Normative ultrasound values for Achilles tendon thickness in the general population and patients with Achilles tendinopathy: A large international cross-sectional study.

The objective of the study was to obtain adjusted ultrasonographic reference values of the Achilles tendon thickness (maximum anterior-posterior distance) in adults without (previous) Achilles tendinopathy (AT) and to compare these reference values with AT patients. Six hundred participants were consecutively included, comprising 500 asymptomatic individuals and 100 patients with clinically diagnosed chronic AT. The maximum tendon thickness was assessed using Ultrasound Tissue Characterization. A multiple quantile regression model was developed, incorporating covariates (personal characteristics) that were found to have a significant impact on the maximum anterior-posterior distance of the Achilles tendon. A 95% reference interval (RI) was derived (50th, 2.5th-97.5th percentile). In asymptomatic participants median (95% RI) tendon thickness was 4.9 (3.8-6.9) mm for the midportion region and 3.7 (2.8-4.8) mm for the insertional region. Age, height, body mass index, and sex had a significant correlation with maximum tendon thickness. Median tendon thickness for the midportion region was calculated with the normative equation -2.1 + AGE × 0.021 + HEIGHT × 0.032+ BMI × 0.028 + SEX × 0.05. For the insertional region, the normative equation was -0.34 + AGE × 0.010+ HEIGHT × 0.018 + BMI × 0.022 + SEX × -0.05. In the equations, SEX is defined as 0 for males and 1 for females. Mean (95% CI) difference in tendon thickness compared to AT patients was 2.7 mm (2.3-3.2, p < 0.001) for the midportion and 1.4 mm (1.1-1.7, p < 0.001) for the insertional region. Compared to the asymptomatic population 73/100 (73%) AT patients exhibited increased tendon thickening, with values exceeding the 95% RI. This study presents novel reference values for the thickness of midportion and insertional region of the Achilles tendon, which were adjusted for personal characteristics. Our novel web-based openly accessible calculator for determining normative Achilles tendon thickness (www.achillestendontool.com) will be a useful resource in the diagnostic process. Trial registration number: This trial is registered in the Netherlands Trial Register (NL9010).

Measuring Ultrasonographic Thickness of the Achilles Tendon Insertion Is Less Reliable Than the Midportion in Healthy Tendons and Patients With Tendinopathy.

INTRODUCTION: Ultrasound is the preferred imaging method in the diagnostic process of Achilles tendinopathy (AT). Ultrasound tissue characterization (UTC) is a frequently used, standardized and valid method to assess tendon geometry in AT patients. It is unknown whether UTC is reliable for measuring Achilles tendon thickness. The aim of the study was to assess intra- and inter-rater reliability of Achilles tendon thickness measurements using UTC in both asymptomatic individuals and patients with AT, and to evaluate if the reliability of thickness measurements differs between the midportion and insertional area. METHODS: Exactly 50 patients with AT and 50 asymptomatic individuals were included. Using the conventional US and standardized UTC procedure maximum thickness was measured in the midportion and insertion region. To determine inter- and intra-rater reliabilities, the intraclass correlation coefficient (ICC) was used. RESULTS: The ICC values for inter- and intra-rater reliability were classified as "excellent," for the AT group (0.93 [95% CI: 0.88-0.96] and 0.95 [0.92-0.97]) and asymptomatic participants (0.91 [0.87-0.94] and 0.94 [0.92-0.96]). The reliability of measuring tendon thickness in the midportion region was "excellent," with both inter-rater (0.97 [0.95-0.98]) and intra-rater (0.98 [0.96-0.99]) ICC values indicating high levels of agreement. In the insertional region, ICC values for inter-rater (0.79 [0.69-0.87]) and intra-rater (0.89 [0.84-0.93]) reliability were "moderate to good." CONCLUSION: We showed excellent reliability for measuring the US thickness of the midportion and good reliability of measuring the insertional region in patients with AT. Significantly lower ICCs were observed for the reliability of thickness measurements in the insertional region when compared with the midportion.

Low socioeconomic status is associated with worse treatment outcomes in patients with Achilles tendinopathy.

OBJECTIVE: To assess whether there is a difference in symptom severity at baseline and 24 weeks follow-up between conservatively managed patients with Achilles tendinopathy (AT) with low socioeconomic status (SES) compared with those with high SES. METHODS: In this prospective cohort study, 200 patients with AT were included and treated according to current guidelines. We linked a neighbourhood SES indicator based on income, employment and education level and divided the patient population into quintiles, with Q1 being the highest SES and Q5 the lowest. Symptom severity at baseline and follow-up was assessed using the Victorian Institute of Sports Assessment-Achilles (VISA-A) score. Treatment adherence was not measured. We used a general linear model and the mean VISA-A scores at baseline and at 6, 12 and 24 weeks follow-up were compared between Q1 (n=45) and Q5 (n=39), while adjusting for age, sex, body mass index (BMI), Ankle Activity Score, symptom duration and baseline VISA-A score. RESULTS: Patients had a median age of 51 years and median BMI of 25.4, 40% were female. 74%, 70% and 58% of the participants completed the VISA-A at 6, 12 and 24 weeks, respectively. VISA-A scores at baseline were similar for Q1 and Q5 (43.9 and 41.8, p=0.591). At 24 weeks, there was a mean (95% CI) difference of 11.2 (1.0 to 21.3, p=0.032) points in favour of Q1 on the VISA-A score. CONCLUSION: AT patients with low SES may have worse outcomes when treated using the current guidelines. The difference in VISA-A score at 24 weeks is larger than the minimal clinically important difference and might be clinically relevant, but comes with uncertainty due to the large dispersion in the data. Clinicians need to consider the impact of social inequality when developing and implementing treatment plans.

TENDINopathy Severity assessment-Achilles (TENDINS-A): evaluation of reliability and validity in accordance with COSMIN recommendations.

OBJECTIVE: To evaluate the construct validity (structural validity and hypothesis testing), reliability (test-retest reliability, measurement error and internal consistency) and minimal important change (MIC) of the 13-item TENDINopathy Severity assessment-Achilles (TENDINS-A). METHODS: Participants with Achilles pain completed an online survey including: demographics, TENDINS-A, Foot and Ankle Outcome Score (FAOS) and Victorian Institute of Sport Assessment-Achilles (VISA-A). Exploratory factor analysis (EFA) assessed dimensionality. Confirmatory factor analysis (CFA) assessed structural validity (root mean square error of approximation (RMSEA); Comparative Fit Index (CFI); Tucker-Lewis Index (TLI); standardised root measure square (SRMS)). Correlations between TENDINS-A and the FAOS or VISA-A assessed hypothesis testing. Intraclass correlation (ICC) assessed test-retest reliability. Cronbach's alpha assessed internal consistency. SE of the measurement (SEM) assessed measurement error. A distribution-based approach assessed MIC. RESULTS: 79 participants (51% female) with a mean (SD) age=42.6 (13.0) years, height=175.0 (11.7) cm and body mass=82.0 (19.1) kg were included. EFA identified three meaningful factors, proposed as pain, symptoms and function. The best model identified using CFA for TENDINS-A had structural validity (RMSEA=0.101, CFI=0.959, TLI=0.947, SRMS=0.068), which included three factors (pain, symptoms and function), but excluded three items from the original TENDINS-A. TENDINS-A exhibited moderate positive correlation with FAOS (r=0.598, p<0.001) and a moderate negative correlation with VISA-A (r=-0.639, p<0.001). Reliability of the TENDINS-A was excellent (ICC=0.930; Cronbach's α=0.808; SEM=6.54 units), with an MIC of 12 units. CONCLUSIONS: Our evaluation of the revised 10-item TENDINS-A determined it has construct validity and excellent reliability, compared with the VISA-A and FAOS which lack content and construct validity. The TENDINS-A is recommended as the preferred patient-reported outcome measure to assess disability in people with Achilles tendinopathy.

Factors Associated With Running-Related Injuries in Recreational Runners With a History of Running Injuries.

OBJECTIVE: To identify the incidence and characteristics associated with a higher injury risk in recreational runners who suffered a running-related injury (RRI) in the previous 12 months. DESIGN: Prospective cohort study among recreational runners who registered for a Dutch running event (5-42.2 km) and suffered an RRI in the 12 months before inclusion. SETTING: Open population. PARTICIPANTS: Recreational runners with a previous reported injury. ASSESSMENT OF RISK FACTORS: At baseline, information on demographics, training characteristics, health complaints, and RRI history was collected. MAIN OUTCOME MEASURES: With 3 follow-up questionnaires (2 weeks before, 1 day after, and 1 month after the running event), the occurrence of new RRIs was registered. RESULTS: In total, 548 participants (55.1%) sustained a new RRI during follow-up. In total, 20.5% of the new RRIs was located at the same anatomical location as the previous RRI. Runners who registered for a marathon had a higher chance to sustain a new RRI [odd ratio (OR) 1.72; 95% confidence intervals (CIs), 1.17-2.53]. Also previous RRIs in the upper leg (OR 1.59; 95% CI, 1.15-2.19) and lower leg (OR 1.61; 95% CI, 1.18-2.21) were associated with an increased injury risk. CONCLUSIONS: Especially being a marathon runner and the anatomical location of previous RRIs seem to be associated with the injury risk in recreational runners with a previous RRI.

Risk Factors for Musculoskeletal Injury in CrossFit: A Systematic Review.

The objective of this systematic review was to identify potential risk factors for injury in CrossFit participants. Embase, Medline, Web of Science, Cochrane, CINAHL, Google Scholar, and SportDiscuss databases were all searched up to June 2021. Cohort studies that investigated risk factors for CrossFit injuries requiring medical attention or leading to time loss in sports were included. A best-evidence synthesis was performed combining all the outcomes from prospective cohort studies. From 9,452 publications identified, we included three prospective cohort studies from which two had a low risk of bias and one a high risk of bias. The studies examined 691 participants of whom 172 sustained an injury. There was limited evidence that switching between prescribed and scaled loads during training is associated with increased injury risk and that increased duration of participation is a protective factor for injury. This could mean that novice CrossFit athletes and those increasing their training load should have closer supervision by CrossFit coaches. These risk factors should be considered when developing preventive interventions.

Educational online prevention programme (the SPRINT study) has no effect on the number of running-related injuries in recreational runners: a randomised-controlled trial.

OBJECTIVES: The aim of this study was to examine the effectiveness of an enhanced online injury prevention programme on the number of running-related injuries (RRIs) in recreational runners. METHODS: We conducted a randomised-controlled trial in runners who registered for running events (distances: 10-42.195 km) in the Netherlands. Adult runners who provided informed consent were randomised into the intervention or control group. Participants in the intervention group received access to the online prevention programme, which included items to prevent RRIs. Participants in the control group followed their regular preparation for the running event. The primary outcome measure was the number of new RRIs from baseline to 1 month after the running event. To determine differences between injury proportions, univariate and multivariate logistic regression analyses were performed. RESULTS: This study included 4050 recreational runners (63.5% males; mean (SD) age: 42.3 (12.1) years) for analyses. During follow-up, 35.5% (95% CI: 33.5 to 37.6) of the participants in the intervention group sustained a new RRI compared with 35.4% (95% CI: 33.3 to 37.5) of the participants in the control group, with no between-group difference (OR: 1.03; 95% CI: 0.90 to 1.17). There was a positive association between the number of items followed in the injury prevention programme and the number of RRIs (OR: 1.05; 95% CI: 1.00 to 1.11). CONCLUSION: The enhanced online injury prevention programme had no effect on the number of RRIs in recreational runners, and being compliant with the programme paradoxically was associated with a slightly higher injury rate. Future studies should focus on individual targeted prevention with emphasis on the timing and application of preventive measures. TRIAL REGISTRATION NUMBER: NL7694.

Consequences and Prognosis of Running-Related Knee Injuries Among Recreational Runners.

OBJECTIVE: To investigate the consequences and prognostic factors of running-related knee injuries (RRKIs) among recreational runners. DESIGN: Prospective cohort study. SETTING: This study is part of a randomized-controlled trial (RCT) on running injury prevention among recreational runners. At baseline during registration for a running event (5-42 km), demographic and training variables were collected. Participants who reported a new RRKI during follow-up were sent a knee-specific questionnaire at 16 months (range 11.7-18.6) after baseline. PARTICIPANTS: One hundred thirty-eight runners who reported a new RRKI during the RCT on injury prevention responded to the knee-specific questionnaire. ASSESSMENT OF RISK FACTORS: To determine the association between potential prognostic factors and time to recovery of an RRKI, a Cox regression analysis was performed. MAIN OUTCOME MEASURES: Time to recovery and prognostic factors of RRKIs. RESULTS: At 16 months after registration, 71.0% of the participants reported full recovery, with a median time to recovery of 8.0 weeks. Most participants reported iliotibial band syndrome (23.2%) or osteoarthritis (OA)/degenerative meniscopathy (23.2%) as cause of their injury. Male sex was associated with a shorter time to recovery [hazard ratio (HR) 1.84; 95% confidence interval (CI), 1.14-2.97], while suffering knee OA was associated with a longer time to recovery (HR 0.17; 95% CI, 0.06-0.46). CONCLUSIONS: Nonrecovered participants adjusted running speed more often and had knee imaging more often than recovered participants. At follow-up, one-third of the participants were not recovered. This emphasizes the need for injury prevention programs for runners. More knowledge on the role of running in knee OA seems important, given the high number of participants with knee OA symptoms.

Do High-Volume Injections Affect the Ultrasonographic Neovascularization in Chronic Achilles Tendinopathy? A Randomized Placebo-Controlled Clinical Trial.

OBJECTIVE: High-volume injections (HVIs) are thought to target neovascularization in chronic midportion Achilles tendinopathy (AT), yet the mechanism has not been clarified. Therefore, we aim to evaluate whether a HVI decreases ultrasonographic Doppler flow in patients with chronic midportion AT. DESIGN: A double-blind, randomized, placebo-controlled clinical trial. SETTING: Sports medicine department at a district general hospital. PATIENTS: Sixty-two patients with clinically diagnosed chronic midportion AT were included and randomized into the intervention group (HVI-group, n = 30) and placebo group (n = 32). INTERVENTION: A daily calf-muscle exercise program combined with either (1) a HVI (HVI-group: 50 mL) or (2) a placebo-injection (placebo-group: 2 mL) with a mixture of saline and lidocaine. MAIN OUTCOME MEASURES: Primary outcome was the surface area quantification (SAQ) score (%) of the Doppler flow during a 24-week follow-up period. Secondary outcome was the association between SAQ scores and symptoms [Victorian Institute of Sports Assessment-Achilles (VISA-A)]. Outcomes were measured before, directly after, and 1 hour after the injection and at 2, 6, 12, and 24 weeks of follow-up. RESULTS: There was no significant between-group difference at 24 weeks [-0.1%; 95% confidence interval (CI), -4.9 to 4.7] or at any of the other time points. Change in SAQ score did not correlate with the change in VISA-A score (P = 0.93). CONCLUSION: A HVI does not affect Doppler flow in patients with chronic midportion AT. Also, changes in Doppler flow were not associated with the clinical outcome. These findings challenge the theoretical basis of a HVI. TRIAL REGISTRATION: NCT02996409.

One fifth of patients with Achilles tendinopathy have symptoms after 10 years: A prospective cohort study.

Patients with midportion Achilles tendinopathy (AT) are thought to experience a gradual symptomatic improvement over time. The aim of this study was to prospectively investigate if patients with midportion AT have symptoms at 10-year follow-up. Patients withmidportion AT were invited to complete an online questionnaire 10 years after inclusion in an intervention trial. The primary outcomewas the presence of AT symptoms. Secondary outcomes were: the Victorian Institute of Sports Assessment-Achilles tendinopathy (VISA-A, 0-100) score and sports activity level. Of the 54 patientsincluded, 43 (80%) completed the questionnaire at an average follow-up of 10.4 years. Persisting symptoms were reported by 19%. The mean (standard deviation-SD) VISA-A score improved from 52 (17) at baseline to 79 (21) at 10-years follow-up with a mean change of 27 points (95% confidence interval: 21; 35, p < 0.001). Of the 38 active patients, 16 (42%) returned to their pre-injury level sports,of whom 14 (37%) performed them pain free. One-fifth of patients with conservatively treated midportion AT still have symptoms after 10years. One-third of patients were able to perform sports pain-free atpre-injury level. Patients should be adequately counselled to giverealistic expectations. Trial registration number: clinicaltrials.gov (identifier: NCT00761423).

Association Between T2* Relaxation Times Derived From Ultrashort Echo Time MRI and Symptoms During Exercise Therapy for Patellar Tendinopathy: A Large Prospective Study.

BACKGROUND: Exercise therapy is considered preferential treatment for patellar tendinopathy (PT). However, there is conflicting evidence for structural patellar tendon adaptation in response to exercise therapy and its association with symptoms is weak. PURPOSE: To assess the association between 1) T2* relaxation times and symptom severity; 2) baseline T2* and clinical outcome; and 3) longitudinal T2* changes and clinical outcome in athletes with PT performing exercise therapy. STUDY TYPE: Randomized controlled clinical trial. SUBJECTS: Seventy-six athletes (18-35 years) with clinically diagnosed and ultrasound-confirmed PT. FIELD STRENGTH/SEQUENCE: 3D gradient echo sequence (3.0 T). ASSESSMENT: Patients were enrolled in a randomized trial of progressive tendon-loading exercises (PTLE) versus eccentric exercise therapy (EET). Symptoms were assessed using the Victorian Institute of Sports Assessment (VISA-P) questionnaire. 3D-Ultrashort echo time (UTE)-MRI was acquired at baseline, 12 and 24 weeks. Voxel-wise T2* relaxation times were quantified using mono-exponential and bi-exponential models. T2* analysis was performed in three patellar tendon tissue compartments representing: aligned collagen, degenerative tissue, and interface. STATISTICAL TESTS: Adjusted general linear, mixed-linear models, and generalized estimating equations. RESULTS: We included 76 patients with PT (58 men, mean age 24 ± 4 years); 38 in the PTLE-group and 38 in the EET-group, of which 57 subjects remained eligible for analysis. T2* relaxation times were significantly associated with VISA-P in degenerative and interface tissues of the patellar tendon. No association was found between baseline T2* and VISA-P after 24 weeks (P > 0.29). The estimated mean T2* in degenerative tissue decreased from 14 msec (95%CI: 12-16) at baseline to 13 msec (95%CI: 11-15) at 12 weeks and to 13 msec (95%CI: 10-15) at 24 weeks. The significant decrease in T2* from baseline to 24 weeks was associated with improved clinical outcome. DATA CONCLUSION: Tissue-specific T2* relaxation times, identified with 3D-UTE-MRI, decreased significantly in athletes with patellar tendinopathy performing exercise therapy and this decrease was associated with improved clinical outcome. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 4.

The socio-economic impact of running-related injuries: A large prospective cohort study.

OBJECTIVES: To evaluate the impact of running-related injuries (RRIs) on activities of daily living (ADL), work, healthcare utilization, and estimated costs. DESIGN: Prospective cohort study with data from a randomized controlled trial. METHODS: Adult recreational runners who registered for a running event (distances 5 to 42 km) were included in this study. Minimum follow-up duration was 3 months (preparation, event participation, and post-race period). Injuries were registered using a standardized definition. Primary outcome measure was a standardized 5-item survey on limitations in ADL. The survey data were categorized to the number of injured runners with complete/moderate/no limitations. This outcome was expressed as the percentage of injured runners with any limitation (complete or moderate limitations amalgamated). Secondary outcomes were work absenteeism, the number of healthcare visits per injured runner, and estimated direct medical and indirect costs per participant and per RRI. RESULTS: 1929 runners (mean [SD] age 41 [12] years, 53% men) were included in this study and 883 runners (46%) sustained a RRI during the course of the study. Injured runners reported the highest limitations (% with any limitation) of RRIs during the first week of injury on sports and leisure activities (70%) and transportation activities (23%). 39% of the injured runners visited a healthcare professional. Work absenteeism due to the RRI was reported in 5% of the injured runners. The total mean estimated costs were €74 per RRI and €35 per participant. CONCLUSIONS: Injured runners are mainly limited in their transportation activities and during sports and leisure. While the estimated costs of RRIs are not high when expressed per participant, the absolute costs may be substantial due to the popularity of running.

Effects of eccentric exercises on improving ankle dorsiflexion in soccer players.

PURPOSE: The purpose of this study was to determine the effect of targeted eccentric calf muscle exercises compared to regular training on ankle dorsiflexion in healthy adolescent soccer players with a decreased ankle dorsiflexion. METHODS: Male adolescent players (aged 14-21 years) from two professional soccer clubs were evaluated with the Weight Bearing Dorsiflexion Lunge Test (WBDLT) at baseline and after 12 weeks of this prospective controlled study. One club served as the control group and the other as the intervention group. Players with decreased ankle dorsiflexion (WBDLT) ≤ 10 cm) performed stretching and eccentric calf muscle exercises three times per week next to regular training in the intervention group, and performed only regular training in the control group. Primary outcome was the between-group difference in change in WBDLT between baseline and 12 weeks. RESULTS: Of 107 eligible players, 47(44 %) had a decreased ankle dorsiflexion. The WBDLT (± standard deviation) increased in the intervention group from 7.1 (± 1.8) to 7.4 (± 2.4) cm (95 % Confidence Interval (CI)[-0.493 to 1.108], p = 0.381) and in the control group from 6.1 (± 2.4) to 8.2 (± 2.9) cm (95 % CI [1.313 to 2.659], p < 0.001). The difference in change of WBDLT between both groups was statistically significant (95 % CI [-2.742 to -0.510], p = 0.005). CONCLUSIONS: Targeted eccentric calf muscle exercises do not increase ankle dorsiflexion in healthy adolescent soccer players. Compared to regular training, eccentric exercises even resulted in a decreased calf muscle flexibility. TRIAL REGISTRATION: This trial was registered retrospectively on the 7th of September 2016 in The Netherlands Trial Register (ID number: 6044).

Effectiveness of progressive tendon-loading exercise therapy in patients with patellar tendinopathy: a randomised clinical trial.

OBJECTIVE: To compare the effectiveness of progressive tendon-loading exercises (PTLE) with eccentric exercise therapy (EET) in patients with patellar tendinopathy (PT). METHODS: In a stratified, investigator-blinded, block-randomised trial, 76 patients with clinically diagnosed and ultrasound-confirmed PT were randomly assigned in a 1:1 ratio to receive either PTLE or EET. The primary end point was clinical outcome after 24 weeks following an intention-to-treat analysis, as assessed with the validated Victorian Institute of Sports Assessment for patellar tendons (VISA-P) questionnaire measuring pain, function and ability to play sports. Secondary outcomes included the return to sports rate, subjective patient satisfaction and exercise adherence. RESULTS: Patients were randomised between January 2017 and July 2019. The intention-to-treat population (mean age, 24 years, SD 4); 58 (76%) male) consisted of patients with mostly chronic PT (median symptom duration 2 years). Most patients (82%) underwent prior treatment for PT but failed to recover fully. 38 patients were randomised to the PTLE group and 38 patients to the EET group. The improvement in VISA-P score was significantly better for PTLE than for EET after 24 weeks (28 vs 18 points, adjusted mean between-group difference, 9 (95% CI 1 to 16); p=0.023). There was a trend towards a higher return to sports rate in the PTLE group (43% vs 27%, p=0.13). No significant between-group difference was found for subjective patient satisfaction (81% vs 83%, p=0.54) and exercise adherence between the PTLE group and EET group after 24 weeks (40% vs 49%, p=0.33). CONCLUSIONS: In patients with PT, PTLE resulted in a significantly better clinical outcome after 24 weeks than EET. PTLE are superior to EET and are therefore recommended as initial conservative treatment for PT.

Which treatment is most effective for patients with Achilles tendinopathy? A living systematic review with network meta-analysis of 29 randomised controlled trials.

OBJECTIVE: To provide a consistently updated overview of the comparative effectiveness of treatments for Achilles tendinopathy. DESIGN: Living systematic review and network meta-analysis. DATA SOURCES: Multiple databases including grey literature sources were searched up to February 2019. STUDY ELIGIBILITY CRITERIA: Randomised controlled trials examining the effectiveness of any treatment in patients with both insertional and/or midportion Achilles tendinopathy. We excluded trials with 10 or fewer participants per treatment arm or trials investigating tendon ruptures. DATA EXTRACTION AND SYNTHESIS: Reviewers independently extracted data and assessed the risk of bias. We used the Grading of Recommendations Assessment, Development and Evaluation to appraise the certainty of evidence. PRIMARY OUTCOME MEASURE: The validated patient-reported Victorian Institute of Sport Assessment-Achilles questionnaire. RESULTS: 29 trials investigating 42 different treatments were included. 22 trials (76%) were at high risk of bias and 7 (24%) had some concerns. Most trials included patients with midportion tendinopathy (86%). Any treatment class seemed superior to wait-and-see for midportion Achilles tendinopathy at 3 months (very low to low certainty of evidence). At 12 months, exercise therapy, exercise+injection therapy and exercise+night splint therapy were all comparable with injection therapy for midportion tendinopathy (very low to low certainty). No network meta-analysis could be performed for insertional Achilles tendinopathy. SUMMARY/CONCLUSION: In our living network meta-analysis no trials were at low risk of bias and there was large uncertainty in the comparative estimates. For midportion Achilles tendinopathy, wait-and-see is not recommended as all active treatments seemed superior at 3-month follow-up. There seems to be no clinically relevant difference in effectiveness between different active treatments at either 3-month or 12-month follow-up. As exercise therapy is easy to prescribe, can be of low cost and has few harms, clinicians could consider starting treatment with a calf-muscle exercise programme. PROSPERO REGISTRATION NUMBER: CRD42018086467.

Dutch multidisciplinary guideline on Achilles tendinopathy.

OBJECTIVE: To provide a comprehensive, evidence-based overview of the risk factors, prevention, diagnosis, imaging, treatment and prognosis for Achilles tendinopathy. To make clinical recommendations for healthcare practitioners and patients. DESIGN: Comprehensive multidisciplinary guideline process funded by the Quality Foundation of the Dutch Federation of Medical Specialists. This process included a development, commentary and authorisation phase. Patients participated in every phase. DATA SOURCES: Multiple databases and existing guidelines were searched up to May 2019. Information from patients, healthcare providers and other stakeholders were obtained using a digital questionnaire, focus group interview and invitational conference. STUDY ELIGIBILITY CRITERIA: Studies on both insertional and/or midportion Achilles tendinopathy were eligible. Specific eligibility criteria were described per module. DATA EXTRACTION AND SYNTHESIS: To appraise the certainty of evidence, reviewers extracted data, assessed risk of bias and used the Grading of Recommendations Assessment, Development and Evaluation method, where applicable. Important considerations were: patient values and preferences, costs, acceptability of other stakeholders and feasibility of implementation. Recommendations were made based on the results of the evidence from the literature and the considerations. PRIMARY OUTCOME MEASURE: The primary and secondary outcome measures were defined per module and defined based on the input of patients obtained in collaboration with the Netherlands Patient Federation and healthcare providers from different professions. RESULTS: Six specific modules were completed: risk factors and primary prevention, diagnosis, imaging, treatment prognosis and secondary prevention for Achilles tendinopathy. SUMMARY/CONCLUSION: Our Dutch multidisciplinary guideline on Achilles tendinopathy provides six modules developed according to the standards of the Dutch Federation of Medical Specialists. Evidence-based recommendations for clinical practice are given for risk factors, prevention, diagnosis, imaging, treatment and prognosis. This guideline can assist healthcare providers and patients in clinical practice.

Effect of Platelet-Rich Plasma Injections vs Placebo on Ankle Symptoms and Function in Patients With Ankle Osteoarthritis: A Randomized Clinical Trial.

Importance: Approximately 3.4% of adults have ankle (tibiotalar) osteoarthritis and, among younger patients, ankle osteoarthritis is more common than knee and hip osteoarthritis. Few effective nonsurgical interventions exist, but platelet-rich plasma (PRP) injections are widely used, with some evidence of efficacy in knee osteoarthritis. Objective: To determine the effect of PRP injections on symptoms and function in patients with ankle osteoarthritis. Design, Setting, and Participants: A multicenter, block-randomized, double-blinded, placebo-controlled clinical trial performed at 6 sites in the Netherlands that included 100 patients with pain greater than 40 on a visual analog scale (range, 0-100) and tibiotalar joint space narrowing. Enrollment began on August 24, 2018, and follow-up was completed on December 3, 2020. Interventions: Patients were randomly assigned (1:1) to receive 2 ultrasonography-guided intra-articular injections of either PRP (n = 48) or placebo (saline; n = 52). Main Outcomes and Measures: The primary outcome was the validated American Orthopaedic Foot and Ankle Society score (range, 0-100; higher scores indicate less pain and better function; minimal clinically important difference, 12 points) over 26 weeks. Results: Among 100 randomized patients (mean age, 56 years; 45 [45%] women), no patients were lost to follow-up for the primary outcome. Compared with baseline values, the mean American Orthopaedic Foot and Ankle Society score improved by 10 points in the PRP group (from 63 to 73 points [95% CI, 6-14]; P < .001) and 11 points in the placebo group (from 64 to 75 points [95% CI, 7-15]; P < .001). The adjusted between-group difference over 26 weeks was -1 ([95% CI, -6 to 3]; P = .56). One serious adverse event was reported in the placebo group, which was unrelated to the intervention; there were 13 other adverse events in the PRP group and 8 in the placebo group. Conclusions and Relevance: Among patients with ankle osteoarthritis, intra-articular PRP injections, compared with placebo injections, did not significantly improve ankle symptoms and function over 26 weeks. The results of this study do not support the use of PRP injections for ankle osteoarthritis. Trial Registration: Netherlands Trial Register: NTR7261.

Tissue-Specific T2 * Biomarkers in Patellar Tendinopathy by Subregional Quantification Using 3D Ultrashort Echo Time MRI.

BACKGROUND: Quantitative MRI of patellar tendinopathy (PT) can be challenging due to spatial variation of T2 * relaxation times. PURPOSE: 1) To compare T2 * quantification using a standard approach with analysis in specific tissue compartments of the patellar tendon. 2) To evaluate test-retest reliability of different methods for fitting ultrashort echo time (UTE)-relaxometry data. STUDY TYPE: Prospective. SUBJECTS: Sixty-five athletes with PT. FIELD STRENGTH/SEQUENCE: 3D UTE scans covering the patellar tendon were acquired using a 3.0T scanner and a 16-channel surface coil. ASSESSMENT: Voxelwise median T2 * was quantified with monoexponential, fractional-order, and biexponential fitting. We applied two methods for T2 * analysis: first, a standard approach by analyzing all voxels covering the proximal patellar tendon. Second, within subregions of the patellar tendon, by using thresholds on biexponential fitting parameter percentage short T2 * (0-30% for mostly long T2 *, 30-60% for mixed T2 *, and 60-100% for mostly short T2 *). STATISTICAL TESTS: Average test-retest reliability was assessed in three athletes using coefficients-of-variation (CV) and coefficients-of-repeatability (CR). RESULTS: With standard image analysis, we found a median [interquartile range, IQR] monoexponential T2 * of 6.43 msec [4.32-8.55] and fractional order T2 * 4.39 msec [3.06-5.78]. The percentage of short T2 * components was 52.9% [35.5-69.6]. Subregional monoexponential T2 * was 13.78 msec [12.11-16.46], 7.65 msec [6.49-8.61], and 3.05 msec [2.52-3.60] and fractional order T2 * 11.82 msec [10.09-14.44], 5.14 msec [4.25-5.96], and 2.19 msec [1.82-2.64] for 0-30%, 30-60%, and 60-100% short T2 *, respectively. Biexponential component short T2 * was 1.693 msec [1.417-2.003] for tissue with mostly short T2 * and long T2 * of 15.79 msec [13.47-18.61] for mostly long T2 *. The average CR (CV) was 2 msec (15%), 2 msec (19%) and 10% (22%) for monoexponential, fractional order and percentage short T2 *, respectively. DATA CONCLUSION: Patellar tendinopathy is characterized by regional variability in binding states of water. Quantitative multicompartment T2 * analysis in PT can be facilitated using a voxel selection method based on using biexponential fitting parameters. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 1 J. Magn. Reson. Imaging 2020;52:420-430.

The association between patellar tendon stiffness measured with shear-wave elastography and patellar tendinopathy-a case-control study.

OBJECTIVES: (1) To determine the association between patellar tendon stiffness and the presence of patellar tendinopathy (PT). (2) To evaluate the reliability of shear-wave elastography (SWE). METHODS: Participants were consecutively enrolled between January 2017 and June 2019. PT was diagnosed clinically and confirmed by either grayscale US or power Doppler US, or both. Controls had no history of anterior knee pain and no clinical signs of PT. Patellar tendon stiffness (kilopascal, kPa) was assessed using SWE. Logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). Reliability analyses included coefficients-of-variation (CV), coefficients-of-repeatability (CR), intraclass correlation coefficient (ICC) for intraobserver and interobserver reliability, and Bland-Altman analysis. RESULTS: In total, 76 participants with PT (58 men, mean age 24.4 ± 3.8 years) and 35 asymptomatic controls (16 men, mean age 21.5 ± 3.8 years) were included. Univariate analyses (OR 1.094, 95% CI 1.061-1.128, p < .001) and adjusted multivariate analyses (OR 1.294, 95% CI 1.044-1.605, p = .018) showed that athletes with PT had significantly increased patellar tendon stiffness. ICC for intraobserver reliability was 0.95 (95% CI 0.92-0.97), CR (CV) 12 kPa (10%) and 0.79 (95% CI 0.65-0.88), CR (CV) 18 kPa (21%) for interobserver reliability. Mean differences from Bland-Altman analysis were 5.6 kPa (95% CI 3.1-8.1, p < .001) for intraobserver reliability and 4.6 kPa (95% CI 1.9-7.2, p < .001) for interobserver reliability. CONCLUSIONS: PT is associated with significantly higher patellar tendon stiffness. SWE measurements demonstrate excellent intraobserver reliability and good interobserver reliability. Therefore, SWE is a promising tool to implement in longitudinal studies and future studies should evaluate its prognostic value and utility as a monitoring tool in athletes with PT. KEY POINTS: • Patellar tendon stiffness measured with shear-wave elastography (SWE) is higher in athletes with patellar tendinopathy than in healthy controls, also after adjusting for potential confounders. • Excellent intraobserver reliability and good interobserver reliability were found for the quantitative assessment of patellar tendon stiffness using SWE.

How many runners with new-onset Achilles tendinopathy develop persisting symptoms? A large prospective cohort study.

BACKGROUND: Achilles tendinopathy (AT) occurs in half of the elite runners. AT is a difficult-to-treat tendon disease, which may progress from new onset to a chronic state. It is unknown how many runners with new-onset AT develop persisting symptoms and which prognostic factors are associated with this course. OBJECTIVE: To describe how many runners develop persisting symptoms 1 year after onset of reactive AT. STUDY DESIGN: Prospective cohort study. METHODS: Runners registering for a Dutch running event (5-42.2 km) were eligible for inclusion. Runners reporting new-onset AT between registration for the running event and 1 month after received a 1-year follow-up questionnaire. The 1-year follow-up questionnaire inquired about persisting symptoms (yes/no), running activity, and metabolic disorders. We calculated the percentage of runners with persisting symptoms and performed a multivariable logistic regression analysis to study the association between potential prognostic factors and persisting symptoms. RESULTS: Of 1929 participants, 100 runners (5%) reported new-onset AT. A total of 62 runners (62%) filled in the 1-year follow-up questionnaire. Persisting symptoms were reported by 20 runners (32%). A higher running distance per week before new-onset AT was associated with a lower risk of developing persisting symptoms (odds ratio (OR): 0.9, 95% confidence interval (CI): [0.9;1.0]). There was a positive trend toward an association between metabolic disorders and persisting symptoms (OR: 5.7, 95% CI: [0.9;36.2]). CONCLUSION: One third of runners develop persisting symptoms 1 year after new-onset AT. Interestingly, a higher running distance per week before new-onset AT potentially lowers the risk of developing persisting symptoms.