Clinical outcome of ultrasound-guided atelocollagen injection for patients with partial rotator cuff tear in an outpatient clinic: a preliminary study

Abstract

Background: Atelocollagen has been studied for restoration of rotator cuff tendon. In this study, we attempted to evaluate the clinical outcome of ultrasound-guided atelocollagen injection in an outpatient clinic for patients with partial rotator cuff tear.Methods: We recruited 42 outpatients who visited our hospital from May 2019 to September 2019. Atelocollagen injection was performed in patients with partial rotator cuff tear diagnosed by magnetic resonance imaging and ultrasound. American Shoulder and Elbow Surgeons (ASES), Constant, Korean Shoulder Score (KSS) and Simple Shoulder Test (SST) scores, and range of motion were assessed before injection and after two months. Statistically, we analyzed the clinical results using the Wilcoxon signed rank test.Results: Finally, 15 patients were enrolled for analysis. There was no significant difference between pre- and post-injection in terms of range of motion, ASES (57.0 vs. 60.4), Constant (56.4 vs.58.9), KSS (64.6 vs.68.5), and pain-visual analog scale (4.2 vs.3.7), except function-visual analog scale (F-VAS; 6.3 vs.7.1) and SST (6.6 vs.6.9). A significant difference was found in SST (P=0.046) and F-VAS (P=0.009). According to the ultrasound results at 2 months, we found hyperechoic materials in three of seven patients. The most common complication of atelocollagen injection was post-injection pain (53%, 8/15).Conclusions: Ultrasound-guided atelocollagen injection for partial rotator cuff tear showed no significant change in terms of clinical outcomes, except for F-vas and SST score. Tendon regeneration was not clear due to the remnants of atelocollagen present at 2-month follow-up ultrasound. There seems to be alarming post-injection pain for 2 to 3 days in the patients who received atelocollagen injection in an outpatient clinic.

Effects of Arthroscopic Atelocollagen Insertion in High-Grade Partial Articular Supraspinatus Tendon Avulsion Lesions: A Retrospective Cohort Study With Propensity Score Matching

“…Gel-type atelocollagen is also used for ultrasonography-guided injection for partial rotator cuff tears or arthroscopic injection to the repaired rotator cuff tendon. For gel-type atelocollagen delivery, the injection is performed directly to the tear site using ultrasound in the outpatient clinics 2,15 or intraoperatively after rotator cuff repair. 12,14 Table 3 summarizes the findings of 2 level 1 randomized controlled trials that reported on clinical applications of atelocollagen.…”

“…There are studies that have analyzed radiological results after ultrasound-guided injection with follow-up ultrasound or MRI. 2 , 15 In a study by Chae et al, 2 rotator cuff integrity was measured via an ultrasound performed 2 months after surgery, while muscle volume, fatty infiltration, and retear were measured at 6 months after surgery using MRI. Clear differences in tendon integrity from preinjection to postinjection were not found.…”

“…Although the retear rate, which is considered the most important finding on MRI, decreased according to Jeong et al 12 and Kim et al, 15 other studies found no significant statistical differences in the healing rate or regeneration. 2 , 14 Most studies reported improved clinical outcomes, especially in the VAS pain score. 2 , 12 - 15 In the present study, intraoperative addition of atelocollagen did not improve outcome scores.…”

“… 2 , 14 Most studies reported improved clinical outcomes, especially in the VAS pain score. 2 , 12 - 15 In the present study, intraoperative addition of atelocollagen did not improve outcome scores. However, there was slighter greater ROM.…”

In Situ-Forming Fibrin Gel Encapsulation of MSC-Exosomes for Partial-Thickness Rotator Cuff Tears in a Rabbit Model

“…Second, the open view during surgery in our study facilitated the accurate injection of ASC-Exos/fibrin into the defect site, which could be challenging in the clinic. Nevertheless, with ultrasound guidance 26,27 , it is feasible to perform accurate injections into the defect site of the cuff tendon. Third, clinical parameters (e.g., pain, activity level, gait) were not assessed.…”