Reliability and Validity of the Arthroscopic International Cartilage Repair Society Classification System: Correlation With Histological Assessment of Depth.
OBJECTIVE
To determine the interobserver reliability of the International Cartilage Repair Society (ICRS) grading system of chondral lesions in cadavers, to determine the intraobserver reliability of the ICRS grading system comparing arthroscopy and video assessment, and to compare the arthroscopic ICRS grading system with histological grading of lesion depth.


METHODS
Eighteen lesions in 5 cadaveric knee specimens were arthroscopically graded by 7 fellowship-trained arthroscopic surgeons using the ICRS classification system. The arthroscopic video of each lesion was sent to the surgeons 6 weeks later for repeat grading and determination of intraobserver reliability. Lesions were biopsied, and the depth of the cartilage lesion was assessed. Reliability was calculated using intraclass correlations.


RESULTS
The interobserver reliability was 0.67 (95% confidence interval, 0.5-0.89) for the arthroscopic grading, and the intraobserver reliability with the video grading was 0.8 (95% confidence interval, 0.67-0.9). A high correlation was seen between the arthroscopic grading of depth and the histological grading of depth (0.91); on average, surgeons graded lesions using arthroscopy a mean of 0.37 (range, 0-0.86) deeper than the histological grade.


CONCLUSIONS
The arthroscopic ICRS classification system has good interobserver and intraobserver reliability. A high correlation with histological assessment of depth provides evidence of validity for this classification system.


CONCLUSIONS
As cartilage lesions are treated on the basis of the arthroscopic ICRS classification, it is important to ascertain the reliability and validity of this method.
Department of Surgery, Division of Orthopedics, University of Toronto Orthopaedic Sports Medicine, Toronto, Ontario, Canada; Women's College Hospital, Toronto, Ontario, Canada; Mt Sinai Hospital, Toronto, Ontario, Canada. Electronic address: tim.dwyer@wchospital.ca.
Tim
T
Dwyer
Department of Surgery, Division of Orthopedics, University of Toronto Orthopaedic Sports Medicine, Toronto, Ontario, Canada.
C Ryan
CR
Martin
Mt Sinai Hospital, Toronto, Ontario, Canada.
Rita
R
Kendra
Mt Sinai Hospital, Toronto, Ontario, Canada.
Corey
C
Sermer
Department of Surgery, Division of Orthopedics, University of Toronto Orthopaedic Sports Medicine, Toronto, Ontario, Canada; Women's College Hospital, Toronto, Ontario, Canada.
Jaskarndip
J
Chahal
Department of Surgery, Division of Orthopedics, University of Toronto Orthopaedic Sports Medicine, Toronto, Ontario, Canada; Women's College Hospital, Toronto, Ontario, Canada.
Darrell
D
Ogilvie-Harris
Department of Surgery, Division of Orthopedics, University of Toronto Orthopaedic Sports Medicine, Toronto, Ontario, Canada; Women's College Hospital, Toronto, Ontario, Canada.
Daniel
D
Whelan
Department of Surgery, Division of Orthopedics, University of Toronto Orthopaedic Sports Medicine, Toronto, Ontario, Canada; Women's College Hospital, Toronto, Ontario, Canada.
Lucas
L
Murnaghan
Department of Surgery, Division of Orthopedics, University of Toronto Orthopaedic Sports Medicine, Toronto, Ontario, Canada.
Aaron
A
Nauth
Department of Surgery, Division of Orthopedics, University of Toronto Orthopaedic Sports Medicine, Toronto, Ontario, Canada; Women's College Hospital, Toronto, Ontario, Canada; Mt Sinai Hospital, Toronto, Ontario, Canada.
John
J
Theodoropoulos
D001182:Arthroscopy / Q000379:methods / Q000592:standards*; D001706:Biopsy; D002102:Cadaver; D002358:Cartilage, Articular / Q000473:pathology*; D006801:Humans; D015601:Injury Severity Score; D007592:Joint Diseases / Q000473:pathology*; D007719:Knee Joint / Q000473:pathology* / Q000601:surgery; D015203:Reproducibility of Results