title: Influence of stem type on material loss at the metal-on-metal pinnacle taper junction.
abstract: The clinical importance of material loss at the head-stem junction is unknown. Comparison of retrievals with different stem types can provide the opportunity to understand the importance of the taper junction. This was a case-control study involving 20 retrieved 36 mm metal-on-metal Pinnacle (DePuy) hips that were paired with either a Corail (n = 10) or S-ROM (n = 10) stem. The median head taper material loss rate for the Corail group was 0.238 (0.0002-2.178) mm(3)/year and was significantly greater than the S-ROM group (p = 0.042), which had a median material loss rate of 0.132 (0.015-0.518) mm(3)/year. The only significant difference between the groups was the stem taper roughness and length: this was rougher and shorter for the Corails. Long and smooth stem taper designs are preferred when used in conjunction with metal heads.
authors: Institute of Orthopaedics and Musculoskeletal Science, University College London and Royal National Orthopaedic Hospital, Stanmore, UK h.hothi@ucl.ac.uk.
authors: Harry S
authors: HS
authors: Hothi
authors: Institute of Orthopaedics and Musculoskeletal Science, University College London and Royal National Orthopaedic Hospital, Stanmore, UK.
authors: Robert K
authors: RK
authors: Whittaker
authors: Institute of Orthopaedics and Musculoskeletal Science, University College London and Royal National Orthopaedic Hospital, Stanmore, UK.
authors: Jay M
authors: JM
authors: Meswania
authors: Institute of Orthopaedics and Musculoskeletal Science, University College London and Royal National Orthopaedic Hospital, Stanmore, UK.
authors: Gordon W
authors: GW
authors: Blunn
authors: Institute of Orthopaedics and Musculoskeletal Science, University College London and Royal National Orthopaedic Hospital, Stanmore, UK.
authors: John A
authors: JA
authors: Skinner
authors: Institute of Orthopaedics and Musculoskeletal Science, University College London and Royal National Orthopaedic Hospital, Stanmore, UK.
authors: Alister J
authors: AJ
authors: Hart
mesh_terms: D000328:Adult; D000368:Aged; D019544:Equipment Failure Analysis; D005260:Female; D017276:Friction; D006622:Hip Prosthesis; D006801:Humans; D061825:Metal-on-Metal Joint Prostheses; D008670:Metals / Q000737:chemistry*; D008875:Middle Aged; D010316:Particle Size; D011474:Prosthesis Design; D013499:Surface Properties
chemical_list: D008670:Metals
keywords: Wear analysis/testing; biomedical devices; hip prostheses; medical biomaterials; orthopaedic tribology