title: Stable fixation of short-stem femoral implants in patients 70 years and older.
abstract: BACKGROUND
  Limitations of conventional uncemented femoral stems persist, including proximal-distal mismatch, nonideal load transfer, loss of bone, and difficulties with minimally invasive surgery. Metaphyseal-engaging short-stem implants have been designed to address these issues in THA. While these devices have been studied in younger patients, it is unclear whether they offer advantages in older patients.
  
  
  OBJECTIVE
  We asked whether the stability and bony ingrowth of an off-the-shelf short stem in patients 70 years and older were similar to those achieved in patients younger than 70 years at 2-year followup. Furthermore, we asked whether pain and function scores were affected by age, bone quality, or varus alignment.
  
  
  METHODS
  We retrospectively reviewed 60 patients (65 hips) 70 years and older (mean, 75 years; range, 70-86 years) treated with an uncemented short stem (range, 90-105 mm). We compared radiographic alignment, stability, and bony ingrowth, as well as Harris hip scores and WOMAC pain scores, to a cohort of 89 patients (91 hips) younger than 70 years. Minimum followup was 24 months (mean, 35 months; range, 24-60 months).
  
  
  RESULTS
  Radiographs showed proximal bony ingrowth and stable fixation of all implants. Average Harris hip score at last followup was 88 (range, 70-100) for the 70 years and older cohort and 93 (range, 70-100) for younger than 70 years cohort; no patients reported thigh pain. Postoperative WOMAC scores averaged 6 (range, 0-43) and 5 (range, 0-25), respectively.
  
  
  CONCLUSIONS
  Short-stem implants provide solid, dependable fixation in osteoporotic bone at minimum 2-year followup, while meeting some of the limitations in conventional primary THA.
  
  
  METHODS
  Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedic Surgery, Feinberg School of Medicine, Northwestern University, 401 E Ontario Street, Unit 1707, Chicago, IL 60611, USA. r-patel7@md.northwestern.edu
authors.forename: Ronak M
authors.initials: RM
authors.lastname: Patel
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Smith
authors.forename: Chase C
authors.initials: CC
authors.lastname: Woodward
authors.forename: S David
authors.initials: SD
authors.lastname: Stulberg
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D018771:Arthralgia / Q000209:etiology; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation*; D016009:Chi-Square Distribution; D002641:Chicago; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery*; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D007593:Joint Instability / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D016348:Osseointegration; D010024:Osteoporosis / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000209:etiology; D011474:Prosthesis Design; D011859:Radiography; D016059:Range of Motion, Articular; D020127:Recovery of Function; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome