Procedures and interventions
STERILE
For the ACP/STR preparation, we used a double lumen syringe (Arthrex ACP™ Double Syringe, Arthrex Inc. Naples, FL, USA) and 15 ml blood were taken from the patients followed by 5 min of centrifugation (1500 turns/min, Rotofix 32A, Hettich). The obtained plasm a was immediately mixed with the collagen scaffold Vergenix STR, an engineered human collagen extracted from tobacco plants (STR, CollPlant Ltd., Ness-Ziona, Israel) and subsequently applied into the subacromial space [The CSA group received 10 ml bupivacaine (0, 5%) and 2 ml of dexamethasone.The injections for both groups were performed under sterile conditions, as well as ultrasound guided, from the lateral aspect of the proximal humerus into the subacromial space.All injections were performed by the same clinician. After injection, all patients underwent a standard rehabilitation protocol by the same physical therapist.In the first two weeks, the patients received manual therapy for the shoulder including cervical spine, ergotherapy and manual lymphatic drainage as well as exercises in the pain-free range of motion. In the further 3–6 weeks, the therapy was continued with arm muscle stimulation/building and extension of ROM against resistance.