Determination of the reference range for semi-quantified elasticity of healthy supraspinatus muscles using real-time tissue elastography and its clinical use in patients after rotator cuff repair.

BACKGROUND: The quantitative assessment of healthy supraspinatus muscle elasticity may provide clinically useful preliminary information after rotator cuff repairs. We aimed to determine the reference range for supraspinatus muscle semi-quantified elasticity and describe how it can be used clinically after rotator cuff repair. METHODS: The elasticity of healthy bilateral supraspinatus muscles in 43 participants aged between 24 and 75 years (categorized into two subgroups: <50 and ≥ 50 years) was measured as a strain ratio at 0° and 60° of shoulder abduction using real-time tissue elastography. The reference and modified reference ranges calculated by excluding outliers for elasticity were determined using normal distribution methods for logarithmically transformed data. The modified reference range was applied to eight cases of rotator cuff repair. FINDINGS: Strain ratios under and over 50 years of age were 1.63 vs. 2.21 at 0° of shoulder abduction (P = 0.028) and 0.92 vs. 1.29 at 60° of shoulder abduction (P = 0.002), respectively. Modified reference ranges for under and over 50 years of age were 0.72-4.17 and 0.98-4.50 at 0° of shoulder abduction and 0.38-1.95 and 0.56-2.76 at 60° of shoulder abduction, respectively. Among eight cases, two showed strain ratios above the reference range at 1 month postoperatively, and rehabilitation protocols were adjusted. INTERPRETATION: A strain ratio above the reference range, especially above the upper limit at 0° of shoulder abduction, may indicate increased passive stiffness of the musculotendinous unit. Clinically, the reference range has the potential to be used as a baseline after rotator cuff repairs.

Providing safe and effective rehabilitation by assessing supraspinatus muscle elasticity using ultrasound real-time tissue elastography after rotator cuff repair: A case series.

INTRODUCTION: Although surgical techniques have advanced to avoid a postoperative re-tear after rotator cuff surgery, it remains unclear how to directly evaluate the risk of a re-tear. OBJECTIVE: To describe how muscle elasticity with real-time tissue elastography could be used to avoid re-tear in individual cases after rotator cuff repair. CASE DESCRIPTION: This case series included four patients, two per tear size (small and large/massive), with contrasting changes in muscle elasticity of the supraspinatus muscle. All patients underwent primary arthroscopic or open rotator cuff repair. The elasticity of the supraspinatus muscle was evaluated at relaxed and elongated positions of 0° and 60° shoulder abduction angles, respectively. The change in muscle elasticity at 1 month after surgery was characteristically different, and we predicted that a greater elasticity in the elongated position indicated a higher risk of re-tear. The cases with high risk underwent careful rehabilitation to avoid re-tear, and no re-tears were recorded in this report. CONCLUSION: Our findings suggested that evaluation of muscle elasticity using real-time tissue elastography, which provides an indication of the risk of re-tear, in the clinical setting might be useful for therapists, who could adjust the intensity of rehabilitation, and for patients.

Introduction of the Purdue Pegboard Test for fine assessment of severity of cervical myelopathy before and after surgery.

[Purpose] To evaluate the severity of symptoms before and after cervical myelopathy surgery using the Simple Test for Evaluating hand Function. Because a test ceiling effect was observed in patients with less severe forms of myelopathy, we investigated the correlation between and accuracy of several different tests in order to clarify the usefulness of the Purdue Pegboard Test for evaluation of one or both hands. [Participants and Methods] Thirty-four patients (6 females and 28 males; mean age, 64.5 years) were examined, and scores were determined for each of the following tests: Purdue Pegboard Test; Simple Test for Evaluating hand Function; Japanese Orthopedic Association assessment; and Disabilities of the Arm, Shoulder, and Hand assessment. Correlations between scores of different tests were then determined. The cut-off values used for the Purdue Pegboard Test and the Simple Test for Evaluating hand Function were determined using the area under the receiver operating characteristic curve to assess the use of chopsticks. [Results] The Purdue Pegboard Test assembly task correlated moderately with the Japanese Orthopedic Association and Disabilities of the Arm, Shoulder, and Hand scores. In the receiver operating characteristic curve analyses, the Purdue Pegboard Test cut-off value was 11 and the Simple Test for Evaluating hand Function cut-off value was 90. [Conclusion] The Purdue Pegboard Test is useful for evaluating manual dexterity and coordination in both hands in patients with cervical myelopathy.