Clinical Outcomes and Tendon Structure at 3- to 4-Year Follow-up After Exercise-Based Treatment of Patellar Tendinopathy: A Prospective Study.

Background: The long-term recovery (in years) of patellar tendinopathy treated with loading-based rehabilitation remains largely unknown.

Purpose: To examine the clinical outcome and tendon structure years after exercise-based treatment of chronic patellar tendinopathy.

Study Design: Case series; Level of evidence, 4.

Assessment of the Psychometric Properties of the Danish VISA-P.

Purpose: The objective of the current study was to conduct a rigorous assessment of the psychometric properties of the Victorian Institute of Sports Assessment-patellar tendinopathy (VISA-P).

Methods: Rasch analysis, confirmatory factor analysis (CFA), and multivariable linear regression were used to assess the psychometric properties of the VISA-P questionnaire in 184 Danish patients with patellar tendinopathy who had symptoms ranging from under 3 months to over 1 year. A group of 100 healthy Danish persons was included as a reference for known-group validation.

Disruption of day-to-night changes in circadian gene expression with chronic tendinopathy.

Overuse injury in tendon tissue (tendinopathy) is a frequent and costly musculoskeletal disorder and represents a major clinical problem with unsolved pathogenesis. Studies in mice have demonstrated that circadian clock-controlled genes are vital for protein homeostasis and important in the development of tendinopathy. We performed RNA sequencing, collagen content and ultrastructural analyses on human tendon biopsies obtained 12 h apart in healthy individuals to establish whether human tendon is a peripheral clock tissue and we performed RNA sequencing on patients with chronic tendinopathy to examine the expression of circadian clock genes in tendinopathic tissues.

Pathological Tendon Histology in Early and Chronic Human Patellar Tendinopathy.

The present pilot study investigated the extent of histological tissue changes in both chronic tendinopathy and in individuals that display early clinical signs of tendinopathy. The study included 8 individuals of whom 3 were healthy without any tendon symptoms, 2 had early symptoms (1-2 months), and 3 had chronic symptoms (>3 months) from their patellar tendons. Percutaneous needle biopsy samples were obtained from the affected tendon tissue region.

Habitual side-specific loading leads to structural, mechanical, and compositional changes in the patellar tendon of young and senior lifelong male athletes.

Effects of lifelong physical activity on tendon function have been investigated in cross-sectional studies, but these are at risk of "survivorship" bias. Here, we investigate whether lifelong side-specific loading is associated with greater cross-sectional area (CSA), mechanical properties, cell density (DNA content), and collagen cross-link composition of the male human patellar tendon (PT), in vivo. Nine seniors and six young male lifelong elite badminton players and fencers were included.