title: Arthroplasty of the distal radioulnar joint using a new ulnar head endoprosthesis: preliminary report.
abstract: OBJECTIVE
  To report our experience using a distal ulnar head endoprosthesis to treat painful disorders of the distal radioulnar joint (DRUJ) secondary to (1) instability and (2) arthrosis.
  
  
  METHODS
  Our experience with over 2 years of follow-up study consists of 19 wrists (17 patients). All patients presented complaining of pain and functional disability of the upper limb due to convergence instability or arthrosis of the DRUJ. The patients were studied prospectively. Thirteen patients had a total of 37 previous wrist or DRUJ surgical procedures. Standardized preoperative and postoperative assessments included a patient-reported pain score, a functional satisfaction score, forearm range of motion, grip strength as a percentage of that of the opposite limb, and clinical and radiographic examinations. The Mayo Wrist Score was calculated before surgery and at the last follow-up period.
  
  
  RESULTS
  Overall, pain scores decreased 50%, and functional satisfaction scores improved 3-fold. Average grip strength improved by 4 kg, or 16% from preoperative measurements. Forearm rotation was unchanged. All wrists were clinically stable on the latest follow-up examination. Two failures occurred early, at 7 and 14 months. Currently, all prostheses remain clinically and radiographically stable.
  
  
  CONCLUSIONS
  Implant arthroplasty of the distal ulna combined with an adequate soft-tissue repair is recommended to improve pain, function, and strength of the wrist and forearm. Prosthetic replacement of the distal ulna restored stability to the DRUJ in patients with partial or complete excision of the ulnar head or DRUJ arthrosis and corrected radioulnar impingement. Incidences of complications or revision surgery to date have been low. Larger clinical and radiographic assessments will be needed to determine the long-term success of distal ulna prosthetic replacement.
  
  
  METHODS
  Therapeutic IV.
authors.affiliation: Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA.
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Willis
authors.forename: Richard A
authors.initials: RA
authors.lastname: Berger
authors.forename: William P
authors.initials: WP
authors.lastname: Cooney
mesh_terms: D000328:Adult; D000368:Aged; D001168:Arthritis / Q000503:physiopathology / Q000601:surgery*; D019643:Arthroplasty, Replacement; D005260:Female; D005500:Follow-Up Studies; D018737:Hand Strength; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology / Q000601:surgery*; D007595:Joint Prosthesis; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D017060:Patient Satisfaction; D011446:Prospective Studies; D011474:Prosthesis Design; D016879:Salvage Therapy; D016896:Treatment Outcome; D014457:Ulna / Q000601:surgery*; D014955:Wrist Joint / Q000503:physiopathology / Q000601:surgery*