Resected, autoclaved, and reimplanted bone supplemented with allogeneic demineralized bone matrix (DABM) was compared with nonsupplemented bone in the reconstruction of bilateral ulnar defects in seven adult rabbits. The reconstructions were studied in vivo with the use of serial radiography, scintigraphy (99mTc-MDP), and bone mineral determination. After sacrifice at 16 weeks, the ulnar specimens were analyzed with the use of high-resolution radiography, autoradiography (45Ca), and histologic study. Scintigraphically, the uptake was significantly higher in the DABM-supplemented implants during the entire investigation. Bone mineral content was significantly higher at four and eight weeks in the DABM-supplemented implants, compared with the nonsupplemented implants, but later it equalized. New bone formation, as reflected by 45Ca incorporation, still occurred at 16 weeks in both types of implants, but it was more intense in the DABM-supplemented ones. Radiography and histologic analysis showed more new bone in the DABM-supplemented reconstructions than in the nonsupplemented ones. High-resolution radiography showed complete incorporation of all seven DABM-supplemented implants, whereas there was nonunion in five of seven nonsupplemented reconstructions. The current study indicates that resected, autoclaved, and reimplanted diaphyseal segments supplemented with demineralized allogeneic bone matrix incorporate better than nonsupplemented implants of autoclaved autologous bone.
From the Department of Orthopaedic Surgery, Karo-linska Hospital, Stockholm, Sweden.