Microstructure features and pathology of trabecula in different regions of femoral head necrosis

Objective To analyze the microstructure of trabecula in different regions of femoral head necrosis. Methods Clinical and imaging data about 10 patients(6 males and 4 females) with non-traumatic femoral head necrosis who underwent total hip arthroplasty in our hospital from 2011 to 2013 were retrospectively analyzed. Samples were taken from the healthy, sclerotic and necrosed regions of the patients. The following parameters were analyzed, including the bone mineral density(BMD), bone mineral content(BMC), bone surface/ bone volume(BS/BV) ratio, bone volume fraction(BVF), structure model index(SMI), number of trabecular plates, thickness of trabecular plate, and trabecular space. Results The spatial structure of trabecula was significantly changed in necrosed and sclerotic regions of femoral head. The trabecula was significantly thicker and the BVF was significantly higher in necrosed region than in healthy region(P0.05). No significant difference was found in the BMD, the number of trabecular plates, the thickness of trabecular plate, and the BS/BV ratio between the two groups(P0.05). The BMD and BMC, the BVF, and the thickness of trabecular plate were significantly lower while the trabecular space was significantly wider in necrosed region than in healthy region(P0.05). No significant difference was found in the thickness of trabecular plate and the BS/BV ratio between the two groups(P0.05). Conclusion The spatial structure and pathological features of trabecula are different in different necrosis regions of femoral head. The continuity of trabecula in necrosed region is disrupted, with its structure disarranged and thickened, the number of trabecular plates increased, and the trabecular space narrowed. However, the structure of trabecula is intact and its thickness is even in the healthy region.