title: Radiographic evaluation of a monoblock acetabular component: a multicenter study with 2- to 5-year results.
abstract: Serial radiographs of a porous tantalum monoblock acetabular cup design were evaluated for cup stability and signs of successful osteointegration. Of 574 primary consecutive total hip replacements in 542 patients performed by 9 surgeons at 7 hospitals, 414 cases were available for minimum 2-year follow-up. Follow-up averaged 33 months and ranged from 24 to 58 months. Postoperative radiographs revealed acetabular gaps in 100 zones in 80 (19%) hips: 29 in zone I, 67 in zone II, and 4 in zone III. At last follow-up, 84 (84%) of the zones with gaps completely filled in, and all 4- and 5-mm gaps filled in. There was no progression of any postoperative gap, no evidence of continuous periacetabular interface radiolucencies, no evidence of lysis, and no revisions for loosening. Although these short-term results are encouraging, further follow-up will be required to assess whether the monoblock design and the low modulus of elasticity of porous tantalum will reduce the incidence of periacetabular stress shielding and occurrence of osteolysis.
authors.affiliation: Zonal Concepts, Wesley Chapel, Florida, USA.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Gruen
authors.forename: Robert A
authors.initials: RA
authors.lastname: Poggie
authors.forename: David G
authors.initials: DG
authors.lastname: Lewallen
authors.forename: Arlen D
authors.initials: AD
authors.lastname: Hanssen
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Lewis
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: O'Keefe
authors.forename: S David
authors.initials: SD
authors.lastname: Stulberg
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Sutherland
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000293:injuries / Q000601:surgery*; D001696:Biomechanical Phenomena; D020099:Coated Materials, Biocompatible; D019544:Equipment Failure Analysis; D005500:Follow-Up Studies; D017102:Fracture Healing / Q000502:physiology; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000601:surgery; D006618:Hip Dislocation, Congenital / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D016348:Osseointegration / Q000502:physiology*; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging / Q000601:surgery; D010014:Osteolysis / Q000000981:diagnostic imaging; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011474:Prosthesis Design; D011859:Radiography; D013635:Tantalum; D014025:Titanium
chemical_list: D020099:Coated Materials, Biocompatible; D013635:Tantalum; D014025:Titanium