Platelet-rich plasma for jumper's knee: a comprehensive review of efficacy, protocols, and future directions

Abstract

Purpose: This comprehensive review evaluates the current state of platelet-rich plasma (PRP) treatment for jumper's knee, also known as patellar tendinopathy. The aim is to assess the efficacy of PRP as a therapeutic option compared to other available procedures, investigate the benefits and potential drawbacks of PRP infiltration, and provide insights into the optimal protocols for PRP preparation and administration.

Methods: A comprehensive literature search of English articles published up to June 2023 was conducted using PubMed and Scopus databases. Studies evaluating PRP for treating jumper's knee or patellar tendinopathy were analyzed to assess the current state of research in this field.

Results: PRP has demonstrated promising results in promoting cellular remodeling and accelerating the healing process in the jumper's knee. It shows potential benefits in pain reduction, improved function, and accelerated recovery. However, the efficacy of PRP varies depending on patient characteristics, disease severity, and the specific administration methodology. Establishing standardized PRP preparation and administration protocols are necessary to optimize its effectiveness. Further research is needed to define appropriate patient selection criteria and refine the application of PRP therapy in patellar tendinopathy management.

Conclusion: Jumper's knee is commonly managed conservatively, but there is a lack of consensus on further treatment options. PRP treatment holds promise in promoting tissue healing and repair. However, standardized protocols for PRP preparation and administration, as well as optimal dosage and number of injections, require further investigation to enhance its efficacy. Continued research efforts are necessary to ascertain the precise role of PRP and its refinement in the management of patellar tendinopathy.

Keywords: Efficacy; Jumper's knee; Knee; PRP; Patellar tendinopathy; Platelet-rich plasma.

Fig. 1

PRP injection is administered via infiltration into the patellar tendon to treat the jumper's knee. PRP platelet-rich plasma

Fig. 2

Mechanism of action of PRP. Wound healing and tissue regeneration can be accelerated at the site of tissue injury by various growth factors produced from activated platelets. PRP platelet-rich plasma; PDGF platelet-derived growth factor; VEGF vascular endothelial growth factor; TGF-β transforming growth factor β; EGF epidermal growth factor. The source is published under a Creative Commons License from Jain et al. [6]

Fig. 3

Scheme of the centrifuged blood with variants of PRP preparation. A line was drawn 5 mm above the buffy-coat layer in the separated blood, and the layer above this line was divided into two. The upper portion was designated as PPP, and the lower portion was designated as PRP A The target layer (shaded area) of the PRP system, containing LP-PRP. B When aspirating from above the target layer (shaded area), the platelet concentration obtained was relatively low, without contaminating leukocytes, representing purified PRP. C Aspirating from layers below the target layer (shaded area), platelet concentration increased, though leukocytes were retained, which was LR-PRP. PPP platelet-poor plasma; PRP platelet-rich plasma; LP-PRP leukocyte-poor-PRP; LR-PRP leukocyte-rich PRP The source is published under a Creative Commons License from Kikuchi et al. [24]