Ultrasound Characterization of Patellar Tendon in Non-Elite Sport Players with Painful Patellar Tendinopathy: Absolute Values or Relative Ratios? A Pilot Study

Determination of differences in ultrasound parameters for patellar tendons in males with unilateral patellar tendinopathy-An ancillary analysis of data from two randomized controlled trials

PURPOSE

To investigate power Doppler (PD) activity and tendon structure (between the injured and contralateral limb) in patients with unilateral patellar tendinopathy (PT) using ultrasonography (US). Secondly, the aim was to determine the intra-rater reliability of the PD activity and tendon structure.

METHODS

This study analyzed US baseline data from 57 male participants with symptomatic unilateral PT who had been enrolled in one of two randomized clinical trials. Data were analyzed to examine if systematic differences existed between injured and contralateral limbs using Fiji ImageJ.

RESULTS

The PD activity of the symptomatic tendon was larger 25.6 (Q1 = 14.9; Q3 = 41.6) mm2 than the asymptomatic 0 (Q1 = 0.0; Q3 = 0.0) mm2 (p < 0.001). There was a significantly greater tendon thickness at the proximal (2.5 mm 95% CI [2.0; 3.0]), mid (0.8 mm 95% CI [0.5; 1.1]), and distal (0.2 mm 95% CI [0.1; 0.4]) part of the tendon for the symptomatic compared to the asymptomatic tendon. Intra-rater reliability for PD activity and tendon structure ranged from moderate-to-excellent (0.74; 0.99).

CONCLUSION

These results provide mean estimates for tendon thickness of symptomatic and asymptomatic tendons, that can be used for clinicians to reliably estimate pathological tendon thickness.

Does the ultrasound imaging predict lower limb tendinopathy in athletes: a systematic review

BACKGROUND

To conduct a systematic review looking into the possibility of US imaging to anticipate and identify future patellar or Achilles tendinopathy symptoms.

METHODS

The studies that were taken into consideration for this review were prospective studies that employed baseline US imaging of the patellar OR Achilles tendons in asymptomatic patients and follow-up measures of pain and/or function. Two impartial reviewers evaluated the study's quality using the Critical Appraisal Skills Programme instrument.

RESULTS

Participants in the included studies in this review came from various sports. The systematic review revealed a link between baseline tendon abnormalities in the US and a higher chance of developing both patellar and Achilles tendinopathy as well as their future occurrence. Nine of the included studies examined the patellar tendon alone, eight the patellar and Achilles tendon together, and four the Achilles tendon exclusively. For both tendons, US administration is done in a largely consistent manner. The tendon abnormalities of tendon thickness, hypoechogenicity and vascularity at baseline were associated with an increased risk of both Achilles and patellar tendinopathy.

CONCLUSIONS

This systematic review shows that abnormal tendon structures seen by US in asymptomatic persons can predict the development of tendinopathy.

Effect of Physical Parameters and Training Load on Patellar Tendon Stiffness in Professional Athletes

BACKGROUND

Injuries of the patellar tendon commonly occur as a result of mechanical loading of the tendon during physical activity. Shear wave elastography (SWE) is an established technique for assessing tendon stiffness, and has good interindividual reliability. The aim of this study was to investigate the impacts of physical parameters and different sports on patellar tendon stiffness in professional athletes using SWE.

METHODS

Standardized patellar tendon SWE was performed in a relaxed supine position with a small roll under the knee (20° flexion) in 60 healthy professional athletes (30 female, 30 male). Multiple linear regression was performed for patellar tendon stiffness including gender, age, body mass index (BMI), and type of sport.

RESULTS

Patellar tendon stiffness showed no significant difference between female (3.320 m/s) and male (3.416 m/s) professional athletes. Mean age (female: 20.53 years; male: 19.80 years) and BMI (female: 23.24 kg/m2; male: 23.52 kg/m2) were comparable. Female professional athletes with oral contraceptive (OC) intake showed higher patellar tendon stiffness than athletes without OC intake (3.723 versus 3.017; p = 0.053), but not significantly.

CONCLUSION

In professional athletes, there are no significant differences in patellar tendon stiffness according to gender, age, BMI and type of sport (handball, volleyball, soccer, sprint, hammer throw). Oral contraceptives may not have an impact on patellar tendon stiffness in female athletes. Further studies are necessary.

Differences in Knee Extensors’ Muscle–Tendon Unit Passive Stiffness, Architecture, and Force Production in Competitive Cyclists Versus Runners

To describe the possible effects of chronic specific exercise training, the present study compared the anthropometric variables, muscle–tendon unit (MTU) architecture, passive stiffness, and force production capacity between a group of competitive cyclists and runners. Twenty-seven competitive male cyclists (n = 16) and runners (n = 11) participated. B-mode ultrasound evaluation of the vastus lateralis muscle and patellar tendon as well as passive stiffness of the knee extensors MTU were assessed. The athletes then performed a test of knee extensor maximal voluntary isometric contractions. Cyclists displayed greater thigh girths, vastus lateralis pennation angle and muscle thickness, patellar tendon cross-sectional area, and MTU passive stiffness than runners (P < .05). Knee extensor force production capacity also differed significantly, with cyclists showing greater values compared with runners (P < .05). Overall, the direct comparison of these 2 populations revealed specific differences in the MTU, conceivably related to the chronic requirements imposed through the training for the different disciplines.