Bone Marrow Aspiration Site
Preferred Site in Adults
The posterior iliac crest is the preferred site for bone marrow aspiration in adults due to superior safety, patient comfort, and specimen quality. 1, 2, 3
Rationale for Posterior Iliac Crest Selection
Safety profile: The posterior iliac crest has minimal risk of serious complications compared to sternal aspiration, which carries a rare but potentially fatal risk of cardiac tamponade from inadvertent penetration of the sternum 3
Patient comfort: This site is psychologically less traumatic for patients and can be performed with minimal discomfort when adequate local anesthesia is utilized 2, 3
Specimen quality: The posterior iliac crest provides representative bone marrow samples equivalent to those obtained from the sternum, vertebral spine, or anterior iliac crest 2
Accessibility: The site is readily accessible and allows for both aspiration and trephine biopsy to be performed during the same procedure 1, 3
Technical Considerations for Posterior Iliac Crest Aspiration
Optimal entry angle: When entering the most medial aspect of the posterior superior iliac spine (PSIS), use an angle of 24° regardless of patient sex 4
Depth of advancement: The trocar can safely advance approximately 7.53 cm in males and 6.74 cm in females before reaching the anterior ilium wall 4
Ultrasound guidance: Use ultrasound to determine the precise location of the PSIS and entry point, as landmark palpation alone is unreliable and inaccurate 4
Multiple sampling technique: If large sample volumes are required for multiple diagnostic tests, change the bone marrow aspiration site or reinsert the needle at different angles through the original puncture site to avoid hemodilution 5
Alternative Sites for Children and Infants
In pediatric patients, particularly infants, the anterior tibial plateau is the preferred alternative site, while older children can undergo posterior iliac crest aspiration similar to adults. 3, 6
Pediatric Site Selection Algorithm
Infants and young children: The anterior tibial plateau provides safe access with adequate bone marrow samples in this age group 3
Older children: The posterior iliac crest becomes the preferred site once the pelvis has developed sufficiently, typically after early childhood 3, 6
Sternum: This site is generally avoided in pediatric patients due to the increased risk of penetration and cardiac complications 3, 6
Critical Pitfalls to Avoid
Sternal aspiration risks: Never perform sternal aspiration without recognizing the rare but catastrophic risk of cardiac tamponade; reserve this site only when the posterior iliac crest is inaccessible 3
Inadequate anesthesia: Failure to provide adequate local anesthesia significantly increases patient discomfort and may compromise future procedures 3
Hemodilution: Aspirating excessive volumes from a single site dilutes the specimen with peripheral blood, reducing diagnostic yield; change sites or needle angles when multiple samples are needed 5
Coagulopathy: Bone marrow aspiration is not recommended for patients with impaired hemostasis without appropriate correction 6
Landmark palpation alone: Relying solely on palpation without ultrasound guidance increases the risk of incorrect needle placement and failed aspiration 4