Jakob Hallbauer1, Kajetan Klos2, Sascha Rausch3, Andreas Gräfenstein4, Felix Wipf5, Claudia Beimel6, Gunther Hofmann7, Thomas Mückley4. 1. Department of Trauma, Hand and Reconstructive Surgery, Jena University Hospital, Jena, Germany. Electronic address: Jakob.Hallbauer@med.uni-jena.de. 2. Department of Foot and Ankle Surgery, St. Vincenz and Elisabeth Hospital Mainz, Germany. 3. Department of Trauma, Hand and Reconstructive Surgery, Jena University Hospital, Jena, Germany. 4. Department of Trauma, Hand and Reconstructive Surgery, HELIOS Clinical Centre, Erfurt, Germany. 5. Stryker Trauma AG, Selzach, Switzerland. 6. Stryker Trauma GmbH, Schönkirchen, Germany. 7. Department of Trauma, Hand and Reconstructive Surgery, Jena University Hospital, Jena, Germany; Department of Trauma and Reconstructive Surgery, BG Centres Bergmannstrost, Halle, Germany.
Abstract
BACKGROUND: Polyaxial locking plates are becoming popular for the fixation of distal fibula fractures. This study establishes how construct stiffness and plate loosening, measured as range of motion, differs between lateral and posterolateral plate location. METHODS: Seven matched pairs of cadaver fibulae were osteotomized in standardized fashion to produce a Weber type B distal fibula fracture. The fragments were fixated with an interfragmentary lag screw and polyaxial locking plates, with one fibula in each pair receiving a posterolateral anti-glide-plate, and the other a lateral neutralization-plate. In a biomechanical test, the bending and torsional stiffnesses of the constructs and the ranges of motion (ROM) were measured and subjected to a paired comparison. RESULTS: The laterally plated group had a higher median (interquartile range) bending stiffness (29.2 (19.7) N/mm) and a smaller range of motion (2.06 (1.99) mm) than the posterolaterally plated group (14.6 (20.6) N/mm, and 4.11 (3.28) mm, respectively); however, the results were not statistically significant (pbending=0.314; pROM=0.325). Similarly, the torsional stiffness did not differ significantly between the two groups (laterally plated: 426 (259) Nmm/°; posterolaterally plated: 248 (399) Nmm/°; ptorsion=0.900). The range of motion measurements between the two groups under torsional loading were also statistically insignificant (laterally plated: 8.88 (6.30) mm; posterolaterally plated: 15.34 (12.64) mm; pROM=0.900). CONCLUSION: In biomechanical cadaver-model tests of Weber type B fracture fixation with polyaxial locking plates, laterally plated constructs and posterolaterally plated constructs performed without significantly difference. Therefore, other considerations, such as access morbidity, associated injuries, patient anatomy, or surgeon's preference, may guide the choice of plating pattern. Further clinical studies will be needed for the establishment of definitive recommendations. CLINICAL RELEVANCE: Information on the behavior of polyaxial locking plates is relevant to surgeons performing internal fixation of distal fibula fractures.
BACKGROUND: Polyaxial locking plates are becoming popular for the fixation of distal fibula fractures. This study establishes how construct stiffness and plate loosening, measured as range of motion, differs between lateral and posterolateral plate location. METHODS: Seven matched pairs of cadaver fibulae were osteotomized in standardized fashion to produce a Weber type B distal fibula fracture. The fragments were fixated with an interfragmentary lag screw and polyaxial locking plates, with one fibula in each pair receiving a posterolateral anti-glide-plate, and the other a lateral neutralization-plate. In a biomechanical test, the bending and torsional stiffnesses of the constructs and the ranges of motion (ROM) were measured and subjected to a paired comparison. RESULTS: The laterally plated group had a higher median (interquartile range) bending stiffness (29.2 (19.7) N/mm) and a smaller range of motion (2.06 (1.99) mm) than the posterolaterally plated group (14.6 (20.6) N/mm, and 4.11 (3.28) mm, respectively); however, the results were not statistically significant (pbending=0.314; pROM=0.325). Similarly, the torsional stiffness did not differ significantly between the two groups (laterally plated: 426 (259) Nmm/°; posterolaterally plated: 248 (399) Nmm/°; ptorsion=0.900). The range of motion measurements between the two groups under torsional loading were also statistically insignificant (laterally plated: 8.88 (6.30) mm; posterolaterally plated: 15.34 (12.64) mm; pROM=0.900). CONCLUSION: In biomechanical cadaver-model tests of Weber type B fracture fixation with polyaxial locking plates, laterally plated constructs and posterolaterally plated constructs performed without significantly difference. Therefore, other considerations, such as access morbidity, associated injuries, patient anatomy, or surgeon's preference, may guide the choice of plating pattern. Further clinical studies will be needed for the establishment of definitive recommendations. CLINICAL RELEVANCE: Information on the behavior of polyaxial locking plates is relevant to surgeons performing internal fixation of distal fibula fractures.