The use of porous metallic coatings for fixation of total joint prostheses by bone ingrowth has become a widespread alternative to fixation with PMMA bone cement. However, concerns about such coatings include long-term effects of metal ion release, potential coating loss, and decreased substrate fatigue strength. The biological fixation capability of a nonporous, high-integrity plasma-sprayed CoCr coating with low surface area was compared to a conventional sintered bead coating in goat cortical and cancellous bone sites after 8 and 16 weeks of implantation. Histological evaluation showed substantial variations in fixation quality between individual animals and between surgical sites with no consistent difference between implant types. Shear testing of bone/implant interfaces showed that although conventional porous coating exhibited higher overall average shear strengths in cortical bone sites at both time periods, the differences were not statistically significant. In cancellous sites, the average shear strengths achieved with conventional porous and plasma-sprayed coatings were essentially equal. Analysis using average paired differences, however, revealed that when porous and plasma-coated implants are placed in identical sites of contralateral limbs, the plasma coatings consistently yielded higher shear strengths in cancellous bone sites at the later time period. Since current design theory for biological fixation favors metaphysical fixation, this surface may offer potential advantages over conventional porous coatings.

This experimental study reports the evaluation of a mechanical, non-suture technique for the repair of small blood vessels under the operating microscope. The method uses the Unilink implantable pinned rings on which the vessel ends are everted 90 degrees and impaled on small pins. An instrument approximates the rings and completes the anastomosis. The device was used for the end-to-end anastomosis of 80 vessels in ten beagle dogs. Both arteries (ulnar and saphenous) and veins (cephalic and saphenous) were included in the study. Vessels were assessed for patency and harvested for histologic examination and scanning electron microscopy at 4-, 16-, and 32-week implantation times. Both longitudinal and cross sections were stained using hematoxylin and eosin, Verhoeff-Van Gieson techniques for elastin, and a modified Masson's trichrome for muscle and collagen, and examined under light microscopy. Scanning electron microscopy (SEM) was completed on longitudinally bisected anastomoses. Patency rates, histology, and SEM at all implantation times of the mechanical anastomoses compared favorably with experimental investigations of suturing techniques that have appeared in the literature. This microvascular anastomotic technique provided a rapid, safe, and efficacious method for the end-to-end repair of severed peripheral arteries and veins in the dog model.

Please note that on page 558, paragraph 2, sentence 4 should read: "A final plasma-sprayed coating thickness of approximately 500 pm was obtained, which exhibited an RMS surface roughness of approximately 25 pm."

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