Sonography In Diagnosis Of Iliotibial Tract Contracture

Purposes:Iliotibial tract contracture belongs to gluteal muscle contracture(GMC) with mild symptom. Which is More common in young people under the age of20.Its clinical presentation is not typical. Most patients just showed as snapping or feelling strip of sliding over the greater trochanter(GT) during flexion of the hip.Some patient would showed as can not squat with knees together. All patients have no hip muscle atrophy signs in physical examination. The change only can be seen by Pathological examination. You will found nothing change in the muscle and the tissue of hip even by imaging examination.So it is very easy to miss it. There are many reports about imaging diagnosis of gluteal muscle contracture had been posted in the literature.But most of all were focused on the examination of the hip muscles. Iliotibial tract and the junction,which commonly cut off by surgeon for releasing contracture tissue, almost no one mentioned.Therefore,we intend to establish the ultrasound standard of the femoral greater trochanter region iliotibial tract in healthy people.Compared with the standard, we examined suspected patients of iliotibial tract contracture by high frequency ultrasonography.The target of iliotibial tract and junction will be dynamic observed and it’s thickness be recorded. All the video,the imagings and the measured data was statistically analyzed. Finally, the characteristics of high frequency ultrasoun in the diagnosis of iliotibial tract contracture will be summed up.And we hope it can provide patients some guidelines for clinical treatment. 1. The ultrasound standard of the femoral greater trochanter region iliotibial tract in healthy people.1.1. The subjectsOne hundred and twenty asymptomatic volunteers (66men and54women) ranging in age from4to68years participated in the study. Each patient under-went sonographic examination of both knees by radiologists. Verbal consent was obtained from all participants. The volunteers completed a questionnaire, providing their age,weight, and height. Subjects with a history ofpain in the region of the ITT were excluded from the study.The volunteers were divided into two groups according to their age:minor,ranging in ange from4to17years, mean (11.13±3.80) years,60cases,35males and25females; adult, ranging in ange from18to68years, mean (39.18±14.67years),60cases,31males and, Female29cases.1.2. Methods1.2.1. EquipmentColor Doppler ultrasound imaging device which band are Siemens Sequoia512, Siemens Acuson Antares and Philips IE33.All of them are equipped with linear probe(frequency8-14MHz) and DICOM device,which can video and playback of dynamic features.And it will be insure the screenshots and video can be required to prepare the background observed, measured, and statistical analysis..1.2.2. Examination methodThe volunteers lay on the side, both legs extend naturally, oblique probe, and the gluteus maximus fibers take the front line in the same direction, to the greater trochanter as the central region clearly show the interest and the gluteus maximus and the iliotibial tract aponeurosis junction To observe the texture and echo; to front and close to the junction of the greater trochanter of the iliotibial band as a standard section, measure and record.Then observed the other side of iliotibial tract and the junction in the same way.1.3. Statistical analysis We used the Wilcoxon signed rank test to assess for a statistically significant difference in ITT thickness between the left and right knees and the Mann-Whitney test to assess for a significant difference in ITT thickness between men and women. Correlation of ITB thickness with the age, height, and weight of the volunteers was assessed using the Spearman product moment correlation.A p value of less than0.05was considered significant.2. Sonography in diagnosis of iliotibial tract contracture2.1. Case InformationOver a36-month period, we studied sixty-seven iliotibial tract in38consecutive patients with iliotibial tract contracture (27males and11females; age range5-31years; mean,15.63years) confirmed both by pathology and surgery.2.2. Methods2.2.1. EquipmentColor Doppler ultrasound imaging device which band are Siemens Sequoia512, Siemens Acuson Antares and Philips IE33.All of them are equipped with linear probe(frequency8～14MHz) and DICOM device,which can video and playback of dynamic features.And it will be insure the screenshots and video can be required to prepare the background observed, measured, and statistical analysis.2.2.2. Examination method2.2.2.1.Patient lay on the side, both legs extend naturally, oblique probe, and the gluteus maximus fibers take the front line in the same direction, to the greater trochanter as the central region clearly show the interest and the gluteus maximus and the iliotibial tract aponeurosis junction To observe the texture and echo; to front and close to the junction of the greater trochanter of the iliotibial band as a standard section, measure and record.2.2.2.2. With the probe in the transverse plane over the greater trochanter,dynamic sonographic studies were performed during flexion and extension of the hip in the adducted state and with the hip in the adducted and internally rotated state and then in the flexed and externally rotated state.All cases were recorded for analysis latter.2.2.2.3. Then observed the other side of iliotibial tract and the junction in the same way. 1.3. Statistical analysisWe used the Wilcoxon signed rank test to assess for a statistically significant difference in ITT thickness between the left and right knees.A p value of less than0.05was considered significant.Results1. The ultrasound standard of the femoral greater trochanter region iliotibial tract in healthy people.1.1. High frequency ultrasonographic characteristics of femoral greater trochanter region iliotibial tract in healthy volunteers1.1.1. High-frequency ultrasound showed iliotibial tract as a thin and wide band in shape with a clear and hyperechoic fine border. There were a little lower but homo-geneous echoes and clear streak-like fibrilla inside the normal ITT. No blood flow signal was detected in ITT of all volunteers.1.1.2.The internal echo of ITT was lower in minor than in adult. With age increasing, the echo has a gradually enhanced trend.1.1.3.The border between iliotibial tract and the junction of gluteus maximus was unclear.The echo of ITT was stronger than the gluteus maximus. In the section on ultrasound examination, ITT separated upper and lower levels in the cord-like fibers,the border of the junction was unclear, the gluteus maximus "entry" iliotibial tract like spindle-shaped into the two layers of fiber bundles.1.2. The thickness of the normal ITT1.2.1. At the level of the femoral greater trochanter, the thickness of the ITT ranged from1.6to3.7mm, with an overall mean of2.35mm±0.38mm (±standard deviation).1.2.2. There were no different in ITT thickness between left and right side or between man and woman (P>0.05) in both groups. The thickness of the ITT in minor period was thinner than in adulthood. There was a significant difference (Y=-6.939～-6.632,P<0.01) between the two groups on the same side. 1.2.3. Correlation of ITT thicknesses with subject age, weight, and height revealed a statistically significant positively correlation between ITT thickness and subject age, weight, and height in minor period(γ=0.641-0.682, P<0.05). However, there was no significant correlation was found between ITB thickness and subject height, weight in adulthood, but a negative correlation between ITB thickness and subject age (γ=-0.412～-0.391, P<0.05).2. Sonography in diagnosis of iliotibial tract contracture2.1. High frequency ultrasonographic characteristics of contracture iliotibial tract2.1.1. The thickness of the ITT on the ill side ranged from2.6mm to6.1mm, with an overall mean of3.66mm±0.74mm (±standard deviation). There was a significant difference (Y=-2.67, P<0.01) in ITT thickness between the left and right sides in those patients who were unilateral disease.Howevre, There was no significant diffe-rence (Y=-1.20, P>0.05) in those bilateral disease.2.1.2. The thickness of the ITT on the ill side were in different degrees. The filamen-tous fiber structure and hypoechoic tissue in the ITT was disappeared.The abnormal ITT appeared as a hard-strip in shape with heterogeneous echo inside. And it was un-clear with the surrounding tissue.2.1.3. Howere,t he junction of iliotibial tract and gluteus maximus muscle,the normal shape and the structural of junction was irregular.lt was appeared as scleroma in sha-pe with heterogeneous echo inside.2.2. Dynamic imaging characteristics of contracture iliotibial tractWith the probe in the transverse plane over the greater trochanter,dynamic sonographic studies were showed that ITT and the junction crossed the greater trochanter closely as Contracture-like in shape with fast speed.In the dynamic sonographic studies,57cases (85.1%) were resulted in snapping with the hip movements.2.3. The buttocks muscle and soft tissueThere was no atrophy singn in the buttocks muscles of all the patients reported by the physical examination.And the buttocks muscles of all patients were normal inthe sonographic imaging.2.3. Pathology2.3.1. Gross specimen The ITT was showed as contracture strip bundle,its color was pale or gray,and with adhesion to the surrounding tissue.2.3.2. Microscope The fibrous tissue of the contracture ITT became hyaline degeneration, fo-cal hemorrhage. And large areas of dense thick fibrous connective tissue collagencould be visible. The deformation muscle fiber could be seen in the interstitial. Asmall amount of fat tissue filled with between the fibrous tissue.Sometimes you couldsee some inflammatory cells.The gluteus maximus muscle fibers of the junction wasshowed as plasma coagulation, red dye, stripes disappeared.The muscle nuclear wrin-kled or increased.Some formed homogeneous material without the structure.Conclusion In conclusion,the femoral greater trochanter region iliotibial tract and the jun-ction can be showed directly, accuratly, and clearly by high-frequency ultrasound.The thickness of ITT could be measured in a standard section by bone landmark. Theultrasound standard of the femoral greater trochanter region iliotibial tract in healthypeople could be established.The ultrasound diagnostic criteria of normal ITT will bebenefit of the further study related to ITT. Dynamic sonography is able to display realtime images of sudden abnormal jerky movement of the iliotibial tract and the jun-ction of gluteus maximus muscle over the greater trochanter,which would causes asnap during hip motion,and it can be used for an initial study to evaluate iliotibialtract contracture. As a result, ultrasound is worthy in clinical iliotibial tract contra-cture.