Early clinical use has suggested that bone graft obtained from the human femur using the RIA system is available in large quantities, may be associated with less pain when compared to conventional methods of autograft harvest, and may provide bioactive substances in addition to bone that aid in the healing process.
All patients enrolling in this study will be scheduled for bone grafting of their fracture or nonunion using the RIA system, irregardless of their participation in the study. There is pain associated with the harvest of the bone, but it will be the same whether the patient is enrolled in the study or not.
A total of sixteen patients will be enrolled in this study, eight will have large (2.8 - 5.6 mm) Beta-Tricalcium Phosphate (ChronOS) granules in the second filter, eight will have medium (1.4 - 2.8 mm) Beta-Tricalcium Phosphate (ChronOS)granules. All patients will be enrolled after obtaining informed consent. In order to be eligible for the study, the patients must already be scheduled for bone grafting of a fracture or nonunion with harvest of autologous graft material from their femur using the RIA system. The reaming procedure will be conducted using the trochanteric entry portal through the tip of the greater trochanter. The reamer size will be determined using fluoroscopy to measure the medullary canal at the isthmus of the femur. All bone graft harvest will be obtained using a single pass reaming over a guide wire placed centrally in the distal femur. Two 750 micrometer filters will be placed in series at the suction end of the RIA. The first filter will collect the bone, and the second filter will be filled with Beta-Tricalcium Phosphate. Three samples (\< 1 cc) of the bone will be collected from the first filter. The first sample will be from the top of the filter, the second sample will be obtained halfway down the filter, and the final sample will be obtained from the bottom of the filter. Similarly, three samples of Beta-Tricalcium Phosphate will be obtained from the second filter. Each of these samples will also be less than 1 cc of material. The first sample will be from the top layer, the second sample will be from the middle of the Beta-Tricalcium Phosphate layer, and the final sample will be from the bottom of the filter. The middle of each filter layer will be determined by measuring the filter sample with a ruler and dividing by two. Each of these samples will be stored in dry ice and transported to the Department of Surgery laboratories run by Dr. Irshad Chaudry for processing as described below. We will also obtain a single sample of the fluid effluent that is normally discarded as part of the procedure. That sample will be analyzed for the same proteins and factors described below.
All patients will undergo a needle biopsy of their ipsilateral iliac crest while under general anesthesia for their surgical procedure. The bone biopsy will be taken through the surgical incision used for placing the reamer irrigator aspirator in most cases. If a patient requires only a small incision for placing the reamer, which precludes needle biopsy through the surgical incision, then the needle biopsy will occur through a small (\< 1 cm) incision directly over the iliac crest. The iliac crest biopsy will also be immediately placed on dry ice and transported to the Department of Surgery laboratories of Dr. Chaudry for evaluation. After the samples have been obtained, the scheduled surgical procedure will be completed.
