Histological Observation Of Subchondral Bone Following Collapse Of Osteonecrosis Of The Femoral Head

Background and ObjectiveFemoral head necrosis orthopedic common multiple diseases, mainly concentrated in young and middle-aged population, and increasingly younger, such as the lack of timely and correct diagnosis, appropriate treatment, will inevitably lead to the collapse of femoral head as the disease progresses, the bonethe formation of arthritis. Subchondral bone in the femoral head necrosis progress plays a very important role, are related to changes in subchondral bone lesions collapse of the femoral head, subchondral bone changes affect the healing of the bone graft, and ultimately affect the insurancehead treatment success or failure. This study of total hip arthroplasty femoral head to do a biopsy, observed after the collapse of the femoral head necrosis of subchondral bone histology characteristics to explore the relationship between the morphological changes of necrosis of the femoral head cartilage bone grafting difficult healing.MethodsFrom August2011to February2012,25specimens of femoral head were collected from patients who underwent total hip replacement due to osteonecrosis of the femoral head. There were eighteen males and seven females with an average age of38.5years. Specimens of subchondral bone from different parts of the femoral head including normal, junctional and necrotic area were obtained from all femoral head specimens. There subchondral bone specimens were labeled and decalcified paraffin-embeded. Then pathological section were stained with HE method. Observation methods included gross morphology, and histological observation. Histological observation included cartilage and subchondral bone from different parts.ResultsFemoral head collapse occurred in the superlateral part. Subchondral bone were separated from calcified cartilage. Histologically, fracture were observed through the whole subchondral bone to the calcified cartilage. In the necrotic area, the integrity of the subchondral bone were damaged with separation from the calcified cartilage.ConclusionCollapsed femoral head necrosis were observed histologically with fracture through the whole subchondral bone to the calcified cartilage with seperation of subchondral bone from calcified cartilage in necrotic area. Difficulty of bonegraft healing with avascular calcified cartilage may be responsible for poor clinical outcome of head-preserving procedure in collapsed osteonecrosis of the femoral head.