Ultrasonic characters of entheses and their impact factors in healthy volunteers

Tianwang LI; Jieruo GU; Jie REN; Rongqin ZHENG; Feng HUANG; Yuqiong WU

ABSTRACT

BACKGROUND:

Enthesitis is the most important pathologic change and one of the characteristic manifestations of spondyloarthropathy(SpA). However, its clinical manifestations lack specificity, and medical imaging techniques become an important auxiliary means in its diagnosis. Currently, ultrasound has been applied to examine the entheses of patients with SpA abroad, but so far there is no investigation about the ultrasonic manifestations of entheses in healthy volunteers.

OBJECTIVE:

To comprehend the acoustic imaging manifestations of entheses in healthy volunteers, and primarily investigate the feasibility of ultrasound in detecting entheses and the possible impact factors of acoustic imaging manifestations.

DESIGN:

A nonrandomized inter-controlled trail.SETTING and

PARTICIPANTS:

A total of 30 young healthy workers and medical students who worked or studied in the Third Affiliated Hospital of Sun Yat-sen University were included in our study, including 22 male and 8 female. None of them suffered from any arthropathies or chronic low back pain.INTERVENTION High frequency and Color Doppler ultrasound were adopted to detect 540 entheses of 30 healthy volunteers, the entheseal thicknesses were compared respectively according to left and right sides, as well as the gender. X-ray was used to inspect if there were any abnormal findings at the attaching bones.MAIN OUTCOME

MEASURES:

The thickness, the echo inside entheses, the entourage, the attaching bone and the entheseal blood flow were detected.

RESULTS:

In normal entheses, there was a little lower but equal resonance, in which there was clear funicular fibrin resonance but without blood signal. Most entheses had a little higher membrane resonance, which was clearly divided from entourage. The surface of attaching bone was smooth and continuous. The mean thickness of the lower insertion of rectus femoris tendon, the upper insertion of patellar ligament, the lower insertion of patellar ligament, the lower insertion of tibial collateral ligament, the lower insertion of fibular collateral ligament, the insertion of Achilles tendon and plantar aponeurosis in male volunteers were(0.50 ±0.06), (0. 50 ±0. 07),(0.42±0.04), (0.20±0.03), (0.38±0.04), (0.52±0.07)and (0. 32 ±0.03) cm respectively, while the mean thickness of the corresponding insertions in female volunteers were (0.44 ± 0. 04), (0. 46 ± 0. 03 ),(0.39±0.03), (0.19±0.02), (0.32±0.02), (0.41±0.06)and (0. 28 ± 0.03) cm respectively. All entheses except for the lower insertion of tibial collateral ligament were thicker in male than in female( P ＜ 0. 05 ),but there were no significant differences in the thickness between left and right insertions ( P ＞ 0. 05 ). Calcification, erosion and hyperplasia of the attaching bone or increasing blood flow were found in 11 entheses of 8 volunteers(2.0% of all the 540 entheses detected) . There were 15 items of abnormal signs all together. Some of the abnormal sites had traumatic histories.

CONCLUSION:

The thicknesses are almost the same in the corresponding insertions between left and right sides, but the thicknesses of most insertions in male are thicker than those in female. Stature, body mass and exercise might impact on entheseal thickness. Trauma can cause abnormal acoustic imaging manifestations of entheses. Ultrasound is an available approach to detecting etheses.