TY - JOUR
T1 - Effects of plate location and selection on the stability of midshaft clavicle osteotomies
T2 - A biomechanical study
AU - Iannotti, M. R.
AU - Crosby, L. A.
AU - Stafford, P.
AU - Grayson, Greg
AU - Goulet, R.
N1 - Funding Information:
Funding for this study was provided by the University of Tennessee Center for Excellence in Computer Applications in support of the UTC Biomechanics and Material Testing Laboratory, Chattanooga, Tenn.
PY - 2002/10
Y1 - 2002/10
N2 - Operative fixation of midshaft clavicle fractures is controversial with few biomechanical data to assist surgical decision making. The purpose of this 2-phase biomechanical investigation is to report on the effects of plate location and selection on the stability of midshaft clavicle fractures. Thirty matched pairs of human adult formalin-fixed clavicles were used. In the first phase, in which a 3.5-mm reconstruction plate and simulated midshaft transverse clavicle osteotomies were used, we observed the effect of superior plate placement compared with anterior placement on fracture rigidity, construct stiffness, and strength. In the second phase, in which simulated midshaft oblique clavicle osteotomies were repaired on the superior aspect, we compared the fracture rigidity, construct stiffness, and strength of the 3.5-mm reconstruction, 3.5-mm limited contact dynamic compression (LCDC), and 2.7-mm dynamic compression (DC) plates. Intact clavicles were prepared, potted, and tested for axial and torsional stiffness in an Instron test frame equipped with gimbaled fixtures. Clavicles were band-sawed to simulate an osteotomy, repaired, re-mounted on the test frame with shear and opening extensometers placed across the osteotomy site, and then tested to observe axial and torsional fracture rigidity and stiffness. Constructs were then loaded to failure in compression. First-order regressions were used to estimate fracture rigidity (in kilonewtons per millimeter)and retained construct stiffness (in kilonewtons per millimeter), whereas the maximum applied compressive load at collapse or gross deformation determined the failure load. Values for the comparisongroups were tested for significance at the 95% confidence level. In the first phase we found that constructs plated at the superior aspect of the clavicle exhibited significantly greater fracture rigidity and mean retained stiffness than the anterior location (P < .05). In the second phase we found that the torsional fracture rigidity of LCDC-plated constructs significantly exceeded that of the reconstruction and DC plates (P < .05), whereas the axial fracture rigidity of the LCDC-plated constructs significantly exceeded that of the reconstruction plate (P < .05). In retained stiffness the performance of the LCDC-plated constructs significantly exceeded that of the DC plate in torsion (P < .05), whereas in load to failure the LCDC plate withstood significantly more compressive load than the reconstruction plate (P < .05). We concluded that clavicles plated at the superior aspect exhibit significantly greater biomechanical stability than those plated at the anterior aspect. Furthermore, we concluded that the LCDC plate offers significantly greater biomechanical stability than the reconstruction and DC plates.
AB - Operative fixation of midshaft clavicle fractures is controversial with few biomechanical data to assist surgical decision making. The purpose of this 2-phase biomechanical investigation is to report on the effects of plate location and selection on the stability of midshaft clavicle fractures. Thirty matched pairs of human adult formalin-fixed clavicles were used. In the first phase, in which a 3.5-mm reconstruction plate and simulated midshaft transverse clavicle osteotomies were used, we observed the effect of superior plate placement compared with anterior placement on fracture rigidity, construct stiffness, and strength. In the second phase, in which simulated midshaft oblique clavicle osteotomies were repaired on the superior aspect, we compared the fracture rigidity, construct stiffness, and strength of the 3.5-mm reconstruction, 3.5-mm limited contact dynamic compression (LCDC), and 2.7-mm dynamic compression (DC) plates. Intact clavicles were prepared, potted, and tested for axial and torsional stiffness in an Instron test frame equipped with gimbaled fixtures. Clavicles were band-sawed to simulate an osteotomy, repaired, re-mounted on the test frame with shear and opening extensometers placed across the osteotomy site, and then tested to observe axial and torsional fracture rigidity and stiffness. Constructs were then loaded to failure in compression. First-order regressions were used to estimate fracture rigidity (in kilonewtons per millimeter)and retained construct stiffness (in kilonewtons per millimeter), whereas the maximum applied compressive load at collapse or gross deformation determined the failure load. Values for the comparisongroups were tested for significance at the 95% confidence level. In the first phase we found that constructs plated at the superior aspect of the clavicle exhibited significantly greater fracture rigidity and mean retained stiffness than the anterior location (P < .05). In the second phase we found that the torsional fracture rigidity of LCDC-plated constructs significantly exceeded that of the reconstruction and DC plates (P < .05), whereas the axial fracture rigidity of the LCDC-plated constructs significantly exceeded that of the reconstruction plate (P < .05). In retained stiffness the performance of the LCDC-plated constructs significantly exceeded that of the DC plate in torsion (P < .05), whereas in load to failure the LCDC plate withstood significantly more compressive load than the reconstruction plate (P < .05). We concluded that clavicles plated at the superior aspect exhibit significantly greater biomechanical stability than those plated at the anterior aspect. Furthermore, we concluded that the LCDC plate offers significantly greater biomechanical stability than the reconstruction and DC plates.
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U2 - 10.1067/mse.2002.125805
DO - 10.1067/mse.2002.125805
M3 - Article
C2 - 12378164
AN - SCOPUS:0041346511
SN - 1058-2746
VL - 11
SP - 457
EP - 462
JO - Journal of Shoulder and Elbow Surgery
JF - Journal of Shoulder and Elbow Surgery
IS - 5
ER -