title: Pyrocarbon interposition shoulder arthroplasty: preliminary results from a prospective multicenter study at 2 years of follow-up.
abstract: BACKGROUND
  The concept of free interposition arthroplasty proved successful for small joints of the hand, wrist, and foot, particularly after the use of implants coated with pyrocarbon, which enhanced their tribologic and elastic properties. The present study reports preliminary outcomes of a pyrocarbon-coated interposition shoulder arthroplasty (PISA) implant.
  
  
  METHODS
  This was a prospective study of 67 consecutive patients who underwent shoulder PISA at 9 centers. The mean age at surgery was 51 years, with only 12 patients older than 60 years. The indications for surgery were primary glenohumeral arthritis in 42, avascular necrosis in 13, and secondary arthritis in 12 patients.
  
  
  RESULTS
  Revision surgery was performed in 7 patients (10.4%), 2 (3.0%) were lost to follow-up, and the outcome assessments were incomplete in 3 (4.4%). This left 55 patients, aged 49.3 ± 12.0 years, with complete outcomes assessments at a mean follow-up of 26.8 ± 3.4 months. The Constant score improved from 34.1 ± 15.1 preoperatively to 66.1 ± 19.7 postoperatively. The radiographic findings revealed erosion in 6 glenoids and thinning of 3 humeral tuberosities.
  
  
  CONCLUSIONS
  In a cohort of young arthritic patients, PISA renders clinical scores and implant survival comparable to those of hemishoulder arthroplasty but remain inferior to those results reported for total shoulder arthroplasty. The study enabled identification of contraindications and potential causes of failure that wererelated to the concept of free interposition and smaller radius of curvature of the sphere. Until long-term results are available, this type of innovative implant should remain to be tested in a few specialized shoulder centers.
authors.affiliation: Clinique du Parc, Lyon, France. Electronic address: j.garret@cliniqueduparclyon.com.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Garret
authors.affiliation: Centre Orthopédique Santy, Lyon, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Godeneche
authors.affiliation: Institut Universitaire de Locomotion et du Sport, Hôpital Pasteur 2, Nice, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Boileau
authors.affiliation: Centre Chirurgical Emile Gallé, Nancy, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Molé
authors.affiliation: Sjukhuset, Varberg, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Etzner
authors.affiliation: Service de Chirurgie Orthopédique, Hôpital Trousseau, Tours, France.
authors.forename: Luc
authors.initials: L
authors.lastname: Favard
authors.affiliation: Clinique du Parc, Lyon, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Levigne
authors.affiliation: Centre Chirurgical Emile Gallé, Nancy, France.
authors.forename: François
authors.initials: F
authors.lastname: Sirveaux
authors.affiliation: Institut Universitaire de Locomotion et du Sport, Hôpital Pasteur 2, Nice, France.
authors.forename: Marc-Olivier
authors.initials: MO
authors.lastname: Gauci
authors.affiliation: Centre Chirurgical Emile Gallé, Nancy, France.
authors.forename: Charles
authors.initials: C
authors.lastname: Dezaly
authors.affiliation: Centre Orthopédique Santy, Lyon, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Walch
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000072228:Arthroplasty, Replacement, Shoulder / Q000295:instrumentation*; D001672:Biocompatible Materials; D002244:Carbon; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007592:Joint Diseases / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011474:Prosthesis Design; D012086:Reoperation; D012785:Shoulder Joint; D000072227:Shoulder Prosthesis; D055815:Young Adult
chemical_list: D001672:Biocompatible Materials; C009139:pyrolytic carbon; D002244:Carbon
keywords: Glenohumeral arthritis; interposition arthroplasty; osteoarthritis; pyrocarbon; pyrolytic carbon; shoulder arthroplasty