Comparison of clinically used bilayer collagen membrane and trilayer collagen prototype fixation stability in chondral defects at the talus - An experimental human specimen study.

ABSTRACT

BACKGROUND: The purpose of this human specimen experimental study was to compare the fixation stability of clinically used bilayer collagen membrane with fibrin glue with trilayer collagen prototype without fibrin glue in chondral defects at the medial or lateral talar shoulder (both matrices from Geistlich Pharma AG, Wollhusen, Switzerland). METHODS: Eleven human specimens were used. The membranes were implanted in standardized chondral defects at the medial and lateral talar shoulder randomized. All tests were performed in load-control 15 kg. Range of motion ROM of each ankle was examined individually before testing. The average ROM was 10° dorsiflexion range 0°-20° and 30° plantarflexion range 20°-45°. 1,000 testing cycles with the defined ROM were performed. Two independent investigators, blinded to membrane and fixation type, visually assessed the membrane fixation integrity for peripheral detachment, area of defect uncovered, membrane constitution and delamination. RESULTS: The clinically used bilayer collagen membrane plus fibrin glue showed higher fixation stability than the trilayer prototype (all p < 0.05). No significant differences occurred between medial and lateral talar shoulder location (all p > 0.05). CONCLUSIONS: The fixation stability of the trilayer collagen prototype without fibrin glue is lower than of the clinically used bilayer membrane with fibrin glue in chondral defects at the medial and lateral talar shoulder in an experimental human specimen test. Clinical use of trilayer collagen prototype without fibrin glue has to be validated by clinical testing to evaluate if the lower stability of fixation is still sufficient.