Relationships between tendon structure and clinical impairments in patients with patellar tendinopathy

Abstract

The clinical relevance of altered tendon structure in patellar tendinopathy is contested since structural change persists after symptom resolution. The purpose of this study was to explore the relationships between tendon structure and clinical impairments in patellar tendinopathy. In this retrospective, secondary analysis of individuals with patellar tendinopathy (n = 41), tendon structure (thickness, cross‐sectional area [CSA], shear modulus, and viscosity), symptom severity, lower extremity function (counter‐movement jump [CMJ] height), and quadriceps muscle performance (knee extension force and central activation ratio [CAR]) were recorded for the symptomatic limb. Relationships among structure, symptom severity, lower extremity function, and quadriceps muscle performance were examined using sequential regression models. Adjusting for age, sex, body mass index, and pain levels, there were significant positive relationships for thickness (p < 0.001, β = 0.718) and viscosity (p = 0.006, β = 0.496) with CMJ height. There were significant negative relationships between CSA with both CMJ height (p = 0.001, β = −0.538) and CAR (p = 0.04, β = −0.517). This is the first study to demonstrate relationships between tendon structure and lower extremity function or quadriceps muscle performance in patients with patellar tendinopathy. Clinical significance: Since structural changes persist after symptom resolution, addressing these changes may assist in restoring lower extremity function and quadriceps muscle performance.

Persons with Patellar Tendinopathy Exhibit Greater Patellar Tendon Stress during a Single-Leg Landing Task

“…Although the current study provides insight into a potential kinematic contributor to patellar tendon loading in persons with patellar tendinopathy, we only were able to explain 26% of the variance in peak maximum principal stress. Other factors such as tendon structural characteristics (i.e., cross-sectional area, length) have been suggested to play a role in contributing to patellar tendon stress (33) and should be considered in future investigations. Nonetheless, the current results suggest that multiplane loading of the knee may contribute to the development of patellar tendinopathy.…”

Relationships between surrogate measures of mechanical and psychophysiological load, patellar tendon adaptations, and neuromuscular performance in NCAA division I men's volleyball athletes

“…Conversely, maladaptation may occur in response to suboptimal loading patterns leading to hypoechoic regions and increases in thickness (26). Tendon thickening has been established as an adaptive mechanism allowing for more efficient transfer of mechanical energy (59) with supporting evidence that patellar tendon thickness is associated with higher countermovement jump height (34). Acute inflammatory responses may partially explain the early stages of tendon pathology (60).…”

“…The utility of monitoring structural changes has been in question due to disassociated time course of symptom resolution and improvements in tissue structure (32,33).. However, clinical impairments in lower extremity neuromuscular function may persist after symptom resolution (34). In addition, asymptomatic abnormalities are a risk factor for the development of future symptoms (35) and may alter neuromuscular function (30, 34) thereby warranting further investigation into the management of volleyball athlete load and monitoring of tendon structure.…”

Reliability of Continuous Shear Wave Elastography in the Pathological Patellar Tendon

“…3 Tendon structure is associated with function and outcomes after injury, and may be readily assessed in a clinical setting. [4][5][6][7][8] Evaluating the structural changes in the injured patellar tendon may assist in identifying the underlying pathophysiology as well as guide clinical care after injury.Patellar tendinopathy (PT) is an overuse injury of the patellar tendon typically associated with activities involving plyometrics. 9,10…”

“…One of the themes observed across pathological tendons, regardless of the source of injury, are morphological alterations (eg, tendon thickening, larger cross‐sectional areas, or hypoechoic regions identified on sonographic evaluations) to the tendon 3 . Tendon structure is associated with function and outcomes after injury, and may be readily assessed in a clinical setting 4–8 . Evaluating the structural changes in the injured patellar tendon may assist in identifying the underlying pathophysiology as well as guide clinical care after injury.…”