A single step, centrifuge-free method to harvest bone marrow highly concentrated in mesenchymal stem cells: results of a pilot trial

Intra-articular injection of bone marrow aspirate concentrate (mesenchymal stem cells) in KL grade III and IV knee osteoarthritis: 4 year results of 37 knees

Cell based therapies are increasingly used and results of bone marrow aspirate concentrate (BMAC) show encouraging short- to middle term results, superior to hyaluronic acid and platelet rich plasma (PRP). Most studies describe patients with mild to moderate arthritis and results of patients with KL III and IV osteoarthritis of the knee are limited to short term evaluations. Hence, the aim of this prospective study was to investigate the mid-term outcome of BMAC injections in patients with severe osteoarthritis of the knee. The BMAC was retrieved from the iliac crest as previously published with the "reorientation technique" from the iliac crest in supine position in analgosedation and injected into the patients' osteoarthritic knees. Patients were followed-up for 4 years. WOMAC, IKDC, SF 36 and walking distance were measured in a total of 37 participants. There was an improvement of IKDC and WOMAC from the first year onwards and a significant improvement beginning from year 2 up to the mid-term follow-up: IKDC increased significantly from 56 ± 12 (range 34-81) to 73 ± 13 (range 45-100), p < 0.001. WOMAC decreased significantly from 40 ± 23 (range 6-96) to 18 ± 18 (range 0-67), p < 0.001. 35 of 37 knees improved regarding IKDC and WOMAC score from the first to the last follow-up. Not a single protheses had to be implanted. Elaborate statistical analysis was done to exclude covariates and confounders (age, time, BMI,…). In summary, this is the first study on BMAC injections into 37 osteoarthritic knees with a 4-year follow up showing significant improvements in IKDC and WOMAC scores, and with a 95% success rate and significant improvement in walking distance.Clinical relevance Describes the 4-year outcome of BMAC injections for knees with severe osteoarthritis.

Inflammatory Treatment Used to Mimic Osteoarthritis and Patients' Synovial Fluid Have Divergent Molecular Impact on Chondrocytes In Vitro

Osteoarthritis (OA) is a chronic disease characterized by joint tissue disruption and inflammation with a paucity of therapeutic options. Chondrocyte in vitro models are commonly used as the first step in evaluating new approaches and rely on the stimulation of an OA-like phenotype with inflammation often the method of choice. Inflammatory priming is frequently based on cytokines used at concentrations very far from the reality in the patients' synovial fluid (SF). The aim of this work was to compare the transcriptional response of chondrocytes to different inflammatory conditions: the high levels of IL1β that are used for standardized inflammation protocols, OA-SF, IL1β, IL6 and IFNγ at SF-like concentrations both individually and simultaneously to mimic a simplified "in vitro" SF. Both high IL1β and OA-SF strongly influenced chondrocytes, while SF-like concentrations of cytokines gave weak (IL1β alone or in combination) or no (IL6 and IFNγ alone) outcomes. Chondrocytes under the two most powerful polarizing conditions had a clearly distinct fingerprint, with only a shared albeit molecularly divergent effect on ECM stability, with IL1β mainly acting on ECM degrading enzymes and OA-SF accounting for a higher turnover in favor of fibrous collagens. Moreover, OA-SF did not induce the inflammatory response observed with IL1β. In conclusion, although partially similar in the endpoint phenotype, this work intends to encourage reflection on the robustness of inflammation-based in vitro OA models for molecular studies on chondrocytes.