title: Jumbo femoral head for the treatment of recurrent dislocation following total hip replacement.
abstract: BACKGROUND
  The purpose of this study was to assess the results of the use of a jumbo femoral head to restore stability in hips that had sustained recurrent dislocations after total hip replacement.
  
  
  METHODS
  Twelve hips in twelve patients who had had multiple hip operations and recurrent instability of the hip underwent a total hip replacement with use of a femoral head with an average diameter of 44 mm (range, 40 to 50 mm). The average age of the patients was fifty-nine years (range, twenty-nine to eighty-four years). The twelve patients had had an average of four previous operations (range, one to eight operations) and seven dislocations (range, two to twenty dislocations). A bipolar head was used in ten hips that had a femoral stem with a fixed (non-modular) head, and a modular head (unipolar) was used in two hips. (One hip was first treated with a bipolar head and then with a unipolar head.)
  
  
  RESULTS
  One patient died of unrelated causes fourteen months postoperatively. The hip had remained stable until the time of death. After an average duration of follow-up of 6.5 years (range, 3.2 to 11.8 years), ten of the remaining eleven hips had had no additional episodes of instability. One hip dislocated within one week after the revision, necessitating revision surgery to reposition the acetabular component. This hip was found to be stable at the time of follow-up 7.6 years after the revision. There were four other reoperations: one was done because of a fracture of the polyethylene; one, because of entrapment of cement within the articulation; one, because of pain related to loosening of the femoral stem; and one, because of late hematogenous infection. The preoperative and postoperative University of California at Los Angeles hip scores for the series were, respectively, 7 and 9 points for pain, 5 and 7 points for walking, 4 and 6 points for function, and 3 and 5 points for activity.
  
  
  CONCLUSIONS
  A jumbo-diameter femoral head provided stability and improved function without compromising range of motion in patients with recurrent dislocations following total hip arthroplasty.
authors.affiliation: Joint Replacement Institute at Orthopaedic Hospital, Los Angeles, California 90007, USA.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Beaulé
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Schmalzried
authors.forename: Pacharapol
authors.initials: P
authors.lastname: Udomkiat
authors.forename: Harlan C
authors.initials: HC
authors.lastname: Amstutz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D005270:Femur Head; D006617:Hip Dislocation / Q000209:etiology / Q000601:surgery*; D006801:Humans; D008875:Middle Aged; D011183:Postoperative Complications; D011474:Prosthesis Design; D012008:Recurrence; D012086:Reoperation