title: Joint-preserving surgical treatment of spontaneous osteonecrosis of the knee.
abstract: BACKGROUND
  To date, reports of surgical treatment of spontaneous osteonecrosis of the knee (SPONK) refractory to non-operative treatment have primarily focused on knee arthroplasty. This report presents an overview of the characteristics of SPONK and reports our experience with joint-preserving surgical treatment of this condition.
  
  
  METHODS
  Fifteen patients who had joint-preserving surgery after failed non-operative modalities were studied. These patients were treated at a single center between January 1998 and September 2006 with a combination of arthroscopy and core decompression, or osteochondral autograft transfers.
  
  
  RESULTS
  Thirteen of the 15 knees (87%) had knee joint survival with a mean Knee Society Score of 81 points (range 45–100 points) at a mean follow-up of 40 months (range 9–120 months). Five of seven knees treated with core decompression had a successful clinical outcome. One of the patients who failed core decompression later underwent osteochondral autograft transfer, and eight of nine knees treated with this modality had a successful outcome.
  
  
  CONCLUSIONS
  Overall, these results demonstrate that joint-preserving surgical treatment can successfully postpone the need for knee arthroplasty in selected patients with pre-collapse SPONK.
authors.affiliation: Department of Orthopaedic Surgery, Howard University Hospital, 2041 Georgia Avenue, Northwest, Washington, DC 20060, USA.
authors.forename: Nyagon G
authors.initials: NG
authors.lastname: Duany
authors.forename: Michael G
authors.initials: MG
authors.lastname: Zywiel
authors.forename: Mike S
authors.initials: MS
authors.lastname: McGrath
authors.forename: Junaed A
authors.initials: JA
authors.lastname: Siddiqui
authors.forename: Lynne C
authors.initials: LC
authors.lastname: Jones
authors.forename: Peter M
authors.initials: PM
authors.lastname: Bonutti
authors.forename: Michael A
authors.initials: MA
authors.lastname: Mont
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D001182:Arthroscopy / Q000379:methods*; D002356:Cartilage / Q000637:transplantation; D019902:Chondrocytes / Q000637:transplantation; D019299:Decompression, Surgical; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000473:pathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010020:Osteonecrosis / Q000601:surgery*; D015996:Survival Rate; D016896:Treatment Outcome