BACKGROUND: Displaced medial malleolus fractures require surgical repair because of the critical role the structure plays in normal joint function. Various approaches exist, but options are limited for small fragment fractures. This study compared repair with the Medial Malleolar Sled fixation system (Trimed, Inc, Valencia, CA) to lag screws in 2 modes of biomechanical loading in a cadaveric model. METHODS: A Müller type B medial malleolus fracture was simulated on matched pairs of cadaveric lower extremities and repaired with the sled or 2 cancellous lag screws. Tibial distraction (tension, n = 10) or internal rotation (torsion, n = 11) was applied. Fragment movement was measured in the sagittal (tension and torsion) and transverse (torsion-only) planes. Fragment movement at 1 mm and 2 mm (clinical malunion) of gapping during tension and at 2, 4, 6, and 8 N-m during torsion was analyzed via paired t tests. RESULTS: In tension, the load at the 2-mm gap was statistically lower for screws (P = .026). Opening angle was statistically larger for the sled at the 1-mm (P = .0004) and 2-mm (P = .008) gap. In torsion, gapping was statistically lower for the sled (ranging from P = .0013 at 4 N-m to P = .0187 at 8 N-m). No differences were detected for opening angle or transverse plane movement. CONCLUSION: The sled appeared stronger in tension and as effective as lag screws in torsion. The sled may be a viable option for fractures too small for 4.0- or 3.5-mm lag screws. CLINICAL RELEVANCE: The sled may be suitable in applications where a tension band would normally be considered and may provide stronger fixation in osteoporotic bone compared with lag screw fixation.
BACKGROUND: Displaced medial malleolus fractures require surgical repair because of the critical role the structure plays in normal joint function. Various approaches exist, but options are limited for small fragment fractures. This study compared repair with the Medial Malleolar Sled fixation system (Trimed, Inc, Valencia, CA) to lag screws in 2 modes of biomechanical loading in a cadaveric model. METHODS: A Müller type B medial malleolus fracture was simulated on matched pairs of cadaveric lower extremities and repaired with the sled or 2 cancellous lag screws. Tibial distraction (tension, n = 10) or internal rotation (torsion, n = 11) was applied. Fragment movement was measured in the sagittal (tension and torsion) and transverse (torsion-only) planes. Fragment movement at 1 mm and 2 mm (clinical malunion) of gapping during tension and at 2, 4, 6, and 8 N-m during torsion was analyzed via paired t tests. RESULTS: In tension, the load at the 2-mm gap was statistically lower for screws (P = .026). Opening angle was statistically larger for the sled at the 1-mm (P = .0004) and 2-mm (P = .008) gap. In torsion, gapping was statistically lower for the sled (ranging from P = .0013 at 4 N-m to P = .0187 at 8 N-m). No differences were detected for opening angle or transverse plane movement. CONCLUSION: The sled appeared stronger in tension and as effective as lag screws in torsion. The sled may be a viable option for fractures too small for 4.0- or 3.5-mm lag screws. CLINICAL RELEVANCE: The sled may be suitable in applications where a tension band would normally be considered and may provide stronger fixation in osteoporotic bone compared with lag screw fixation.
Authors: Michael W Downey; Kyle Duncan; Victor Kosmopoulos; Travis A Motley; Brian B Carpenter; Fadeke Ogunyankin; Alan Garrett Journal: Scientifica (Cairo) Date: 2016-05-12
Authors: Ali Çağrı Tekin; Haluk Çabuk; Süleyman Semih Dedeoğlu; Mehmet Selçuk Saygılı; Müjdat Adaş; Cem Dinçay Büyükkurt; Hakan Gürbüz; Murat Çakar; Zeynep Nilüfer Tekin Journal: Med Princ Pract Date: 2016-06-07 Impact factor: 1.927