title: Hip chondrolysis and femoral head osteonecrosis: a complication of periacetabular cryoablation.
abstract: OBJECTIVE
  To describe a new complication and retrospectively identify the incidence and risk factors for hip chondrolysis and femoral head osteonecrosis associated with percutaneous cryoablation of periacetabular malignancies.
  
  
  METHODS
  In this retrospective study, 45 patients with a total of 113 musculoskeletal lesions were treated by percutaneous image-guided cryoablation between May 2008 and June 2013. Included in the treated population were 10 patients with a total of 12 periacetabular lesions. Clinical and imaging follow-up of at least 2 months was reviewed for evidence of femoral head osteonecrosis or hip chondrolysis. Parametric and nonparametric statistical methods were used to assess patient demographics and treatment technique and parameters on the development of hip chondrolysis/femoral head osteonecrosis.
  
  
  RESULTS
  Hip chondrolysis/femoral head osteonecrosis developed in 40% of patients (four of 10) and in 33% of treated periacetabular lesions (four of 12). All patients in whom chondrolysis/osteonecrosis developed were women. Needle proximity to the acetabulum (< 5 mm) was a significant predictor of chondrolysis/osteonecrosis development (P = .01). Three of the four patients in whom chondrolysis/osteonecrosis developed have undergone total joint replacement.
  
  
  CONCLUSIONS
  Periacetabular cryoablation can result in transarticular extension of the ablation zone, which may result in the development of hip chondrolysis and femoral head osteonecrosis. The proximity of the cryoablation probe to the acetabulum is a significant risk factor in the development of this complication.
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S. Kingshighway Blvd., St. Louis, MO 63110. Electronic address: friedmanm@mir.wustl.edu.
authors.forename: Michael V
authors.initials: MV
authors.lastname: Friedman
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S. Kingshighway Blvd., St. Louis, MO 63110.
authors.forename: Travis J
authors.initials: TJ
authors.lastname: Hillen
authors.affiliation: Department of Radiology, Mayo Clinic, Jacksonville, Florida.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Wessell
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S. Kingshighway Blvd., St. Louis, MO 63110.
authors.forename: Charles F
authors.initials: CF
authors.lastname: Hildebolt
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S. Kingshighway Blvd., St. Louis, MO 63110.
authors.forename: Jack W
authors.initials: JW
authors.lastname: Jennings
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D001859:Bone Neoplasms / Q000556:secondary / Q000601:surgery*; D002357:Cartilage Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D003452:Cryosurgery / Q000009:adverse effects*; D005260:Female; D005271:Femur Head Necrosis / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D006801:Humans; D015994:Incidence; D008279:Magnetic Resonance Imaging; D008297:Male; D059146:Metastasectomy / Q000009:adverse effects* / Q000379:methods; D008875:Middle Aged; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult