BMAC therapy — bone marrow concentrate

BMAC (Bone Marrow Aspirate Concentrate) is concentrated bone marrow. Under local anaesthesia, 50–60 ml of bone marrow is aspirated from the posterior superior iliac crest using a special needle. The aspirate is centrifuged in a dedicated system (Arthrex Angel, Magellan, BioCUE) to a 6–10 ml concentrate containing haematopoietic stem cells, mesenchymal stem cells, osteogenic precursors and signalling molecules.

BMAC contains haematopoietic + mesenchymal cells + osteogenic precursors — optimal for bone regeneration (necrosis, fractures, osteoporotic injuries). Lipogems® contains only mesenchymal cells in stroma — optimal for cartilage, discs and tendons. The combination of BMAC + Lipogems® is the gold standard for severe cases (advanced necrosis with cartilage damage).

Under local anaesthesia with light sedation, the procedure is comfortable. The harvest itself takes 5–10 minutes. A brief "deep" discomfort during aspiration is possible (lasting 1–2 seconds for each portion). Afterwards, mild soreness at the harvest site lasts 24–48 hours and is easily controlled with paracetamol. Hospitalisation is not required.

From 60 ml of bone marrow, ~6–10 ml of concentrate is obtained, containing 2–5 million mesenchymal stem cells + 50–80 million haematopoietic cells + numerous osteogenic precursors. The MSC concentration is lower than in Lipogems® (15–20 million), but the qualitative composition is unique and irreplaceable for bone regeneration.

Most often, one procedure is sufficient. For ARCO II avascular necrosis, occasionally a course of two procedures spaced 8–12 weeks apart is used. For non-union fractures, one procedure, with a repeat after 4 months if needed. For severe stage III OA, a one-stage combination of BMAC + Lipogems® — one procedure.

For avascular necrosis — pain reduction and improved gait at 6–8 weeks; morphological MRI improvement at 6 months. For stress fractures — accelerated consolidation visible on MRI at 4–6 weeks vs the standard 8–12. For osteoarthritis — change at 8–12 weeks, maximum at 6 months.

Very. Serious complications occur in <0.1% (systematic review by Cassano et al. 2018). Possible minimal risks: a haematoma at the harvest site (rare, resolves in 7–10 days), transient local pain, very rarely a vasovagal reaction (5 cases per 100,000 procedures). With strict asepsis and experienced operators, safety is virtually ideal.

Not only is it possible — it is recommended. BMAC in patients with osteoporosis has a dual effect: 1) it accelerates fracture consolidation; 2) when used systemically (intraosseously into a zone of probable fracture), it stimulates local osteogenesis. It does not replace baseline therapy for osteoporosis (bisphosphonates, denosumab) but is a critical adjunct when fractures are present.

The number and proliferative activity of MSCs in the bone marrow decline with age (~30% lower after 60 vs 30-year-olds). However, functional capacity (differentiation, growth-factor secretion) is preserved. We therefore harvest more material from older patients (60 ml instead of 30) and often combine BMAC with Lipogems® to enhance the effect.