Identifying achilles tendon structure differences by ultrasound tissue characterization in asymptomatic individuals.

Ultrasound Tissue Characterization (UTC) is a modality that can be utilized to characterize tendon tissue structure using ultrasonographic imaging paired with a computer algorithm to distinguish echo-types. Several studies have demonstrated UTCs ability to distinguish Achilles tendon morphology changes, but no study has established normative data of the Achilles tendon in the general population. The aim of this study was to determine UTC echo-type distribution in the Achilles tendon in an asymptomatic population. UTC scans were completed and analyzed on 508 participants without Achilles tendinopathy. Dedicated UTC-algorithms were used to distinguish and calculate echo-type percentages and the fiber type distribution was compared. The overall sample echo-type percentages demonstrated greater levels of Type I and II echo-types, 65.73% and 32.00%, respectively, and lower levels of Type III and IV echo-types, 1.74% and 0.57%, respectively. In addition, females had lower levels of Echo-type I compared to men and greater levels of echo-type II (p < 0.001). We also found that African-Americans had significantly greater amounts of echo-type I and lesser amounts of echo-type II when compared to Caucasians (p < 0.05). The results of this study create a normative data set for future UTC studies to utilize as a baseline for the evaluation of Achilles tendons. In addition, it demonstrated tendon type differences between sexes and races that need to be accounted for in future studies.

Identifiable Factors Associated With Acceptance Into Sports Medicine Fellowship Programs: A Brief Report.

OBJECTIVE: To identify factors associated with entry into primary care sports medicine (PCSM) fellowship programs. DESIGN: Primary care sports medicine fellowship directors (FDs) and fellowship faculty were surveyed regarding preferences for accepting applicants into their programs. SETTING: Survey study. PARTICIPANTS: Primary care sports medicine FDs and fellowship faculty. ASSESSMENT OF RISK FACTORS: Questions were designed to delineate factors [clinical experience, letters of recommendation (LOR), scholarship, service commitment, interview performance, etc] perceived to be associated with entry into PCSM fellowship (1-10 scale; 10 = highest value). Weighted mean ± SD were calculated for each question. MAIN OUTCOME MEASURES: Determination of most valued factors for entry into PCSM fellowship. RESULTS: Responses were provided by 242/2332 (10.4%) of the American Medical Society for Sports Medicine members, including 77 of 175 (44%) FDs. The top 3 factors for entry into PCSM fellowships for all respondents were as follows: interview performance (9.17 ± 1.13), LOR from SM fellowship faculty (8.20 ± 1.67), and high school game/event coverage (7.83 ± 1.70). Musculoskeletal ultrasound experience (4.50 ± 2.23) and residency training in pediatrics (4.58 ± 2.54), internal medicine (4.48 ± 2.44), emergency medicine (4.44 ± 2.59), and physical medicine and rehabilitation (4.40 ± 2.83) received the lowest scores. CONCLUSIONS: Applicants seeking entry into SM fellowships should prioritize performance during interviews, LOR from SM fellowship faculty, and team game/event coverage experiences.

The use of an IL1-receptor antagonist to reverse the changes associated with established tendinopathy in a rat model.

Interleukin-1 (IL1) is a cytokine that plays a role in inflammation and is a potential contributor to the inflammation present in tendinopathy. Its inhibition may be of use in the treatment of tendinopathy and has been a target for treatment. To evaluate how an IL1-receptor antagonist (IL1-RA) reverses pathologic changes associated with established patellar tendinopathy, we randomized 48 Sprague-Dawley retired breeder rats into three groups having weekly bilateral patellar tendon injections for 6 weeks. The control group received 0.1 mL saline for 6 weeks. The intervention groups were treated with 0.1 mL 2% carrageenan for 4 weeks. Beginning at week three, the IL1-RA group received 0.94 mg of the IL1-RA (2.5 mg/kg) added to the 0.1 mL 2% carrageenan and 0.94 mg of the IL1-RA alone for the final 2 weeks, while the CAR received 0.1 mL saline for the final 2 weeks. Animals were euthanized 6 weeks after initial injection. The CAR group demonstrated significantly (P < 0.05) shorter tendon lengths (7.81 ± 0.44 mm) than the control (8.25 ± 0.58 mm) and IL1-RA (8.34 ± 0.52 mm) group (P < 0.05). Macroscopically, plaque-like formations were reduced and margins of the tendon were more evident in the IL1-RA group compared to the CAR group. CAR group demonstrated significantly greater histopathologic changes (inflammatory cell density, disorganization of collagen, nuclear rounding, and angiogenesis) than the control and IL1-RA group. No significant difference in mechanical properties of the tendon was noted. These findings demonstrate IL1-RA can reduce pathologic changes in the patellar tendon in an established tendonitis model although did not demonstrate a difference in mechanical properties.

Novice interpretation of screening electrocardiograms and impact of online training.

INTRODUCTION: It is not known whether there is a specific training method that improves the accuracy of physician interpretations of pre-participation electrocardiograms (ECGs). METHODS: Participants took an online test and interpreted a series of normal, normal variant and abnormal ECGs. They then reviewed the BMJ's ECG interpretation online learning module and completed a post-test and a follow-up examination three months later. RESULTS: 28 fellows enrolled. The average correct for the pre-test was 63.57%, which increased to 81.19% for the post-test (p≤0.0001). When evaluating for retention, the average fell to 73.33% (p=0.0116) but was still significantly improved from baseline (p=0.0253). CONCLUSIONS: This study demonstrated that the accuracy of fellows' interpretation of ECGs significantly improved after completion of BMJ modules. Results of this study will likely impact the training of future sports medicine fellows and should encourage fellowship directors to incorporate the BMJ's ECG interpretation module as part of their curriculum.

Sports medicine ultrasound (US) beyond the musculoskeletal system: use in the abdomen, solid organs, lung, heart and eye.

The use of point-of-care ultrasound (US) by non-radiologists is not new and the expansion into sports medicine practice is relatively young. US has been used extensively to evaluate the musculoskeletal system including the diagnosis of muscle, tendon and bone injuries. However, as sports medicine practitioners we are responsible for the care of the entire athlete. There are many other non-musculoskeletal applications of US in the evaluation and treatment of the athlete. This paper highlights the use of US in the athlete to diagnose pulmonary, cardiac, solid organ, intra-abdominal and eye injuries.

American Medical Society for Sports Medicine (AMSSM) position statement: interventional musculoskeletal ultrasound in sports medicine.

BACKGROUND: The use of diagnostic and interventional ultrasound has significantly increased over the past decade. A majority of the increased utilisation is by non-radiologists. In sports medicine, ultrasound is often used to guide interventions such as aspirations, diagnostic or therapeutic injections, tenotomies, releases and hydrodissections. OBJECTIVE: Critically review the literature related to the accuracy, efficacy and cost-effectiveness of ultrasound-guided injections (USGIs) in major, intermediate and small joints; and soft tissues. DESIGN: Systematic review of the literature. RESULTS: USGIs are more accurate than landmark-guided injections (LMGIs; strength of recommendation taxonomy (SORT) Evidence Rating=A). USGIs are more efficacious than LMGIs (SORT Evidence Rating=B). USGIs are more cost-effective than LMGIs (SORT Evidence Rating=B). Ultrasound guidance is required to perform many new procedures (SORT Evidence Rating=C). CONCLUSIONS: The findings of this position statement indicate there is strong evidence that USGIs are more accurate than LMGI, moderate evidence that they are more efficacious and preliminary evidence that they are more cost-effective. Furthermore, ultrasound-guided (USG) is required to perform many new, advanced procedures and will likely enable the development of innovative USG surgical techniques in the future.

American Medical Society for Sports Medicine recommended sports ultrasound curriculum for sports medicine fellowships.

The American Medical Society for Sports Medicine (AMSSM) developed a musculoskeletal ultrasound curriculum for sports medicine fellowships in 2010. As the use of diagnostic and interventional ultrasound in sports medicine has evolved, it became clear that the curriculum needed to be updated. Furthermore, the name 'musculoskeletal ultrasound' was changed to 'sports ultrasound' (SPORTS US) to reflect the broad range of diagnostic and interventional applications of ultrasound in sports medicine. This document was created to outline the core competencies of SPORTS US and to provide sports medicine fellowship directors and others interested in SPORTS US education with a guide to create a SPORTS US curriculum. By completing this SPORTS US curriculum, sports medicine fellows and physicians can attain proficiency in the core competencies of SPORTS US required for the practice of sports medicine.

American Medical Society for Sports Medicine position statement: interventional musculoskeletal ultrasound in sports medicine.

The use of diagnostic and interventional ultrasound has significantly increased over the past decade. A majority of the increased utilization is by nonradiologists. In sports medicine, ultrasound is often used to guide interventions such as aspirations, diagnostic or therapeutic injections, tenotomies, releases, and hydrodissections. This American Medical Society for Sports Medicine (AMSSM) position statement critically reviews the literature and evaluates the accuracy, efficacy, and cost-effectiveness of ultrasound-guided injections in major, intermediate, and small joints, and soft tissues, all of which are commonly performed in sports medicine. New ultrasound-guided procedures and future trends are also briefly discussed. Based on the evidence, the official AMSSM position relevant to each subject is made.

American Medical Society for Sports Medicine recommended sports ultrasound curriculum for sports medicine fellowships.

The following sports ultrasound (SPORTS US) curriculum is a revision of the curriculum developed by the American Medical Society for Sports Medicine (AMSSM) in 2010. Several changes have been made to the curriculum with the primary aim of providing a pathway by which a sports medicine fellow can obtain sufficient SPORTS US training to become proficient in the core competencies of SPORTS US. The core competencies of SPORTS US are outlined in the learning objectives section of this document. The term "SPORTS US" was purposefully chosen rather than "musculoskeletal ultrasound" (MSK US) because it was recognized by the panel that the evolving field of SPORTS US encompasses non-MSK applications of ultrasound such as the FAST examination (focused assessment with sonography for trauma). Although the SPORTS US core competencies in this curriculum are all MSK in nature, they represent the minimum SPORTS US knowledge a sports medicine fellow should acquire during fellowship. However, additional training in more advanced MSK and non-MSK applications of ultrasound can be provided at the fellowship director's discretion. Completion of this SPORTS US curriculum fulfills the American Institute of Ultrasound in Medicine's (AIUM) requirements to perform an MSK US examination and the prerequisites for the American Registry for Diagnostic Medical Sonography's (ARDMS) MSK sonography certification examination.

Whole body and local muscle vibration reduce artificially induced quadriceps arthrogenic inhibition.

OBJECTIVE: To evaluate the effects of whole body vibration (WBV) and local muscle vibration (LMV) on quadriceps function after experimental knee effusion (ie, simulated pathology). DESIGN: Randomized controlled trial. SETTING: Research laboratory. PARTICIPANTS: Healthy volunteers (N=43) were randomized to WBV (n=14), LMV (n=16), or control (n=13) groups. INTERVENTIONS: Saline was injected into the knee to induce quadriceps arthrogenic muscle inhibition (AMI). All groups then performed isometric squats while being exposed to WBV, LMV, or no vibration (control). MAIN OUTCOME MEASURES: Quadriceps function was assessed at baseline, immediately after effusion, and immediately and 5 minutes after each intervention (WBV, LMV, control) via voluntary peak torque (VPT) and the central activation ratio (CAR) during maximal isometric knee extension on a multifunction dynamometer. RESULTS: The CAR improved in the WBV (11.4%, P=.021) and LMV (7.3%, P<.001) groups immediately postintervention, but they did not improve in the control group. Similarly, VPT increased by 16.5% (P=.021) in the WBV group and 23% (P=.078) in the LMV group immediately postintervention, but it did not increase in the control group. The magnitudes of improvements in the CAR and VPT did not differ between the WBV and LMV groups. CONCLUSIONS: Quadriceps AMI is a common complication following knee pathology that produces quadriceps dysfunction and increases the risk of posttraumatic osteoarthritis. Quadriceps strengthening after knee pathology is often ineffective because of AMI. WBV and LMV improve quadriceps function equivocally after simulated knee pathology, effectively minimizing quadriceps AMI. Therefore, these stimuli may be used to enhance quadriceps strengthening, therefore improving the efficacy of rehabilitation and reducing the risk of osteoarthritis.

Sustained Limb-Level Loading: A Ground Reaction Force Phenotype Common to Individuals at High Risk for and Those With Knee Osteoarthritis.

OBJECTIVE: The objective of this study was to compare the vertical (vGRF), anterior-posterior (apGRF), and medial-lateral (mlGRF) ground reaction force (GRF) profiles throughout the stance phase of gait (1) between individuals 6 to 12 months post-anterior cruciate ligament reconstruction (ACLR) and uninjured matched controls and (2) between ACLR and individuals with differing radiographic severities of knee osteoarthritis (KOA), defined as Kellgren and Lawrence (KL) grades KL2, KL3, and KL4. METHODS: A total of 196 participants were included in this retrospective cross-sectional analysis. Gait biomechanics were collected from individuals 6 to 12 months post-ACLR (n = 36), uninjured controls matched to the ACLR group (n = 36), and individuals with KL2 (n = 31), KL3 (n = 67), and KL4 osteoarthritis (OA) (n = 26). Between-group differences in vGRF, apGRF, and mlGRF were assessed in reference to the ACLR group throughout each percentage of stance phase using a functional linear model. RESULTS: The ACLR group demonstrated lower vGRF and apGRF in early and late stance compared to the uninjured controls, with large effects (Cohen's d range: 1.35-1.66). Conversely, the ACLR group exhibited greater vGRF (87%-90%; 4.88% body weight [BW]; d = 0.75) and apGRF (84%-94%; 2.41% BW; d = 0.79) than the KL2 group in a small portion of late stance. No differences in mlGRF profiles were observed between the ACLR and either the uninjured controls or the KL2 group. The magnitude of difference in GRF profiles between the ACLR and OA groups increased with OA disease severity. CONCLUSION: Individuals 6 to 12 months post-ACLR exhibit strikingly similar GRF profiles as individuals with KL2 KOA, suggesting both patient groups may benefit from targeted interventions to address aberrant GRF profiles.

Fibrin glue as a non-invasive outpatient treatment for post-arthroscopic knee seromas.

Post-surgical seromas and cysts have been reported across many surgical subspecialties including orthopaedics. Treatments include both invasive surgical approaches and more recently reported non-invasive techniques. Non-invasive approaches currently include compressive wrapping, vasopneumatic cryotherapy, and motion exercises. Persistent lesions have been treated with talc or doxycycline sclerodesis. This case presents a patient with a post-arthroscopic seroma that was treated with fibrin glue in an outpatient setting. Fibrin glue has not been reported in the post-arthroscopy outpatient setting to address cystic lesions. This case suggests a viable non-invasive treatment option for these lesions. Level of evidence V.

Changes in biomechanics, strength, physical function, and daily steps after extended-release corticosteroid injections in knee osteoarthritis: a responder analysis.

INTRODUCTION/OBJECTIVE: To determine changes in gait biomechanics, quadricep strength, physical function, and daily steps after an extended-release corticosteroid knee injection at 4 and 8 weeks post-injection in individuals with knee osteoarthritis as well as between responders and non-responders based on changes in self-reported knee function. METHOD: The single-arm, clinical trial included three study visits (baseline, 4 weeks, and 8 weeks post-injection), where participants received an extended-release corticosteroid injection following the baseline visit. Time-normalized vertical ground reaction force (vGRF), knee flexion angle (KFA), knee abduction moment (KAM), and knee extension moment (KEM) waveforms throughout stance were collected during gait biomechanical assessments. Participants also completed quadricep strength, physical function (chair-stand, stair-climb, 20-m fast-paced walk) testing, and free-living daily step assessment for 7 days following each visit. RESULTS: All participants demonstrated increased KFA excursion (i.e., greater knee extension angle at heel strike and KFA at toe-off), increased KEM during early stance, improved physical function (all p < 0.001), and increased quadricep strength at 4 and 8 weeks. KAM increased throughout most of stance at 4 and 8 weeks post-injection (p < 0.001) but appears to be driven by gait changes in non-responders. Non-responders demonstrated lesser vGRF during late stance and lesser KEM and KFA throughout stance compared to responders at baseline. CONCLUSIONS: Extended-release corticosteroid injections demonstrated short-term improvements in gait biomechanics, quadricep strength, and physical function for up to 4 weeks. However, non-responders demonstrated gait biomechanics associated with osteoarthritis progression prior to the corticosteroid injection, suggesting that non-responders demonstrate more deleterious gait biomechanics prior to corticosteroid injection. Key Points • Individuals with knee osteoarthritis who were treated with extended-release corticosteroid injections demonstrated improvements in gait biomechanics and physical function for 8 weeks. • Individuals with knee osteoarthritis, who walked with aberrant walking biomechanics before treatment, failed to respond to extended-release corticosteroid treatment. • Future research should determine the mechanisms contributing to the short-term changes in gait biomechanics and physical function such as reduced inflammation.

The role of leukotriene inhibition using a 5-lipoxygenase (5-LO) inhibitor in a joint contracture model.

PURPOSE: Arthrofibrosis is a common inflammatory complication of joint trauma and surgery. 5lipoxygenase (5-LO) is a key enzyme involved in inflammation. Inhibition of 5-LO has been shown to reduce inflammation in heart and lung models but has not been examined in a joint contracture model. METHODS: Twenty-six rats underwent joint contracture. Six rats served as non-surgical controls. A 5-LO inhibitor, caffeic acid (CA), suspended in 10% ethanol was orally administered to 14 rats and ethanol without CA to the remaining 12 rats daily for 21 days. Leukotriene B4 (LTB4) levels were measured, both systemically and locally. 5-LO levels in the posterior capsule were quantified by measuring the ratio of the length of the posterior capsule demonstrating 5-LO immunostaining to the total length of the capsule. RESULTS: Joint contracture was successfully achieved in all rats who underwent manipulation. Levels of 5- LO measured in the posterior capsule were significantly increased in the animals who underwent surgery (56%/44-64) compared to the non-surgical control animals (7%/4-9). LTB4 levels were found to be significantly lower in the non-surgical control animals (107.79 ± 34.08 pg/ml) compared to all surgical animals (157.6 ± 55.3 pg/ml). CONCLUSION: Surgical intervention resulted in increased 5-LO activity of the synovial surface of the posterior capsule and increased LTB4 levels in the patellar tendon-fat pad. Oral administration of the 5LO inhibitor, CA, was ineffective at reducing systemic and local LTB4 levels and preventing knee joint contracture. Inhibiting 5-LO activity may still be effective in preventing arthrofibrosis and warrants further investigation.

Preventing Osteoarthritis After an Anterior Cruciate Ligament Injury: An Osteoarthritis Action Alliance Consensus Statement.

After an anterior cruciate ligament (ACL) injury, people need secondary prevention strategies to identify osteoarthritis at its earliest stages so that interventions can be implemented to halt or slow the progression toward its long-term burden. The Osteoarthritis Action Alliance formed an interdisciplinary Secondary Prevention Task Group to develop a consensus on recommendations to provide clinicians with secondary prevention strategies that are intended to reduce the risk of osteoarthritis after a person has an ACL injury. The group achieved consensus on 15 out of 16 recommendations that address patient education, exercise and rehabilitation, psychological skills training, graded-exposure therapy, cognitive-behavioral counseling (lacked consensus), outcomes to monitor, secondary injury prevention, system-level social support, leveraging technology, and coordinated care models. We hope this statement raises awareness among clinicians and researchers on the importance of taking steps to mitigate the risk of osteoarthritis after an ACL injury.

Evidence Review for Preventing Osteoarthritis After an Anterior Cruciate Ligament Injury: An Osteoarthritis Action Alliance Consensus Statement.

CONTEXT: The Osteoarthritis Action Alliance formed a secondary prevention task group to develop a consensus on secondary prevention recommendations to reduce the risk of osteoarthritis after a knee injury. OBJECTIVE: Our goal was to provide clinicians with secondary prevention recommendations that are intended to reduce the risk of osteoarthritis after a person has sustained an anterior cruciate ligament injury. Specifically, this manuscript describes our methods, literature reviews, and dissenting opinions to elaborate on the rationale for our recommendations and to identify critical gaps. DESIGN: Consensus process. SETTING: Virtual video conference calls and online voting. PATIENTS OR OTHER PARTICIPANTS: The Secondary Prevention Task Group consisted of 29 members from various clinical backgrounds. MAIN OUTCOME MEASURE(S): The group initially convened online in August 2020 to discuss the target population, goals, and key topics. After a second call, the task group divided into 9 subgroups to draft the recommendations and supportive text for crucial content areas. Twenty-one members completed 2 rounds of voting and revising the recommendations and supportive text between February and April 2021. A virtual meeting was held to review the wording of the recommendations and obtain final votes. We defined consensus as >80% of voting members supporting a proposed recommendation. RESULTS: The group achieved consensus on 15 of 16 recommendations. The recommendations address patient education, exercise and rehabilitation, psychological skills training, graded-exposure therapy, cognitive-behavioral counseling (lacked consensus), outcomes to monitor, secondary injury prevention, system-level social support, leveraging technology, and coordinated care models. CONCLUSIONS: This consensus statement reflects information synthesized from an interdisciplinary group of experts based on the best available evidence from the literature or personal experience. We hope this document raises awareness among clinicians and researchers to take steps to mitigate the risk of osteoarthritis after an anterior cruciate ligament injury.

Glenohumeral Hydrodistension for Postoperative Stiffness After Arthroscopic Primary Rotator Cuff Repair.

Background: Postoperative stiffness is a known complication after rotator cuff repair (RCR). Glenohumeral hydrodistension (GH) has been a treatment modality for shoulder pathology but has not been used to treat postoperative stiffness after RCR. Purpose/Hypothesis: The purpose of this study was to identify the risk factors for postoperative stiffness after RCR and review outcomes after treatment with GH. Our hypotheses were that stiffness would be associated with diabetes and hyperlipidemia and correlated with the tendons involved and that patients with stiffness who underwent GH would have significant improvement in range of motion (ROM). Study Design: Case series; Level of evidence, 4. Methods: Included were 388 shoulders of patients who underwent primary RCR by a single surgeon between 2015 and 2019. Shoulders with revision RCRs were excluded. Patient characteristics, medical comorbidities, and perioperative details were collected. A total of 40 shoulders with postoperative stiffness (10.3%) received GH injectate of a 21-mL mixture (15 mL of sterile water, 5 mL of 0.5% ropivacaine, and 1 mL of triamcinolone [10 mg/mL]). The primary outcome measure was ROM in forward flexion, internal rotation, external rotation, and abduction. Statistical tests were performed using analysis of variance. Results: Patients with diabetes had significantly decreased internal rotation at final follow-up after RCR as compared with patients without diabetes. GH to treat stiffness was performed most commonly between 1 and 4 months after RCR (60%), and patients who received GH saw statistically significant improvements in forward flexion, external rotation, and abduction after the procedure. Patients with hyperlipidemia had the most benefit after GH. Among those undergoing concomitant procedures, significantly more patients who had open subpectoral biceps tenodesis underwent GH. Patients who underwent subscapularis repair or concomitant subacromial decompression had significant improvement in ROM after GH. Only 1 patient who received GH underwent secondary surgery for resistant postoperative stiffness. Conclusion: Patients with diabetes had increased stiffness. Patients with a history of hyperlipidemia or concomitant open subpectoral biceps tenodesis were more likely to undergo GH for postoperative stiffness. Patients who underwent subscapularis repair demonstrated the most improvement in ROM after GH. After primary RCR, GH can increase ROM and is a useful adjunct for patients with stiffness to limit secondary surgery.

Brief Educational Video plus Telecare to Enhance Recovery for Older Emergency Department Patients with Acute Musculoskeletal Pain: an update to the study protocol for a randomized controlled trial.

BACKGROUND: This update describes changes to the Brief Educational Tool to Enhance Recovery (BETTER) trial in response to the COVID-19 pandemic. METHODS/DESIGN: The original protocol was published in Trials. Due to the COVID-19 pandemic, the BETTER trial converted to remote recruitment in April 2020. All recruitment, consent, enrollment, and randomization now occur by phone within 24 h of the acute care visit. Other changes to the original protocol include an expansion of inclusion criteria and addition of new recruitment sites. To increase recruitment numbers, eligibility criteria were expanded to include individuals with chronic pain, non-daily opioid use within 2 weeks of enrollment, presenting musculoskeletal pain (MSP) symptoms for more than 1 week, hospitalization in past 30 days, and not the first time seeking medical treatment for presenting MSP pain. In addition, recruitment sites were expanded to other emergency departments and an orthopedic urgent care clinic. CONCLUSIONS: Recruiting from an orthopedic urgent care clinic and transitioning to remote operations not only allowed for continued participant enrollment during the pandemic but also resulted in some favorable outcomes, including operational efficiencies, increased enrollment, and broader generalizability. TRIAL REGISTRATION: ClinicalTrials.gov NCT04118595 . Registered on October 8, 2019.

Differences in Biomechanical Loading Magnitude During a Landing Task in Male Athletes with and without Patellar Tendinopathy.

CONTEXT: Prior research has not established if overloading or underloading movement profiles are present in symptomatic and asymptomatic athletes with patellar tendon structural abnormality (PTA) compared to healthy athletes. OBJECTIVE: The purpose was to compare involved limb landing biomechanics between male athletes with and without patellar tendinopathy. DESIGN: Cross-sectional study Setting: Laboratory Patients or Other Participants: 43 males were grouped based on patellar tendon pain & ultrasound imaging of the proximal patellar tendon: symptomatic with PTA (SYM-PTA; n=13; 20±2yrs; 1.8±0.1m; 84±5kg), asymptomatic with PTA (ASYM-PTA; n=15; 21±2yrs; 1.8±0.1m; 82±13kg), and healthy control (CON; n=15; 20±2yrs; 1.8±0.1m; 79±12kg). MAIN OUTCOME MEASURES: 3D biomechanics were collected during double-limb jump-landing. Kinematic (knee flexion angle (KF)) and kinetic (vertical ground reaction force (VGRF); internal knee extension moment (KEM); patellar tendon force (FPT)) variables were analyzed as continuous waveforms during the stance phase for the involved limb. Mean values were calculated for each 1% of stance, normalized over 202 data points (0-100%), and plotted with 95% confidence intervals. Statistical significance was defined as a lack of 95% CI overlap for ≥ 6 consecutive data points. RESULTS: SYM-PTA had lesser KF than CON throughout the stance phase. ASYM-PTA had lesser KF than CON in the early and late stance phase. SYM-PTA group had lesser KEM and FPT than CON in early stance, as well as ASYM-PTA in mid-stance. CONCLUSIONS: Male athletes with SYM-PTA demonstrated a patellar tendon load-avoidance profile compared to ASYM-PTA and CON athletes. ASYM-PTA did not show evidence of overloading compared to CON. Our findings support the need for individualized treatments for athletes with tendinopathy to maximize load-capacity. TRIAL REGISTRY: ClinicalTrials.gov (#XXX).

Interleukin-1 receptor antagonist inhibits arthrofibrosis in a post-traumatic knee immobilization model.

BACKGROUND: Therapies for arthrofibrosis after knee surgery are needed to prevent loss of joint function. Interleukin-1 receptor antagonists (IL-1RA) have shown promise in treating established arthrofibrosis in pilot clinical studies. The objective of this study was to evaluate the ability of intra-articular injection of IL-1RA to prevent knee joint contracture in a post-traumatic knee immobilization model. METHODS: 20 male Sprague Dawley rats were block randomized into two groups: control and IL-1RA. Rats underwent intra-articular surgical trauma of the right knee with placement of an immobilization suture, securing the knees in 150° flexion. On post-operative days 1 and 8, each group received a 0.1 ml intra-articular injection of either saline (control) or anakinra (IL-1RA:single dosage; 2.63 mg/kg). Rats were euthanized fourteen days after surgery and the immobilization femorotibial angles were measured on the operative limbs with the suture and musculature intact. Subsequently, musculature was removed and femorotibial angles were measured in the operative and non-operative limbs with a defined extension moment applied with the posterior capsule intact or cut. A contracture angle was calculated as the angular difference between the operative and non-operative limb. RESULTS: The immobilization knee flexion angle did not differ (P = 0.761) between groups (control: 152 ± 9; IL-1RA: 150 ± 11). The joint contracture angles (smaller angle = improved outcome) were reduced by 12 degrees on average in the IL-1RA group compared to the control for both the capsule intact (P = 0.024) and cut (P = 0.019) states. CONCLUSIONS: Intra-articular IL-1RA injection was found to diminish knee extension deficits associated with arthrofibrosis in a post-traumatic joint immobilization model.