The purpose of this study is to investigate a case series of patients treated with Platelet-rich plasma for thumb carpometacarpal joint osteoarthritis. Carpometacarpal arthritis is a highly prevalent condition with significant effects on quality of life and function. Meanwhile, platelet-rich plasma has been demonstrated to be an effective treatment for various musculoskeletal conditions.

The first carpometacarpal (CMC) joint at the base of the thumb is one of the most commonly affected joints by osteoarthritis (OA), with a prevalence ranging from 15-36% in females and 5-11% in males. It is also functionally debilitating, with symptoms including diminished range of motion, weakness, deformity, instability, and pain. Despite the prevalence of first CMC OA, as well as the emerging evidence of platelet-rich plasma (PRP) efficacy for various musculoskeletal conditions, there is a paucity of studies investigating the two. To our knowledge, there are three studies in the literature, resulting in a total of 27 patients with first CMC OA receiving PRP to date1.

Common nonsurgical treatment options for management of this condition include oral and topical NSAIDs, hand therapy, activity modifications, splinting and intra-articular injections. Injections have traditionally consisted of corticosteroids demonstrating variable efficacy and viscosupplementation resulting in conflicting results. Surgical options include trapeziectomy with ligament reconstruction and tendon interposition, fusion, and less commonly, implant arthroplasty.

PRP is defined as an autologous, concentrated mix of platelets and inflammatory mediators suspended in plasma, obtained by centrifuging a patient's whole blood. It is hypothesized that PRP stimulates recruitment, proliferation, and differentiation of regenerative cells via release of various growth factors such as platelet-derived growth factor-AB and -BB, transforming growth factor-β1, insulin-like growth factor-1, fibroblast growth factor-basic, epidermal growth factor, vascular endothelial growth factor, and interleukin (IL)-12. The platelets in PRP have anti-inflammatory properties with modulators including IL-1 receptor antagonist, soluble tumor necrosis factor receptor I and II, IL-4, IL-10, IL-13 and interferon γ. Although PRP has been used for numerous musculoskeletal conditions, varying methods of extraction, different types of PRP, and lack of standardized reporting on the detailed biologic makeup of PRP has caused difficulties with interpretation and comparison of studies investigating its use. For these reasons, there has been a call for the standardization of PRP in clinical use.

The primary aim of this study was to assess (1) outcomes of PRP injection among patients with first CMC OA, and (2) the biologic characteristics of PRP injectate. The secondary aims were to describe the injection technique used at our institution and analyze the relationships between patient demographics, PRP biologic characteristics, and patient outcomes.

Inclusion Criteria:

- Patients who previously underwent PRP injection of their first CMC joint.

Exclusion Criteria:

- Individuals less than 18 years of age.

Those with CMC OA who received PRP injections