Abstract
OBJECTIVES: Lateral locked plating for proximal tibial fractures with metaphyseal disruption provides a biomechanically stable and biologically favorable alternative to conventional medial/lateral plate fixation. New polyaxial screw technology incorporates expanding screw bushings, allowing variable angle screw placement, while providing angular stability. We hypothesize that polyaxial locking plates will exhibit comparable stiffness, strength to failure, and resistance to plastic deformation to conventional locking plates in a proximal tibial gap model. METHODS: We stabilized extra-articular metaphyseal gap osteotomies in synthetic composite tibiae with dual medial and lateral plating, Less Invasive Stabilization System (LISS) plates, 4.5-mm proximal tibial lateral locking plates with (LP+) and without (LP-) angled screws, and 4.5-mm polyaxial locking plates with (PA+) and without (PA-) angled screws. All were tested with cyclic, ramped, and axial loading to failure. RESULTS: No plates demonstrated screw failure before plate failure. Dual-plate constructs did not fail. All lateral plates failed at the osteotomy. LP- failed at low load. PA+ was significantly stiffer (165 ± 17 N/mm) with greater load to failure (711 ± 23 N) than all other constructs (PA-: 56 ± 6 N/mm, 617 ± 33 N; LP+: 137 ± 23 N/mm, 488 ± 39 N; LISS: 76 ± 5 N/mm, 656 ± 39 N). PA+ had significantly less plastic deformation (12.1 ± 0.8 mm) than LP+ (13.4 ± 3.7 mm), but more than PA- (5.8 ± 1.2 mm) and LISS (3.9 ± 0.6 mm). PA- did not differ significantly from LISS in any parameter. CONCLUSIONS: This study demonstrates that this unique polyaxial locking plate mechanism, when tested in various constructs, exhibits similar biomechanical performance regarding stiffness, strength to failure, and resistance to plastic deformation when compared with uniaxial locking plates. The polyaxial locking plate with an angled screw was stiffest and had the greatest load to failure. The polyaxial locking plate alone tested similar to the LISS. In addition, the benefit of the angled screw for biomechanical stability is demonstrated.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 507-513 |
| Number of pages | 7 |
| Journal | Journal of Orthopaedic Trauma |
| Volume | 23 |
| Issue number | 7 |
| DOIs | |
| State | Published - Aug 2009 |
Fingerprint
Keywords
- Biomechanics
- Locked plates
- Polyaxial fixation
- Proximal tibial fractures
- Tibia
ASJC Scopus subject areas
- Surgery
- Orthopedics and Sports Medicine
Cite this
Biomechanical comparison of polyaxial and uniaxial locking plate fixation in a proximal tibial gap model. / Cullen, Aaron B.; Curtiss, Shane; Lee, Mark A.
In: Journal of Orthopaedic Trauma, Vol. 23, No. 7, 08.2009, p. 507-513.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Biomechanical comparison of polyaxial and uniaxial locking plate fixation in a proximal tibial gap model
AU - Cullen, Aaron B.
AU - Curtiss, Shane
AU - Lee, Mark A
PY - 2009/8
Y1 - 2009/8
N2 - OBJECTIVES: Lateral locked plating for proximal tibial fractures with metaphyseal disruption provides a biomechanically stable and biologically favorable alternative to conventional medial/lateral plate fixation. New polyaxial screw technology incorporates expanding screw bushings, allowing variable angle screw placement, while providing angular stability. We hypothesize that polyaxial locking plates will exhibit comparable stiffness, strength to failure, and resistance to plastic deformation to conventional locking plates in a proximal tibial gap model. METHODS: We stabilized extra-articular metaphyseal gap osteotomies in synthetic composite tibiae with dual medial and lateral plating, Less Invasive Stabilization System (LISS) plates, 4.5-mm proximal tibial lateral locking plates with (LP+) and without (LP-) angled screws, and 4.5-mm polyaxial locking plates with (PA+) and without (PA-) angled screws. All were tested with cyclic, ramped, and axial loading to failure. RESULTS: No plates demonstrated screw failure before plate failure. Dual-plate constructs did not fail. All lateral plates failed at the osteotomy. LP- failed at low load. PA+ was significantly stiffer (165 ± 17 N/mm) with greater load to failure (711 ± 23 N) than all other constructs (PA-: 56 ± 6 N/mm, 617 ± 33 N; LP+: 137 ± 23 N/mm, 488 ± 39 N; LISS: 76 ± 5 N/mm, 656 ± 39 N). PA+ had significantly less plastic deformation (12.1 ± 0.8 mm) than LP+ (13.4 ± 3.7 mm), but more than PA- (5.8 ± 1.2 mm) and LISS (3.9 ± 0.6 mm). PA- did not differ significantly from LISS in any parameter. CONCLUSIONS: This study demonstrates that this unique polyaxial locking plate mechanism, when tested in various constructs, exhibits similar biomechanical performance regarding stiffness, strength to failure, and resistance to plastic deformation when compared with uniaxial locking plates. The polyaxial locking plate with an angled screw was stiffest and had the greatest load to failure. The polyaxial locking plate alone tested similar to the LISS. In addition, the benefit of the angled screw for biomechanical stability is demonstrated.
AB - OBJECTIVES: Lateral locked plating for proximal tibial fractures with metaphyseal disruption provides a biomechanically stable and biologically favorable alternative to conventional medial/lateral plate fixation. New polyaxial screw technology incorporates expanding screw bushings, allowing variable angle screw placement, while providing angular stability. We hypothesize that polyaxial locking plates will exhibit comparable stiffness, strength to failure, and resistance to plastic deformation to conventional locking plates in a proximal tibial gap model. METHODS: We stabilized extra-articular metaphyseal gap osteotomies in synthetic composite tibiae with dual medial and lateral plating, Less Invasive Stabilization System (LISS) plates, 4.5-mm proximal tibial lateral locking plates with (LP+) and without (LP-) angled screws, and 4.5-mm polyaxial locking plates with (PA+) and without (PA-) angled screws. All were tested with cyclic, ramped, and axial loading to failure. RESULTS: No plates demonstrated screw failure before plate failure. Dual-plate constructs did not fail. All lateral plates failed at the osteotomy. LP- failed at low load. PA+ was significantly stiffer (165 ± 17 N/mm) with greater load to failure (711 ± 23 N) than all other constructs (PA-: 56 ± 6 N/mm, 617 ± 33 N; LP+: 137 ± 23 N/mm, 488 ± 39 N; LISS: 76 ± 5 N/mm, 656 ± 39 N). PA+ had significantly less plastic deformation (12.1 ± 0.8 mm) than LP+ (13.4 ± 3.7 mm), but more than PA- (5.8 ± 1.2 mm) and LISS (3.9 ± 0.6 mm). PA- did not differ significantly from LISS in any parameter. CONCLUSIONS: This study demonstrates that this unique polyaxial locking plate mechanism, when tested in various constructs, exhibits similar biomechanical performance regarding stiffness, strength to failure, and resistance to plastic deformation when compared with uniaxial locking plates. The polyaxial locking plate with an angled screw was stiffest and had the greatest load to failure. The polyaxial locking plate alone tested similar to the LISS. In addition, the benefit of the angled screw for biomechanical stability is demonstrated.
KW - Biomechanics
KW - Locked plates
KW - Polyaxial fixation
KW - Proximal tibial fractures
KW - Tibia
UR - http://www.scopus.com/inward/record.url?scp=68949192319&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=68949192319&partnerID=8YFLogxK
U2 - 10.1097/QAI.0b013e3181a25368
DO - 10.1097/QAI.0b013e3181a25368
M3 - Article
C2 - 19633460
AN - SCOPUS:68949192319
VL - 23
SP - 507
EP - 513
JO - Journal of Orthopaedic Trauma
JF - Journal of Orthopaedic Trauma
SN - 0890-5339
IS - 7
ER -