RESUMEN
Appropriate management of patellar tendinopathy requires distinguishing between inflammatory and degenerative conditions, often difficult because tendon thickening can be a normal or pathological adaptation, and micromorphology is not observable on clinical imaging. The purpose of this study was to quantitatively examine patellar tendon micro- and macromorphology in volleyball athletes and relate those findings to reported symptoms. Longitudinal ultrasound images of proximal and distal patellar tendons were acquired from 84 male elite volleyball athletes (44 symptomatic, 40 asymptomatic) and 10 asymptomatic nonathlete controls. Micromorphology was determined using two-dimensional Fast Fourier Transform analysis providing a discriminating peak spatial frequency parameter (PSF). Macromorphology (patellar tendon thickness) was measured using Image J software. All athletes regardless of symptoms had thicker proximal tendons compared to nonathletes, suggesting a normal adaptation to training loads. However, symptomatic athletes demonstrated lower PSF than asymptomatic athletes and nonathletes at the proximal tendon, suggesting greater collagen disorganization, and tendon degeneration rather than inflammation. Only symptomatic athletes had thicker distal tendons than nonathletes, but there was no difference in PSF distally. Diagnostic ultrasound enhances the understanding of the micromorphology of patellar tendons, supporting the rationale for management that remodels the degenerated tendon instead of treating inflammation.
Asunto(s)
Ligamento Rotuliano/diagnóstico por imagen , Tendinopatía/diagnóstico por imagen , Voleibol/fisiología , Análisis de Varianza , Enfermedades Asintomáticas , Estudios de Casos y Controles , Análisis de Fourier , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Ultrasonografía , Adulto JovenRESUMEN
Estrogen concentration has been suggested to play a role in tendon abnormalities and injury. In physically active postmenopausal women, hormone replacement therapy (HRT) has been suggested to decrease tendon diameter. We hypothesized that HRT use and physical activity are associated with Achilles tendon size and tissue structure. The study applied cotwin analysis of fourteen 54- to 62-yr-old identical female twin pairs with current discordance for HRT use for an average of 7 yr. Achilles tendon thickness and cross-sectional areas were determined by ultrasonography, and tendon structural organization was analyzed from the images using linear discriminant analysis (LDA). Maximal voluntary and twitch torques from plantar flexor muscles were measured. Serum levels of estradiol, estrone, testosterone, and sex hormone binding globulin were analyzed. Total daily metabolic equivalent score (MET-h/day) was calculated from physical activity questionnaires. Results showed that, in five physically active (MET > 4) pairs, the cotwins receiving HRT had greater estradiol level (P = 0.043) and smaller tendon cross-sectional area than their sisters (63 vs. 71 mm(2), P = 0.043). Among all pairs, Achilles tendon thickness and cross-sectional area did not significantly differ between HRT using and nonusing twin sisters. Intrapair correlation for Achilles tendon thickness was high, despite HRT use discordance (r = 0.84, P < 0.001). LDA distinguished different tendon structure only from two of six examined twin pairs who had a similar level of physical activity. In conclusion, the effect of HRT on Achilles tendon characteristics independent of genetic confounding may be present only in the presence of sufficient physical activity. In physically active twin pairs, the higher level of estrogen seems to be associated with smaller tendon size.
Asunto(s)
Tendón Calcáneo/anatomía & histología , Tendón Calcáneo/fisiología , Terapia de Reemplazo de Hormonas , Actividad Motora/fisiología , Tendón Calcáneo/diagnóstico por imagen , Anciano , Colesterol/sangre , Estrógenos/sangre , Estrona/sangre , Femenino , Humanos , Menopausia/fisiología , Persona de Mediana Edad , Contracción Muscular/fisiología , Fuerza Muscular/fisiología , Globulina de Unión a Hormona Sexual/metabolismo , Testosterona/sangre , Gemelos Monocigóticos , UltrasonografíaRESUMEN
The structural characteristics of a healthy tendon are related to the anisotropic speckle patterns observed in ultrasonic images. This speckle orientation is disrupted upon damage to the tendon structure as observed in patients with tendinopathy. Quantification of the structural appearance of tendon shows promise in creating a tool for diagnosing, prognosing, or measuring changes in tendon organization over time. The current work describes a first step taken towards this goal-classification of Achilles tendon images into tendinopathy and control categories. Eight spatial frequency parameters were extracted from regions of interest on tendon images, filtered and classified using linear discriminant analysis. Resulting algorithms had better than 80% accuracy in categorizing tendon image kernels as tendinopathy or control. Tendon images categorized wrongly provided for an interesting clinical association between incorrect classification of tendinopathy kernels as control and the symptom and clinical time history based inclusion criteria. To assess intersession reliability of image acquisition, the first 10 subjects were imaged twice during separate sessions. Test-retest of repeated measures was excellent (tau = 0.996, ICC = (2, 1) = 0.73 with one outlier) indicating a general consistency in imaging techniques.
Asunto(s)
Algoritmos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Reconocimiento de Normas Patrones Automatizadas/métodos , Tendones/diagnóstico por imagen , Ultrasonografía/métodos , Análisis Discriminante , Humanos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , TendinopatíaRESUMEN
Ultrasound speckle has long been recognized as a noise source in diagnostic imaging. The advent of three-dimensional imaging and flow detection requires the characterization of the three-dimensional acoustical speckle pattern. Ultrasound data were acquired by using an automated three-dimensional translation stage to measure the radio-frequency (rf) backscatter signals from a volume scattering phantom. The data samples were processed off-line to locate and measure envelope-detected speckle peaks, i.e., local maxima. Results indicate that speckle has a distinctive structure in which three-dimensional peaks can be located and measured. These peaks are brighter on average than the mean speckle brightness level and are uniformly distributed throughout the volume. The lateral breadth of the speckle peaks, defined as the breadth of the -6 dB contour in the lateral-elevational plane, is over twice the width predicted by previous investigators. This is the first attempt to physically measure the breadth of bright spots in the speckle pattern. A rational for the discrepancy between previous theory and the measurement in this paper is given.