Quantification of bone harvested from the iliac crest using a power-driven trephine

Purpose: This study describes an alternate approach for harvesting cancellous bone from the anterior iliac crest and quantifies the amount of bone removed using a power-driven trephine without the need for an open procedure. The safety of this technique is also evaluated. Materials and Methods: Twenty-five adult cadavers were used to determine the volume and weight of bone that could be harvested using a motorized trephine. A total of 50 anterior iliac crests were sampled. Core samples of cancellous bone were measured, weighed, and the volume calculated. The harvested sites were then dissected and evaluated for perforations. These data were compared with the measurement of the first 40 consecutive cores trephined from patients requiring grafts. Results: The bone harvested took the form of a compact core measuring, on average, 33.5 mm in length and 4.0 mm in diameter. The average weight of each core was 0.44 g, and the average volume was 0.42 cm(3). Perforation to the medial aspect occurred in 4 of 50 hips, and lateral perforations occurred in 7 of 50 hips. The greatest number of perforations occurred at depths greater than 30 mm and were found in the most atrophic cadavers. The 40 cores obtained from patients averaged 34.1 mm in length and 0.46 g in weight. The average volume per core was 0.45 cm(3). Conclusions: The amount of trephinated autogenous cancellous bone procurable by means of a motor-driven trephine is suitable for cases of sinus lifting or to fill an alveolar cleft defect. Although the yield of cadaveric bone is slightly less than the amount obtainable from patients, it is a useful model to evaluate potential complications and estimate yields.