Hop testing symmetry improves with time and while wearing a functional knee brace in anterior cruciate ligament reconstructed athletes

Athletes Continue to Show Functional Performance Deficits at Return to Sport After Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To systematically review the existing literature on the functional performance of athletes at the time of return-to-sport (RTS) clearance after anterior cruciate ligament reconstruction (ACLR).

METHODS

A systematic literature search of the MEDLINE, EMBASE, Scopus, and Web of Science databases was performed. The inclusion criteria were original research reports with study populations of athletes who had undergone ACLR and had undergone objective functional testing immediately after clearance to RTS. Functional testing was stratified by hop tests, strength tests, kinetic assessment, and kinematic assessment, and data were extracted from each study using a standardized template.

RESULTS

Of the 937 unique studies identified, 46 met the inclusion criteria. The average time between ACLR and functional testing was 7.9 months among the included studies. In 10 of 17 studies, patients were found to have an average quadriceps strength limb symmetry index of less than 90%. However, only 2 of 12 studies found the average hop test limb symmetry index to be less than 90%. Kinematics included reduced knee flexion angle and increased trunk flexion on landing in ACLR patients compared with matched controls. On evaluation of kinetics, ACLR patients showed reduced peak vertical ground reaction force, lower peak knee extension and knee flexion moments, and altered energy absorption contribution compared with matched controls.

CONCLUSIONS

This systematic review suggests that athletes show functional deficits at the time of RTS at an average of 7.9 months after ACLR. Traditional functional tests, such as strength and hop tests, are not able to accurately identify patients who continue to show deficits. The most common biomechanical deficits that persist after RTS clearance include diminished peak knee extension moment, decreased knee flexion angle, increased trunk flexion angle, reduced vertical ground reaction force, and increased hamstring central activation ratio during various functional gait and landing tasks.

LEVEL OF EVIDENCE

Level III, systematic review of Level I to III studies.

Validity, reliability, and bias between instrumented pedals and loadsol insoles during stationary cycling

The purpose of this study was to evaluate the validity and reliability of the loadsol in measuring pedal reaction force (PRF) during stationary cycling as well as lower limb symmetry. Ten healthy participants performed bouts of cycling at 1kg, 2kg, and 3kg workloads (conditions) on a cycle ergometer. The ergometer was fitted with instrumented pedals and participants wore loadsol plantar pressure insoles. A 3 x 2 (Condition x Sensor Type) ANOVA was used to examine the differences in measured peak PRF, impulse, and symmetry indices. Root mean square error, intraclass correlation coefficients, and Passing-Bablok regressions were used to further assess reliability and validity. The loadsol demonstrated poor (< 0.5) to excellent (> 0.9) agreement as measured by intraclass correlation coefficients for impulse and peak PRF. Passing-Bablok regression revealed a systematic bias only when assessing all workloads together for impulse with no bias present when looking at individual workloads. The loadsol provides a consistent ability to measure PRF and symmetry when compared to a gold standard of instrumented pedals but exhibits an absolute underestimation of peak PRF. This study provides support that the loadsol can identify and track symmetry differences in stationary cycling which means there is possible usage for clinical scenarios and interventions in populations with bilateral asymmetries such as individuals with knee replacements, limb length discrepancies, diabetes, or neurological conditions. Further investigation of bias should be conducted in longer cycling sessions to ensure that the loadsol system is able to maintain accuracy during extended use.

The Association of Physical Competence With Psychological Response Among Young Athletes at Time of Return to Sport After ACL Reconstruction

BACKGROUND

The traditional index of return-to-sport (RTS) readiness after anterior cruciate ligament reconstruction (ACLR) is the achievement of physical competence criteria. Emerging research indicates that psychological response and self-perceptions of physical competence may be critical mechanisms for successful RTS among young athletes.

HYPOTHESIS

Young athletes with higher actual physical competence (APC) and perceived physical competence (PPC) will demonstrate a more positive psychological response at the time of RTS after ACLR.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 41 young athletes after primary ACLR completed testing within 8 weeks of medical clearance to RTS. APC was measured with isokinetic knee extension strength, single-limb crossover hop for distance, and the Knee injury and Osteoarthritis Outcome Score. PPC was measured with the Athletic Competence subscale of the Self-Perception Profile. Criteria for APC and PPC were based on established age- and activity-relevant cutoff scores. Different constructs of psychological response were assessed with the adapted Sport Motivation Scale, Brief Resilience Scale, and Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) total and subscale scores (Emotions, Confidence, and Risk Appraisal). Multiple linear regression analyses were used to determine differences in measures of psychological response based on achievement of APC and PPC, while adjusting for age and sex.

RESULTS

Of the 41 participants, 10 (24.4%) met all criteria for APC and 22 (53.7%) met the PPC criteria. The regression models estimating the ACL-RSI score (P < .001; adjusted R2 = 0.331), ACL-RSI Emotions score (P < .001; adjusted R2 = 0.427), and ACL-RSI Risk Appraisal score (P = .013; adjusted R2 = 0.212) were statistically significant. Although APC was not associated with any measure of psychological response, meeting PPC criteria, younger age, and male sex were found to be associated with a more positive psychological readiness to RTS, but not with motivation or resilience.

CONCLUSION

Meeting PPC criteria was associated with higher psychological readiness to RTS among young athletes after ACLR, while meeting APC criteria was not associated with any construct of psychological response.

Novel Use of an Accelerometer to Assess Load Asymmetry Over Time After Hip Resurfacing Arthroplasty

INTRODUCTION

There is limited knowledge regarding usage of wearable technology to guide return to sport after hip resurfacing arthroplasty (HRA). This study evaluated the use of accelerometers to identify when symmetry is restored between operative and non-operative limbs.

METHODS

A total of 26 primary HRA patients performed five validated physical tests before, 3 and 6 months after HRA: broad jump, double leg vertical jump (DLVJ), hop test, lateral single leg jump (LSLJ), and vertical single leg jump (VSLJ). Impact load and average intensity data (g-force units) were collected using accelerometers. Strength data (pounds (lbs.)) for internal and external rotation was collected with a dynamometer. Univariate and correlation analyses analyzed interlimb asymmetries.

RESULTS

At pre-operation, there were significant impact load asymmetries for DLVJ (P=.008), hop test (P=.021), and LSLJ (P=.003), and intensity asymmetry for DLVJ (P=.010) and LSLJ (P=.003). At 3 months, there was impact load asymmetry for DLVJ (P=.005) and LSLJ (P=.005), and intensity asymmetry for broad jump (P=.020), hop test (P=.042), and LSLJ (P=.005). There were significant strength asymmetries at pre- and 3 months post-operation for internal (P=.013) and external rotation (P=.037). All significant asymmetries indicated the non-operative leg had greater output. No significant asymmetries were found for any exercises at 6 months post-operation. An increase in Harris Hip Score was significantly associated with a decrease in impact asymmetry (r_s = -0.269, P=.006).

DISCUSSION AND CONCLUSION

Impact loads and strength reach interlimb symmetry at 6 months post-HRA. Wearable accelerometers provide useful metrics to distinguish limb asymmetries for recovery monitoring.

The Calculation, Thresholds and Reporting of Inter-Limb Strength Asymmetry: A Systematic Review

The prevalence of inter-limb strength differences is well documented in the literature however, there are inconsistencies related to measurement and reporting, and the normative values and effects associated with inter-limb asymmetry. Therefore, the aims of this systematic review were to: 1) assess the appropriateness of existing indices for the calculation of asymmetry, 2) interrogate the evidence basis for literature reported thresholds used to define asymmetry and 3) summarise normative levels of inter-limb strength asymmetry and their effects on injury and performance. To conduct this systematic review, scientific databases (PubMed, Scopus, SPORTDiscus and Web of Science) were searched and a total of 3,594 articles were retrieved and assessed for eligibility and article quality. The robustness of each identified asymmetry index was assessed, and the evidence-basis of the identified asymmetry thresholds was appraised retrospectively using the references provided. Fifty-three articles were included in this review. Only four of the twelve identified indices were unaffected by the limitations associated with selecting a reference limb. Eighteen articles applied a threshold to original research to identify "abnormal" asymmetry, fifteen of which utilised a threshold between 10-15%, yet this threshold was not always supported by appropriate evidence. Asymmetry scores ranged between and within populations from approximate symmetry to asymmetries larger than 15%. When reporting the effects of strength asymmetries, increased injury risk and detriments to performance were often associated with larger asymmetry, however the evidence was inconsistent. Limitations of asymmetry indices should be recognised, particularly those that require selection of a reference limb. Failure to reference the origin of the evidence for an asymmetry threshold reinforces doubt over the use of arbitrary thresholds, such as 10-15%. Therefore, an individual approach to defining asymmetry may be necessary to refine robust calculation methods and to establish appropriate thresholds across various samples and methodologies that enable appropriate conclusions to be drawn.

Early postoperative practices following anterior cruciate ligament reconstruction in France

INTRODUCTION

The early postoperative period after anterior cruciate ligament reconstruction (ACL) is critical for optimal functional recovery. Despite an abundance of literature, there is no consensus regarding good practices. This period is often under-considered by orthopedic surgeons. The aim of this study was to identify early postoperative practices after ACL reconstruction in France.

HYPOTHESIS

The hypothesis was that there was a discrepancy between validated data in the literature and the current practices of orthopedic surgeons in France.

MATERIAL AND METHODS

In 2019, a questionnaire was sent to all the members of the French Arthroscopy Society to investigate their postoperative practices after ACL reconstruction. Two hundred sixty-nine members responded. Surgeons were divided into two groups of experienced (n=137) and less experienced (n=132) surgeons, according to the number of ACL reconstructions performed per year (<or≥50/year). Outpatient management, effusion prevention measures, and rehabilitation instructions and goals were collected. Overall responses were analyzed after multiple linear logistic regression and the responses of the two groups were compared.

RESULTS

ACL reconstruction was performed as an outpatient procedure in 72.9% of cases. This rate increased with surgical experience (p=0.009×10^-3). Among measures to prevent effusion, cryotherapy was recommended in 97.8% of cases. The experienced group more often used compressive cryotherapy devices (p=0.004). Rehabilitation was started immediately in 75.5% of cases, with as main objective recovery of full extension (89.6%). Weight-bearing was allowed in 98.5% of cases and a brace was prescribed in 69.9% of cases. In the experienced group, braces were less frequent (p=0.02) and self-rehabilitation was preferred (p=0.0006).

CONCLUSION

Early postoperative practices after ACL reconstruction in France are related to surgical experience. The greater the surgical experience, the greater the role of joint effusion prevention and self-rehabilitation. Despite recommendations in the literature, a quarter of the French orthopedic surgeons who responded to this survey did not perform this procedure on an outpatient basis and more than two-thirds prescribed braces.

LEVEL OF EVIDENCE

IV.

Kinetic measurement system use in individuals following anterior cruciate ligament reconstruction: a scoping review of methodological approaches

Purpose

Our primary objectives were to (1) describe current approaches for kinetic measurements in individuals following anterior cruciate ligament reconstruction (ACLR) and (2) suggest considerations for methodological reporting. Secondarily, we explored the relationship between kinetic measurement system findings and patient-reported outcome measures (PROMs).

Methods

We followed the PRISMA extension for scoping reviews and Arksey and O’Malley’s 6-stage framework. Seven electronic databases were systematically searched from inception to June 2020. Original research papers reporting parameters measured by kinetic measurement systems in individuals at least 6-months post primary ACLR were included.

Results

In 158 included studies, 7 kinetic measurement systems (force plates, balance platforms, pressure mats, force-measuring treadmills, Wii balance boards, contact mats connected to jump systems, and single-sensor insoles) were identified 4 main movement categories (landing/jumping, standing balance, gait, and other functional tasks). Substantial heterogeneity was noted in the methods used and outcomes assessed; this review highlighted common methodological reporting gaps for essential items related to movement tasks, kinetic system features, justification and operationalization of selected outcome parameters, participant preparation, and testing protocol details. Accordingly, we suggest considerations for methodological reporting in future research. Only 6 studies included PROMs with inconsistency in the reported parameters and/or PROMs.

Conclusion

Clear and accurate reporting is vital to facilitate cross-study comparisons and improve the clinical application of kinetic measurement systems after ACLR. Based on the current evidence, we suggest methodological considerations to guide reporting in future research. Future studies are needed to examine potential correlations between kinetic parameters and PROMs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40634-021-00397-0.

Functional Bracing Following Anterior Cruciate Ligament Reconstruction: A Critical Analysis Review

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Anterior cruciate ligament (ACL) injuries remain common among athletes; these injuries require reconstruction to restore stability and enable successful return to sport.

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The role of postoperative dynamic knee bracing following ACL reconstruction in protecting graft integrity and promoting return to sport remains largely unknown.

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Limited biomechanical studies on functional bracing have reported decreased strain across the ACL with increasing anterior shear loading.

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Investigations evaluating functional brace use in clinical studies have not yet demonstrated consistent improvement in clinical outcomes, reduced graft retear rates, or improved return-to-sport rates in sports other than skiing.

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Additional investigation examining athletes of various ages participating in different sporting activities is necessary to better understand the role of functional bracing following ACL reconstruction.

Reduction of Risk Factors for ACL Re-injuries using an Innovative Biofeedback Approach: Rationale and Design

Nearly 1 in 60 adolescent athletes will suffer anterior cruciate ligament (ACL) injuries with 90% of these athletes electing to undergo an ACL reconstruction (ACLR) at an estimated annual cost of $3 billion. While ACLR and subsequent rehabilitation allow these athletes to return to sports, they have a 15-fold increased risk of second ACL injuries. The modification of post-operative rehabilitation to improve movement and loading symmetry using visual and tactile biofeedback could decrease the risk factors for sustaining a second ACL injury. Participants included 40 adolescent ACLR patients who were intending to return to full sport participation. This preliminary randomized controlled trial (RCT) examined the changes in knee extension moment symmetry, a known risk factor for second ACL injuries, during landing from a stop-jump task between the following time-points: pre-intervention, immediate post-intervention, and subsequent follow-up 6-weeks post-intervention. Participants met twice per week for six-weeks (12-session). The intervention included bilateral squat biofeedback (visual and tactile); the attention control group attended weekly educational sessions. This RCT enrolled and randomize 40 participants over a two-and-a-half-year period. All participants were greater than 4.5 months post-op from a primary, unilateral ACLR and were released to participate by their treating physician. The findings from this pilot biofeedback RCT will provide critical effect size estimates for use in subsequent larger clinical trials.

Physical Performance Improves With Time and a Functional Knee Brace in Athletes After ACL Reconstruction

Background:

Athletes who return to sport (RTS) after anterior cruciate ligament reconstruction (ACLR) often have reduced physical performance and a high reinjury rate. Additionally, it is currently unclear how physical performance measures can change during the RTS transition and with the use of a functional knee brace.

Purpose/Hypothesis:

The purpose of this study was to examine the effects of time since surgery (at RTS and 3 months after RTS) and of wearing a brace on physical performance in patients who have undergone ACLR. We hypothesized that physical performance measures would improve with time and would not be affected by brace condition.

Study Design:

Controlled laboratory study.

Methods:

A total of 28 patients who underwent ACLR (9 males, 19 females) completed physical performance testing both after being released for RTS and 3 months later. Physical performance tests included the modified agility t test (MAT) and vertical jump height, which were completed with and without a knee brace. A repeated-measures analysis of variance determined the effect of time and bracing on performance measures.

Results:

The impact of the knee brace was different at the 2 time points for the MAT side shuffle (P = .047). Wearing a functional knee brace did not affect any other physical performance measure. MAT times improved for total time (P < .001) and backpedal (P < .001), and vertical jump height increased (P = .002) in the 3 months after RTS.

Conclusion:

The present study showed that physical performance measures of agility and vertical jump height improved in the first 3 months after RTS. This study also showed that wearing a knee brace did not hinder physical performance.

Clinical Relevance:

Wearing a functional knee brace does not affect physical performance, and therefore a brace could be worn during the RTS transition without concern. Additionally, physical performance measures may still improve 3 months past traditional RTS, therefore justifying delayed RTS.