Principle and stability of locking plates

Abstract

A new internal Mini-Locking-System was tested compared with conventional 2.0mm Mini plates. Standardised osteotomies in the angular region of 16 human cadaver mandibles were fixed with a 6-hole-plate at the oblique line. Osteosynthesis and stability of fixation was proofed in a three dimensional in-vitro-model in which functional load was simulated. Comparison of the different osteosynthesis techniques showed that in the case of Miniplate fixation torsion and gapping of the bone fragments occurred following plate application and screw tightening when the plates were pressed onto the bone, so last incongruences between bone surface and plate were transferred to the mobile bone fragments resulting in more extended gaps and torsion. This was only observed to a much lesser extent with the Mini-Locking-System due to the fixation principle avoiding pressure to the bone. During functional loading the Mini-Locking-System showed also a significant higher stability in comparison to conventional Miniplates. Due to the fixation method imitating the principles of a fixateur the screws form together with the plate and the cortical bone a frame construction. Loading forces are transmitted without the need of plate friction directly from bone over the screws to the plate resulting in higher

Standard 3D Titanium Miniplate Versus Locking 3D Miniplate in Fracture of Mandible: A Prospective Comparative Study

“…Gutwald et al [20] and Pektas et al [21] in a cadaveric study comparing mini-locking system with conventional miniplates, subjected to mechanical loading simulating muscle forces showed the lowest gaps and torsion, best stability at the caudal border in case of mini locking plates. Authors stated that the locking principle prevents stripping, movement and loosening of screws.…”

“…They concluded that the possible advantage of locking plate/screw fixation system are theoretical, whether clinical results can be improved could not be measured. Gutwald et al [20] experienced complications in the region of angle followed by parasymphysis and body. Minor infections required hardware removal, and occlusal discrepancy was treated with elastics and enameloplasty.…”

Three-dimensional Finite Element Analysis of Bone Fixation in Bilateral Sagittal Split Ramus Osteotomy Using Individual Models

“…The biomechanical properties of locking and conventional titanium systems were evaluated by Gutwald et al 7) and Ellis et al 4) . Both were clinical reports and presented positive results, but were conducted on mandibular fracture patterns.…”

Study of Efficacy and the Comparison Between 2.0 mm Locking Plating System and 2.0 mm Standard Plating System in Mandibular Fractures

“…Exact plate adaptation is no longer necessary which should shorten operation times [32][33][34]. The operating time required for the adaptation and fixation of locking plate ranged from 5 to 9 min with a mean time of 6.8 min and the operating time required for the adaptation and fixation of Champy's miniplate ranges from 8 to 14 min with a mean of 10.1 min.…”