Rotator cuff disease (i.e., rotator cuff tendinopathy or tear) is a common cause of shoulder pain in persons with chronic spinal cord injury (SCI). It usually resolves with non-operative treatments such as pharmacological agents and physical therapy; however, when this fails, rotator cuff surgery may be the only option. Corticosteroid injections are another alternative to provide temporary relief, but can over time accelerate degeneration of the tendon and lead to further damage. Autologous adipose tissue injection has recently emerged as a promising new treatment for joint pain and soft tissue injury. Adipose can be used to provide cushioning and filling of structural defects and has been shown to have an abundance of bioactive elements and regenerative perivascular cells (pericytes). The purpose of this study is to explore the efficacy of autologous, micro-fragmented adipose tissue (Lipogems®) injection under ultrasound guidance for chronic shoulder pain in persons with SCI compared with the standard-of-care, corticosteroid injection.

This is randomized controlled trial to determine the efficacy of autologous, micro-fragmented adipose tissue (MFAT) injection under ultrasound guidance for chronic, nonresponsive shoulder pain due to rotator cuff disease (i.e., rotator cuff tendinopathy) in persons with spinal cord injury (SCI). The control for this study, to which MFAT will be compared, is corticosteroid injection into the subacromial space. Twenty-four (24) persons with SCI who have chronic shoulder pain for longer than 6 months in spite of completing conservative treatment and who are diagnosed with rotator cuff disease on examination will be recruited.

MFAT Group: Micro-fragmented adipose tissue will be obtained by using a minimal manipulation technique in a closed system (Lipogems®), without the addition of enzymes or any additives. The final product will consist of micronized fat tissue yielding fat clusters with preserved vascular stroma of about 500 microns with intact stromal vascular niches and harboring regenerative cellular elements. Approximately 6 mL of micro-fragmented adipose will be injected into the tendon with a 22-gauge needle under continuous ultrasound guidance. No other biological or pharmacological agents will be used in combination with the micro-fragmented adipose.

Corticosteroid Group: In the corticosteroid group, participants will receive a corticosteroid injection (BMS, Kenacort-A 40 mg [triamcinolone acetonide]) into the subacromial space under direct ultrasound guidance by means of a 5-mL syringe with a 22-guage needle.

Both Groups: After 24 hours, participants will be given a standardized stretching protocol to follow for 4 weeks followed by a formal strengthening program. Participants will be followed for adverse events and changes in shoulder pain intensity on an 11-point numerical rating scale (NRS; 0-10, with anchors "no pain" and "pain as bad as you can imagine"); the Wheelchair User's Shoulder Pain Index (WUSPI; 15-item disease-specific functional measure of shoulder pain in persons with SCI); the PROMIS Physical Functioning short form; the Brief Pain Inventory interference items (BPI-I7; a subscale of 7 items measuring interference with general activity, sleep, mood, relationships, etc.); and a 5-point subject global impression of change (SGIC) scale. Subjects will be examined at 1 month, 2 months, 3 months, and 6 months after the treatment. In addition to subjective outcome measures, quantitative ultrasounds will be conducted at baseline, 1 month, 2 months, 3 months, and 6 months post-treatment.

Inclusion Criteria:

• Men and women, 18 to 70 years of age, inclusive
• Neurological impairment secondary to a spinal cord injury or disorder that occurred at least twelve (12) months prior to the Screening Visit and the level of the injury is between C6 and L5, inclusive
• Non-ambulatory except for exercise purposes and uses a manual or power wheelchair as his/her primary means of mobility (> 40 hours/week)
• Currently has chronic shoulder pain due to rotator cuff disease in spite of at least 6 months of conservative treatment
• Average shoulder pain intensity during the week leading up to the Screening Visit is at least 4 out of 10 on an 11-point numerical rating scale (NRS; 0, no pain; 10, maximum pain imaginable).
• Rotator cuff disease will be defined as pain over the anterior shoulder, with direct palpation and pain at the shoulder with provocative tests for rotator cuff disease that is confirmed by tendinopathic changes on ultrasound imaging.

Exclusion Criteria:

• Report prior MFAT treatment
• Have a history of systemic disorders, such as diabetes or rheumatoid arthritis
• Have a contra-indication to the procedure, such as infection, coagulopathy, or currently taking anti-coagulant
• Report having a glucocorticoid injection in the past 4 weeks
• Are pregnant
• Have any medical condition, including psychiatric disease, which would interfere with the interpretation of the study results or the conduct of the study

The assessor will be blinded to treatment group when analyzing data for publication.