Fixation of patella fractures with braided polyester suture: a biomechanical study

Abstract

We tested the quality of fixation of displaced transverse patella fractures using braided polyester suture to investigate the suitability of this material as an alternative to stainless steel wire for fixation of these fractures. Osteotomies were created to simulate fractures of the patella in ten cadaveric knee specimens and were sequentially fixed using two techniques: the modified tension-band technique and the longitudinal anterior band (Lotke) technique. Each technique was implemented using either 1.25-mm stainless steel wire or 7-metric braided polyester suture (No. 5 Ethibond). The quality of fixation for each technique was tested by measuring the fracture gap during three simulated extensions of the knee against gravity on a materials testing machine. All techniques behaved comparably under the loading conditions used. In the four groups, there was no fixation failure (fracture gap >3 mm) nor any significant difference between the mean maximum fracture gaps. The quality of fixation for braided polyester suture was comparable to that of stainless steel wire for such fractures, providing sufficient stability to withstand loads likely to be encountered during postoperative rehabilitation. Our results support the use of braided polyester suture as an alternative to stainless steel wire for fixation of displaced patella fractures.