fumarates and Tibial-Fractures

The bioactivity of a nano-hydroxyapatite-augmented, bioresorbable bone graft substitute made from the unsaturated polyester, poly(propylene fumarate), was analyzed by evaluating biocompatibility and osteointegration of implants placed into a rat tibial defect. Three groups of eight animals each were evaluated by grouting bone graft substitutes into 3-mm holes that were made into the anteromedial tibial metaphysis of rats. Thus, a total of 24 animals was included in this study. Two different formulations varying as to the type of hydroxyapatite were used: Group 1 - nano-hydroxyapatite, Group 2 - micron-hydroxyapatite, with a Group 3 control defect remaining unfilled. Animals of each of the three groups were sacrificed in groups of eight at postoperative week three. Histologic analysis revealed best superior biocompatibility and osteointegration of bone graft substitutes when nanohydroxyapatite was employed. At three weeks, there was more reactive new bone formation in this group when compared to the micron-hydroxyapatite group. The control group showed incomplete closure of the defect. This study suggested that nano-hydroxyapatite may improve upon the bioactivity of bone implant and repair materials. The model scaffold used in this study, poly(propylene fumarate), appeared to provide an osteoconductive pathway by which bone will grow in faster. Clinical implications of the use potential advantages of nano-hydroxyapatite on bone repair and orthopaedic implant design are discussed.

Topics: Absorbable Implants; Animals; Bone Substitutes; Bone Transplantation; Durapatite; Equipment Failure Analysis; Fumarates; Male; Osseointegration; Polypropylenes; Radiography; Rats; Rats, Sprague-Dawley; Tibial Fractures; Treatment Outcome

We report about a rare case of a pathological fracture of the shank following earlier pathological fractures at other locations in a comparatively young female patient with no history of trauma. There were no known diseases other than psoriasis. The shank fracture was treated surgically by osteosynthesis. Osteoporosis, myeloma, or malignancy as causative factors of this fracture could be excluded. Scintigraphy showed an enhancement, especially at the extremities. Other than reactive bone growth, histological examination revealed no further aspects. Laboratory analysis indicated a massive lack of vitamin D3. After transferring the patient to the internal department of our hospital, long-term medication with fumaric acid was determined to be the reason for the osteomalacia of a Fanconi's syndrome. Three months after cessation of these medicaments and treatment with active vitamin D3 metabolites, the patient was free of complaints. The radiographs showed an essential improvement of the demineralization.

Topics: Adult; Ankle Injuries; Diagnosis, Differential; Fanconi Syndrome; Female; Femoral Neck Fractures; Fracture Fixation, Internal; Fractures, Spontaneous; Fumarates; Humans; Psoriasis; Radiography; Reoperation; Tibial Fractures