Abstract
BACKGROUND: Partial-thickness rotator cuff tears (PTRCTs) is not uncommon, and various nonsurgical injection therapy for PTRCTs emerged. Platelet-rich plasma (PRP) and hyaluronic acid (HA) injection were proposed for treating PTRCTs; however, the relation of dose among injectates was still lacking. METHODS: This was a prospective, nonrandomized, comparative study. The aim of the study was to compare the effects of ultrasound-guided single PRP injection with three doses of HA injection, combination of postinjection rehabilitation, for treating PTRCTs. Subjects received either ultrasound-guided PRP injection and rehabilitation exercise, or ultrasound-guided subacromial HA injection and rehabilitation exercise. Shoulder Pain and Disability Index (SPADI), range of motion (ROM), pain visual analog scale (VAS), and Constant-Murley Shoulder Score (CMSS) were recorded before injection, and at 1 and 3 months after injection. RESULTS: Forty-eight patients were enrolled. They received either ultrasound-guided single PRP (n = 24) intralesional and peritendinous injection or three doses of HA (n = 24) subacromial injection plus rehabilitation exercise. In the PRP group, SPADI scores, VAS scores, CMSS significantly improved at 1-month and 3-month follow up; flexion and abduction ROM significantly increased at 3-month follow up. In the HA group, SPADI scores, VAS during overhead activities, VAS night pain, and CMSS significantly improved in the first and third months; flexion and active abduction ROM significantly increased in the third month. The PRP group revealed significantly better passive abduction ROM and CMSS at third month than HA group. CONCLUSION: Ultrasound-guided single PRP injection exhibited comparable benefit to three doses of HA injection in patients with PTRCTs short-termly, with an extended effect regarding passive shoulder abduction ROM and CMSS.