Increased Reliability of Quantitative Ultrasound Measures of the Supraspinatus Tendon Using Multiple Image Analysts and Analysis Runs

The Correlation of Quantitative Ultrasound Measures and Supraspinatus Tendon Quality: A Pilot Study

Background:

The objective of this study was to determine the feasibility of assessing tendon quality as quantified by histology through changes in quantitative ultrasound measures.

Methods:

Eight cadaveric shoulders (four with a small supraspinatus tendon tear) were examined using conventional B-mode ultrasound in the transverse plane by internally rotating and hyperextending the humerus. Quantitative ultrasound measures (skewness, kurtosis, variance, and echogenicity) were calculated based on the grayscale distribution of the ultrasound image taken of the supraspinatus tendon near the insertion site. The specimens were then dissected to the supraspinatus tendon where tendon biopsies were taken near the insertion site, mid-substance, and myotendinous junction. Through histology, tendon quality was evaluated based on collagen fiber organization, fatty infiltration, nuclei shape, and cellularity. Correlations between quantitative ultrasound measures and histological grades of tendon quality were determined through Pearson or Spearman's rho correlations.

Results:

A total of three significant correlations between quantitative ultrasound measures and histological parameters of tendon quality were found. Significant correlations between kurtosis and cellularity at the insertion site (r = 0.724) (P < 0.05) as well as variance and fatty infiltration at the myotendinous junction (ρ = −0.843) (P < 0.05) and for the whole tendon (ρ = −0.826) (P < 0.05) were found.

Conclusion:

The results show the potential for quantitative ultrasound measures to assess factors of tendon quality that can only be determined through histology. With further development of the methodology that utilizes quantitative ultrasound measures, clinicians might be able to evaluate the tendon quality noninvasively in future.

Proposing a Minimal Data Set of Musculoskeletal Ultrasound Imaging Biomarkers to Inform Clinical Practice: An Analysis Founded on the Achilles Tendon

Tendon integrity can be described using a wide range of biomarkers via specialized analysis software for images recorded by musculoskeletal ultrasonography. This study proposes a minimal biomarker data set to characterize Achilles tendon ultrasound images and to differentiate between symptomatic and asymptomatic Achilles tendon images. Forty-one individuals with unilateral Achilles tendinopathy and 35 healthy controls had their Achilles tendon images recorded bilaterally by ultrasonography in the longitudinal and transverse planes. A set of 22 biomarkers, organized around three dimensions (geometric, composition and texture), were computed in each plane. A symmetry index, reflecting relative side differences, was compared between groups and analyzed through principal component analysis to isolate biomarkers that best explained data variance. A specific minimal data set was identified by linear regression in the longitudinal (mean thickness, echogenicity, variance and homogeneity at 90°) and transverse (mean thickness, echogenicity and mean homogeneity) planes to characterize and differentiate Achilles tendon integrity.

Effects of Home Exercises on Shoulder Pain and Pathology in Chronic Spinal Cord Injury: A Randomized Controlled Trial

OBJECTIVE

The aims of this study were to replicate findings that a home exercise program intervention improved shoulder pain and function and to assess changes in supraspinatus tendon pathology associated with the home exercise program in persons with chronic spinal cord injury.

DESIGN

The study is a single-blind randomized controlled trial. Individuals with spinal cord injury of at least 1 yr and chronic shoulder pain of moderate or greater average intensity were enrolled. Participants were randomized to a 12-wk home exercise program consisting of strengthening and stretching exercises or to an education-only control group, with immediate postintervention and 4-wk postintervention (16 wks) follow-ups. The main outcome measures were self-report measures of shoulder pain and impairment, the Physical Examination of the Shoulder Scale, quantitative ultrasound metrics of the supraspinatus tendon, and the Ultrasound Shoulder Pathology Rating Scale.

RESULTS

Thirty-two participants were randomized to home exercise program or education-only control condition. The mean ± SD age was 44.8 ± 12.5; 81.3% were male; 65.6% had motor complete paraplegia. Using a per-protocol, within-group analysis method, significant differences were observed between baseline and postintervention for the home exercise program group for the least pain intensity (P = 0.02), number of days with shoulder pain (P = 0.042), Physical Examination of the Shoulder Scale scores (dominant side, P = 0.036; nondominant side, P = 0.008), the Disabilities of the Arm, Shoulder, and Hand (P = 0.028), and the Patient Global Impression of Change (P = 0.015). The education-only control condition group demonstrated significant changes in average unpleasantness of shoulder pain after the intervention period (P = 0.049). Comparisons in changes from baseline between groups showed that the home exercise program group had greater improvements in nondominant-side Physical Examination of the Shoulder Scale scores and global impression of change, whereas the education-only control condition group had greater improvements in depressive symptoms.For quantitative ultrasound measures, no significant changes were found with within-group analyses for the home exercise program group, although the education-only control condition group demonstrated a decrease in tendon width in the nondominant-side supraspinatus tendon (P = 0.036). Comparison of changes between groups suggests that the education-only control condition group had a greater increase in dominant shoulder supraspinatus tendon ultrasound contrast at the end of the study.

CONCLUSIONS

Changes in several measures of shoulder pain and function occurred after the home exercise program intervention, although the magnitude of changes was only significantly greater than those of the education-only control condition group for two measures. Significant changes in supraspinatus pathology were not detected with quantitative ultrasound metrics.