title: Synovial fluid metabolites in osteonecrosis.
abstract: OBJECTIVE
  Osteonecrosis of the femoral head results from interruption of the vascular supply and eventual death of the cellular portion of bone. Effective methods of monitoring response to treatment are needed. Our aim was to evaluate synovial fluid metabolites, glucose and lactate, as biomarkers in a canine model of osteonecrosis.
  
  
  METHODS
  Osteonecrosis was cryosurgically induced in the right femoral head while the left hip served as control (n = 31). Animals either underwent no further intervention (n = 10), vascular endothelial growth factor (VEGF) injections (n = 4), placement of a vascularized bone graft (n = 6), a combination of VEGF microinjection and vascularized graft placement (n = 5), or treatment with daily oral alendronate (n = 6). After 12 weeks, synovial fluid from each hip joint was obtained for glucose and lactate concentrations.
  
  
  RESULTS
  Joints with surgically induced osteonecrosis demonstrated decreased synovial fluid concentrations of glucose (P < 0.05) and elevated concentrations of lactate (P < 0.05) relative to contralateral control hips. When animals were treated with VEGF, the vascularized graft placement, or vascularized graft and VEGF, there were no differences in the synovial fluid concentrations of these metabolites between cryoablated and control hips. In contrast, alendronate did not normalize the concentration of these synovial fluid metabolites in the cryoablated hips.
  
  
  CONCLUSIONS
  Osteonecrosis of the femoral head is associated with alterations in synovial fluid glucose and lactate, reflecting anaerobic metabolism. These metabolites may serve as useful tools for monitoring response to revascularization therapies.
authors.affiliation: Physical Medicine and Rehabilitation Service, Durham Veterans Affairs Medical Center, Durham, NC, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Huffman
authors.forename: J R
authors.initials: JR
authors.lastname: Bowers
authors.forename: Z
authors.initials: Z
authors.lastname: Dailiana
authors.forename: J L
authors.initials: JL
authors.lastname: Huebner
authors.forename: J R
authors.initials: JR
authors.lastname: Urbaniak
authors.forename: V B
authors.initials: VB
authors.lastname: Kraus
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D016025:Bone Transplantation; D003131:Combined Modality Therapy; D004195:Disease Models, Animal; D004285:Dogs; D005271:Femur Head Necrosis / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D005947:Glucose / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D013582:Synovial Fluid / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000627:therapeutic use
chemical_list: D015415:Biomarkers; D042461:Vascular Endothelial Growth Factor A; D019344:Lactic Acid; D005947:Glucose