Simple decision rules can reduce reinjury risk by 84% after ACL reconstruction: the Delaware-Oslo ACL cohort study

Strength symmetry after autograft anterior cruciate ligament reconstruction

OBJECTIVE

To compare postoperative isometric quadriceps strength indices (QI%) and hamstring strength limb symmetry indices (HI%) between partial thickness quadriceps tendon (pQT), full thickness quadriceps tendon (fQT), and bone-patellar-tendon bone (BPTB) autograft anterior cruciate ligament reconstruction (ACLR).

METHODS

Patients with primary ACLR with pQT, fQT, or BPTB autograft with the documentation of quantitative postoperative strength assessments between 2016 and 2021 were included. Isometric Biodex data, including QI% and HI% (calculated as the percentage of involved to uninvolved limb strength) were collected between 5 and 8 months and between 9 and 15 months postoperatively.

RESULTS

In total, 124 and 51 patients had 5-8- and 9-15-month follow-up strength data, respectively. No significant difference was detected between groups for sex. However, patients undergoing fQT were found to be older than those undergoing BPTB (24.6±7 vs 20.2±5; ​p = 0.01). There were no significant differences in the number of concomitant meniscus repairs between the groups (pQT vs. fQT vs. BPTB). No significant differences were detected in median (min-max) QI% between pQT, fQT, and BPTB 5-8 months [87 ​% (44%-130 ​%), 84 ​% (44%-110 ​%), 82 ​% (37%-110 ​%) or 9-15 months [89 ​% (50%-110 ​%), 89 ​% (67%-110 ​%), and 90 ​% (74%-140 ​%)] postoperatively. Similarly, no differences were detected in median HI% between the groups 5-8 months or 9-15 months postoperatively.

CONCLUSION

The study was unable to detect differences in the recovery of quadriceps strength between patients undergoing ACLR with pQT, fQT, and BPTB autografts at 5-8 months and 9-15-months postoperatively.

LEVEL OF EVIDENCE

III.

The End of the Formal Rehabilitation Is Not the End of Rehabilitation: Knee Function Deficits Remain After Anterior Cruciate Ligament Reconstruction

OBJECTIVE

To rate athletes' functional ability and return to sport (RTS) success at the end of their individual, formal, medically prescribed rehabilitation after anterior anterior cruciate ligament (ACL) reconstruction.

METHODS

In our prospective multicenter cohort study, 88 (42 females) adults aged 18-35 years after acute unilateral ACL rupture and subsequent hamstring grafting were included. All patients were prospectively monitored during their rehabilitation and RTS process until the end of their formal rehabilitation and RTS release. As outcome measures, functional hop and jump tests (front hop, balance hops, and drop jump screening test) and self-report outcomes (Knee Injury and Osteoarthritis Outcome Score, ACL-RTS after injury) were assessed. Literature-based cut-off values were selected to rate each performance as fulfilled or not.

RESULTS

At 7.5 months (SD 2.3 months) after surgery, the percentage of participants meeting the functional thresholds ranged from 4% (Knee Injury and Osteoarthritis Outcome Score SPORT) and over 44% (ACL-RTS after injury sum score) to 59% (Knee Injury and Osteoarthritis Outcome Score activities of all daily living) in the self-report and from 29% (Balance side hop) to 69% (normalized knee separation distance) in performance testing. Only 4% fulfilled all the cut-offs, while 45% returned to the same type and level of sport. Participants who successfully returned to their previous sport (type and level) were more likely to be "over-cut-off-performers."

CONCLUSIONS

The low share of the athletes who fulfilled the functional RTS criteria highlights the importance of continuing the rehabilitation measures after the formal completion to assess the need for and success of, inter alia, secondary-preventive therapies.

Large variation in postoperative rehabilitation protocols following operative treatment of osteochondral lesions of the talus: A systematic review and meta-analysis on >200 studies

PURPOSE

A treatment-specific rehabilitation protocol and well-defined return-to-play criteria guide clinical decision-making on return to normal function, activity, sports and performance after surgical treatment for osteochondral lesion of the talus (OLT). The optimal rehabilitation protocols in the current literature remain unclear. The purpose of this study was to explore the existing literature on rehabilitation protocols from the early postoperative phase to return to sport onwards after different types of surgical treatment of OLTs.

METHODS

PubMed, Embase, CDSR, DARE and Central were searched systematically from inception to February 2023 according to the PRISMA 2020 guidelines. All clinical studies with a description of postoperative rehabilitation criteria after surgical treatment of OLTs were included. The primary outcome of this study is the extent of reportage for each rehabilitation parameter expressed in percentage. The secondary outcome is the reported median time for each parameter in rehabilitation protocols for all different treatment modalities (type of surgery). The median time, expressed as number of weeks, for each parameter was compared between different types of surgery.

RESULTS

A total of 227 articles were included reporting on 255 different rehabilitation protocols from seven different types of surgery. Weight-bearing instructions were reported in 84%-100% and the use of a cast or walker was prescribed in 27%-100%. Range of motion exercises were described in 54%-100% whereas physical therapy was advised in 21%-67% of the protocols. Any advice on return to sport was described in 0%-67% protocols. A nonparametric analysis of variance showed significant differences between the different surgical treatment modalities for the following parameters between the treatment groups: time to full weight-bearing (p < 0.0003) and return to high impact level of sports (p < 0.0003). Subjective or objective criteria for progression during rehabilitation were reported in only 24% of the studies.

CONCLUSION

An in-depth exploration of the current literature showed substantial variation in postoperative rehabilitation guidelines with an associated underreporting of the most important rehabilitation parameters in postoperative protocols after surgical treatment of OLTs. Furthermore, nearly all rehabilitation protocols were constructed according to a time-based approach. Only one out of four reported either objective or subjective criteria.

LEVEL OF EVIDENCE

Level IV, systematic review.

Comparison of immediate versus optional delayed surgical repair for treatment of acute anterior cruciate ligament injury through a parallel, multicentric, pragmatic randomized controlled trial - IODA trial

BACKGROUND

Standard care for anterior cruciate ligament (ACL) injuries often includes surgical reconstruction of the ACL. However, two randomized controlled trials [1, 2] (RCT) concluded that conservative treatment does not result in inferior clinical outcomes compared to immediate ACL reconstruction. More research is needed to verify these results and assess whether patient-specific parameters determine if a patient would benefit from one treatment option over the other.

METHODS

This is a pragmatic, multi-center RCT with two parallel groups. Patients with an acute ACL injury will be recruited from Belgian hospitals. Patients will be randomized to conservative treatment (rehabilitation + optional delayed surgery) or immediate ACL reconstruction (< 12 weeks). The primary outcome is the Knee injury and Osteoarthritis Outcome Score (KOOS) at 7 months (short term) and 1-year long term) post-injury. These following additional outcomes will be administered at 4 and 7 months (short term) and 1, 2, and 3 years post-injury (long term): patient-reported outcomes concerning knee symptoms, knee function and quality of life, functional knee tests, time to return to pre-injury activity level and return to work, structural knee joint damage and cartilage health (only at 4 months and 3 years post-injury), as well as adverse events such as re-rupture rates. Furthermore, the secondary objective is to identify (through a predictive analysis) individuals who would benefit the most from early reconstruction versus those who should rather be treated conservatively.

DISCUSSION

This large RCT will assess the clinical effectiveness of both surgical and conservative treatment. In addition, it will be the first study that provides insights into which patient-specific factors predict successful outcomes after conservative treatment of ACL injuries. These results will be the first step toward early patient identification regarding treatment decisions. This is urgently needed to avoid (1) delayed surgeries and prolonged rehabilitation and (2) unnecessary surgeries.

TRIAL REGISTRATION

this trial was registered on ClinicalTrials.gov (NCT05747079) on 10/02/2023.

Restoring Knee Flexor Strength Symmetry Requires 2 Years After ACL Reconstruction, But Does It Matter for Second ACL Injuries? A Systematic Review and Meta-analysis

BACKGROUND

It is unknown whether knee flexor strength recovers after anterior cruciate ligament (ACL) reconstruction with a hamstring tendon (HT) autograft and whether persistent knee flexor strength asymmetry is associated to a second ACL injury.

OBJECTIVE

We aimed to systematically review (1) whether knee flexor strength recovers after ACL reconstruction with HT autografts, and (2) whether it influences the association with a second ACL injury. A third aim was to summarize the methodology used to assess knee flexor strength.

DESIGN

Systematic review and meta-analysis reported according to PRISMA.

METHODS

A systematic search was performed using the Cochrane Library, Embase, Medline, PEDRo, and AMED databases from inception to December 2021 and until completion in January 2023. Human clinical trials written in English and conducted as randomized controlled trials, longitudinal cohort, cross-sectional, and case-control studies on patients with index ACL reconstructions with HT autografts harvested from the ipsilateral side were considered. Knee flexor strength was measured isokinetically in both the reconstructed and uninjured limb to enable the calculation of the limb symmetry index (LSI). The Risk of Bias Assessment Tool for Non-Randomized Studies was used to assess risk of bias for non-randomized studies and the revised Cochrane Risk of Bias tool was used for randomized controlled trials. For the meta-analysis, the LSI (mean ± standard error) for concentric knee flexor strength at angular velocities of 60°/second (s) and 180°/s preoperatively and at 3 months, 6 months, 12 months, and 24 months were pooled as weighted means with standard errors.

RESULTS

The search yielded 64 studies with a total of 8378 patients, which were included for the assessment of recovery of knee flexor strength LSI, and a total of 610 patients from four studies that investigated the association between knee flexor strength and second ACL injuries. At 1 year after ACL reconstruction, the knee flexor strength LSI had recovered to 89.0% (95% CI 87.3; 90.7%) and 88.3% (95% CI 85.5; 91.1%) for the velocities of 60°/s and 180°/s, respectively. At 2 years, the LSI was 91.7% (95% CI 90.8; 92.6%) and 91.2% (95% CI 88.1; 94.2%), for velocities of 60°/s and 180°/s, respectively. For the association between knee flexor strength and second ACL injuries, there was insufficient and contradictory data.

CONCLUSIONS

There was low to very low certainty of evidence indicating that the recovery of knee flexor strength LSI, defined as ≥ 90% of the uninjured side, takes up to 2 years after ACL reconstruction with HT autografts. Whether knee flexor strength deficits influence the association of second ACL injuries is still uncertain. There was considerable heterogeneity in the methodology used for knee flexor strength assessment, which together with the low to very low certainty of evidence, warrants further caution in the interpretation of our results.

REGISTRATION NUMBER

CRD42022286773.

Upper Limb Strength and Performance Deficits after Glenohumeral Joint Stabilization Surgery in Contact and Collision Athletes

PURPOSE

The primary aim was to identify and quantify differences in interlimb asymmetry magnitudes across a battery of upper extremity strength and performance tests at 4 and 6 months after glenohumeral joint stabilization surgery shoulder stabilization in contact and collision athletes compared with an un-injured group. A secondary aim was to investigate if identified asymmetry magnitudes changed from 4 to 6 months after glenohumeral joint stabilization surgery. The third aim was to explore associations within the different performance and strength variables.

METHODS

Fifty-six male contact and collision sport athletes who had had undergone unilateral glenohumeral joint stabilization were tested at 4 and 6 months after surgery. An un-injured control group ( n = 39 for upper extremity performance tests, n = 47 for isokinetic dynamometry) were tested on a single occasion. Three upper extremity force platform-based performance tests and angle-specific concentric internal and external isokinetic shoulder rotational strength were assessed, and interlimb asymmetries were compared between the two groups.

RESULTS

At 4 months after surgery, the glenohumeral joint stabilization group demonstrated significantly higher absolute interlimb asymmetry values than the un-injured group for almost all the performance test variables. In the ballistic upper-body performance tests, the glenohumeral joint stabilization group achieved only half the body elevation reached by the un-injured (counter-movement push-up jump height ( η2 = 0.50) and press-jump jump height ( η2 = 0.39)). At 6 months after surgery, absolute interlimb asymmetries reduced for the performance test variables, but some asymmetry persisted. The glenohumeral joint stabilization group had significantly greater absolute interlimb asymmetries for five out the eight isokinetic variables.

CONCLUSIONS

Contact and collision athletes who may be cleared to return to sport at 4 to 6 months after glenohumeral joint stabilization surgery shoulder stabilization continue to demonstrate upper limb strength and performance deficits when compared with their un-injured limb and their un-injured counterparts.

Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) subcategories are affected by subjective running ability and medial single-leg hop distance in postreconstruction patients at 6 months

Purpose

This study aimed to investigate the intricate relationship between physical function factors and each subcategory score of the Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scale among patients following ACL reconstruction.

Methods

Participants comprised 59 patients who had undergone primary ACL reconstruction using hamstring tendon. The ACL-RSI was completed 6 months after reconstruction and five physical functions were measured in patients on the same day. Simple linear regression was performed multiple times to investigate the relationship between ACL-RSI subcategory scores as a dependent variable and each independent variable (knee strength, leg anterior reach distance, single-leg hop [SLH] distances, side bridge endurance, and subjective running ability). Multiple regression analysis was performed using a stepwise method, with factors showing a risk rate <0.05 in simple linear regression analyses as independent variables and the ACL-RSI in each subcategory score as the dependent variable.

Results

Multiple regression analysis showed that subjective running ability affected all subcategories (p ≤ 0.001), and that the limb symmetry index of medial SLH distance affected both the Emotions (p = 0.047) and Confidence (p = 0.009) subcategories. Higher subjective running ability and greater limb symmetry in the medial SLH were thus positively associated with each dimension of psychological readiness.

Conclusions

This study highlights the differential impact of physical function factors on specific subcategories of the ACL-RSI scale, providing clinicians with insights for designing targeted rehabilitation strategies. This original paper suggests the importance of analysing factors related to subcategory scores in addition to total ACL-RSI score, and could contribute to the understanding of determinants for a successful return to sport following ACL reconstruction.

Level of Evidence

Level IV.

Only 10% of Patients With a Concomitant MCL Injury Return to Their Preinjury Level of Sport 1 Year After ACL Reconstruction: A Matched Comparison With Isolated ACL Reconstruction

BACKGROUND

There is a need for an increased understanding of the way a concomitant medial collateral ligament (MCL) injury may influence outcome after anterior cruciate ligament (ACL) reconstruction.

HYPOTHESIS

Patients with a concomitant MCL injury would have inferior clinical outcomes compared with a matched cohort of patients undergoing ACL reconstruction without an MCL injury.

STUDY DESIGN

Matched registry-based cohort study; case-control.

LEVEL OF EVIDENCE

Level 3.

METHODS

Data from the Swedish National Knee Ligament Registry and a local rehabilitation outcome registry were utilized. Patients who had undergone a primary ACL reconstruction with a concomitant nonsurgically treated MCL injury (ACL + MCL group) were matched with patients who had undergone an ACL reconstruction without an MCL injury (ACL group), in a 1:3 ratio. The primary outcome was return to knee-strenuous sport, defined as a Tegner activity scale ≥6, at the 1-year follow-up. In addition, return to preinjury level of sport, muscle function tests, and patient-reported outcomes (PROs) were compared between the groups.

RESULTS

The ACL + MCL group comprised 30 patients, matched with 90 patients in the ACL group. At the 1-year follow-up, 14 patients (46.7%) in the ACL + MCL group had return to sport (RTS) compared with 44 patients (48.9%) in the ACL group (P = 0.37). A significantly lower proportion of patients in the ACL + MCL group had returned to their preinjury level of sport compared with the ACL group (10.0% compared with 25.6%, adjusted P = 0.01). No differences were found between the groups across a battery of strength and hop tests or in any of the assessed PROs. The ACL + MCL group reported a mean 1-year ACL-RSI after injury of 59.4 (SD 21.6), whereas the ACL group reported 57.9 (SD 19.4), P = 0.60.

CONCLUSION

Patients with a concomitant nonsurgically treated MCL injury did not return to their preinjury level of sport to the same extent as patients without an MCL injury 1 year after ACL reconstruction. However, there was no difference between the groups in terms of return to knee strenuous activity, muscle function, or PROs.

CLINICAL RELEVANCE

Patients with a concomitant nonsurgically treated MCL injury may reach outcomes similar to those of patients without an MCL injury 1 year after an ACL reconstruction. However, few patients return to their preinjury level of sport at 1 year.

Anterior Cruciate Ligament Reconstruction Return-to-Sport Decision-Making: A Scoping Review

CONTEXT

Clinical guidelines support the use of testing batteries to assess athlete readiness for return to sport (RTS) and risk of reinjury after anterior cruciate ligament (ACL) reconstruction (ACL-R). There is no consensus on the composition of the testing batteries. Test selection is based mainly on commonality in research, personal preference, and equipment availability. Including athletic performance assessments (APA) used in the athlete's sport may assist RTS decision-making for stakeholders.

OBJECTIVE

To determine whether APA for speed, agility, strength, or cardiovascular endurance are (1) used in ACL-R RTS literature and (2) indicative of RTS or reinjury rates.

DATA SOURCES

A systematic search was performed in MEDLINE, EMBASE, CINAHL, SPORTDiscus, Scopus, Web of Science, and ProQuest Dissertations and Theses Global.

STUDY SELECTION

Eligibility criteria were as follows: (1) athletes between 6 months and 2 years post-ACL-R, (2) commonly used APA, (3) peer-reviewed primary study with original published data.

STUDY DESIGN

Scoping Review.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

A total of 17 studies included 24 instances of APA with a high degree of heterogeneity for both tests and protocols.

RESULTS

Agility makes up 75% of the APA. Only 17.6% of studies reported RTS or reinjury rates, none of which reported a significant relationship between these rates and APA outcomes.

CONCLUSION

Speed, strength, and cardiovascular endurance tests are underrepresented in ACL-R RTS literature. Compared with healthy controls, deficits in APA results for ACL-R athletes were common; however, many studies reported significant improvements in results for ACL-R athletes over time. There is some evidence that well-trained ACL-R athletes can match the performance of uninjured athletes in high-level sports.

Weaker Quadriceps Muscle Strength With a Quadriceps Tendon Graft Compared With a Patellar or Hamstring Tendon Graft at 7 Months After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Impaired quadriceps muscle strength after anterior cruciate ligament reconstruction (ACLR) is associated with worse clinical outcomes and a risk of reinjuries. Yet, we know little about quadriceps muscle strength in patients reconstructed with a quadriceps tendon (QT) graft, which is increasing in popularity worldwide.

PURPOSE

To describe and compare isokinetic quadriceps strength in patients undergoing ACLR with a QT, hamstring tendon (HT), or bone-patellar tendon-bone (BPTB) autograft.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

We included patients with QT grafts (n = 104) and matched them to patients with HT (n = 104) and BPTB (n = 104) grafts based on age, sex, and associated meniscal surgery. Data were collected through clinical strength testing at a mean of 7 ± 1 months postoperatively. Isokinetic strength was measured at 90 deg/s, and quadriceps strength was expressed as the limb symmetry index (LSI) for peak torque, total work, torque at 30° of knee flexion, and time to peak torque.

RESULTS

Patients with QT grafts had the most impaired isokinetic quadriceps strength, with the LSI ranging between 67.5% and 75.1%, followed by those with BPTB grafts (74.4%-81.5%) and HT grafts (84.0%-89.0%). Patients with QT grafts had a significantly lower LSI for all variables compared with patients with HT grafts (mean difference: peak torque: -17.4% [95% CI, -21.7 to -13.2], P < .001; total work: -15.9% [95% CI, -20.6 to -11.1], P < .001; torque at 30° of knee flexion: -8.8% [95% CI, -14.7 to -2.9], P = .001; time to peak torque: -17.7% [95% CI, -25.8 to -9.6], P < .001). Compared with patients with BPTB grafts, patients with QT grafts had a significantly lower LSI for all variables (mean difference: peak torque: -6.9% [95% CI, -11.2 to -2.7], P < .001; total work: -7.7% [95% CI, -12.4 to -2.9], P < .001; torque at 30° of knee flexion: -6.3% [95% CI, -12.2 to -0.5], P = .03; time to peak torque: -8.8% [95% CI, -16.9 to -0.7], P = .03). None of the graft groups reached a mean LSI of >90% for peak torque (QT: 67.5% [95% CI, 64.8-70.1]; HT: 84.9% [95% CI, 82.4-87.4]; BPTB: 74.4% [95% CI, 72.0-76.9]).

CONCLUSION

At 7 months after ACLR, patients with QT grafts had significantly worse isokinetic quadriceps strength than patients with HT and BPTB grafts. None of the 3 graft groups reached a mean LSI of >90% in quadriceps strength.

Inline dynamometry provides reliable measurements of quadriceps strength in healthy and ACL-reconstructed individuals and is a valid substitute for isometric electromechanical dynamometry following ACL reconstruction

BACKGROUND

Quadriceps strength testing is recommended to guide rehabilitation and mitigate the risk of second injury following anterior cruciate ligament (ACL) reconstruction. Hand-held dynamometry is a practical alternative to electromechanical dynamometry but demonstrates insufficient reliability and criterion validity in healthy and ACL-reconstructed participants respectively. The purpose of this study is to investigate the reliability and concurrent validity of inline dynamometry for measuring quadriceps strength. The hypotheses are that intra-class correlation coefficient (ICC) values will be >0.90 for reliability and concurrent validity.

METHODS

This was a cross sectional study using a within-participant, repeated measures design. Isometric quadriceps testing was performed at 60° knee flexion in 50 healthy and 52 ACL-reconstructed participants. Interrater reliability, intrarater reliability, and concurrent validity of inline dynamometry was investigated through calculation of ICCs, Bland-Altman analysis, linear regression, standard error of measurement (SEM) and minimal detectable change (MDC).

RESULTS

The lower bounds of the 95% confidence intervals were >0.90 for all reliability and validity ICCs in healthy and ACL-reconstructed participants, except for intrarater reliability in healthy participants using absolute scores (ICC = 0.936 [95% CI 0.890-0.963]). In ACL-reconstructed participants, Bland-Altman bias was 0.01 Nm/kg for absolute and average scores, limits of agreement were -11.74% to 12.59% for absolute scores, the SEM was 0.13Nm/kg (95% CI 0.10-0.17) and the MDC was 0.36Nm/kg (95% CI 0.28 - 0.47).

CONCLUSION

Inline dynamometry is a reliable and economical alternative to electromechanical dynamometry for the assessment of quadriceps strength following ACL-reconstruction.

CLINICAL TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT05109871).

Female Athletes With Better Psychological Readiness Are at Higher Risk for Second ACL Injury After Primary ACL Reconstruction

BACKGROUND

Approximately 1 in 4 athletes returning to sports will sustain a second anterior cruciate ligament (ACL) injury. Psychological factors related to kinesiophobia, confidence, and psychological readiness are associated with second ACL injury; however, the evidence is conflicting.

HYPOTHESIS

Athletes who sustain a second ACL injury (ie, graft rupture or contralateral ACL rupture) within 2 years of ACL reconstruction (ACLR) would have greater kinesiophobia, less confidence, and lower psychological readiness prior to return to sport (RTS) compared with athletes who do not sustain a second ACL injury.

STUDY DESIGN

Secondary analysis of a prospective randomized trial.

LEVEL OF EVIDENCE

Level 3.

METHODS

A total of 39 female Level I/II athletes completed the following measures after postoperative rehabilitation and a 10-session RTS and second ACL injury prevention program: ACL Return to Sport after Injury (ACL-RSI) scale, the 11-item Tampa Scale of Kinesiophobia (TSK-11), and question 3 on the Knee injury and Osteoarthritis Outcome Score (KOOS) quality of life (QoL) subscale. Athletes were dichotomized based on whether they sustained a second ACL injury within 2 years of ACLR or not. Independent t tests determined group differences in TSK-11, KOOS-QoL, ACL-RSI, and the 3 individual components of the ACL-RSI (ie, emotions, confidence, risk appraisal).

RESULTS

Nine athletes sustained a second ACL injury (4 graft ruptures and 5 contralateral ACL ruptures). The group that sustained a second ACL injury had higher scores on the ACL-RSI (P = 0.03), higher on the risk appraisal questions of the ACL-RSI (P < 0.01), and met RTS criteria sooner than athletes who did not (P = 0.04). All second ACL injuries occurred in athletes who underwent primary ACLR with hamstring tendon autografts.

CONCLUSION

Athletes who sustained a second ACL within 2 years of ACLR had a more positive psychological outlook, higher scores on the specific questions related to the risk appraisal construct of the ACL-RSI, and met RTS criteria sooner than athletes who did not sustain a second ACL injury.

CLINICAL RELEVANCE

Counseling athletes about delaying RTS to reduce the risk of second ACL injury may be especially important in athletes who display high psychological readiness and meet RTS criteria sooner.

Clinical practice and barriers among Swiss physiotherapists treating patients with anterior cruciate ligament reconstruction: A survey of pre-operative rehabilitation to return to sport

OBJECTIVES

To investigate current clinical practice of Swiss physiotherapists treating patients with anterior cruciate ligament reconstruction (ACLR) from pre-operative rehabilitation until return to sport (RTS). We assessed optimisation strategies in daily practice and the perceived barriers to these optimisations, and evaluated whether there was a relevant difference in clinical practice for physiotherapists with post-graduate certification in sports physiotherapy or deep clinical experience and those without such experience.

DESIGN

Cross-sectional survey.

SETTING

Online survey platform.

PARTICIPANTS

Swiss physiotherapists.

MAIN OUTCOME MEASURES

The survey comprised six sections: participant information, pre-operative rehabilitation, post-operative rehabilitation, RTS, re-injury prevention, and optimisation strategies and barriers.

RESULTS

A minority of physiotherapists treated ACLR patients pre-operatively. Overall, 91% included quadriceps open kinetic chain exercise in their treatment, 37% used patient-reported outcomes measures (PROMs) and 39% considered psychological criteria when making decisions about RTS. Most physiotherapists (67%) felt limited due to the time available, the number of prescriptions and the tariffication system.

CONCLUSION

This study highlights areas within ACLR rehabilitation practice in Switzerland that could be improve. Improvements in understanding of the barriers to implementation of best evidence in practice and a redefinition of the clinical process around ACLR rehabilitation in Switzerland are necessary.

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).

Asymmetric loading strategies during squats following anterior cruciate ligament reconstruction: A longitudinal investigation with curve analyses throughout and after rehabilitation

Investigations of kinetic asymmetries during bilateral squats following anterior cruciate ligament reconstruction (ACLR) are limited to mainly cross-sectional studies and discrete value data extracted at specific knee angles. We assessed loading asymmetries during squats longitudinally throughout rehabilitation using curve analysis and compared patient-reported outcome measures (PROMs) between those with and without asymmetry. Bodyweight squats were performed by 24 individuals (13 females) post-ACLR on three occasions: (1) Early 2.9 (1.1) months; (2) Mid 8.8 (3.1) months; (3) at Return to Sport (RTS) 13.1 (3.6) months; and 29 asymptomatic controls (22 females) once. Time-normalized between-leg asymmetry curves of sagittal plane hip, knee, and ankle moments and vertical ground reaction forces were compared using functional data analysis methods. Individual asymmetrical loading for ACLR was classified when exceeding the 95% confidence interval of controls during ≥50% of the squat. At Early, ACLR had greater asymmetry than controls for knee (15%-100% eccentric phase; 0%-100% concentric) and ankle flexion moments (56%-65% concentric). At Mid, ACLR had greater asymmetry for knee (41%-72% eccentric) and ankle flexion moments (56%-69% concentric). No between-group differences were found at RTS. From Early to RTS, ACLR reduced asymmetry for hip (21%-46% eccentric), knee (27%-58% concentric), and ankle flexion moments (21%-57% eccentric). At Early, 11/24 underloaded their ACLR knee and 1 overloaded compared with controls. At RTS, 4 underloaded and 6 overloaded. No differences in PROMs were found based on loading asymmetry. Beyond the early phase of rehabilitation from ACLR, individual-level analyses are required to reveal differing loading strategies during bilateral squats.

Time to treat the tendon rupture induced by surgery: early hypertrophy of the patellar tendon graft site predicts strong quadriceps after ACLR with bone-patellar tendon-bone autograft

PURPOSE

Quadriceps dysfunction is ubiquitous after anterior cruciate ligament reconstruction, especially when using bone-patellar tendon-bone (BPTB) autografts. The role of patellar tendon hypertrophy after graft harvest on knee extensor strength is unknown. The purpose of this study was to determine the predictive ability of patellar tendon (PT) and quadriceps muscle (Quad) cross-sectional area (CSA) on knee extensor strength 1-2 months after ACLR using BPTB autografts.

METHODS

This is a cross-sectional analysis of a cohort 1-2 months after ACLR using BPTB autograft. Peak knee extensor torque, and PT and Quad CSA measured using ultrasound imaging, were collected in 13 males and 14 females. Simple linear regressions compared quadriceps strength index (QI) against limb symmetry index (LSI) in PT and Quad CSA. Multiple linear regressions with sequential model comparisons predicting peak knee extensor torque were performed for each limb. The base model included demographics. Quad CSA was added in the first model, then PT CSA was added in the second model.

RESULTS

Both PT (p < 0.001, R2 = 0.693) and Quadriceps CSA (p = 0.013, R2 = 0.223) LSI had a positive linear relationship with QI. In the involved limb, addition of PT CSA significantly improved the model (R2 = 0.781, ΔR2 = 0.211, p for ΔR2 < 0.001). In the uninvolved limb, the addition of Quad CSA improved the model, but the addition of PT CSA did not.

CONCLUSION

PT LSI was more predictive of QI than Quad CSA LSI. Involved limb PT CSA mattered more in predicting peak knee extensor torque than did Quad CSA, but in the uninvolved limb, Quad CSA was the most important predictor of peak knee extensor torque. Graft site patellar tendon hypertrophy is key for strong quadriceps early after ACLR. Early targeted loading via exercise to promote healing of the graft site patellar tendon may bring patients a step closer to winning their battle against quadriceps dysfunction.

LEVEL OF EVIDENCE

Level I.

Neurocognitive and Reactive Return to Play Testing Protocol in Overhead Athletes Following Upper Extremity Injury

The incidence of upper extremity (UE) injuries in sport, particularly with the shoulder and elbow in baseball/softball players, appears to be increasing yearly, especially in younger age athletes. Improving the objective criteria and testing methods used to determine return to play (RTP) readiness following non-operative or post-operative management of UE injuries is one aspect of the rehabilitation process that may significantly help in reducing reinjury rates. Currently, the majority of clinicians are still using post operative time frame and/or strength/range of motion as their main criteria for clearance to RTP following UE injury. This demonstrates an inadequate reflection of the actual unpredictable, dynamic environment athletes are returning to participate in. In our clinical experiences, objective testing to allow for clearance to sport participation should incorporate neurocognitive and reactive testing to promote improvements in the athlete's ability to dual task and focus/concentrate on the multi-dimensional tasks at hand. We know that neuroplastic changes occur following UE injury resulting in decreased proprioception and increased motor activation with simple UE tasks. Currently the research on UE return to play testing is limited. The purpose of this clinical commentary was to describe the utilization and provide reference values for a series of reactive neurocognitive UE tests, to assist with RTP, in high school and collegiate overhead athletes (baseball and softball) utilizing the Blaze Pod light system. The use of a more dynamic reactive testing battery may decrease the reinjury rates when an athlete is cleared for participation by measuring readiness in chaotic circumstances that are more reflective of the sporting environment the athlete is working to return to resulting in a greater sense of confidence, performance and prevention of reinjuries.

Sports activity level after ACL reconstruction is predicted by vastus medialis or vastus medialis obliquus thickness, single leg triple hop distance or 6-m timed hop, and quality of life score

PURPOSE

Recovery after anterior cruciate ligament reconstruction (ACLR) may take > 2 years, and younger athletes have higher re-injury risk. The purpose of this prospective longitudinal study was to determine how the early to mid-term Tegner Activity Level Scale (TALS) scores of athletically active males ≥ 2 years post-ACLR follow-up was predicted by bilateral isokinetic knee extensor and flexor torque, quadriceps femoris thickness, single leg hop test performance, and self-reported knee function (Knee Injury and Osteoarthritis Outcome Score (KOOS); International Knee Documentation Committee (IKDC) Subjective Assessment score).

METHODS

After ACLR with a hamstring tendon autograft and safely returning to sports at least twice weekly, 23 men (18.4 ± 3.5 years of age) were evaluated at final follow-up (mean = 4.5, range = 2-7 years). Exploratory forward stepwise multiple regression was used to determine the relationship between independent surgical and non-surgical lower limb variables peak concentric isokinetic knee extensor-flexor torque at 60°/sec and 180°/sec, quadriceps femoris muscle thickness, single leg hop test profile results, KOOS subscale scores, IKDC Subjective Assessment scores, and time post-ACLR on TALS scores at final follow-up.

RESULTS

Subject TALS scores were predicted by KOOS quality of life subscale score, surgical limb vastus medialis obliquus (VMO) thickness, and surgical limb single leg triple hop for distance (SLTHD) performance. Subject TALS scores were also predicted by KOOS quality of life subscale score, non-surgical limb vastus medialis (VM) thickness, and non-surgical limb 6 m single leg timed hop (6MSLTH) performance.

CONCLUSION

TALS scores were influenced differently by surgical and non-surgical lower extremity factors. At ≥ 2 years post-ACLR, ultrasound VM and VMO thickness measurements, single leg hop tests that challenge knee extensor function, and self-reported quality of life measurements predicted sports activity levels. The SLTHD test may be better than the 6MSLTH for predicting long-term surgical limb function.

Greater self-efficacy, psychological readiness and return to sport amongst paediatric patients compared with adolescents and young adults, 8 and 12 months after ACL reconstruction

PURPOSE

The purpose of this study was to evaluate differences in rehabilitation-specific outcomes between paediatric patients, adolescents and young adults within the first 2 years after anterior cruciate ligament (ACL) reconstruction. A further aim was to determine whether patient age was associated with an increased risk of not achieving symmetrical muscle function within the first 2 years after ACL reconstruction.

METHODS

The patient data in the present study were extracted from the rehabilitation outcome registry, Project ACL. Patients aged 11-25 years registered for primary ACL reconstruction with a hamstring tendon autograft between April 1, 2013 and November 23, 2020 were included. A total of 691 patients met the inclusion criteria and were included in the study; 41 paediatric patients (females 11-13, males 11-15 years), 347 adolescents (females 14-19, males 16-19 years) and 303 young adults (females 20-25, males 20-25 years).

RESULTS

The comparison between groups revealed that 70% of paediatric patients, 39% of adolescents and 35% of young adults had returned to knee-strenuous sport at 8 months and that 90% of paediatric patients, 71% of adolescents and 62% of young adults had returned to sport at 12 months. Paediatric patients also reported higher scores compared with both the other patient groups on the Knee Self-Efficacy Scale (K-SES) and the Anterior Cruciate Ligament Return to Sport after Injury scale (ACL-RSI) at 8 and 12 months.

CONCLUSIONS

A larger proportion of paediatric patients had returned to sport compared with adolescents and young adults 8 and 12 months after ACL reconstruction. Paediatric patients also reported higher self-efficacy and greater psychological readiness to return to sport at 8 and 12 months than the other two groups. No differences in terms of muscle function tests when comparing paediatric patients, adolescents and young adults were found.

LEVEL OF EVIDENCE

II.

Contralateral hamstring autografts do not provide benefit compared to ipsilateral hamstring autografts in primary or revision anterior cruciate ligament reconstruction: a systematic review

PURPOSE

To evaluate the clinical outcomes of primary or revision ACL reconstruction (ACLR) after contralateral hamstring autografts versus ipsilateral hamstring autograft harvest.

METHODS

Three databases (MEDLINE, PubMed and EMBASE) were searched from inception to April 27th, 2023 for studies investigating contralateral hamstring autografts in primary or revision ACLR. The authors adhered to the PRISMA and R-AMSTAR guidelines as well as the Cochrane Handbook for Systematic Reviews of Interventions. Data on demographics, strength measures, patient-reported outcome measures (PROMs), and rates of positive Lachman test, positive pivot-shift test and graft rupture were extracted. PROMs included Lysholm, International Knee Documentation Committee (IKDC) and Tegner scores.

RESULTS

Nine studies comprising 371 patients were included in this review. In primary ACLR, there were no significant differences between contralateral and ipsilateral groups in isokinetic hamstring torque in the non-ACLR limb or isokinetic quadriceps torque in both limbs when tested at 60, 90, 120 or 180 degrees/second. Isokinetic hamstring torque in the non-ACLR limb was significantly weaker in the contralateral group at six months for primary ACLR; however, these deficits did not persist. There were no significant differences in postoperative median Tegner scores and Lysholm scores between contralateral and ipsilateral groups in primary ACLR. There were no significant differences in postoperative median Tegner, mean Lysholm and IKDC scores between groups in revision ACLR. There were no significant differences in positive Lachman, positive pivot-shift and rupture rates in primary ACLR between groups. Rates of positive Lachman and pivot-shift were slightly higher in the contralateral than ipsilateral group for revision ACLR.

CONCLUSION

Contralateral hamstring autografts results in comparable muscle strength to ipsilateral hamstring autografts, with the exception of weaker hamstring strengths in the early postoperative period. Patient-reported outcome measures were similar between the two groups across both primary and revision ACLR, with rates of instability and failure being similar between groups for primary ACLR. Contralateral hamstring grafts do not provide additional benefit when compared to ipsilateral options for either primary or revision ACLR, and should be used only in select circumstances including insufficient ipsilateral hamstring grafts or situations where quadriceps or patella autografts are not optimal.

LEVEL OF EVIDENCE

Level IV.

The Risk Factors and Preventive Strategies of Poor Knee Functions and Osteoarthritis after Anterior Cruciate Ligament Reconstruction: A Narrative Review

Anterior cruciate ligament reconstruction (ACLR) is the standard surgical treatment for ACL injury, which typically uses a graft to replace the torn ligament in the knee that uses small incisions with minimally invasive surgery. The optimal knee functions following ACLR depend on rehabilitation processes before and after the surgery. Knee function is the ability of the knee to perform various types of functional movements like walking, squatting, running, jumping, and pivoting where patients expect to achieve maximum knee function or at least more than 80% of its initial condition before the injury to avoid being categorized as poor knee function after ACLR. Patients use patient-reported outcome measures to collect data on their health status and quality of life after ACLR. Post-traumatic osteoarthritis (PTOA) is a type of OA that manifests in local cartilage injury caused by chondrocyte death, and matrix dispersion occurs following a joint injury like ACL injury. Gender, time from injury to surgery, and graft type were considered as risk factors for poor knee function after ACLR, while overweight, meniscus tear, and cartilage defect as risk factors for PTOA. However, age is an internal risk factor for both poor knee function and PTOA following ACLR. This review suggests several strategies to prevent both conditions, including a pre-operative program, comprehensive rehabilitation, body weight control, and return to sport (RTS) consideration based on physical capacity, proper time, and psychological readiness.

Are We Jumping to the Wrong Conclusions? Longer Jumps and More Hops in Female Football Players Who Went on to Sustain a Primary or Secondary ACL Injury Compared to Those Who Did Not

BACKGROUND

Different functional performance tests are used to assess patients in the clinic and before return to sport (RTS), where the rehabilitation goal is to reach good strength and jumping ability. A limb symmetry index of ≥ 90% is a common target in rehabilitation before RTS. The aim of this short communication is to use data from our 2-year prospective cohort study on female football players, either with or without an anterior cruciate ligament (ACL) reconstruction, to discuss whether hop performance in 3 commonly used hop tests can inform safe football participation, that is, with a low risk for ACL injury or reinjury.

METHOD

At baseline, 117 active female football players (mean age ± standard deviation, 20 ± 2 years) were included 19 ± 9 months after ACL reconstruction as well as 119 matched female knee-healthy players (age 19 ± 3 years). All players performed a single hop for distance test, 5-jump test and side hop test at baseline and were then prospectively followed for 2 years. Twenty-eight (24%) players sustained a second ACL injury and 8 (7%) sustained a primary ACL injury.

RESULTS

Longer jumps in the 5-jump test (922 cm vs. 865 cm, Cohen's d =  - 0.60) and more hops in the side hop test for both limbs (41-42 hops vs. 33-36 hops, d =  - 0.43 to - 0.60) were seen in players who sustained a second ACL injury compared with those who did not. Longer jumps in the single hop for distance test (both limbs) (139-140 cm vs. 124-125 cm, d =  - 0.38 to - 0.44), in the 5-jump test (975 cm vs. 903 cm, d = -0.42) and more hops in the side hop test (both limbs) (48-49 hops vs. 37-38 hops, d =  - 0.38 to - 0.47) were seen in players who sustained a primary ACL injury compared with those who did not.

CONCLUSIONS

The average hop performance, i.e. longer jumps or more hops, was greater in players who went on to sustain a primary or secondary ACL injury compared to those who did not over a two-year follow-up period. Even though hop tests are not used in isolation to evaluate readiness to RTS, their interpretation needs consideration in the decision-making process of returning to pivoting sports.

A comparison between physical therapy clinics with high and low rehabilitation volumes of patients with ACL reconstruction

BACKGROUND

Treatment volume can impact outcomes after surgical procedures of the knee between surgeons with high- and low-patient-volumes. However, the difference between physical therapeutic clinics with high- and low-volumes has not been widely researched. This registry study aims to investigate how patient volume affects knee function outcomes after anterior cruciate ligament (ACL) reconstruction at physical therapy (PT) clinics in terms of odds for a second ACL injury, return to pre-injury level of activity, perceived knee function, and recovery of strength and hop performance.

METHOD

Data were extracted from the Project ACL, a local rehabilitation registry. High- and low-volume clinics were defined based on the number of patients who attended different clinics. High-volume clinics were defined as those with > 100 patient registrations in Project ACL during the study period while low-volume clinics were those with ≤ 100 patient registrations. High- and low-volume clinics were compared, based on muscle function and patient-reported outcomes across 4 follow-ups, 2-, 4-, 8-, and 12 months, during the first year after ACL reconstruction, and odds of second ACL injury up to 2 years after ACL reconstruction.

RESULT

Of the 115 rehabilitation clinics included, 111 were classified as low-volume clinics and included 733 patients, and 4 as high-volume clinics which included 1221 patients. There were 31 (1.6%) second ACL injuries to the ipsilateral or contralateral side within the first 12 months and 68 (4.0%) within 2 years. No difference in the incidence of a second ACL injury, within 12 months follow-up odds ratio (OR) 0.95 [95% CI 0.46-1.97] or within 2 years follow-up OR 1.13 [95% CI 0.68-1.88], was found between high- and low-volume clinics. There were early (2 months) and non-clinically relevant differences in patient-reported outcomes (PROs) and physical activity levels early after ACL reconstruction in favor of high-volume clinics. One year after ACL reconstruction, no differences were observed between high- and low-volume clinics in terms of PROs, muscle function, and return to pre-injury level of activity.

CONCLUSION

No clinically relevant difference in the incidence of secondary ACL injuries in patients who underwent rehabilitation after ACL reconstruction at high- or low-volume physical therapist clinics was found. In addition, no clinically relevant differences in outcomes were found during the first year in terms of patient-reported outcomes, recovery of muscle function, or return to pre-injury level of activity.

Clinical Outcomes After ACL Reconstruction in Soccer (Football, Futbol) Players: A Systematic Review and Meta-Analysis

CONTEXT

The risk factors for anterior cruciate ligament (ACL) tear for athletes participating in pivoting sports includes young age and female sex. A previous meta-analysis has reported a reinjury rate of 15% after ACL reconstruction (ACLR) for athletes across all sports. To the best of the authors' knowledge, this is the first systematic review and meta-analysis of available literature reporting outcomes after ACLR in soccer players.

OBJECTIVE

To review and aggregate soccer-specific outcomes data after ACLR found in current literature to help guide a more tailored discussion regarding expectations and prognosis for soccer players seeking operative management of ACL injuries.

DATA SOURCES

A comprehensive search of publications was performed using PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and SPORTDiscus databases.

STUDY SELECTION

Inclusion criteria consisted of original studies, level of evidence 1 to 4, studies reporting clinical and patient-reported outcomes (PROs) after primary ACLR in soccer players at all follow-up length.

STUDY DESIGN

The primary outcomes of interest were graft failure/reoperation rates, ACL injury in contralateral knee, return to soccer time, and PROs.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

Search of literature yielded 32 studies for inclusion that involved 3112 soccer players after ACLR.

RESULTS

The overall graft failure/reoperation rate ranged between 3.0% and 24.8% (mean follow-up range, 2.3-10 years) and the combined ACL graft failure and contralateral ACL injury rate after initial ACLR was 1.0% to 16.7% (mean follow-up range, 3-10 years); a subgroup analysis for female and male players revealed a secondary ACL injury incidence rate of 27%, 95% CI (22%, 32%) and 10%, 95% CI (6%, 15%), respectively. Soccer players were able to return to play between 6.1 and 11.1 months and the majority of PROs showed favorable scores at medium-term follow-up.

CONCLUSION

Soccer players experience high ACL injury rates after primary ACLR and demonstrated similar reinjury rates as found in previous literature of athletes who participate in high-demand pivoting sports.

Force plate jump testing metrics are predictive of performance on a multimodal return to sport testing protocol among anterior cruciate ligament reconstruction patients at minimum six-month follow-up

BACKGROUND

Force plate-based jump testing may serve as a potential alternative to traditional return to sport (RTS) testing batteries. The purpose of our study was to identify force plate jump metrics that were predictive of RTS test findings in patients who were at least six months postoperative following anterior cruciate ligament reconstruction (ACLR).

METHODS

We conducted a cross-sectional study of patients who underwent ACLR at our center and were at least six months postoperative. Subjects completed a multimodal Institutional RTS (IRTS) testing battery which included range of motion (ROM) testing and isokinetic quadriceps strength testing. Subjects also completed a countermovement jump testing protocol on a commercially-available force plate. Jump metrics predictive of IRTS test findings were identified using multivariable linear and logistic regression with stepwise selection. Model significance was assessed at α=0.002.

RESULTS

Sixteen patients (7M, 9F) were enrolled in our study with median age of 29 years (range 20-47). Relative concentric impulse was positively predictive of knee flexion active ROM (β=7.07, P=0.01) and passive ROM (β=9.79, P=0.003). Maximum power was positively predictive of quadriceps strength at 60 deg/s (β=3.27, P<0.001) and 180 deg/s (β=2.46, P<0.001). Center-of-pressure (COP) shift acceleration along the force plate X-axis was negatively predictive of Bunkie lateral test score (β=-945, P<0.001) and medial test score (β=-839, P=0.03).

CONCLUSIONS

Force plate-derived vertical jump testing metrics are predictive of certain components of a multimodal RTS physical assessment for ACLR patients, including knee flexion ROM, quadriceps strength on isokinetic testing, and Bunkie Test performance.

Detecting side-to-side differences of lower limb biomechanics during single-legged forward landing after anterior cruciate ligament reconstruction

BACKGROUND

Motion analysis can be used to evaluate functional recovery after anterior cruciate ligament (ACL) reconstruction; however, the biomechanics parameters of the lower limb that are specifically altered in ACL-reconstructed knees compared to the contralateral side are not well understood. This retrospective study aimed to compare side-to-side differences in lower limb biomechanics during the first 100 milliseconds (ms) after initial contact in a single-leg forward landing task.

METHODS

Using three-dimensional motion analysis, lower joint kinematic and kinetic variables were measured 8-10 months postoperatively in 22 patients who had undergone ACL reconstruction. We determined side-to-side differences in lower limb biomechanics over the 100-ms timeframe after landing, and receiver operating characteristic (ROC) curve analyses were performed to calculate the area under the curve (AUC) for parameters showing significant side-to-side differences.

RESULTS

During the 100-ms timeframe after landing, 58 kinematic and kinetic items showed significant side-to-side differences. Side-to-side differences in lower limb biomechanics over the 40-ms timeframe after landing existed. The ROC curve analysis identified 11 items with AUC values ≥ 0.70, including hip flexion, abduction moment, and knee joint power, and their AUC values were not significantly different.

CONCLUSION

Hip flexion/abduction moment and knee power after GRF max could be used as outcomes for assessing functional recovery in patients who have undergone ACL reconstruction.

Assessment of Return to Sport After ACL Reconstruction With Soft Tissue Autograft in Adolescent Athletes: Quadriceps Versus Hamstring Tendon

Background

Quadriceps tendon soft tissue autograft represents an increasingly popular graft option for anterior cruciate ligament reconstruction (ACLR), particularly for adolescents, some of whom have an open physis, precluding use of graft options with bone plugs.

Purpose/Hypothesis

The purpose of this study was to quantify return-to-sport performance assessments in adolescents at 6 months after ACLR with all-soft tissue quadriceps tendon autograft (ACLR-Q) versus hamstring tendon autograft (ACLR-HS). It was hypothesized that ACLR-Q would be associated with improved hamstring strength and hamstring-to-quadriceps (HS:Q) ratios compared with ACLR-HS, albeit with decreased quadriceps strength.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Included were patients aged 12 to 19 years who underwent primary ACLR by a single surgeon and who completed a return-to-sport performance assessment between 5 and 9 months postoperatively. The performance assessment included manual muscle strength tests (hamstring, quadriceps, hip abductor and adductor), dynamic balance test (Y-balance), and functional hop tests (single hop, triple hop, crossover hop, 6-m timed hop). Data were converted to limb symmetry indices, and limb symmetry index deficits were compared between the ACLR-Q and ACLR-HS cohorts using the Student t test or Wilcoxon-Mann-Whitney test.

Results

An initial cohort of 90 ACLR-Q patients was compared with 54 ACLR-HS patients, with no significant differences in patient characteristics. Differences in meniscal repair rates, however, prompted use of propensity score matching on age, sex, body mass index, meniscectomy, and meniscal repair to produce comparable subcohorts. The matching resulted in 67 ACLR-Q and 52 ACLR-HS patients. Hamstring strength deficits were significantly greater in ACLR-HS versus ACLR-Q patients (-40.5% vs -5.7%; P < .001). Quadriceps strength deficits were significantly greater in ACLR-Q versus ACLR-HS patients (-12.8% vs -0.4%; P < .001). ACLR-Q patients had a significantly greater HS:Q ratio on the operative knee (P < .001) and significantly higher Y-balance composite score deficits (-2.9% vs -0.4%; P = .01) than ACLR-HS patients. There were no significant differences in hop test performance between groups.

Conclusion

Adolescent athletes who underwent ACLR-Q showed significantly greater quadriceps strength deficits but significantly smaller hamstring strength deficits than those who underwent ACLR-HS, leading to more favorable HS:Q ratios in ACLR-Q patients at 6 months postoperatively.

Reconsideration of Return-to-Sport Decision-Making After Pediatric ACL Injury: A Scoping Review

CONTEXT

Up to 90% of pediatric athletes return to sport (RTS) after anterior cruciate ligament reconstruction (ACL-R); however, <50% RTS at the same level and second ACL injury rates are up to 32%.

OBJECTIVES

(1) Determine which physical and patient-reported outcome measures guide clinical decision-making on RTS in pediatric athletes after ACL-R and (2) present a framework with insights from cognitive and neurophysiological domains to enhance rehabilitation outcomes.

DATA SOURCES

PubMed, CINAHL, Embrase, and Cochrane library databases and gray literature.

STUDY SELECTION

Data on pediatric (<18 years) ACL-R patients, RTS, tests, and decision-making were reported in 1214 studies. Two authors independently reviewed titles and abstract, excluding 962 studies. Gray literature and cross-reference checking resulted in 7 extra studies for full-text screening of 259 studies. Final data extraction was from 63 eligible studies.

STUDY DESIGN

Scoping review.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

Details on study population, aims, methodology, intervention, outcome measures, and important results were collected in a data chart.

RESULTS

Studies included 4456 patients (mean age, 14 years). Quadriceps and hamstring strength (n = 25), knee ligament arthrometer (n = 24), and hop tests (n = 22) were the most-reported physical outcome measures guiding RTS in <30% of studies with cutoff scores of limb symmetry index (LSI) ≥85% or arthrometer difference <3 mm. There were 19 different patient-reported outcome measures, most often reporting the International Knee Documentation Committee (IKDC) (n = 24), Lysholm (n = 23), and Tegner (n = 15) scales. Only for the IKDC was a cutoff value of 85% reported.

CONCLUSION

RTS clearance in pediatric ACL-R patients is not based on clear criteria. If RTS tests were performed, outcomes did not influence time of RTS. Postoperative LSI thresholds likely overestimate knee function since biomechanics are impaired despite achieving RTS criteria. RTS should be considered a continuum, and biomechanical parameters and contextual rehab should be pursued with attention to the individual, task, and environment. There is a need for psychological monitoring of the ACL-R pediatric population.

Combining return to sport, psychological readiness, body mass, hamstring strength symmetry, and hamstring/quadriceps ratio increases the risk of a second anterior cruciate ligament injury

PURPOSE

To investigate the combinations of variables that comprise the biopsychosocial model domains to identify clinical profiles of risk and protection of second anterior cruciate ligament injury.

METHODS

One hundred and forty-five patients for return-to-sport testing after anterior cruciate ligament (ACL) reconstruction (ACLR) were contacted, and 97 were deemed eligible. All were evaluated between 6 and 24 months and followed up for 2 years. Participants answered the International Knee Documentation Committee (IKDC) and Anterior Cruciate Ligament-Return to Sport after Injury Scale (ACL-RSI), performed the postural stability assessment using the Biodex Balance System, and assessed muscle strength at 60° and 300°/s on the isokinetic dynamometer. Personal factors (age, gender, body mass index), body structures (graft type and concomitant injuries), and environmental factors (time between surgery and evaluation) were also collected. The participants were asked about the occurrence of a second ACL injury and return to sport after 2 years of follow-up. Classification and regression tree (CART) analysis was used to determine predictors of a second ACL injury. The receiver operating characteristic (ROC) curve was performed to verify the accuracy of the CART analysis, in addition to the sensitivity, specificity, and relative risk (RR) of the model.

RESULTS

Of the initial 97 participants, 88 (89.8%) responded to follow-up and 14 (15.9%) had a second ACL injury (11 graft ruptures and three contralateral ACL). CART analysis identified the following variables as predictors of second ACL injury: return to sport, hamstring strength symmetry at 300°/s, ACL-RSI score, hamstrings/quadriceps ratio at 60°/s, and body mass index (BMI). CART correctly identified 9 (64.3%) of the 14 participants who were reinjured and 71 (95.9%) of the 74 participants who were not. The total correct classification was 90.9%. The area under the ROC curve was 0.88 (95% CI 0.72-0.99; p < 0.001), and the model showed a sensitivity of 75% (95% CI 42.8-94.5), specificity of 93.4% (95% CI 85.3-97.8), and RR of 15.9 (95% CI 4.9-51.4; p < 0.0001).

CONCLUSION

The combination of hamstring strength symmetry, hamstring/quadriceps ratio (body functions); return to sport (activity and participation); psychological readiness; and BMI (personal factors) could identify three clinical risk profiles for a second ACL injury with good accuracy.

LEVEL OF EVIDENCE

IV.

Comparison of Strength and Power Characteristics Before ACL Rupture and at the End of Rehabilitation Before Return to Sport in Professional Soccer Players

BACKGROUND

Strength and power is often reduced on the involved versus contralateral limb and healthy controls after anterior cruciate ligament (ACL) reconstruction, but no study has compared with preinjury values at the time of return to sport (RTS).

HYPOTHESIS

Divergent recovery patterns in strength and power characteristics will be present at RTS relative to preinjury baseline data and healthy matched controls.

STUDY DESIGN

Cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Isokinetic strength tests, bilateral and single-leg countermovement jumps (CMJ; SLCMJ) were measured before ACL rupture in 20 professional soccer players. These then had surgical reconstruction (ACL group) and completed follow-up testing before RTS. Healthy controls (uninjured group) were tested at the same time as the ACL group preinjury. Values recorded at RTS of the ACL group were compared with preinjury. We also compared the uninjured and ACL groups at baseline and RTS.

RESULTS

Compared with preinjury, ACL normalized quadriceps peak torque of the involved limb (difference = -7%), SLCMJ height (difference = -12.08%), and Reactive Strength Index modified (RSImod) (difference = -5.04%) were reduced after ACL reconstruction. No significant reductions in CMJ height, RSImod, and relative peak power were indicated at RTS in the ACL group when compared with preinjury values, but deficits were present relative to controls. The uninvolved limb improved quadriceps (difference = 9.34%) and hamstring strength (difference = 7.36%) from preinjury to RTS. No significant differences from baseline were shown in SLCMJ height, power, and reactive strength of the uninvolved limb after ACL reconstruction.

CONCLUSION

Strength and power in professional soccer players at RTS after ACL reconstruction were often reduced compared with preinjury values and matched healthy controls.

CLINICAL RELEVANCE

Deficits were more apparent in the SLCMJ, suggesting that dynamic and multijoint unilateral force production is an important component of rehabilitation. Use of the uninvolved limb and normative data to determine recovery may not always be appropriate.

Utility of SpeedCourt System: A Novel Study of 100 Professional Footballers at FIFA Medical Centre of Excellence Dubai UAE

Purpose

The SpeedCourt system has been confirmed as an effective and dependable tool for evaluating multi-directional change-of-direction (COD) maneuvers. It has also been employed in the rehabilitation process following Anterior Cruciate Ligament (ACL) injuries and for multi-directional training purposes. This study investigated by means of the SpeedCourt system determines 1) whether there is any difference in COD parameters and countermovement jumps (CMJ) between United Arab Emirates (UAE) and non-UAE professional footballers 2) whether there is any difference between the two lower limbs during change-of-direction manoeuvres.

Methodology

This analysis included 100 professional football players from UAE or Non-UAE football clubs who were tested at FIFA Medical Centre of Excellence. With the help of Speedcourt system, 6-s tapping, countermovement jump (CMJ) and chase 15-s tests were performed. Comparison was done between UAE and non-UAE footballers and also between the dominant and non-dominant sides.

Results

Out of the 100 players, 83 players were right foot dominant. Apart from the countermovement jump test, there was no significant difference in results between UAE and non-UAE football players. Average time to turn for dominant and non-dominant sides did not show any significant difference, for either group.

Conclusion

There is no difference in 6-s tapping, Chase 15-s tests or limb asymmetry amongst UAE and Non-UAE footballers. However, the non-UAE footballers showed significantly better performance in Countermovement Jump Test. The data provide baseline values for forthcoming sports medicine research, which can be taken into account when creating injury prevention or return-to-sport protocols, particularly with regard to change of direction parameters and countermovement jump.

Clinical Utility of Ultrasound Imaging for Measuring Anterior Thigh Thickness after Anterior Cruciate Ligament Injury in an Individual Patient to Assess Postsurgery Outcome

The present study investigated the clinical utility of ultrasound imaging (USI) for assessing changes in an individual's quadriceps muscle and subcutaneous fat (SF) thickness of the anterior thigh and their relative proportions. A patient was studied prior to and after anterior cruciate ligament reconstruction (ACLR) surgery and during rehabilitation. This case study involved an 18-year-old female recreational athlete with a complete tear of the anterior cruciate ligament (ACL). Tissue thickness (SF and quadriceps muscle) was measured from transverse USI of the anterior thigh before surgery, at weekly intervals during 12 weeks of postsurgery, and then every 2 weeks for the following 12 weeks (total of 21 measurement sets). Statistically significant differences presurgery to postrehabilitation were found for muscle thickness (p = 0.04) and SF tissue thickness (p = 0.04) measurements. There was no difference in muscle to fat ratio (p = 0.08). Changes in measurements greater than the reported minimal detectable change (MDC) demonstrate the sensitivity of the USI technique as an objective tool to assess clinically useful changes in an individual's anterior thigh muscle thickness post-ACLR surgery and during rehabilitation.

The Role of Strength-Related Factors on Psychological Readiness for Return to Sport Following Anterior Cruciate Ligament (ACL) Reconstruction

Psychological readiness following anterior cruciate ligament reconstruction (ACLR) correlates with different return to sport outcomes. However, the relationship between strength and power and psychological readiness remains unexplored. The aim of this study was to investigate the relationship between anterior cruciate ligament return to sport after injury (ACL-RSI) scores and various hamstrings and quadriceps strength and power variables. Twelve participants (20.7 ± 2.5 years old; 174.2 ± 7.5 cm; 70.2 ± 8.5 kg; 18.2 ± 8.3% of body fat) who had an ACLR nine months or more before the study completed the ACL-RSI questionnaire and isokinetic strength testing of the hamstrings and quadriceps (60°·s-1 and 180°·s-1). Based on ACL-RSI scores, they were divided into "cases" and "controls", deemed not psychologically ready and psychologically ready to return to previous sport performance (PILOS), respectively. The main findings are that quadriceps' and hamstrings' rate of torque development (RTD) and time since surgery were determinants of psychological readiness following ACLR. Furthermore, compared to controls, cases showed significantly lower quadriceps torque at angles close to full knee extension (40 deg and 30 deg from extension). They also showed lower RTD than controls, but no difference in peak torque. These results suggest that physiotherapists should facilitate athletes' return to sport (RTS) by focusing on the restoration of RTD and strength at angles close to full knee extension.

Total Score of Athleticism: Profiling Strength and Power Characteristics in Professional Soccer Players After Anterior Cruciate Ligament Reconstruction to Assess Readiness to Return to Sport

BACKGROUND

There is no consensus on the optimal testing procedure to determine return-to-sport (RTS) readiness after anterior cruciate ligament (ACL) reconstruction. Current approaches use limb symmetry across a range of tests, but this does not consider a patient's level of athleticism or benchmarks relative to his or her noninjured counterparts.

PURPOSE

To examine the utility of the Total Score of Athleticism (TSA), a composite scale including strength, power, and reactive strength assessments, to aid RTS decision-making.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 95 professional soccer players (60 who underwent ACL reconstruction [mean age, 25.1 ± 12.6 years] and 35 who were uninjured [mean age, 23.8 ± 2.8 years]) completed a battery of tests including isokinetic knee extension and flexion torque, bilateral and unilateral countermovement jump height, relative peak power, and reactive strength index-modified. The TSA score (derived from Z scores) was calculated, and we (1) examined differences between the ACL-reconstructed and uninjured groups at the time of RTS, (2) assessed the predictive ability of the TSA to identify the player's status (ACL reconstruction vs uninjured control), and (3) included a case series to discuss the characteristics of players who sustained a subsequent injury within 4 months after RTS.

RESULTS

A large difference between the ACL-reconstructed and uninjured groups in the TSA score (d = 0.84; P < .0001) was evident. For every additional increase of 1 unit in the TSA score, the odds of belonging to the ACL-reconstructed group decreased by 74% (95% CI, 0.19-0.56). By visual inspection, the frequency of reinjured players was higher in the low (4/7) TSA tertile compared with the medium (2/7) and high (1/7) TSA tertiles.

CONCLUSION

Preliminary evidence indicates that the TSA may be a useful RTS readiness tool, as the composite score derived from strength and power measures was different in soccer players at the time of RTS after ACL reconstruction compared with healthy matched controls. There was also a higher frequency of low TSA scores in players who sustained a second injury after RTS. Therefore, it is recommended to routinely administer RTS tests encompassing strength, power, and reactive strength qualities each season across the largest possible number of players (ideally teammates).

Hop to It! The Relationship Between Hop Tests and The Anterior Cruciate Ligament - Return to Sport Index After Anterior Cruciate Ligament Reconstruction in NCAA Division 1 Collegiate Athletes

Background

Outcomes after anterior cruciate ligament reconstruction (ACLR) may not be optimal, with poor physical and psychological function potentially affecting return to sport (RTS) ability. Understanding the relationship between commonly used hop tests and the Anterior Cruciate Ligament - Return to Sport Index (ACL-RSI) may improve rehabilitation strategies and optimize patient outcomes.

Hypothesis/Purpose

The purpose of this study was to examine the relationship between ACL-RSI scores and limb symmetry index (LSI) for the single hop for distance (SHD), triple hop for distance (THD), crossover hop for distance (CHD), timed 6-meter hop (T6H), and single leg vertical hop (SLVH) in a cohort of National Collegiate Athletic Association (NCAA) Division 1 collegiate athletes after ACLR. The hypothesis was that SLVH LSI would be more highly correlated with ACL-RSI score than all horizontal hop tests.

Study design

Cross-Sectional Study.

Methods

Twenty-one National Collegiate Athletic Association (NCAA) Division 1 collegiate athletes (7 males, 14 females) at 6.62 ± 1.69 months after ACLR were included in this retrospective study. Primary outcomes were ACL-RSI score and LSI for SHD, THD, CHD, T6H, and SLVH. The relationship between ACL-RSI scores and performance on hop tests (LSIs) was evaluated using correlation analysis and step-wise linear regression (p ≤ 0.05).

Results

There were significant correlations found when comparing ACL-RSI and the LSI for SHD (rs = 0.704, p < 0.001), THD (rs = 0.617, p = 0.003), CHD (rs = 0.580, p = 0.006), and SLVH (rs = 0.582, p = 0.006). The CHD explained 66% (R2 value of 0.660) of the variance in the ACL-RSI, while the other hop tests did not add to the predictive model.

Conclusions

Physical function has the capacity to influence psychological status after ACLR. Clinicians should recognize that SLVH, SHD, THD, and CHD are correlated with ACL-RSI and improvements in physical function during rehabilitation may improve psychological status and optimize RTS after ACLR.

Level of evidence

Level 3.

Clinical Commentary: A Criteria-Based Testing Protocol for Return to Sport Post Hip Arthroscopy for Impingement

Overall, 84%-87% of athletes will return to sport following hip arthroscopy; however, some literature suggests that only 57% of athletes return to their preinjury level, and only 16.9% report optimal performance. This discrepancy may be due to a lack of consistency within the definition of return to sport as well as a lack of consistency within rehabilitation programs when determining return to sport readiness. Athletes who are returning to sport must demonstrate adequate range of motion, strength, and the ability to perform multi-directional movements without the risk of reinjury. There has yet to be a comprehensive, criteria-based, return to sport testing protocol that utilizes objective measures to ensure athletes are ready for return to sport. The goal of the authors was to create a criteria-based testing protocol for return to sport following hip arthroscopy utilizing components best supported in the literature. The following parameters were identified as key areas to assess for within a return to sport testing protocol: range of motion, strength, functional testing, self-reported outcomes including psychological readiness and time. The purpose of this clinical commentary is to propose a criteria-based testing protocol to be used following hip arthroscopy for impingement from early rehabilitation through return to previous level of sport. Criteria are presented clearly to promote objective progression through rehabilitation while still being mindful of the biological healing time required for safe and efficient progression. It is the authors' hope that in identifying and establishing a criteria-based testing protocol a higher percentage of athletes will be able to return to sport.

Level of Evidence

5.

The Influence of Quadriceps Strength and Rate of Torque Development on the Recovery of Knee Biomechanics During Running After Anterior Cruciate Ligament Reconstruction

BACKGROUND

After anterior cruciate ligament reconstruction (ACLR), altered surgical knee biomechanics during running is common. Although greater quadriceps strength is associated with more symmetrical running knee kinetics after ACLR, abnormal running mechanics persist even after resolution of quadriceps strength deficits. As running is a submaximal effort task characterized by limited time to develop knee extensor torque, quadriceps rate of torque development (RTD) may be more closely associated with recovery of running knee mechanics than peak torque (PT).

PURPOSE

To assess the influence of recovery in quadriceps PT and RTD symmetry on knee kinematic and kinetic symmetry during running over the initial 2 years after ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 39 Division I collegiate athletes (106 testing sessions; 19 female) completed serial isometric performance testing and running analyses between 3 and 24 months after ACLR. Athletes performed maximal and rapid isometric knee extension efforts with each limb to assess PT and RTD between-limb symmetry indices (PTLSI and RTDLSI), respectively. Peak knee flexion difference (PKFDIFF) and peak knee extensor moment limb symmetry index (PKEMLSI) during running were computed. Multivariable linear mixed-effects models assessed the influence of PTLSI and RTDLSI on PKFDIFF and PKEMLSI over the initial 2 years after ACLR.

RESULTS

Significant main effects of RTDLSI (P < .001) and time (P≤ .02) but not PTLSI (P≥ .24) were observed for both PKFDIFF and PKEMLSI models. For a 10% increase in RTDLSI, while controlling for PTLSI and time, a 0.9° (95% CI, 0.5°-1.3°) reduction in PKFDIFF and a 3.5% (95% CI, 1.9%-5.1%) increase in PKEMLSI are expected. For every month after ACLR, a 0.2° (95% CI, 0.1°-0.4°) reduction in PKFDIFF and a 1.3% (95% CI, 0.6%-2.0%) increase in PKEMLSI are expected, controlling for PTLSI and RTDLSI.

CONCLUSION

Quadriceps RTDLSI was more strongly associated with symmetrical knee biomechanics during running compared with PTLSI or time throughout the first 2 years after ACLR.

It is time to target psychological readiness (or lack of readiness) in return to sports after Anterior Cruciate Ligament tears

Functional recovery has for long been the focus of rehabilitation after an Anterior Cruciate Ligament (ACL) injury. It is now increasingly recognized that more attention should be given to patients` mental recovery, their psychological readiness for returning to sport, after such an injury. Within this relatively new field of science, clinicians need clarity on when and how psychological factors should be monitored and how inexpedient psychological responses may be addressed during rehabilitation. In this Expert Opinion suggestions on how targeting psychological readiness may improve rehabilitation and return-to-sport evaluations are made based on current evidence-and issues in need of further clarification are addressed.

Development and Reliability of a Visual-Cognitive Reactive Triple Hop Test

CONTEXT

Current lower-extremity return to sport testing primarily considers the physical status of an athlete; however, sport participation requires continuous cognitive dual-task engagement. Therefore, the purpose was to develop and evaluate the reliability of a visual-cognitive reactive (VCR) triple hop test that simulates the typical sport demand of combined online visual-cognitive processing and neuromuscular control to improve return to sport testing after lower-extremity injury.

DESIGN

Test-retest reliability.

METHODS

Twenty-one healthy college students (11 females, 23.5 [3.7] y, 1.73 [0.12] m, 73.0 [16.8] kg, Tegner Activity Scale 5.5 [1.1] points) participated. Participants performed a single-leg triple hop with and without a VCR dual task. The VCR task incorporated the FitLight system to challenge peripheral response inhibition and central working memory. Maximum hop distance, reaction time, cognitive errors, and physical errors were measured. Two identical testing visits were separated by 12 to 17 days (14 [1] d).

RESULTS

Traditional triple hop (intraclass correlation coefficients: ICC(3,1) = .96 [.91-.99]; standard error of the measurement = 16.99 cm) and the VCR triple hop (intraclass correlation coefficients(3,1) = .92 [.82-.97]; standard error of the measurement = 24.10 cm) both demonstrated excellent reliability for the maximum hop distance, and moderate reliability for the VCR triple hop reaction time (intraclass correlation coefficients(3,1) = .62 [.09-.84]; standard error of the measurement = 0.09 s). On average, the VCR triple hop resulted in a hop distance deficit of 8.17% (36.4 [5.1] cm; P < .05, d = 0.55) relative to the traditional triple hop.

CONCLUSIONS

Hop distance on the VCR triple hop had excellent test-retest reliability and induced a significant physical performance deficit when compared with the traditional triple hop assessment. The VCR triple hop reaction time also demonstrated moderate reliability.

Quadriceps Performance and Running Biomechanics Influence Femur BMD Changes after ACL Reconstruction in Collegiate Athletes

PURPOSE

Reduced bone mineral density of the distal femur (BMD DF ) can persist long term after anterior cruciate ligament reconstruction (ACLR), even in athletes who return to high levels of competition. These deficits may have implications for the onset and progression of knee osteoarthritis. It is unknown if clinically modifiable factors are associated with losses in BMD DF . This study evaluated the potential influence of knee extensor peak torque (PT), rate of torque development (RTD), as well as peak knee flexion (PKF) angle and peak knee extensor moment (PKEM) during running, on longitudinal changes in BMD DF post-ACLR.

METHODS

After ACLR, 57 Division I collegiate athletes underwent serial whole-body dual-energy x-ray absorptiometry (DXA) scans between 3 and 24 months post-ACLR. Of these, 43 athletes also had isometric knee extensor testing (21 female, 105 observations), and 54 had running analyses (26 female, 141 observations). Linear mixed-effects models, controlling for sex, assessed the influence of surgical limb quadriceps performance (PT and RTD), running mechanics (PKF and PKEM), and time post-ACLR on BMD DF (5% and 15% of femur length). Simple slope analyses were used to explore interactions.

RESULTS

Athletes with RTD less than 7.20 (N·m)·kg -1 ·s -1 (mean) at 9.3 months post-ACLR demonstrated significant decreases in 15% BMD DF over time ( P = 0.03). Athletes with PKEM during running less than 0.92 (N·m)·kg -1 (-1 SD below mean) at 9.8 months post-ACLR demonstrated significant decreases in 15% BMD DF over time ( P = 0.02). Significant slopes were not detected at -1 SD below the mean for PT (1.75 (N·m)·kg -1 , P = 0.07) and PKF (31.3°, P = 0.08).

CONCLUSIONS

Worse quadriceps RTD and running PKEM were associated with a greater loss of BMD DF between 3 and 24 months post-ACLR.

Evaluating a Wearable Solution for Measuring Lower Extremity Asymmetry During Landing

Purpose

Force plates can be used to monitor landing asymmetries during rehabilitation, but they are not widely available. Accelerometer-based wearable technology may be a more feasible solution. The purpose of this article was to determine the agreement between impact accelerations measured with force plates and accelerometer-derived measures of (1) centre of mass (COM) acceleration and (2) tibial acceleration asymmetries during bilateral landings.

Method

Participants completed three countermovement jumps (CMJ) and three squat jumps (SJ) on dual force plates with triaxial accelerometers attached to each tibia and lower back, near the COM. Bland and Altman 95% limits of agreement (95% LOA) were calculated.

Results

19 adults (n = 11; 58% women, n = 8; 42% men) participated in the study. The mean differences between impact and COM accelerations were 0.24 g (95% LOA: -1.34 g to 1.82 g) and 0.38 g (95% LOA: -1.15 to 1.91 g) for the CMJ and SJ, respectively. The mean differences between the impact and tibial acceleration-based lower limb asymmetries in the CMJ and SJ were -6% (95% LOA: -32% to 19%) and 0% (95% LOA: -45% to 45%), respectively.

Conclusions

Our findings show acceptable agreement between impact acceleration and accelerometer-based COM acceleration and lack of agreement between impact accelerations and accelerometer-based tibial acceleration asymmetries. COM acceleration could be used to quantify landing impacts during rehabilitation, but we do not consider the accelerometer-based asymmetry measures to be a suitable alternative for force plate-based measures. Future work should focus on determining normative values for lower extremity asymmetries during landing tasks.

Five-times sit-to-stand test following anterior cruciate ligament surgery: a cross-sectional reliability study

Aims

Patients who have had anterior cruciate ligament reconstruction (ACL-R) should periodically have their muscle strength assessed. The five-times sit-to-stand test (FTSST) can evaluate the muscle strength and balance of the lower extremities. This study's primary purpose was to assess the validity and reliability of the FTSST in patients who have undergone ACL-R.

Material and Methods

Forty-three people who had undergone ACL-R surgery were included in the study. The study's primary outcome measure, the FTSST, was assessed by two different investigators. Secondary outcome measures were body balance, quadriceps muscle strength, Tegner activity score (TAS), and Lysholm score.

Results

The FTSST's test-retest and inter-rater reliability were both high (ICC: 0.99). The FTSST also showed a strong statistically significant correlation with all secondary outcome measures, including balance, quadriceps muscle strength, TAS, and Lysholm score (p<0.05).

Conclusions

According to the study results, the FTSST is a tool-free, simple method for assessing muscle strength and the body balance level, mobility level, and functional status of the knee in patients who have undergone ACL-R surgery.

Feasibility of return to sports assessment 6 months after patellar instability surgery

BACKGROUND

The evidence regarding the usefulness of assessment tools to support decisions of return-to-sport after surgery for patellar instability is scarce. The purpose of this study was therefore to explore the feasibility of functional tests assessing readiness for return-to-sport six months after patellar stabilizing surgery. However, there is little evidence on what a functional assessment should include to support these decisions following surgery for patellar instability. Therefore the purpose of this study was to explore the feasibility of functional tests assessing readiness for return-to-sport six months after patellar stabilizing surgery.

METHODS

In this cross-sectional study a prospective cohort of 78 patients were subjected to a range of return-to-sport readiness tests at six months after surgery for patellar instability with an "a la carte" approach. Lower Quarter Y-Balance Test (YBT-LQ), single-legged hop tests and isokinetic strength tests were performed. In addition, self-reported function was measured with the Banff Patellofemoral Instability Instrument 2.0 (BPII) and Norwich Patellar Instability score (NPI). Return-to-sport clearance criteria were defined as: ≤4 cm YBT-LQ anterior reach difference between legs, leg-symmetry-index (LSI) ≥ 95% in the YBT-LQ composite score, mean sum score LSI ≥ 85% of all single-leg hop tests and LSI ≥ 90% in isokinetic quadriceps strength.

RESULTS

Sixty-four patients (82%) were able to complete all functional tests, while only eleven (14%) patients were deemed ready for return-to-sport, passing all return-to-sport clearance criteria. Patients with bilateral problems demonstrated worse performance in the contralateral leg, which resulted in higher LSI scores compared to individuals with unilateral instability. A supplementary finding was that the extent of surgery (MPFL-R only versus combined surgery) did not predict and mainly did not affect self-reported function or functional performance at the follow-up.

CONCLUSION

The functional assessment used in the current study seems feasible to conduct at six months after patellar stabilizing surgery. However, current suggested clearance standards and the use of leg-symmetry-index seems inappropriate for patients with patellar instability. Therefore, further exploration of appropriate tests and return-to-sport clearance criteria is justified.

TRIAL REGISTRATION

clinicaltrial.gov, NCT05119088. Registered 12.11.2021 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT05119088 .

Call for the application of a biopsychosocial and interdisciplinary approach to the return-to-sport framework of snow sports athletes

Snow sports such as alpine skiing or snowboarding are associated with a high risk of injury and reinjury and are subject to a very special environment with specific rehabilitation challenges that must be addressed. Due to geographic decentralisation, seasonal climatic limitations, alternation of training in off-snow and on-snow settings and unique loading patterns of practising these sports, special rehabilitation structures and processes are required compared with other sports. In addition, returning to preinjury performance requires a high level of confidence and a resumption of risk-taking in demanding situations such as high-speed skiing and high-amplitude jumps. A biopsychosocial and interdisciplinary approach can be viewed as a holistic, athlete-centred approach that promotes interprofessional communication and collaboration. This is particularly central for managing the physical/biological, psychological and social demands of injury management for snow sports. It can help ensure that rehabilitation content is well coordinated and tailored to individual needs. This is because transitions between different rehabilitation phases and caring professionals are well aligned, and rehabilitation is understood not only as purely 'physical recovery' but also as 'psychological recovery' considering the snow sports-specific setting with specific social norms. Ultimately, this may improve the rehabilitation success of snow sports athletes.

Lower rates of return to sport in patients with generalised joint hypermobility two years after ACL reconstruction: a prospective cohort study

BACKGROUND

Generalised joint hypermobility (GJH) has been associated with an increased risk of suffering an anterior cruciate ligament (ACL) injury. Patients with GJH exhibit lower muscle strength and poorer scores for patient-reported outcomes after ACL reconstruction, compared with patients without GJH. The aim of this study was to examine differences in the percentages of patients who return to sport (RTS) or pre-injury level of activity (RTP), muscle function and patient-reported outcomes at the time of RTS or RTP, as well as the time of RTS or RTP in patients with GJH compared with patients without GJH in the first two years after ACL reconstruction.

METHODS

This prospective study used data from an ACL- and rehabilitation-specific register located in Gothenburg, Sweden. Patients aged between 16 and 50, who had a primary ACL injury treated with reconstruction, were included. Data up to two years after ACL reconstruction were used and consisted of achieving RTS and RTP, results from isokinetic muscle function tests for knee extension and flexion and patient-reported outcomes (Knee Self-Efficacy Scale, Knee injury and Osteoarthritis Outcome Score and ACL-Return to Sport after Injury scale) at the time of RTS, as well as the time of RTP. A Beighton Score of ≥ 5/9 was used to define GJH. A Tegner Activity Scale of ≥ 6 was used to define RTS, while a Tegner equal to or above pre-injury level was used to define RTP.

RESULTS

A total of 1,198 patients (54.7% women) with a mean age of 28.5 ± 8.6 years were included. A smaller proportion of patients with GJH achieved RTS compared with patients without GJH (49.2% vs. 57.3%, Odds ratio: 0.720, p = 0.041). Furthermore, patients with GJH were marginally less symmetrical on the knee extension strength test, expressed as a Limb Symmetry Index, at the time of RTP compared with patients without GJH (87.3 ± 13.5 vs. 91.7 ± 14.3, Cohen's d = 0.142, p = 0.022). No further differences were found between groups regarding any muscle function tests or patient-reported outcomes.

CONCLUSION

A smaller proportion of patients with GJH achieved RTS compared with patients without GJH. Patients with GJH displayed less symmetrical knee extension strength at the time of RTP compared with patients without GJH.

Anterior Cruciate Ligament Injury Prevention and Rehabilitation

At all levels of American football, knee injuries are common, with injuries to the anterior cruciate ligament (ACL) making up a significant proportion. Historically, ACL injuries were career-altering for professional players, but innovative techniques in surgery and rehabilitation have returned many to the field. While there is a consensus on surgical techniques for ACL reconstruction, significant discrepancies remain on injury prevention and rehabilitation programs. This review article describes the burden of ACL injury on players in the National Football League, best practices in injury prevention and rehabilitation, and evidence-based recommendations for preparing injured athletes to return to play.

Generalised joint hypermobility leads to increased odds of sustaining a second ACL injury within 12 months of return to sport after ACL reconstruction

OBJECTIVES

To determine the 12-month risk of a second anterior cruciate ligament (ACL) injury in a population of patients with and without generalised joint hypermobility (GJH) who return to sports (RTS) at competition level after ACL reconstruction (ACL-R).

METHODS

Data were extracted from a rehabilitation-specific registry for 16-50-year-old patients treated with ACL-R between 2014 and 2019. Demographics, outcome data and the incidence of a second ACL injury within 12 months of RTS, defined as a new ipsilateral or contralateral ACL, were compared between patients with and without GJH. Univariable logistic regression and Cox proportional hazards regression were performed to determine the influence of GJH and time of RTS on the odds of a second ACL injury, and ACL-R survival without a second ACL injury after RTS.

RESULTS

A total of 153 patients, 50 (22.2%) with GJH and 175 (77.8%) without GJH, were included. Within 12 months of RTS, 7 (14.0%) patients with GJH and 5 (2.9%) without GJH had a second ACL injury (p=0.012). The odds of sustaining a second ipsilateral or contralateral ACL injury were 5.53 (95% CI 1.67 to 18.29) higher in patients with GJH compared with patients without GJH (p=0.014). The lifetime HR of a second ACL injury after RTS was 4.24 (95% CI 2.05 to 8.80; p=0.0001) in patients with GJH. No between-group differences were observed in patient-reported outcome measures.

CONCLUSION

Patients with GJH undergoing ACL-R have over five times greater odds of sustaining a second ACL injury after RTS. The importance of joint laxity assessment should be emphasised in patients who aim to return to high-intensity sports following ACL-R.

Walking speed differentially affects lower extremity biomechanics in individuals with anterior cruciate ligament reconstruction compared to uninjured controls

BACKGROUND

Walking biomechanics are commonly affected after anterior cruciate ligament reconstruction and differ compared to uninjured controls. Manipulating task difficulty has been shown to affect the magnitude of walking impairments in those early after knee surgery but it is unclear if patients in later phases post-op are similarly affected by differing task demands. Here, we evaluated the effects of manipulating walking speed on between-limb differences in ground reaction force and knee biomechanics in those with and without anterior cruciate ligament reconstruction.

METHODS

We recruited 28 individuals with anterior cruciate ligament reconstruction and 20 uninjured control participants to undergo walking assessments at three speeds (self-selected, 120%, and 80% self-selected speed). Main outcomes included sagittal plane knee moments, angles, excursions, and ground reaction forces (vertical and anterior-posterior).

FINDINGS

We observed walking speed differentially impacted force and knee-outcomes in those with anterior cruciate ligament reconstruction. Between-limb differences increased at fast and decreased at slow speeds in those with anterior cruciate ligament reconstruction while uninjured participants maintained between-limb differences regardless of speed (partial η2 = 0.13-0.33, p < 0.05). Anterior cruciate ligament reconstruction patients underloaded the surgical limb relative to both the contralateral, and uninjured controls in GRFs and sagittal plane knee moments (partial η2 range = 0.13-0.25, p < 0.05).

INTERPRETATION

Overall, our findings highlight the persistence of walking impairments in those with anterior cruciate ligament reconstruction despite completing formal rehabilitation. Further research should consider determining if those displaying larger changes in gait asymmetries in response to fast walking also exhibit poorer strength and/or joint health outcomes.

[Return to Sport (RTS) After Anterior Cruciate Ligament Reconstruction: Which Factors Influence the RTS Decision?]

BACKGROUND

It is unknown which valid criteria should be considered to justify the decision for return to sport (RTS) following anterior cruciate ligament reconstruction (ACLR). The research question is whether gender, age, the outcome of the isokinetic maximal strength measurement and the single-leg hop test (quantitative/qualitative) influence the decision for RTS nine months after ACLR.

METHODS

This study is a retrospective data analysis. The research question was evaluated with a multiple logistic regression analysis (MLR). The dependent variable, RTS yes/no, is based on the decision of the orthopaedist in charge of treatment nine months (±30 days) after ACLR. The following possible influencing factors were investigated: gender, age, limb symmetry index (LSI) of maximal knee extension and knee flexion strength at 60°/sec., LSI of single-leg hop test and evaluation of knee valgus.

RESULTS

Data of 71 patients were included for MLR. The odds ratios (OR) for RTS increased with female gender (OR, 4.808; p=0.035), a higher LSI of maximal strength of knee extension (OR, 1.117; p=0.009) and a higher LSI of the single-leg hop test (OR, 1.125; p=0.020). Age, the LSI of maximal strength of knee flexion and knee valgus had no influence on the RTS decision.

CONCLUSION

Gender and the limb symmetry indexes of the maximal strength of knee extension and of the single-leg hop test are associated with RTS nine months after ACLR. These results should be considered to optimise rehabilitation after ACLR.