title: The minimal invasive direct anterior approach in combination with large heads in total hip arthroplasty - is dislocation still a major issue? a case control study.
abstract: BACKGROUND
  There have been increasing numbers of publications in recent years on minimally invasive surgery (MIS) for total hip arthroplasty (THA), reporting results with the use of different head sizes, tribologic and functional outcomes. This study presents the results and early complication rates after THA using the direct anterior approach (DAA) in combination with head sizes ≥ 36 mm.
  
  
  METHODS
  A total of 113 patients with THA were included in the study. The Harris Hip Score (HHS) was determined, a radiographic evaluation was carried out, and complications were recorded. The minimum follow-up period was 2 years (means 35 ± 7 months).
  
  
  RESULTS
  The HHS improved from 43.6 (± 12) to 88.2 (± 14; P < 0.01). One early infection occurred, one periprosthetic fracture, and three cases of aseptic stem loosening. No incorrect positioning of the implants was observed, and there were no dislocations.
  
  
  CONCLUSIONS
  THA with the minimally invasive DAA in combination with large heads is associated with good to very good functional results in the majority of cases. The complication rates are not increased. The rate of dislocation mainly as an complication of the first two years can be markedly reduced in particular.
authors.affiliation: Center of arthroplasty and revision arthroplasty, Department of General Orthopedics and Tumor Orthopedics, University Hospital Muenster, 48149 Muenster, Germany. steffen.hoell@ukmuenster.de.
authors.forename: Steffen
authors.initials: S
authors.lastname: Hoell
authors.forename: Marius
authors.initials: M
authors.lastname: Sander
authors.forename: Georg
authors.initials: G
authors.lastname: Gosheger
authors.forename: Helmut
authors.initials: H
authors.lastname: Ahrens
authors.forename: Ralf
authors.initials: R
authors.lastname: Dieckmann
authors.forename: Gregor
authors.initials: G
authors.lastname: Hauschild
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006617:Hip Dislocation / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging / Q000601:surgery; D010014:Osteolysis / Q000453:epidemiology; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012189:Retrospective Studies; D013530:Surgical Wound Infection / Q000453:epidemiology; D016896:Treatment Outcome; D055815:Young Adult