Tendon disorders are a major problem for participants in competitive and recreational sports. To try to determine whether the histopathology underlying these conditions explains why they often prove recalcitrant to treatment, we reviewed studies of the histopathology of sports-related, symptomatic Achilles, patellar, extensor carpi radialis brevis and rotator cuff tendons. The literature indicates that healthy tendons appear glistening white to the naked eye and microscopy reveals a hierarchical arrangement of tightly packed, parallel bundles of collagen fibres that have a characteristic reflectivity under polarised light. Stainable ground substance (extracellular matrix) is absent and vasculature is inconspicuous. Tenocytes are generally inconspicuous and fibroblasts and myofibroblasts absent. In stark contrast, symptomatic tendons in athletes appear grey and amorphous to the naked eye and microscopy reveals discontinuous and disorganised collagen fibres that lack reflectivity under polarised light. This is associated with an increase in the amount of mucoid ground substance, which is confirmed with Alcian blue stain. At sites of maximal mucoid change, tenocytes, when present, are plump and chondroid in appearance (exaggerated fibrocartilaginous metaplasia). These changes are accompanied by the increasingly conspicuous presence of cells within the tendon tissue, most of which have a fibroblastic or myofibroblastic appearance (smooth muscle actin is demonstrated using an avidin biotin technique). Maximal cellular proliferation is accompanied by prominent capillary proliferation and a tendency for discontinuity of collagen fibres in this area. Often, there is an abrupt discontinuity of both vascular and myofibroblastic proliferation immediately adjacent to the area of greatest abnormality. The most significant feature is the absence of inflammatory cells. These observations confirm that the histopathological findings in athletes with overuse tendinopathies are consistent with those in tendinosis--a degenerative condition of unknown aetiology. This may have implications for the prognosis and timing of a return to sport after experiencing tendon symptoms. As the common overuse tendon conditions are rarely, if ever, caused by 'tendinitis', we suggest the term 'tendinopathy' be used to describe the common overuse tendon conditions. We conclude that effective treatment of athletes with tendinopathies must target the most common underlying histopathology, tendinosis, a noninflammatory condition.

Histopathology of common tendinopathies. Update and implications for clinical management.

Background Despite the popularity of microfracture as a first-line treatment for articular cartilage defects in the knee, systematic information on its clinical efficacy for articular cartilage repair and long-term improvement of knee function is not available. Hypothesis Systematic analysis of the existing clinical literature of microfracture in the knee can improve the understanding of the advantages and limitations of this cartilage repair technique and can help to optimize its indications and clinical outcomes. Study design Systematic review. Methods A comprehensive literature search was performed using established search engines (MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials) to identify original human studies of articular cartilage repair with microfracture. Modified Coleman Methodology Scores were used to analyze the quality of the existing studies. Clinical efficacy of articular cartilage repair was evaluated by systematic analysis of short- and long-term functional outcome scores, macroscopic and microscopic repair cartilage quality, and findings of postoperative magnetic resonance imaging. Results Twenty-eight studies describing 3122 patients were included in the review. The average follow-up was 41 months, with only 5 studies reporting follow-up of 5 years or more. Six studies were randomized controlled trials and the mean Coleman Methodology Score was 58 (range, 22-97). Microfracture effectively improved knee function in all studies during the first 24 months after microfracture, but the reports on durability of the initial functional improvement were conflicting. Several factors were identified that affected clinical outcome. Defect fill on magnetic resonance imaging was highly variable and correlated with functional outcome. Macroscopic repair cartilage quality positively affected long-term failure rate, while the influence of histologic repair tissue quality remained inconclusive. Conclusion This systematic analysis shows that microfracture provides effective short-term functional improvement of knee function but insufficient data are available on its long-term results. Shortcomings of the technique include limited hyaline repair tissue, variable repair cartilage volume, and possible functional deterioration. The quality of the currently available data on micro-fracture is still limited by the variability of results and study designs. Further well-designed studies are needed to determine the long-term efficacy of microfracture and to define its specific clinical indications compared to other cartilage repair techniques.

Clinical Efficacy of the Microfracture Technique for Articular Cartilage Repair in the Knee An Evidence-Based Systematic Analysis

BackgroundThis is a systematic review of studies on the prevalence of osteoarthritis in the tibiofemoral joint more than 10 years after an anterior cruciate ligament injury, the radiologic classification methods used, and risk factors for development of knee osteoarthritis.MethodsA systematic search was performed in PubMed, EMBASE, and AMED. Inclusion criteria were studies involving patients with anterior cruciate ligament injury, either isolated or combined with medial collateral ligament or meniscal injury and either surgically or nonsurgically treated, and a minimum 10-year follow-up with radiologic assessment. Methodological quality was evaluated using a modified version of the Coleman methodology score.ResultsSeven prospective and 24 retrospective studies were included. The mean modified Coleman methodology score was 52 of 90. Reported prevalence of knee osteoarthritis for subjects with isolated anterior cruciate ligament injury was between 0% and 13%. For subjects with anterior cruciate ligament and...

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Knee Osteoarthritis After Anterior Cruciate Ligament Injury A Systematic Review

BackgroundThe prevalence of jumper's knee across different sports has not been examined, and it is not known if there is a gender difference. Data from surgical case series indicate that there may be a high prevalence in sports with high speed and power demands.HypothesisThe aim of this study was to estimate the prevalence of jumper's knee in different sports among female and male athletes and to correlate the prevalence to the loading characteristics of the extensor mechanism in these sports.Study DesignCross-sectional study; Level of evidence, 4.MethodsThe authors examined approximately 50 Norwegian male and female athletes at the national elite level from each of the following 9 sports: athletics (male athletes: high jump, 100- and 200-m sprint), basketball (male athletes), ice hockey (male athletes), volleyball (male athletes), orienteering (male athletes), road cycling (male athletes), soccer (male and female athletes), team handball (male and female athletes), and wrestling (male athletes). The exam...

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Prevalence of Jumper's Knee among Elite Athletes from Different Sports: A Cross-sectional Study:

The proper design and implementation of a study as well as a balanced and well-supported evaluation and interpretation of its main findings are of crucial importance when reporting and disseminating research Also accountability, funding acknowledgement and adequately declaring any conflict of interest play a major role in science Since the Muscles, Ligaments and Tendons Journal (MLTJ) is committed to the highest scientific and ethical standards, we encourage all Authors to take into account and to comply, as much as possible, to the contents and issues discussed in this official editorial This could be useful for improving the quality of the manuscripts, as well as to stimulate interest and debate and to promote constructive change, reflecting upon uses and misuses within our disciplines belonging to the field of "Clinical and Sport - Science Research"

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Muscles, Ligaments and Tendons Journal - Basic principles and recommendations in clinical and field Science Research: 2016 Update.

Patellar tendinopathy is often treated surgically after failure of conservative treatment but clinical experience suggests that results are not uniformly excellent. The aim of this review was to (i) identify the different surgical techniques that have been reported and compare their success rates, and (ii) critically assess the methodology of studies that have reported surgical outcomes. Twenty-three papers and two abstracts were included in the review. Surgical procedures were categorized and outcomes summarized. Using ten criteria, an overall methodology score was derived for each paper. Criteria for which scores were generally low (indicating methodological deficiency) concerned the type of study, subject selection process and outcome measures. We found a negative correlation between papers’ reported success rates and overall methodology scores (r=−0.57, P<0.01). There was a positive correlation between year of publication and overall methodology score (r=0.68, P<0.001). We conclude that study methodology may influence reported surgical outcome. We suggest practical guidelines for improving study design in this area of clinical research, as improved study design would provide clinicians with a more rigorous evidence-base for treating patients who have recalcitrant patellar tendinopathy.

Studies of surgical outcome after patellar tendinopathy: clinical significance of methodological deficiencies and guidelines for future studies. Victorian Institute of Sport Tendon Study Group.

Jl Cook

Papers

Studies of surgical outcome after patellar tendinopathy: clinical significance of methodological deficiencies and guidelines for future studies. Victorian Institute of Sport Tendon Study Group.