Partial thickness rotator cuff tears include articular side tear, bursal side tear, intratendinous tear, and complex type tear. The method of treatment for partial thickness rotator cuff tear may vary depending on the cause and location of the tear and the clinical symptoms of the patient. Initiate conservative treatments such as relaxation, lifestyle changes, and nonsteroidal anti-inflammatory drugs, which can be expected to reduce pain and reduce pain. Steroid injections can also be tried. Surgical treatment can be considered when clinical symptoms worsen or do not improve after adequate conservative treatment. Steroid injection therapy is widely used in injection therapy and its effect is known to be excellent. However, there have been reports of cases of collagen necrosis after steroid injection in the area of calcaneal tendon in rabbits, as well as reports on the association between steroid injection and rupture of the tendon. Recently, there has been research showing that steroids not only inhibit cell viability and collagen production, but also inhibit the proliferation of tenocytes. In comparison, atelocollagen injections have fewer reports of side effects. Tendons are composed of tenocytes, which are specialized mesenchyme-dervied cells in an extratracellualr matrix. The extracellular matrix is composed of more than 95% of type I collagen, and is composed of type III and V collagen, proteoglycan, elastin, and fibronectin. Collagen, the main component of the extracellular matrix, transmits power, dissipates energy, and supports soft tissues. Atelocollagen is made by removing the terminal telopeptide with a proteolytic enzyme, which lowers immunogenicity, and has many advantages that can lower side effects by improving biocompatibility and interaction between collagen and cells. If the healing reaction is difficult to activate due to lack of blood circulation such as cartilage, ligaments and tendons, it can be used as a method to increase the possibility of tissue healing. Currently, studies on the effect of collagen injection in the ankle and knee disease have been reported, but there is a lack of reports on collagen injection therapy in shoulder disease. Atelocollagen injection therapy has been performed to prevent the progression of rotator cuff tears. It will be confirmed and published in the journal. We will report on the effect of atelocollagen injections on rotator cuff tears. Atelocollagen injection therapy has been proven to be effective in reducing the tear size in patients with rotator cuff tears, and could be one of the treatment methods for partial rotator cuff tears. Currently, one to three injections of atelocollagen are tried depending on the size and recovery of rotator cuff tear. However, the relationship between the reduction of rotator cuff tear size and the recovery of shoulder function after atelocollagen injection therapy is insufficient. The purpose of this study is to analyze the degree of rotator cuff tear recovery after multiple atelocollagen injections in patients with partial thickness rotator cuff tears. In addition, we will analyze the relationship between the recovery of rotator cuff tear and the improvement of shoulder function by comparing the patients whose rotator cuff tear have recovered and those whose rotator cuff tear maintain or worsen.

Cohort/Group Label

Group of patients with multiple atelocollagen injection in partial thickness rotator cuff tear

Cohort/Group Description

Study design: case series study
The purpose of this study and the research method are explained in detail. A screening test will be conducted on those who have agreed in writing, and a person who meets the inclusion criteria will be selected. The study's plan will be detailed in the subject description and will be conducted only with patients who have received sufficient explanation and agreed. From the time of writing the research agreement, the patients will participate in the research. Patients who agreed to the study received two atelocollagen injections every three months. Atelocollagen injection treatment at 3 month intervals is an ongoing treatment protocol. During atelocollagen injection, the patient sterilizes the anterior and upper segments of the joint and humerus while keeping the arm in the crass position while sitting on a chair. During atelocollagen injection, the patient is sitting in a chair with patient's arm in the crass position, and the doctor sterilizes the anterior and upper part of the glenohumeral joint. Using a high-resolution transducer (12 MHz linear array), we would confirm that the needle is located at the rupture site of the rotator cuff and inject 1 ml of atelocollagen. The same method of atelocollagen injection is administered once more three months after the first atelocollagen injection. All patients who participated in the study would visit outpatient clinic at 6 weeks, 3months, 6months, and 12 months after injection. The doctor will check patient's range of motion, visual analog scale (VAS), the American Shoulder and Elbow Surgeons (ASES) score, Constant score, and Korean shoulder score at every visit of outpatient clinic. During the follow-up periods, pain control will be performed using NSAIDs. We would check the change of rotator cuff tear by ultrasound and magnetic resonance imaging. During the outpatient follow-up period, the patient is investigated for complications due to the ingjection or drug.

Not collect nor Archive

1)	Adults over 30 and under 70
2)	Partial thickness rotator cuff tear diagnosed by imaging test (ultrasound or MRI)

Study design: case series study
The purpose of this study and the research method are explained in detail. A screening test will be conducted on those who have agreed in writing, and a person who meets the inclusion criteria will be selected. The study's plan will be detailed in the subject description and will be conducted only with patients who have received sufficient explanation and agreed. From the time of writing the research agreement, the patients will participate in the research. Patients who agreed to the study received two atelocollagen injections every three months. Atelocollagen injection treatment at 3 month intervals is an ongoing treatment protocol. During atelocollagen injection, the patient sterilizes the anterior and upper segments of the joint and humerus while keeping the arm in the crass position while sitting on a chair. During atelocollagen injection, the patient is sitting in a chair with patient's arm in the crass position, and the doctor sterilizes the anterior and upper part of the glenohumeral joint. Using a high-resolution transducer (12 MHz linear array), we would confirm that the needle is located at the rupture site of the rotator cuff and inject 1 ml of atelocollagen. The same method of atelocollagen injection is administered once more three months after the first atelocollagen injection. All patients who participated in the study would visit outpatient clinic at 6 weeks, 3months, 6months, and 12 months after injection. The doctor will check patient's range of motion, visual analog scale (VAS), the American Shoulder and Elbow Surgeons (ASES) score, Constant score, and Korean shoulder score at every visit of outpatient clinic. During the follow-up periods, pain control will be performed using NSAIDs. We would check the change of rotator cuff tear by ultrasound and magnetic resonance imaging. During the outpatient follow-up period, the patient is investigated for complications due to the ingjection or drug.

Gender

Age

Description

Inclusion Criteria
1)	Adults over 30 and under 70
2)	Partial thickness rotator cuff tear diagnosed by imaging test (ultrasound or MRI)
3)	Patients who have been treated for more than 3 months by medication or physical therapy but have not improved
4)	If the concomitant medication continues to be administered during the trial, patients who have confirmed the correct prescription drug being taken within at least one week and agreed to maintain a constant amount as before injection during the study
5)	patients who understand the study, agree to participate in the study, and have their own written consent

Exclusion Criteria 
1)	Patients with previous history of injection therapy within 6 weeks
2)	Patients with Adhesive capsulitis
3)	Full thickness rotator cuff tears diagnosed by MRI or ultrasound
4)	Patients with a history of uncontrolled diabetes, infectious arthritis, rheumatoid arthritis, tumors, fractures, degenerative arthritis
5)	Patients who refuse injection
6)	Patients who want surgical treatment
7)	Patients with hypersensitivity to collagen
8)	Pregnant or lactating or planning to become pregnant
9)	Patients expected to have complications because of anticoagulants therapy
10)	Patients sensitive to pig protein
11)	Patients with a history of radiotherapy and chemotherapy within the past 2 years (except when it is determined that collagen can be administered as judged by a clinician)
12)	Patients or family members with autoimmune disease in progress or with past military service
13)	Patients who are sensitive to implants 
14)	Any clinically significant health abnormalities that can affect the completion of the study
15)	Patients deemed inappropriate for this study by the judgment of doctor such as mental illness

imaging study : shoulder MRI

6 months after first injection

shoulder sonography

6 weeks, 3 months, 12 months after first injection

shoulder functional score (ASES score, Constant score, KSES score)

6 weeks, 3 months, 6months, 12 months after first injection

shoulder range of motion

6 weeks, 3 months, 6months, 12 months after first injection

Pain VAS score

6 weeks, 3 months, 6months, 12 months after first injection