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

Blood Flow Restriction Training Applied With High-Intensity Exercise Does Not Improve Quadriceps Muscle Function After Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial

BACKGROUND

A major goal of rehabilitation after anterior cruciate ligament reconstruction (ACLR) is restoring quadriceps muscle strength. Unfortunately, current rehabilitation paradigms fall short of this goal, such that substantial quadriceps muscle strength deficits can limit return to play and increase the risk of recurrent injuries. Blood flow restriction training (BFRT) involves the obstruction of venous return to working muscles during exercise and may lead to better recovery of quadriceps muscle strength after ACLR.

PURPOSE

To examine the efficacy of BFRT with high-intensity exercise on the recovery of quadriceps muscle function in patients undergoing ACLR.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

A total of 34 patients (19 female, 15 male; mean age, 16.5 ± 2.7 years; mean height, 169.0 ± 19.7 cm; mean weight, 73.2 ± 17.7 kg) scheduled to undergo ACLR were randomly assigned to 1 of 4 groups: concentric (n = 8), eccentric (n = 8), concentric with BFRT (n = 9), and eccentric with BFRT (n = 9). The exercise component of the intervention consisted of patients performing a single-leg isokinetic leg press, at an intensity of 70% of the patients' 1-repetition maximum during either the concentric or eccentric action, for 4 sets of 10 repetitions 2 times per week for 8 weeks beginning at 10 weeks postoperatively. Patients randomized to the BFRT groups performed the leg-press exercise with a cuff applied to the thigh, set to a limb occlusion pressure of 80%. Isometric and isokinetic (60 deg/s) quadriceps peak torque, quadriceps muscle activation, and rectus femoris muscle volume were assessed before ACLR, after BFRT, and at the time that patients returned to activity and were converted to the change in values from baseline for analysis. Also, 1-way analyses of covariance were used to compare the change in values for each dependent variable between groups after BFRT and at return to activity (P ≤ .05).

RESULTS

No significant differences were found between groups for any outcome measures at either time point (P > .05).

CONCLUSION

An 8-week BFRT plus high-intensity exercise intervention did not significantly improve quadriceps muscle strength, activation, or volume. On the basis of our findings, the use of BFRT in conjunction with high-intensity resistance exercise in patients undergoing ACLR to improve quadriceps muscle function may not be warranted.

REGISTRATION

NCT03141801 ( ClinicalTrials.gov identifier).

Quadriceps Muscle Size Following ACL Injury and Reconstruction: A Systematic Review

Image-based assessments of quadriceps muscle size facilitate examination of structural changes after anterior cruciate ligament (ACL) injury and reconstruction (ACLR). Understanding the effects of ACLR on muscle size measures may aid in clarifying the contribution of quadriceps atrophy toward quadriceps strength. The purpose of this study was to systematically review the literature examining the effects of ACLR on quadriceps muscle volume and cross-sectional area (CSA). An online database search was conducted using Web of Science, SportDISCUS, PubMed (Medline), CINHAL (EBSCO), and Cochrane Library limited to articles published after January 1, 1980. Means and standard deviations were extracted for the ACLR limb and the contralateral limb, and sample characteristics from relevant articles. Magnitude of between limb differences were assessed using pooled effect sizes (Hedge's g) and 95% confidence intervals. Eleven articles (five CSA, six muscle volume) were included in this systematic review. Included studies reported negative effective sizes, indicating that the ACLR limb was smaller in CSA or muscle volume compared with the contralateral limb; however, 36% of the included articles reported meaningful difference between the limbs. Quadriceps atrophy may occur following ACL injury and persist after rehabilitation, however, the magnitude of these reductions may not be clinically meaningful and may only partially explain the persistent quadriceps weakness that is ubiquitous among this patient population. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:598-608, 2020.

Factors Influencing Return to Play and Second Anterior Cruciate Ligament Injury Rates in Level 1 Athletes After Primary Anterior Cruciate Ligament Reconstruction: 2-Year Follow-up on 1432 Reconstructions at a Single Center

BACKGROUND

Despite the importance of return-to-play (RTP) rates, second anterior cruciate ligament (ACL) injury rates, and patient-reported outcomes of athletes returning to sports after ACL reconstruction (ACLR), these outcomes have not been evaluated together across a single cohort nor the pre- and intraoperative factors influencing outcomes explored.

PURPOSE

To prospectively report outcomes after ACLR relating to RTP, second ACL injury, and International Knee Document Committee (IKDC) scores in a large cohort of athletes at a single center to examine the influence of pre- and intraoperative variables on these outcomes.

DESIGN

Cohort study; Level of evidence, 3.

METHODS

A consecutive cohort of 1432 athletes undergoing primary ACLR by 2 orthopaedic surgeons was followed up prospectively more than 2 years after surgery. Pre- and intraoperative findings were reported with outcomes at follow-up relating to RTP, second ACL injury, and IKDC. Between-group differences for each outcome were reported and the predictive ability of pre- and intraoperative variables relating to each outcome assessed with logistic regression.

RESULTS

There was >95% follow-up 2 years after surgery. The RTP rate was 81%, and of those who returned, 1.3% of those with patellar tendon grafts and 8.3% of those with hamstring grafts experienced ipsilateral rerupture (hazard ratio, 0.17). The contralateral ACL injury rate was 6.6%, and the IKDC score at follow-up was 86.8, with a greater proportion of patients with patellar tendon grafts scoring <80 on the IKDC (odds ratio, 1.56; 95% CI, 1.15-3.12). There was no relationship between time to RTP and second ACL injury, and there was a moderate correlation between ACL-Return to Sport After Injury score and RTP at follow-up (P < .001, rho = 0.46). There were a number of differences in pre- and intraoperative variables between groups for each outcome, but they demonstrated a poor ability to predict outcomes in level 1 athletes at 2-year follow-up.

CONCLUSION

Findings demonstrated high overall RTP rates, lower reinjury rates with patellar tendon graft after 2-year follow-up in level 1 athletes, and no influence of time to RTP on second ACL injury. Despite differences between groups, there was poor predictive ability of pre- and intraoperative variables. Results suggest pre- and intraoperative variables for consideration to optimize outcomes in level 1 athletes after ACLR, but future research exploring other factors, such as physical and psychological recovery, may be needed to improve outcome prediction after ACLR.

REGISTRATION

NCT02771548 (ClinicalTrials.gov identifier).

Activity and functional readiness, not age, are the critical factors for second anterior cruciate ligament injury - the Delaware-Oslo ACL cohort study

OBJECTIVE

To elucidate the relationships between age, return to level I sport (RTS) within the first postoperative year, passing RTS criteria and second anterior cruciate ligament (ACL) injury.

METHODS

In a prospective cohort study, 213 athletes were followed for 2 years after ACL reconstruction to record second ACL injuries. Independent variables were age, passing RTS criteria and level I RTS within the first postoperative year (vs later or no RTS). We defined passing RTS criteria as ≥90 on the Knee Outcome Survey - Activities of Daily Living Scale, global rating scale of function and quadriceps strength/hop test symmetry.

RESULTS

The follow-up rate was >87% for all outcomes. In multivariable analysis, level I RTS within the first postoperative year and passing RTS criteria were highly associated with second ACL injury (level I RTS HR: 6.0 (95% CI: 1.6 to 22.6), pass RTS criteria HR: 0.08 (95% CI: 0.01 to 0.6)), while age was not (age HR: 0.96 (95% CI: 0.89 to 1.04)). Athletes <25 years had higher level I RTS rates in the first postoperative year (60.4%) than older athletes (28.0%). Of those who returned to level I sport in the first postoperative year, 38.1% of younger and 59.1% of older athletes passed RTS criteria.

CONCLUSION

High rates of second ACL injury in young athletes may be driven by a mismatch between RTS rates and functional readiness to RTS. Passing RTS criteria was independently associated with a lower second ACL rate. Allowing more time prior to RTS, and improving rehabilitation and RTS support, may reduce second ACL injury rates in young athletes with ACL reconstruction.

Unanticipated jump-landing quality in patients with anterior cruciate ligament reconstruction: How long after the surgery and return to sport does the re-injury risk factor persist?

BACKGROUND

Inadequate reactions to unforeseen external stimuli are regarded as a major cause for non-contact anterior cruciate ligament (ACL) injuries. We aimed to delineate a potential deficit in the ability to perform unanticipated jump-landing manoeuvres, its sustainability and potential as a new outcome measure after ACL-reconstruction.

METHODS

Physically active adults (n = 27, 13 females, 14 males, 29.7 standard deviation 3.1 years) with a history of unilateral ACL rupture and subsequent reconstruction (6 months to 7 years ago), cleared for return to sports, were included. All participants performed counter-movement jumps with unanticipated single leg landings. Visual information shown after jump take-off indicated the required landing leg. Jump time [s] and successfulness [yes/no], vertical peak ground reaction forces at landing [N], as well as time to stabilisation after landing [s] and path length of the centre of pressure (CoP, [mm]) were calculated. Limb symmetry ratios were determined and analysed for their association with the time since surgery.

FINDINGS

Time since ACL reconstruction was logarithmically (basis 10) associated with side symmetry improvements in peak ground reaction force (R² = 0.23, p < .01) and time to stabilisation (R² = 0.18, p < .01) during and after landing in unanticipated/unpredictable single-leg jump landing tasks. The asymmetry found persists up to 18-26 months post-surgery.

INTERPRETATION

A deficit in unanticipated jump-landing ability seems to persist far beyond surgical restoration of mechanical stability and resumption of initial physical activities levels. The assessment of the ability to suddenly adapt movements to unanticipated visual stimuli may be a relevant complementary component within current functional testing canon in monitoring therapy success and return to sport testing.

Paediatric and adolescent anterior cruciate ligament reconstruction surgery

Aims

Anterior cruciate ligament (ACL) surgery in children and the adolescent population has increased steadily over recent years. We used a national database to look at trends in ACL reconstruction and rates of serious complications, growth disturbance, and revision surgery, over 20 years.

Methods

All hospital episodes for patients undergoing ACL reconstruction, under the age of 20 years, between 1 April 1997 and 31 March 2017, were extracted by procedure code from the national Hospital Episode Statistics (HES). Population standardized rates of intervention were determined by age group and year of treatment. Subsequent rates of serious complications including reoperation for infection, growth disturbance (osteotomy, epiphysiodesis), revision reconstruction, and/or contralateral ACL reconstruction rates were determined.

Results

Over the 20 year period, 16,125 ACL reconstructions were included. The mean age of patients was 16.9 years (SD 2.0; 27.1% female, n = 4,374/16,125). The majority of procedures were observed in the 15 to 19 years age group. The rate of ACL reconstruction increased 29-fold from 1997 to 1998, to 2016 to 2017. Within 90 days of ACL reconstruction, the rate of reoperation for infection was 0.31% (95% confidence interval (CI) 0.23 to 0.41, n = 50/16,125) and the rate of pulmonary embolism was 0.037% (95%.CI 0.014 to 0.081, n = 6/16,125). Of those with minimum five-year follow-up following ACL reconstruction (n = 7,585), 1.00% of patients subsequently underwent an osteotomy (95% CI 0.79 to 1.25, n = 76/7,585), 0.09% an epiphysiodesis (95% CI 0.04 to 0.19, n = 7/7,585), 7.46% revision ACL reconstruction (95% CI 6.88 to 8.08, n = 566/7,585), and 6.37% contralateral ACL reconstruction (95% CI 5.83 to 6.94, n = 483/7,585).

Conclusion

Rates of paediatric and adolescent ACL reconstruction have increased 29-fold over the last 20 years. Despite the increasing rate in the younger population, the risk of serious complications, including further surgery for growth disturbance is very low. The results of our study provide a point of reference for shared decision making in the management of ACL injury in the paediatric and adolescent population. Cite this article: Bone Joint J 2020;102-B(2):239–245.

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.

Young Athletes Who Return to Sport Before 9 Months After Anterior Cruciate Ligament Reconstruction Have a Rate of New Injury 7 Times That of Those Who Delay Return

OBJECTIVE

To investigate the association between sustaining a second anterior cruciate ligament (ACL) injury and (1) time to return to sport, (2) symmetrical muscle function, and (3) symmetrical quadriceps strength at the time of return to sport in young athletes after primary ACL reconstruction.

DESIGN

Prospective cohort study.

METHODS

Patient demographics and results from 5 tests of muscle function (2 strength tests and 3 hop tests) were extracted from a rehabilitation registry. A questionnaire was sent to athletes (15-30 years old) who were involved in knee-strenuous sport before the injury and had undergone primary ACL reconstruction to determine time of return to knee-strenuous sport (preinjury Tegner Activity Scale score of 6 or greater). We used the Cox proportional hazard regression model to analyze time to event.

RESULTS

One hundred fifty-nine (32% of the initial sample) athletes (mean ± SD age, 21.5 ± 4.4 years; 64% female) were included. Athletes with a higher preinjury Tegner Activity Scale score had a higher rate of second ACL injury (hazard ratio = 2.1; 95% confidence interval: 1.2, 3.6; P<.01). Athletes who returned to knee-strenuous sport before 9 months after reconstruction had a higher rate of second ACL injury (hazard ratio = 6.7; 95% confidence interval: 2.6, 16.7; P<.001). There was no association between symmetrical muscle function or quadriceps strength and second ACL injury.

CONCLUSION

Returning to knee-strenuous sport before 9 months after ACL reconstruction was associated with an approximately 7-fold increased rate of sustaining a second ACL injury. Achieving symmetrical muscle function or quadriceps strength was not associated with new ACL injury in young athletes. J Orthop Sports Phys Ther 2020;50(2):83-90. doi:10.2519/jospt.2020.9071.

Quadriceps and Hamstring Strength Symmetry After Anterior Cruciate Ligament Reconstruction: A Prospective Study

OBJECTIVES

To evaluate change in involved and uninvolved quadriceps and hamstring strength and limb symmetry indices (LSI) in regular intervals over the first 6 months following anterior cruciate ligament reconstruction (ACLR).

DESIGN

Prospective cohort study.

PARTICIPANTS

Thirty-eight male participants (mean age: 24.2 [6.4] y, mean body mass index: 23.6 [4.2] kg/m2), who underwent ACLR were included.

MAIN OUTCOME MEASURES

Isometric strength testing of the quadriceps and hamstring muscles was performed at 1, 2, 3, and 6 months after ACLR. Quadriceps and hamstring peak torques for each limb and LSI were calculated. Repeated-measures analysis of covariance and paired t tests were used to evaluate changes in strength over time and between limbs, respectively.

RESULTS

Quadriceps and hamstring peak torques of the involved limb consistently increased between each time point from 1 to 6 months (P < .001 and P = .01, respectively), whereas the uninvolved limb values did not change after ACLR (P > .05). In addition, uninvolved limb peak torque values were higher than involved limb values at each time point after ACLR for both the quadriceps and hamstrings (all P < .01). At 6 months after ACLR, 28.9% of participants demonstrated LSI greater than 90% for quadriceps strength, 36.8% demonstrated LSI greater than 90% for hamstring strength, and 15.8% of participants demonstrated greater than 90% LSI for both quadriceps and hamstring strength.

CONCLUSIONS

Participants demonstrated a consistent increase in quadriceps and hamstring strength of the involved limb, with no notable change in uninvolved limb strength over the 6 months after ACLR. However, at 6 months after ACLR, only approximately 16% of participants demonstrated both quadriceps and hamstring strength LSI greater than 90%, the typically recommended cutoff value for return to sport.

Evidence too weak to guide surgical treatment decisions for anterior cruciate ligament injury: a systematic review of the risk of new meniscal tears after anterior cruciate ligament injury

OBJECTIVE

To investigate the risk of new meniscal tears after treatment for anterior cruciate ligament (ACL) injury, in children and adults with and without ACL reconstruction.

DESIGN

Prognosis systematic review (PROSPERO registration number CRD42016036788).

METHODS

We searched Embase, Ovid Medline, Cochrane, CINAHL, SPORTDiscus, PEDro and Google Scholar from inception to 3rd May 2018. Eligible articles included patients with ACL injury (diagnosis confirmed by MRI and/or diagnostic arthroscopy), reported the number of meniscal tears at the time of ACL injury diagnosis/start of treatment and reported the number of new meniscal tears that subsequently occurred. Articles with fewer than 20 patients at follow-up, and articles limited to ACL revision surgery or multi-ligament knee injuries were excluded. Two independent reviewers screened articles, assessed eligibility, assessed risk of bias and extracted data. We judged the certainty of evidence using the Grading of Recommendations Assessment Development and Evaluation (GRADE) working group methodology.

RESULTS

Of 75 studies included in the systematic review, 54 studies with 9624 patients and 501 new meniscal tears were appropriate for quantitative analysis. Heterogeneity precluded data pooling. The risk of new meniscal tears was 0%-21% when follow-up was <2 years, 0%-29% when follow-up was 2 to 5 years, 5%-52% when follow-up was 5 to 10 years and 4%-31% when follow-up was longer than 10 years. The proportion of studies with high risk of selection, misclassification and detection bias was 84%, 69% and 68%, respectively. Certainty of evidence was very low.

CONCLUSION

New meniscal tears occurred in 0%-52% of patients between 4 months and 20 years (mean 4.9±4.4 years) following treatment for ACL injury. The certainty of evidence was too low to guide surgical treatment decisions. This review cannot conclude that the incidence of new meniscal tears is lower if ACL injury is treated with surgery compared with treatment with rehabilitation only.

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.

Corticomotor function is associated with quadriceps rate of torque development in individuals with ACL surgery

Impaired corticomotor function arising from altered intracortical and corticospinal pathways are theorized to impede muscle recovery following anterior cruciate ligament (ACL) surgery, yet functional implications of centrally driven adaptations remain unclear. We aimed to assess relationships between quadriceps corticomotor and neuromechanical function after ACL surgery, and to compare with contralateral and control limbs. 16 individuals after primary, unilateral ACL surgery and 16 sex- and age-matched controls participated. Corticomotor function was assessed using transcranial magnetic stimulation, and quantified via active motor thresholds (AMT), short-interval intracortical inhibition (SICI), and intracortical facilitation (ICF). Neuromechanical function was quantified via electromechanical delay, early and late-phase rate of torque development (RTD_0-50, RTD_100-200), coefficient of variation, maximal voluntary isometric contraction (MVIC) torque, and central activation ratio. We observed significant correlations in the ACL limbs between: AMT and RTD_0-50 (r = - 0.513, p = 0.031), SICI and RTD_100-200 (r = 0.501, p = 0.048), AMT and SICI (r = - 0.659, p = 0.010), AMT and ICF (r = 0.579, p = 0.031), RTD_0-50 and MVIC (r = 0.504, p = 0.023), and RTD_100-200 and MVIC (r = 0.680, p = 0.002). The ACL limbs demonstrated higher AMT compared to controls (44.9 ± 8.4 vs. 30.1 ± 8.2%, p < 0.001), and lesser MVIC torque (2.37 ± 0.52 vs. 2.80 ± 0.59 Nm/kg, p = 0.005) and RTD_100-200 (6.79 ± 1.72 vs. 7.90 ± 1.98 Nm/kg/s, p = 0.006) compared to the contralateral limbs. Our findings indicate that lesser corticospinal excitability is associated with lesser early-phase RTD, and greater intracortical inhibition is associated with lesser late-phase RTD. These findings provide evidence of implications of altered intracortical and corticospinal pathways relative to the ability to rapidly generate quadriceps torque following ACL surgery.

Integrating the Evidence and Clinical Expertise in the Shared Decision and Graduated Return to Sport Process: A Time Series Case Study after Anterior Cruciate Ligament Rupture and Reconstruction

INTRODUCTION

Rehabilitation following anterior cruciate ligament (ACL) rupture is often characterized by a large discrepancy between the available scientific evidence and its implementation into practice.

PURPOSE

We aimed to research, selectively rate, and transfer the available evidence to the returntosport (RTS) process after ACL rupture adopting an athlete time series case study design.

CASE REPORT AND METHODS

The participant is a male athlete aged 33 who was diagnosed with an isolated right-sided total ACL rupture. Knee arthroscopy using semitendinosus tendon plastic (×4) was performed. For rehabilitation, a graded and shared decision RTS algorithm was derived from the existing evidence and all relevant decision-makers expertise. Starting with basic functional abilities and range of motion, the functional ability at each stage had to be achieved before the next stage was aimed. The corresponding therapeutic focus (in addition to standard therapy) was adopted to reach this goal. Functions to be tested were as follows: Knee function confidence, dynamic balance, isometric and isokinetic strength/torque testing, as well as jumping ability (single-leg hop and triple crossover hop for distance).

RESULTS

RTS was reached (Level 3) 5 months and (Level 2) 10 months post-surgery.

CONCLUSION

Integrating the available evidence and the clinical expertise of all relevant stakeholders into a shared decision and graduated RTS process after ACL rupture and reconstruction was feasible and successful. Particularly, multiple functional measurements in a time series approach to determine the actual rehabilitation focus seem promising.

Clinical outcomes after anterior cruciate ligament injury: panther symposium ACL injury clinical outcomes consensus group

PURPOSE

A stringent outcome assessment is a key aspect for establishing evidence-based clinical guidelines for anterior cruciate ligament (ACL) injury treatment. The aim of this consensus statement was to establish what data should be reported when conducting an ACL outcome study, what specific outcome measurements should be used and at what follow-up time those outcomes should be assessed.

METHODS

To establish a standardized approach to assessment of clinical outcome after ACL treatment, a consensus meeting including a multidisciplinary group of ACL experts was held at the ACL Consensus Meeting Panther Symposium, Pittsburgh, PA; USA, in June 2019. The group reached consensus on nine statements by using a modified Delphi method.

RESULTS

In general, outcomes after ACL treatment can be divided into four robust categories-early adverse events, patient-reported outcomes, ACL graft failure/recurrent ligament disruption and clinical measures of knee function and structure. A comprehensive assessment following ACL treatment should aim to provide a complete overview of the treatment result, optimally including the various aspects of outcome categories. For most research questions, a minimum follow-up of 2 years with an optimal follow-up rate of 80% is necessary to achieve a comprehensive assessment. This should include clinical examination, any sustained re-injuries, validated knee-specific PROs and Health-Related Quality of Life questionnaires. In the mid- to long-term follow-up, the presence of osteoarthritis should be evaluated.

CONCLUSION

This consensus paper provides practical guidelines for how the aforementioned entities of outcomes should be reported and suggests the preferred tools for a reliable and valid assessment of outcome after ACL treatment.

LEVEL OF EVIDENCE

V.

Pediatric Anterior Cruciate Ligament Reconstruction

The increasing incidence of anterior cruciate ligament injuries in skeletally immature children demands careful attention by orthopedic surgeons. Assessing skeletal age is essential to selecting the appropriate reconstruction technique. Males with a bone age of 15 years or older and females of 13 years and older are ideal candidates for a transphyseal anterior cruciate ligament reconstruction because there is minimal risk of growth disturbance. Children with substantial growth remaining (skeletal age males ≤12 years and females ≤10 years) seem to be at risk for more significant growth disturbance, so we generally recommend physeal-sparing techniques for these younger patients.

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of anterior cruciate ligament injury - Secondary publication

BACKGROUND

This clinical guideline presents recommendations for the management of patients with anterior cruciate ligament (ACL) injury, endorsed by the Japanese Orthopaedic Association (JOA) and Japanese Orthopaedic Society of Knee, Arthroscopy and Sports Medicine (JOSKAS).

METHODS

The JOA ACL guideline committee revised the previous guideline based on "Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014", which proposed a desirable method for preparing clinical guidelines in Japan. Furthermore, the importance of "the balance of benefit and harm" was also emphasized. This guideline consists of 21 clinical questions (CQ) and 23 background questions (BQ). For each CQ, outcomes from the literature were collected and evaluated systematically according to the adopted study design.

RESULTS

We evaluated the objectives and results of each study in order to make a decision on the level of evidence so as to integrate the results with our recommendations for each CQ. For BQ, the guideline committee proposed recommendations based on the literature.

CONCLUSIONS

This guideline is intended to be used by physicians, orthopedic surgeons, physical therapists, and athletic trainers managing ACL injuries. We hope that this guideline is useful for appropriate decision-making and improved management of ACL injuries.

Superior knee self-efficacy and quality of life throughout the first year in patients who recover symmetrical muscle function after ACL reconstruction

PURPOSE

The aim of this study was to (1) describe psychological outcomes during the first year after an anterior cruciate ligament (ACL) reconstruction and (2) compare psychological outcomes in patients who recover symmetrical muscle function with patients who do not.

METHODS

The included patients had undergone a unilateral ACL reconstruction. Patients with a re-rupture and contralateral ACL injury were excluded. Three groups, based on the results from 5 tests of muscle function 12 months after reconstruction, were created. Three validated questionnaires (the Knee Self-Efficacy Scale; the Knee injury and Osteoarthritis Outcome Score subscale "Quality of Life"; the ACL Return to Sport after Injury scale) and a single question "Have you achieved your goal with rehabilitation?" were analysed in 4 different follow-ups after ACL reconstruction (10 weeks, 4, 8 and 12 months). Means and standard deviations were analysed with standard t tests and reported with 95% confidence intervals.

RESULTS

A total of 328 patients (120 men, 37%), mean age 27.8 ± 10 years, were included. Patients who did not recover symmetrical muscle function (n = 56; 17%) at the 12-month follow-up reported inferior knee-related self-efficacy and quality of life than patients who recovered symmetrical muscle function (n = 96; 29%) at all follow-ups, except quality of life at 4 months. The proportion of patients who stated they achieved their rehabilitation goal at 12 months was 17% for the entire cohort, 24% for patients who recovered muscle function and 5% for patients who did not recover muscle function.

CONCLUSION

Patients who recovered strength and hop symmetry 12 months after ACL reconstruction had superior knee-related self-efficacy and greater quality of life during the whole first year after ACL reconstruction. These results can aid clinicians in the decision-making process by providing knowledge of patients who might need further attention during rehabilitation.

LEVEL OF EVIDENCE

III.

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.

Age, gender, quadriceps strength and hop test performance are the most important factors affecting the achievement of a patient-acceptable symptom state after ACL reconstruction

PURPOSE

To assess the percentage of patients achieving an acceptable symptom state 2 years after primary anterior cruciate ligament reconstruction (ACLR) and to identify factors affecting its achievement, in a large cohort.

METHODS

Patients who underwent primary ACLR at Capio Artro Clinic, Stockholm, Sweden, from 2005 to 2015, were identified in our clinic registry. Patients who had completed the Knee injury and Osteoarthritis Outcome Score (KOOS) at the 2-year follow-up were included. The primary outcome was the achievement of a patient-acceptable symptom state (PASS) for each KOOS subscale. 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, the presence of medial meniscus (MM) or lateral meniscus (LM) resection or repair and the recovery of 6-month symmetrical (limb symmetry index [LSI] of ≥ 90%) isokinetic quadriceps or hamstring strength and single-leg-hop test performance were factors associated with the achievement of a PASS for each KOOS subscale.

RESULTS

A total of 2335 primary ACLRs were included. More than 60% of the patients reported a PASS on four of the five KOOS subscales. Age ≥ 30 years and an LSI of ≥ 90% for 6-month isokinetic quadriceps strength increased the odds of achieving a PASS across all KOOS subscales. Female gender reduced the odds of achieving a PASS on the Pain (OR 0.76; 95% CI 0.62-0.94; P = 0.01), activities of daily living (ADL) (OR 0.79; 95% CI 0.64-0.97; P = 0.02) and sport and recreation (OR 0.72; 95% CI 0.58-0.89; P = 0.003) subscales. The presence of an MM repair reduced the odds of achieving a PASS on the Pain (OR 0.59; 95% CI 0.36-0.96; P = 0.03) subscale. Hamstring tendon (HT) autograft rather than bone-patellar tendon-bone (BPTB) autograft showed increased odds (OR 2.02; 95% CI 1.31-3.10; P = 0.001), whereas a cartilage injury showed reduced odds (OR 0.73; 95% CI 0.55-0.97; P = 0.03) of achieving a PASS on the sport and recreation subscale. An LSI of ≥ 90% for 6-month single-leg-hop test performance increased the odds of achieving a PASS on the ADL (OR 1.37; 95% CI 1.09-1.71; P = 0.005), Sport and Recreation (OR 1.40; 95% CI 1.11-1.77; P = 0.004), and quality of life (OR 1.28; 95% CI 1.00-1.63; P = 0.04) subscales.

CONCLUSION

More than 60% of the patients reported an acceptable symptom state on four of the five KOOS subscales 2 years after primary ACLR. Age ≥ 30 years and female gender were the non-modifiable factors that consistently increased and reduced, respectively, the odds of achieving a PASS. A symmetrical 6-month isokinetic quadriceps strength and single-leg-hop test performance were the modifiable factors that consistently increased the opportunity of achieving a PASS 2 years after primary ACLR.

LEVEL OF EVIDENCE

III.

How Much Time Is Needed Between Serial "Return to Play" Assessments to Achieve Clinically Important Strength Gains in Patients Recovering From Anterior Cruciate Ligament Reconstruction?

BACKGROUND

Pass rates for return-to-play evaluations are alarmingly low for patients after anterior cruciate ligament reconstruction (ACLR). Since timing of return to play is a complicated decision, it is important that patients be given optimal time to realize meaningful improvements in strength that warrant additional testing.

PURPOSE

To (1) compare outcomes among patients assessed at different time points after ACLR, (2) determine strength gains indicative of improvements in subjective function, and (3) determine the amount of time necessary to achieve meaningful strength gains.

STUDY DESIGN

Cross-sectional/case-control study; Level of evidence, 3.

METHODS

A total of 293 patients participated in the study after ACLR (mean ± SD, 23.2 ± 10.1 years old; n = 142 female participants; 6.4 ± 0.9 months after ACLR). Participants were stratified on the month of their evaluation after ACLR: 5 to 6 months (n = 122), 6 to 7 months (n = 102), 7 to 8 months (n = 43), and 8 to 9 months (n = 26). The International Knee Documentation Committee (IKDC) subjective form and knee extensor and flexor torque and symmetry, as assessed through an isokinetic dynamometer, were compared among groups. Forty patients (20 female participants, 20.4 ± 7.1 years old) were referred for subsequent testing (2.14 ± 0.78 months after initial visit). Subjective improvement between visits was defined as a ≥9-point change of the IKDC score. Thresholds of knee extensor torque and symmetry indicative of subjective improvement and the time between assessments needed to achieve these strength improvements were determined.

RESULTS

Patients between 5 and 6 months (IKDC, 79.7; interquartile range [IQR], 70.1-88.5) had lower subjective function compared to patients between 6 and 7 months (IKDC, 83.9; IQR, 74.5-92.0; P = .019) and 8 and 9 months after ACLR (IKDC, 89.1; IQR 75.8-92.3; P = .026). Patients between 5 and 6 months (1.41 N·m/kg; IQR, 1.16-1.73 N·m/kg]) had lower knee extensor torque compared to patients 6 and 7 months (1.59 N·m/kg; IQR, 1.23-1.95 N·m/kg; P = .013) and 7 and 8 months after ACLR (1.62 N·m/kg; IQR, 1.30-1.86 N·m/kg; P = .046). Patients between 5 and 6 months (66.4%; IQR, 54.2-78.6) had lower symmetry compared to patients between 6 and 7 months (71.8%; IQR,61.1-82.9; P = .019) and 8 and 9 months afterACLR (75.2%; IQR, 66.6-87.7; P = .014). Of the 40 patients that completed follow-up assessments, an increase in knee extensor torque of 0.22 N·m/kg and symmetry of 5.75% discriminated patients that achieved subjective improvement. A period of 1.97 months between assessments discriminated those that achieved the established symmetry threshold.

CONCLUSION

Patients demonstrate increasing subjective and quadriceps function when tested at later time points from surgery; however, the observed values are low, suggesting that at 9 months patients are demonstrating deficits that may be improving. Approximately 2 months is needed to observe clinically meaningful improvements.

Normalized Hip and Knee Strength in Two Age Groups of Adolescent Female Soccer Players

Hannon, JP, Wang-Price, S, Garrison, JC, Goto, S, Bothwell, JM, and Bush, CA. Normalized hip and knee strength in two age groups of adolescent female soccer players. J Strength Cond Res XX(X): 000-000, 2019-Limb symmetry strength measures are used for clinical decision-making considering when an athlete is ready to return to sport after anterior cruciate ligament (ACL) injuries. However, changes in bilateral muscle strength occur after ACL injury resulting in potentially altered limb symmetry calculations. Adolescent female soccer players are at increased risk of sustaining ACL injuries. Published age and sex-matched strength values in this population may be of benefit to clinicians to improve clinical decision-making. The purpose of this study was to establish normative hip and knee strength data of both the dominant and nondominant limbs in adolescent female soccer players. Sixty-four female soccer players (ages 10-18) were enrolled in this study. Subjects were divided by age into 2 groups (group 1: 10-14 years; group 2: 15-18 years). Subjects underwent Biodex isokinetic strength testing at 60°·s and 180°·s to assess quadriceps and hamstring strength. Isometric hip strength (abduction and external rotation) was measured using a hand-held dynamometer. No significant differences were found between groups on either limb in regards to quadriceps or hamstring strength. No significant differences were found between groups on either limb for hip external rotation strength. Significant differences in hip abduction strength were found between groups on the dominant (group 1: 0.21 ± 0.04; group 2: 0.18 ± 0.04; p = 0.014) and nondominant (group 1: 0.21 ± 0.05; group 2: 0.18 ± 0.05; p = 0.019) limbs. The results of this study shed light on normative strength values for a high-risk injury population.

Graft Fixation and Timing of Surgery Are Predictors of Early Anterior Cruciate Ligament Revision: A Cohort Study from the Swedish and Norwegian Knee Ligament Registries Based on 18,425 Patients

The identification of surgical risk factors for early anterior cruciate ligament (ACL) revision is important when appropriate treatment for patients undergoing primary ACL reconstruction is selected. The purposes of this study were to determine the short-term ACL revision rate of patients undergoing primary ACL reconstruction and to identify surgical risk factors for ACL revision within 2 years of primary ACL reconstruction.

Unanticipated jump-landing after anterior cruciate ligament reconstruction: Does unanticipated jump-landing testing deliver additional return to sport information to traditional jump performance tests?

BACKGROUND

We aimed to delineate if unanticipated jump-landing assessments delivers complementary information to those of commonly used hop and jump tests after anterior cruciate ligament reconstruction.

METHODS

Eleven participants (5 males) performed a series of unanticipated jump-landings and traditional hop and jump performance tests (single leg hops for distance, triple crossover hops for distance and drop jumps). The number of mistrials, time to stabilization and peak ground reaction force (pGRF) at landing and jump/hop distance were measured. Pearson correlations to find potential associations between the unanticipated jump-landing-values and the traditional jump/hop performance tests were calculated twice: once for the affected and once for the unaffected legs. t-Tests for dependent samples were used to detect differences between affected and unaffected leg within each test condition.

FINDINGS

The pGRF at unanticipated landing significantly correlated to the pGRF at drop jump landing (r = 0.68) and the hopping distance after the triple crossover hops (r = 0.71, each p < .05). No other significant correlation occurred (p > .05). Hopping distance after single leg hops (mean: 110.2 cm vs. 95.5 cm) and triple crossover hops for distance (mean: 315.3 cm vs. 294.2 cm) showed significant differences between the unaffected and the reconstructed leg (p < .05). Other parameters showed no significant between-legs differences (p > .05).

INTERPRETATION

Both, the reconstructed and the contralateral leg seems to be affected. Unanticipated jump landing tasks deliver information beyond those of commonly used jump and hop tests, the thereby assessed abilities may thus be a complementary aspect of dynamic knee function than those assessed with classic tests.

Single-Leg Squat Performance and Its Relationship to Extensor Mechanism Strength After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Performance in strength and functional testing is important when considering return to sport after anterior cruciate ligament (ACL) reconstruction. Both knee extensor strength and the single-leg squat (SLS) have been used in this context.

PURPOSE

To evaluate the relationship between knee extensor strength and SLS performance after primary ACL reconstruction.

STUDY DESIGN

Cohort study (Diagnosis); Level of evidence, 3.

METHODS

A prospective cohort of 100 patients was assessed 6 and 12 months after primary ACL reconstruction with a hamstring tendon autograft. Knee extensor peak torque was measured. Three sequential SLSs were performed, and the maximum flexion angle identified from frame-by-frame video analysis was used as the measure of squat performance. A limb symmetry index (LSI) was calculated and satisfactory performance defined as ≥90%.

RESULTS

Extensor mechanism strength deficits were seen in 75% of patients at 6 months and 57% at 12 months postoperatively. Mean extensor mechanism strength showed a large improvement between 6 and 12 months (123.6 vs 147.8 N·m, respectively; P < .001; Cohen d = 1.10), and while there was also a statistically significant improvement in the mean maximum flexion angle, the change was small (66.1° vs 68.1°, respectively; P = .011; Cohen d = 0.26). There was a weak positive correlation between knee extensor strength and the SLS maximum flexion angle at 6 months (r = 0.342; P < .001) and 12 months (r = 0.245; P = .014). An SLS LSI <90% was 80% specific and 35% sensitive for extensor mechanism weakness at 6 months and 79% specific and 18% sensitive at 12 months.

CONCLUSION

Extensor mechanism strength deficits are common after ACL reconstruction but reduce between 6 and 12 months. The SLS maximum flexion angle has a weak linear relationship to knee extensor strength. SLS performance has high specificity but low sensitivity in identifying extensor mechanism strength deficits. The SLS maximum flexion angle is therefore a suboptimal surrogate test to identify extensor mechanism strength deficits as diagnosed by isokinetic dynamometric testing. However, unsatisfactory SLS performance indicates a very high chance of underlying extensor mechanism weakness.

Associations between isometric quadriceps strength characteristics, knee flexion angles, and knee extension moments during single leg step down and landing tasks after anterior cruciate ligament reconstruction

BACKGROUND

It is unclear of how peak knee extension torque and early rate of torque development outcomes are related to lower extremity loading and sagittal plane movement in activities of daily living and landing tasks despite consistent deficits after anterior cruciate ligament reconstruction. The purpose of this cross-section study is to assess the ability of quadriceps strength characteristics to predict movement patterns during a step down and single leg drop crossover hopping tasks.

METHODS

Fifty-two individuals with a unilateral history of anterior cruciate ligament reconstruction completed three trials of the step down and crossover hopping tasks on their involved limb. Participants completed three isometric knee extension contractions at 90° knee flexion with visual feedback to assess peak knee extension torque and rate of torque development during the first 0-100 ms and 100-200 ms of the contraction.

FINDINGS

Peak knee extension torque explained the greatest variance in peak knee extension moment (R² = 40.4%, p < 0.001) and knee flexion angle (R² = 46.7%, p < 0.001) during the crossover hop landing. Rate of torque development (0-100 ms) was the only predictor of knee flexion angle (R² = 19.8%, p = 0.01) at initial contact during the crossover hopping landing. Rate of torque development (100-200 ms) explained 17.6% of the variance in peak knee extension moment during the step down (p = .03).

INTERPRETATION

Peak knee extension torque and early rate of torque development outcomes demonstrate limited relationships between movement of activities of daily living and sport-specific tasks. These limitations should be considered when interpreting the results of isometric strength testing in a clinical setting.

Horizontal jumping biomechanics among elite female handball players with and without anterior cruciate ligament reconstruction: an ISU based study

Background

Handball is a strenuous body-contact team sport that places high loads on the knee joint. Anterior cruciate ligament (ACL) tear is one of the most devastating injuries that any handball player can suffer, and female athletes are at particular risk due to their intrinsic anatomical, hormonal, neuromuscular and biomechanical characteristics. The purpose of this study was to analyze the horizontal jumping biomechanics of female elite handball players with or without previous ACL reconstruction.

Methods

Twenty-one female participants (6 with previous ACL reconstruction and 15 uninjured controls) were recruited. Two horizontal hopping tasks were evaluated using inertial sensor unit (ISU)-based technology to assess jumping biomechanics through a direct mechanics-based approach.

Results

The athletes with previous ACL reconstruction demonstrated a significant (P < 0.05) reduction in the unilateral triple hop for distance compared with the healthy controls. Furthermore, during the initial propulsive phase of the unilateral cross-over hop, the control participants generated significantly (P < 0.05) higher force values in the mediolateral direction (the X axis) with their dominant limb compared with the ACL-reconstructed (ACL-R) limb of previously injured participants.

Conclusions

Three-dimensional horizontal jumping biomechanics analyses using ISU-based technologies could provide clinicians with more accurate information regarding the horizontal jumping biomechanical patterns among elite handball female athletes. Furthermore, several mechanical alterations could still be observed among those players who had undergone previous ACL reconstruction, even when several years have passed since the original ACL injury.

The effect of experimental shoulder pain on contralateral muscle force and activation

Inhibition of rotator cuff activation and force after local experimental pain has been previously shown. Clinically, strength is often indexed to the uninvolved side in order to quantify deficits during injury and recovery. This study assessed the effect of experimental subacromial pain on contralateral shoulder external rotation (ER) force and activation. We hypothesized that subacromial pain would not affect contralateral shoulder external rotation force and voluntary activation (VA) of the contralateral infraspinatus because we believe that the effects of acute experimental pain will largely exert an ipsilateral, spinal segmental effect. Twenty healthy adults were tested. External rotation force and VA were tested while participants performed maximum voluntary isometric contractions of shoulder external rotation, during which a brief electrical stimulus was applied to the infraspinatus muscle at an intensity that maximized external rotation force. To elicit pain, 1.5 ml of 5% hypertonic saline was injected into the contralateral subacromial space. Mean (SD) pain immediately after injection was 6.3/10 (0.85) resulting in a 7.6% decline in contralateral external rotation force (p < .01) and 3.3% decline in infraspinatus muscle VA (p = .48). A subset of participants (n = 9) showed a more substantial decline in both force (15.4%; p < .000001; d = -3.53) and VA (8.7%; p = .045; d = -0.98). Experimental shoulder pain had a modest effect on contralateral ER force and VA in a subset of participants; therefore, it may be important to index or compare strength bilaterally throughout rehabilitation to capture this bilateral effect as pain resolves.

Failure risks in anatomic single-bundle anterior cruciate ligament reconstruction via the outside-in tunnel technique using a hamstring autograft

Purpose

To retrospectively evaluate the failure risk factors in anatomic single-bundle anterior cruciate ligament (ACL) reconstruction via outside-in tunnel technique using a hamstring autograft, and investigate the relationship between each risk factor.

Methods

The patients who underwent the ACL reconstruction with a minimum 1-year follow-up were included. We divided the patients into two groups - those who experienced graft failure (the failure group) and those who did not experience graft failure (the no failure group) - and compared their age, height, weight, sports activity level, graft size, and muscle strength. We defined graft failure as patients who underwent revision ACL reconstruction or had a second injurious ACL episode and those with a graft grade of C or D based on the International Knee Documentation Committee score.

Results

The study included 232 patients (101 male, 131 female; mean age at operation was 26.1 ± 11.9 years). The failure rate was 11.6% (failure group: 27 patients; no failure group: 205 patients). The patients in the failure group were younger and had higher sports activity level than those in the no failure group. (p < 0.001 and p < 0.001, respectively). Patient body weight in the failure group was lower than that in the no failure group (p = 0.047). Regarding the graft size of the tibial side, the failure group had smaller graft sizes than the no failure group (p = 0.030). With respect to muscle strength, quadriceps strength 6 months after surgery in the failure group was stronger than that in the no failure group (p = 0.001). In addition, the hamstring/quadriceps strength (H/Q) ratios 3 and 6 months after surgery were lower in the failure group than that in the no failure group (p = 0.041 and p = 0.001, respectively). There was an association between the age and the body weight, between the body weight and the graft size of the tibial side, and between lower age and high sports activity. Moreover, the high quadriceps strength at 6 months and the low H/Q ratio at 3 months were related to the low H/Q ratio at 6 months.

Conclusion

Young age, high activity sports level, low body weight, small graft diameter of the tibial side, high quadriceps strength at 6 months, and low H/Q ratio at 3 and 6 months can be failure risk factors in anatomic single-bundle ACL reconstruction via the outside-in tunnel technique using a hamstring autograft.

ACL Reconstruction Using Autologous Hamstrings Augmented With the Ligament Augmentation and Reconstruction System Provides Good Clinical Scores, High Levels of Satisfaction and Return to Sport, and a Low Retear Rate at 2 Years

Background:

There are a number of surgical methods for undertaking anterior cruciate ligament (ACL) reconstruction (ACLR), although relatively high rates of ipsilateral retears and contralateral tears exist, with only 65% of patients returning to their preinjury level of sport. ACLR techniques adopting synthetic augmentation have been proposed in an attempt to improve clinical outcomes and reduce reinjury rates.

Purpose:

To determine the efficacy of ACLR using autologous hamstrings augmented with the Ligament Augmentation and Reconstruction System (LARS).

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 65 patients were prospectively treated with arthroscopically assisted single-bundle ACLR using hamstrings augmented with the LARS, of whom 50 were available for 1- and 2-year reviews. Patient-reported outcome measures (PROMs), KT-1000 arthrometer testing, knee range of motion, peak isokinetic knee strength testing, and a battery of 4 hop tests were employed. Limb symmetry indices (LSIs) were calculated. Analysis of variance was used to evaluate differences over time and between limbs. Data on return to the preinjury level of sport, retears, and reoperations were collected.

Results:

High PROM scores were demonstrated at 1 and 2 years. Before the injury, 47 patients (94%) were actively participating in level 1 or 2 sports, with 38 (76%) and 43 (86%) patients having returned at 1 and 2 years, respectively. Normal (<3 mm; 90%) or nearly normal (3-5 mm; 10%) KT-1000 arthrometer side-to-side differences were observed at 2 years. Apart from knee flexion (P < .0001), extension (P = .001), and the 6-m timed hop (P = .039), there were no between-limb differences at 1 year, and there were no differences on any objective measures at 2 years (all P > .05). Mean LSIs across all measures were ≥90%. At 2 years, 84% to 90% of patients were ≥90% on the hop tests, with 72% and 76% of patients having ≥90% for extension and flexion strength, respectively. Two reoperations were undertaken for meniscal tears (7 and 8.5 months), 1 patient (2%) suffered a retear at 7 months, and 2 patients (3%) suffered a contralateral tear (8 and 12 months).

Conclusion:

This augmented ACLR technique demonstrated good clinical scores, a high rate of return to sport, and low rates of secondary ruptures and contralateral ACL tears at 2 years. Some caution should be noted in interpreting these results, as 15 of 65 patients (23%) were not included in the 2-year follow-up.

Lower extremity kinematic analysis in male athletes with unilateral anterior cruciate reconstruction in a jump-landing task and its association with return to sport criteria

Background

Return to sport (RTS) criteria are widely being used to identify anterior cruciate ligament reconstructed (ACLR) athletes ready to return to sportive activity and reduce risk of ACL re-injury. However, studies show a high rate of ACL re-injury in athletes who passed RTS criteria. This indicates that the current RTS criteria might not be sufficient to determine return to sport time in ACLR athletes. Previous studies have reported a close association between altered lower limb kinematics and ACL re-injury. However, it is not clear how lower extremity kinematics differs between ACLR athletes who passed the RTS-criteria and who failed. This study compared lower extremity kinematics in a jump-landing task between ACLR athletes who passed the RTS criteria (Limb symmetry in hop tests, quadriceps strength and questionnaires) to those who failed and to the healthy individuals.

Methods

Participants were 27 male football players with unilateral ACLR including 14 who passed -RTS criteria and 13 failed, and 15 healthy football players. A 3D motion capture system recorded participants’ lower extremity motion while performing 10 trials of a bilateral jump-landing task. Hip, knee and ankle angular motion were examined at initial contact. Two-way mixed analysis of variances (2 limbs × 3 groups) and Bonferroni post-hoc tests were performed to compare the joint angles between the limbs and groups.

Results

lower hip abduction angle was found in the failed (involved limb 4.1 ° ± 4.2) and passed RTS (involved limb 6.8° ± 3.3) groups compared to the healthy group (non-dominant limb 10.7° ± 3.7). Ankle inversion in the failed RTS (0.4° ± 4.9) group was significantly lower than both passed RTS (4.8° ± 4.8, p = 0.05) and healthy (8.2° ± 8.1, p < 0.001) groups. There were no significant differences between the groups in knee kinematics.

Conclusions

Our findings indicate reduced hip abduction during initial contact phase of landing in athletes returned to sport. Reduced hip abduction during the complex multiplanar movement of jump-landing is a risk factor for ACL re-injury. Current RTS criteria may not be sufficient to identify ACLR athletes at high risk of re-injury. The kinematic analysis in conjunction with current RTS criteria can provide additional insight into the return to sport decision making.

Graft Diameter and Graft Type as Predictors of Anterior Cruciate Ligament Revision: A Cohort Study Including 18,425 Patients from the Swedish and Norwegian National Knee Ligament Registries

BACKGROUND

It is important to investigate and compare graft diameters as well as graft types to identify risk factors for revision after an anterior cruciate ligament (ACL) reconstruction. We performed the current study in order to analyze the early ACL revision rate among patients treated with hamstring tendon (HT) autografts or patellar tendon (PT) autografts of different diameters. Our hypothesis was that an increase in both HT and PT autograft diameters would reduce the risk of early ACL revision.

METHODS

This retrospective study was based on prospectively collected data from the national knee ligament registries of Norway and Sweden and included patients who underwent primary ACL reconstruction during the period of 2004 through 2014. The primary end point was the 2-year incidence of ACL revision. The impact of graft type and diameter on the incidence of revision surgery was reported as relative risks (RRs) with 95% confidence intervals (CIs), estimated by using generalized linear models with a binomial distribution and log-link function.

RESULTS

Of 58,692 patients identified, a total of 18,425 patients were included in this study. The 2-year rate of ACL revision was 2.10% (PT autografts, 2.63%; HT autografts, 2.08%; RR = 0.93 [95% CI = 0.60 to 1.45]). There was an increased risk of ACL revision among patients treated with HT autografts with a diameter of <8 mm compared with larger HT autografts (RR = 1.25 [95% CI = 1.01 to 1.57]). Patients treated with HT autografts with a diameter of ≥9.0 mm or ≥10.0 mm had a reduced risk of early ACL revision compared with patients treated with PT autografts.

CONCLUSIONS

Patients treated with larger-diameter HT autografts had a lower risk of early ACL revision compared with those treated with HT autografts of <8 mm. Patients treated with HT autografts of ≥9 or ≥10 mm had a reduced risk of early ACL revision compared with patients treated with PT autografts.

LEVEL OF EVIDENCE

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

Test-retest reliability and discriminative ability of forward, medial and rotational single-leg hop tests

BACKGROUND

Single-leg hop tests are commonly performed in the forward direction to evaluate functional performance. However, athletes move in multiple directions during pivoting sports. The first aim of this study was to examine test-retest reliability of single-leg hop tests in the forward, medial and rotational direction in non-injured athletes. Second, the discriminative ability to detect leg asymmetries with these hop tests in anterior cruciate ligament (ACL) reconstructed athletes was determined.

METHODS

Sixteen recreational non-injured participants (eight females, eight males; 22.4 ± 1.9 years) were tested twice (one-week interval) and performed the single hop for distance (SH), triple hop for distance (TH), medial side triple hop for distance (MSTH) and 90° medial rotation hop for distance (MRH). Intraclass correlation coefficients (ICCs), standard errors of measurement (SEM) and smallest detectable differences (SDD) were calculated. Discriminative ability was determined in 32 ACL-reconstructed participants (four females, 28 males; 24.4 ± 4.6 years; six months postoperative) who performed the same hop tests once.

RESULTS

The ICCs ranged between 0.93 and 0.98. The SEM and SDD were respectively 2.6-4.1% and 7.2-11.3% of the mean hop distance of the group. The proportion (%) of ACL-reconstructed participants passing the ≥90% limb symmetry cut-off was 62.5 (SH), 59.4 (TH), 40.6 (MSTH) and 46.9 (MRH).

CONCLUSION

Excellent test-retest reliability of forward, medial and rotational hop tests was found. This allows clinicians to make informed interpretations of changes in hop test distances when retesting athletes. Medial and rotational hop tests are more likely to show limb asymmetries in ACL-reconstructed participants compared to forward hop tests.

Partial medial meniscectomy leads to altered walking mechanics two years after anterior cruciate ligament reconstruction: Meniscal repair does not

BACKGROUND

Partial meniscectomy dramatically increases the risk for post-traumatic, tibiofemoral osteoarthritis after anterior cruciate ligament reconstruction (ACLR). Concomitant medial meniscus surgery influences walking biomechanics (e.g., medial tibiofemoral joint loading) early after ACLR; whether medial meniscus surgery continues to influence walking biomechanics two years after ACLR is unknown.

RESEARCH QUESTION

Does medial meniscus treatment at the time of ACLR influence walking biomechanics two years after surgery?

METHODS

This is a secondary analysis of prospectively collected data from a clinical trial (NCT01773317). Fifty-six athletes (age 24 ± 8 years) with operative reports, two-year biomechanical analyses, and no second injury prior to two-year testing participated after primary ACLR. Participants were classified by concomitant medial meniscal status: no medial meniscus involvement (n = 36), partial medial meniscectomy (n = 9), and medial meniscus repair (n = 11). Participants underwent biomechanical analyses during over-ground walking including surface electromyography; a validated musculoskeletal model estimated medial compartment tibiofemoral contact forces. Gait variables were analyzed using 3 × 2 ANOVAs with group (medial meniscus treatment) and limb (involved versus uninvolved) comparisons.

RESULTS

There was a main effect of group (p = .039) for peak knee flexion angle (PKFA). Participants after partial medial meniscectomy walked with clinically meaningfully smaller PKFAs in both the involved and uninvolved limbs compared to the no medial meniscus involvement group (group mean difference [95%CI]; involved: -4.9°[-8.7°, -1.0°], p = .015; uninvolved: -3.9°[-7.6°, -0.3°], p = .035) and medial meniscus repair group (involved: -5.2°[-9.9°, -0.6°], p = .029; uninvolved: -4.7°[-9.0°, -0.3°], p = .038). The partial medial meniscectomy group walked with higher involved versus uninvolved limb medial tibiofemoral contact forces (0.45 body weights, 95% CI: -0.01, 0.91 BW, p = 0.053) and truncated sagittal plane knee excursions, which were not present in the other two groups.

SIGNIFICANCE

Aberrant gait biomechanics may concentrate high forces in the antero-medial tibiofemoral cartilage among patients two years after ACLR plus partial medial meniscectomy, perhaps explaining the higher osteoarthritis rates and offering an opportunity for targeted interventions.

LEVEL OF EVIDENCE

Level III.

[Research progress of double-bundle anterior cruciate ligament reconstruction in adolescents]

OBJECTIVE

To review the advances in double-bundle anterior cruciate ligament (ACL) reconstruction in adolescents at home and abroad.

METHODS

Recent literature about double-bundle ACL reconstruction in adolescents at home and abroad was extensively consulted, and the relationship between bone canal and epiphyseal plate, clinical verification of surgical safety, and clinical effectiveness of double-bundle ACL reconstruction in adolescents were summarized and analyzed.

RESULTS

Double-bundle ACL reconstruction has certain advantages in clinical stability and re-rupture rate when compared with single-bundle ACL reconstruction in adolescents, and there is no significant difference in safety between them.

CONCLUSION

Double-bundle ACL reconstruction in adolescents can achieve lower re-rupture rate and better stability when compared with single-bundle reconstruction. However, the sample size of clinical research is too small, and the follow-up time is too short, so the effectiveness needs to be continuously observed.

Thresholds in the Relationship of Quadriceps Strength With Functional Limitations in Women With Knee Osteoarthritis

OBJECTIVE

To investigate thresholds of strength below which individuals with knee osteoarthritis (OA) may have more difficulty carrying out physical functions of daily life. Individuals below such thresholds might benefit more from strengthening interventions than those with greater strength.

METHODS

We studied individuals with symptomatic OA at baseline in the Multicenter Osteoarthritis Study who had knee extensor strength measured isokinetically at 60º/second. Participants underwent a 20-meter walk test and a sit-to-stand test and answered questions from the Western Ontario and McMaster Universities Osteoarthritis Index. Physical function results were plotted against measures of quadriceps strength (Nm) (and as strength:body weight) for the worst knee. Loess technique was used to examine inflection points. Nonlinear relationships were examined in piecewise linear regression models. Differences were tested using linear and logistic regression models.

RESULTS

The study had 834 participants (65.8% women). The mean ± SD age of the participants was 62.9 ± 7.9 years. In women, there were thresholds of strength below which the slope of strength versus function was steeper: walking speed (<58 Nm), chair stand time (<32 Nm), and the McMaster Universities Osteoarthritis Index functions of rising from a chair and getting on/off the toilet (<38 Nm). We found no thresholds in men. Loess analyses using strength:weight showed similar results.

CONCLUSION

In individuals with symptomatic knee OA, thresholds in the strength function relationship may help identify individuals, especially women, at the brink of disability insofar as strength and capacity for daily tasks. In those with low strength, small increments in strength may be associated with improvement in function and greater ease with common daily life, emphasizing the importance of preventing loss of strength.

Case Study: Muscle Atrophy, Hypertrophy, and Energy Expenditure of a Premier League Soccer Player During Rehabilitation From Anterior Cruciate Ligament Injury

Maintaining muscle mass and function during rehabilitation from anterior cruciate ligament injury is complicated by the challenge of accurately prescribing daily energy intakes aligned to energy expenditure. Accordingly, we present a 38-week case study characterizing whole body and regional rates of muscle atrophy and hypertrophy (as inferred by assessments of fat-free mass from dual-energy X-ray absorptiometry) in a professional male soccer player from the English Premier League. In addition, in Week 6, we also quantified energy intake (via the remote food photographic method) and energy expenditure using the doubly labeled water method. Mean daily energy intake (CHO: 1.9-3.2, protein: 1.7-3.3, and fat: 1.4-2.7 g/kg) and energy expenditure were 2,765 ± 474 and 3,178 kcal/day, respectively. In accordance with an apparent energy deficit, total body mass decreased by 1.9 kg during Weeks 1-6 where fat-free mass loss in the injured and noninjured limb was 0.9 and 0.6 kg, respectively, yet, trunk fat-free mass increased by 0.7 kg. In Weeks 7-28, the athlete was advised to increase daily CHO intake (4-6 g/kg) to facilitate an increased daily energy intake. Throughout this period, total body mass increased by 3.6 kg (attributable to a 2.9 and 0.7 kg increase in fat free and fat mass, respectively). Our data suggest it may be advantageous to avoid excessive reductions in energy intake during the initial 6-8 weeks post anterior cruciate ligament surgery so as to limit muscle atrophy.

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.

Neurological structures and mediators of pain sensation in anterior cruciate ligament reconstruction

Anterior cruciate ligament (ACL) tears is a devastating injury and one of the most common knee injuries experienced by athletes in the United States. Although patients reach maximal subjective improvement by one-year following ACL reconstruction, many patients often experience moderate to severe post-operative pain. Opioids, intra-articular injections, and regional anesthesia have been previously implemented to mediate post-operative pain. However, chronic opioid usage has become an epidemic in the United States. Alternative analgesic modalities, such as nerve blocks, have been implemented in clinical practice to provide adequate pain relief and minimize opioid usage. Periarticular injections targeted towards local neurological structures performed concomitantly with nerve blocks provides superior pain relief and satisfaction than isolated nerve blocks. Therefore, it is imperative for physicians to understand local neurological anatomy around the knee joint in order to provide adequate analgesia while minimizing opioid consumption. This purpose of this investigation is to summarize (1) neurogenic origins of pain generators and mediators in sites affected by ACL reconstruction and autograft harvest sites and (2) analgesia utilized in ACL reconstruction.

Psychosocial Barriers After Anterior Cruciate Ligament Reconstruction: A Clinical Review of Factors Influencing Postoperative Success

CONTEXT

Psychosocial factors arising after anterior cruciate ligament (ACL) injury may have a direct influence on an individual's decision to return to sport after ACL reconstruction (ACLR). While there is ample evidence to suggest that deficits in quadriceps strength, neuromuscular control, and clinical functional tasks exist after ACLR, the root and contribution of psychological dysfunction to an individual's success or return to sport after ACLR is still largely uncertain and unexplored. Given the discrepancy between successful functional outcomes and the percentage of athletes who return to sport, it is important to thoroughly address underlying factors, aside from physical function, that may be contributing to these lower return rates.

EVIDENCE ACQUISITION

Articles that reported on return to sport, psychological factors, and psychosocial factors after ACLR were collected from peer-reviewed sources available on Medline (1998 through August 2018). Search terms included the following: anterior cruciate ligament OR ACL AND return-to-sport OR return-to-activity, anterior cruciate ligament OR ACL AND psychological OR psychosocial OR biopsychosocial OR fear OR kinesiophobia OR self-efficacy, return-to-activity AND psychological OR psychosocial.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 5.

RESULTS

Psychosocial factors relative to injury are important components of the rehabilitation process. To fully understand how psychosocial factors potentially influence return to sport, an athlete's emotions, experiences, and perceptions during the rehabilitation process must be acknowledged and taken into consideration.

CONCLUSION

Acknowledgment of these psychosocial factors allows clinicians to have a better understanding of readiness to return to sport from a psychological perspective. Merging of the current ACLR rehabilitation protocols with knowledge related to psychosocial factors creates a more dynamic, comprehensive approach in creating a positive and successful rehabilitation environment, which may help improve return-to-sport rates in individuals after ACLR.

Effectiveness of a home-based re-injury prevention program on motor control, return to sport and recurrence rates after anterior cruciate ligament reconstruction: study protocol for a multicenter, single-blind, randomized controlled trial (PReP)

Background

Although anterior cruciate ligament (ACL) tear-prevention programs may be effective in the (secondary) prevention of a subsequent ACL injury, little is known, yet, on their effectiveness and feasibility. This study assesses the effects and implementation capacity of a secondary preventive motor-control training (the Stop-X program) after ACL reconstruction.

Methods and design

A multicenter, single-blind, randomized controlled, prospective, superiority, two-arm design is adopted. Subsequent patients (18–35 years) with primary arthroscopic unilateral ACL reconstruction with autologous hamstring graft are enrolled. Postoperative guideline rehabilitation plus Classic follow-up treatment and guideline rehabilitation plus the Stop-X intervention will be compared. The onset of the Stop-X program as part of the postoperative follow-up treatment is individualized and function based. The participants must be released for the training components. The endpoint is the unrestricted return to sport (RTS) decision. Before (where applicable) reconstruction and after the clearance for the intervention (aimed at 4–8 months post surgery) until the unrestricted RTS decision (but at least until 12 months post surgery), all outcomes will be assessed once a month. Each participant is consequently measured at least five times to a maximum of 12 times. Twelve, 18 and 24 months after the surgery, follow-up-measurements and recurrence monitoring will follow. The primary outcome assessement (normalized knee-separation distance at the Drop Jump Screening Test (DJST)) is followed by the functional secondary outcomes assessements. The latter consist of quality assessments during simple (combined) balance side, balance front and single-leg hops for distance. All hop/jump tests are self-administered and filmed from the frontal view (3-m distance). All videos are transferred using safe big content transfer and subsequently (and blinded) expertly video-rated. Secondary outcomes are questionnaires on patient-reported knee function, kinesiophobia, RTS after ACL injury and training/therapy volume (frequency – intensity – type and time). All questionnaires are completed online using the participants’ pseudonym only.

Group allocation is executed randomly. The training intervention (Stop-X arm) consists of self-administered home-based exercises. The exercises are step-wise graduated and follow wound healing and functional restoration criteria. The training frequency for both arms is scheduled to be three times per week, each time for a 30 min duration. The program follows current (secondary) prevention guidelines.

Repeated measurements gain-score analyses using analyses of (co-)variance are performed for all outcomes.

Trial registration

German Clinical Trials Register, identification number DRKS00015313. Registered on 1 October 2018.

Similar risk of ACL graft revision for alpine skiers, football and handball players: the graft revision rate is influenced by age and graft choice

Objectives

The risk of graft revision following ACL reconstruction may depend on the sport type the individuals are engaged in. The purpose of this study was to report the ACL graft revision rate in alpine skiers, football and handball players.

Materials and methods

Primary ACL reconstructions and graft revision data from 2004 to December 2016 were obtained from the Norwegian Cruciate Ligament Registry. The graft survival rates were calculated for individuals in each of the three sport types, for bone patellar tendon bone (BPTB) and hamstring tendons (HT) grafts separately, and related to age at primary operation and sex.

Results

A total of 711 grafts in 14 201 primary ACL reconstructions were revised (5.0%) after median 6 years, 3.8% in alpine skiers, 5.0% in soccer and 6.1% in handball players (p<0.001). Adjusted Cox regression showed similar ACL graft survival rates in the three groups. The HR for graft revision was 5 times higher for individuals aged ≤18 years than for those aged ≥35 years (p<0.001). The corresponding HR for graft type was 1.8 times higher for HT than for BPTB grafts (p<0.001), but 2.8 times higher for individuals aged ≤18 years (p<0.001). The 12 years survival of BPTB grafts was 96% compared with 93% for HT grafts (p <0.001).

Conclusion

The revision rate for ACL grafts was similar among alpine skiers, football and handball players, and the results support the use of BPTB grafts in young athletes with closed growth zones in the knee.

Study design

Cohort study; level of evidence, 2.

The relationships between kinesiophobia and clinical outcomes after ACL reconstruction differ by self-reported physical activity engagement

OBJECTIVES

To investigate whether relationships between kinesiophobia, lower extremity function, and patient-reported function differ by self-reported physical activity engagement after ACL reconstruction (ACLR).

DESIGN

Cross-sectional.

SETTING

Laboratory.

PARTICIPANTS

Seventy-seven patients with a primary, unilateral ACLR.

MAIN OUTCOME MEASURES

Kinesiophobia (TSK-17) was the primary outcome. Lower extremity function included quadriceps and hamstrings strength, fatigue, and hop performance. Patient-reported function included regional function (IKDC, KOOS subscales) and physical activity engagement (Godin Leisure-Time Exercise). Patients were evaluated together, then stratified by LOW and HIGH physical activity. Correlations and multiple regression analyses identified relationships between kinesiophobia and outcome measures.

RESULTS

Greater kinesiophobia was associated with lesser hamstrings strength, hop performance, and patient-reported function. Greater hamstrings fatigue and lesser KOOS_ADL explained greater kinesiophobia in patients reporting LOW physical activity. Lesser triple hop symmetry, crossover hop distance, and IKDC explained greater kinesiophobia in patients reporting HIGH physical activity.

CONCLUSIONS

Greater kinesiophobia associated with worse outcomes after ACLR. Relationships differed by self-reported physical activity engagement. Interventions that improve the ability to perform knee-related activities of daily living may be appropriate to minimize the impact of fear in less active patients, while those targeting hop performance and knee-related sport activities may be better suited for more active patients.

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).

Gait Mechanics in Women of the ACL-SPORTS Randomized Control Trial: Interlimb Symmetry Improves Over Time Regardless of Treatment Group

Women after anterior cruciate ligament (ACL) injury and ACL reconstruction (ACLR) are more likely than men to exhibit asymmetric movement patterns, which are associated with post-traumatic osteoarthritis. We developed the ACL specialized post-operative return-to-sports (ACL-SPORTS) randomized control trial to test the effect of strength, agility, plyometric, and secondary prevention (SAPP) training with and without perturbation training (SAPP + PERT) on gait mechanics in women after ACLR. We hypothesized that movement symmetry would improve over time across both groups but more so among the SAPP + PERT group. Thirty-nine female athletes 3-9 months after primary ACLR were randomized to SAPP or SAPP + PERT training. Biomechanical testing during overground walking occurred before (Pre-training) and after (Post-training) training and one and 2 years post-operatively. Hip and knee kinematic and kinetic variables were compared using repeated measures analysis of variance with Bonferroni corrections for post hoc comparisons (α = 0.05). There was a time by limb interaction effect (p = 0.028) for peak knee flexion angle (PKFA), the primary outcome which powered the study, characterized by smaller PKFA in the involved compared to uninvolved limbs across treatment groups at Pre-training, Post-training, and 1 year, but not 2 years. Similar findings occurred across sagittal plane knee excursions and kinetics and hip extension excursion at midstance. There were no meaningful interactions involving group. Neither SAPP nor SAPP + PERT training improved walking mechanics, which persisted 1 but not 2 years after ACLR. Statement of clinical significance: Asymmetrical movement patterns persisted long after participants achieved symmetrical strength and functional performance, suggesting more time is needed to recover fully after ACLR. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1743-1753, 2019.

Superior 2-Year Functional Outcomes Among Young Female Athletes After ACL Reconstruction in 10 Return-to-Sport Training Sessions: Comparison of ACL-SPORTS Randomized Controlled Trial With Delaware-Oslo and MOON Cohorts

BACKGROUND

Outcomes after anterior cruciate ligament reconstruction (ACLR) are not uniformly good and are worse among young female athletes. Developing better rehabilitation and return-to-sport training programs and evaluating their outcomes are essential.

PURPOSE

(1) Test the effect of strength, agility, plyometric, and secondary prevention (SAPP) exercises with and without perturbation training (SAPP + PERT) on strength, hops, function, activity levels, and return-to-sport rates in young female athletes 1 and 2 years after ACLR and (2) compare 2-year functional outcomes and activity levels among young female athletes in the Anterior Cruciate Ligament Specialized Post-Operative Return-to-Sports (ACL-SPORTS) trial to homogeneous cohorts who completed criterion-based postoperative rehabilitation alone (Multicenter Orthopaedic Outcomes Network [MOON]) and in combination with extended preoperative rehabilitation (Delaware-Oslo).

STUDY DESIGN

Randomized controlled trial, Level of evidence, 1; and cohort study, Level of evidence, 3.

METHODS

A total of 40 level 1 and level 2 female athletes were enrolled after postoperative impairment resolution 3 to 9 months after primary ACLR. Participants were randomized to 10 SAPP or SAPP + PERT sessions and were tested 1 and 2 years after ACLR on quadriceps strength, hop tests, functional outcomes, and return-to-sport rates. Participants were then compared with homogeneous cohorts of young (<25 years) female athletes who completed criterion-based postoperative rehabilitation alone (MOON) and in combination with extended preoperative rehabilitation (Delaware-Oslo) on 2-year functional outcomes.

RESULTS

No significant or meaningful differences were found between SAPP and SAPP + PERT, so groups were collapsed for comparison with the other cohorts. At 2-year follow-up, ACL-SPORTS had the highest scores (P < .01) on the Marx activity rating scale (ACL-SPORTS, 13.5 ± 3.3; Delaware-Oslo, 12.5 ± 2.7; MOON, 10.6 ± 5.1); International Knee Documentation Committee Subjective Knee Evaluation Form (96 ± 7, 92 ± 9, and 84 ± 14, respectively); and Knee injury and Osteoarthritis Outcome Score (KOOS) subscales for Pain (98 ± 4, 94 ± 9, and 90 ± 10, respectively), Symptoms (94 ± 6, 90 ± 9, and 83 ± 14, respectively), Activities of Daily Living (100 ± 1, 99 ± 4, and 96 ± 7, respectively), Sports and Recreation (94 ± 8, 86 ± 15, and 82 ± 17, respectively), and Quality of Life (89 ± 14, 78 ± 18, and 76 ± 19, respectively). The Patient Acceptable Symptom State threshold on the KOOS-Sports and Recreation was achieved by 100% of the ACL-SPORTS cohort compared with 90% of Delaware-Oslo and 78% of MOON (P = .011).

CONCLUSION

Although perturbation training provided no added benefit, 10 sessions of return-to-sport training, compared with criterion-based postoperative rehabilitation alone, yielded statistically significant and clinically meaningfully higher 2-year functional outcomes among young, high-level female athletes after ACLR.

REGISTRATION

NCT01773317 (ClinicalTrials.gov identifier).

No shortage of disagreement between biomechanical and clinical hop symmetry after anterior cruciate ligament reconstruction

BACKGROUND

Evaluating average performance on functional hop tasks can potentially overestimate physical function, as it masks variability present within individual trials and may lead to clinician oversight regarding the overall movement quality. The purpose was to evaluate the trial-by-trial agreement between hop-distance symmetry and knee biomechanics (knee flexion angle, knee extension moment) to reveal the full extent of agreement between these measures.

METHODS

Sixteen individuals with primary, unilateral anterior cruciate ligament reconstruction participated (age: 22(2) y; height: 1.71(0.11) m; mass: 68.94(13.06) kg; gender: 8 males, 8 females; years' post-surgery:4(3) y) in a cross-sectional study. Knee kinematics and kinetics were measured using 3D motion analysis and hop distance was collected during the triple hop for distance. Individual limb difference values for individual hop trials were calculated and values for each trial were dichotomized as pass/fail based on achieving a limb difference of <10%. Cohen's Kappa and confirmatory McNemar's test were performed to determine the level of agreement between measures of physical and biomechanical function between trials.

FINDINGS

No agreement between triple hop and peak knee flexion angle symmetry (κ = 0.033, p = 0.387) and peak internal knee extension moment (κ = 0.022, p = 0.475) were found. McNemar tests confirmed no agreement between hop-distance %LD and knee flexion angle/knee extension moment %LD (p = 0.000).

INTERPRETATION

These findings suggest that while individuals after ACLR may on average achieve symmetrical hop-distance, they may not necessarily pass subsequent functional tasks. Further, individual trial-by-trial analyses may provide insight into an individual's true physical capability compared to simply evaluating the average, which may overestimate physical function or mask altered movement strategies.