Achilles tendon ruptures are very common tendon ruptures and their incidence is increasing in modern society, resulting in work incapacity and months off sport, which generate a need for accelerated and successful therapeutic repair strategy. Platelet-rich plasma (PRP) is emerging as adjuvant human blood-derived constructs to assist Achilles tendon rupture treatment. However, myriad PRP preparation methods in conjunction with poor standardization in the modalities of their applications impinge on the consistent effectiveness of clinical and structural outcomes regarding their therapeutic efficacy. The purpose of this review is to provide some light on the application of PRP for Achilles tendon ruptures. PRP has many characteristics that make it an attractive treatment. Elements such as the inclusion of leukocytes and erythrocytes within PRP, the absence of activation and activation ex vivo or in vivo, the modality of application, and the adjustment of PRP pH can influence the biology of the applied product and result in misleading therapeutic conclusions. The weakest points in demonstrating their consistent effectiveness are primarily the result of myriad PRP preparation methods and the poor standardization of modalities for their application. Selecting the right biological scaffold and applying it correctly to restitutio ad integrum of ruptured Achilles tendons remains a daunting and complex task.

Background/Objectives: Severe knee osteoarthritis (KOA) is a degenerative disease that significantly affects quality of life (QoL). Although intra-articular (IA) injections of plasma rich in growth factors (PRGF) have proven effective, the subchondral bone plays a crucial role in pathogenesis. The objective of this study was to evaluate the efficacy of intraosseous (IO) PRGF infiltrations in comparison with a saline placebo, followed by the conventional standard treatment of three IA PRGF injections, in enhancing clinical outcomes in patients suffering from severe KOA. Methods: A prospective, randomized, double-blind, multicenter clinical trial was conducted. Eighty-six patients with Kellgren–Lawrence grade III-IV KOA were randomly assigned to two groups: one received an IO infiltration of PRGF and the other received an IO saline solution. Both groups subsequently received three IA PRGF injections. Clinical outcomes were assessed using the KOOS and WOMAC scales at baseline and at 3, 6, and 12 months. Results: Both groups showed a statistically significant improvement in all KOOS and WOMAC subscales at all follow-up points compared to their baseline values. However, the group that received the IO PRGF infiltration demonstrated significantly greater improvements in nearly all domains of the KOOS and WOMAC scales (pain, symptoms, function, and quality of life) at 3, 6, and 12 months compared to the saline group (p < 0.05). No serious adverse events were recorded. Conclusions: The combination of intraosseous and intra-articular PRGF infiltrations is a superior therapeutic strategy to the combination of intraosseous saline solution and intra-articular PRGF for treating severe KOA. These findings suggest that treating the subchondral bone directly with PRGF has a significant and clinically relevant therapeutic effect, resulting in greater pain reduction and functional improvement at one-year follow-up.