Anatomic Considerations for Posterior Iliac Crest Bone Procurement

Purpose The aim of this study was to identify the relative anatomic locations of relevant vital structures at risk for injury during posterior iliac crest bone graft procurement. Materials and Methods Twenty-one cadavers yielded 39 intact posterior ilia for dissection. The posterior superior iliac spine (PSIS) was used as the primary reference landmark. Measurements were made to the medial branch of the superior cluneal nerves, the superior branch of the middle cluneal nerves, the sciatic notch, and the superior gluteal vessels. Distances from the spinal midline to the superior cluneal nerves were recorded. Results The average distances from the PSIS to the superior and middle cluneal nerves, greater sciatic notch, and superior gluteal vessels were 5.7 cm (standard deviation, 1.22 cm), 6.55 cm (standard deviation, 1.53 cm), 5.3 cm (standard deviation, 0.71 cm), and 5.4 cm (standard deviation, 0.95 cm), respectively. The most medial superior cluneal nerve was identified at 3.0 to 4.9 cm from the PSIS in 23% of cases, at 5.0 to 6.9 cm from the PSIS in 61.5% of cases, and farther than 7.0 cm from the PSIS in 15.4% of cases. Conclusions This study illustrates that the most medial superior cluneal nerve is often closer to the PSIS than previously described and the same holds true for the greater sciatic notch and superior gluteal vessels. Knowledge of the anatomic locations of these important structures should allow the surgeon to avoid or decrease the complication rate of bone procurement from the posterior ilium.