Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) shows no change in cartilage structural composition after viscosupplementation in patients with early-stage knee osteoarthritis.
BACKGROUND
Viscosupplementation with hyaluronic acid (HA) of osteoarthritic (OA) knee joints has a well-established positive effect on clinical symptoms. This effect, however, is only temporary and the working mechanism of HA injections is not clear. It was suggested that HA might have disease modifying properties because of its beneficial effect on cartilage sulphated glycosaminoglycan (sGAG) content. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) is a highly reproducible, non-invasive surrogate measure for sGAG content and hence composition of cartilage. The aim of this study was to assess whether improvement in cartilage structural composition is detected using dGEMRIC 14 weeks after 3 weekly injections with HA in patients with early-stage knee OA.


METHODS
In 20 early-stage knee OA patients (KLG I-II), 3D dGEMRIC at 3T was acquired before and 14 weeks after 3 weekly injections with HA. To evaluate patient symptoms, the knee injury and osteoarthritis outcome score (KOOS) and a numeric rating scale (NRS) for pain were recorded. To evaluate cartilage composition, six cartilage regions in the knee were analyzed on dGEMRIC. Outcomes of dGEMRIC, KOOS and NRS before and after HA were compared using paired t-testing. Since we performed multiple t-tests, we applied a Bonferroni-Holm correction to determine statistical significance for these analyses.


RESULTS
All KOOS subscales ('pain', 'symptoms', 'daily activities', 'sports' and 'quality of life') and the NRS pain improved significantly 14 weeks after Viscosupplementation with HA. Outcomes of dGEMRIC did not change significantly after HA compared to baseline in any of the cartilage regions analyzed in the knee.


CONCLUSIONS
Our results confirm previous findings reported in the literature, showing persisting improvement in symptomatic outcome measures in early-stage knee OA patients 14 weeks after Viscosupplementation. Outcomes of dGEMRIC, however, did not change after Viscosupplementation, indicating no change in cartilage structural composition as an explanation for the improvement of clinical symptoms.
Department of Orthopedic Surgery, Erasmus MC, University Medical Center, Rotterdam, The Netherlands ; Department of Radiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
Jasper
J
van Tiel
Max
M
Reijman
Pieter K
PK
Bos
Job
J
Hermans
Gerben M
GM
van Buul
Esther E
EE
Bron
Stefan
S
Klein
Jan A N
JA
Verhaar
Gabriel P
GP
Krestin
Sita M A
SM
Bierma-Zeinstra
Harrie
H
Weinans
Gyula
G
Kotek
Edwin H G
EH
Oei
D002358:Cartilage, Articular / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005682:Gadolinium; D006025:Glycosaminoglycans / Q000378:metabolism; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000378:metabolism / Q000473:pathology* / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome; D055676:Viscosupplementation
D006025:Glycosaminoglycans; D006820:Hyaluronic Acid; D005682:Gadolinium