Krishna Anand

Introduction. Lateral epicondylitis (LE) is caused by the overuse of the wrist extensors, typically from repetitive movements with the forearm in the pronated position¹. Treatment options for patients with aggravating and persistent LE are limited non-operatively¹. Current modalities of treatment include non-steroidal anti-inflammatory drugs, corticosteroid injections, and physical therapy^1,2 – however, these modalities often fail to support long term relief and healing. Platelet-rich plasma (PRP) injections are a new and cutting-edge technology in which a tiny amount the patient’s blood is extracted, supplemented with growth factors, and injected back into the damaged tissue for recovery². There is limited literature on the success of plasma-rich protein (PRP) injections in patients with LE – in fact, most systematic reviews argue per contra². This is a controversial modality of treatment amongst orthopedists. The purpose of this study is to assess genomic and PRP composition in which PRP may be a suitable treatment option for LE^1,2,3,4,5. Methods. A systematic review of the literature in lateral epicondylitis was conducted to assess studies that concluded PRP was not a recommended treatment and determine specifications as to how the PRP was made and the experimental strategies for identifying efficacy². Next, papers with PRP-serum compositions were evaluated in successful and unsuccessful patient outcomes^3,4. Finally, a study that evaluated the use of genomic screening in PRP efficacy was investigated⁵. Results. Most studies evaluate patient characteristics in relation to the success of PRP but fail to go beyond the demographic point of view and study the composition of PRP^1,2. TGF-β-mediated mechanisms play a significant role in the treatment of LE^3,4. Leukocyte-rich PRP, while not generally used for tendinopathies, improve outcomes for LE³. Finally, within the PDGF-B gene, the polymorphic variants with TT (rs2285099)/ CC (rs2285097) and AA (rs2247128) homozygotes all showed improved outcomes⁵. Conclusion. Current literature on PRP use in LE limited in its mechanistic understanding of the pain relief process. Within the United States and in a world of rapid genomic testing, a diagnostic tool for PRP candidacy should evaluate nucleotide polymorphisms in the PDGF-B gene⁵. Further, for optimal results across the board, L-PRP should be adopted with intentionally high TGF-β^3,4. With these criteria in mind, PRP should be used in LE, yet this is just a start until additional research in the biogenetics of PRP illuminates a more efficacious treatment vignette for PRP.

1. Park, H. B., Gwark, J. Y., Im, J. H., & Na, J. B. (2021). Factors Associated with Lateral Epicondylitis of the Elbow. Orthopaedic journal of sports medicine, 9(5), 23259671211007734. https://doi.org/10.1177/23259671211007734
2. Linnanmäki, L., Kanto, K., Karjalainen, T., Leppänen, O. V., & Lehtinen, J. (2020). Platelet-rich Plasma or Autologous Blood Do Not Reduce Pain or Improve Function in Patients with Lateral Epicondylitis: A Randomized Controlled Trial. Clinical orthopaedics and related research, 478(8), 1892–1900. https://doi.org/10.1097/CORR.0000000000001185
3. Watts, A. C., Morgan, B. W., Birch, A., Nuttall, D., & Trail, I. A. (2020). Comparing leukocyte-rich platelet-rich plasma injection with surgical intervention for the management of refractory tennis elbow. A prospective randomised trial. Shoulder & elbow, 12(1), 46–53. https://doi.org/10.1177/1758573218809467
4. Lim, W., Park, S.H., Kim, B., Kang, S.W., Lee, J.W. and Moon, Y.L. (2018), Relationship of cytokine levels and clinical effect on platelet-rich plasma-treated lateral epicondylitis. Orthop. Res., 36: 913-920. https://doi.org/10.1002/jor.23714
5. Niemiec, P., Szyluk, K., Balcerzyk, A., Kalita, M., Jarosz, A., Iwanicka, J., Iwanicki, T., Nowak, T., Negru, M., Francuz, T., Garczorz, W., Grzeszczak, W., Górczyńska-Kosiorz, S., Kania, W., & Żak, I. (2021). Why PRP works only on certain patients with tennis elbow? Is PDGFB gene a key for PRP therapy effectiveness? A prospective cohort study. BMC musculoskeletal disorders, 22(1), 710. https://doi.org/10.1186/s12891-021-04593-y