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

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.

The 6-m Timed Hop Is Not a Suitable Clinical Assessment Tool for Use Following Anterior Cruciate Ligament Reconstruction

CONTEXT

Single-leg hop tests are used to assess functional performance following anterior cruciate ligament (ACL) reconstruction. Recording 6-m timed hop scores using a stopwatch increases the potential for misclassification of patient status due to the number of error sources present.

OBJECTIVE

To examine the consistency of pass/fail (>90% limb symmetry index [LSI]) decisions in athletes tested at discharge following ACL reconstruction during the 6-m timed hop and the agreement between different human raters using a stopwatch and an electronic timing system.

SETTING

Clinic, rehabilitation.

PARTICIPANTS

A total of 20 professional soccer players (age 24.6 [4.2] y; height 175.3 [10.2] cm; mass 73.6 [14.5] kg; 36 [10.5] wk following ACL reconstruction) volunteered to take part in this study.

MAIN OUTCOME MEASURES

Two individual raters recorded each trial of the 6-m timed hop test on each limb with a stopwatch and an electronic timing system acted as the criterion measure. LSI scores were also computed with a pass score >90% LSI.

RESULTS

No significant differences were observed between limbs for any scoring method (P > .05). Mean differences indicated the electronic timing system was slower than both human raters (P < .05). Five participants failed the test (<90% LSI) but on each occasion this was only recorded by one method of rating. Kappa statistics showed no agreement in LSI scores across all 3 methods of scoring (κ = -.13) and no agreement when comparing the light gates to individual raters and rater 1 versus 2 (κ < 0). 95% limits of agreement in LSI scores recorded values of approximately ±20%.

CONCLUSIONS

The 6-m timed hop test recorded using a stopwatch is not a valid measure to make clinical decisions following ACL reconstruction. Systematic bias between methods also suggests that a stopwatch and electronic timing system cannot be used interchangeably.

Partial resection of the infrapatellar fat pad during anterior cruciate ligament reconstruction has no effect on clinical outcomes including anterior knee pain

BACKGROUND

Anterior knee pain (AKP) is a major complication that occurs after anterior cruciate ligament reconstruction (ACLR), even when hamstring tendon (HT) grafts are used. Damage to the infrapatellar fat pad (IPFP) during arthroscopy can cause AKP. The purpose of this study was to evaluate the influence of IPFP preservation on clinical outcomes, including AKP, in patients who underwent ACLR with HT autografts using the inside-out technique.

METHODS

Forty-two patients who underwent primary ACLR with HT autografts were prospectively assessed for 2 years after surgery. They were randomly selected to undergo treatment with as much intercondylar IPFP preservation as possible or with intercondylar IPFP resection to confirm the ACL origin on the femoral and tibial sides, especially the femoral footprint in deep flexion of the knee joint. The total IPFP volume was calculated using sagittal MR images before and 6 months after surgery. The patients completed a subjective knee score questionnaire and were assessed for patellar tendon tenderness and pain with the half-squat test or single-leg hop test at 6 months and 2 years postoperatively.

RESULTS

There were no differences in the patient characteristics, including age, sex, BMI, time from injury to surgery, and meniscus tear. The difference in the total size of the IPFP preserved was significant (P = 0.004). However, there were no significant differences in the subjective knee scores. Moreover, there were no differences in the clinical assessment parameters between the IPFP preservation and resection groups.

CONCLUSIONS

The size of the IPFP decreased more in the resection group than in the preservation group at 6 months after surgery. However, partial IPFP resection, which was used to better visualize the origin of the ACL, had no effect on the clinical outcomes, including AKP.

LEVEL OF EVIDENCE

Level II.

Association between Functional Performance and Return to Performance in High-Impact Sports after Lower Extremity Injury: A Systematic Review

After lower extremity injury, only half of the injured athletes return to their pre-injury sports level. Even though functional performance tests are often used to make return to sport decisions, it is unknown whether functional performance is associated with return to performance after such injuries. The aim of this systematic review was to identify, critically appraise, and analyze studies that investigated the association of functional performance tests with return to performance after lower extremity injuries in athletes participating in high-impact sports. MEDLINE, Embase, Web of Science, and CINAHL were systematically searched for relevant studies. Articles were independently screened by two authors and data were obtained from each included study using a data extraction form. Two authors independently scored methodological quality using the Quality In Prognosis Studies tool. A qualitative best evidence synthesis was conducted. Eight studies reported the association of functional performance with return to performance after lower extremity injuries, involving 1,246 athletes after anterior or posterior cruciate ligament reconstruction. No studies were found on the association of functional performance with return to performance for lower extremity injuries other than after anterior or posterior cruciate ligament reconstruction. All included studies had a high risk of bias. Two studies found significant but small associations for selected hop tests after anterior cruciate ligament reconstruction. Low evidence of association between functional performance and return to performance was present after anterior cruciate ligament reconstruction for the triple hop for distance, the 6-meter timed hop, the side hop in female athletes, and for the combination of the single and crossover hop for distance. In athletes after posterior cruciate ligament reconstruction, the vertical jump showed a significant but small association with return to performance. There is no high-quality evidence that functional performance is associated with return to performance after lower extremity injuries in athletes practicing high-impact sports. Low quality evidence suggests small associations after anterior and posterior cruciate ligament reconstruction. No evidence exists for lower extremity injuries other than after anterior or posterior cruciate ligament reconstruction. Therefore, research on functional performance associated with return to performance is recommended in high-quality prospective cohort studies including athletes with any type of lower extremity injury.

Meniscus or Cartilage Injury at the Time of Anterior Cruciate Ligament Tear Is Associated With Worse Prognosis for Patient-Reported Outcome 2 to 10 Years After Anterior Cruciate Ligament Injury: A Systematic Review

OBJECTIVES

(1) To assess prognostic factors for patient-reported outcome measures (PROMs) and physical activity 2 to 10 years after anterior cruciate ligament reconstruction (ACLR) or anterior cruciate ligament (ACL) injury, and (2) to assess differences in prognostic factors between patients treated with ACLR and with rehabilitation alone.

DESIGN

Prognosis systematic review.

LITERATURE SEARCH

Systematic searches were performed in PubMed, Web of Science, and SPORTDiscus.

STUDY SELECTION CRITERIA

We selected prospective cohort studies and randomized clinical trials that included adults or adolescents undergoing either ACLR or rehabilitation alone after ACL rupture. Studies had to assess the statistical association between potential prognostic factors (factors related to patient characteristics, injury, or knee symptoms/function measured at baseline or within 1 year) and outcomes (PROMs and physical activity).

DATA SYNTHESIS

Our search yielded 997 references. Twenty studies met the inclusion criteria. Seven studies with low or moderate risk of bias remained for data synthesis.

RESULTS

Moderate-certainty evidence indicated that concomitant meniscus and cartilage injuries were prognostic factors for worse PROMs 2 to 10 years after ACLR. Very low-certainty evidence suggested that body mass index, smoking, and baseline PROMs were prognostic factors for worse outcome. Very low-certainty evidence suggested that female sex and a worse baseline Marx Activity Rating Scale score were prognostic factors for a worse Marx Activity Rating Scale score 2 to 10 years after ACLR. There was a lack of studies on prognostic factors after rehabilitation alone.

CONCLUSION

Concomitant meniscus and cartilage injuries were prognostic factors for worse long-term PROMs after ACLR. The certainty was very low for other prognostic factors. J Orthop Sports Phys Ther 2020;50(9):490-502. Epub 1 Aug 2020. doi:10.2519/jospt.2020.9451.

Early clinical and neuromuscular properties in patients with normal or sub-normal subjective knee function after anterior cruciate ligament reconstruction

PURPOSE

To determine clinical and neuromuscular properties in patients with normal or sub-normal subjective knee function after finalisation of 6 months' post-operative rehabilitation following anterior cruciate ligament reconstruction (ACLR).

METHODS

Sixty patients after primary anatomical single-bundle hamstring ACLR were prospectively enrolled. Demographics, subjective, clinical and functional status of the injured knee were recorded at baseline, 6 and 12 months post-operatively. Return to pre-injury activities time (months) was monitored. Tensiomyography and isokinetic dynamometry of thigh muscles were performed at 6 months, when standard ACLR rehabilitation is finalized. Based on their IKDC Subjective Knee Evaluation scores at 6 months, they were assigned into "Normal" or "Sub-normal" group. All the above measured parameters were then compared between the two groups.

RESULTS

At 6 months' timeline, 21 patients (35%) perceived their knee function as "Normal", while 39 (65%) were "Sub-normal". There were no differences in clinical status between both groups, but patients in Normal group achieved higher IKDC, Lysholm, Tegner scores as well as higher single-leg hop test. They were taller, had lower body mass index and more of them achieved their preinjury level of activity at 12 months (67% vs. 33%). Tensiomyography revealed higher biceps femoris as well as semitendinosus and semimembranosus radial displacement values on the operated leg in Normal group. Isokinetic dynamometry showed significantly higher normalised peak torque and average power of knee extensor muscles.

CONCLUSIONS

Patients who perceive their knee function as normal at 6 months following ACLR presented with better neuromuscular properties of the thigh muscles. Decreased hamstring stiffness seems to be the key to higher return-to-preinjury activity. Postoperative rehabilitation should be more focused on reducing hamstring stiffness in addition to improving knee extensor muscle strength. Level of evidence II (prospective cohort study).

Muscular Coordination of Single-Leg Hop Landing in Uninjured and Anterior Cruciate Ligament-Reconstructed Individuals

This study compared lower-limb muscle function, defined as the contributions of muscles to center-of-mass support and braking, during a single-leg hopping task in anterior cruciate ligament-reconstructed (ACLR) individuals and uninjured controls. In total, 65 ACLR individuals and 32 controls underwent a standardized anticipated single-leg forward hop. Kinematics and ground reaction force data were input into musculoskeletal models to calculate muscle forces and to quantify muscle function by decomposing the vertical (support) and fore-aft (braking) ground reaction force components into contributions by individual lower-limb muscles. Four major muscles, the vasti, soleus, gluteus medius, and gluteus maximus, were primarily involved in support and braking in both ACLR and uninjured groups. However, although the ACLR group demonstrated lower peak forces for these muscles (all Ps < .001, except gluteus maximus, P = .767), magnitude differences in these muscles' contributions to support and braking were not significant. ACLR individuals demonstrated higher erector spinae (P = .012) and hamstrings forces (P = .085) to maintain a straighter, stiffer landing posture with more forward lumbar flexion. This altered landing posture may have enabled the ACLR group to achieve similar muscle function to controls, despite muscle force deficits. Our findings may benefit rehabilitation and the development of interventions to enable faster and safer return to sport.

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

PURPOSE

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 and description of the RTS continuum, as well as to 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 characterized by achievement of the pre-injury level of sport and involves a criteria-based progression from return to participation to return to sport, and ultimately return to performance. Purely time-based RTS decision-making should be abandoned. Progression occurs along a 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 biologic assessment of healing and recovery.

LEVEL OF EVIDENCE

IV.

Importance of functional performance and psychological readiness for return to preinjury level of sports 1 year after ACL reconstruction in competitive athletes

PURPOSE

This study aimed to identify independent predictive factors for return to sports (RTS) after anterior cruciate ligament (ACL) reconstruction in competitive-level athletes and to determine optimal cut-off values for these factors at 6 months after surgery.

METHODS

A total of 124 competitive athletes (50 males and 74 females; mean age, 17.0 years; preinjury Tegner activity scale > 7) who underwent primary ACL reconstruction were enrolled. Assessments at 6 months after surgery consisted of knee functional tests [quadriceps index, hamstrings index, and single-leg hop for distance (SLH)] and 2 self-report questionnaires [IKDC subjective score and ACL-Return to Sport after Injury scale (ACL-RSI)]. At 1 year after surgery, athletes were classified into the RTS group (n = 101) or non-RTS group (n = 23) based on self-reported sports activities. After screening possible predictive factors of RTS, multivariate logistic regression and receiver operating characteristic curve analyses were performed to identify independent factors.

RESULTS

Multivariate logistic regression analysis identified SLH (odds ratio, 2.861 per 10 unit increase; P < 0.001) and ACL-RSI (odds ratio, 1.810 per 10 unit increase; P = 0.001) at 6 months as independent predictors of RTS at 1 year after surgery. Optimal cut-off values of SLH and ACL-RSI were 81.3% (sensitivity = 0.891; specificity = 0.609) and 55 points (sensitivity = 0.693; specificity = 0.826), respectively.

CONCLUSION

In competitive athletes, SLH < 81% and ACL-RSI < 55 points at 6 months after surgery were associated with a greater risk of unsuccessful RTS at 1 year after surgery. SLH and ACL-RSI at 6 months could serve as screening tools to identify athletes who have difficulties with returning to sports after ACL reconstruction.

LEVEL OF EVIDENCE

III.

Return to Sport After Anterior Cruciate Ligament Injury: Panther Symposium ACL Injury Return to Sport Consensus Group

Background

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 sport and their previous activity level.

Purpose

The aim of the Panther Symposium ACL Injury Return to Sport Consensus Group was to provide a clear definition of RTS after ACL injury and a description of the RTS continuum as well as provide clinical guidance on RTS testing and decision-making.

Study Design

Consensus statement.

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 characterized 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.

Better reporting standards are needed to enhance the quality of hop testing in the setting of ACL return to sport decisions: a narrative review

Background/aim

There is a lack of consistency in return to sport (RTS) assessments, in particular hop tests to predict who will sustain a reinjury following anterior cruciate ligament (ACL) reconstruction. Inconsistent test battery content and methodological heterogeneity might contribute to variable associations between hop test performance and subsequent injury. Our aim was to investigate whether commonly used hop tests are administered in a consistent manner and in accordance with reported guidelines.

Methods

We conducted a narrative review of studies that examined whether hop testing could differentiate RTS pass rates, reinjury and rerupture in athletes after ACL reconstruction. Our specific focus was on the methodological procedures of hop testing as this component is widely used to evaluate patients’ function and readiness to RTS.

Main findings

Substantial variation exists in RTS hop test administration, scoring and interpretation. Authors often failed to report important details of methods such as warm up activities, randomisation, number of trials, rest periods and landing requirements.

Conclusion

We recommend researchers provide clearer descriptions of how hop tests are performed to increase standardisation and promote accurate data collection. Absence of reporting to describe test methods and using different test procedures makes it difficult to compare study findings.

One in 5 Athletes Sustain Reinjury Upon Return to High-Risk Sports After ACL Reconstruction: A Systematic Review in 1239 Athletes Younger Than 20 Years

CONTEXT

Anterior cruciate ligament (ACL) reconstruction (ACLR) is frequently performed in patients younger than 20 years whose goal is to return to sport (RTS). Varying reinjury rates have been reported, and the factors responsible are unclear. Studies differ with regard to age, graft type, surgical techniques, postoperative rehabilitation, RTS guidelines, and methods used to determine ACL failures.

OBJECTIVE

To determine RTS rates; the effect of participation in high-risk sports, sex, and graft type on ACL reinjury rates; and whether objective test criteria before RTS correlate with lower reinjury rates.

DATA SOURCES

A systematic review of the literature from inception to May 31, 2019, was conducted using the PubMed and Cochrane databases.

STUDY SELECTION

Studies on transphyseal ACLR in athletes <20 years old with a minimum mean follow-up of 2 years that reported reinjury rates, the number that RTS, and detailed the type of sport were included.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

A total of 1239 patients in 8 studies were included; 87% returned to sport and 80% resumed high-risk activities. Of the patients, 18% reinjured the ACL graft and/or the contralateral ACL. Nine percent of patellar tendon autografts and 15% of hamstring autografts failed (odds ratio [OR], 0.52; P = 0.002). Of reinjuries, 90% occurred during high-risk sports. Male patients had a significantly higher rate of ACL graft failure than female patients (OR, 1.64; P = 0.01). There was no sex-based effect on contralateral ACL injuries. Only 1 study cited objective criteria for RTS.

CONCLUSION

A high percentage of athletes returned to sport, but 1 in 5 suffered reinjuries to either knee. Male patients were more likely to reinjure the ACL graft. Objective criteria for RTS were rarely mentioned or not detailed. The need for testing of knee stability, strength, neuromuscular control, agility, and psychological measures before RTS remains paramount in young athletes.

Leg asymmetry and muscle function recovery after anterior cruciate ligament reconstruction in elite athletes: a pilot study on slower recovery of the dominant leg

The aim of this study was to examine performance in hopping tests in male athletes after anterior cruciate ligament reconstruction (ACLR) in the 4-to-6 months post-surgery period. A total of 36 athletes (24 ACLR and 12 controls) participated in this study. The ACLR group consisted of athletes who had undergone an ACLR on their dominant side (ACL DG n=16) or non-dominant side (ACL NDG n=8). Participants completed the following functional tests: a single-leg hop (SLH), single-leg triple hop (SL3H) and single-leg counter movement jump (SLCMJ), then the limb symmetry index (LSI) was calculated. There were no significant differences between the dominant and the non-dominant legs for all functional tests when comparing the ACL DG and the ACL NDG at 6 months after surgery. At 6 months after ACLR, the LSI of the two legs was within acceptable values, whether the athlete had the operation on their dominant or non-dominant leg (except the mean LSI for the ACL DG in the SLCMJ test). Furthermore, the control group showed higher performances as compared to the ACL group for all variables at 6 months after surgery, despite acceptable LSI. We concluded that an early return to “full participation to training” is not recommended in participants who have undergone an ACLR with patellar tendon grafts.

Hop Testing Lacks Strong Association With Key Outcome Variables After Primary Anterior Cruciate Ligament Reconstruction: A Systematic Review

BACKGROUND

Single-legged hop tests are commonly used assessments in return to sport (RTS) testing after anterior cruciate ligament reconstruction (ACLR). Although these tests are commonly used, their predictive validity has not yet been established.

PURPOSE

To determine the strength of association between hop testing and RTS, knee reinjury, subjective report of knee function, and posttraumatic knee osteoarthritis (PTOA) after primary ACLR. Secondarily, to determine whether hop testing is able to predict a favorable result on the same outcome variables.

STUDY DESIGN

Systematic review.

METHODS

A systematic, computer-assisted literature search was performed in PubMed/MEDLINE, CINAHL, EMBASE, SPORTDiscus, Cochrane Library, and ClinicalTrials.gov. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed when conducting and reporting this review. Primary outcome variables for this review were self-report of knee function, return to preinjury level of activity, presence of reinjury, and presence of PTOA. The Oxford Centre for Evidence-Based Medicine Levels of Evidence tool was used to assess the level of evidence for each included study. Quality assessment of each included study was performed through use of a modified Downs and Black scale. Available metrics were tabulated based on outcome variables.

RESULTS

Overall, 21 studies (4476 patients) met inclusion for this review. The majority of evidence (95.2%) was of moderate to high methodologic quality. The most commonly associated outcome measure was the International Knee Documentation Committee (IKDC) score, with Pearson correlation coefficients ranging from 0.20 to 0.60. The strength of association between the Knee injury and Osteoarthritis Outcome Score (KOOS) and hop testing ranged from -0.10 to 0.62 in 4 studies. In all, 10 studies examined the relationship between hop testing and RTS, with variable association statistics reported. No meaningful association was found between hop testing and knee reinjury in 2 studies. Worse preoperative hop testing was associated with PTOA in 1 study.

CONCLUSION

Hop testing appears to possess fair association to subjective report of knee function measured by the KOOS and IKDC and a patient's ability to RTS after ACLR. Insufficient evidence is available to determine the relationship between hop testing and PTOA and knee reinjury. Predictive validity cannot be established based on available literature.

Compliance in post-operative rehabilitation is a key factor for return to sport after revision anterior cruciate ligament reconstruction

PURPOSE

To assess the rate of return to sport (RTS) following revision Anterior Cruciate Ligament Reconstruction (ACLR) in a rehabilitation-based cohort of patients. A secondary goal of the study was to evaluate the association between compliance in post-operative rehabilitation and RTS rate.

METHODS

The study cohort included 79 sport-active patients (62 males, 17 females, 30.0 ± 10.2 years old) who underwent revision ACLR surgery and followed the same functional-oriented rehabilitation protocol. Patients were evaluated using a RTS survey: return to any kind of sport participation, return to the same pre-injury sport, return to the same sport at the same pre-injury level. With regards to compliance in post-operative rehabilitation, patients were then grouped in (1) Fully Compliant (FC), (2) Moderately Compliant (MC), (3) Scarcely Compliant (SC), and (4) Non-Compliant (NC).

RESULTS

At an average follow-up of 29 ± 12 months, 86% of the patients returned to some kind of sport activity, 62% returned to the same pre-injury sport activity and 59% returned to the same pre-injury level of sport activity. While no surgical aspects were correlated with RTS, higher BMI was found to have a negative influence (p = 0.033). Regardless of the type of sport, compliance significantly affected RTS at the same pre-injury level (p = 0.006): 86% in FC, 67% in MC, 50% in SC, and 45% in NC. For each compliance goal achieved, the probability of RTS increased by 68% (OR = 1.68; p = 0.027).

CONCLUSION

RTS at the same pre-injury level after revision ACLR is challenging. A higher compliance in rehabilitation significantly increases the chances of RTS.

LEVEL OF EVIDENCE

IV.

Return to Sport Tests' Prognostic Value for Reinjury Risk after Anterior Cruciate Ligament Reconstruction: A Systematic Review

INTRODUCTION

Return to sports (RTS) clearance after anterior cruciate ligament (ACL) reconstruction typically includes multiple assessments. The ability of these tests to assess the risk of a reinjury remains unknown.

PURPOSE

To assess and rate RTS self-reported function and functional tests on prognostic value for reinjury risk after ACL reconstruction and RTS.

STUDY DESIGN

Systematic review on level 2 studies.

METHODS

PubMed, Web of Knowledge, Cochrane Library, and Google Scholar databases were searched for articles published before March 2018. Original articles in English or German that examined reinjury risks/rates after primary (index) ACL injury, ACL reconstruction, and RTS were included. All RTS functional tests used in the included studies were analyzed by retrieving an effect size with predictive value (odds ratio, relative risk (risk ratio), positive predictive value, positive likelihood ratio, or hazard rate).

RESULTS

A total of 276 potential studies were found; eight studies (moderate to high quality) on 6140 patients were included in the final analysis. The reinjury incidence recorded in the included studies ranged from 1.5% to 37.5%. Four studies reported a combination of isokinetic quadriceps strength at different velocities and a number of hop tests as predictive with various effect sizes. One reported isokinetic hamstring to quadriceps ratio (hazard rate = 10.6) as predictive. Two studies reported functional questionnaires (knee injury and osteoarthritis outcome score and Tampa Scale of Kinesiophobia-11; RR = 3.7-13) and one study showed that kinetic and kinematic measures during drop vertical jumps were predictive (odds ratio, 2.3-8.4) for reinjury and/or future revision surgery.

CONCLUSIONS

Based on level 2 evidence, passing a combination of functional tests with predetermined cutoff points used as RTS criteria is associated with reduced reinjury rates. A combination of isokinetic strength and hop tests is recommended during RTS testing.

No Relationship Between Strength and Power Scores and Anterior Cruciate Ligament Return to Sport After Injury Scale 9 Months After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Psychological factors including self-reported readiness to return to sport (RTS) after anterior cruciate ligament reconstruction (ACLR) measured with the Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) scale have been shown to correlate with RTS. Physical deficits have been shown to exist in the later stages after ACLR rehabilitation. No previous studies have investigated the relationship between self-reported readiness to RTS and objective physical measures of power and strength.

PURPOSE

To investigate the relationship between ACL-RSI scores and measures of strength and power scores after ACLR.

STUDY DESIGN

Case control study; Level of evidence, 3.

METHODS

This study recruited 452 male athletes who had undergone primary ACLR. Each athlete completed the ACL-RSI questionnaire, isokinetic strength testing, and jump testing approximately 9 months after surgery.

RESULTS

ACL-RSI scores showed a trivial or weak correlation with strength and power measures at 9 months after surgery (r = 0.06-0.16). Similar results were found for the relationship between ACL-RSI scores and limb symmetry index for strength and power measures (r = 0.04-0.15). Comparing the strength and power measures of athletes with higher (≥90) ACL-RSI scores (n = 93) versus athletes with lower (≤75) ACL-RSI scores (n = 92) showed no significant differences except for isokinetic hamstring strength, but with a trivial effect size (P = .040; effect size = 0.15).

CONCLUSION

Self-reported readiness to RTS as measured by the ACL-RSI had little or no relationship with athletes' strength and power measures, and there was no meaningful difference in strength and power between athletes with higher and lower ACL-RSI scores at 9 months after ACLR. The findings suggest that psychological recovery and physical recovery after ACLR are different constructs, and strategies to measure and address each construct separately may be necessary to ensure successful RTS after ACLR.

Which criteria are used to clear patients to return to sport after primary ACL reconstruction? A scoping review

OBJECTIVE

To describe the criteria used to clear athletes to return to sport (RTS) following primary ACL reconstruction.

DESIGN

Scoping review.

DATA SOURCES

MEDLINE, Embase, CINAHL and SPORTDiscus electronic databases were searched using keywords related to ACL and RTS.

ELIGIBILITY CRITERIA

Prospective or retrospective studies reporting at least one RTS criterion for athletes who had primary ACL reconstruction with an autograft.

RESULTS

In total, 209 studies fulfilled the inclusion criteria. RTS criteria were categorised into six domains: time, strength, hop testing, clinical examination, patient-report and performance-based criteria. From the 209 included studies, time was used in 178 studies (85%), and in 88 studies (42%) was the sole RTS criterion. Strength tests were reported in 86 studies (41%). Sixteen different hop tests were used in 31 studies (15%). Clinical examination was used in 54 studies (26%), patient report in 26 studies (12%) and performance-based criteria in 41 studies (20%).

SUMMARY

Time and impairment-based measures dominated RTS criteria, despite sport being a complex physical and biopsychosocial activity with demands across all aspects of function. Time was included as a criterion in 85% of studies, and over 80% of studies allowed RTS before 9 months. Whether RTS tests are valid-do they predict successful RTS?-is largely unknown.

Clinical Tests Can Be Used to Screen for Second Anterior Cruciate Ligament Injury in Younger Patients Who Return to Sport

Background:

Younger athletes have high rates of second anterior cruciate ligament (ACL) injury. Return-to-sport criteria have been proposed to enable athletes to make a safe return, but they frequently lack validation. It is unclear whether commonly recorded clinical measures can help to identify high-risk athletes.

Purpose:

To explore the association between commonly recorded clinical outcome measures and second ACL injury in a young, active patient group.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

Included in this study were 329 athletes (200 males, 129 females) younger than 20 years at the time of first primary ACL reconstruction surgery who had subsequently returned to sport participation. Clinical examination included range of knee motion (passive flexion and extension deficits), instrumented anterior knee laxity, and single- and triple-crossover hop for distance. Patients also completed the subjective International Knee Documentation Committee form. All measures were collected prospectively at a 12-month postoperative clinical review. Patients were evaluated for a minimum 3 years to determine the incidence of subsequent ACL injury.

Results:

A total of 95 patients (29%) sustained a second ACL injury following clinical assessment and return to sport. There were 50 graft ruptures and 45 contralateral ACL injuries. Patients with a flexion deficit of 5° had over 2 times the odds of sustaining a graft rupture (odds ratio, 2.3; P < .05), and patients with a side-to-side difference in anterior knee laxity of 3 mm or greater had over 2 times the odds of sustaining a contralateral ACL injury (odds ratio, 2.4; P < .05). Overall, 29% (94 of 329) of patients met the threshold for satisfactory function on all 6 clinical measures; these patients had a 33% reduction in the risk of sustaining a second ACL injury (P = .05) as compared with those who did not meet all clinical thresholds.

Conclusion:

Clinical measures of knee flexion and stability may have utility to screen for and identify patients who are at greater risk for a second ACL injury in an already high-risk group (ie, age and activity level).

Biomechanical and Functional Outcomes After Medial Patellofemoral Ligament Reconstruction: A Pilot Study

Background:

Previous studies have acknowledged the medial patellofemoral ligament (MPFL) as the primary stabilizer of the patella, preventing lateral displacement. MPFL reconstruction (MPFL-R) restores stability and functionality to the patellofemoral joint and has emerged as a preferred treatment option for recurrent lateral patellar instability.

Purpose:

To objectively measure biomechanical characteristics of athletes cleared for return to sport after MPFL-R compared with healthy controls.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A prospective case-control study design was employed on 31 total athletes. Sixteen athletes (6 male, 10 female; mean age, 16.1 ± 2.74 years; 385 ± 189 days after surgery and 235 ± 157 days after return to sport) underwent MPFL-R and were medically cleared to return to sport. This group was matched by age, sex, and activity level to 15 healthy athletes with no history of lower extremity injuries. Athletes and controls completed validated questionnaires as well as hopping, jumping, and cutting tests with 3-dimensional motion analysis and underwent strength, flexibility, laxity, and balance assessments.

Results:

Participants in the MPFL-R group scored significantly lower (worse) on the International Knee Documentation Committee (IKDC) (89.2 ± 7.6 vs 98.1 ± 2.0, respectively; P = .0005) and significantly higher (worse) on the Tampa Scale for Kinesiophobia (TSK) (32.4 ± 5.0 vs 25.4 ± 6.5, respectively; P = .006) than those in the control group, but there was no difference in the Kujala score (95.6 ± 5.3 vs 98.8 ± 3.0, respectively; P = .06). Participants in the MPFL-R group demonstrated reduced hip and ankle flexion relative to those in the control group (P < .05). Participants in the MPFL-R group also took significantly longer to complete the 6-m timed hop test relative to those in the control group (P < .05). No statistically significant differences were found in anthropometrics, knee extension or flexion strength, hamstring flexibility, hip abduction strength, or joint laxity between the MPFL-R and control groups.

Conclusion:

The current data indicate that MPFL-R generally restores functional symmetry, while subtle deficits in global power may remain after being released to full activity. Clinicians should ensure that athletes are fully rehabilitated before returning to sport after MPFL-R by emphasizing functional multijoint exercises.

Only one patient out of five achieves symmetrical knee function 6 months after primary anterior cruciate ligament reconstruction

PURPOSE

To assess the percentage of patients achieving symmetrical knee function 6 months after primary anterior cruciate ligament (ACL) reconstruction (ACLR) and to identify factors affecting its achievement, in a large cohort.

METHODS

Data were extracted from our clinic database. Patients who underwent primary ACLR from 2000 to 2015 and were assessed with the isokinetic quadriceps and hamstring muscles strength tests and single-leg-hop test at the 6-month follow-up were included in the study. Demographic data, information on the graft used, cartilage injuries and concomitant meniscal surgery were reviewed. Patients who reached a limb symmetry index (LSI) of ≥ 90% in all three tests were considered to have achieved symmetrical knee function. A multivariate logistic regression analysis was used to determine whether patient age, gender, time from injury to surgery, pre-injury Tegner activity level, graft type, cartilage injury and the presence of medial meniscus (MM) or lateral meniscus (LM) resection or repair were factors associated with the achievement of symmetrical knee function 6 months after primary ACLR.

RESULTS

A total of 4093 patients (54.3% males) with a mean age of 28.3 ± 10.7 years were included. Data from all three tests were available for 3541 patients. The proportion of patients that achieved a LSI of ≥ 90% was 35.7%, 47.3% and 67.9% for isokinetic quadriceps muscle strength, hamstring muscles strength and the single-leg-hop test, respectively. A total of 693 patients (19.6%) achieved symmetrical knee function, reaching a LSI of ≥ 90% in all three tests. Older age (≥ 30 years) (OR, 0.50; 95% CI 0.41-0.61; P < 0.001), MM resection (OR, 0.75; 95% CI 0.57-0.98; P = 0.03) and MM repair (OR, 0.63; 95% CI 0.40-0.98; P = 0.04) reduced the odds, whereas the use of hamstring tendon (HT) autograft (OR, 2.28; 95% CI 1.51-3.45; P < 0.001) over bone-patellar tendon-bone (BPTB) autograft increased the odds of achieving symmetrical knee function.

CONCLUSION

Only 19.6% of the patients achieved symmetrical knee function 6 months after primary ACLR. Age ≥ 30 years, MM resection and MM repair reduced the chance, whereas the use of HT autograft over BPTB autograft increased the chance of achieving symmetrical knee function 6 months after primary ACLR. This study shows that most of the patients are yet to regain symmetrical knee function 6 months after primary ACLR and, moreover, it identifies several factors affecting its achievement in a large cohort. The results of this study should be used to counsel patients about their expected functional recovery and to optimize rehabilitation and maximize knee function after ACLR.

LEVEL OF EVIDENCE

III.

Walking gait asymmetries 6 months following anterior cruciate ligament reconstruction predict 12-month patient-reported outcomes

The study sought to determine the association between gait biomechanics (vertical ground reaction force [vGRF], vGRF loading rate [vGRF-LR]) collected 6 months following anterior cruciate ligament reconstruction (ACLR) with patient-reported outcomes at 12 months following ACLR. Walking gait biomechanics and all subsections of the Knee Injury and Osteoarthritis Outcomes Score (KOOS) were collected at 6 and 12 months following ACLR, respectively, in 25 individuals with a unilateral ACLR. Peak vGRF and peak instantaneous vGRF-LR were extracted from the first 50% of the stance phase. Limb symmetry indices (LSI) were used to normalize outcomes in the ACLR limb to that of the uninjured limb (ACLR/uninjured). Linear regression analyses were used to determine associations between biomechanical outcomes and KOOS while accounting for walking speed. Receiver operator characteristic curves were used to determine the accuracy of 6-month biomechanical outcomes for identifying individuals with acceptable patient-reported outcomes, using previously defined KOOS cut-off scores, 12 months post-ACLR. Individuals with lower peak vGRF LSI 6 months post-ACLR demonstrated worse patient-reported outcomes (KOOS Pain, Activities of Daily life, Sport and Recreation, Quality of Life) at the 12-month exam. A peak vGRF LSI ≥0.99 6 months following ACLR associated with 13.33× higher odds of reporting acceptable patient-reported outcomes 12 months post-ACLR. Lesser peak vGRF LSI during walking at 6-months post-ACLR may be a critical indicator of worse future patient-reported outcomes. Clinical significance achieving early symmetrical lower extremity loading and minimizing under-loading of the ACLR limb during walking may be a potential therapeutic target for improving patient-reported outcomes post-ACLR. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2932-2940, 2018.

INFLUENCE OF PATIENT DEMOGRAPHICS AND GRAFT TYPES ON ACL SECOND INJURY RATES IN IPSILATERAL VERSUS CONTRALATERAL KNEES: A SYSTEMATIC REVIEW AND META-ANALYSIS

BACKGROUND

There are inconsistencies in the reported rates of second anterior cruciate ligament (ACL) injuries per limb, patients' sex and graft types after primary ACL reconstruction (ACLR). There are also inconsistencies regarding the influence of these factors on the occurrence of second ACL injury after primary ACLR.

PURPOSE

To determine the rate of second ACL injury, to either the ipsilateral graft or contralateral healthy ACL, as influenced by sex, age, and graft types and to determine the influence of sex, age, and graft types on the occurrence of second ACL injury after primary ACLR.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A computerized search of MEDLINE, CINAHL, and SPORTDiscus was conducted using combinations of these terms: ACL, ACLR, re-injury, re-rupture, revisions, contralateral tear, ipsilateral graft tear, and second injury. Articles were required to report the number or percentage of sex, graft type, ipsilateral graft and contralateral ACL injuries after ACLR. Rates of second ACL injuries and pooled dichotomous data were calculated using random-effect proportion meta-analysis.

RESULTS

The pooled rate of second ACL injuries (ipsilateral graft and contralateral ACL) was 6.11%. A slightly higher rate of ipsilateral graft injuries (3.29%) than contralateral ACL injuries (2.82%) (OR: 1.09 [95%CI: 0.89, 1.34] was reported. Ipsilateral graft injuries occurred earlier (median: 20 months) than contralateral ACL injuries (median: 36.3 months). Men had lower rate of second ACL injuries (5.67%) than women (6.84%) (OR: 0.92 [95%CI: 0.70, 1.20]). Significantly higher rate of ipsilateral graft injuries (3.40%) occurred in men compared to contralateral ACL injuries (2.26%) (OR: 1.53 [95CI%: 1.33, 1.77]), while women had significantly higher rate of contralateral ACL injuries (3.75%) compared to ipsilateral graft injuries (3.09%) (OR: 0.73 [95%CI: 0.55, 0.96]). The rate of second ACL (ipsilateral graft and contralateral ACL) injuries was higher in patients with hamstring tendon (HT) autograft (5.83%) than bone-patella tendon-bone autograft (BPTB) (5.10%) (p = 0.04) and allografts (3.12%) (p<0.0001). The rate of ipsilateral graft injuries was significantly higher than contralateral ACL injuries in all graft types (p<0.001).

CONCLUSION

Injuries to the ipsilateral graft are more common than contralateral ACL, with ipsilateral graft injuries occurring nearly 16 months earlier after ACLR. More women sustain second ACL injuries compared to men, with men incurring more injuries to the ipsilateral graft and women to the contralateral ACL. Furthermore, second ACL injuries are more common in patients with HT autograft, BPTB autograft, and then allograft; with ipsilateral graft injuries higher than contralateral ACL injuries regardless of graft types.

LEVELS OF EVIDENCE

2a.

Injury prevention and return to play strategies in elite football: no consent between players and team coaches

INTRODUCTION

Injuries are a common problem in football. To improve prevention strategies, the players' (p) and coaches' (c) views need to be disclosed as they have a strong impact on return to play decisions. The aim of this study is to reveal current opinions with regard to injury prevention and return to play strategies to introduce new strategies in elite football.

MATERIALS AND METHODS

In a retrospective data analysis of elite salaried football players (n = 486) and team coaches (n = 88), a detailed investigation by means of a standardized questionnaire was carried out. In a preseason period of the 2015/16 season and as part of a large interventional research project in elite salaried German football, a request about players' and team coaches' knowledge and opinions was performed. Topics such as injury prevention, return to play after injuries, the importance of screening tests, general problems of injuries in football, or the decision-making in terms of prevention and return to play in elite football were investigated.

RESULTS

The study revealed a high interest in injury prevention and screening tests among players and coaches (p 82.5%; c 99.1%). The participants of the study reported warm-up exercises (p 76.4%; c 74.7%), regeneration training (p 54.1%; c 56.3%), and core stability (p 53.8; c 70.1%) as the most important prevention methods, but the additional investigation of the teams' current daily training routine showed that the transfer is incomplete. Coaches are more familiar with scientific published warm-up programs like FIFA 11 + than players (42.5 vs. 12.6; p < 0.001). Knee injuries (p 90.7%; c 93.1%) and ACL injuries in particular were reported as the most severe and common problem in elite football. Players and coaches expressed different attitudes concerning return to play decisions. While players want to decide themselves (81.4%), team coaches consult medical advice ahead of the decision of return to play after injuries (83.5%; p < 0.001). Decisions against the doctor's recommendation are often made by both groups (p 64.4% vs. c 87.1%; p < 0.001).

CONCLUSION

The basic knowledge of prevention and injuries is sufficient in elite football, but the transfer from theoretical knowledge to practical routine is suboptimal. The study also shows possibilities to improve the prevention process and communication between players, coaches, doctors, and physiotherapists, while there is no consent between players and coaches regarding return to play decision.

Functional and Patient-Reported Outcomes Improve Over the Course of Rehabilitation: A Secondary Analysis of the ACL-SPORTS Trial

BACKGROUND

The Anterior Cruciate Ligament-Specialized Post-Operative Return to Sports (ACL-SPORTS) randomized controlled trial was designed to address deficits in functional and patient-reported outcomes. The trial examined the effects of a secondary ACL prevention program that included progressive strengthening, agility training, plyometrics (SAP), and other components of current primary prevention protocols, with perturbation training (SAP + PERT group) and without PERT (SAP group). A secondary purpose of this study was to examine whether study outcomes differed between men and women.

HYPOTHESES

(1) Athletes in both the SAP and SAP + PERT groups will have improved knee function and patient-reported outcome measures from pre- to posttraining, (2) the SAP + PERT group would have higher outcome scores than the SAP group, and (3) outcomes will differ by sex.

STUDY DESIGN

Randomized controlled trial (NCT01773317).

LEVEL OF EVIDENCE

Level 2.

METHODS

A total of 79 athletes (39 women) were randomized into the SAP and SAP + PERT groups. All athletes had undergone primary ACL reconstruction and achieved 80% quadriceps strength limb symmetry (QI), full range of motion, had minimal effusion, and had no pain. Additionally, all had begun running again. Prior to and after the training program, athletes' QI, hopping, and patient-reported outcomes were assessed. Repeated-measures analyses of variance were used to determine whether there were differences between groups. Subsequently, the SAP and SAP + PERT groups were collapsed to analyze differences between sexes.

RESULTS

There were significant increases for all variables, with the exception of QI. There were no differences between the SAP and SAP + PERT groups. Both men and women made significant improvements in all knee function and patient-reported outcome measures except QI. Men made significant improvements in QI, whereas women did not.

CONCLUSION

The common elements of the training program that all athletes received (10 sessions of progressive strengthening, agility training, plyometrics, and secondary prevention) may be a beneficial addition to the return-to-sport phase of ACL reconstruction rehabilitation. The results suggest that women may require further quadriceps strengthening to maintain and improve QI, an important focus given the relationship between QI and risk for reinjury.

CLINICAL RELEVANCE

During the return-to-sport phase of ACL reconstruction rehabilitation, clinicians tend to shift their focus away from strengthening toward more advanced sports-related tasks. These results indicate that women in particular need continued focus on quadriceps strengthening.