The use of injectable orthobiologics for knee osteoarthritis: A formal ESSKA-ORBIT consensus. Part 2—Cell-based therapy

Purpose: This European Society of Sports Traumatology, Knee Surgery and Arthroscopy (ESSKA) formal consensus aims to provide evidence- and expert opinion-based recommendations for the use of point-of-care- and expanded-cell-based therapy (CBT) in the treatment of knee osteoarthritis (OA), focusing on indications, preparation, and administration. Methods: A multidisciplinary group of 77 leading experts in musculoskeletal regenerative medicine from 22 European Countries formed a steering group, a rating group, and a reader group. The steering group developed 23 questions, originating from 27 statements. The statements were graded from A (high-level scientific evidence) to D (expert opinion). The question-statement sets were scored by the rating group from 1 to 9 according to the level of agreement. The document was then assessed for geographic adaptability by the reader group composed of representatives from ESSKA-affiliated societies. Results: Overall, the statements received a mean score of 8.2 (standard deviation: 0.3) points out of a possible 9 and a median score of 8 (range: 6–9). Among the 27 statements, 9 were considered appropriate with strong agreement, and 18 were considered appropriate with relative agreement. Five statements received a recommendation level of A or B, and 22 were rated as C or D. In terms of geographic adaptability, 18 affiliated ESSKA Societies expressed support, two were opposed, and two abstained. CBT has demonstrated consistent clinical benefits, particularly in pain and function improvement up to 12 months, supporting its use for patients with Kellgren–Lawrence (KL) Grades 1–3 knee OA, with some benefits, though inferior, in selected KL Grade 4. However, due to limited high-quality studies and a lack of clear superiority over other injectables, CBT should be considered as a second-line treatment option. Conclusions: The consensus document acknowledges ongoing debate about CBT's full effectiveness, though evidence suggests potential clinical benefits in pain relief and functional improvement. CBT are supported as a second-line injectable treatment for KL 1–3 knee OA 1–3, with some benefits shown in Grade 4 too. However, gaps remain in high-quality studies and treatment protocols. Nevertheless, evidence suggests that CBT may be seen as an alternative to traditional injectables like corticosteroids and hyaluronic acid, given the longer-lasting benefits, and could currently be considered after other non-operative treatment fails. Level of Evidence: Level I.