Bone Grafts and Substitutes — MCQs

Question 11: Which of the following has the greatest concentration of osteogenic cells?

• A. Marrow- cancellous graft. (Correct Answer)
• B. Marrow- cortical graft.
• C. Costochondral graft.
• D. Cortical graft

Explanation: ***Marrow- cancellous graft*** - **Cancellous bone** contains a high concentration of **bone marrow**, which is rich in **osteogenic stem cells** and growth factors essential for bone formation. - These cells contribute significantly to **osteogenesis**, making cancellous grafts potent for bone healing and fusion. *Marrow- cortical graft* - While cortical grafts provide structural support, the **bone marrow** within them is less abundant and less readily accessible compared to cancellous grafts. - The primary contribution of a cortical graft with marrow is **mechanical strength**, with less emphasis on osteogenic cell concentration. *Costochondral graft* - A costochondral graft includes both **cartilage** and bone, making it useful for specific reconstructions, such as mandibular condyle regeneration. - However, its primary osteogenic potential comes from the osseous component, which typically has a lower concentration of osteogenic cells compared to a cancellous bone graft. *Cortical graft* - **Cortical bone** is dense and provides significant **structural support**, but it contains very few **osteogenic cells** and has limited intrinsic capacity for new bone formation. - Its main roles are providing **load-bearing strength** and acting as a scaffold, rather than contributing a high concentration of osteogenic cells.