Ultrasound-Guided Treatments for Shoulder Pain in Wheelchair Users With Spinal Cord Injury

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.