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

Hip external rotation strength predicts hop performance after anterior cruciate ligament reconstruction

PURPOSE

Quadriceps strength and single-leg hop performance are commonly evaluated prior to return to sport after anterior cruciate ligament reconstruction (ACLR). However, few studies have documented potential hip strength deficits after ACLR, or ascertained the relative contribution of quadriceps and hip strength to hop performance.

METHODS

Patients cleared for return to sports drills after ACLR were compared to a control group. Participants' peak isometric knee extension, hip abduction, hip extension, and hip external rotation (HER) strength were measured. Participants also performed single-leg hops, timed hops, triple hops, and crossover hops. Between-limb comparisons for the ACLR to control limb and the non-operative limb were made using independent two-sample and paired sample t tests. Pearson's correlations and stepwise multiple linear regression were used to determine the relationships and predictive ability of limb strength, graft type, sex, and limb dominance to hop performance.

RESULTS

Sixty-five subjects, 20 ACLR [11F, age 22.8 (15-45) years, 8.3 ± 2 months post-op, mass 70.47 ± 12.95 kg, height 1.71 ± 0.08 m, Tegner 5.5 (3-9)] and 45 controls [22F, age 25.8 (15-45) years, mass 74.0 ± 15.2 kg, height 1.74 ± 0.1 m, Tegner 6 (3-7)], were tested. Knee extension (4.4 ± 1.5 vs 5.4 ± 1.8 N/kg, p = 0.02), HER (1.4 ± 0.4 vs 1.7 ± 0.5 N/kg, p = 0.04), single-leg hop (146 ± 37 vs 182 ± 38% limb length, p < 0.01), triple hop (417 ± 106 vs 519 ± 102% limb length, p < 0.01), timed hop (3.3 ± 2.0 vs 2.3 ± 0.6 s, p < 0.01), and crossover hop (364 ± 107 vs 446 ± 123% limb length, p = 0.01) were significantly impaired in the operative versus control subject limbs. Similar deficits existed between the operative and non-operative limbs. Knee extension and HER strength were significantly correlated with each of the hop tests, but only HER significantly predicted hop performance.

CONCLUSIONS

After ACLR, patients have persistent HER strength, knee extension strength, and hop test deficits in the operative limb compared to the control and non-operative limbs, even after starting sport-specific drills. Importantly, HER strength independently predicted hop performance. Based on these findings, to resolve between-limb deficits in strength and hop performance clinicians should include HER strengthening exercises in post-operative rehabilitation.

LEVEL OF EVIDENCE

Prognostic Study, Level II.

Clinical Outcomes, Return to Sports, and Patient Satisfaction After Anterior Cruciate Ligament Reconstruction in Young and Middle-Aged Patients in an Asian Population-A 2-Year Follow-up Study

PURPOSE

To compare the clinical outcomes of arthroscopic anterior cruciate ligament (ACL) reconstruction in young and middle-aged Asians.

METHODS

A retrospective study was performed using prospectively collected data from a tertiary institution ACL registry. All Asian patients with ACL tears who underwent primary arthroscopic ACL reconstruction by a single surgeon between 2008 and 2014, with minimum 2-year follow-up, were included. Patients with previous knee surgery or multiligamentous knee injuries were excluded. Two groups were formed: young patients (YP) (age <30) and middle-aged patients (MP) (age >40). They were compared preoperatively and 6 months, 1 year, and 2 years postoperatively for demographics, knee range of motion, anterior laxity, Tegner level, Lysholm and International Knee Documentation Committee grade, ability to return to preinjury level of activity, and patient satisfaction.

RESULTS

YP (n = 84) and MP (n = 22) had differences in mean age (YP = 23.1 years, range 18-29 years; MP = 46.4 years, range 41-59 years, P < .001), preinjury Tegner level (YP = 7.4, MP = 6.4, P = .005), and preoperative Lysholm scores (YP = 65.3, MP = 53.0, P = .034). The incidence of meniscal and chondral injuries was similar. Two years postoperatively, both groups had comparable knee range of motion and anterior laxity. The Tegner score was different (YP = 6.3, MP = 5.2, P = .028), but the proportion of patients returning to preinjury Tegner level (YP = 45.2%, MP = 46.9%, P = .812), Lysholm scores (YP = 92.5, MP = 93.8, P = .794), proportion of patients with knees rated International Knee Documentation Committee A/B (YP = 77.4%, MP = 81.8%, P = .777), and satisfaction levels (YP = 98.5%, MP = 94.1%, P = .370) were similar. There were no graft ruptures or reoperations.

CONCLUSIONS

In an Asian, predominantly male population, the clinical outcomes of arthroscopic ACL reconstruction in YP and MP are equally good at 2-year follow-up. MP can benefit as much as younger patients from ACL reconstruction in terms of restoration of knee function and return to preinjury activity level, are equally satisfied with outcomes, and should not be excluded from surgery on the basis of age alone.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

2018 International Olympic Committee Consensus Statement on Prevention, Diagnosis, and Management of Pediatric Anterior Cruciate Ligament Injuries

In October 2017, the International Olympic Committee hosted an international expert group of physical therapists and orthopaedic surgeons who specialize in treating and researching pediatric anterior cruciate ligament (ACL) injuries. The purpose of this meeting was to provide a comprehensive, evidence-informed summary to support the clinician and help children with ACL injury and their parents/guardians make the best possible decisions. Representatives from the following societies attended: American Orthopaedic Society for Sports Medicine; European Paediatric Orthopaedic Society; European Society for Sports Traumatology, Knee Surgery, and Arthroscopy; International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine; Pediatric Orthopaedic Society of North America; and Sociedad Latinoamericana de Artroscopia, Rodilla, y Deporte. Physical therapists and orthopaedic surgeons with clinical and research experience in the field and an ethics expert with substantial experience in the area of sports injuries also participated. This consensus statement addresses 6 fundamental clinical questions regarding the prevention, diagnosis, and management of pediatric ACL injuries. Injury management is challenging in the current landscape of clinical uncertainty and limited scientific knowledge. Injury management decisions also occur against the backdrop of the complexity of shared decision making with children and the potential long-term ramifications of the injury.

Rehabilitation: Common Problems and Solutions

There are numerous complications that can occur following a musculoskeletal injury or surgery in the sporting population. Prevention of the most frequent complications is the key in any successful rehabilitation program, but occasionally problems do occur. A thorough well-designed postoperative or postinjury rehabilitation program may prevent these problems. However, if complications do arise, a team approach among the parties involved in the process to develop an evidenced-based treatment program designed for the underlying complication can successfully treat these issues. The authors discuss the complications seen in sports injuries to the knee, shoulder, elbow, and foot/ankle joints of the body.

Anterior Cruciate Ligament Injury: Return to Play, Function and Long-Term Considerations

Anterior cruciate ligament tears are common and affect young individuals who participate in jumping and pivoting sports. After injury many individuals undergo ligament reconstruction (ACLR) but do not return to play, suffer recurrent injury and osteoarthritis. Outcome studies show that after ACLR, 81% of individuals return to sports, 65% return to their preinjury level and 55% return to competitive sports. Systematic reviews place the risk of ipsilateral retears at 5.8% and contralateral injuries at 11.8%, with recent reports of over 20% failure rate. Approximately 20% to 50% of patients will have evidence of OA within 10 to 20 yr. Factors important in reducing complications include timing of surgery, individualized return to play protocols, and prevention programs for injury. Further understanding of the factors that increase return to play percentages, reduce the risk of recurrent injury and improve long-term outcomes after ACL injury is needed to reduce the burden of these injuries on society.

2018 International Olympic Committee consensus statement on prevention, diagnosis and management of paediatric anterior cruciate ligament (ACL) injuries

In October 2017, the International Olympic Committee hosted an international expert group of physiotherapists and orthopaedic surgeons who specialise in treating and researching paediatric ACL injuries. Representatives from the American Orthopaedic Society for Sports Medicine, European Paediatric Orthopaedic Society, European Society for Sports Traumatology, Knee Surgery & Arthroscopy, International Society of Arthroscopy Knee Surgery and Orthopaedic Sports Medicine, Pediatric Orthopaedic Society of North America and Sociedad Latinoamericana de Artroscopia, Rodilla y Deporte attended. Physiotherapists and orthopaedic surgeons with clinical and research experience in the field, and an ethics expert with substantial experience in the area of sports injuries also participated. Injury management is challenging in the current landscape of clinical uncertainty and limited scientific knowledge. Injury management decisions also occur against the backdrop of the complexity of shared decision-making with children and the potential long-term ramifications of the injury. This consensus statement addresses six fundamental clinical questions regarding the prevention, diagnosis and management of paediatric ACL injuries. The aim of this consensus statement is to provide a comprehensive, evidence-informed summary to support the clinician, and help children with ACL injury and their parents/guardians make the best possible decisions.

Poor knee function after ACL reconstruction is associated with attenuated landing force and knee flexion moment during running

PURPOSE

Poor knee function after anterior cruciate ligament reconstruction (ACLR) may increase the risk of future knee symptoms and knee osteoarthritis via abnormal knee joint loading patterns, particularly during high-impact activity. This study aimed to assess the relationship between poor self-reported or clinically measured knee function and knee moments/vertical ground reaction force (vGRF) in individuals following ACLR.

METHODS

61 participants (mean 16.5 ± 3 months following ACLR, 23 women) completed a patient-reported knee function questionnaire and three hop tests (% of uninvolved limb). Participants were divided into satisfactory and poor knee function groups (poor < 85% patient-reported knee function and/or < 85% hop test symmetry). The knee biomechanics of both groups were assessed with three-dimensional motion analysis during the stance phase of overland running at self-selected speeds, and the association between knee function and knee moments was assessed using analysis of covariance with running speed as a covariate.

RESULTS

Participants with poor knee function (n = 30) ran with significantly smaller peak knee flexion moments (moderate effect size 0.7, p = 0.03) and significantly smaller peak vGRFs (large effect size 1.0, p = 0.002) compared to those with satisfactory knee function (n = 31). No significant differences were observed for knee adduction and knee external rotation moments or knee kinematics.

CONCLUSION

Individuals following ACLR with poor self-reported knee function and/or hop test performance demonstrate knee moments during running that may be associated with lower knee joint contact forces. These findings provide greater understanding of the relationship between knee biomechanics during running and clinical assessments of knee function.

LEVEL OF EVIDENCE

III. Cross-sectional study.

Young athletes return too early to knee-strenuous sport, without acceptable knee function after anterior cruciate ligament reconstruction

PURPOSE

The purpose of this study was to evaluate the return to knee-strenuous sport rate, muscle function and subjective knee function among adolescent patients (15-20 years of age) and adult patients (21-30 years of age) 8 and 12 months, respectively, after anterior cruciate ligament (ACL) reconstruction. It was hypothesised that no differences in outcome would be found between age groups at 8 or 12 months after ACL reconstruction.

METHODS

Cross-sectional data from five tests of muscle function, from the Knee injury and Osteoarthritis Outcome Score (KOOS) and the Tegner Activity Scale (Tegner), performed at 8 and 12 months after a primary ACL reconstruction, were extracted from a rehabilitation outcome register. A total of 270 (51% women) athletes, aged 15-30 years, who were all involved in knee-strenuous sport prior the injury, were included at 8 months after ACL reconstruction. At 12 months 203 (51% women) were included. The return to knee-strenuous-sport rates and the rate of achieving a limb symmetry index of ≥ 90% in all five tests of muscle function, defined as recovery of muscle function, and subjective knee function scores, as measured with the KOOS, were compared between age groups.

RESULTS

The adolescent patients had a higher (50%) return to knee-strenuous sport rate compared with the adult patients (38%) 8 months after ACL reconstruction (p = 0.04). At the 12-month follow-up, no difference was found between the age groups; 74 and 63%, respectively. At the 8-month follow-up, 29% of the patients, in both age groups, who had returned to sport had recovered their muscle function in all five tests of muscle function. At the 12-month follow-up, the corresponding results were 20% for the adolescents and 28% for the adult patients. No difference in mean KOOS scores was found between the age groups at 8 or at 12 months after ACL reconstruction.

CONCLUSION

The majority of young athletes make an early return to knee-strenuous sport after a primary ACL reconstruction, without recovering their muscle function. To set realistic expectations, clinicians are recommended to ensure that young athletes receive information about not to return before muscle function is recovered and that this may take longer time than 12 months.

LEVEL OF EVIDENCE

II.

"I never made it to the pros…" Return to sport and becoming an elite athlete after pediatric and adolescent anterior cruciate ligament injury-Current evidence and future directions

The management of anterior cruciate ligament (ACL) injuries in the skeletally immature and adolescent patient remains an area of controversy in sports medicine. This study, therefore, summarizes and discusses the current evidence related to treating pediatric and adolescent patients who sustain an ACL injury. The current literature identifies a trend towards ACL reconstruction as the preferred treatment option for ACL injuries in the young, largely justified by the risk of further structural damage to the knee joint. Worryingly, a second ACL injury is all too common in the younger population, where almost one in every three to four young patients who sustain an ACL injury and return to high-risk pivoting sport will go on to sustain another ACL injury. The clinical experience of these patients emphasizes the rarity of an athlete who makes it to elite level after a pediatric or adolescent ACL injury, with or without reconstruction. If these patients are unable to make it to an elite level of sport, treatment should possibly be modified to take account of the risks associated with returning to pivoting and strenuous sport. The surveillance of young athletes may be beneficial when it comes to reducing injuries. Further research is crucial to better understand specific risk factors in the young and to establish independent structures to allow for unbiased decision-making for a safe return to sport after ACL injury. Level of evidence V.

Low rates of patients meeting return to sport criteria 9 months after anterior cruciate ligament reconstruction: a prospective longitudinal study

PURPOSE

The purpose of the current prospective study was to assess the changes over time in patients tested at 6 months and 9 months after anterior cruciate ligament reconstruction (ACLR) with a return to sport (RTS) test battery. It was hypothesized that more patients passed RTS criteria at 9 months compared to 6 months.

METHODS

Sixty-two ACLR patients performed a test battery at an average of 6.5 ± 0.7 and 9.5 ± 0.9 months after ACLR. All patients underwent a standardized rehabilitation protocol. The test battery consisted of the following tests: a jump-landing task assessed with the Landing Error Scoring System (LESS), three single-leg hop tasks (single-leg hop test, triple-leg hop test, side hop test), isokinetic quadriceps and hamstring strength at 60, 180 and 300°/s and two questionnaires (IKDC and ACL-RSI). Cut off criteria were set as Limb Symmetry Index (LSI) > 90% (for isokinetic strength and for single-leg hop tasks), LESS < 5, IKDC score within 15th percentage of healthy subjects and ACL-RSI > 56 respectively.

RESULTS

At 6 months, two patients (3.2%) passed all criteria. At 9 months, seven patients (11.3%) passed all criteria. Patients improved in all RTS criteria over time except for the IKDC score. Twenty-nine patients (46.8%) did not pass the strength criterion at 60°/s at 9 months after ACLR.

CONCLUSIONS

The percentages of patients passing all RTS criteria were low at both 6 and 9 months after ACLR. Quadriceps strength revealed persistent deficits and the lack of improvement in the IKDC score questionnaires shows insufficient self-reported knee function for RTS.

LEVEL OF EVIDENCE

III.

Increased odds of patient-reported success at 2 years after anterior cruciate ligament reconstruction in patients without cartilage lesions: a cohort study from the Swedish National Knee Ligament Register

PURPOSE

To investigate whether the surgical technique of single-bundle anterior cruciate ligament (ACL) reconstruction, the visualization of anatomic surgical factors and the presence or absence of concomitant injuries at primary ACL reconstruction are able to predict patient-reported success and failure. The hypothesis of this study was that anatomic single-bundle surgical procedures would be predictive of patient-reported success.

METHODS

This cohort study was based on data from the Swedish National Knee Ligament Register during the period of 1 January 2005 through 31 December 2014. Patients who underwent primary single-bundle ACL reconstruction with hamstring tendons were included. Details on surgical technique were collected using an online questionnaire comprising essential anatomic anterior cruciate ligament reconstruction scoring checklist items, defined as the utilization of accessory medial portal drilling, anatomic tunnel placement, the visualization of insertion sites and pertinent landmarks. A univariate logistic regression model adjusted for age and gender was used to determine predictors of patient-reported success and failure, i.e. 20th and 80th percentile, respectively, in the Knee injury and Osteoarthritis Outcome Score (KOOS), 2 years after ACL reconstruction.

RESULTS

In the 6889 included patients, the surgical technique used for single-bundle ACL reconstruction did not predict the predefined patient-reported success or patient-reported failure in the KOOS₄. Patient-reported success was predicted by the absence of concomitant injury to the meniscus (OR = 0.81 [95% CI, 0.72-0.92], p = 0.001) and articular cartilage (OR = 0.70 [95% CI, 0.61-0.81], p < 0.001). Patient-reported failure was predicted by the presence of a concomitant injury to the articular cartilage (OR = 1.27 [95% CI, 1.11-1.44], p < 0.001).

CONCLUSION

Surgical techniques used in primary single-bundle ACL reconstruction did not predict the KOOS 2 years after the reconstruction. However, the absence of concomitant injuries at index surgery predicted patient-reported success in the KOOS. The results provide further evidence that concomitant injuries at ACL reconstruction affect subjective knee function and a detailed knowledge of the treatment of these concomitant injuries is needed.

LEVEL OF EVIDENCE

Retrospective cohort study, Level III.

2018 International Olympic Committee consensus statement on prevention, diagnosis and management of paediatric anterior cruciate ligament (ACL) injuries

In October 2017, the International Olympic Committee hosted an international expert group of physiotherapists and orthopaedic surgeons who specialise in treating and researching paediatric anterior cruciate ligament (ACL) injuries. Representatives from the American Orthopaedic Society for Sports Medicine, European Paediatric Orthopaedic Society, European Society for Sports Traumatology, Knee Surgery and Arthroscopy, International Society of Arthroscopy Knee Surgery and Orthopaedic Sports Medicine, Pediatric Orthopaedic Society of North America, and Sociedad Latinoamericana de Artroscopia, Rodilla y Deporte attended. Physiotherapists and orthopaedic surgeons with clinical and research experience in the field, and an ethics expert with substantial experience in the area of sports injuries also participated. Injury management is challenging in the current landscape of clinical uncertainty and limited scientific knowledge. Injury management decisions also occur against the backdrop of the complexity of shared decision-making with children and the potential long-term ramifications of the injury. This consensus statement addresses six fundamental clinical questions regarding the prevention, diagnosis, and management of paediatric ACL injuries. The aim of this consensus statement is to provide a comprehensive, evidence-informed summary to support the clinician, and help children with ACL injury and their parents/guardians make the best possible decisions.

Concomitant injuries may not reduce the likelihood of achieving symmetrical muscle function one year after anterior cruciate ligament reconstruction: a prospective observational study based on 263 patients

PURPOSE

A better understanding of patient characteristics and the way common concomitant injuries affect the recovery of muscle function after surgery should help providers to treat patients with anterior cruciate ligament (ACL) injuries. The aim of this study was to determine whether patient characteristics, concomitant injuries and graft choice at ACL reconstruction were associated with symmetrical knee muscle function at one year. The hypothesis was that the presence of concomitant injuries would negatively influence the opportunity to achieve symmetrical knee function at the one-year follow-up.

METHODS

Data was extracted from the Swedish National Knee Ligament Register and a rehabilitation outcome register between August 2012 and December 2016. The patients had been evaluated with a battery of tests comprising knee extension and flexion strength, vertical jump, hop for distance and the side-hop test one year after ACL reconstruction. Univariable and multivariable logistic regression analyses were performed with achieving a limb symmetry index (LSI) of ≥ 90% in all tests of muscle function as primary outcome.

RESULTS

A total of 263 patients with a mean age of 26.7 ± 10.3 years were included in the study (47% females). No patient demographic or intra-operative predictors were found to be significant when attempting to predict the achievement of a symmetrical muscle function. Lateral meniscus injury and a patellar tendon autograft reduced the odds of achieving an LSI of ≥ 90% in knee extension strength, OR = 0.49 [(95% CI 0.25-0.97), p = 0.039] and OR = 0.30 [(95% CI 0.14-0.67), p = 0.0033] respectively. In addition, reduced odds of recovering knee extension strength were found in older patients, OR = 0.76 [(95% CI 0.60-0.98), p = 0.034]. A higher pre-injury level of physical activity increased the odds of recovering knee flexion strength, OR = 1.14 [(95% CI 1.01-1.29), p = 0.037].

CONCLUSION

Intra-operatively identified concomitant injuries or graft choice did not affect the likelihood of recovering symmetrical performance in five different tests of muscle function one year after ACL reconstruction. However, fewer than one in four patients achieved an LSI of ≥ 90% in all tests.

LEVEL OF EVIDENCE

Prospective observational study: Level 2.

Self-Reported Fear Predicts Functional Performance and Second ACL Injury After ACL Reconstruction and Return to Sport: A Pilot Study

Background:

Outcomes after anterior cruciate ligament reconstruction (ACLR) are highly variable. Previous studies have failed to report the relationship between fear, objective measures of function, and reinjury rates. The purpose of this study was to determine whether fear was related to functional performance measures and risk of second ACL injury after ACLR and return to sport (RTS).

Hypothesis:

Fear will be associated with performance on functional testing and second ACL injury rate.

Study Design:

Prospective cohort study.

Level of Evidence:

Level 2.

Methods:

A total of 40 patients cleared to RTS after ACLR completed the Tampa Scale of Kinesiophobia (TSK-11), hop testing, and quadriceps strength testing, bilaterally. Patients were tracked for 12 months after RTS to identify the incidence of second ACL injury. Chi-square analyses determined whether patients with high fear (TSK-11, ≥17) were more likely to have lower levels of activity, greater asymmetry on functional testing, and higher reinjury rates.

Results:

Patients with greater fear on the TSK-11 (≥17) at RTS were 4 times (odds ratio [OR], 3.73; 95% CI, 0.98-14.23) more likely to report lower levels of activity, 7 times (OR, 7.1; 95% CI, 1.5-33.0) more likely to have a hop limb symmetry lower than 95%, and 6 times (OR, 6.0; 95% CI, 1.3-27.8) more likely to have quadriceps strength symmetry lower than 90%. Patients who went on to suffer an ipsilateral second ACL injury had a greater TSK-11 score at the time of RTS (mean, 19.8 ± 4.0) than those who did not suffer a second ACL injury (mean, 16.4 ± 3.6) (P = 0.03). Patients with a TSK-11 score of 19 or greater at the time of RTS were 13 times (relative risk, 13.0; 95% CI, 2.1-81.0) more likely to suffer a second ACL tear within 24 months after RTS.

Conclusion:

Patients with greater self-reported fear were less active, presented with lower single-leg hop performance and isometric quadriceps strength, and had an increased risk of suffering a second ACL injury in the 24 months after RTS.

Clinical Relevance:

Self-reported fear of movement/reinjury after ACLR at the time of RTS may be an important measure to incorporate into discharge criteria prior to release to return to pivoting and cutting sports after ACLR.

Clinical Factors That Predict a Second ACL Injury After ACL Reconstruction and Return to Sport: Preliminary Development of a Clinical Decision Algorithm

Background

Biomechanical predictors of a second anterior cruciate ligament (ACL) injury after ACL reconstruction (ACLR) and return to sport (RTS) have been identified; however, these measures may not be feasible in a standard clinical environment.

Purpose/Hypothesis

The purpose of this study was to evaluate whether standard clinical measures predicted the risk of second ACL injuries. The hypothesis tested was that a combination of strength, function, and patient-reported measures at the time of RTS would predict the risk of second ACL injuries with high sensitivity and specificity.

Study Design

Case-control study; Level of evidence, 3 and Cohort study (prognosis); Level of evidence, 1.

Methods

A total of 163 participants (mean age, 16.7 ± 3.0 years) who underwent primary ACLR and were able to RTS were evaluated. All participants completed an assessment of isokinetic strength, hop testing, balance, and the Knee Injury and Osteoarthritis Outcome Score (KOOS). Participants were tracked for a minimum of 24 months to identify occurrences of a second ACL injury. The initial 120 participants enrolled were used to develop a clinical prediction model that utilized classification and regression tree (CART) analysis, and the remaining 43 participants enrolled were used as a validation dataset. Additional analyses were performed in all 163 participants using Kaplan-Meier analysis and Cox proportional hazards modeling.

Results

Approximately 20% (23/114) of the initial subset of the cohort suffered a second ACL injury. CART analysis identified age, sex, knee-related confidence, and performance on the triple hop for distance at the time of RTS as the primary predictors of a second ACL injury. Using these variables, a model was generated from which high-risk (n = 53) and low-risk groups (n = 61) were identified. A total of 22 participants in the high-risk group and 1 participant in the low-risk group suffered a second ACL injury. High-risk participants fit 1 of 2 profiles: (1) age <19 years, triple hop for distance between 1.34 and 1.90 times body height, and triple hop for distance limb symmetry index (LSI) <98.5% (n = 43) or (2) age <19 years, triple hop for distance >1.34 times body height, triple hop for distance LSI >98.5%, female sex, and high knee-related confidence (n = 10). The validation step identified the high-risk group as being 5 times (odds ratio, 5.14 [95% CI, 1.00-26.46]) more likely to suffer a second ACL injury, with a sensitivity of 66.7% and specificity of 72.0%.

Conclusion

These findings recognize measures that accurately identify young patients at high risk of sustaining a second ACL injury within 24 months after RTS. The development of a clinical decision algorithm to identify high-risk patients, inclusive of clinically feasible variables such as age, sex, confidence, and performance on the triple hop for distance, can serve as a foundation to re-evaluate appropriate discharge criteria for RTS.

The Utility of Objective Strength and Functional Performance to Predict Subjective Outcomes After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Many clinicians release patients to return to activity after anterior cruciate ligament reconstruction (ACLR) based on time from surgery despite deficits in muscle strength and function. It is unclear whether symmetry or unilateral performance is the best predictor of subjective outcomes after ACLR.

PURPOSE

To determine physical performance predictors of patient-reported outcomes after reconstruction.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 88 participants (49 males, 39 females; mean ± SD height, 174.0 ± 9.6 cm; weight, 76.1 ± 18.5 kg; age, 19.4 ± 3.7 years) who underwent primary, unilateral ACLR volunteered for this study. Participants had undergone reconstruction a mean of 6.9 ± 1.8 months (range, 5.0-14.1 months) before the study. All participants underwent strength testing as well as hop testing and then completed the International Knee Documentation Committee (IKDC) and Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaires. Stepwise linear regression models were used for symmetry and unilateral performance to identify the proportion of variance explained in the IKDC score, KOOS total score, KOOS-sport subscale, and time from surgery, as well as receiver operating characteristic (ROC) curve analyses on those variables that explained the most variance in patient-reported outcomes to determine cutoff thresholds.

RESULTS

No significant correlations were found between time from surgery and objective performance. The only significant predictors of IKDC score were single-hop limb symmetry index (LSI) and age (R2 = 0.177) and unilateral triple-hop performance and age (R2 = 0.228). The cutoff for single-hop symmetry was 0.92 (area under the curve [AUC], 0.703; P = .012), and the cutoff for normalized triple-hop distance was 3.93 (AUC, 0.726; P = .005). When stratified by age, the cutoff for single-hop symmetry was 0.81 (AUC, 0.721; P = .051) for younger patients (age <19.1 years) and was not significant for older patients (age ≥19.1 years). The cutoff for normalized triple-hop distance was 3.85 (AUC, 0.832; P = .005) in older patients and was not significant for younger patients. The only significant predictors of KOOS-sport subscale were single-hop LSI (R2 = 0.140) and normalized knee extensor power at 180 deg/s (R2 = 0.096). When subjective outcomes were predicted based on KOOS-sport subscale, the cutoff for single-hop symmetry was 0.85 (AUC, 0.692; P = .018).

CONCLUSION

Hopping performance is the most predictive functional variable of subjective outcomes after reconstruction. Single-hop symmetry was most important for younger patients and unilateral triple-hop distance was most important for older patients. Clinicians should consider hopping performance when making return-to-activity decisions after ACLR.

Reference values for fatigued versus non-fatigued limb symmetry index measured by a newly designed single-leg hop test battery in healthy subjects: a pilot study

Purpose

There is sparse evidence for return to sport criteria after knee injury. Functional performance deficits, particularly in fatigued muscular condition, should be verified prior to the attempt to return to high-risk pivoting sports. The purpose of this study was to generate reference values for the limb symmetry index (LSI) of healthy subjects in fatigued and non-fatigued muscular condition in a newly designed test battery.

Methods

Forty-two healthy subjects [22 females, 20 males; mean (SD) age 30.4 (6.6) years] were evaluated using a test battery consisting of an isometric strength test, a series of five single-leg hop tests and an integrated fatigue protocol. Subjective physical activity was assessed with the Tegner Activity Scale (TAS). The cut-off values for healthy subjects were calculated considering the fifth percentile as the minimum reference value for the LSI and single-leg hop distance.

Results

The mean (SD) overall LSI was 98.8% (4.6). No significant gender or age specific differences in limb symmetry were observed. The comparison of the non-fatigued LSI with the overall LSI revealed no clinically relevant change due to muscular fatigue. Repeated measures ANOVA revealed a significant within effect on fatigue/non-fatigue condition (F_(1,38) = 18.000; p < 0.001, η² = 0.321) on absolute single-leg hop distance. Moreover, a significant between effect on the TAS-parameter (F_(1,38) = 5.928; p = 0.020, η² = 0.135 between: TAS ≤ 5/TAS > 5) and on gender (F_(1,38) = 23.956; p < 0.001, η² = 0.387) could be detected.

Conclusions

The absolute jumping distance in the single-leg hop for distance was significantly reduced due to fatigue. No clinically relevant effect of muscular fatigue was observed on limb symmetry in our study sample. Gender and physical activity are important factors to be considered when interpreting reference values.

Electronic supplementary material

The online version of this article (10.1007/s11332-017-0410-5) contains supplementary material, which is available to authorized users.

Isokinetic Extension Strength Is Associated With Single-Leg Vertical Jump Height

Background

Isokinetic strength testing is an important tool in the evaluation of the physical capacities of athletes as well as for decision making regarding return to sports after anterior cruciate ligament (ACL) reconstruction in both athletes and the lay population. However, isokinetic testing is time consuming and requires special testing equipment.

Hypothesis

A single-jump test, regardless of leg dominance, may provide information regarding knee extension strength through the use of correlation analysis of jump height and peak torque of isokinetic muscle strength.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

A total of 169 patients who underwent ACL reconstruction were included in this study. Isokinetic testing was performed on the injured and noninjured legs. Additionally, a single-leg countermovement jump was performed to assess jump height using a jump accelerometer sensor. Extension strength values were used to assess the association between isokinetic muscle strength and jump height.

Results

The sample consisted of 60 female (mean age, 20.8 ± 8.3 years; mean weight, 61.7 ± 6.5 kg; mean height, 167.7 ± 5.3 cm) and 109 male (mean age, 23.2 ± 7.7 years; mean weight, 74.6 ± 10.2 kg; mean height, 179.9 ± 6.9 cm) patients. Bivariate correlation analysis showed an association (r = 0.56, P < .001) between jump height and isokinetic extension strength on the noninvolved side as well as an association (r = 0.52, P < .001) for the involved side. Regression analysis showed that in addition to jump height (beta = 0.49, P < .001), sex (beta = -0.17, P = .008) and body mass index (beta = 0.37, P < .001) affected isokinetic strength. The final model explained 51.1% of the variance in isokinetic muscle strength, with jump height having the strongest impact (beta = 0.49, P < .001) and explaining 31.5% of the variance.

Conclusion

Initial analysis showed a strong association between isokinetic strength and jump height. The study population encompassed various backgrounds, skill levels, and activity profiles, which might have affected the outcome. Even after controlling for age and sex, isokinetic strength was still moderately associated with jump height. Therefore, the jump technique and type of sport should be considered in future research.

THE RELATIONSHIP BETWEEN PRE-OPERATIVE AND TWELVE-WEEK POST-OPERATIVE Y-BALANCE AND QUADRICEPS STRENGTH IN ATHLETES WITH AN ANTERIOR CRUCIATE LIGAMENT TEAR

BACKGROUND

Pre-operative quadriceps strength may have a positive influence on post-operative function and outcomes at time of return to sport. Little consideration has been given to quadriceps strength during the early post-operative timeframes. Twelve-week post-operative anterior cruciate ligament reconstruction (ACL-R) is considered a critical time point for progression in the rehabilitation process. There is currently limited research looking at the relationship between clinical measurements pre-operatively and at 12-weeks following ACL-R.

PURPOSE/HYPOTHESIS

The primary purpose of this study was to examine the differences between Y-Balance Test Lower Quarter (YBT-LQ) and isokinetic quadriceps strength tested pre-operatively and post-operatively following ACL-R (12-weeks).

STUDY DESIGN

Within subject, repeated measures.

METHODS

Thirty-nine participants (15.6 ± 1.5 y/o) were diagnosed with an ACL tear and were undergoing rehabilitation to return to a sport requiring cutting and pivoting were included. YBT-LQ and isokinetic quadriceps strength were assessed pre-operatively and at 12-weeks after ACL-R. YBT-LQ composite scores were calculated bilaterally and isokinetic quadriceps strength was tested using the Biodex Multi-Joint Testing and Rehabilitation System. Paired T-tests were used to determine mean group differences between YBT-LQ and isokinetic quadriceps strength scores pre-operatively and at 12-weeks post-operative. A Pearson Correlation was performed to determine relationships between variables at both time points.

RESULTS

There was a significant improvement in YBT-LQ composite scores from pre-operative to 12-weeks post-operative on both the involved (Pre-operative: 89.0 ± 7.7; 12-weeks: 94.1 ± 7.1, p<0.001) and uninvolved (Pre-operative: 92.6 ± 6.2; 12-weeks: 97.6 ± 6.8, p<0.001) limbs. Quadriceps strength decreased significantly from pre-operative to 12-weeks on the involved limb (Pre-operative: 82.3 ftlbs ± 38.6; 12-weeks: 67.9 ftlbs±27.4, p<0.01), but no differences were found on the uninvolved limb (Pre-operative: 117.3ftlbs ± 42.0; 12-weeks: 121.7ftlbs ± 41.5, p = 0.226).

CONCLUSIONS

Involved limb quadriceps strength decreases from time of pre-operative to 12-weeks following ACL-R.

LEVEL OF EVIDENCE

3.

Clinical course and recommendations for patients after anterior cruciate ligament injury and subsequent reconstruction: A narrative review

Almost all athletes who have suffered an anterior cruciate ligament (ACL) injury expect a full return to sports at the same pre-injury level after ACL reconstruction (ACLR). Detailed patient information on the reasonable outcomes of the surgery may be essential to improve patient satisfaction.

Pre-operative rehabilitation before ACLR should be considered as an addition to the standard of care to maximise functional outcomes after ACLR.

We propose an optimised criterion-based rehabilitation programme within a biopsychosocial framework.

No benchmark exists for evaluating return-to-sport (RTS) readiness after ACLR. Therefore, the authors propose a multi-factorial RTS test battery. A combination of both physical and psychological elements should be included in the RTS test battery.

There is need for shared decision-making regarding RTS.

Cite this article: EFORT Open Rev 2017;2:410-420. DOI: 10.1302/2058-5241.2.170011

Report of the Primary Outcomes for Gait Mechanics in Men of the ACL-SPORTS Trial: Secondary Prevention With and Without Perturbation Training Does Not Restore Gait Symmetry in Men 1 or 2 Years After ACL Reconstruction

BACKGROUND

Movement asymmetries during walking are common after anterior cruciate ligament (ACL) injury and reconstruction and may influence the early development of posttraumatic osteoarthritis. Preoperative neuromuscular training (like perturbation training, which is neuromuscular training requiring selective muscle activation in response to surface perturbations) improves gait asymmetries and functional outcomes among people who are ACL-deficient, but the effect of postoperative perturbation training on gait mechanics after ACL reconstruction is unknown.

QUESTIONS/PURPOSES

Among men undergoing ACL reconstruction, we sought to compare strength, agility, and secondary prevention (SAP) treatment with SAP plus perturbation training (SAP+PERT) with respect to (1) gait mechanics; and (2) elimination of gait asymmetries 1 and 2 years after ACL reconstruction.

METHODS

Forty men were randomized into a SAP group or a SAP+PERT group after ACL reconstruction and before returning to preinjury activities. Participants were required to achieve ≥ 80% quadriceps muscle strength symmetry, minimal knee effusion, full ROM, no reports of pain, and completion of a running progression (all between 3 and 9 months postoperatively) before enrollment. Of 94 potentially eligible athletic male patients evaluated < 9 months after ACL reconstruction, 54 were excluded for prespecified reasons. Participants underwent motion analysis during overground walking at 1 and 2 years postoperatively. Variables of interest included (1) sagittal and frontal plane hip and knee angles and moments at peak knee flexion angle; (2) sagittal plane hip and knee angles and moments at peak knee extension angle; (3) sagittal plane hip and knee excursion during weight acceptance; and (4) sagittal plane hip and knee excursion during midstance. We also calculated the proportion of athletes in each group who walked with clinically meaningful interlimb asymmetry in sagittal plane hip and knee variables and compared these proportions using odds ratios. There was no differential loss to followup between groups.

RESULTS

There were no differences between the SAP or SAP+PERT groups for the biomechanical gait variables. The involved limb's knee excursion during midstance for the SAP (mean ± SD: 1 year: 15° ± 5°; 2 years: 16° ± 5°) and SAP+PERT (1 year: 16° ± 5°; 2 years: 15° ± 4°) athletes was not different between groups at 1 year (mean difference: -1°; 95% confidence interval [CI], -5° to 2°; p = 0.49) or 2 years (mean difference: 1°; 95% CI, -2° to 4°; p = 0.54). There were no differences between SAP and SAP+PERT athletes regarding the elimination of gait asymmetries, and gait asymmetries persisted to a large degree in both groups 1 and 2 years postoperatively. At 1 year, 11 of 18 SAP and 11 of 20 SAP+PERT athletes walked with truncated knee excursions during weight acceptance (odds ratio: 0.8, p = 0.70) and midstance (SAP 12 of 18, SAP+PERT 12 of 20; odds ratio: 0.8, p = 0.67), whereas at 2 years postoperatively, truncated knee excursions during weight acceptance (SAP seven of 17, SAP+PERT eight of 19; odds ratio: 1.0, p = 0.96) and midstance (SAP five of 17, SAP+PERT 11 of 19; odds ratio: 3.3, p = 0.09) remained prevalent.

CONCLUSIONS

We found that a comprehensive, progressive return-to-sport training program with or without perturbation was not effective at restoring interlimb symmetry among men 1 or 2 years after ACL reconstruction. Although gait asymmetries improved from 1 to 2 years postoperatively, meaningful asymmetries persisted in both groups. To restore gait symmetry after ACL reconstruction, additional interventions likely are necessary.

LEVEL OF EVIDENCE

Level II, therapeutic study.

Report of the Clinical and Functional Primary Outcomes in Men of the ACL-SPORTS Trial: Similar Outcomes in Men Receiving Secondary Prevention With and Without Perturbation Training 1 and 2 Years After ACL Reconstruction

BACKGROUND

Athletes often are cleared to return to activities 6 months after anterior cruciate ligament (ACL) reconstruction; however, knee function measures continue to improve up to 2 years after surgery. Interventions beyond standard care may facilitate successful return to preinjury activities and improve functional outcomes. Perturbation training has been used in nonoperative ACL injury and preoperative ACL reconstruction rehabilitation, but has not been examined in postoperative ACL reconstruction rehabilitation, specifically return to sport rehabilitation.

QUESTIONS/PURPOSES

The purpose of this study was to determine whether there were differences at 1 and 2 years after ACL reconstruction between the male SAP (strengthening, agility, and secondary prevention) and SAP+PERT (SAP protocol with the addition of perturbation training) groups with respect to (1) quadriceps strength and single-legged hop limb symmetry; (2) patient-reported knee outcome scores; (3) the proportion who achieve self-reported normal knee function; and (4) the time from surgery to passing return to sport criteria.

METHODS

Forty men who had completed ACL reconstruction rehabilitation and met enrollment criteria (3-9 months after ACL reconstruction, > 80% quadriceps strength limb symmetry, no pain, full ROM, minimal effusion) were randomized into the SAP or SAP+PERT groups of the Anterior Cruciate Ligament-Specialised Post-Operative Return to Sports trial (ACL-SPORTS), a single-blind randomized clinical study of secondary prevention and return to sport. Quadriceps strength, single-legged hopping, the International Knee Documentation Committee (IKDC) 2000 subjective knee form, Knee Injury and Osteoarthritis Outcome Score (KOOS)-sports and recreation, and KOOS-quality-of-life subscales were collected 1 and 2 years after surgery by investigators blind to group. Athletes were categorized as having normal or abnormal knee function at each time point based on IKDC score, and the time until athletes passed strict return-to-sport criteria was also recorded. T-tests, chi square tests, and analyses of variance were used to identify differences between the treatment groups over time.

RESULTS

There were no differences between groups for quadriceps symmetry (1 year: SAP = 101% ± 14%, SAP+PERT = 101% ± 14%; 2 years: SAP = 103% ± 11%, SAP+PERT = 98% ± 14%; mean differences between groups at 1 year: 0.4 [-9.0 to 9.8], 2 years = 4.5 [-4.3 to 13.1]; mean difference between 1 and 2 years: SAP = -1.0 [-8.6 to 6.6], SAP+PERT = 3.0 [-4.3 to 10.3], p = 0.45) or single-legged hop test limb symmetry. There were no clinically meaningful differences for any patient-reported outcome measures. There was no difference in the proportion of athletes in each group who achieved normal knee function at 1 year (SAP 14 of 19, SAP+PERT 18 of 20, odds ratio 0.31 [0.5-19.0]; p = 0.18); however, the SAP+PERT group had fewer athletes with normal knee function at 2 years (SAP 17 of 17, SAP+PERT 14 of 19, p = 0.03). There were no differences between groups in the time to pass return to sport criteria (SAP = 325 ± 199 days, SAP+PERT = 233 ± 77 days; mean difference 92 [-9 to 192], p = 0.09).

CONCLUSIONS

This randomized trial found few differences between an ACL rehabilitation program consisting of strengthening, agility, and secondary prevention and one consisting of those elements as well as perturbation training. In the absence of clinically meaningful differences between groups in knee function and self-reported outcomes measures, the results indicate that perturbation training may not contribute additional benefit to the strengthening, agility, and secondary prevention base of the ACL-SPORTS training program.

LEVEL OF EVIDENCE

Level II, therapeutic study.

Younger Patients and Men Achieve Higher Outcome Scores Than Older Patients and Women After Anterior Cruciate Ligament Reconstruction

BACKGROUND

There is some evidence that functional performance and validated outcome scores differ according to the gender, age, and sport participation status of a patient after anterior cruciate ligament (ACL) reconstruction. However, the impact of these three factors, and interaction among them, has not been studied across a large relatively homogeneous group of patients to better elucidate their impact.

QUESTIONS/PURPOSES

We reviewed a large cohort of patients who had undergone ACL reconstruction to determine if ROM, knee laxity, objective performance measures, and validated outcome scores differed according to (1) gender; (2) age; and (3) sport participation status.

METHODS

This was a retrospective analysis of prospectively collected data. Between 2007 and 2016, we performed 3452 single-bundle ACL reconstructions in patients who participated in sport before ACL injury. Of those, complete followup (including preoperative scores and scores at 1 year after surgery; mean, 14 months; range, 12-20 months) was available on 2672 (77%) of patients. Those lost to followup and those accounted for were not different in terms of age, gender, and sports participation at baseline. The study group consisted of 1726 (65%) men and 946 (35%) women with a mean ± SD age of 28 ± 10 years. For these patients, the following measures were obtained: knee ROM (flexion and extension deficit), instrumented knee laxity, single and triple hop for distance limb symmetry index (LSI), International Knee Documentation Committee (IKDC) subjective evaluation, and Single Assessment Numeric Evaluation score. Mean scores and measures of variability were calculated for each outcome measure. Comparisons were made among gender, age, and sport status.

RESULTS

Men had less knee laxity after reconstruction (men 1.1 ± 2.2 mm, women 1.3 ± 2.4 mm; mean difference 0.2 mm [0.1-0.4], p < 0.001), greater limb symmetry (single limb hop men: 94% ± 12%, women 91% ± 13%, mean difference 3% [2%-4%], p < 0.001), and higher IKDC scores than did women (men 84 ± 12, women 82 ± 12, mean difference 2 [1-3], p < 0.001). With the exception of instrumented laxity, all outcome measures showed reduced deficits and higher scores in younger patients. This was most marked for LSI scores between the youngest and oldest aged patient groups (crossover hop: < 16 years 99% ± 10%, > 45 years 90% ± 16%, mean difference: 9 [5-11], p < 0.001). Patients who had returned to their preinjury sport also scored higher and had smaller deficits for all outcomes except ROM compared with patients who had not returned to sport at the time of followup (IKDC subjective: returned 90 ± 9, no sport 79 ± 12, mean difference 11 points [9-12], p < 0.001; single limb hop: returned 97 ± 10, no sport 91 ± 14, mean difference 6% [5%-7%], p < 0.001).

CONCLUSIONS

This study showed that some of the most commonly used functional performance and validated clinical scores for ACL reconstruction are superior for patients who are younger, male, and have returned to preinjury sport. Reference to these data allows clinicians to more effectively evaluate a patient based on their age, gender, and sport status when making return to sport and rehabilitation decisions.

LEVEL OF EVIDENCE

Level III, therapeutic study.

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

BACKGROUND

Assessing athletes' readiness is a key component for successful outcomes after ACL reconstruction (ACLR).

OBJECTIVES

To investigate whether return-to-activity criteria, individually or in combination, at 6 months after ACLR can predict return to participation in the same preinjury activity level at 12 and 24 months after ACLR.

METHODS

Ninety-five level I/II participants completed return-to-activity criteria testing (isometric quadriceps index, single-legged hop tests, Knee Outcome Survey-Activities of Daily Living Scale (KOS-ADLS) and Global Rating Score (GRS)) at 6 months after ACLR. The PASS group was defined as scoring >90% on all criteria and the FAIL group as scoring <90% on any criteria. At 12 and 24 months after ACLR, participants were asked if they had returned to participate in the same preinjury activity level or not. All return-to-activity criteria, except quadriceps index, were entered into the logistic regression model.

RESULTS

81% and 84.4% of the PASS group returned to participation in the same preinjury activity level, while only 44.2% and 46.4% of the FAIL group returned at 12 and 24 months, respectively, after ACLR. The 6-meter timed hop, single hop and triple hop limb symmetry indexes; GRS; and KOS-ADLS individually predicted the outcome of interest at 12 months after ACLR (range: R²: 0.12-0.22, p<0.024). In combination, they explained 27% of the variance (p=0.035). All hop tests, individually, predicted the outcome of interest at 24 months after ACLR (range: R²: 0.26-0.37; p<0.007); in combination they explained 45% of the variance (p<0.001).

CONCLUSION

Return to participation in the same preinjury activity level at 12 and 24 months after ACLR was higher in those who passed the criteria compared with those who failed. Individual and combined return-to-activity criteria predicted the outcomes of interest, with the hop tests as consistent predictors at 12 and 24 months after ACLR.

Accelerated Return to Sport After Anterior Cruciate Ligament Reconstruction and Early Knee Osteoarthritis Features at 1 Year: An Exploratory Study

BACKGROUND

A timely return to competitive sport is a primary goal of anterior cruciate ligament reconstruction (ACLR). It is not known whether an accelerated return to sport increases the risk of early-onset knee osteoarthritis (KOA).

OBJECTIVE

To determine whether an accelerated return to sport post-ACLR (ie, <10 months) is associated with increased odds of early KOA features on magnetic resonance imaging (MRI) 1 year after surgery and to evaluate the relationship between an accelerated return to sport and early KOA features stratified by type of ACL injury (isolated or concurrent chondral/meniscal injury) and lower limb function (good or poor).

DESIGN

Cross-sectional study.

SETTING

Private radiology clinic and university laboratory.

PARTICIPANTS

A total of 111 participants (71 male; mean age 30 ± 8 years) 1-year post-ACLR.

METHODS

Participants completed a self-report questionnaire regarding postoperative return-to-sport data (specific sport, postoperative month first returned), and isotropic 3-T MRI scans were obtained.

OUTCOME MEASURES

Early KOA features (bone marrow, cartilage and meniscal lesions, and osteophytes) assessed with the MRI OA Knee Score. Logistic regression analyses evaluated the odds of early KOA features with an accelerated return to sport (<10 months post-ACLR versus ≥10 months or no return to sport) in the total cohort and stratified by type of ACL injury and lower limb function.

RESULTS

Forty-six (41%) participants returned to competitive sport <10 months post-ACLR. An early return to sport was associated with significantly increased odds of bone marrow lesions (odds ratio [OR] 2.7, 95% confidence interval [CI] 1.3-6.0) but not cartilage (OR 1.2, 95% CI 0.5-2.6) or meniscal lesions (OR 0.8, 95% CI 0.4-1.8) or osteophytes (OR 0.6, 95% CI 0.3-1.4). In those with poor lower limb function, early return to sport exacerbated the odds of bone marrow lesions (OR 4.6, 95% CI 1.6-13.5), whereas stratified analyses for type of ACL injury did not reach statistical significance.

CONCLUSION

An accelerated return to sport, particularly in the presence of poor lower limb function, may be implicated in posttraumatic KOA development.

LEVEL OF EVIDENCE

IV.

Young Athletes After Anterior Cruciate Ligament Reconstruction With Single-Leg Landing Asymmetries at the Time of Return to Sport Demonstrate Decreased Knee Function 2 Years Later

BACKGROUND

Previous work shows that young athletes after anterior cruciate ligament reconstruction (ACLR) demonstrate single-leg (SL) landing movement asymmetries at the time of return to sport (RTS); however, the effect of movement asymmetries on longitudinal knee-related function after ACLR has not been examined. Hypothesis/Purpose: The purpose of this study was to examine the effect of SL drop-landing movement symmetry at the time of RTS on knee-related function 2 years later in young athletes after ACLR. The first hypothesis was that young athletes who demonstrated SL drop-landing asymmetries at RTS would demonstrate decreased knee function 2 years later compared with those who demonstrated symmetric SL drop-landing mechanics. The second hypothesis was that SL drop-landing movement symmetry at RTS would be associated with knee functional recovery 2 years later.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

This study included 48 young athletes who had undergone ACLR and were assessed at the time of RTS (77% female; mean [±SD] age at RTS, 17.6 ± 2.6 years) and followed for 2 years after RTS. Three sagittal-plane landing variables of interest were calculated using 3-dimensional motion analysis during an SL drop-landing task at the time of RTS: knee flexion excursion, peak internal knee extension moment, and peak trunk flexion. The limb symmetry index (LSI) was calculated for each landing variable using the following: LSI = (involved/uninvolved) × 100%. The LSI was used to divide the cohort into symmetric (SYM) and asymmetric (ASYM) groups for each landing variable: knee flexion excursion (SYM: LSI ≥ 90% [n = 23]; ASYM: LSI < 85% [n = 18]), peak internal knee extension moment (SYM: LSI ≥ 90% [n = 19]; ASYM: LSI < 85% [n = 22]), and peak trunk flexion (SYM: LSI ≤ 105% [n = 25]; ASYM: LSI > 115% [n = 19]). At 2 years after RTS, knee-related function was evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC) subjective knee form, and performance on SL hop tests. Functional recovery was defined based on literature cutoffs for knee-related functional measures. Differences in 2-year function were compared between the symmetry groups using Mann-Whitney U tests because of nonnormality. Logistic regression was used to determine if landing symmetry at the time of RTS would be associated with 2-year knee functional recovery after RTS.

RESULTS

The ASYM knee flexion excursion group demonstrated decreased function at 2 years after RTS compared with the SYM group on the KOOS-Pain (ASYM: 93.0 ± 8.2; SYM: 98.4 ± 3.0; P = .008) and the KOOS-Quality of Life (ASYM: 81.6 ± 16.1; SYM: 94.1 ± 9.7; P = .008). Knee flexion excursion was associated with knee functional recovery on the KOOS-Pain and the KOOS-Quality of Life ( P = .033 and P = .012, respectively) at 2 years after RTS, after controlling for the quadriceps strength LSI and graft type.

CONCLUSION

Young athletes after ACLR with asymmetries in knee kinematics at the time of RTS reported decreased self-reported function 2 years later; however, the clinical importance of these differences needs to be further understood.

Gait mechanics and second ACL rupture: Implications for delaying return-to-sport

Second anterior cruciate ligament rupture is a common and devastating injury among young women who return to sport after ACL reconstruction, but it is inadequately understood. The purpose of this study was to compare gait biomechanics and return-to-sport time frames in a matched cohort of young female athletes who, after primary ACLR, returned to sport without re-injury or sustained a second ACL injury. Approximately 6 months after primary reconstruction, 14 young women (age 16 ± 2 years) involved in jumping, cutting, and pivoting sports underwent motion analysis testing after physical therapy and impairment resolution. Following objective return-to-sport clearance, seven athletes sustained a second ACL rupture within 20 months of surgery (13.4 ± 4.9 months). We matched them by age, sex, and sport-level to seven athletes who returned to sports without re-injury. Data were analyzed using a previously validated, EMG-informed, patient-specific musculoskeletal model. Compared to athletes without re-injury, athletes who sustained a second ACL injury received surgery sooner (p = 0.023), had post-operative impairments resolved earlier (p = 0.022), reached criterion-based return-to-sport benchmarks earlier (p = 0.024), had higher body mass index (p = 0.039), and walked with lower peak knee flexor muscle forces bilaterally (p = 0.021). Athletes who sustained a second injury also tended to walk with larger (p = 0.089) and more symmetrical peak knee flexion angles and less co-contraction, all indicative of a more normal gait pattern. Statement of Clinical Significance: Delayed return-to-sport clearance even in the absence of gait or clinical impairments following primary ACL reconstruction may be necessary to mitigate second ACL injury risk in young women. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1894-1901, 2017.

ACL Return to Sport Guidelines and Criteria

PURPOSE OF REVIEW

Because of the epidemiological incidence of anterior cruciate ligament (ACL) injuries, the high reinjury rates that occur when returning back to sports, the actual number of patients that return to the same premorbid level of competition, the high incidence of osteoarthritis at 5-10-year follow-ups, and the effects on the long-term health of the knee and the quality of life for the patient, individualizing the return to sports after ACL reconstruction (ACL-R) is critical. However, one of the challenging but unsolved dilemmas is what criteria and clinical decision making should be used to return an athlete back to sports following an ACL-R. This article describes an example of a functional testing algorithm (FTA) as one method for clinical decision making based on quantitative and qualitative testing and assessment utilized to make informed decisions to return an athlete to their sports safely and without compromised performance. The methods were a review of the best current evidence to support a FTA.

RECENT FINDINGS

In order to evaluate all the complicated domains of the clinical decision making for individualizing the return to sports after ACL-R, numerous assessments need to be performed including the biopsychosocial concepts, impairment testing, strength and power testing, functional testing, and patient-reported outcomes (PROs). The optimum criteria to use for individualizing the return to sports after ACL-R remain elusive. However, since this decision needs to be made on a regular basis with the safety and performance factors of the patient involved, this FTA provides one method of quantitatively and qualitatively making the decisions. Admittedly, there is no predictive validity of this system, but it does provide practical guidelines to facilitate the clinical decision making process for return to sports. The clinical decision to return an athlete back into competition has significant implications ranging from the safety of the athlete, to performance factors and actual litigation issues. By using a multifactorial FTA, such as the one described, provides quantitative and qualitatively criteria to make an informed decision in the best interests of the athlete.

Development of a Clinician-Rated Drop Vertical Jump Scale for Patients Undergoing Rehabilitation After Anterior Cruciate Ligament Reconstruction: A Delphi Approach

Study Design Delphi panel study. Background Biomechanical parameters measured during a drop vertical jump task are risk factors for anterior cruciate ligament (ACL) injury and are targeted during rehabilitation after ACL reconstruction. A clinically feasible tool that quantifies observed performance on the drop vertical jump would help inform treatment efforts. The content and scoring of such a tool should be deliberated on by a group of experts throughout its development. Objectives To establish consensus on the content and scoring of a clinician-rated drop vertical jump scale (DVJS) for use during rehabilitation after ACL reconstruction. Methods Using a modified Delphi process, a panel of experts (researchers and clinicians) on the risk factors, prevention, treatment, and biomechanics of ACL injury anonymously critiqued versions of a DVJS. The DVJS was developed iteratively, based on the feedback from the panel, using Likert scale responses to questions and providing written comments. Three to 5 rounds were planned a priori, with a requirement of 75% agreement on included items after the final round. Results Twenty of the 31 invited experts (65%) participated. Approximately 93% agreement was achieved after the fourth round. Final items on the scale included the rating of knee valgus collapse (no collapse to extreme collapse) and the presence of other undesirable movements, including lateral trunk lean, insufficient knee flexion, and limb-to-limb asymmetry. Conclusion The Delphi process resulted in a beta version of a DVJS. Expert consensus was achieved on its content and scoring to support further clinical testing of the scale. J Orthop Sports Phys Ther 2017;47(8):557-564. Epub 6 Jul 2017. doi:10.2519/jospt.2017.7183.

Relationships of Muscle Function and Subjective Knee Function in Patients After ACL Reconstruction

BACKGROUND

After anterior cruciate ligament reconstruction (ACLR), relationships between objective measures of muscle function and patient-reported outcomes may change over time. Examining these measures at different time frames after surgery may help develop individualized approaches to improve post-ALCR analysis.

PURPOSE

To examine the associations between subjective knee function and lower-extremity muscle function in individual patients at various time points after ACLR.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Fifty-one participants who underwent primary, unilateral ACLR (15 males, 36 females; mean age, 22.9 ± 4.5 years; mean height, 172.4 ± 10.1 cm; mean weight, 68.7 ± 13.1 kg) were separated into 3 groups depending on time since surgery (early, <2 years; middle, 2-5 years; late, >5 years). Subjective knee function was quantified using the International Knee Documentation Committee (IKDC) subjective knee form and the Knee injury and Osteoarthritis Outcome Score (KOOS). Isometric knee extension and flexion strength were collected at 90 deg/s. Single-leg hop performance was measured using the single hop, triple hop, cross-over hop, and 6-m timed hop. Coefficient correlations were calculated between subjective knee function and objective measures of muscle function for each group.

RESULTS

The early group demonstrated moderate correlations between the KOOS and unilateral measures of flexion peak torque (r = 0.514, P = .035) and flexion power (r = 0.54, P = .027). The middle group demonstrated the strongest correlations between the KOOS and symmetry measures of the single hop (r = 0.69, P = .002) and extension work (r = 0.71, P = .002) as well as unilateral measures of the triple hop (r = 0.52, P = .034) and extension work (r = 0.66, P = .004). The late group demonstrated strong correlations between the 6-m timed hop symmetry and the IKDC (r = 0.716, P = .001) and KOOS (r = 0.71, P = .001).

CONCLUSION

Patients with a post-ACLR status of less than 2 years exhibited stronger relationships with unilateral strength measures to subjective function; graft type was found to change these relationships. Patients at 2 to 5 years postsurgery demonstrated relationships with both unilateral and symmetry measures of muscle function to subjective function. Patients who were more than 5 years after ACLR exhibited strong associations between hopping symmetry and subjective function.

CLINICAL RELEVANCE

Future clinical guidelines for patients after ACLR may need to consider time since surgery as a potential factor.

Performance: Bridging the Gap After ACL Surgery

PURPOSE OF REVIEW

The purpose of this paper is to identify strategies for a successful transition to sports in patients following rehabilitation for ACL reconstruction surgery (ACLR).

RECENT FINDINGS

Recent research continues to demonstrate a relatively low rate of return to previous level of play among athletes following ACLR combined with a significant risk of injury to either the ipsi or the contralateral ACL. Recent research also demonstrates a growing use of a varied battery of assessments to determine readiness to return to sport as well as a lack of consensus on the ideal rehabilitation program, the criteria for clearance for return to play (both in time from surgery and functional milestones), and the nature of a conditioning program designed specifically for transitioning the cleared athlete back to competition. Due to the lack of consensus and consistency regarding rehabilitation protocols and criteria for clearance to play after ACLR, deficits in strength, neuromuscular control, and psychological readiness may exist in "cleared" athletes. These deficits may not only negatively impact sports performance but also raise the risk of re-injury. Programs designed to successfully return an athlete to previous level of play should include not only strength and conditioning aimed at restoring fitness that was compromised as a result of the injury but also include attention to psychological readiness and address deficits in neuromuscular control. Problems that exist following ACLR cannot be solved by one professional; successful rehabilitation and return to play require a coordinated effort among the surgeon, physical therapist, athletic trainer, and fitness professional. Future research is needed to determine the optimal strategy to restore the neuromuscular control, functional strength, and psychological readiness necessary for a successful return to competition following ACLR.

Graft Diameter as a Predictor for Revision Anterior Cruciate Ligament Reconstruction and KOOS and EQ-5D Values: A Cohort Study From the Swedish National Knee Ligament Register Based on 2240 Patients

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction (ACLR) using a hamstring tendon (HT) autograft is an effective and widespread method. Recent studies have identified a relationship between the graft diameter and revision ACLR.

PURPOSE

To evaluate the influence of the graft diameter on revision ACLR and patient-reported outcomes in patients undergoing primary ACLR using HT autografts.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A prospective cohort study was conducted using the Swedish National Knee Ligament Register (SNKLR) involving all patients undergoing primary ACLR using HT autografts. Patients with graft failure who needed revision surgery (cases) were compared with patients not undergoing revision surgery (controls). The control group was matched for sex, age, and graft fixation method in a 3:1 ratio. Conditional logistic regression was performed to produce odds ratios and 95% CIs. Univariate linear regression analyses were performed for patient-related outcomes. The Knee injury and Osteoarthritis Outcome Score (KOOS) and EuroQol 5 dimensions questionnaire (EQ-5D) values were obtained.

RESULTS

A total of 2240 patients were included in which there were 560 cases and 1680 controls. No significant differences between the cases and controls were found for sex (52.9% male), mean age (21.7 years), and femoral and tibial fixation. The mean graft diameter for the cases was 8.0 ± 0.74 mm and for the controls was 8.1 ± 0.76 mm. In the present cohort, the likelihood of revision surgery for every 0.5-mm increase in the HT autograft diameter between 7.0 and 10.0 mm was 0.86 (95% CI, 0.75-0.99; P = .03). Univariate linear regression analysis found no significant regression coefficient for the change in KOOS or EQ-5D values.

CONCLUSION

In a large cohort of patients after primary ACLR with HT autografts, an increase in the graft diameter between 7.0 and 10.0 mm resulted in a 0.86 times lower likelihood of revision surgery with every 0.5-mm increase. This study provides further evidence of the importance of the HT autograft size in intraoperative decision making.

Criteria for Return to Sport after Anterior Cruciate Ligament reconstruction with lower reinjury risk (CR'STAL study): protocol for a prospective observational study in France

INTRODUCTION

The decision regarding when to return to sport after an anterior cruciate ligament reconstruction (ACLR) is an important one. Using a variety of subjective and objective parameters, various attempts have been made to determine an optimal timeline for a return to sport after ACLR, but none have been validated.The aim of the present study is therefore to determine which criteria or combination of criteria could allow to return to sport with the lowest possible risk of reinjury.

METHODS AND ANALYSIS

This study is a prospective cohort, single-centre study, with repeated assessments at 6, 9 and 12 months post-ACL surgical reconstruction and including a 3-year follow-up of patients' sporting activity and reinjuries. 275 patients will be included to test explanatory variables. Postural control analysis, knee laxity, questionnaires (International Knee Documentation Committee (IKDC), Tampa Scale of Kinesiophobia-11 (TSK-11), Anterior Cruciate Ligament-Return to Sport After Reinjury (ACL-RSI) and Single Assessment Numeric Evaluation (SANE)), modified Star Excursion Balance Test, running and sprinting biomechanics, Hop Tests and Isokinetic Tests will all be used. The primary outcome will be any reinjury during the follow-up period, defined as a graft rupture, a contralateral ACL rupture or any injury necessitating an interruption of training and requiring a medical consultation. Two groups will be constituted during the follow-up, separating reinjured from non-reinjured patients. In addition, classic analysis and data mining approaches will be used to build predictive models.

ETHICS AND DISSEMINATION

The results of this study will be disseminated through peer-reviewed publications and scientific presentations. Ethical approval was obtained through the ethics committee of the University Hospital of Saint-Etienne (reference number IRBN522015/CHUSTE).

On-Ice Return-to-Hockey Progression After Anterior Cruciate Ligament Reconstruction

Synopsis The literature pertaining to the rehabilitation of ice hockey players seeking to return to sport after anterior cruciate ligament reconstruction (ACLR) is currently limited. The purpose of this clinical commentary was to present a criterion-based progression for return to ice hockey for athletes after ACLR. First, we review pertinent literature and provide previously published guidelines on general rehabilitation after ACLR. Then, we present a 4-phase, on-ice skating progression with objective criteria to initiate each phase. During the early on-ice phase, the athlete is reintroduced to specific demands, including graded exposure to forward, backward, and crossover skating. In the intermediate on-ice phase, the emphasis shifts to developing power and introducing anticipated changes of direction within a controlled environment. During the late on-ice phase, the focus progresses to developing anaerobic endurance and introducing unanticipated changes of direction, but still without other players or contact. Finally, once objective return-to-sport criteria are met, noncontact team drills, outnumbered and even-numbered drills, practices, scrimmages, and games are progressively reintroduced during the return-to-sport phase. Recommendations for off-ice strength and conditioning exercises complement the on-ice progression. Additionally, we apply the return-to-hockey progression framework to a case report of a female collegiate defensive ice hockey player who returned to sport successfully after ACLR. This criterion-based return-to-hockey progression may guide rehabilitation specialists managing athletes returning to ice hockey after ACLR. J Orthop Sports Phys Ther 2017;47(5):324-333. Epub 29 Mar 2017. doi:10.2519/jospt.2017.7245.

Limb Symmetry Indexes Can Overestimate Knee Function After Anterior Cruciate Ligament Injury

Study Design Prospective cohort. Background The high risk of second anterior cruciate ligament (ACL) injuries after return to sport highlights the importance of return-to-sport decision making. Objective return-to-sport criteria frequently use limb symmetry indexes (LSIs) to quantify quadriceps strength and hop scores. Whether using the uninvolved limb in LSIs is optimal is unknown. Objectives To evaluate the uninvolved limb as a reference standard for LSIs utilized in return-to-sport testing and its relationship with second ACL injury rates. Methods Seventy athletes completed quadriceps strength and 4 single-leg hop tests before anterior cruciate ligament reconstruction (ACLR) and 6 months after ACLR. Limb symmetry indexes for each test compared involved-limb measures at 6 months to uninvolved-limb measures at 6 months. Estimated preinjury capacity (EPIC) levels for each test compared involved-limb measures at 6 months to uninvolved-limb measures before ACLR. Second ACL injuries were tracked for a minimum follow-up of 2 years after ACLR. Results Forty (57.1%) patients achieved 90% LSIs for quadriceps strength and all hop tests. Only 20 (28.6%) patients met 90% EPIC levels (comparing the involved limb at 6 months after ACLR to the uninvolved limb before ACLR) for quadriceps strength and all hop tests. Twenty-four (34.3%) patients who achieved 90% LSIs for all measures 6 months after ACLR did not achieve 90% EPIC levels for all measures. Estimated preinjury capacity levels were more sensitive than LSIs in predicting second ACL injuries (LSIs, 0.273; 95% confidence interval [CI]: 0.010, 0.566 and EPIC, 0.818; 95% CI: 0.523, 0.949). Conclusion Limb symmetry indexes frequently overestimate knee function after ACLR and may be related to second ACL injury risk. These findings raise concern about whether the variable ACL return-to-sport criteria utilized in current clinical practice are stringent enough to achieve safe and successful return to sport. Level of Evidence Prognosis, 2b. J Orthop Sports Phys Ther 2017;47(5):334-338. Epub 29 Mar 2017. doi:10.2519/jospt.2017.7285.

Return to Sport in the Younger Patient With Anterior Cruciate Ligament Reconstruction

Background:

Although anterior cruciate ligament (ACL) reconstruction is generally regarded as a successful procedure, only 65% of patients return to their preinjury sport. While return-to-sport rates are likely higher in younger patients, there is a paucity of data that focus on the younger patient and their return-to-sport experience after ACL reconstruction.

Purpose:

To investigate a range of return-to-sport outcomes in younger athletes who had undergone ACL reconstruction surgery.

Study Design:

Case series; Level of evidence, 4.

Methods:

A group of 140 young patients (<20 years old at surgery) who had 1 ACL reconstruction and no subsequent ACL injuries completed a survey regarding details of their sport participation at a mean follow-up of 5 years (range, 3-7 years).

Results:

Overall, 76% (95% CI, 69%-83%) of the young patient group returned to the same preinjury sport. Return rates were higher for males than females (81% vs 71%, respectively; P > .05). Of those who returned to their sport, 65% reported that they could perform as well as before the ACL injury and 66% were still currently participating in their respective sport. Young athletes who never returned to sport cited fear of a new injury (37%) or study/work commitments (30%) as the primary reasons for dropout. For those who had successfully returned to their preinjury sport but subsequently stopped participating, the most common reason cited for stopping was study/work commitments (53%). At a mean 5-year follow-up, 48% of female patients were still participating in level I (jumping, hard pivoting) sports, as were 54% of males.

Conclusion:

A high percentage of younger patients return to their preinjury sport after ACL reconstruction surgery. For patients in this cohort who had not sustained a second ACL injury, the majority continue to participate and are satisfied with their performance.

Do Patients Failing Return-to-Activity Criteria at 6 Months After Anterior Cruciate Ligament Reconstruction Continue Demonstrating Deficits at 2 Years?

BACKGROUND

The variability in outcomes after anterior cruciate ligament reconstruction (ACLR) might be related to the criteria that are used to determine athletes' readiness to return to their preinjury activity level. A battery of return-to-activity criteria (RTAC) that emphasize normal knee function and movement symmetry has been instituted to quantitatively determine athletes' readiness to return to preinjury activities.

PURPOSE

To investigate performance-based and patient-reported measures at 12 and 24 months after ACLR between patients who passed or failed RTAC at 6 months after ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 108 patients who had participated in International Knee Documentation Committee level 1 or 2 sports activities completed RTAC testing at 6, 12, and 24 months after surgery. The RTAC included the isometric quadriceps strength index (QI), 4 single-legged hop tests, the Knee Outcome Survey-activities of daily living subscale (KOS-ADLS), and the global rating scale of perceived function (GRS). Patients who scored ≥90% on all RTAC were classified as the pass group, and those who scored <90% on any RTAC were classified as the fail group. At 12- and 24-month follow-ups, patients were asked if they had returned to the same preinjury activity level.

RESULTS

At the 6-month follow-up, there were 48 patients in the pass group and 47 in the fail group. At the 12-month follow-up, 31 patients (73.8%) from the pass group and 15 patients (39.5%) from the fail group passed RTAC, and at the 24-month follow-up, 25 patients (75.8%) from the pass group and 14 patients (51.9%) from the fail group passed RTAC. The rate of return to activities in the pass group was 81% and 84% at 12 and 24 months after ACLR, respectively, compared with only 44% and 46% in the fail group ( P ≤ .012), respectively; however, some patients in the fail group participated in preinjury activities without being cleared by their therapists. At 12 and 24 months, 60.5% and 48.1% of patients continued to fail again on the criteria, respectively. A statistically significant group × time interaction was found for the single hop and 6-m timed hop limb symmetry indices (LSIs) ( P ≤ .037), with only the fail group demonstrating a significant improvement over time. A main effect of group was detected for the QI and the crossover hop and triple hop LSIs ( P < .01), with patients in the pass group demonstrating higher performance. A main effect of time was detected for the crossover hop and triple hop LSIs and the GRS, with improvements seen in both groups ( P < .05).

CONCLUSION

Patients who passed the RTAC early after ACLR were more likely to demonstrate normal knee function and movement symmetry at 12 and 24 months postoperatively, while patients who failed the RTAC early were more likely to demonstrate impaired knee function and movement asymmetry at 12- and 24-month follow-ups. Patients in the pass group had a higher rate of return to their preinjury activity level compared with those in the fail group. A group of patients chose to return to their preinjury activities, even though they were functionally not ready.

Two-Year Outcomes of a Randomized Trial Investigating a 6-Week Return to Full Weightbearing After Matrix-Induced Autologous Chondrocyte Implantation

BACKGROUND

Matrix-induced autologous chondrocyte implantation (MACI) has demonstrated encouraging outcomes in treating patients with knee cartilage defects. Postoperatively, the time required to attain full weightbearing (WB) remains conservative.

HYPOTHESIS

We hypothesized that patients would have no significant clinical or radiological differences or graft complications after an 8-week or 6-week return to full WB after MACI.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 37 knees (n = 35 patients) were randomly allocated to either an 8-week return to full WB that we considered current best practice based on the existing literature (CR group; n = 19 knees) or an accelerated 6-week WB approach (AR group; n = 18 knees). Patients were evaluated preoperatively and at 1, 2, 3, 6, 12, and 24 months after surgery, using the Knee Injury and Osteoarthritis Outcome Score, 36-Item Short Form Health Survey, visual analog pain scale, 6-minute walk test, and active knee range of motion. Isokinetic dynamometry was used to assess peak knee extension and flexion strength and limb symmetry indices (LSIs) between the operated and nonoperated limbs. Magnetic resonance imaging (MRI) was undertaken to evaluate the quality and quantity of repair tissue as well as to calculate an MRI composite score.

RESULTS

Significant improvements ( P < .05) were observed in all subjective scores, active knee flexion and extension, 6-minute capacity, peak knee extensor torque in the operated limb, and knee extensor LSI, although no group differences existed. Although knee flexor LSIs were above 100% for both groups at 12 and 24 months after surgery, LSIs for knee extensor torque at 24 months were 93.7% and 87.5% for the AR and CR groups, respectively. The MRI composite score and pertinent graft parameters significantly improved over time ( P < .05), with some superior in the AR group at 24 months. All patients in the AR group (100%) demonstrated good to excellent infill at 24 months, compared with 83% of patients in the CR group. Two cases of graft failure were observed, both in the CR group. At 24 months, 83% of patients in the CR group and 88% in the AR group were satisfied with the results of their MACI surgery.

CONCLUSION

Patients in the AR group who reduced the length of time spent ambulating on crutches produced comparable outcomes up to 24 months, without compromising graft integrity.

Trajectory of self-reported pain and function and knee extensor muscle strength in young patients undergoing arthroscopic surgery for meniscal tears: A systematic review and meta-analysis

OBJECTIVES

To investigate the trajectory of patient reported pain and function and knee extensor muscle strength over time in young individuals undergoing arthroscopic meniscal surgery.

DESIGN

Systematic review and meta-analysis METHODS: Six databases were searched up to October 13th, 2016.

PATIENTS AND INTERVENTION

People aged 30 years or younger undergoing surgery for a meniscal tear.

OUTCOMES

and comparator: (1) Self-reported pain and function in patients undergoing meniscal surgery compared to a non-operative control group (2). Knee extensor strength in the leg undergoing surgery compared to a healthy control group or the contra-lateral leg. Methodological quality was assessed using the SIGN 50 guidelines.

RESULTS

No studies were found on patient reported pain and function. Six studies, including 137 patients were included in the analysis on knee extensor muscle strength. Knee extensor muscle strength was impaired in the injured leg prior to surgery and was still reduced compared with control data up to 12 months after surgery (SMD: -1.16) (95% CI: -1.83; -0.49). All included studies were assessed to have a high risk of bias.

CONCLUSIONS

No studies were found comparing the trajectory of self-reported pain and function in patients undergoing arthroscopic surgery compared with non-operative treatments for young patients with meniscal tears. Knee extensor strength seemed to be impaired up to 12 months after surgery in young patients undergoing surgery for meniscal tears. The results of the present study should be interpreted with caution due to a limited number of available studies with high risk of bias including relatively few patients.

Diagnostic Accuracy of Handheld Dynamometry and 1-Repetition-Maximum Tests for Identifying Meaningful Quadriceps Strength Asymmetries

Study Design Clinical measurement, cross-sectional. Background Quadriceps deficits are common in individuals with knee joint impairments and impact functional and quality-of-life outcomes. Quadriceps strength symmetry influences clinical decisions after knee injury. Isometric electromechanical dynamometry (ISO-ED) is the gold standard for measuring symmetry, but is not available in all clinical settings. Objectives To compare concurrent validity of handheld dynamometry and 1-repetition-maximum leg press, knee extension from 90° to 0°, and knee extension from 90° to 45° to that of ISO-ED in identifying meaningful quadriceps strength deficits. Methods Fifty-six participants with knee joint impairments completed ISO-ED and 4 alternative measures of quadriceps strength symmetry in a single session. Absolute agreement of alternative measures with ISO-ED was calculated with intraclass correlation coefficients (ICCs). Clinical agreement values at thresholds of 80% and 90% symmetry were compared between the alternatives and ISO-ED. Results Knee extension from 90° to 45° (ICC = 0.67) and handheld dynamometry (ICC = 0.70) had the greatest ICCs. Clinical agreement was also best for these measures for 80% symmetry (κ = 0.56 and 0.55, respectively) and 90% symmetry (κ = 0.19 and 0.33, respectively). Conclusion Handheld dynamometry and 1-repetition-maximum testing of knee extension from 90° to 45° are fair alternatives, although symmetry is typically overestimated. Receiver operating characteristic analysis identified alternative measure thresholds that correlated with the 80% and 90% symmetry thresholds on the ISO-ED. Clinicians should use more stringent symmetry values for these alternative tests to increase the probability that individuals have a minimum ISO-ED symmetry of 80% or 90%. J Orthop Sports Phys Ther 2017;47(2):97-107. doi:10.2519/jospt.2017.6651.

Knee function among elite handball and football players 1-6 years after anterior cruciate ligament injury

The aim of the study was to describe objective and self-reported knee function for athletes who have returned to elite handball and football play after an ACL injury, comparing these to non-injured players at the same level. A total of 414 handball and 444 football players completed baseline tests from 2007 through 2014, examining lower extremity strength, dynamic balance, knee laxity, and knee function (KOOS questionnaire). Measures were compared between injured and non-injured legs and between injured legs and legs of controls. Eighty (9.3%) of the 858 players reported a previous ACL injury, 1-6 years post-injury (3.5±2.5 years), 49 handball (61.3%) and 31 football players (38.7%). We found no difference in strength or dynamic balance between previously ACL-injured (N=80) and non-injured players legs (N=1556). However, lower quadriceps (6.3%, 95% CI: 3.2-9.2) and hamstrings muscle strength (6.1%, 95% CI: 3.3-8.1) were observed in previously ACL-injured legs compared to the non-injured contralateral side (N=80). ACL-injured knees displayed greater joint laxity than the contralateral knee (N=80, 17%, 95% CI: 8-26) and healthy knees (N=1556, 23%, 95% CI: 14-33). KOOS scores were significantly lower for injured knees compared to knees of non-injured players. ACL-injured players who have successfully returned to elite sport have comparable strength and balance measures as their non-injured teammates. Subjective perception of knee function is strongly affected by injury history, with clinically relevant lower scores for the KOOS subscores Pain, Function, Sport, and Quality Of Life.

No differences in subjective knee function between surgical techniques of anterior cruciate ligament reconstruction at 2-year follow-up: a cohort study from the Swedish National Knee Ligament Register

PURPOSE

The purpose of this study was to investigate how different techniques of single-bundle anterior cruciate ligament (ACL) reconstruction affect subjective knee function via the Knee injury and Osteoarthritis Outcome Score (KOOS) evaluation 2 years after surgery. It was hypothesized that the surgical techniques of single-bundle ACL reconstruction would result in equivalent results with respect to subjective knee function 2 years after surgery.

METHODS

This cohort study was based on data from the Swedish National Knee Ligament Register during the 10-year period of 1 January 2005 through 31 December 2014. Patients who underwent primary single-bundle ACL reconstruction with hamstrings tendon autograft were included. Details on surgical technique were collected using a web-based questionnaire comprised of essential AARSC items, including utilization of accessory medial portal drilling, anatomic tunnel placement, and visualization of insertion sites and landmarks. A repeated measures ANOVA and an additional linear mixed model analysis were used to investigate the effect of surgical technique on the KOOS₄ from the pre-operative period to 2-year follow-up.

RESULTS

A total of 13,636 patients who had undergone single-bundle ACL reconstruction comprised the study group for this analysis. A repeated measures ANOVA determined that mean subjective knee function differed between the pre-operative time period and at 2-year follow-up (p < 0.001). No differences were found with respect to the interaction between KOOS₄ and surgical technique or gender. Additionally, the linear mixed model adjusted for age at reconstruction, gender, and concomitant injuries showed no difference between surgical techniques in KOOS₄ improvement from baseline to 2-year follow-up. However, KOOS₄ improved significantly in patients for all surgical techniques of single-bundle ACL reconstruction (p < 0.001); the largest improvement was seen between the pre-operative time period and at 1-year follow-up.

CONCLUSION

Surgical techniques of primary single-bundle ACL reconstruction did not demonstrate differences in the improvement in baseline subjective knee function as measured with the KOOS₄ during the first 2 years after surgery. However, subjective knee function improved from pre-operative baseline to 2-year follow-up independently of surgical technique.

Development of a test battery to enhance safe return to sports after anterior cruciate ligament reconstruction

PURPOSE

There is a lack of consensus regarding the appropriate criteria for releasing patients to return to sports (RTS) after anterior cruciate ligament reconstruction (ACLR). A test battery was developed to support decision-making.

METHODS

Twenty-eight patients (22 males and 6 females) with a mean age of 25.4 ± 8.2 years participated and were 6.5 ± 1.0 months post-ACLR. All patients followed the same rehabilitation protocol. The test battery used consisted of the following: isokinetic test, 3 hop tests and the jump-landing task assessed with the LESS. The isokinetic tests and single-leg hop tests were expressed as a LSI (involved limb/uninvolved limb × 100 %). In addition, patients filled out the IKDC and ACL-Return to Sport after Injury (ACL-RSI) scale. RTS criteria to pass were defined as a LSI > 90 % on isokinetic and hop tests, LESS < 5, ACL-RSI > 56 and a IKDC within 15th percentile of healthy subjects.

RESULTS

Two out of 28 patients passed all criteria of the test protocol. The pass criterion for the LESS < 5 was reached by 67.9 % of all patients. For the hop tests, 78.5 % of patients passed LSI > 90 % for SLH, 85.7 % for TLH and 50 % for the SH. For the isokinetic test, 39.3 % of patients passed criteria for LSI peak torque quadriceps at 60°/s, 46.4 % at 180°/s and 42.9 at 300°/s. In total, 35.7 % of the patients passed criterion for the peak torque at 60°/s normalized to BW (>3.0 Nm) for the involved limb. The H/Q ratio at 300°/s > 55 % for females was achieved by 4 out of 6 female patients, and the >62.5 % criterion for males was achieved by 75 %. At 6 months post-ACLR, 85.7 % of the patients passed the IKDC score and 75 % the ACL-RSI score >56 criteria.

CONCLUSION

The evidence emerging from this study suggests that the majority of patients who are 6 months after ACLR require additional rehabilitation to pass RTS criteria. The RTS battery described in this study may serve as a framework for future studies to implement multivariate models in order to optimize the decision-making regarding RTS after ACLR with the aim to reduce incidence of second ACL injuries.

LEVEL OF EVIDENCE

III.

IMPROVEMENTS IN KNEE EXTENSION STRENGTH ARE ASSOCIATED WITH IMPROVEMENTS IN SELF-REPORTED HIP FUNCTION FOLLOWING ARTHROSCOPY FOR FEMOROACETABULAR IMPINGEMENT SYNDROME

BACKGROUND

Recovery of strength is critical for return to sport, and is a known predictor of functional outcomes in post-surgical orthopedic populations. Muscle weakness is a known impairment in patients with femoroacetabular impingement syndrome (FAIS) but whether improvements in muscle strength after arthroscopy are associated with improved hip function is unknown.

HYPOTHESIS/PURPOSE

To examine the relationships between changes in hip and thigh muscle strength and self-reported function in athletes undergoing arthroscopy for FAIS.

STUDY DESIGN

Single cohort descriptive and correlational study.

METHODS

Twenty-eight athletes underwent strength testing and completed the Hip Outcome Score Activities of Daily Living (HOS-ADL) and Sports (HOS-S) subscales prior to and six months after surgery. Isokinetic knee extension and flexion strength were measured using a Biodex dynamometer at 60 °/s and 300 °/s. Isometric hip abduction strength was measured using a custom dynamometer. Changes in strength, limb symmetry, and HOS scores were assessed using paired t-tests. Spearman's rank correlations were used to examine relationships between change in involved limb strength and change in HOS scores.

RESULTS

Subjects were tested an average of 32 days before and 178 days after surgery. HOS-ADL and HOS-S subscales improved by a mean of 19.0 ± 21.1 and 23.8 ± 31.9, respectively, over time (p < 0.001). Hip abduction strength did not increase over time in either limb (p ≥ 0.27). Involved limb knee flexion and extension strength did not increase significantly over time (p-values: 0.10-0.48) with the exception of knee extension at 300 °/s (p = 0.04). Uninvolved limb knee extension strength at both velocities and knee flexion strength at 60 °/s improved significantly over time (p < 0.012). Increases in knee extension strength (60 °/s) of the involved limb were significantly correlated with improvements on the HOS-ADL (r = 0.431; 0 = 0.025) and HOS-S (r = 0.439; p = 0.025). There were no significant relationships between changes in involved limb hip abduction or knee flexion strength and HOS subscales (p≥0.123).

CONCLUSION

Improvements in knee extension strength were associated with improvements in self-reported hip function in athletes following arthroscopy for FAIS. Individuals with knee extension strength deficits prior to surgery may benefit from targeted knee extension strengthening during post-operative rehabilitation to improve functional outcomes.

LEVEL OF EVIDENCE

Level III (non-randomized controlled cohort study).