Trunnion-Head Stresses in THA: Are Big Heads Trouble?
The effects of large heads on stresses at the THA trunnion-head junction and their impact on tribocorrosion/metal ion release remain controversial. A 12/14 3D-model of a stem with different head sizes was investigated. Material properties of titanium were assigned to the trunnion and cobalt-chrome/alumina to the heads. A load simulating walking single-leg stand phase was applied to the head. A total contact head-trunnion interface was assumed. The area underneath the junction underwent significant elevations in stresses as head size increased from 28- to 40-mm. Maximum principal stress doubled between 28 and 40-mm heads, regardless of head material. Stress levels had a direct correlation to head diameter. Stress increases observed using increasingly larger heads will probably contribute to head-trunnion tribocorrosion and ion release.
The Center for Advanced Orthopedics at Larkin Hospital, South Miami, Florida.
Carlos J
CJ
Lavernia
The Center for Advanced Orthopedics at Larkin Hospital, South Miami, Florida; Arthritis Surgery Research Foundation, South Miami, Florida.
David A
DA
Iacobelli
The Center for Advanced Orthopedics at Larkin Hospital, South Miami, Florida; Arthritis Surgery Research Foundation, South Miami, Florida.
Jesus M
JM
Villa
Amoeba Technologies, Inc., Ft. Lauderdale, Florida.
Kinzy
K
Jones
Florida International University Mechanical and Materials Engineering, Miami, Florida.
Jose L
JL
Gonzalez
Florida International University Mechanical and Materials Engineering, Miami, Florida.
William Kinzy
WK
Jones
D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation* / Q000379:methods*; D002858:Chromium Alloys; D005270:Femur Head / Q000601:surgery; D020342:Finite Element Analysis; D006622:Hip Prosthesis; D006801:Humans; D007477:Ions; D011474:Prosthesis Design; D013314:Stress, Mechanical; D013718:Tensile Strength; D014025:Titanium
D002858:Chromium Alloys; D007477:Ions; D014025:Titanium
Morse taper; corrosion; finite element analysis; large diameter head; total hip arthroplasty; trunnion