscal injuries: a best-evidence synthesis of systematic reviews for the OPTIKNEE consensus

OBJECTIVE

Synthesise evidence for effectiveness of rehabilitation interventions following ACL and/or meniscal tear on symptomatic, functional, clinical, psychosocial, quality of life and reinjury outcomes.

DESIGN

Overview of systematic reviews with Grading of Recommendations Assessment, Development and Evaluation certainty of evidence.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, SPORTDiscus and Cochrane Library.

ELIGIBILITY CRITERIA

Systematic reviews of randomised controlled trials investigating rehabilitation interventions following ACL and/or meniscal tears in young adults.

RESULTS

We included 22 systematic reviews (142 trials of mostly men) evaluating ACL-injured individuals and none evaluating isolated meniscal injuries. We synthesised data from 16 reviews evaluating 12 different interventions. Moderate-certainty evidence was observed for: (1) neuromuscular electrical stimulation to improve quadriceps strength; (2) open versus closed kinetic chain exercises to be similarly effective for quadriceps strength and self-reported function; (3) structured home-based versus structured in-person rehabilitation to be similarly effective for quadriceps and hamstring strength and self-reported function; and (4) postoperative knee bracing being ineffective for physical function and laxity. There was low-certainty evidence that: (1) preoperative exercise therapy improves self-reported and physical function postoperatively; (2) cryotherapy reduces pain and analgesic use; (3) psychological interventions improve anxiety/fear; and (4) whole body vibration improves quadriceps strength. There was very low-certainty evidence that: (1) protein-based supplements improve quadriceps size; (2) blood flow restriction training improves quadriceps size; (3) neuromuscular control exercises improve quadriceps and hamstring strength and self-reported function; and (4) continuous passive motion has no effect on range of motion.

CONCLUSION

The general level of evidence for rehabilitation after ACL or meniscal tear was low. Moderate-certainty evidence indicates that several rehabilitation types can improve quadriceps strength, while brace use has no effect on knee function/laxity.

What tests should be used to assess functional performance in youth and young adults following anterior cruciate ligament or meniscal injury? A systematic review of measurement properties for the OPTIKNEE consensus

OBJECTIVES

To critically appraise and summarise measurement properties of functional performance tests in individuals following anterior cruciate ligament (ACL) or meniscal injury.

DESIGN

Systematic review.

DATA SOURCES

Systematic searches were performed in Medline (Ovid), Embase (Ovid), CINAHL (EBSCO) and SPORTSDiscus (EBSCO) on 7 July 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies evaluating at least one measurement property of a functional performance test including individuals following an ACL tear or meniscal injury with a mean injury age of ≤30 years. The COnsensus-based Standards for the selection of health Measurement INstruments Risk of Bias checklist was used to assess methodological quality. A modified Grading of Recommendations Assessment, Development and Evaluation assessed evidence quality.

RESULTS

Thirty studies evaluating 26 functional performance tests following ACL injury were included. No studies were found in individuals with an isolated meniscal injury. Included studies evaluated reliability (n=5), measurement error (n=3), construct validity (n=26), structural validity (n=1) and responsiveness (n=1). The Single Leg Hop and Crossover Hop tests showed sufficient intrarater reliability (high and moderate quality evidence, respectively), construct validity (low-quality and moderate-quality evidence, respectively) and responsiveness (low-quality evidence).

CONCLUSION

Frequently used functional performance tests for individuals with ACL or meniscal injury lack evidence supporting their measurement properties. The Single Leg Hop and Crossover Hop are currently the most promising tests following ACL injury. High-quality studies are required to facilitate stronger recommendations of performance-based outcomes following ACL or meniscal injury.

Early Superimposed NMES Training is Effective to Improve Strength and Function Following ACL Reconstruction with Hamstring Graft regardless of Tendon Regeneration

The study aimed at investigating the effects of neuromuscular electrical stimulation superimposed on functional exercises (NMES+) early after anterior cruciate ligament reconstruction (ACLr) with hamstring graft, on muscle strength, knee function, and morphology of thigh muscles and harvested tendons. Thirty-four participants were randomly allocated to either NMES+ group, who received standard rehabilitation with additional NMES of knee flexor and extensor muscles, superimposed on functional movements, or to a control group, who received no additional training (NAT) to traditional rehabilitation. Participants were assessed 15 (T1), 30 (T2), 60 (T3), 90 (T4) and at a mean of 380 days (T5) after ACLr. Knee strength of flexors and extensors was measured at T3, T4 and T5. Lower limb loading asymmetry was measured during a sit-to-stand-to-sit movement at T1, T2, T3, T4 and T5, and a countermovement-jump at T4 and T5. An MRI was performed at T5 to assess morphology of thigh muscles and regeneration of the harvested tendons. NMES+ showed higher muscle strength for the hamstrings (T4, T5) and the quadriceps (T3, T4, T5), higher loading symmetry during stand-to-sit (T2, T3, T4, T5), sit-to-stand (T3, T4) and countermovement-jump (T5) than NAT. No differences were found between-groups for morphology of muscles and tendons, nor in regeneration of harvested tendons. NMES+ early after ACLr with hamstring graft improves muscle strength and knee function in the short- and long-term after surgery, regardless of tendon regeneration.

Association of Quadriceps Strength Symmetry and Surgical Status With Clinical Osteoarthritis Five Years After Anterior Cruciate Ligament Rupture

OBJECTIVE

The objective of this study was to examine the association of quadriceps strength symmetry and surgical status (anterior cruciate ligament [ACL] reconstruction or nonoperative management) with early clinical knee osteoarthritis (OA) 5 years after ACL injury or reconstruction.

METHODS

In total, 204 of 300 athletes were analyzed 5 years after ACL injury or reconstruction. Quadriceps strength was measured and reported as a limb symmetry index. We identified participants with early clinical knee OA using the criteria that 2 of 4 Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales score ≤85%. We calculated odds ratios (ORs) and 95% confidence intervals (95% CIs) using logistic regression and adjusted for age, sex, meniscal injury, and body mass index to examine the associations of quadriceps strength and surgical status with clinical knee OA.

RESULTS

In all, 21% of participants met the KOOS criteria for clinical knee OA. For every 1% increase in quadriceps limb symmetry index, there was a 4% lower odds of clinical OA (adjusted OR [OR_adj ] 0.96 [95% CI 0.93-0.99]) at 5 years. Surgical status was not associated with clinical knee OA (OR_adj 0.58 [95% CI 0.23-1.50]).

CONCLUSION

More symmetric quadriceps strength, but not surgical status, 5 years after ACL injury or reconstruction was associated with lower odds of clinical knee OA.

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.

Should return to pivoting sport be avoided for the secondary prevention of osteoarthritis after anterior cruciate ligament reconstruction? A prospective cohort study with MRI, radiographic and symptomatic outcomes

OBJECTIVE

To evaluate if returning to pivoting sport following anterior cruciate ligament reconstruction (ACLR) is associated with longitudinal structural and symptomatic osteoarthritis outcomes.

DESIGN

Eighty-one adults aged 18-50 years were followed prospectively 1- to 5-years post-ACLR. Return to pivoting sport was assessed at 1-, 3- and 5-years. Longitudinal changes in osteoarthritis features were evaluated from 1- and 5-year magnetic resonance imaging (MRI)s using MRI Osteoarthritis Knee Score (MOAKS). Radiographic osteoarthritis and self-reported knee symptoms, function and quality of life were assessed using the Osteoarthritis Research Society International (OARSI) atlas and Knee injury Osteoarthritis Outcome Score (KOOS), respectively, at 5 years post-ACLR. Generalised linear models (adjusted for baseline characteristics) assessed whether returning to pivoting sport was associated with risk of worsening osteoarthritis features on MRI, radiographic osteoarthritis and KOOS.

RESULTS

Thirty participants returned to pivoting sport 1-year post-ACLR and 50 returned at any time (i.e., 1-, 3- or 5-years). Returning to pivoting sport was not associated with worsening of any MRI osteoarthritis feature (risk ratio (RR) range: 0.59-2.91) or 5-year KOOS (β range: -2.73-3.69). Returning to pivoting sport at 1-year and up to 5-years post-ACLR was associated with a 50% (RR 0.49, 95%CI 0.10-2.37) and 40% (RR 0.60, 95%CI 0.16-2.17) reduced risk of radiographic osteoarthritis, respectively, but these risk reductions were inconclusive due to wide confidence intervals.

CONCLUSION

After ACLR, returning to pivoting sport was not associated with increased risk of worsening knee osteoarthritis features on MRI, radiographic osteoarthritis or knee symptoms. Participation in pivoting sport need not be avoided as part of osteoarthritis secondary prevention strategies.

The Role of Fatigue in Return to Sport Testing Following Anterior Cruciate Ligament Reconstruction

BACKGROUND

Fatigue may play a role in anterior cruciate ligament (ACL) injury, but has not been incorporated into objective test batteries for return to sport decisions following ACL reconstruction (ACLR) surgery. The effect of fatigue on muscle function and performance following surgery and rehabilitation has been poorly studied.

PURPOSE/HYPOTHESIS

The purpose of this study was to assess the effect of fatigue on performance of various hop tests used in clinical rehabilitation settings by examining LSI scores. The authors hypothesized that participants will have worse limb symmetry index scores following the fatigue protocol and that the operative limb (ACLR) will have a greater decline in function than the non-operative limb (CON).

STUDY DESIGN

Cross-Sectional Study.

METHODS

Participants (n=21 [Male = 15, Female = 6]; AGE = 24.6 ± 9.3) were at least six months post ACLR and in rehabilitation. Testing was performed over two separate sessions in either a non-fatigued (NFS) or fatigued state (FS). In the FS, individuals performed a series of exercises to exhaust muscular endurance, strength, and power systems, after which they performed as battery of seven hop tests (single hop for distance, triple hop for distance, crossover hop for distance, 6-meter timed hop, lateral rotation hop for distance, medial rotation hop for distance, and vertical jump for height). A 2(limb) x 2(time) ANOVA was used to compare limbs between each state.

RESULTS

Differences between limbs (CON vs ACLR) were observed for all hop tests in the NFS whereby the ACLR limb was observed to have reduced performance (↓5.4-9.1%, p <0.05). When tested in the FS, significant differences in performance between limbs remained for only the crossover (↓4.9%), medial rotation (↓7.1%), lateral rotation (↓5.5%), and vertical hop (↓10.0%)(p<0.05). When comparing the NFS and FS states, only the CON limb was observed to have significant decreases in performance of the Triple Hop (↓7.4%), Crossover (↓8.7%), and Lateral Rotation (↓5.2%)(p<0.05).

CONCLUSIONS

Following ACL reconstruction, there appears to be a greater loss in jump performance in the CON limb in the FS. These findings suggest it may be crucial to consider and assess the endurance of both limbs rather than just the ACLR limb when determining readiness for return to play.

LEVEL OF EVIDENCE

Level 3.

Does sex affect second ACL injury risk? A systematic review with meta-analysis

OBJECTIVE

To determine sex-based differences in risk of a second ACL injury (overall and by laterality) following primary ACL reconstruction in athletes who are attempting to return to sport.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

Systematic search of five databases conducted in August 2019.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies reporting sex-based differences in the incidence of second ACL injury in athletes attempting to return-to-sports and who were followed for at least 1 year following primary ACL reconstruction.

RESULTS

Nineteen studies were included in this review, with seven studies excluded from the primary meta-analysis due to high risk of bias. The remaining 12 studies (n=1431 females, n=1513 males) underwent meta-analysis, with all 19 studies included in a sensitivity analysis. Total second ACL injury risk was 21.9% (females: 22.8%, males: 20.3%). Females were found to have 10.7% risk of an ipsilateral ACL injury and 11.8% risk of a contralateral ACL injury. Males were found to have 12.0% risk of an ipsilateral ACL injury and 8.7% risk of a contralateral ACL injury. No statistically significant differences were observed for total second ACL injury risk (risk difference=-0.6%, 95% CI -4.9 to 3.7, p=0.783, I²=41%) or contralateral ACL injury risk (risk difference=1.9%, 95% CI -0.5% to 4.4%, p=0.113, I²=15%) between sexes. Females were found to have a 3.4% absolute risk reduction in subsequent ipsilateral ACL injury risk compared with males (risk difference=-3.4%, 95% CI -6.7% to -0.02%, p=0.037, I²=35%).

CONCLUSION

Both sexes have >20% increased risk of experiencing a second ACL injury. Any difference in the absolute risk of either a subsequent ipsilateral or contralateral ACL injury between sexes appears to be small.

REGISTRATION

PROSPERO (CRD42020148369).

Osteoarthritis year in review 2020: imaging

This narrative "Year in Review" highlights a selection of articles published between January 2019 and April 2020, to be presented at the OARSI World Congress 2020 within the field of osteoarthritis (OA) imaging. Articles were obtained from a PubMed search covering the above period, utilizing a variety of relevant search terms. We then selected original and review studies on OA-related imaging in humans, particularly those with direct clinical relevance, with a focus on the knee. Topics selected encompassed clinically relevant models of early OA, particularly imaging applications on cruciate ligament rupture, as these are of direct clinical interest and provide potential opportunity to evaluate preventive therapy. Further, imaging applications on structural modification of articular tissues in patients with established OA, by non-pharmacological, pharmacological and surgical interventions are summarized. Finally, novel deep learning approaches to imaging are reviewed, as these facilitate implementation and scaling of quantitative imaging application in clinical trials and clinical practice. Methodological or observational studies outside these key focus areas were not included. Studies focused on biology, biomechanics, biomarkers, genetics and epigenetics, and clinical studies that did not contain an imaging component are covered in other articles within the OARSI "Year in Review" series. In conclusion, exciting progress has been made in clinically validating human models of early OA, and the field of automated articular tissue segmentation. Most importantly though, it has been shown that structure modification of articular cartilage is possible, and future research should focus on the translation of these structural findings to clinical benefit.

Exercise-therapy and education for individuals one year after anterior cruciate ligament reconstruction: a pilot randomised controlled trial

BACKGROUND

Guided rehabilitation beyond 6-months is rare following anterior cruciate ligament reconstruction (ACLR), despite high prevalence of unacceptable symptoms and quality of life (QoL). Our primary aim was to determine the feasibility of a randomised controlled trial (RCT) evaluating a physiotherapist-guided intervention for individuals 1-year post-ACLR with persistent symptoms. Our secondary aim was to determine if a worthwhile treatment effect could be observed for the lower-limb focussed intervention (compared to the trunk-focussed intervention), for improvement in knee-related QoL, symptoms, and function.

DESIGN

Participant- and assessor-blinded, pilot feasibility RCT.

METHODS

Participant eligibility criteria: i) 12-15 months post-ACLR; ii) < 87.5/100 on the Knee injury and Osteoarthritis Outcome Score (KOOS) QoL subscale; and either a one-leg rise test < 22 repetitions, single-hop < 90% limb symmetry; or Anterior Knee Pain Scale < 87/100. Participants were randomised to lower-limb or trunk-focussed focussed exercise and education. Both interventions involved 8 face-to-face physiotherapy sessions over 16-weeks. Feasibility was assessed by eligibility rate (> 1 in 3 screened), recruitment rate (> 4 participants/month), retention (< 20% drop-out), physiotherapy attendance and unsupervised exercise adherence (> 80%). Between-group differences for knee-related QoL (KOOS-QoL, ACL-QoL), symptoms (KOOS-Pain, KOOS-Symptoms), and function (KOOS-Sport, functional performance tests) were used to verify that the worthwhile effect (greater than the minimal detectable change for each measure) was contained within the 95% confidence interval.

RESULTS

47% of those screened were eligible, and 27 participants (3 participants/month; 48% men, 34±12 years) were randomised. Two did not commence treatment, and two were lost to follow-up (16% drop-out). Physiotherapy attendance was > 80% for both groups but reported adherence to unsupervised exercise was low (< 55%). Both interventions had potentially worthwhile effects for KOOS-QoL and ACL-QoL, while the lower-limb focussed intervention had potentially greater effects for KOOS-Sport, KOOS-Pain, and functional performance.

CONCLUSIONS

A larger-scale RCT is warranted. All feasibility criteria were met, or reasonable recommendations could be made to achieve the criteria in future trials. Strategies to increase recruitment rate and exercise adherence are required. The potential worthwhile effects for knee-related QoL, symptoms, and function indicates a fully-powered RCT may detect a clinically meaningful effect.

TRIAL REGISTRATION

Prospectively registered ( ACTRN12616000564459 ).