Article

In vitro biomechanical comparison of limited contat dynamic compression plate and locking compression plate.

College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
Veterinary and Comparative Orthopaedics and Traumatology (Impact Factor: 0.89). 02/2005; 18(4):220-6.
Source: PubMed

ABSTRACT

The locking compression plate (LCP) supports biological osteosynthesis by functioning as an internal fixator, rather than as a full or limited contact bone plate which must be adequately contoured and affixed directly to the bone for stable internal fixation of the fracture. In order to help justify the use of the LCP in our veterinary patients, in vitro biomechanical testing was performed comparing the LCP to the conventional limited contact dynamic compression plate (LC-DCP) in canine femurs. We hypothesized that the LCP construct would be at least as stiff under bending and torsional loads as the LC-DCP. The LCP and LC-DCP were applied over a 20-mm osteotomy gap to contralateroal bones within each pair of 14 femora. Non-destructive four-point bending and torsion, and cyclical testing in torsion were performed. The constructs were then loaded to failure in torsion. In medial-lateral and lateral-medial structural bending, significant differences were not found between the LCP and LC-DCP, however, at the gap, the LCP construct was stiffer than the LC-DCP in lateral-medial bending. Significant differences in behaviour over time were not noted between the plate designs during cyclical testing. When loading the constructs to failure in internal rotation, the LC-DCP failed at a significantly lower twist angle (P = .0024) than the LCP. Based on the similar performance with loading, the locking compression plate is a good alternative implant for unstable diaphyseal femoral fracture repair in dogs.

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    • "Thus, although this was not intentional, rotational stability was also tested in addition to axial stability. The deflection of the distal fragment, which has also been observed in clinical cases (Figure 6), underlined that the area of bone-screw interface of the distal fragment was the weakest element of the fixation [24,31]. Bicortical screws were used exclusively in the present study because they are recommended for osteosynthesis in weak or compromised bones [20]. "
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    ABSTRACT: Background To compare the biomechanical in-vitro characteristics of limited-contact dynamic compression plate (LC-DCP) and locking compression plate (LCP) constructs in an osteotomy gap model of femoral fracture in neonatal calves. Pairs of intact femurs from 10 calves that had died for reasons unrelated to the study were tested. A 7-hole LC-DCP with six 4.5 mm cortical screws was used in one femur and a 7-hole LCP with four 5.0 mm locking and two 4.5 mm cortical screws was used in the corresponding femur. The constructs were tested to failure by cyclic compression at a speed of 2 mm/s within six increasing force levels. Results The bone-thread interface was stripped in 21 of 80 cortical screws (26.3%) before a pre-set insertion torque of 3 Nm was achieved. Only 3 corresponding intact pairs of constructs could be statistically compared for relative structural stiffness, actuator excursion and width of the osteotomy gap. Relative structural stiffness was significantly greater, actuator excursion and width of the osteotomy gap were significantly smaller in the LCP constructs. While failure occurred by loosening of the screws in the LC-DCP constructs, locking constructs failed by cutting large holes in the soft distal metaphyseal bone. Conclusions An insertion torque sufficient to provide adequate stability in femurs of newborn calves could not be achieved reliably with 4.5 mm cortical screws. Another limiting factor for both constructs was the weak cancellous bone of the distal fracture fragment. LCP constructs were significantly more resistant to compression than LC-DCP constructs.
    Full-text · Article · Aug 2012 · BMC Veterinary Research
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    • "interface was independent of bone mineral density (Fig. 15). Aguila et al. (2005) performed a comparison study between the LCP and LC-DCP using canine femurs loaded in four-point bending and torsion or cyclic loading in torsion . On the whole, there were no significant differences in bending between the LCP and LC-DCP. "
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    ABSTRACT: Open reduction and internal fixation of fractures involves the use of metallic implants to support bone reduction. This procedure is often used in situations in which adequate alignment and stability of the bone cannot be achieved using nonsurgical methods such as casting. The locking compression plate is a contemporary implant that allows for both conventional screw placement (using nonlocking screws) and locking screw placement (where screw heads lock into the plate at a predetermined angle). This allows for greater versatility in the application of internal fixation. This article presents a general overview of locking compression plate application along with a review of the locking compression plate literature.
    Full-text · Article · Feb 2008 · Journal of surgical orthopaedic advances
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    • "interface was independent of bone mineral density (Fig. 15). Aguila et al. (2005) performed a comparison study between the LCP and LC-DCP using canine femurs loaded in four-point bending and torsion or cyclic loading in torsion . On the whole, there were no significant differences in bending between the LCP and LC-DCP. "
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    ABSTRACT: Metallic implants are often involved in the open reduction and internal fixation of fractures. Open reduction and internal fixation is commonly used in cases of trauma when the bone cannot be healed using external methods such as casting. The locking compression plate combines the conventional screw hole, which uses non-locking screws, with a locking screw hole, which uses locking head screws. This allows for more versatility in the application of the plate. There are many factors which affect the functionality of the plate (e.g., screw placement, screw choice, length of plate, distance from bone, etc.). This paper presents a review of the literature related to the biomechanics of locking compression plates and their use as internal fixators in fracture healing. Furthermore, this paper also addresses the materials used for locking compression plates and their mechanical behavior, parameters that control the overall success, as well as inherent bone quality results.
    Full-text · Article · Jan 2008 · Clinical Biomechanics
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