title: Modular necks in primary hip arthroplasty without anatomical deformity: no clear benefit on restoration of hip geometry and dislocation rate. An exploratory study.
abstract: Modular necks were introduced in total hip arthroplasty (THA) to improve restoration of hip-geometry and reduce dislocation-rates. This presumed advantage was evaluated retrospectively for patients with arthritis in otherwise anatomically normal hips. Restoration of hip-geometry was assessed on preoperative and postoperative calibrated radiographs in 95 consecutive primary THAs with a modular neck design and compared with 95 match controlled THAs with a similar monoblock stem. No significant differences were seen in restoration of body moment arm, leg length and cupangle. Offset restoration revealed a borderline significant difference (P = 0.48) with higher values for the monoblock stem. In both groups 4 dislocations within one year were encountered. In this study modular necks did not reveal a clear benefit in restoring hip geometry and dislocation rate after straightforward THA.
authors.affiliation: Department of Orthopaedics, Rijnstate Hospital, Arnhem, The Netherlands.
authors.forename: Davey M J M
authors.initials: DM
authors.lastname: Gerhardt
authors.affiliation: Department of Orthopaedics, Rijnstate Hospital, Arnhem, The Netherlands.
authors.forename: Pepijn
authors.initials: P
authors.lastname: Bisseling
authors.affiliation: Department of Orthopaedics, Rijnstate Hospital, Arnhem, The Netherlands.
authors.forename: Enrico
authors.initials: E
authors.lastname: de Visser
authors.affiliation: Department of Orthopaedics, Rijnstate Hospital, Arnhem, The Netherlands.
authors.forename: Job L C
authors.initials: JL
authors.lastname: van Susante
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000379:methods*; D005260:Female; D005265:Femoral Neck Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D005272:Femur Neck / Q000000981:diagnostic imaging / Q000601:surgery; D006617:Hip Dislocation / Q000209:etiology*; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging / Q000601:surgery*; D011474:Prosthesis Design; D011859:Radiography; D012189:Retrospective Studies
keywords: hip geometry; modular stem; monoblock stem; radiographic evaluation; restoration -total hip arthroplasty