Archives of orthopaedic and trauma surgery
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In three patients a mechanically well-fixed Mathys Ceros 80 (Ha) hydroxyapatite-coated acetabular component was revised 2, 5 and 13 months after total hip replacement due to component malposition. In each case there was a thin cellular connective tissue membrane between hydroxyapatite and bone, the main cell type being fibroblast with only occasional giant cells. Immunohistological analysis revealed some MHC locus II antigen positive cells that were identified as monocytes. ⋯ Hydroxyapatite induced only a slight interleukin-2 receptor expression that did not differ from culture medium on days 1, 3 and 5. CD4 and CD8 positive lymphocytes as well as monocytes were not seen attached to hydroxyapatite particles during the culture days. Our findings suggest that hydroxyapatite is an immunologically inert implant material.
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Arch Orthop Trauma Surg · Jan 1991
Usefulness of a new technique for hind limb immobilization in rats for the study of tendon healing.
To study wound repair in rat Achilles tendon, we utilized a novel surgical method for immobilizing only one hind limb. In this technique, the femoral vessels were preserved while the skin, muscles, nerves and the shaft for the femur were transected. The limb was then rotated and sutured to lie on the posterolateral flank of the animal. ⋯ In 2 weeks, the gap was completely occupied by fibrovascular tissue that was beginning to align along the long axis of the tendon. By the 4th week, remodeling had occurred and the site of the wound had almost blended with the rest of the tendon. We conclude that this new technique of hind limb immobilization causes little stress on the animal, and it can be useful for the study of tendon healing.
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Five fractures of the capitellum were fixed with a Herbert screw. Three patients had a type 1 fracture and two patients had a type 2 fracture. ⋯ In one patient the fragment was fixed from the joint line. The fragment underwent avascular necrosis with poor clinical result.