Quantitative analysis of patellar tendon size and structure in asymptomatic professional players: sonographic study

Abstract

SummaryBackground: Ultrasonographic abnormalities of the patellar tendon frequently occur in asymptomatic athletes and it is not always clear whether they precede (and may predict) the development of tendinopathy. Objective: This study aimed to investigate by ultrasonography the prevalence of patellar tendon abnormalities in players of "pallapugno" and to establish whether structural tendon abnormalities predict tendinopathy development. Methods: Ultrasound B-mode images of the patellar tendon of both sides were acquired in fourteen throwers. Qualitative assessments of tendon structure and neovascularization and quantitative assessments of tendon thickness, cross sectional area (CSA), and echo-intensity were performed. Results: Qualitative assessments showed a subclinical tendinopathy of the non-dominant tendon in 5 out of 14 throwers (35% of cases), while quantitative assessments showed abnormalities of the nondominant tendon in 8 out of 14 players (57% of cases). Echo-intensity and CSA were the quantitative variables most discriminant between asymptomatic players without structural tendon abnormalities and those with tendon abnormalities. Two players (2 out of 8 cases: 25%) developed a clinical tendinopathy after a follow-up of six months. Conclusion: The prevalence of subclinical tendinopathy in the non-dominant patellar tendon of throwers was high. Patellar tendon abnormalities at baseline seem to increase the risk of development of subsequent patellar tendinopathy. Level of evidence: II b (individual cohort study).

Quantitative Analysis of Patellar Tendon Abnormality in Asymptomatic Professional “Pallapugno” Players: A Texture-Based Ultrasound Approach

“…For the purpose of this texture-analysis study, 6 images on each side were analyzed as reported in Table 1. The remaining 4 images on each side were employed also for qualitative assessments of neovascularization and tendon structure as reported in [23]. According to the definition as cited in the Introduction [23], 5 subjects out of the 14 were found to be affected by subclinical tendinopathy (i.e., 5 subjects demonstrated the presence of light structural changes in association with at least mild neovascularization or moderate/severe structural changes with/without neovascularization).…”

“…Morphological abnormalities in the tendon ultrasound image, such as increased tendon thickness, neovascularization, and presence of hypoechoic areas, have also been found in a large percentage of asymptomatic athletes [9,11,13,22]. Recently, Giacchino et al [23] also conducted a study of patellar tendon size and structure in throwers and found that the prevalence of subclinical tendinopathy was high in the non-dominant patellar tendon as a possible result of the repeated non-dominant lower limb overload. To do so, the authors arbitrarily defined subclinical tendinopathy as "the presence of either light structural changes in association with at least mild neovascularization or moderate/severe structural changes with/without neovascularization" [23].…”

“…Recently, Giacchino et al [23] also conducted a study of patellar tendon size and structure in throwers and found that the prevalence of subclinical tendinopathy was high in the non-dominant patellar tendon as a possible result of the repeated non-dominant lower limb overload. To do so, the authors arbitrarily defined subclinical tendinopathy as "the presence of either light structural changes in association with at least mild neovascularization or moderate/severe structural changes with/without neovascularization" [23]. In the study, however, the determination of structural changes was done by quantitative assessments of tendon echo intensity and size and by qualitative analysis of the B-mode ultrasound images of both the dominant and non-dominant side, which is a very subjective technique and can depend greatly on the ultrasound scanner settings [24].…”

“…In this study, we aim to quantitatively analyze the presence of patellar tendon abnormality and subclinical tendinopathy in professional asymptomatic players using a texture-based morphological approach and the same image database as presented in [23]. In particular, the study provides quantitative texture features calculated on the images initially used for the determination of a qualitative structure score [23], and analyzes the capability of this approach to discriminate between the dominant and non-dominant side of the player, and to determine the presence of subclinical tendinopathy as defined previously.…”

“…In particular, the study provides quantitative texture features calculated on the images initially used for the determination of a qualitative structure score [23], and analyzes the capability of this approach to discriminate between the dominant and non-dominant side of the player, and to determine the presence of subclinical tendinopathy as defined previously.…”