Abstract
The mechanical performance and the stress shielding effects of the Howmedica Spherolock MKII implant were evaluated. Three types of stable proximal femoral fractures were created in composite femurs and fixed with the nail-plate. The femurs were loaded to failure, and the yield strength, stiffness, and failure modes were noted. Additional intact composite femurs were fitted proximally with strain gauges, and the strain was examined under load. The femurs then underwent intertrochanteric fracture, plating, and re-testing. Comparative analysis showed that while the Spherolock system is less strong and stiff than other commonly used implants, it provides excellent and uniform load transfer across the fracture site. Varus rotation of the femoral head under load tended to open the fracture gap and localize the resultant load medially. Stress shielding of the calcar was less than 25% of the applied load even in the worst case. This very low stress shielding behavior was attributed mainly to the implant's low stiffness.
| Original language | English |
|---|---|
| Pages (from-to) | 137-142 |
| Number of pages | 6 |
| Journal | Archives of Orthopaedic and Trauma Surgery |
| Volume | 116 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 1997 |
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ASJC Scopus subject areas
- Surgery
- Orthopedics and Sports Medicine
Cite this
Biomechanical validation of a new nail-plate for the repair of stable proximal femoral fractures. / Ramer, M.; Viceconti, M.; Toni, A.; Pipino, F.; Giunti, A.
In: Archives of Orthopaedic and Trauma Surgery, Vol. 116, No. 3, 1997, p. 137-142.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Biomechanical validation of a new nail-plate for the repair of stable proximal femoral fractures
AU - Ramer, M.
AU - Viceconti, M.
AU - Toni, A.
AU - Pipino, F.
AU - Giunti, A.
PY - 1997
Y1 - 1997
N2 - The mechanical performance and the stress shielding effects of the Howmedica Spherolock MKII implant were evaluated. Three types of stable proximal femoral fractures were created in composite femurs and fixed with the nail-plate. The femurs were loaded to failure, and the yield strength, stiffness, and failure modes were noted. Additional intact composite femurs were fitted proximally with strain gauges, and the strain was examined under load. The femurs then underwent intertrochanteric fracture, plating, and re-testing. Comparative analysis showed that while the Spherolock system is less strong and stiff than other commonly used implants, it provides excellent and uniform load transfer across the fracture site. Varus rotation of the femoral head under load tended to open the fracture gap and localize the resultant load medially. Stress shielding of the calcar was less than 25% of the applied load even in the worst case. This very low stress shielding behavior was attributed mainly to the implant's low stiffness.
AB - The mechanical performance and the stress shielding effects of the Howmedica Spherolock MKII implant were evaluated. Three types of stable proximal femoral fractures were created in composite femurs and fixed with the nail-plate. The femurs were loaded to failure, and the yield strength, stiffness, and failure modes were noted. Additional intact composite femurs were fitted proximally with strain gauges, and the strain was examined under load. The femurs then underwent intertrochanteric fracture, plating, and re-testing. Comparative analysis showed that while the Spherolock system is less strong and stiff than other commonly used implants, it provides excellent and uniform load transfer across the fracture site. Varus rotation of the femoral head under load tended to open the fracture gap and localize the resultant load medially. Stress shielding of the calcar was less than 25% of the applied load even in the worst case. This very low stress shielding behavior was attributed mainly to the implant's low stiffness.
UR - http://www.scopus.com/inward/record.url?scp=0031045612&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031045612&partnerID=8YFLogxK
U2 - 10.1007/s004020050088
DO - 10.1007/s004020050088
M3 - Article
C2 - 9061168
AN - SCOPUS:0031045612
VL - 116
SP - 137
EP - 142
JO - Archiv fur orthopadische und Unfall-Chirurgie
JF - Archiv fur orthopadische und Unfall-Chirurgie
SN - 0936-8051
IS - 3
ER -