Elasticity of the coracohumeral ligament in patients with frozen shoulder following rotator interval injection: a case series

Abstract

Aim of the study: To evaluate changes in the elasticity of the coracohumeral ligament in patients with adhesive capsulitis of the shoulder treated with ultrasound-guided rotator interval injections. Methods: Shear wave elastography was used to evaluate elasticity of the coracohumeral ligament in symptomatic and asymptomatic shoulders in the shoulder-neutral position and 30° external rotation. A total of 24 shoulders were assessed. Symptomatic shoulders were treated with targeted steroid injection via the rotator interval and manipulation under local anaesthetic block. Follow-up assessment of the elasticity of the coracohumeral ligament was obtained at 10 weeks post-injection. Results: In all subjects, the coracohumeral ligament elastic modulus was larger at 30° external rotation than in the neutral position. In patients with adhesive capsulitis, the coracohumeral ligament thickness and elastic modulus was significantly greater in the symptomatic shoulder in the neutral position and 30° ER. Treated patients had an excellent response with improved Oxford Shoulder Score and reduced visual analogue scale pain scores. Median Oxford Shoulder Score was 13.5 pre-injection and 34 at 10 weeks postinjection. Median visual analogue scale pain scores measured 8.5 pre-injection, 3.5 at 1 day, 2 at 1 week, and 2.5 at 10 weeks. Improved Oxford Shoulder Score and visual analogue scale pain score was associated with a trend to normalisation of the elastic modus of the coracohumeral ligament. Conclusion: In patients with adhesive capsulitis of the shoulder, shear wave elastography demonstrated the coracohumeral ligament is stiffer in the symptomatic shoulder than in the unaffected shoulder. Treatment with the ultrasound-guided rotator interval injection is associated with improved Oxford Shoulder Score, reduced visual analogue scale pain scores, and reduced stiffness in the coracohumeral ligament.

Shear Wave Elastography of the Coracohumeral Ligament With Frozen Shoulder in Different Stages

“…Second, due to the limitation of the maximum Er of frozen shoulder in stage II, some patients were unable to achieve an Er of 30°; therefore, all the subjects in this study were limited to an Er of 10°, which is different from the Er of 30° or the maximum Er of the shoulder joint in previous studies, 16 which will also lead to differences in the shear wave value of CHL. Third, the depth of the region of interest measured by SWE was different from that previously reported 14‐16 . SWE measurements in regions of interest of different depths in the same organization can lead to different measurements 26 .…”

“…In our study, the measured value of the SWE of the CHL was smaller than that in previous studies, which may be due to several reasons. First, the machines (LOGIQ E9, GE Healthcare) used in this study were different from those used (Supersonic Imagine, Aix‐en‐Provence, France) by McKean et al 15 and Wu et al 14 in their studies of the SWE of the CHL, which may be the main reason why the SWE measured in this study was quite different from that in previous studies 24–29 . This difference may be due to the patent protections of each system and tracking wave technology, so care should be taken in comparing the SWE values of machines from different suppliers.…”

“…First, the study was not divided into age groups. Some studies have reported that the SWE of the CHL in healthy people could also increase with age, 15 so future studies should be further studied according to the age group. Second, the staging of frozen shoulder was not confirmed by arthroscopy and pathology.…”

“…The criteria for a diagnosis of frozen shoulder are as follows: 1) shoulder pain, 2) limited ROM of the shoulder joint, 3) ultrasonic examination of the CHL revealing a thickness ≥4 mm 15 . The patient exclusion criteria are as follows: 1) fracture and dislocation of the shoulder joint, 2) rotator cuff injury and tendon disease, 3) tuberculosis, rheumatoid, systemic infection and blood system diseases, and 4) incomplete inspection data.…”

“…In recent years, SWE has been widely used in the diagnosis of tendon, muscle, and ligament diseases. Some studies have shown that ligament thickening and stiffness increase in frozen shoulder patients due to CHL fibrosis; therefore, the SWE of the CHL is increased in patients with frozen shoulder detected by SWE 14,15 . However, it is not clear whether the SWE of the CHL on the affected side is larger than that on the healthy side in all stages of frozen shoulder, whether the SWE of the CHL on the affected shoulder is the same in all stages, or whether there is a correlation between the SWE of the CHL and the visual analogue scale (VAS) score and ROM in each stage of the affected shoulder.…”