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Some individuals can stabilize their knees following anterior cruciate ligament rupture even during activities involving cutting and pivoting (copers), others have instability with daily activities (non-copers). Movement and muscle activation patterns of 11 copers, ten non-copers and ten uninjured subjects were studied during walking and jogging. Results indicate that distinct gait adaptations appeared primarily in the non-copers. Copers used joint ranges of motion, moments and muscle activation patterns similar to uninjured subjects. Non-copers reduced their knee motion, and external knee flexion moments that correlated well with quadriceps strength. Non-copers also achieved peak hamstring activity later in the weight acceptance phase and used a strategy involving more generalized co-contraction. Both copers and non-copers had high levels of quadriceps femoris muscle activity. The reduced knee moment in the involved limbs of the non-copers did not represent "quadriceps avoidance" but rather represented a strategy of general co-contraction with a greater relative contribution from the hamstring muscles. [ABSTRACT FROM AUTHOR]

Abstract Background Arthritis is a leading cause of disability in the United States. Total knee arthroplasty (TKA) has become the gold standard to manage the pain and disability associated with knee osteoarthritis (OA). Although more than 400 000 primary TKA surgeries are performed each year in the United States, not all individuals with knee OA elect to undergo the procedure. No clear consensus exists on criteria to determine who should undergo TKA. The purpose of this study was to determine which clinical factors will predict the decision to undergo TKA in individuals with end-stage knee OA. Knowledge of these factors will aid in clinical decision making for the timing of TKA. Methods Functional data from one hundred twenty persons with end-stage knee OA were obtained through a database. All of the individuals complained of knee pain during daily activities and had radiographic evidence of OA. Functional and clinical tests, collectively referred to as the Delaware Osteoarthritis Profile, were completed by a physical therapist. This profile consisted of measuring height, weight, quadriceps strength and active knee range of motion, while functional mobility was assessed using the Timed Up and Go (TUG) test and the Stair Climbing Task (SCT). Self-perceived functional ability was measured using the activities of daily living subscale of the Knee Outcome Survey (KOS-ADLS). A logistic regression model was used to identify variables predictive of TKA use. Results Forty subjects (33%) underwent TKA within two years of evaluation. These subjects were significantly older and had significantly slower TUG and SCT times (p < 0.05). Persons that underwent TKA were also significantly weaker, had lower self-reported function and had less knee extension than persons who did not undergo TKA. No differences between groups were seen for BMI, gender, knee flexion ROM and unilateral versus bilateral joint disease. Using backward regression, age, knee extension ROM and KOS-ADLS together significantly predicted whether or not a person would undergo TKA (p ≤ 0.001, R2 = 0.403). Conclusions Younger patients with full knee ROM who have a higher self-perception of function are less likely to undergo TKA. Physicians and clinicians should be aware that potentially modifiable factors, such as knee ROM can be addressed to potentially postpone the need for TKA.

Intra-articular corticosteroid injections, such as triamcinolone acetonide (TA), are commonly used by clinicians to manage joint synovial inflammation. However, due to conflicting evidence in literature, there is a fear among clinicians that the injections may be harmful to otherwise healthy cartilage in young patients. The purpose of this study was to evaluate the effects of TA on young, healthy chondrocytes. Articular cartilage samples were harvested from bovine knee joints (1-2 months old). In both healthy and inflammatory (interleukin-1β) challenged cartilage, samples were treated with TA at doses ranging from 1 nM to 200 μM. Following a short- (2 days) or long-term (10-14 days) treatment, chondrocyte viability, proliferation, and extracellular matrix (ECM) synthesis and degradation were evaluated with a click chemistry-based technique. Chondrocyte viability, proliferation, and anabolic activity were all minimally affected by short-term and long-term TA treatment. After both acute and sustained inflammatory challenges, TA reduced the catabolic activities in cartilage, reducing nascent glycosaminoglycan loss and maintaining cartilage mechanical properties. Overall, at physiologically relevant doses, TA had minimal negative impact on chondrocytes when maintained within their native ECM. Clinical significance: The findings provide new insight for current clinical practices concerning the use of TA in intra-articular injections, especially in young patients, and established a foundation for future investigations into the impact of corticosteroids on joint homeostasis., (© 2024 Orthopaedic Research Society.)

Background: Monoclonal antibodies (mAb) that neutralize SARS-CoV-2 decrease hospitalization and death compared to placebo in patients with mild to moderate COVID-19; however, comparative effectiveness is unknown. We report the comparative effectiveness of bamlanivimab, bamlanivimab-etesevimab, and casirivimab-imdevimab., Methods: A learning health system platform trial in a U.S. health system enrolled patients meeting mAb Emergency Use Authorization criteria. An electronic health record-embedded application linked local mAb inventory to patient encounters and provided random mAb allocation. Primary outcome was hospital-free days to day 28. Primary analysis was a Bayesian model adjusting for treatment location, age, sex, and time. Inferiority was defined as 99% posterior probability of an odds ratio < 1. Equivalence was defined as 95% posterior probability the odds ratio is within a given bound., Findings: Between March 10 and June 25, 2021, 1935 patients received treatment. Median hospital-free days were 28 (IQR 28, 28) for each mAb. Mortality was 0.8% (1/128), 0.8% (7/885), and 0.7% (6/922) for bamlanivimab, bamlanivimab-etesevimab, and casirivimab-imdevimab, respectively. Relative to casirivimab-imdevimab (n = 922), median adjusted odds ratios were 0.58 (95% credible interval [CI] 0.30-1.16) and 0.94 (95% CI 0.72-1.24) for bamlanivimab (n = 128) and bamlanivimab-etesevimab (n = 885), respectively. These odds ratios yielded 91% and 94% probabilities of inferiority of bamlanivimab versus bamlanivimab-etesevimab and casirivimab-imdevimab, and an 86% probability of equivalence between bamlanivimab-etesevimab and casirivimab-imdevimab., Interpretation: Among patients with mild to moderate COVID-19, bamlanivimab-etesevimab or casirivimab-imdevimab treatment resulted in 86% probability of equivalence. No treatment met prespecified criteria for statistical equivalence. Median hospital-free days to day 28 were 28 (IQR 28, 28) for each mAb., Funding and Registration: This work received no external funding. The U.S. government provided the reported mAb. This trial is registered at ClinicalTrials.gov, NCT04790786., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Importance: The effectiveness of monoclonal antibodies (mAbs), casirivimab-imdevimab and sotrovimab, is unknown in patients with mild to moderate COVID-19 caused by the SARS-CoV-2 Delta variant., Objective: To evaluate the effectiveness of mAb against the Delta variant compared with no mAb treatment and to ascertain the comparative effectiveness of casirivimab-imdevimab and sotrovimab., Design, Setting, and Participants: This study comprised 2 parallel studies: (1) a propensity score-matched cohort study of mAb treatment vs no mAb treatment and (2) a randomized comparative effectiveness trial of casirivimab-imdevimab and sotrovimab. The cohort consisted of patients who received mAb treatment at the University of Pittsburgh Medical Center outpatient infusion centers and emergency departments from July 14 to September 29, 2021. Participants were patients with a positive SARS-CoV-2 test result who were eligible to receive mAbs according to emergency use authorization criteria., Exposure: For the trial, patients were randomized to either intravenous casirivimab-imdevimab or sotrovimab according to a system therapeutic interchange policy., Main Outcomes and Measures: For the cohort study, risk ratio (RR) estimates for the primary outcome of hospitalization or death by 28 days were compared between mAb treatment and no mAb treatment using propensity score-matched models. For the comparative effectiveness trial, the primary outcome was hospital-free days (days alive and free of hospitalization) within 28 days after mAb treatment, where patients who died were assigned -1 day in a bayesian cumulative logistic model adjusted for treatment location, age, sex, and time. Inferiority was defined as a 99% posterior probability of an odds ratio (OR) less than 1. Equivalence was defined as a 95% posterior probability that the OR was within a given bound., Results: A total of 3069 patients (1023 received mAb treatment: mean [SD] age, 53.2 [16.4] years; 569 women [56%]; 2046 had no mAb treatment: mean [SD] age, 52.8 [19.5] years; 1157 women [57%]) were included in the prospective cohort study, and 3558 patients (mean [SD] age, 54 [18] years; 1919 women [54%]) were included in the randomized comparative effectiveness trial. In propensity score-matched models, mAb treatment was associated with reduced risk of hospitalization or death (RR, 0.40; 95% CI, 0.28-0.57) compared with no treatment. Both casirivimab-imdevimab (RR, 0.31; 95% CI, 0.20-0.50) and sotrovimab (RR, 0.60; 95% CI, 0.37-1.00) were associated with reduced hospitalization or death compared with no mAb treatment. In the clinical trial, 2454 patients were randomized to receive casirivimab-imdevimab and 1104 patients were randomized to receive sotrovimab. The median (IQR) hospital-free days were 28 (28-28) for both mAb treatments, the 28-day mortality rate was less than 1% (n = 12) for casirivimab-imdevimab and less than 1% (n = 7) for sotrovimab, and the hospitalization rate by day 28 was 12% (n = 291) for casirivimab-imdevimab and 13% (n = 140) for sotrovimab. Compared with patients who received casirivimab-imdevimab, those who received sotrovimab had a median adjusted OR for hospital-free days of 0.88 (95% credible interval, 0.70-1.11). This OR yielded 86% probability of inferiority for sotrovimab vs casirivimab-imdevimab and 79% probability of equivalence., Conclusions and Relevance: In this propensity score-matched cohort study and randomized comparative effectiveness trial, the effectiveness of casirivimab-imdevimab and sotrovimab against the Delta variant was similar, although the prespecified criteria for statistical inferiority or equivalence were not met. Both mAb treatments were associated with a reduced risk of hospitalization or death in nonhospitalized patients with mild to moderate COVID-19 caused by the Delta variant., Trial Registration: ClinicalTrials.gov Identifier: NCT04790786.

Outpatient treatments that limit progression to severe coronavirus disease 2019 (COVID-19) are of vital importance to optimise patient outcomes and public health. Monoclonal antibodies (mAb) demonstrated ability to decrease hospitalizations in randomized, clinical trials. However, there are many barriers to mAb treatment such as patient access and clinician education. There are no data comparing efficacy or safety of available mAbs. We sought to rapidly launch an adaptive platform trial with the goals of enhancing access to treatment, regardless of geography and socioeconomic status, and evaluating comparative efficacy and safety of available mAbs. Within 21 days from idea genesis, we allocated mAb treatment to all patients within the context of this clinical trial. Within 2 months, we closed the gap of the likelihood of receiving mAb, conditional on background positivity rate, between Black and White patients (Black patients 0.238; White patients 0.241). We describe trial infrastructure, lessons learned, and future directions for a culture of learning while doing., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Antigen testing offers rapid and inexpensive testing for SARS-CoV-2 but concerns regarding performance, especially sensitivity, remain. Limited data exists for use of antigen testing in asymptomatic patients; thus, performance and reliability of antigen testing remains unclear., Methods: 148 symptomatic and 144 asymptomatic adults were included. A nasal swab was collected for testing by Quidel Sofia SARS IFA (Sofia) as point of care. A nasopharyngeal swab was also collected and transported to the laboratory for testing by Cepheid Xpert Xpress SARS-CoV-2/Flu/RSV RT-PCR (Cepheid)., Results: Overall, Sofia had good agreement with Cepheid (> 95%) in adults, however was less sensitive. Sofia had a sensitivity of 87.8% and 33.3% for symptomatic and asymptomatic patients, respectively. Among symptomatic patients, testing > 5 days post symptom onset resulted in lower sensitivity (82%) when compared with testing within 5 days of symptom onset (90%). Of the four Sofia false-negative results in the asymptomatic cohort, 50% went on to develop COVID-19 disease within 5 days of testing. Specificity in both symptomatic and asymptomatic cohorts was 100%., Conclusions: Sofia has acceptable performance in symptomatic adults when tested < 5 days of symptom onset. Caution should be taken when testing patients with ≥ 5 days of symptoms. The combination of low prevalence and reduced sensitivity results in relatively poor performance of in asymptomatic patients. NAAT-based diagnostic assays should be considered in when antigen testing is unreliable, particularly in symptomatic patients with > 5 days of symptom onset and asymptomatic patients., (© 2021. The Author(s).)

Objective: To elucidate the relationships between age, return to level I sport (RTS) within the first postoperative year, passing RTS criteria and second anterior cruciate ligament (ACL) injury., Methods: In a prospective cohort study, 213 athletes were followed for 2 years after ACL reconstruction to record second ACL injuries. Independent variables were age, passing RTS criteria and level I RTS within the first postoperative year (vs later or no RTS). We defined passing RTS criteria as ≥90 on the Knee Outcome Survey - Activities of Daily Living Scale, global rating scale of function and quadriceps strength/hop test symmetry., Results: The follow-up rate was >87% for all outcomes. In multivariable analysis, level I RTS within the first postoperative year and passing RTS criteria were highly associated with second ACL injury (level I RTS HR: 6.0 (95% CI: 1.6 to 22.6), pass RTS criteria HR: 0.08 (95% CI: 0.01 to 0.6)), while age was not (age HR: 0.96 (95% CI: 0.89 to 1.04)). Athletes <25 years had higher level I RTS rates in the first postoperative year (60.4%) than older athletes (28.0%). Of those who returned to level I sport in the first postoperative year, 38.1% of younger and 59.1% of older athletes passed RTS criteria., Conclusion: High rates of second ACL injury in young athletes may be driven by a mismatch between RTS rates and functional readiness to RTS. Passing RTS criteria was independently associated with a lower second ACL rate. Allowing more time prior to RTS, and improving rehabilitation and RTS support, may reduce second ACL injury rates in young athletes with ACL reconstruction., Competing Interests: Competing interests: The authors received support from the National Institute of Child Health and Human Development (NICHD; R37HD037985) and National Institute of General Medical Sciences (NIGMS; P30GM103333, U54GM104941) of the National Institutes of Health (NIH). HG and MAR received grants from the NIH during the conduct of the study. MJA received education payments from Arthrex, hospitality payments from Arthrex and Horizon Pharma and honoraria from Horizon Pharma. LE received research and fellowship grants from Arthrex and Smith & Nephew. LSM received grants from the NICHD and NIGMS during the conduct of the study., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Excessive accumulation of misfolded proteins was recently demonstrated in preeclampsia. We examined levels and activity of circulatory proteasome and immunoproteasome (inflammatory subtype) in preeclampsia and hemolysis, elevated liver enzymes, and thrombocytopenia (HELLP) syndrome. We analyzed samples from women with hypertensive pregnancy disorders (n=115), including preeclampsia with severe features (sPE) and HELLP syndrome, and normotensive controls (n=45). Plasma proteasome and immunoproteasome immunoreactivity were determined by quantifying the α-subunit of the 20S core and β5i (proteasome subunit beta 8 [PSMB8]), respectively. Plasma proteasome activity was analyzed with fluorogenic substrates. MG132, lactacystin, and ONX0914 were used to inhibit the circulating proteasome and immunoproteasome, respectively. Plasma cytokine profiles were evaluated by multiplex immunoassay. Placental expression of β5 (constitutive proteasome) and β5i (immunoproteasome) was interrogated by immunohistochemistry. Women with sPE had increased plasma 20S levels ( P<0.001) and elevated lytic activities (chymotrypsin-like 7-fold, caspase-like 4.2-fold, trypsin-like 2.2-fold; P <0.001 for all) compared with pregnant controls. Women with features of HELLP displayed the highest plasma proteasome levels and activity, which correlated with decreased IFN-γ (interferon-γ), and increased IL (interleukin)-8 and IL-10. In sPE and HELLP, chymotrypsin-like activity was suppressed by proteasome inhibitors including ONX0914. Compared with gestational age-matched controls, sPE placentas harbored increased β5 and β5i immunostaining in trophoblasts. β5i signal was elevated in HELLP with predominant staining in villous core, extravillous trophoblasts in placental islands, and extracellular vesicles in intervillous spaces. Pregnancy represents a state of increased proteostatic stress. sPE and HELLP were characterized by significant upregulation in circulating levels and lytic activity of the proteasome that was partially explained by placental immunoproteasome upregulation.

Background: Some athletes demonstrate excellent dynamic stability after anterior cruciate ligament (ACL) rupture and return to sport without ACL reconstruction (ACLR) (copers). Others demonstrate persistent instability despite rehabilitation (noncopers) and require surgical stabilization. Testing to determine coper classification can identify potential copers early after rupture. It is unclear how coper classification changes after a brief intervention and how early classification relates to long-term outcomes., Purpose: (1) To evaluate the consistency of early coper classification (potential coper vs noncoper) before and after progressive neuromuscular and strength training (NMST) among athletes early after acute ACL rupture and (2) to evaluate the association of early coper classification with 2-year success after ACL rupture., Study Design: Cohort study; Level of evidence, 2., Methods: This was a prospective analysis from the Delaware-Oslo ACL Cohort Study, composed of athletes consecutively enrolled early after ACL rupture. Participants (n = 271) were tested and classified as potential copers or noncopers according to established criteria before and after a 10-session NMST program. Success 2 years after ACLR or nonoperative rehabilitation was defined as meeting or exceeding sex- and age-matched norms for knee function, no ACL graft rupture, and ≤1 episode of giving way within the previous year. The McNemar test evaluated changes in coper classification pre- to posttraining. Logistic regression adjusted for baseline characteristics was used to evaluate the association of early coper classification and surgical status with 2-year success., Results: Of 300 athletes enrolled, 271 (90%) completed the posttraining data collection, and 219 (73%) returned for the 2-year follow-up. The coper classifications were different between time points: nearly half of those classified initially as noncopers became potential copers ( P < .001). At the 2-year follow-up, 66% of the ACLR group and 74% of the nonoperative group were successful. Athletes who were potential copers posttraining and chose ACLR or nonoperative rehabilitation had 2.7 (95% CI, 1.3-5.6) and 2.9 (95% CI, 1.2-7.2) times the odds of success, respectively, as compared with noncopers who chose ACLR., Conclusion: Coper classification improved after NMST; more athletes became potential copers. Athletes who were potential copers after NMST were more likely to succeed 2 years later regardless of whether they had surgery, strongly supporting the addition of NMST before ACLR. Persistent noncopers fared poorly, indicating that more intensive rehabilitation may be needed.

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: R 2 : 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: R 2 : 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., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: Childhood obesity is a major public health concern. Children with disabilities have a higher prevalence of obesity., Objective: We examined factors associated with obesity within a cross-sectional study of US adolescents with and without disabilities., Methods: Data were obtained from the 2011 Youth Risk Behavior Survey. Logistic regression models were fitted to assess effects of dietary habits, physical activity, and unhealthy weight control behaviors on obesity. Effect modification by disability status was examined., Results: Twenty percent (1986 of 9775 participants) reported a disability. Adolescents with disabilities were more likely to be obese (odds ratio [OR] = 1.7; 95% confidence interval [CI]: 1.3-2.1) and have at least 1 unhealthy weight control behavior (OR = 2.0; 95% CI: 1.6-2.5), and were less likely to be physically active (OR = 0.5; 95% CI: 0.4-0.6). Lack of physical activity, increased television watching/video game playing, and unhealthy weight loss behaviors were significantly associated with obesity regardless of disability status (p-for-interaction >.05)., Conclusions: Successful obesity interventions should target diet, physical activity, and weight control among adolescents with disabilities. Understanding barriers to healthier diet and physical activity for this population is critical to developing effective obesity prevention programs and reducing the prevalence of unhealthy weight control behaviors., (© 2016, American School Health Association.)

In this paper, we present a new modular lab on a chip design for multimodal neurotransmitter (NT) sensing and niosome generation based on a plug-and-play concept. This architecture is a first step toward an automated platform for an automated modulation of neurotransmitter concentration to understand and/or treat neurodegenerative diseases. A modular approach has been adopted in order to handle measurement or drug delivery or both measurement and drug delivery simultaneously. The system is composed of three fully independent modules: three-channel peristaltic micropumping system, a three-channel potentiostat and a multi-unit microfluidic system composed of pseudo-Y and cross-shape channels containing a miniature electrode array. The system was wirelessly controlled by a computer interface. The system is compact, with all the microfluidic and sensing components packaged in a 5 cm × 4 cm × 4 cm box. Applied to serotonin, a linear calibration curve down to 0.125 mM, with a limit of detection of 31 μ M was collected at unfunctionalized electrodes. Added sensitivity and selectivity was achieved by incorporating functionalized electrodes for dopamine sensing. Electrode functionalization was achieved with gold nanoparticles and using DNA and o-phenylene diamine polymer. The as-configured platform is demonstrated as a central component toward an "intelligent" drug delivery system based on a feedback loop to monitor drug delivery.

Context: Interval sports programs are a critical rehabilitation element when preparing the injured athlete for a return to preinjury activities. There is currently no published interval hitting program to guide a return to unrestricted play for the volleyball athlete. Therefore, data-based, position-specific overhead hitting programs that control for intensity, time, and number of ball strikes were developed for female college volleyball players., Evidence Acquisition: Records from a single Division I varsity women's volleyball team were examined for all matches during 7 consecutive years of team play. Data were collected for number of hitting and service attempts per game for each position and the number of games per match., Results: Per game, middle hitters averaged 4.51 attacks and 2.77 service attempts; right-side hitters, 3.58 attacks and 1.26 service attempts; outside hitters, 6.37 attacks and 3.44 service attempts; and setters and defensive specialists, 0.17 attacks and 1.78 service attempts., Conclusion: The interval hitting program can provide rehabilitation specialists with a data-based approach that may facilitate a return to play and minimize the risk of reinjury for volleyball athletes.

Context: Baseball throwing injuries are common. Emphasis on injury prevention and rehabilitation is made in an attempt to keep athletes on the field of competition. Interval throwing programs are an integral part of training, conditioning, and returning an injured baseball player to the game., Evidence Acquisition: Development of data-driven programs was based on the number, type, distance, and intensity of throws during games, across the spectrum of ages and positions for baseball athletes at all levels of play. Statistical analysis by age, position, and level of play determined the need for separate throwing programs. Means, the high range, game rules, and practical considerations were used to develop each data-based interval throwing program., Results: Data-based age and level-of-play interval throwing programs for pitchers, catchers, infielders, and outfielders have been developed, tested, and implemented for more than 10 years. Progression is based on type and location of injury, symptoms in response to throwing, and preinjury performance profile. Although the throwing programs are highly structured, there is ample opportunity to modify them to meet the needs of individual athletes., Conclusion: Data-based interval throwing programs for baseball athletes are an integral training and conditioning element for both injured and uninjured athletes who are preparing for sports participation. Medical team members should equip themselves with an understanding of how to use the programs for safe training, conditioning, and return to play.

Background: Identification of highly active individuals early after acute anterior cruciate ligament deficiency who are good candidates for nonoperative management is a clinical challenge. The University of Delaware has developed and validated a treatment algorithm and screening examination to distinguish between nonoperative and surgical candidates., Study Design: Review., Evidence Acquisition: A description of the decision-making rules and rehabilitation protocol for highly active individuals with anterior cruciate ligament deficiency is provided. Results from clinical trials, outcome studies, and biomechanical investigations conducted using the treatment algorithm and screening examination are also reviewed., Results: Patients identified as nonoperative rehabilitation candidates using these clinical guidelines have a far greater success rate than what has been reported when patients self-select nonoperative management. Furthermore, nonoperative outcomes are improved when patients participate in a perturbation-enhanced rehabilitation protocol. Divergent lower extremity movement patterns are consistent with the different functional abilities of the dichotomous patient groups identified with the screening examination., Conclusion: Given the differential patient response to anterior cruciate ligament injury, implementation of the decision-making guidelines discussed in this review offers clinicians the opportunity to provide individualized patient care rather than continuing with a blanket surgical treatment strategy.

Nonoperative management of anterior cruciate ligament (ACL) rupture has not been a successful option for those who participate in high-level physical activity. However, there are instances when patients may want to attempt to return to physically demanding activities with nonoperative rehabilitation for an ACL injury. The purpose of this commentary is to describe guidelines for nonoperative management of physically active individuals with ACL injuries who wish to return to preinjury levels of physical activity. The guidelines are based on the results of 2 clinical studies that improved the overall success of nonoperative management of physically active individuals with ACL ruptures. A decision-making process for selecting appropriate candidates for nonoperative management (rehabilitation candidates) is described. Individuals are classified as rehabilitation candidates if they have no concomitant ligament or mensical damage associated with the ACL injury, have a unilateral ACL injury, and meet all 4 of the following criteria: (1) timed hop test score of 80% or more of the uninjured limb, (2) Knee Outcome Survey Activities of Daily Living Scale score of 80% or more, (3) global rating of knee function of 60% or more, and (4) no more than 1 episode of giving way since the incident injury to the time of testing. Individuals meeting the criteria of a rehabilitation candidate undergo an intensive rehabilitation program before returning to high-level activity. The rehabilitation program consisting of lower extremity muscle strength training, cardiovascular endurance training, agility and sport-specific skill training, and a training program using balance perturbations is described.

Background and Purpose: Treatment techniques involving perturbations of support surfaces may induce compensatory muscle activity that could improve knee stability and increase the likelihood of returning patients to high-level physical activity. The purpose of this study was to determine the efficacy of augmenting standard nonoperative anterior cruciate ligament (ACL) rehabilitation programs with a perturbation training program., Subjects: Twenty-six patients with acute ACL injury or ruptures of ACL grafts participated in the study. Subjects had to have a unilateral ACL injury, be free of concomitant multiple ligament or meniscal damage requiring surgical repair, and pass a screening examination designed to identify patients who had the potential to return to high-level physical activity with nonoperative treatments. Subjects also had to be regular participants in level I activities (eg, soccer, football, basketball) or level II activities (eg, racquet sports, skiing, construction work)., Methods: Subjects were randomly assigned to either a group that received a standard rehabilitation program (standard group) or a group that received the standard program augmented with a perturbation training program (perturbation group). Treatment outcome was determined from scores on the Knee Outcome Survey's Activities of Daily Living Scale (ADLS) and Sports Activity Scale, a global rating of knee function, scores on a series of single-limb hop tests, measurements of maximum isometric quadriceps femoris muscle force output, and the group frequency of unsuccessful rehabilitation. Unsuccessful rehabilitation was defined as the occurrence of an episode of giving way of the knee or failure to maintain the functional status of a rehabilitation candidate on retesting., Results: More subjects had unsuccessful rehabilitation in the standard group compared with the perturbation group. There was a within-group x time interaction for the ADLS, global rating of knee function, and crossover hop test scores. These scores decreased from posttraining to the 6-month follow-up for the standard group., Conclusion and Discussion: Although both the standard program and the perturbation training program may allow subjects to return to high-level physical activity, the perturbation training program appears to reduce the risk of continued episodes of giving way of the knee during athletic participation and allows subjects to maintain their functional status for longer periods.

Single-leg hops are used clinically to assess knee function in patients following anterior cruciate ligament (ACL) rupture and reconstruction. Researchers study ACL-deficient individuals in order to identify movement strategies in the absence of a major knee stabilizer, thereby providing information to clinicians regarding treatment options. Single-leg hops represent an activity which places higher demands on the knee than walking or jogging. Hops are thought by some to represent demands that are more comparable to those found during high level sports. Therefore hopping might provide more information about knee stability during dynamic activities than less strenuous activities. This paper reflects one component of a larger study involving comparisons of joint motions and muscle activity patterns in uninjured individuals (n=10) and two groups of athletes who had complete ACL ruptures; one group had substantial knee instability (noncopers, n=10), and the other had no signs of knee instability (copers, n=11). In this paper we report the findings from the single-leg hop activity. The results indicate that coper subjects move in a manner nearly identical to uninjured persons. Kinetic data suggest that copers stabilize their knees with greater contributions from the ankle extensor muscles. Muscle activity data demonstrate that there is no reduction in quadriceps femoris activity in the coper subjects. In the group of ten subjects with knee instability (noncopers) who participated in the overall study involving walking, jogging, hopping, and a step activity only four were willing to hop. Work in our laboratory has established that when high level athletes rupture their ACL, the majority of them cannot return to high level sports. The small number of noncopers in this study who were willing to hop supports our previous findings. Those noncopers who did hop displayed reduced knee range of motion and external knee flexion moments, a movement strategy remarkably similar to that found during other activities. Neither the copers nor the noncopers showed evidence that quadriceps activation was diminished.

Purpose: The purpose of this study was to determine the relationship among laxity, quadriceps strength, instability, and function in subjects with complete rupture of the anterior cruciate ligament (ACL) who compensate well for the injury (copers) and those who require surgical stabilization (noncopers)., Methods: Forty-five patients with unilateral ACL rupture (confirmed via arthroscopy or magnetic resonance imaging (MRI) and arthrometer measurements) participated in this study. Subjects were divided into two groups: copers (N = 12), and subacute noncopers (N = 18) and chronic noncopers (N = 15). All copers had returned to all preinjury activity (including index sport) without limitation. Maximum manual anterior tibiofemoral laxity measurements, quadriceps femoris muscle strength measurements, and a series of hop tests were performed. Lysholm Scale, Knee Outcome Survey (KOS), global rating of knee function, and the International Knee Documentation Committee (IKDC) form were completed., Results: There was no significant difference in laxity between copers (X = 5.5+/-2.7 mm) and noncopers (chronic, X = 5.1+/-2.8 mm and subacute, X = 4.2+/-2.2 mm) or in IKDC scores among the groups. The copers, however, scored significantly better than the chronic and subacute ACL-deficient subsets on all other measures. Measurements of laxity were not correlated to any functional outcome measure or to episodes of instability., Conclusions: Copers were not different in any meaningful way from the noncopers before injury, had equal or greater side-to-side laxity differences, and functioned normally. A battery of tests was identified that accurately discriminated noncopers from copers even early after injury. Thus, measurements of laxity alone are insufficient for determining functional status after ACL injury.

The purpose of this study was to describe kinematic and kinetic differences between a group of ACL deficient subjects who were grouped according to functional ability. Sixteen patients with complete ACL rupture were studied; eight subjects had instability with activities of daily living (non-copers) and eight subjects had returned to all pre-injury activity without limitation (copers). Three-dimensional joint kinematics and kinetics were collected from the knee and ankle during walking, jogging and going up and over a step. Results showed that both groups mitigated the force with which they contacted the floor but non-copers consistently demonstrated less knee flexion in the involved limb. The copers used joint kinematics similar to those of their uninvolved knees and similar to knee motions reported in uninjured subjects. The reduced knee motion in the involved knee of the non-copers did not correlate directly with quadriceps femoris muscle weakness. The data suggest that the non-copers utilize a stabilization strategy which stiffens the knee joint which not only is unsuccessful but may lead to excessive joint contact forces which have the potential to damage articular structures. The copers use a strategy which permits normal knee kinematics and bodes well for joint integrity.

The ability of the health care professional to make correct decisions about the progression of weight-training is critical to the rehabilitation process. The purpose of this article is to describe our approach to modification of weight-lifting techniques using the injured shoulder as a model. Additionally, the impact of various upper extremity weight-training techniques on healthy athletes is discussed. The effects of grip, hand spacing, bar trajectory, and start and finishing positions on microtraumatic injury and return to weight-training activities after injury are considered. Several weight-training functional progressions for common multijoint exercises (such as bench press, shoulder press, power clean) are presented. Adaptations for periodization are also presented for implementation in the rehabilitation sequence. The weight-training modifications described in this paper will assist the health professional to safely return athletes to the weight room after shoulder injury.

We developed a distance-based interval throwing program for Little League-aged athletes (9 to 12 years) to be used in training and rehabilitation. The timing and repetition parameters were developed from data collected during 400 innings of organized baseball during a single season, and short toss distance from Little League rules for field dimensions. There were 1022 boys from organized baseball teams in the four studies. Maximal distance and speed measurements were recorded for 853 boys. We developed a mathematical model from these data to predict maximal throwing distance from maximal throwing speed. This model was then tested on a second sample of 114 players. We compared the predicted distance with the actual maximal throwing distance; the correlation coefficient was 0.92. Forty players aged 9 to 12 participated in a study to assess degradation of speed and distance. The average variability of the speed was small (< 5 mph), but the variability in distance was large (22.4 feet). Fifteen boys then threw the entire throwing program as designed. These results show that healthy young athletes can be expected to be able to throw the predicted value of this practical progressive interval throwing program for Little League-aged athletes. The appropriate program can be assigned from age and known preinjury pitch speed.

A one-year study was undertaken investigating adolescent sports injury experiences at a major sports clinic in the state of Delaware. A total of 619 athletes sustained 870 injuries, for an overall injury rate of 1.4 injuries per athlete. The largest number of injuries was recorded in football (40.2 percent), followed by boys' soccer, wrestling, baseball and girls' basketball. Severity of injury was measured by the number of days lost per injury. Cheerleading had the highest average days lost per injury (28.8), followed by girls' basketball, wrestling, boys' cross-country and girls' tennis. Inflammation, fractures and dislocations comprised 50.6 percent of all the injuries, while 50.5 percent of the injuries were located in the knee, thigh, and shoulder. Twenty-seven of the 870 injuries required surgery.

It is the closed gross deformity of the knee with vascular compromise that most commonly leads to amputation. This algorithm is offered as an approach to this problem with great medical and legal ramifications. Compartment syndrome about the elbow and foot can be avoided if the signs and symptoms are recognized and the fascial compartments released.