Search results for "Patellar tendon"

Bilateral ruptures of the extensor mechanism of the knee: A systematic review

2017

Abstract Introduction We conduct a systematic and qualitative review of the current literature to evaluate studies that described bilateral ruptures of the extensor mechanism of the knee. Methods A comprehensive literature search was performed to evaluate all studies included in the literature until September 2016. Results Fourteen studies with a total of 44 patients met the inclusion criteria. There were 14 patients with CRF (61%), 6 patients were affected by diabetes mellitus (14%) while other 6 patients were obese patients (14%). Conclusion CRF represents the most frequent comorbidity in patients with bilateral quadriceps/patellar tendon ruptures.

Middle patellar tendon to posterior cruciate ligament (PT–PCL) and normalized PT–PCL: New magnetic resonance indices for tibial tubercle position in …

2018

BACKGROUND To demonstrate whether the distance between the middle point of the patellar tendon and posterior cruciate ligament (PT-PCL) calculated on a single axial MR image could be an alternative measure to tibial tubercle-PCL (TT-PCL) distance for TT lateralization without the need of imaging processing. To show that normalization of PT-PCL (nPT-PCL) against the maximum diameter of the tibial plateau may help to identify patients with patellar instability (PI). METHODS MR scans of 30 patients (13 females, age 32 ± 13 years) with known PI and 60 patients (31 females, age 39 ± 19 years) with no history of PI were reviewed. Two operators calculated TT-PCL, and PT-PCL nPT-PCL. Intraclass cor…

Lower strength of the human posterior patellar tendon seems unrelated to mature collagen cross-linking and fibril morphology

2009

The human patellar tendon is frequently affected by tendinopathy, but the etiology of the condition is not established, although differential loading of the anterior and posterior tendon may be associated with the condition. We hypothesized that changes in fibril morphology and collagen cross-linking would parallel differences in material strength between the anterior and posterior tendon. Tendon fascicles were obtained from elective ACL surgery patients and tested micromechanically. Transmission electron microscopy was used to assess fibril morphology, and collagen cross-linking was determined by HPLC and calorimetry. Anterior fascicles were markedly stronger (peak stress: 54.3 ± 21.2 vs.…

Mechanical Properties of Human Patellar Tendon at the Hierarchical levels of Tendon and Fibril

2012

Tendons are strong hierarchical structures, but how tensile forces are transmitted between different levels remains incompletely understood. Collagen fibrils are thought to be primary determinants of whole tendon properties, and therefore we hypothesized that the whole human patellar tendon and its distinct collagen fibrils would display similar mechanical properties. Human patellar tendons ( n = 5) were mechanically tested in vivo by ultrasonography. Biopsies were obtained from each tendon, and individual collagen fibrils were dissected and tested mechanically by atomic force microscopy. The Young's modulus was 2.0 ± 0.5 GPa, and the toe region reached 3.3 ± 1.9% strain in whole patellar …

Muscle‐tendon morphology and function following long‐term exposure to repeated and strenuous mechanical loading

2019

We mapped structural and functional characteristics of muscle‐tendon units in a population exposed to very long‐term routine overloading. Twenty‐eight military academy cadets (age = 21.00 ± 1.1 years; height = 176.1 ± 4.8 cm; mass = 73.8 ± 7.0 kg) exposed for over 24 months to repetitive overloading were profiled via ultrasonography with a senior subgroup of them (n = 11; age = 21.4 ± 1.0 years; height = 176.5 ± 4.8 cm; mass = 71.4 ± 6.6 kg) also tested while walking and marching on a treadmill. A group of eleven ethnicity‐ and age‐matched civilians (age = 21.6 ± 0.7 years; height = 176.8 ± 4.3 cm; mass = 74.6 ± 5.6 kg) was also profiled and tested. Cadets and civilians exhibited similar mo…

Structural analysis of rat patellar tendon in response resistance and endurance training.

2009

Little is known about tendon adaptations induced by mechanical loading. Our goal was to evaluate the effects of two different exercise training protocols on adult rat patellar tendon. Ninety-six male Wistar rats were divided into a sedentary group (control), a resistance-trained group and an endurance-trained group. The examinations were performed after 15, 30 and 45 days of training and after 2 weeks of rest since training was stopped. The content of collagen fibers and the cell nuclei number were quantified on tendon cross sections. In order to assess the training effectiveness, we evaluated the heart/body weight ratio, which was higher in 45 day-trained rats than their controls (P<0.01),…

The effects of knee and hip joint angles on patellar tendon loading during quadriceps neuromuscular electrical stimulation

2021

Lower Limb Dominance, Morphology, and Sonographic Abnormalities of the Patellar Tendon in Elite Basketball Players: A Cross-Sectional Study.

2019

Context Patellar tendinopathy is common in basketball players, and structural ultrasound abnormalities can be found in symptomatic and asymptomatic tendons. Lower limb dominance may also be a critical load factor, potentially leading to overloading of the patellar tendon. Objective To describe and compare the prevalence by lower limb dominance of patellar tendons with structural and vascular abnormalities and to describe the morphologic measures of tendons without abnormalities among adult male elite basketball players. Design Cross-sectional study. Setting Medical center of a professional basketball team in the Spanish league. Patients or Other Participants A total of 73 adult male elite …

MRI evaluation to predict tendon size for knee ligament reconstruction.

2017

Background The aim of this study is to evaluate a possible correlation between specific anthropometric parameters and sizes of knee tendons commonly used for ACL reconstruction. We hypothesized that specific clinical and radiological knee measurements could be better tendon sizes predictors than age, gender, height and weight. Materials and methods 100 consecutive patients were enrolled and 77 patients met the inclusion criteria of the study. All patients underwent a MRI of the knee with a 1.5 T super conducting MR System. For each patient, anthropometric data such as gender, height, weight, body mass index (BMI) and knee circumference were recorded. Specific MRI knee measurements were perf…

Healing of the patellar tendon donor defect created after central-third patellar tendon autograft harvest

1999

Patellar tendon donor defect (PTDD) healing after patellar tendon autograft (PTA), was evaluated in 12 lambs (24 knees), by means of conventional histology, immunohistochemistry and image analysis. The results of this study indicate that the PTDD is replaced by a tissue that does not assume the histological characteristics of a normal patellar tendon. Both the Hoffa fat pad (HFP) and the paratenon play an important role in the healing process, although qualitative and quantitative chronological differences were found, which supports the concept of a “two-time process”. The HFP initiates the repair process, and is the main active proliferative tissue compartment during the first week. Once t…