This study is aprospective cohort study on the outcome of a combination of bone marrow stimulation and modified suture bridge in the arthroscopic treatment of small and medium rotator cuff tear. The patients with small to medium rotator cuff injuries (less than 3cm in diameter) requiring arthroscopic surgery were collected. The patients were followed up before and 6 weeks, 3 months, 6 months and 12 months after surgery, including pain, functional score, joint range of motion, MRI and CT findings, complications and other quantitative and qualitative indicators. The self-control and intra group analysis were performed to evaluate the treatment effect; and the correlation analysis was performed on the treatment results To determine the important factors affecting the therapeutic effect.

Inclusion Criteria:

• Arthroscopy confirmed small to medium rotator cuff injury
• The data of preoperative functional examination were complete
• Unilateral rotator cuff injury
• Clinical follow-up can be completed

Exclusion Criteria:

• Anterior superior rotator cuff injury with simple subscapular injury or combined subscapular injury
• Previous shoulder surgery (incision or arthroscopy)
• Combined with diseases of other parts of the same limb
• Combined with Bankart injury, acromioclavicular joint disease, greater tuberosity fracture, glenoid fracture and so on
• Bilateral onset
• Unable or unwilling to receive clinical follow-up

According to the inclusion and exclusion criteria, 40 patients with small to middle rotator cuff injury treated by this technique（Greenhouse tec） in our hospital from September 2020 to December 2021 were included.