Biologic fixation of ligament prostheses and augmentations. An evaluation of bone ingrowth in the dog

The biologic fixation (bone ingrowth) of three prosthetic ligament devices (bovine xenograft Xenotech Laboratories, Inc., Irvine, CA; Gore-Tex, W. L. Gore and Associates, Flagstaff, AZ; and knitted dacron, Stryker, Kalamazoo, MI) and one ligament augmentation device (LAD, braided polypropylene, 3M, St. Paul, MN) were evaluated in vivo. The devices were placed unstressed, in an extraarticular location in the cortical-cancellous bone of the proximal femur and humerus of dogs. Six months following implantation tissue ingrowth was evaluated using high resolution radiography, routine histology, scanning electron microscopy, and biomechanical tensile tests to measure the ultimate (maximum) pull-out strength of the devices. The knitted dacron and Gore-Tex prosthesis showed marked ingrowth of trabecular bone into the interstices of the device with evidence of bone growth around individual fibers of the prosthesis. The bovine xenograft demonstrated bone immediately adjacent to the material with evidence of spicular ingrowth of bone into the natural clefts of the prosthesis. The LAD showed no evidence of bone ingrowth and demonstrated a fibrous tissue interface between the prosthesis and surrounding trabecular bone. Six months following implantation the pull-out strengths of the devices were as follows: knitted dacron, 445.7 +/- 151.0N; Gore-Tex, 438.1 +/- 131.94N; bovine xenograft, 332.8 +/- 64.2N; and LAD, 78.4 +/- 47.9N. Statistical analysis revealed no significant difference between the pull-out strengths of the knitted dacron, Gore-Tex, and bovine xenograft.(ABSTRACT TRUNCATED AT 250 WORDS)