title: Mechanical chondroplasty: early metabolic consequences in vitro.
abstract: OBJECTIVE
  The purpose of this study was to determine the depth of penetration from mechanical chondroplasty and metabolic consequences of this procedure on the remaining articular cartilage.
  
  
  METHODS
  Mechanical chondroplasty was performed in vitro on a portion of fresh grade I or II articular cartilage from 8 human knee arthroplasty specimens. Treated and control (untreated) explants (approximately 30 mg) were cut from the cartilage. The explants were divided into 2 groups, day 1 and day 4, placed separately in a 48-well plate containing media, and incubated at 37 degrees C for 24 hours. After the 24-hour incubation, the explants were weighed on day 1 and day 4, and explant media were removed and tested for total proteoglycan synthesis and aggrecan synthesis. At time 0, 2 sets (2.6 mm each) of treated and control cartilage slices were cut with a precision saw. One set was stained for confocal laser microscopy via a cytotoxicity stain to determine cell viability. The second set was stained with H&E to determine depth of penetration.
  
  
  RESULTS
  The mean depth of penetration was 252.8 +/- 78 microm. There was no significant difference (P > .25) between total proteoglycan synthesis for control versus treatment groups on day 1 or 4. Aggrecan synthesis was significantly reduced on day 1 when normalized for tissue weight (P = .019) and double-stranded deoxyribonucleic acid (P = .004). On day 4, no significant difference was detected. Confocal laser microscopy did not show cell death below the zone of treatment.
  
  
  CONCLUSIONS
  There was no significant metabolic consequence caused by chondroplasty to the remaining articular cartilage, and the zone of injury was limited to the treatment area.
  
  
  CONCLUSIONS
  Mechanical chondroplasty causes no significant metabolic consequences to articular cartilage under these conditions.
authors.affiliation: Department of Orthopedics and Rehabilitation, University of Wisconsin Hospital and Clinic, Madison, Wisconsin, USA. Kaplan@orthorehab.wisc.edu
authors.forename: Lee D
authors.initials: LD
authors.lastname: Kaplan
authors.forename: Bryan
authors.initials: B
authors.lastname: Royce
authors.forename: Brian
authors.initials: B
authors.lastname: Meier
authors.forename: Justin M
authors.initials: JM
authors.lastname: Hoffmann
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Barlow
authors.forename: Yan
authors.initials: Y
authors.lastname: Lu
authors.forename: Herman F
authors.initials: HF
authors.lastname: Stampfli
mesh_terms: D053674:Aggrecans / Q000096:biosynthesis*; D001178:Arthroplasty; D001182:Arthroscopy; D002358:Cartilage, Articular / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery; D006801:Humans; D066298:In Vitro Techniques; D007719:Knee Joint / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery; D018613:Microscopy, Confocal; D011509:Proteoglycans / Q000096:biosynthesis*
chemical_list: D053674:Aggrecans; D011509:Proteoglycans