title: Small stem total hip arthroplasty in hypoplasia of the femur.
abstract: Total hip arthroplasty in hypoplastic femurs is technically difficult and the incidence of complications and aseptic loosening is relatively high. Cemented, uncemented, off-the-shelf, and custom-made stems all have been advocated in these cases. From 1978 to 1997, we performed 86 total hip arthroplasties in 77 patients with a hypoplastic femur using a cemented, off-the-shelf, small, curved, cobalt-chromium stem. We hypothesized results equaled those of the identical but larger-sized stems in normal-sized femora which were used as comparisons. Clinical and radiographic evaluations were performed. Minimum followup was 4.2 years (mean, 12 years; range, 4.2-20.3 years); mean Harris hip score was 88, and mean hip flexion was 104 degrees . Six stems were revised: four because of aseptic loosening, one after a femoral fracture, and one because of malpositioning. Complications included one perforation and one fracture of the femur, one fracture, one nonunion of the greater trochanter, and one deep infection. Implant survivorship for all hips at 15 years with aseptic revision of the stem as the end point was 90% (confidence interval, 82-99) which equaled results of the larger stems. The small off-the-shelf cemented Weber stem has a high long-term survival and a low complication rate. Survival compares favorably with other small-sized total hip systems.
  
  
  METHODS
  Level III, therapeutic study, case-control.
authors.affiliation: Department of Orthopaedic Surgery, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands. harald.deman@gmail.com
authors.forename: F Harald R
authors.initials: FH
authors.lastname: De Man
authors.forename: Daniel
authors.initials: D
authors.lastname: Haverkamp
authors.forename: Harm M
authors.initials: HM
authors.lastname: Van der Vis
authors.forename: Philip P
authors.initials: PP
authors.lastname: Besselaar
authors.forename: René K
authors.initials: RK
authors.lastname: Marti
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D015331:Cohort Studies; D005260:Female; D005269:Femur / Q000473:pathology*; D006621:Hip Joint; D006622:Hip Prosthesis; D006801:Humans; D007592:Joint Diseases / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011859:Radiography; D012189:Retrospective Studies; D016896:Treatment Outcome