Arthroscopic estimation of the extent of chondropathy.
ABSTRACT Arthroscopy has been used to evaluate articular cartilage (AC) pathology in osteoarthritis (OA) for outcome measurement and validation of non-invasive imaging. However, many fundamental aspects of arthroscopic assessment remain un-validated.
This study evaluated arthroscopic estimates of extent of chondropathy.
Serial arthroscopic assessments were performed in a group of 15 sheep before and after bilateral stifle medial meniscectomy (MMx). Post-mortem assessments were performed in un-MMx sheep and 4 and 16 weeks post-MMx. Arthroscopic assessments of the extent of each grade of chondropathy were compared with a non-arthroscopic hybrid assessment that incorporated biomechanical, thickness and macroscopic assessments.
Arthroscopy evaluated only 36% of AC and missed significant pathological changes, softening and chondro-osteophyte, occurring in peripheral regions. The patterns of change in arthroscopic assessments were similar to those of the non-arthroscopic assessment but there was a very strong tendency to over-estimate the extent of softened AC after MMx. In spite of these limitations arthroscopic assessments were responsive to change. Estimates of the extent of normal and softened AC were most responsive to change over time followed by estimates of superficial and deep fibrillation. Arthroscopy was as an excellent discriminator between normal and OA. Assessments of chondro-osteophyte and exposed bone were not responsive to change.
Arthroscopic estimates of extent of chondropathy are prone to substantial error. While experience and training may reduce these errors other approaches may more effectively improve performance.
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ABSTRACT: To review the performance of arthroscopic assessment of articular cartilage damage in osteoarthritis. The literature was reviewed for publications containing data regarding validity and reliability of arthroscopic systems of cartilage evaluation in knee osteoarthritis. Fifty-two distinct measurement systems were identified in 60 publications. There were 30 simple severity-scoring systems, 3 global visual analogue scale systems, and 19 composite systems. No systems consisted solely of measurements of lesion size or site, although 13 systems used either or both of these for the calculation of composite scores. Only 6 publications (10%) undertook any reliability evaluation and these generally used inappropriate methods of statistical analysis. Thirty-five publications (58%) evaluated validity. Construct validity was tested using several constructs (clinical in 2, magnetic resonance imaging in 10, radiographs in 10, or other arthroscopic assessments in 5 publications). Criterion validity was ascertained by using several methods including cartilage histology, histochemistry, or biomechanics in 10 publications. Responsiveness was determined in 1 publication. Many publications evaluated composite systems but only a few evaluated fundamental aspects of arthroscopic measurement. Conceptually, composite scoring systems have the best validity; however, at present, there is only enough evidence to support the use of simple chondropathy severity scores and there are little data on the responsiveness of these methods. A proposed program for comprehensive evaluation and development of valid and responsive arthroscopic assessments of articular cartilage is outlined.Seminars in Arthritis and Rheumatism 11/2003; 33(2):83-105. · 3.81 Impact Factor
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ABSTRACT: Omeract IV started a discussion on the development of radiological response criteria in rheumatoid arthritis (RA). Such criteria depend on the definition of what constitutes the minimum clinically important progression of damage. Because such a definition is currently not available, as a first step we have used the concept of random measurement error to determine what is the smallest detectable difference (SDD) in radiological progression between 2 radiographs of a particular patient. Baseline and 12 month radiographs (hands, wrists, feet) of 52 patients representative of the spectrum of radiological progression were selected from a randomized controlled trial of early rheumatoid arthritis (COBRA study) and were read paired and chronologically by 2 observers using the van der Heijde modified Sharp method (0-448 scale) and another 2 observers using the Scott modified Larsen method (0-200). The measurement error of progression was determined using the metric 95% limits of agreement method of Bland and Altman. In the setting of early RA the SDD is 11 modified Sharp score units and 8 modified Larsen score units if there is an equal distribution of baseline damage and progression in the sample and the mean score of the same trained observers is always used. The SDD is 15.5 modified Sharp score units and 11 modified Larsen score units if there is an equal distribution of baseline damage and progression in the sample and the mean score of any 2 trained observers is used. Other SDD were determined depending on the context of measurement. Although this exercise needs repetition in other settings, the SDD is a useful starting point in the development of radiological response criteria.The Journal of Rheumatology 04/1999; 26(3):731-9. · 3.26 Impact Factor
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ABSTRACT: This study investigates the accuracy and reliability of a novel handheld indentation system designed to ascertain the dynamic biomechanical properties of articular cartilage. A series of standard elastomers were assessed with both the handheld indentation system and a bench-top dynamic indentation system to assess the accuracy of the instrument. Interoperator and intraoperator experiments were undertaken to investigate the reliability of the system when used by an individual operator and by five different operators. Intraclass coefficients (Rho) were derived using a random effects model. The system was then used to ascertain the topographical variation in the shear moduli and phase lag of articular cartilage across normal ovine tibial plateaux. The system was shown to be highly accurate (R2 = 0.97), and had excellent reliability when measuring the dynamic shear modulus of articular cartilage (interoperator Rho = 0.75, intraoperator Rho = 0.79). Measurement of static shear modulus was less reliable (interoperator Rho = 0.15, intraoperator Rho = 0.52), but may be improved by monitoring the load applied to the instrument by the operator. The instrument was used to differentiate between different regions of cartilage and generated a topographical map of an ovine tibial plateau. The cartilage located beneath the menisci was 200-500% stiffer than the cartilage that was not covered by the menisci, while the phase lag was almost constant (10+/-2 SD) over the entire tibial plateau. The system was shown to be an accurate and reliable tool for rapidly assessing the dynamic biomechanical properties of articular cartilage, while being small enough to be used arthroscopically.Physics in Medicine and Biology 03/2001; 46(2):541-50. · 2.70 Impact Factor