Post op shoulders with shearwave assessment

Abstract

Introduction Little is known about the morphology of healing rotator cuff after surgical repair. Shear wave elastography ultrasound (SWEUS) is a relatively new technique that evaluates tissue elasticity by applying an acoustic radiation force impulse (ARFI). The aim of this study was to evaluate in a temporal fashion the stiffness of the repaired supraspinatus tendon post arthroscopic repair using shear wave elastography ultrasound imaging (SWEUS). Methods An intra-inter reliability trial showed that SWEUS (Siemens Acuson S2000 HELIX; Siemens Medical Solutions, Mountain View, California) was very reliable at assessing the supraspinatus tendon (r > 0.9). The mean (± SEM) stiffness of normal human supraspinatus tendon was 9.96 ± 0.02 m/s. To evaluate the healing tendon fifty participants (30 males and 20 females) were enrolled one week post arthroscopic rotator cuff repair. The mean age was 57 (range 24-85) years old. A grey-scale ultrasound image of the supraspinatus tendon was recorded. Shearwave elastography ultrasound was applied and a sample box positioned within the supraspinatus tendon to assess the post operative supraspinatus tendon, in three specific areas, using a standardized protocol by a single sonographer. In addition, the humeral head (positive control) and the deltoid muscle (negative control) were evaluated on each occasion. Each sample recorded the velocity(m/s), depth of the sampling box (cm) and elasticity (kPa). These assessments were repeated at 8 days, 6 weeks, 12 weeks and 6 months post operative rotator cuff repair. Results Of 50 patients, 3 re-tore their tendons at 6 weeks and 1 re-tore at 12 weeks. Shearwave values of the positive (9.9 m/s ± 0.03) and negative (3.7 m/s ± 0.15) control regions were unchanged throughout the study. The lateral tendon in the anatomical footprint (lateral region) and the tendon medial to the footprint increased in stiffness in an exponential fashion over 6 months (p Conclusion The tendon stiffness as assessed by shearwave elastography increased as the supraspinatus tendon healed in a consistent uniform fashion post rotator cuff repair at the lateral insertion and the tendon medial to the insertion. At six months the average stiffness was 80% of normal supraspinatus tendon.