PLATELET DOSE AND NUMBER OF PLATELET-RICH PLASMA APPLICATIONS IN THE CONSERVATIVE TREATMENT OF PARTIAL-THICKNESS ROTATOR CUFF TEARS: PARAMETERS ASSOCIATED WITH THERAPEUTIC EFFECTIVENESS IN AN INTEGRATIVE REVIEW

Abstract

Partial-thickness rotator cuff tears are a frequent cause of shoulder pain and functional impairment, and platelet-rich plasma (PRP) has been investigated as a conservative biological treatment. However, substantial heterogeneity in platelet concentration, administered volume, total platelet dose, number of injections, and treatment intervals limits direct comparison among therapeutic protocols. This integrative review aimed to analyze platelet-dose parameters and PRP administration regimens used in the conservative treatment of partial-thickness rotator cuff tears and their relationship with clinical and functional outcomes. Clinical studies, prospective investigations, systematic reviews, meta-analyses, and methodological studies addressing PRP characterization were analyzed. Data extraction included PRP volume, platelet concentration when available, platelet dose, number and interval of injections, preparation characteristics, follow-up duration, pain, and shoulder function. The analyzed protocols showed considerable variability, with administered volumes ranging from 2 to 6 mL per injection and treatment regimens ranging from one to four applications. Single-injection protocols predominated, whereas repeated regimens differed in both the number and timing of applications. Available evidence documented improvements in pain and functional outcomes after PRP treatment at specific follow-up periods; however, absolute platelet concentrations and total platelet doses were not consistently reported across studies. Consequently, the available evidence did not establish a definitive linear dose-response relationship or demonstrate the superiority of a specific number or interval of applications. The findings indicate that platelet concentration, administered volume, platelet dose, cumulative exposure, and injection regimen should be treated as distinct variables. Standardized reporting and prospective comparative studies controlling these parameters are required to determine whether an optimal platelet dose and administration regimen exists for conservative treatment of partial-thickness rotator cuff tears.