Intra-articular injection of bone marrow aspirate concentrate in end stage knee osteoarthritis: 4 year results of 37 knees

Abstract Purpose: 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 short term results of patients with severe osteoarthritis of the knee. 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. Methods: The BMAC was retrieved from the iliac crest as previously published with the “reorientation technique” from the iliac crest in prone position in sedoanalgesia 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. Results 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<.001. WOMAC decreased significantly from 40±23 (range 6-96) to 18 ±18 (range 0-67), p<.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,…) . Conclusion 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. Level of Evidence: Level I