Aims: The aim of this study was to evaluate the long-term results of osteoarticular allografts operated during the years 1973–1992. Materials: 33 osteoarticular allograft operations were performed because of malignant (14) and benign tumors (19). The mean follow-up time was 15 years. Eight patients were excluded because of death (5) and amputation (3). Results: 25 (76%) of the grafts survived more than 10 years. 18 were whole-joint grafts and 7 hemi-joint grafts. 13 grafts situated in proximal tibia, 11 in distal femur and one in distal tibia. So far three cases have been converted to arthroplasty and two to arthrodesis. 20 grafts are still functioning. 19 of them are excellent or good according to Mankin score. Whole-joint and hemi-joint allografts were clinically equally good. Clear degeneration is seen in every joint and during the time the range of motion tends to decrease because of osteoarthrosis but clinically the patients were surprising painless. Conclusions: The operation is demanding and may cause a large variety of complications, for instance infection, non-union, fatigue fracture, nerve palsy and joint instability. On the other hand, the graft may provide weight-bearing bone that will incorporate biologically into the host skeleton and function almost as a normal joint for years. As prosthesis solutions have also problems and tend to fail with time, osteoarticular allografts should be taken to serious consideration when the first operation method is chosen.

Aims: Wood is a product of nature, has a structural architecture resembling bone and is chemically polymer-like. Birchwood modified with heat and humid air was selected to study its possibilities for bone reconstruction. Methods: Bulk birchwood was prepared for 2–3 hours at temperature of 220°C in humid air, this modifies the wood chemically and physically. 16 cone shaped implants 7x4 mm in size were carved from the heat treated material (Bioactive Wood Bone, BWB) and implanted by press-fit technique into holes drilled in the distal femurs of rabbits. Untreated cones served as controls. The resected knees were embedded in plastic (Techmont, Kulzer GmBH). For evaluation histology, histomorfometry and scanning electron microscopy (SEM) were carried out. Results: In vitro SEM showed the canal structures of the wood. In vivo no articular hydrops or wound infections were seen. At 4 and 8 weeks an inflammatory cellular reaction of a mild degree with some histiocytes was observed. At 8 and 20 weeks the implant’s surface was in connection with the surrounding bone and connective tissue. Bone-implant contact at the interface required proper press-fit technique. At 8 and 20 weeks histometry revealed new bone growth covering 21% (mean, range 6–41%) of the implant surface resembling the osteoconductive bonding characteristic of biomaterials. Conclusions: Modified heat treated wood showed biocompatibility and osteoconductivity in cancellous bone defect. A bone bonding-like-phenomenon observed at the interface between the birch implant and bone illustrates it’s potentials for use as a bone substitute.

Aims: We wanted to compare bioactive glass granules with autogenous bone in operative treatment of lateral condyle fractures. Methods: 25 patients, 12 females and 13 males, (from 36 to 69 years) were operated at our institute for lateral condyle fracture. The patients were randomized into autogenous bone (AB) and bioactive glass (BG) group. There were no statistical difference between the two groups with regard to genre, patient age, type of fracture or comminution and depression of the joint surface. The study protocol was approved by the local hospital ethical committee and written consent of the patients was achieved. A routine AO operation protocol was used in all patients. Prior to operation plain x-ray þlms and three-dimensional computed tomography (3D CT) was performed in order to reveal the anatomy of the fracture. The postoperative follow-up included 3D CT, plain þlms and clinical examination after the operation and at 6 weeks, 3, 6, 12 and 36 months. Results: The mean preoperative articular depression in the BG group was 9 mm (±4 mm) and in the AB group 7mm (±2 mm). Postoperatively the articular surface remained 2 mm (± 3 mm) depressed in both groups. Threafter the articular height remained unchanged. As evaluated by CT and plain þlms the bioactive glass granules were incorporated with the surrounding bone at 3 months. No adverse reactions due to bioactive glass were observed. The clinical results were equal in both groups. Conclusions: The clinical and radiological results using bioactive glass were as good as those when autogenous bone was used.

Aims: To develope a prosthesis with porous surface based on polymer technology of metacrylates, bioactive glass S53P4 and glassfiber reinforcement to treat segmental bone defects. Methods: A sylindrical prosthesis matching anatomically shape of the rabbits tibia was prepared from bioactive glass S53P4 (granule size 90–315 μm) and polymethylmetacrylate (PMMA). The polymerization was perfomed extracorporally thus reducing the amount of toxic monomers introduced into the body. Three groups of prosthesis were made: 1. Surface of the bulk grinded to expose glass granules at its surface 2. Surface prepared porotic, porediameter 50–300 μm and biomechanical properties increased by glass fiber reinforcement 3. Prosthesis made from PMMA serving as control group. A 12 mm segmental defect was sawed in the tibia and replaced with the prosthesis. Prosthesis was fixed with DCP-plate. Evaluation was made after 4, 8 and 20 weeks by plain radiographs, CT, histology, histometry and SEM. Results: Bone incorporation at the interface was evident in areas where good tissue contact was obtained. Porotic surface structure enhanced bone ingrowth. Histometry revealed 16–30% bone contact at the interface in groups 1 and 2. Conclusions: Study illustrates views on biotechnical innovations combining bioactive materials to be used for bone reconstruction. This composite material has potentials to be used as new prosthesis material and artificial bone substitute.