Functional performance 6 months after ACL reconstruction can predict return to participation in the same preinjury activity level 12 and 24 months after surgery

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

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

Return to the Pre-Injury Level of Sport after Anterior Cruciate Ligament Reconstruction: A Practical Review with Medical Recommendations

Returning to sport after anterior cruciate ligament reconstruction (ACLR) can be a challenging and complex process for the athlete, with the rate of return to the pre-injury level of sport observed to be less than athlete expectations. Of the athletes that do return to sport (RTS), knee re-injury rates remain high, and multiple studies have observed impaired athletic performance upon RTS after ACLR as well as reduced playing time, productivity, and career lengths. To mitigate re-injury and improve RTS outcomes, multiple RTS after ACLR consensus statements/clinical practice guidelines have recommended objective RTS testing criteria to be met prior to medical clearance for unrestricted sports participation. While the achievement of RTS testing criteria can improve RTS rates after ACLR, current criteria do not appear valid for predicting safe RTS. Therefore, there is a need to review the various factors related to the successful return to the pre-injury level of sport after ACLR, clarify the utility of objective performance testing and RTS criteria, further discuss safe RTS decision-making as well as present strategies to reduce the risk of ACL injury/re-injury upon RTS. This article provides a practical review of the current RTS after ACLR literature, as well as makes medical recommendations for rehabilitation and RTS decision-making after ACLR.

Factors Associated with Return to Sport After Anterior Cruciate Ligament Reconstruction: A Focus on Athletes Who Desire Preinjury Level of Sport

INTRODUCTION

 In most previous studies investigating return to preinjury level of sport (RTPS) after anterior cruciate ligament reconstruction (ACLR), whether patients continue aiming for RTPS not only before but also after ACLR was unclear because environmental and social factors were not considered. Herein, we aimed to evaluate factors associated with RTPS among athletes who desired to achieve RTPS even after ACLR, excluding patients who no longer desire this goal owing to environmental and social factors.

METHODS

 Ninety-two patients who underwent primary double-bundle ACLR with a minimum 2-year follow-up and desired to achieve RTPS before surgery were retrospectively enrolled. Twelve (13%) patients who no longer desired to achieve RTPS after ACLR owing to environmental and social factors were excluded. Sixty-nine patients were included in the final cohort. At the final follow-up, the patients were split into two groups: those who achieved (R group) or did not achieve (N group) RTPS based on patient self-assessment. The Knee Injury and Osteoarthritis Outcome Score (KOOS) and Lysholm scores were also determined. The anterior tibial translation in the Lachman test and acceleration and external rotational angular velocity (ERAV) in the pivot shift test were measured at the hardware removal operation.

RESULTS

 Significant differences were observed for preinjury level of sports between the groups (p < 0.05). The rate of RTPS in competitive athletes was lower than that in recreational athletes (20/46: 43% vs. 16/22: 73%; p =.037). Lysholm score, KOOS symptom, pain, and quality of life showed higher values in the R group than in the N group (p < 0.050). Acceleration was significantly lower in the R group than in the N group (p = 0.028).

CONCLUSION

 Competitive level of sports is a risk factor for failure to achieve RTPS. The postoperative functional outcomes in the group that achieved RTPS showed more favorable results. These results provide important information to enable the surgeons to consider the appropriate surgical plan for competitive athletes who desire to achieve RTPS after ACLR.

Bone-patellar tendon-bone autograft is associated with a higher rate of return to preinjury levels of performance in high-level athletes than anterior cruciate ligament reconstruction using hamstring autograft

PURPOSE

Return to preinjury levels of performance (RTP) is the main goal after anterior cruciate ligament reconstruction (ACL-R) for athletes when ACL graft rupture is a career-threatening event. The purpose of this study was to elucidate the associated factors for RTP and subsequent ACL injury after ACL-R using bone-patellar tendon-bone (BPTB) or hamstring (HT) autograft in high-level athletes with a minimum postoperative follow-up of 24 months.

METHODS

This retrospective study included 157 patients who had preinjury Tegner activity level of 9 and underwent primary ACL-R using BPTB (average age, 16.9 years; 35 males and 36 females) or HT (average age, 17.2 years; 49 males and 37 females). The mean follow-ups were 33.6 months in BPTB and 44.5 months in HT, respectively. The data were obtained based on routine clinical follow-ups and telephone interviews performed by the surgeon. Multivariate logistic regression analysis was conducted to determine the association of patient variables with RTP and subsequent ACL injury.

RESULTS

Ninety-nine patients (63.1%) were able to RTP. The rate of RTP in BPTB (74.6%) was significantly higher than that of HT (53.5%) (p < 0.05). The overall average timing of RTP after ACL-R was 10.0 months while that was significantly earlier in BPTB (9.7 months) than in HT (10.5 months) (p < 0.05). Twenty-three (14.6%) and 21 patients (13.4%) had ACL graft ruptures and ACL injuries in the contralateral knees, respectively. Multivariate analyses showed that BPTB (odds ratio [OR], 2.590; 95% confidence interval [CI], 1.300-5.160; p = 0.007) was associated with a higher potential for RTP after ACL-R. The incidence of ACL graft rupture after ACL-R decreased with BPTB (OR, 0.861; 95% CI, 0.770-0.962; p = 0.009).

CONCLUSIONS

The use of BPTB autograft was associated with a higher rate of RTP and a lower incidence of ACL graft rupture compared to ACL-R using HT autograft.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Are lower limb symmetry and self-reported symptoms associated with functional and neuromuscular outcomes in Brazilian adults with anterior cruciate ligament reconstruction? A cross-sectional study

INTRODUCTION

After anterior cruciate ligament (ACL) reconstruction, determining readiness to return to participation is challenging. The understanding of which neuromuscular performance parameters are associated with limb symmetry and self-reported symptoms may be useful to improve monitoring the rehabilitation towards adequate decision-making to return.

OBJECTIVES

To compare the ACL-operated and injury-free lower limbs regarding functional performance; and to investigate whether lower limb strength and functional performance are associated with self-reported symptoms and functional lower limb symmetry.

METHOD

Thirty-four participants were included. Functional performance was assessed by using the Y-Balance test, Single-leg Hop, and Functional Movement Screen. An isokinetic dynamometer was used to evaluate the strength levels in open and closed kinetic chains. The functional lower limb symmetry was calculated considering the single-leg hop test results for each lower limb.

RESULTS

There were no differences in dynamic balance (Y-Balance) between the operated and injury-free limbs. The operated limb presented a worst performance in the single-leg hop. Self-reported symptoms prevalence and lower limb symmetry were associated with knee extension strength and functional performance (Y-Balance).

CONCLUSION

Individuals submitted to ACL-reconstruction presented worse functional performance in the operated limb compared to the injury-free limb. Both knee strength and dynamic balance were associated with limb symmetry and self-reported symptoms.

Limb asymmetries persist 6 months after anterior cruciate ligament reconstruction according to the results of a jump test battery

Objectives

Test batteries used to assess a patient's return-to-sports (RTS) following anterior cruciate ligament reconstruction (ACLR) are currently undergoing continual development, although no consensus exist on tests to be administered to athletes before allowing return to play. A simple standardized jump test battery was developed to objectively evaluate knee function following ACLR, thereby aiding in RTS decision-making.

Methods

Thirty-three patients who underwent ACLR were prospectively assessed pre-operatively, 6, and 12 months after surgery. Knee function was assessed using a device for optical detection using a test battery consisting of three jump tests: monopodalic countermovement jump (CMJ), drop jump, and monopodalic side-hop. Limb symmetry index (LSI) was reported for all tests at all time points. LSI ≥90% was defined as RTS criteria.

Results

At 12-month evaluation, mean LSI significantly improved compared to 6-month follow up (p < 0.01), and also compared to baseline (p < 0.01), reporting a mean value of 92.6% for CMJ, 90.6 for drop jump and 96.9% for side hop test. Most patients fulfilled the RTS criteria 12 months after surgery (LSI ≥90%). The percentages of patients demonstrating LSI ≥90% at 6 months was 7/33 (21.2%) for CMJ, 12/33 (36.4%) for drop jump, and 11/33 (33.3%) for side-hop test. One year after surgery, percentages grew up to 66.6% (22/33), 63.6% (21/33), and 81.8% (27/33) respectively.

Conclusion

Six months after ACLR, knee functional performance was unsatisfactory in most patients, whereas a significantly higher percentage of patients met RTS criteria 1 year after surgery. The results of the jump test battery proposed in this study support the idea that timing for resumption of cutting and pivoting sports should be delayed later than 6 months, as still limb asymmetries persist at this time point.

The optimal window for reconstruction of the anterior cruciate ligament (ACL) with respect to quadriceps atrophies lies within 21 to 100 days

PURPOSE

The study's objective was to determine the optimal window for anterior cruciate ligament (ACL) reconstruction with respect to quadriceps atrophies and clinical outcome.

METHODS

For this retrospective, comparative study, 115 patients aged under 35 were included, who received an ACL reconstruction between 2011 and 2016. They were divided into four groups, depending on the time to surgery, to determine the optimal window for reconstruction: (group 1: ≤21 d, group 2: <21d-56d≥, group 3: >56d-100d≥, group 4: >100d). Follow-up was performed one month postoperatively, after a mean of 4.9 (±5.3) months, and after a mean of 3.5 (±1.4) years. Primary endpoints included quadriceps muscle status, range of motion (ROM), pain, swelling, the International Knee Documentation Committee Subjective Knee Form (IKDC), the Lysholm-Score, the Knee Injury and Osteoarthritis Outcome Score (KOOS), and the Tegner-Activity-Scale (TAS).

RESULTS

Significantly more quadriceps atrophies were observed in group 1 and group 4, representing reconstructions earlier than 21 and later than 100 days (29% and 41% vs. 9%; p = 0.032). The measurements of knee extension (p = 0.082) and ROM (p = 0.123) were comparable in all groups. Group 1 showed the least pain (0% vs. 15%; p = 0.285) and swelling (0% vs. 23%; p = 0.077) compared to all other groups one month postoperatively. A comparison of postoperative clinical scores revealed no significant differences, with group 1 exhibiting the lowest TAS levels.

CONCLUSION

In patients who underwent ACL reconstruction within three weeks or after more than 100 days, a significantly higher incidence of quadriceps atrophy was observed, possibly attributable to the initial inflammatory phase or the delayed reconstruction affecting quadriceps function. However, this impairment may not be observable in elite athletes who undergo reconstruction within hours of the injury.

Follow-up Treatment after Cartilage Therapy of the Knee Joint - a Recommendation of the DGOU Clinical Tissue Regeneration Working Group

The first follow-up treatment recommendation from the DGOU's Clinical Tissue Regeneration working group dates back to 2012. New scientific evidence and changed framework conditions made it necessary to update the follow-up treatment recommendations after cartilage therapy.As part of a multi-stage member survey, a consensus was reached which, together with the scientific evidence, provides the basis for the present follow-up treatment recommendation.The decisive criterion for follow-up treatment is still the defect localisation. A distinction is made between femorotibial and patellofemoral defects. In addition, further criteria regarding cartilage defects are now also taken into account (stable cartilage edge, location outside the main stress zone) and the different methods of cartilage therapy (e. g. osteochondral transplantation, minced cartilage) are discussed.The present updated recommendation includes different aspects of follow-up treatment, starting with early perioperative management through to sports clearance and resumption of contact sports after cartilage therapy has taken place.

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.

The Effect of Staged Versus Usual Care Physiotherapy on Knee Function Following Anterior Cruciate Ligament Reconstruction

CONTEXT

The long duration and high cost of anterior cruciate ligament reconstruction (ACLR) rehabilitation can pose barriers to completing rehabilitation, the latter stages of which progress to demanding sport-specific exercises critical for a safe return to sport. A staged approach shifting in-person physiotherapy sessions to later months of recovery may ensure patients undergo the sport-specific portion of ACLR rehabilitation. Design/Objective: To compare postoperative outcomes of knee function in patients participating in a staged ACLR physiotherapy program to patients participating in usual care physiotherapy through a randomized controlled trial.

METHODS

One hundred sixty-two patients were randomized to participate in staged (n = 80) or usual care physiotherapy (n = 82) following ACLR and assessed preoperatively and postoperatively at 2 weeks, 6 weeks, 3 months, and 6 months. The staged group completed the ACLR rehabilitation protocol at home for the first 3 months, followed by usual care in-person sessions. The usual care group completed in-person sessions for their entire rehabilitation. Outcome measures included the Lower Extremity Functional Scale, International Knee Documentation Committee Questionnaire, pain, range of motion, strength, and hop testing.

RESULTS

There were no statistically significant between-group differences in measures of knee function at 6 months postoperative. Patients in the usual care group reported significantly higher International Knee Documentation Committee scores at 3 months postoperative (mean difference = 5.8; 95% confidence interval,  1.3 to 10.4; P = .01).

CONCLUSION

A staged approach to ACLR rehabilitation does not appear to impede knee function at 6 months postoperative but may result in worse patient reported outcomes at early follow-ups.

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.

Monitoring External Workload With Wearable Technology After Anterior Cruciate Ligament Reconstruction: A Scoping Review

Background

Current sports medicine and rehabilitation trends indicate an increasing use of wearable technology. The ability of these devices to collect, transmit, and process physiological, biomechanical, bioenergy, and environmental data may aid in anterior cruciate ligament reconstruction (ACLR) workload monitoring and return-to-sport decision-making. In addition, their ease of use allows assessments to occur outside the clinical or laboratory settings and across a broader timeline.

Purpose

To (1) determine how wearable technology can assess external workload deficits between limbs (involved and uninvolved) and between groups (healthy controls vs patients with ACLR) during physical activity (PA) or sport and (2) describe the types of sensors, sensor specifications, assessment protocols, outcomes of interest, and participant characteristics from the included studies.

Study Design

Scoping review; Level of evidence, 4.

Methods

In February 2023, a systematic search was performed in the MEDLINE, EMBASE, CINAHL, SPORTDiscus, Scopus, IEEE Xplore, Compendex, and ProQuest Dissertations and Theses Global databases. Eligible studies included assessments of PA or sports workloads via wearable technology after ACLR.

Results

Twenty articles met eligibility criteria and were included. The primary activity assessed was activities of daily living, although rehabilitation, training, and competition were also represented. Accelerometers, global positioning system units, pedometers, and pressure sensor insoles were worn to collect external workload data, which was quantified as kinetic, kinematic, and temporospatial data. Daily steps (count) and moderate to vigorous PA (min/day or week) were the most common units of measurement. A limited number of studies included outcomes related to between-limb asymmetries.

Conclusion

The findings of this scoping review highlight the versatility of wearable technologies to collect patients' kinetic, kinematic, and temporospatial data and assess external workload outcomes after ACLR. In addition, some wearable technologies identified deficits in workload compared with healthy controls and between reconstructed and unaffected limbs.

Differences in psychological readiness for return to sport after anterior cruciate ligament injury is evident in thigh musculature motor unit characteristics

Background

Following anterior cruciate ligament (ACL) injury, many athletes that undergo surgery and 6-9 months of rehabilitation struggle to return to sport. Evidence suggests that psychological factors contribute to this failure to return-to-sport.

Objective

Determine the motor control relationship between thigh musculature motor unit characteristics and psychological readiness to return to sport between ACL-injured and healthy controls.

Study design

A longitudinal cohort study.

Methods

Athletes longitudinally completed the ACL Return to Sport after Injury (ACL-RSI) survey and isometric strength measures with a measurement of electromyography (EMG) of the vastus lateralis, vastus medialis, biceps femoris, and semitendinosus. A score cut-off of 61 on the ACL-RSI was used to divide ACL-injured groups. EMG was decomposed to provide each identified motor unit's characteristics (amplitude, average firing rate, etc).

Results

Data demonstrated increased average firing rate for hamstrings (p<0.001), decreased average firing rate for vastus lateralis (p<0.001) and decreased motor unit size for both the quadriceps and hamstrings at return-to-sport post-ACL reconstruction compared with sex-matched and age-matched healthy controls (p<0.001). Furthermore, there were marked differences in disparate ACL-RSI scores between ACL-injured athletes.

Conclusions

At return to sport, ACL-injured athletes have major alterations of thigh musculature motor control, with smaller motor units used by those with low ACL-RSI scores. This study uniquely demonstrates objective thigh muscle motor unit characteristics that coincide with subjective reports of psychological readiness. This information will be important to address psychomotor complexes of injury for future rehabilitation protocols.

Hip Abductor and External Rotator Strengths Correlate With Hop Symmetry in Men Athletes 2 Years After Anterior Cruciate Ligament Reconstruction

CONTEXT

Hip muscle strength and hop performance limb symmetries after anterior cruciate ligament reconstruction (ACLR) are not well studied. This study aimed to determine the differences in hip abductors' (ABD) and external rotators' (ER) muscle strength measures between limbs, and the relationship between hip ABD and ER muscle strengths and hop performance limb symmetry indices (LSIs) 2 years after ACLR.

DESIGN

Cross-sectional study.

METHODS

Forty (level I/II) men athletes 2 years after unilateral ACLR completed 4 single-legged hop tests and involved hip ABD and ER strength testing (maximum voluntary isometric contraction [MVIC]; isokinetic peak torque [PKTQ] at 60°, 180°, and 300°/s; and isotonic peak velocity at 75% of their MVICs). Muscle strength measures were normalized to body mass, and hop performances were reported as LSIs. Paired t test was used to determine strength differences between limbs, and the Pearson correlation coefficient was used to assess the relationship between involved hip muscle strength measures and hop performance LSIs.

RESULTS

Hip ER-MVIC (involved: 60.26 [12.01], uninvolved: 63.68 [13.17] N·m/kg) and ER eccentric PKTQ at 60°/s (involved: 32.59 [9.28]; uninvolved: 35.73 [10.50] N·m/kg) were significantly different between limbs (P ≤ .018). Single-hop LSI correlated with hip ER-PKTQ at 180°/s (r = .354) and 300°/s (r = .324, P ≤ .041), while triple-hop LSI correlated with hip ER-MVIC (r = .320), concentric ER-PKTQ at 180°/s (r = .355), eccentric ER-PKTQ at 60°/s (r = .314), and hip ABD-PKTQ at 60°/s (r = .364) and 300°/s (r = .336, P ≤ .049).

CONCLUSIONS

Men athletes demonstrated symmetrical hop performance and hip muscle strengths, except for ER hip's MVIC and isokinetic eccentric peak torque at 60°/s 2 years after ACLR. Hop performance LSIs had a few, yet positive moderate relationships with involved hip ABDs and ER strength measures. This may indicate that hip ABD and ER muscle strength measures contribute to athletes' hop performances 2 years after ACLR. Post-ACLR rehabilitation programs might incorporate hip muscle strengthening training to improve athletes' functional performances.

Return to Sport After Anterior Cruciate Ligament Reconstruction Requires Evaluation of >2 Functional Tests, Psychological Readiness, Quadriceps/Hamstring Strength, and Time After Surgery of 8 Months

PURPOSE

The purpose of this study was to examine the factors commonly used to determine readiness for return to sport (RTS) in the ACL reconstruction (ACL-R) patient population and assess which were most influential to successfully returning to sport and avoiding re-tear.

METHODS

The PUBMED, EMBASE and Cochrane Library databases were queried for studies related to RTS in ACL-R. Inclusion and exclusion criteria were applied to identify studies with greater than 1-year outcomes detailing the rate of return and re-tear given a described RTS protocol. Data of interest were extracted, and studies were stratified based on level of evidence and selected study features. Meta-analysis or subjective synthesis of appropriate studies was used to assess more than 25 potentially significant variables effecting RTS and re-tear.

RESULTS

After initial search of 1503 studies, 47 articles were selected for inclusion in the final data analysis, including a total of 1432 patients (31.4% female, 68.6% male). A meta-analysis of re-tear rate for included Level of Evidence 1 studies was calculated to be 2.8%. Subgroups including protocols containing a strict time until RTS, strength testing, and ≥2 dynamic tests demonstrated decreased RTS and re-tear heterogeneity from the larger group. Time to RTS, strength testing, dynamic functional testing, and knee stability were also found to be among the most prevalent reported criteria in RTS protocol studies.

CONCLUSIONS

This study suggests a multifactorial clinical algorithm for successful evaluation of RTS. The "critical criteria" recommended by the authors to be part of the postoperative RTS criteria include time since surgery of 8 months, use of >2 functional tests, psychological readiness testing, and quadriceps/hamstring strength testing in addition to the modifying patient factors of age and female gender.

LEVEL OF EVIDENCE

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

Patient-Reported Measures Associated with the Return to Pre-Injury Levels of Sport 2 Years after Anterior Cruciate Ligament Reconstruction

The International Knee Documentation Committee Subjective Knee Form (IKDC2000) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) are knee-specific measures. However, their association with a return to sports after anterior cruciate ligament reconstruction (ACLR) is unknown. This study aimed to investigate the association between the IKDC2000 and the KOOS subscales and the return to the same pre-injury level of sport two years after ACLR. Forty athletes that were two years post-ACLR participated in this study. Athletes provided demographic information, filled out the IKDC2000 and KOOS subscales, and indicated whether they returned to any sport and whether they returned to the same pre-injury level (same duration, intensity, and frequency). In this study, 29 (72.5%) athletes returned to play any sport and eight (20%) returned to the same pre-injury level. The IKDC2000 (r: 0.306, p = 0.041) and KOOS quality of life (KOOS-QOL) (r: 0.294, p = 0.046) significantly correlated with the return to any sport, but it was age (r: -0.364, p = 0.021), BMI (r: -0.342, p = 0.031), IKDC2000 (r: 0.447, p = 0.002), KOOS-pain (r: 0.317, p = 0.046), KOOS sport and recreation function (KOOS-sport/rec)(r: 0.371, p = 0.018), and KOOS QOL (r: 0.580, p > 0.001) that significantly correlated with a return to the same pre-injury level. High KOOS-QOL and IKDC2000 scores were associated with returning to any sport, and high KOOS-pain, KOOS-sport/rec, KOOS-QOL, and IKDC2000 scores were all associated with returning to the same pre-injury level of sport.

Association between knee function and kinesiophobia 6 months after anterior cruciate ligament reconstruction

[Purpose] Kinesiophobia after anterior cruciate ligament reconstruction has been identified as an inhibitor of return to sports. This study aimed to clarify the relationship between kinesiophobia and knee function 6 months after anterior cruciate ligament reconstruction when the patient intends to return to sports. [Participants and Methods] A total of 66 patients who underwent primary anterior cruciate ligament reconstruction (mean age 17.3 ± 2.6 years, 17 males and 49 females, Tegner activity score ≥7) were included in the study. The 11-item version of Tampa scale of kinesiophobia was used to evaluate kinesiophobia 6 months postoperatively. Knee function was evaluated with knee extension muscle strength, tibial anterior displacement, heel buttock distance, heel height difference, anterior knee pain score, and single-leg hop test. The relationship between Tampa scale of kinesiophobia, patient characteristics, and knee function was investigated. [Results] A low Anterior knee pain score and low single-leg hop test, male gender, and age were significant factors associated with kinesiophobia. [Conclusion] Kinesiophobia was associated with a low anterior knee pain score and low single-leg hop test 6 months after anterior cruciate ligament reconstruction. Patients with a low single-leg hop test score or severe pain may need rehabilitation to reduce kinesiophobia.

Translation, cross-cultural adaptation and validation of the Italian version of the knee outcome survey - activities of daily living scale

PURPOSE

The Knee Outcome Survey - Activities of Daily Living Scale (KOS-ADLS) is a joint-specific questionnaire measuring symptoms and functional limitations experienced by individuals with painful knee disorders. The original version of the KOS-ADLS has been shown to be reliable, valid and responsive to change. The purpose of this study was to perform a translation and cross-cultural adaptation of the KOS-ADLS into Italian and to assess its reliability and validity.

METHODS

In accordance with standard procedures, the original version of the KOS-ADLS was translated and cross-culturally adapted into Italian (KOS-ADLS-I). Then, the KOS-ADLS-I was administered to 150 patients with knee disorders. A subsample of patients compiled the KOS-ADLS-I again after five/seven days later to evaluate test-retest reliability. Symptoms and function-oriented questionnaires were also completed to evaluate construct validity. Structural validity (Explanatory Factor Analysis [EFA]), internal consistency (Cronbach's alpha), test-retest reliability (Intraclass Correlation Coefficient [ICC]), measurement error (Standard Error of the Measurement [SEM], Minimal Detectable Change [MDC]), and construct validity (hypothesis testing) were assessed.

RESULTS

The cross-cultural adaptation procedure revealed no major problems. EFA revealed a unidimensional structure. Internal consistency was high (Cronbach's alpha = 0.976) and the test-retest reliability was excellent (ICC = 0.990, 95%CI: 0.980-0.995) with low measurement error (SEM = 2.6 points; MDC = 7.1 points). The construct validity resulted to be satisfactory, as 100% a-priori hypothesis were met.

CONCLUSIONS

The KOS-ADLS-I is a reliable and valid questionnaire for the assessment of symptoms and functional limitations in individuals with musculoskeletal knee disorders and it can be used in clinical practice and research.

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

OBJECTIVE

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

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

Six databases searched up to June 2021.

ELIGIBILITY CRITERIA

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

RESULTS

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

CONCLUSION

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

PROSPERO REGISTRATION NUMBER

CRD42018092197.

Academy of Orthopaedic Surgeons Clinical Practice Guideline Summary: Management of Anterior Cruciate Ligament Injuries

Management of Anterior Cruciate Ligament Injuries: Evidence-based Clinical Practice Guideline is based on a systematic review of published studies for the treatment of anterior cruciate ligament injurie in both skeletally mature and immature patients. This guideline contains eight recommendations and seven options to assist orthopaedic surgeons and all qualified physicians managing patients with ACL injuries based on the best current available evidence. It is also intended to serve as an information resource for professional healthcare practitioners and developers of practice guidelines and recommendations. In addition to providing pragmatic practice recommendations, this guideline also highlights gaps in the literature and informs areas for future research and quality measure development.

Morphometric risk factors effects on anterior cruciate ligament injury

OBJECTIVES

This study aims to compare the morphometric differences between patients with and without an anterior cruciate ligament (ACL) injury and to investigate the anatomical risk factors associated with ACL injury.

PATIENTS AND METHODS

Between February 2020 and February 2022, a total of 100 patients (57 males, 43 females; mean age: 36.2±6.8 years; range, 18 to 45 years) who were operated for isolated non-contact ACL tear as the patient group and a total of 100 healthy individuals (58 males, 42 females; mean age: 35.0±6.9 years; range, 18 to 45 years) without an ACL tear as the control group were included. Magnetic resonance imaging scans of the knee joint were included in the study. Morphological variables of the ACL, distal femur, proximal tibia, and menisci were measured.

RESULTS

The mean ACL inclination angle and medial meniscus bone angle were 37.7±3.8 and 20.2±2.9 in the patient group and 48.1±3.3 and 25.0±2.9 in the control group. According to the results of multivariate analysis, those with small ACL inclination angle and medial meniscus bone angle were more likely to have ACL tear (odds ratio: 0.128, intraclass correlation coefficient: 0.038-0.430, p=0.001).

CONCLUSION

Small ACL inclination angle and medial meniscus bone angle can be a risk factor for ACL tear.

How limb dominance influences limb symmetry in ACL patients: effects on functional performance

BACKGROUND

Timing for return to sport (RTS) after anterior cruciate ligament (ACL) injury is paramount for the avoidance of a secondary injury. A common criterion in RTS decision-making is the limb symmetry index (LSI) which quantifies (a)symmetries between the affected and unaffected limb. Limb dominance is one of many factors that may contribute to the recovery of the LSI after ACL reconstruction. The purpose of this study was to examine how limb dominance affects the LSI of functional performance tasks nine months following ACL reconstruction (time of RTS).

METHODS

At time of return to sport, n = 100 patients (n = 48 injured the dominant limb, n = 52 injured the non-dominant limb, n = 34 female, n = 66 male) with ACL reconstruction surgery performed isokinetic strength measurements of the knee extensors and flexors, and drop jumps (DJ), single leg hop for distance (SHD) and 6 m timed hop (6MTH) testings.

RESULTS

The findings indicated that injury of the dominant leg led to significantly higher LSI values in maximal isokinetic knee extensor strength (p = 0.030). No significant differences were observed for maximal isokinetic knee flexor strength, DJ, SHD or 6MTH performance. Stratifying for sex revealed no significant differences. Simple regression analyses demonstrated that LSI in maximal knee extensor strength significantly predicted LSIs in DJ and SHD while explaining 14% and 18% of the respective variance.

CONCLUSIONS

Given that limb dominance affects the LSI of muscle strength suggests that a differentiated interpretation of the LSI with respect to limb dominance should be considered for a safe return to sport. Monoarticular knee extensor strength and multiarticular hop test performance are interrelated and thus can show asymmetries which are not maladaptive but established during years of habituation or training.

Reliability of wearable sensors-based parameters for the assessment of knee stability

Anterior cruciate ligament (ACL) rupture represents one of the most recurrent knee injuries in soccer players. To allow a safe return to sport after ACL reconstruction, standardised and reliable procedures/criteria are needed. In this context, wearable sensors are gaining momentum as they allow obtaining objective information during sport-specific and in-the-field tasks. This paper aims at proposing a sensor-based protocol for the assessment of knee stability and at quantifying its reliability. Seventeen soccer players performed a single leg squat and a cross over hop test. Each participant was equipped with two magnetic-inertial measurement units located on the tibia and foot. Parameters related to the knee stability were obtained from linear acceleration and angular velocity signals. The intraclass correlation coefficient (ICC) and minimum detectable change (MDC) were calculated to evaluate each parameter reliability. The ICC ranged from 0.29 to 0.84 according to the considered parameter. Specifically, angular velocity-based parameters proved to be more reliable than acceleration-based counterparts, particularly in the cross over hop test (average ICC values of 0.46 and 0.63 for acceleration- and angular velocity-based parameters, respectively). An exception was represented, in the single leg squat, by parameters extracted from the acceleration trajectory on the tibial transverse plane (0.60≤ICC≤0.76), which can be considered as promising candidates for ACL injury risk assessment. Overall, greater ICC values were found for the dominant limb, with respect to the non-dominant one (average ICC: 0.64 and 0.53, respectively). Interestingly, this between-limb difference in variability was not always mirrored by LSI results. MDC values provide useful information in the perspective of applying the proposed protocol on athletes with ACL reconstruction. Thus, The outcome of this study sets the basis for the definition of reliable and objective criteria for return to sport clearance after ACL injury.

Primary surgery versus primary rehabilitation for treating anterior cruciate ligament injuries: a living systematic review and meta-analysis

OBJECTIVE

Compare the effectiveness of primarily surgical versus primarily rehabilitative management for anterior cruciate ligament (ACL) rupture.

DESIGN

Living systematic review and meta-analysis.

DATA SOURCES

Six databases, six trial registries and prior systematic reviews. Forward and backward citation tracking was employed.

ELIGIBILITY CRITERIA

Randomised controlled trials that compared primary reconstructive surgery and primary rehabilitative treatment with or without optional reconstructive surgery.

DATA SYNTHESIS

Bayesian random effects meta-analysis with empirical priors for the OR and standardised mean difference and 95% credible intervals (CrI), Cochrane RoB2, and the Grading of Recommendations Assessment, Development and Evaluation approach to judge the certainty of evidence.

RESULTS

Of 9514 records, 9 reports of three studies (320 participants in total) were included. No clinically important differences were observed at any follow-up for self-reported knee function (low to very low certainty of evidence). For radiological knee osteoarthritis, we found no effect at very low certainty of evidence in the long term (OR (95% CrI): 1.45 (0.30 to 5.17), two studies). Meniscal damage showed no effect at low certainty of evidence (OR: 0.85 (95% CI 0.45 to 1.62); one study) in the long term. No differences were observed between treatments for any other secondary outcome. Three ongoing randomised controlled trials were identified.

CONCLUSIONS

There is low to very low certainty of evidence that primary rehabilitation with optional surgical reconstruction results in similar outcome measures as early surgical reconstruction for ACL rupture. The findings challenge a historical paradigm that anatomic instability should be addressed with primary surgical stabilisation to provide optimal outcomes.

PROSPERO REGISTRATION NUMBER

CRD42021256537.

Cross-sectional study on relationships between physical function and psychological readiness to return to sport after anterior cruciate ligament reconstruction

BACKGROUND

Information about specific factors of physical function that contribute to psychological readiness is needed to plan rehabilitation for a return to sports. The purpose of this study was to identify specific physical functions related to the psychological readiness of patients aiming to return to sports 6 months after reconstruction. We hypothesized that the knee strength is a factor related to the Anterior Cruciate Ligament-Return to Sport after Injury scale (ACL-RSI) cutoff score for a return to sports.

METHODS

This was a cross-sectional study. Fifty-four patients who had undergone primary reconstruction using hamstring tendon participated in this study. Psychological readiness was measured using the ACL-RSI in patients at 6 months after reconstruction. To identify specific physical functions related to the ACL-RSI score, participants were divided into groups with ACL-RSI scores of ≥ 60 or < 60. Non-paired t-tests or the Mann-Whitney test were performed to analyze group differences in objective variables in physical function: (1) knee strength in both legs; (2) leg anterior reach distance on both sides; and (3) single-leg hop (SLH) distances in three directions for both legs.

RESULTS

Significant differences between groups were identified in knee flexion strength (60°/s) for the uninvolved limb, hamstring-to-quadriceps ratio (60°/s) for the uninvolved limb, knee flexion strength (180°/s) for the involved limb, limb symmetry index (LSI) of leg anterior reach distance, the ratio of the distance to the height of the patient and LSI of SLH distances in lateral and medial directions.

CONCLUSION

This study revealed that at 6 months after reconstruction, increased knee flexion strength (ratio of peak torque measured to body mass of the patient), hamstring-to-quadriceps ratio, leg anterior reach distance LSI, and lateral and medial SLH appear important to exceed the ACL-RSI cutoff for a return to sports. The present results may be useful for planning post-operative rehabilitation for long-term return to sports after reconstruction.

Association Between Meeting Return-to-Sport Criteria and Psychological Readiness to Return to Sport After Anterior Cruciate Ligament Reconstruction

Background:

The relationship between meeting return-to-sport criteria and psychological readiness after anterior cruciate ligament (ACL) reconstruction is unknown.

Purposes:

To examine (1) whether patients who met 1 of the criteria for return to sport had higher psychological readiness than those who did not meet any of the criteria and (2) if those who met more criteria had higher psychological readiness.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

This study included 144 patients who underwent unilateral ACL reconstruction. All patients had regularly participated in some sport activities before an ACL rupture. At 12 months postoperatively, each patient completed 3 knee function tests (isokinetic quadriceps strength, isokinetic hamstring strength, and single-leg hop distance) and 2 self-reported measures (International Knee Documentation Committee [IKDC] 2000 subjective form and ACL–Return to Sport after Injury [ACL-RSI] scale); the ACL-RSI scale was used to measure psychological readiness to return to sport. The 4 criteria for return to sport were a limb symmetry index (LSI) ≥90% for each of the 3 function tests in addition to an IKDC score ≥90. Multivariate regression analysis was used to determine the association between meeting the individual criteria and the ACL-RSI score. In addition, the patients were divided into 5 groups according to the number of criteria met, and the Kruskal-Wallis and Steel-Dwass tests were used to compare the ACL-RSI scores among the groups.

Results:

Overall, 23 patients (16.0%) met none of the criteria for return to sport, 27 (18.7%) met 1 of the criteria, 34 (23.6%) met 2 criteria, 35 (24.3%) met 3 criteria, and 25 (17.4%) met all 4 criteria. Meeting the criteria for the hamstring strength LSI (P = .002), single-leg hop distance LSI (P = .004), and IKDC subjective score (P < .001) was each associated with higher ACL-RSI scores. Significant differences in ACL-RSI scores were found between patients who met none versus 2, 3, and 4 of the return-to-sport criteria (P < .001 for all) and between patients who met 1 versus 4 criteria (P < .001).

Conclusion:

Meeting return-to-sport criteria was positively associated with psychological readiness, and the patients who met multiple criteria had higher psychological readiness.

Evidence for isokinetic and functional testing in return to sport decisions following ACL surgery

The rupture and reconstruction of the anterior cruciate ligament (ACL) of the knee are associated with an increased risk of functional instability, a reduction in sports performance, and a higher risk of future additional injuries. Competitive athletes who participate in sports that require pivoting, cutting, and jumping are at particularly high risk for ACL rupture. The return to sport progression continuum after surgery includes sports-specific rehabilitation, evaluation of strength and function, gradual participation in exercise training with progressively challenging activities in the field of play, participation in sports at a lower level, and finally a return to preinjury-level sports competition. This narrative review evaluates the evidence that supports the use of quadriceps and hamstrings isokinetic strength testing and sports-specific functional skills assessments to evaluate progress with rehabilitation after ACL surgery. Strength evaluations, hop tests, agility tests, and the limb symmetry index are described, as well as the associations of quadriceps and hamstrings muscle strength and functional test results with successful return to sports and the risk of ACL graft rupture and contralateral knee injuries. Suggestions for future research directions are presented including the importance of presurgery testing, standardization of test batteries, and comparison of test results with normative data.

Anterior Cruciate Ligament Reconstruction Recovery and Rehabilitation: A Systematic Review

BACKGROUND

The success of anterior cruciate ligament (ACL) reconstruction is influenced by effective rehabilitation. Previously published, comprehensive systematic reviews evaluating rehabilitation after ACL reconstruction have studied Level-I and II evidence published through 2012. Interval studies continue to evaluate the efficacy of various rehabilitative modalities.

METHODS

A total of 824 articles from 2012 to 2020 were identified using multiple search engines. Fifty Level-I or II studies met inclusion criteria and were evaluated using the Consolidated Standards of Reporting Trials (CONSORT) criteria and National Institutes of Health (NIH) Study Quality Assessment Tools.

RESULTS

Accelerated rehabilitation can be effective for patients with semitendinosus-gracilis grafts. Blood flow restriction (BFR) training with high-intensity exercise is not effective for ACL reconstruction recovery. Postoperative bracing does not offer any advantages or improve limb asymmetry. Cryotherapy is an effective analgesic when used perioperatively. The early introduction of open kinetic chain exercises may improve ACL reconstruction outcomes, and high-intensity plyometric exercise is not effective. Estimated pre-injury capacity (EPIC) levels may be more accurate than the Limb Symmetry Index (LSI) when using functional test results to predict reinjury rates, and hip external rotation strength may be the most accurate predictor of the hop test performance. Nerve blocks can provide postoperative analgesia with minimal complication risk. Neuromuscular electrical stimulation is effective when used independently and in combination with rehabilitative exercises. Psychological readiness should be evaluated both objectively and subjectively before allowing patients to safely return to sport. Electromyography biofeedback may help to regain muscular function, and whole-body vibration therapy can improve postural control. Supervised rehabilitation is more effective than unsupervised rehabilitation.

CONCLUSIONS

Various rehabilitative modalities following ACL reconstruction are effective in improving surgical outcomes and return-to-sport rates. Further evidence and improved study design are needed to further validate modalities including accelerated rehabilitation, BFR training, functional testing, and return-to-sport criteria.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Knee strength symmetry at 4 months is associated with criteria and rates of return to sport after anterior cruciate ligament reconstruction

BACKGROUND

Strength limb symmetry index (LSI) is a useful criterion to help in return-to-sport performance (RTP) after anterior cruciate ligament reconstruction (ACLR).

OBJECTIVES

We aimed to assess whether knee extensor and flexor LSI values at 4 months after ACLR are associated with those recommended at 8 months after ACLR for RTP (80%, 85% and 90%) and with successful RTP after 2 years.

METHODS

This was prospective cohort study of 113 participants who underwent primary ACLR. Personal factors such as demographic and sport information, injury and surgery characteristics were collected at 6 weeks after surgery. Isokinetic strength LSI (60°/s) was calculated at 4 months (LSI[4m]) and 8 months (LSI[8m]) for knee extensors (Q-LSI) and flexors (H-LSI). Participants were followed at 2 years after ACLR to determine their self-reported RTP. Multiple linear regression analysis was used to determine associations between personal factors and LSI at 4 and 8 months. Associations between passing the optimal cut-off thresholds and RTP were tested with chi-square tests and odds ratios (ORs) with effect sizes (ES).

RESULTS

Among the 113 participants (mean age 25.2 [SD 9.7] years; 42% females), extended tourniquet time and lower level of pre-injury sport were associated with lower Q-LSI[4m] and H-LSI[4m]. Bone-patellar tendon-bone graft was associated with lower Q-LSI[4m] and Q-LSI[8m], and older age was associated with lower Q-LSI[4m]. For knee extensors, Q-LSI[4m] >59% was associated with Q-LSI[8m] >80% (OR= 31.50, p <0.001, large ES) and increased odds of successful RTP (60% vs 31%, OR= 3.45, p= 0.003, medium ES). For knee flexors, H-LSI[4m] >72% was associated with H-LSI[8m] >90% (OR= 6.03, p <0.001, large ES) and increased odds of successful RTP (53% vs 23%, OR= 3.76, p= 0.013, small-to-medium ES).

CONCLUSIONS

After primary ACLR, 4-month post-operative strength symmetry was negatively associated with age, pre-injury sport and tourniquet time and bone-patellar tendon-bone graft. Four-month post-operative LSI was associated with 8-month post-operative LSI, and Q-LSI[4m] >59% or H-LSI[4m] >72% was associated with increased RTP rates after 2 years. CLINICALTRIALS.GOV: : NCT04071912.

Biomechanical Markers of Forward Hop-Landing After ACL-Reconstruction: A Pattern Recognition Approach

Biomechanical changes after anterior cruciate ligament reconstruction (ACLR) may be detrimental to long-term knee-joint health. We used pattern recognition to characterise biomechanical differences during the landing phase of a single-leg forward hop after ACLR. Experimental data from 66 individuals 12-24 months post-ACLR (28.2 ± 6.3 years) and 32 controls (25.2 ± 4.8 years old) were input into a musculoskeletal modelling pipeline to calculate joint angles, joint moments and muscle forces. These waveforms were transformed into principal components (features), and input into a pattern recognition pipeline, which found 10 main distinguishing features (and 8 associated features) between ACLR and control landing biomechanics at significance \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\alpha =0.05$$\end{document}α=0.05. Our process identified known biomechanical characteristics post-ACLR: smaller knee flexion angle; less knee extensor moment; lower vasti, rectus femoris and hamstrings forces. Importantly, we found more novel and less well-understood adaptations: smaller ankle plantar flexor moment; lower soleus forces; and altered patterns of knee rotation angle, hip rotator moment and knee abduction moment. Crucially, we identified, with high certainty, subtle aberrations indicating landing instability in the ACLR group for: knee flexion and internal rotation angles and moments; hip rotation angles and moments; and lumbar rotator and bending moments. Our findings may benefit rehabilitation and assessment for return-to-sport 12–24 months post-ACLR.

A Compound Hop Index for Assessing Soccer Players' Performance

Athletes regularly have to pass a series of tests, among which one of the most frequently used functional performance measures are single-leg hop tests. As the collected individual results of tests constitute a large amount of data, strategies to decrease the amount of data without reducing the number of performed tests are being searched for. Therefore, the study aimed to present an effective method to reduce the hop-test battery data to a single score, namely, the Compound Hop Index (CHI) in the example of a soccer team. A male, first-league soccer team performed a battery of commonly used single-leg hop tests, including single hop and triple hop for distance tests and the six-meter timed hop test. Gathered data, including Limb Symmetry Indexes of the three tests, normalized to body height for the single- and triple-hop-tests distance separately for right and left legs, and the time of the six-meter timed hop test separately for right and left legs were standardized to z-scores. Consecutively, the z-scores were averaged and formed CHI. The developed CHI represents a novel score derived from the average of z-scores that significantly reduces, clarifies, and organizes the hop performance-measures data.

Age, time from injury to surgery and hop performance after primary ACLR affect the risk of contralateral ACLR

PURPOSE

To evaluate factors affecting the risk of contralateral anterior cruciate ligament reconstruction (ACLR) within 5 years of primary ACLR.

METHODS

Primary ACLRs performed at Capio Artro Clinic, Stockholm, Sweden, during the period 2005-2014, were reviewed. The outcome of the study was the occurrence of contralateral ACLR within 5 years of primary ACLR. Univariable and multivariable logistic regression analyses were employed to identify preoperative [age, gender, body mass index (BMI), time from injury to surgery, pre-injury Tegner activity level], intraoperative [graft type, medial meniscus (MM) and lateral meniscus (LM) resection or repair, cartilage injury] and postoperative [limb symmetry index (LSI) for quadriceps and hamstring strength and single-leg-hop test performance at 6 months] risk factors for contralateral ACLR.

RESULTS

A total of 5393 patients who underwent primary ACLR were included. The incidence of contralateral ACLR within 5 years was 4.7%. Univariable analysis revealed that age ≥ 25 years, BMI ≥ 25 kg/m², time from injury to surgery ≥ 12 months and the presence of a cartilage injury reduced the odds, whereas female gender, pre-injury Tegner activity level ≥ 6, quadriceps and hamstring strength and a single-leg-hop test LSI of ≥ 90% increased the odds of contralateral ACLR. Multivariable analysis showed that the risk of contralateral ACLR was significantly affected only from age ≥ 25 years (OR 0.40; 95% CI 0.28-0.58; P < 0.001), time from injury to surgery ≥ 12 months (OR 0.48; 95% CI 0.30-0.75; P = 0.001) and a single-leg-hop test LSI of ≥ 90% (OR 1.56; 95% CI 1.04-2.34; P = 0.03).

CONCLUSION

Older age (≥ 25 years) and delayed primary ACLR (≥ 12 months) reduced the odds, whereas a symmetrical (LSI ≥ 90%) 6-month single-leg-hop test increased the odds of contralateral ACLR within 5 years of primary ACLR. Knowledge of the factors affecting the risk of contralateral ACLR is important when it comes to the appropriate counselling for primary ACLR. Patients should be advised regarding factors affecting the risk of contralateral ACLR.

LEVEL OF EVIDENCE

Level III.

Return to play testing following anterior cruciate reconstruction - A systematic review & meta-analysis

PURPOSE

The purpose of this study is to systematically review the evidence regarding return to sport evaluation following ACL reconstruction and evaluate the relationship between testing and secondary ACL injury.

METHODS

A systematic review of the literature with PubMed, Ovid MEDLINE, Cochrane Reviews, was performed on June, 2020 based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were included if they compared outcomes following passing and failing RTP testing subsequent to ACLR. Clinical outcomes were compared, with all statistical analysis performed using Review Manager Version 5.3. Correlation was calculated with Spearman testing.

RESULTS

Overall, 8 studies with 1224 patients were included in the analysis. Overall, 34.3% (420/1224) patients passed the RTP testing. Those who passed the RTP testing had a statistically significant 47% lower rate of ACL graft re-rupture compared to those who did not pass the RTP testing (p = 0.03). However, there was a slightly higher, albeit not statistically significant, rate of contralateral ACL rupture in those who passed the RTP testing compared to those who did not (p = 0.42). There was a strong positive correlation between a high rate of patients passing the ACL RTP testing in studies and ACL graft rupture rate in those who failed (0.80).

CONCLUSION

Passing RTP testing following ACLR results in a lower rate of ACL graft rupture, but not contralateral ACL injury. Further evaluation and standardization of RTP testing is necessary in order to increase reliability in identifying patients at risk for re-injury after ACLR.

LEVEL OF EVIDENCE

Level of Evidence III.

Anterolateral Ligament Reconstruction Does Not Delay Functional Recovery, Rehabilitation, and Return to Sport After Anterior Cruciate Ligament Reconstruction: A Matched-Pair Analysis From the SANTI (Scientific ACL Network International) Study Group

PURPOSE

To determine whether the addition of an anterolateral ligament reconstruction (ALLR) resulted in delayed functional recovery (based on the Knee Santy Athletic Return to Sport [K-STARTS] score) at 6 months after anterior cruciate ligament reconstruction (ACLR).

METHODS

A retrospective analysis of prospectively collected data from consecutive patients who underwent an ACLR between September 2017 and December 2020 was conducted. Patients who received an isolated hamstring autograft (isolated ACLR group) were propensity matched in a 1:1 ratio to patients who received a hamstring autograft ACLR combined with an ALLR (ACLR-ALLR group). Outcome measures included the Tegner Activity Scale and the K-STARTS test-a validated composite return-to-sports test (including the Anterior Cruciate Ligament-Return to Sport After Injury scale, Qualitative Assessment of Single-Leg Landing tool, limb symmetry index, and ability to change direction using the Modified Illinois Change of Direction Test).

RESULTS

The study included 111 matched pairs. At 6 months postoperatively, there were no significant differences between groups in the overall K-STARTS score (65.4 for isolated ACLR vs 61.2 for ACLR-ALLR, P = .087) or the Tegner Activity Scale score (3.7 for isolated ACLR vs 3.8 for ACLR-ALLR, P = .45). In addition, an evaluation of the subscales of the K-STARTS score revealed no disadvantage across the domains of neuromuscular control, limb symmetry index, agility, or psychological readiness to return to sport when an ALLR was performed.

CONCLUSIONS

The addition of ALLR at the time of ACLR does not delay functional recovery. Specifically, at 6 months postoperatively, there was no disadvantage in patients undergoing ALLR-ACLR, when compared with those undergoing isolated ACLR, with respect to neuromuscular control, limb symmetry indices (hop tests), agility, or psychological readiness to return to sport.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Influence of Patient Demographics and Surgical Characteristics on Pass Rates of Return-to-Activity Tests in Anterior Cruciate Ligament-Reconstructed Patients Before Physician Clearance

OBJECTIVE

To identify the frequency of passing return-to-activity tests after anterior cruciate ligament reconstruction (ACLR) and to investigate the influence of patient-specific factors on pass rates. We hypothesized that isolated strength tests would be most difficult to pass and that graft type would be the most influential factor.

DESIGN

Cross-sectional.

SETTING

Laboratory.

PARTICIPANTS

Eighty patients with a history of primary, unilateral ACLR, and 80 healthy controls participated.

INTERVENTIONS

Bilateral isokinetic strength, isometric strength, and single-leg hop tests were recorded during a single visit. The International Knee Documentation Committee (IKDC) Subjective Knee Evaluation measured subjective knee function, and the Tegner Activity Scale measured physical activity level.

MAIN OUTCOME MEASURES

Pass rates were calculated for 3 thresholds of absolute between-limb asymmetry: 0% to 10%, 11% to 15%, and 16% to 20%. Pass rates were compared by sex (male and female), graft type (patellar and hamstrings), meniscal procedure (yes and no), physical activity level (</≥ median Tegner), and time from surgery (</≥ 6 months).

RESULTS

Isokinetic quadriceps strength was consistently most difficult to pass, whereas the 6-meter timed hop and crossover hop tests were easiest. Graft type had the greatest influence on pass rates (isometric quadriceps and hamstring strength, hamstrings-to-quadriceps ratio), followed by time from surgery (6-meter timed hop and crossover hop), physical activity (IKDC), and meniscal procedure (6-meter timed hop).

CONCLUSIONS

Isokinetic quadriceps strength was the most difficult test to pass, and single-leg hop tests were the easiest. Patient-specific factors including graft type, time from surgery, physical activity level, and meniscal procedure may influence the ability to meet return-to-activity criterion after ACLR.

Prognostic Factors for Patient-Reported Outcomes at 32 to 37 Years After Surgical or Nonsurgical Management of Anterior Cruciate Ligament Injury

Background:

Knowledge to inform the identification of individuals with a poor long-term prognosis after anterior cruciate ligament (ACL) injury is limited. Identifying prognostic factors for long-term outcomes after ACL injury may inform targeted interventions to improve outcomes for those with a poor long-term prognosis.

Purpose:

To determine whether ACL treatment (early augmented or nonaugmented ACL repair plus rehabilitation, rehabilitation alone, or rehabilitation plus delayed ACL reconstruction [ACLR]) and 4-year measures (quadriceps and hamstrings strength, single-leg hop, knee laxity, flexion and extension deficit, self-reported knee function, activity level) are prognostic factors for patient-reported outcomes at 32 to 37 years after acute ACL injury.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

A total of 251 patients aged 15 to 40 years with acute ACL rupture between 1980 and 1985 were allocated to early ACL repair (augmented or nonaugmented) plus rehabilitation or to rehabilitation alone, based on birth year. One hundred ninety of 234 completed 32- to 37-year follow-up questionnaires (response rate, 81%); 18 people were excluded, resulting in 172 patients available for analysis (mean age, 59 ± 6 years; 28% female). Potential prognostic factors assessed 4 years after ACL injury were ACL treatment (early ACL repair, rehabilitation alone, or delayed ACLR), isokinetic quadriceps and hamstrings strength, single-leg hop performance, knee flexion and extension deficit, knee laxity, Tegner activity scale, and Lysholm score. Outcomes included Knee injury and Osteoarthritis Outcome Score (KOOS) subscales and the Anterior Cruciate Ligament Quality of Life (ACL-QOL) measure. Linear regression adjusted for age, sex, baseline meniscal injury, and contralateral ACL injury was used to assess potential prognostic factors for 32- to 37-year outcomes. Multiple imputation accounted for missing data.

Results:

A fair/poor Lysholm score (vs excellent/good) at 4 years was a prognostic factor for worse KOOS Pain (adjusted regression coefficient, −12 [95% confidence interval (CI), −19 to −4]), KOOS Symptoms (−15 [95% CI, −23 to −7]), KOOS Sport and Recreation (−19 [95% CI, −31 to −8]), and ACL QOL (−9 [95% CI, −18 to −1]) scores. A 4-year single-leg hop limb symmetry index <90% was a prognostic factor for worse KOOS Pain (adjusted regression coefficient, −9 [95% CI, −17 to −1]) and ACL QOL (−13 [95% CI, −22 to −3]) scores at long-term follow-up. A lower activity level, delayed ACLR, and increased knee laxity were prognostic factors in the crude analysis. Rehabilitation alone versus early repair, quadriceps and hamstring strength, and flexion and extension deficit were not related to 32- to 37-year outcomes.

Conclusion:

Reduced self-reported knee function and single-leg hop performance 4 years after ACL injury were prognostic factors for worse 32- to 37-year outcomes. Estimates exceeded clinically important thresholds, highlighting the importance of assessing these constructs when managing individuals with ACL injuries.

Registration:

NCT03182647 (ClinicalTrials.gov identifier).

Return to sport following anterior cruciate ligament reconstruction: the argument for a multimodal approach to optimise decision-making: current concepts

Existing literature is varied in the methods used to make this determination in the treatment of athletes who have undergone recent anterior cruciate ligament (ACL) reconstruction. Some authors report using primarily time-based criteria, while others advocate for physical measures and kinematic testing to inform decision-making. The goal of this paper is to elucidate the most current medical evidence regarding identification of the earliest point at which a patient may safely return to sport. The present review therefore seeks to examine the evidence from a critical perspective-breaking down the biology of graft maturation, effect of graft choice, potential for image-guided monitoring of progression and results associated with time-based versus functional criteria-based return to play-to justify a multifactorial approach to effectively advance athletes to return to sport. The findings of the present study reaffirm that time is a prerequisite for the biological progression that must occur for a reconstructed ligament to withstand loads demanded by athletes during sport. Modifications of surgical techniques and graft selection may positively impact the rate of graft maturation, and evidence suggests that imaging studies may offer informative data to enhance monitoring of this process. Aspects of both functional and cognitive testing have also demonstrated utility in prior studies and consequently have been factored into modern proposed methods of determining the athlete's readiness for sport. Further work is needed to definitively determine the optimal method of clearing an athlete to return to sport after ACL reconstruction. Evidence to date strongly suggests a role of a multimodal algorithmic approach that factors in time, graft biology and functional testing in return-to-play decision-making after ACL reconstruction.Level of evidence: level V.

The Role of Psychological Readiness in Return to Sport Assessment After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Knowledge about the predictive value of return to sport (RTS) test batteries applied after anterior cruciate ligament reconstruction (ACLR) is limited. Adding assessment of psychological readiness has been recommended, but knowledge of how this affects the predictive ability of test batteries is lacking.

PURPOSE

To examine the predictive ability of a RTS test battery on return to preinjury level of sport and reinjury when evaluation of psychological readiness was incorporated.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 129 patients were recruited 9 months after ACLR. Inclusion criteria were age ≥16 years and engagement in sports before injury. Patients with concomitant ligamentous surgery or ACL revision surgery were excluded. Baseline testing included single-leg hop tests, isokinetic strength tests, the International Knee Documentation Committee (IKDC) Subjective Knee Form 2000, a custom-made RTS questionnaire, and the Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scale. The RTS criteria were IKDC 2000 score ≥85% and ≥85% leg symmetry index on hop and strength test. At a 2-year follow-up evaluation, further knee surgery and reinjuries were registered and the RTS questionnaire was completed again. Regression analyses and receiver operating characteristic analyses were performed to study the predictive ability of the test battery.

RESULTS

Out of the 103 patients who completed the 2-year follow-up, 42% returned to their preinjury level of sport. ACL-RSI 9 months after surgery (odds ratio [OR], 1.03) and age (OR, 1.05) predicted RTS. An ACL-RSI score <47 indicated that a patient was at risk of not returning to sport (area under the curve 0.69; 95% CI, 0.58-0.79), with 85% sensitivity and 45% specificity. The functional tests did not predict RTS. Six patients sustained ACL reinjuries and 7 underwent surgery for other knee complaints/injuries after RTS testing. None of the 29 patients who passed all RTS criteria, and were therefore cleared for RTS, sustained a second knee injury.

CONCLUSION

ACL-RSI and age were predictors of 2-year RTS, while functional tests were not informative. Another main finding was that none of the patients who passed the 85% RTS criteria sustained another knee injury.

Is It Time We Better Understood the Tests We are Using for Return to Sport Decision Making Following ACL Reconstruction? A Critical Review of the Hop Tests

There has been a move towards a criterion-based return to play in recent years, with 4 single-leg hop tests commonly used to assess functional performance. Despite their widespread integration, research indicates that relationships between ‘passing’ ‘hop test criteria and successful outcomes following rehabilitation are equivocal, and, therefore, require further investigation. This critical review includes key information to examine the evolution of these tests, their reliability, relationships with other constructs, and sensitivity to change over time. Recommendations for how measurement and administration of the tests can be improved are also discussed. The evidence presented in this review shows that hop tests display good reliability and are sensitive to change over time. However, the use of more than 2 hop tests does not appear to be necessary due to high collinearity and no greater sensitivity to detect abnormality. The inclusion of other hop tests in different planes may give greater information about the current function of the knee, particularly when measured over time using both relative and absolute measures of performance. It is recommended that the contralateral limb be tested prior to surgery for a more relevant benchmark for performance, and clinicians are strongly advised to measure movement quality, as hop distance alone appears to overestimate the recovery of the knee.

Return to sport after anterior cruciate ligament injury: Panther Symposium ACL Injury Return to Sport Consensus Group

OBJECTIVES

A precise and consistent definition of return to sport (RTS) after anterior cruciate ligament (ACL) injury is lacking, and there is controversy surrounding the process of returning patients to sports and their previous activity level. The aim of the Panther Symposium ACL Injury RTS Consensus Group was to provide a clear definition of RTS after ACL injury and description of the RTS continuum, as well as provide clinical guidance on RTS testing and decision-making.

METHODS

An international, multidisciplinary group of ACL experts convened as part of a consensus meeting. Consensus statements were developed using a modified Delphi method. Literature review was performed to report the supporting evidence.

RESULTS

Key points include that RTS is characterised by achievement of the preinjury level of sport and involves a criteria-based progression from return to participation to RTS, and ultimately return to performance. Purely time-based RTS decision-making should be abandoned. Progression occurs along an RTS continuum with decision-making by a multidisciplinary group that incorporates objective physical examination data and validated and peer-reviewed RTS tests, which should involve functional assessment as well as psychological readiness. Consideration should be given to biological healing, contextual factors and concomitant injuries.

CONCLUSION

The resultant consensus statements and scientific rationale aim to inform the reader of the complex process of RTS after ACL injury that occurs along a dynamic continuum. Research is needed to determine the ideal RTS test battery, the best implementation of psychological readiness testing and methods for the biological assessment of healing and recovery.

Rehabilitation duration and time of starting sport-related activities associated with return to the previous level of sports after anterior cruciate ligament reconstruction

OBJECTIVES

To determine predictors for return to previous level of sports after anterior cruciate ligament reconstruction (ACLR).

DESIGN

Cross-sectional; SETTING: Athletic teams.

PARTICIPANTS

Ninety-one athletes who had ACLR with hamstring-tendon autograft within 1-5 years participated in this study. Athletes indicated their sport participation levels, injury profile, rehabilitation duration, and time to start sport-related activities (running, cutting-pivoting) after ACLR. Athletes answered whether they returned to the same previous level of frequency, duration, and intensity of sports.

MAIN OUTCOME MEASURES

Athletes' characteristics, injury and surgical factors, duration of post-operative rehabilitation program, and time to start sport-related activities after ACLR were evaluated by univariate logistic regression to determine predictors for return to previous level of sports.

RESULTS

Nine athletes (10%) returned to their self-described previous level of sports. Predictors for returning to previous level of sports were rehabilitation duration >4 months (OR:6.78; p = .011), time to start running ≤4 months (OR:8.62; p = .047) and cutting-pivoting <6 months after surgery (OR:5.02; p = .030).

CONCLUSION

Longer post-operative rehabilitation duration and time to start sport-related activities after ACLR predicted return to previous level of sports. Spending adequate time in post-operative rehabilitation program and time-based resumption of sports-related activities after ACLR might be key factors for returning to previous sports level.

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

OBJECTIVES

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

DESIGN

Prospective longitudinal study.

SETTING

Hospital outpatient physiotherapy department.

PARTICIPANTS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

Return to Sport Composite Test After Anterior Cruciate Ligament Reconstruction (K-STARTS): Factors Affecting Return to Sport Test Score in a Retrospective Analysis of 676 Patients

BACKGROUND

Return to sport (RTS) to the preinjury level is the main purpose after anterior cruciate ligament (ACL) reconstruction but the factors affecting the RTS are not completely known. Knee Santy Athletic Return to Sport (K-STARTS) is a composite test designed to assess readiness for RTS after ACL reconstruction.

PURPOSE

To determine the key factors that influence K-STARTS scores in a large cohort of patients after ACL reconstruction.

STUDY DESIGN

Case-control study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A retrospective analysis of prospectively collected data was undertaken. All patients who underwent ACL reconstruction surgery between March 2016 and May 2017 and also had a K-STARTS assessment at 6 months postoperatively were included. To identify factors influencing the K-STARTS score, an analysis of variance was performed. Age, sex, sports level, delay between injury and surgery, concomitant lesions, graft type, additional lateral tenodesis procedure, and participation in the RTS program were analyzed to identify factors influencing the K-STARTS score.

RESULTS

A total of 676 patients were included in the study. The K-STARTS score was significantly higher in male patients than in female patients (13.9 vs 12.4; P < 0.001), in younger patients (those aged <30 years vs older patients; 14.2 vs 12; P < 0.001), ACL reconstructions performed with hamstring tendon autografts compared with bone-patellar tendon-bone (13.5 vs 13.1; P = 0.03) and in those who completed a specific RTS program in addition to standard rehabilitation, compared with those who did not participate (17.1 vs 13.1; P < 0.001). However, the only factor that significantly influenced the K-STARTS score beyond the minimal detectable change threshold was the completion of the additional RTS program. The preinjury frequency of sports participation, whether the dominant limb was injured, time from injury to surgery, the presence of associated meniscal injuries, and whether a lateral tenodesis was performed did not significantly influence the K-STARTS score.

CONCLUSION

Completion of a specific RTS program, in addition to standard rehabilitation, was the most important factor influencing the K-STARTS composite functional and psychological RTS test score at 6 months after ACL reconstruction.

CLINICAL RELEVANCE

This study shows that the completion of a specific RTS program affects positively the RTS test score at 6 months after ACL reconstruction.

Confidence to Return to Play After Anterior Cruciate Ligament Reconstruction Is Influenced by Quadriceps Strength Symmetry and Injury Mechanism

BACKGROUND

Although the restoration of quadriceps strength symmetry is a primary rehabilitation goal after anterior cruciate ligament reconstruction (ACLR), little is known about the potential relationship between quadriceps strength symmetry and psychological readiness to return to play (RTP).

HYPOTHESIS

Quadriceps strength symmetry will be associated with psychological readiness to RTP after ACLR. Secondarily, injury mechanism will influence the association between quadriceps strength and psychological readiness to RTP.

STUDY DESIGN

Retrospective cohort.

LEVEL OF EVIDENCE

Level 3 (cohort study).

METHODS

A total of 78 female patients completed strength testing and the Injury-Psychological Readiness to Return to Sport (I-PRRS) scale at an outpatient clinical facility as part of return to sport testing after ACLR. Linear regression analysis was used to assess the relationship between the I-PRRS and the independent variables of interest (quadriceps strength symmetry and injury mechanism).

RESULTS

For all patients combined, a significant symmetry × mechanism interaction was found. When split by injury mechanism, a significant linear relationship was found between quadriceps strength symmetry and the I-PRRS score in patients who experienced a noncontact injury (n = 55; P = 0.01; R² = 0.24). No such relationship was found for those who experienced a contact injury (n = 23; P = 0.97; R² = 0.01).

CONCLUSION

Greater quadriceps strength symmetry was associated with greater psychological readiness to RTP in female athletes after ACLR. This relationship, however, was present only in those who experienced a noncontact injury.

CLINICAL RELEVANCE

Clinicians should consider both the physical and the psychological factors in assessing a patient's readiness to RTP. This may be particularly important for those who have experienced an ACL tear through a noncontact mechanism.

Force and Rate Metrics Provide Return-to-Sport Criterion after ACL Reconstruction

PURPOSE

Peak vertical ground reaction force and linear loading rate can be valuable metrics for return-to-sport assessment because they represent limb loading dynamics; yet, there is no defined cutoff criterion to differentiate between healthy and altered limb loading. Studies have shown that healthy individuals exhibit strong first-order relationships between gait variables whereas individuals with pathological conditions did not. Thus, this study sought to explore and exploit this first-order relationship to define a region of healthy limb dynamics, which individuals with pathological conditions would reside outside of, to rapidly assess individuals with altered limb loading dynamics for return to sport. We hypothesized that there would be a strong first-order linear relationship between vertical ground reaction force peak force and linear loading rate in healthy controls' limbs, which could be exploited to identify abnormal limb loading dynamics in post-anterior cruciate ligament reconstruction (ACLR) individuals.

METHODS

Thirty-one post-ACLR individuals and 31 healthy controls performed a running protocol. A first-order regression analysis modeled the relationship between peak vertical ground reaction forces and linear vertical ground reaction force loading rate in the healthy control limbs to define a region of healthy dynamics to evaluate post-ACLR reconstructed limb dynamics.

RESULTS

A first-order regression model aided in the determination of cutoff criteria to define a region of healthy limb dynamics. Ninety percent of the post-ACLR reconstructed limbs exhibited abnormal limb dynamics based on their location outside of the region of healthy dynamics.

CONCLUSION

This approach successfully delineated between healthy and abnormal limb loadings dynamics in controls and post-ACLR individuals. The findings demonstrate how force and loading rate-dependent metrics can help develop criteria for individualized post-ACLR return-to-sport assessment.

EFFECTS OF SURFACE ON TRIPLE HOP DISTANCE AND KINEMATICS

Background

The single leg triple hop (SLTH) test is often utilized by rehabilitation practitioners as a functional performance measure in a variety of patient groups. Accuracy and consistency are important when measuring the patient progress and recovery. Administering the SLTH test on different surfaces, consistent with the patient's sport, may affect the hop distances and movement biomechanics.

Purpose

The purpose of this study was to examine the effects of court and turf surfaces on the hop distance, limb symmetry index (LSI), and lower extremity kinematics of a SLTH test.

Methods

Recreationally active female participants (n=11, height 163.8 ± 7.1cm, mass 63.1 ± 7.1kg, age 18.9 ± 0.9yrs), without injury, volunteered to participate in the study. Three maximal effort SLTH test trials on two different surfaces (court, synthetic turf) were collected and analyzed using 3D motion analysis techniques. Outcome variables included SLTH test distances and LSI values and sagittal plane kinematics including trunk, hip, knee and ankle range of motion (ROM) during the last two landings of each SLTH test trial. The second landing involves an absorption phase and propulsion phase in contrast to the final landing which involves absorption and final balance on the single leg. Paired t-tests were used to determine differences between surfaces in hop distance and LSI values. Two-way repeated measures ANOVA were used to determine differences between surfaces in kinematic variables.

Results

The total SLTH test distance was not statistically different between the court (4.11 ± 0.47m) and turf (4.03 ± 0.42m, p=0.47) surfaces. LSI for the court surface was 100.8 ± 3.0% compared to 99.7 ± 3.0% for turf surface, which was not statistically different (p=0.30). Knee flexion ROM was significantly less (p=0.04) on the turf compared to the court surface during the second landing. Ankle flexion range of motion was also significantly less (p=0.03) during the second landing on turf compared to court.

Conclusions

Type of surface influenced landing kinematics but not total SLTH test distance. When evaluating the quality of landings during a SLTH test, it may be warranted to observe each type of landing and the type of surface used during single leg tests.

Level of Evidence

2.

Clinical Decision Algorithm Associated With Return to Sport After Anterior Cruciate Ligament Reconstruction

CONTEXT

Understanding the factors that predict return to sport (RTS) after anterior cruciate ligament reconstruction facilitates clinical decision making.

OBJECTIVE

To develop a clinical decision algorithm that could predict RTS and non-RTS based on the differences in the variables after anterior cruciate ligament reconstruction.

DESIGN

Cross-sectional study.

SETTING

University laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 150 athletes in any sport involving deceleration, jumping, cutting, or turning enrolled in the study. All participants answered the International Knee Documentation Committee and Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) questionnaires and performed balance and isokinetic tests.

MAIN OUTCOME MEASURE(S)

The classification and regression tree (CART) was used to determine the clinical decision algorithm associated with RTS at any level and RTS at the preinjury level. The diagnostic accuracy of the CART was verified.

RESULTS

Of the 150 participants, 57.3% (n = 86) returned to sport at any level and 12% (n = 18) returned to sport at the preinjury level. The interactions among the peak torque extension at 300°/s >93.55 Nm, ACL-RSI score >27.05 (P = .06), and postoperative time >7.50 months were associated with RTS at any level identified by CART and were factors associated with RTS. An ACL-RSI score >72.85% was the main variable associated with RTS at the preinjury level. The interaction among an ACL-RSI score of 50.40% to 72.85%, agonist : antagonist ratio at 300°/s ≤63.6%, and anteroposterior stability index ≤2.4 in these participants was the second factor associated with RTS at the preinjury level.

CONCLUSIONS

Athletes who had more quadriceps strength tended to RTS at any level more quickly, even with less-than-expected psychological readiness. Regarding a return at the preinjury level, psychological readiness was the most important factor in not returning, followed by a better agonist : antagonist ratio and better balance.

Who Passes Return-to-Sport Tests, and Which Tests Are Most Strongly Associated With Return to Play After Anterior Cruciate Ligament Reconstruction?

Background:

Return-to-sport (RTS) testing after anterior cruciate ligament (ACL) reconstruction (ACLR) surgery has become popular. It has been recommended that such testing should incorporate several domains, or set of tests, but it is unclear which are most associated with a successful RTS.

Purpose:

To determine (1) the proportion of patients who can pass a set of self-report and functional tests at 6 months after ACLR; (2) age, sex, and activity level differences between patients who pass and those who do not; and (3) whether specific types of tests are associated with a return to competitive sport at 12 months.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

This was a prospective longitudinal study of 450 patients who had primary ACLR. At 6 months postoperatively, patients completed 2 self-report measures, the International Knee Documentation Committee (IKDC) subjective knee form and ACL–Return to Sport after Injury (ACL-RSI) scale, and 3 functional measures: single hop and triple crossover hop for distance and isokinetic quadriceps strength. Limb symmetry index scores of ≥90 for functional tests, IKDC scores ≥85, and ACL-RSI scores ≥65 were considered indicators of satisfactory recovery. Proportional statistics and contingency analysis were used to determine associations between age, sex, preinjury sports level, and (1) meeting test thresholds and (2) RTS at 12 months.

Results:

Only 17 (3.8%) patients met all 5 test criteria at 6 months, and 95 (21%) patients did not pass any test. More of the younger patients (<21 years) passed all of the functional tests (P < .01), and more male patients met the IKDC threshold (P = .03). Patients who played level I sports before injury had the same pass rates as those who played level II/III sports. Patients who passed the thresholds for the ACL-RSI and IKDC scales had 4 and 3 times the odds, respectively, of RTS at 12 months (both P < .0001). Meeting the threshold for quadriceps strength or either of the hop tests at 6 months was not associated with RTS.

Conclusion:

At 6 months after ACLR, few patients met all of the thresholds of the common tests used to assess RTS ability, although younger patients had higher rates of passing the functional tests. Self-perceived symptoms/function and psychological readiness were associated with a return at 12 months.

A New Rating Scale for the Rapid Evaluation of High-Level Sports Ability

Background:

Nearly half of patients with an anterior cruciate ligament (ACL) injury who have returned to sport after ACL reconstruction can return to sports activity at a competitive level, so emphasis should be focused not only on the timing of return to the sport but also on measuring the ability to participate in high-level sports activity.

Purpose:

To develop and evaluate a new, self-administered rating scale for rapid evaluation of high-level sports ability among community-level athletes who return to sports after ACL reconstruction surgery.

Study Design:

Cohort study (diagnosis); Level of evidence, 2.

Methods:

We developed the new rating scale—the Knee Stability in Sports/Cutting-Pivoting Ability (KSS/CPA) scale—in 2 stages. Initially, we used a survey and roundtable discussion to achieve an expert consensus for the KSS/CPA scale from a group of independent orthopaedic experts. Next, 77 amateur athletes who underwent ACL reconstruction by a single surgeon were recruited for a background analysis of data to compare the new scale with results from the Marx activity rating scale, Tegner activity scale, International Knee Documentation Committee Subjective Knee Form, and self-assessment of overall knee function.

Results:

The KSS/CPA scale was applicable and effective for evaluating the high-level sports ability of community-level athletes who had returned to their sport after ACL reconstruction. Statistical analysis confirmed the test-retest reliability of the new rating scale (intraclass correlation coefficient, 0.85/0.84 postoperatively) as well as its internal consistency (Cronbach alpha coefficient, 0.73 preoperatively and 0.89 postoperatively), construct validity (Spearman correlation coefficient, >0.35 postoperatively), excellent discriminant validity, acceptable responsiveness, and reasonable minimal detectable change (<25).

Conclusion:

The KSS/CPA scale can act as a supplement to other clinical outcome measures for a more comprehensive evaluation of community-level athletes’ cutting-pivoting ability and knee stability.

RETURN TO PLAY AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

ABSTRACT The anterior cruciate ligament (ACL) tear represents more than half of all knee injuries in sports that involve body rotations and sudden changes of direction. Discharging the athlete for return to play (RTP) post-ACL reconstruction (ACLR) is a difficult task with multidisciplinary responsibility. For many years, a six-month period post-ACLR was adopted as the only criterion for RTP. However, it is now suggested that RTP should not be exclusively time-based, but to clinical data and systematic assessments. Despite the importance of post-ACLR factors for RTP, pre- and peri-ACLR factors must also be considered. Historically, ACLR is performed with the hamstring or autologous patellar tendons, although the choice of graft is still an open and constantly evolving theme. Anterolateral ligament reconstruction and repair of meniscal ramp tear associated with ACLR have recently been suggested as strategies for improving knee joint stability. Subjective questionnaires are easy to apply, and help identify physical or psychological factors that can hamper RTP. Functional tests, such as hop tests and strength assessment by means of isokinetic dynamometers, are fundamental tools for decision making when associated with clinical evaluation and magnetic resonance imaging. Recently, the capacity to generate force explosively has been incorporated into the muscle strength assessment. This is quantified through the rate of torque development (RTD). Due to characteristics inherent to the practice of sport, there is an extremely short time available for produce strength. Thus, RTD seems to better represent athletic demands than the maximum strength assessment alone. This review investigates the pre-, peri- and post-ACLR factors established in the literature, and shares our clinical practice, which we consider to be best practice for RTP. Level of evidence V; Specialist opinion.