Association Between the Elasticity of Hip Muscles and the Hip Migration Index in Cerebral Palsy

Abstract

Objectives-Cerebral palsy (CP) increases the risk of hip displacement during childhood. Abnormal hip muscle forces have been proposed as the predisposing factors. In CP, the amount of hip displacement is commonly evaluated by the Reimers hip migration index (MI) on an anteroposterior pelvic radiograph. To the best of our knowledge, the association between the elasticity of hip muscles measured by shear wave elastography and the MI has not been studied yet. Herein, we aimed to analyze the correlation between the elasticity of hip muscles and the MI.Methods-Bilateral hips of 25 children with spastic CP were included prospectively in this study. Anteroposterior pelvic radiographs were used to measure the MI. Shear wave elastography was performed to evaluate the elasticity of muscles. The correlation between the MI and the elasticity of hip flexor and adductor muscle groups was assessed. Also, the association between the elasticity of agonist/antagonist muscles was analyzed.Results-The MI showed fair to good correlations with hip flexors and adductors for both readers (0.71 ≥ r ≥ 0.52). The mean MIs of the patients AE SDs were 22.64% AE 7.79% for reader 1 and 21.55% AE 8.83% for reader 2. The elasticity of agonist/antagonist muscle groups showed little/no to a weak correlation for both readers (0.32 ≥ r ≥ -0.07).Conclusions-Although, hip flexor and adductor muscle elasticity showed a correlation with MI, it seems very hard to say that increased elasticity of hip flexor and adductor muscles causes hip dislocation.

Is there a correlation between the femoral anteversion angle and the elasticity of the hip muscles in cases of intoeing gait due to increased femoral anteversion angle?

“…Analan et al . found a weak correlation between the MI and other hip muscles ( 17 ) . In the present study, we identified a weak correlation between the FAA and other hip muscles.…”

Muscle Ultrasonographic Elastography in Children: Review of the Current Knowledge and Application

“…To test the hypothesis that hyperactivity and spasticity of the hip abductors and flexors result in the hip displacement in CP, Doruk Analan et al analysed the correlation between the Reimers hip migration index and the elasticity of the mentioned muscles on SWE. No significant correlation was found [37].…”

Evaluation of iliopsoas tendon using shear wave elastography after open reduction surgery for developmental dysplasia of hip

“…Many soft tissues such as tendons, muscles, and fascia in the human body have begun to be examined with this technique. [ 13 , 25 , 26 ] Many studies have examined structural changes in skeletal muscle using the elastography technique, particularly hip muscles in patients with CP. Vola et al[ 14 ] found that the soleus muscle was more rigid in patients with CP.…”

“…Elastography, on the other hand, is a low cost, fast, non-invasive US-based application that allows quantitative evaluation of the properties of soft tissues, such as stiffness and flexibility. [9][10][11][12][13] Although there are several different elastography techniques, the most commonly used techniques sonoelastography, real-time elastography and shear wave, also known as realtime elastography. Shear wave elastography (SWE) is an objective method that quantitatively interprets muscle and tendon structures independently from the radiologist.…”