Poly-Methyil- Metacrylate does not provide significant reinforcement to a cadaveric diaphyseal model undergoing bending stress

Aim To test the consolidative properties of two different consolidative intra-medullary (IM) techniques (osteoplasty and Kirshener-augmented osteoplasty) in a diaphyseal cadaveric model undergoing three point bending test. Materiale and methods Thirty different human cadaveric tibia specimens were randomly and equally assigned to receive no IM consolidation (Group 1), osteoplasty (Group 2), or Kirshener-augmented osteoplasty (Group 3). All specimens were subsequently tested on a dedicated servohydraulic machine with a three-point bending test. Fracture load and Young's module were obtained for each tested specimen. In the end, fracture occurrence and its morphology both to bone and to IM consolidative material were evaluated. Results The median quantity of PMMA injected was 18 ml for group 2 (p25-p50; 15-21) and 19 ml for group 3 (p25-p50; 17-21). In terms of fracture load, no significant difference was found when comparing group 1 and 2 (z = -0.793; P = 0.4295), group 1 and 3 (z = -0.944; P = 0.3472), and group 2 and 3 (z = -0.454; P = 0.6501). Neither, Young's module differed significantly when comparing group 1 and 2 (z = 0.121; P = 0.9044), group 1 and 3 (z = 0.338; P = 0.7278), and group 2 and 3 (z = 0.148; P = 0.8807). The most common type of bone was B0 (14/30, 46.6%) and A2 (8/30, 26.6%). Fractures to the IM material occurred in 4 cases (4/30, 13.3%) and were always consistent with PMMA fracture. Conclusion PMMA does not confer any consolidative advantage to dyaphisis undergoing bending stresses as compared to non-PMMA augumented dyaphisys.