Fibronectin-aggrecan complex as a marker for cartilage degradation in non-arthritic hips.
OBJECTIVE
To report hip synovial fluid cytokine concentrations in hips with and without radiographic arthritis.


METHODS
Patients with no arthritis (Tonnis grade 0) and patients with Tonnis grade 2 or greater hip osteoarthritis (OA) were identified from patients undergoing either hip arthroscopy or arthroplasty. Synovial fluid was collected at the time of portal establishment for those undergoing hip arthroscopy and prior to arthrotomy for the arthroplasty group. Analytes included fibronectin-aggrecan complex (FAC) as well as a standard 12 cytokine array. Variables recorded were Tonnis grade, centre-edge angle of Wiberg, as well as labrum and cartilage pathology for the hip arthroscopy cohort. A priori power analysis was conducted, and a Mann-Whitney U test and regression analyses were used with an alpha value of 0.05 set as significant.


RESULTS
Thirty-four patients were included (17 arthroplasty, 17 arthroscopy). FAC was the only analyte to show a significant difference between those with and without OA (p < 0.001). FAC had significantly higher concentration in those without radiographic evidence of OA undergoing microfracture versus those not receiving microfracture (p < 0.05).


CONCLUSIONS
There was a significantly higher FAC concentration in patients without radiographic OA. Additionally, those undergoing microfracture had increased levels of FAC. As FAC is a cartilage breakdown product, no significant amounts may be present in those with OA. In contrast, those undergoing microfracture have focal area(s) of cartilage breakdown. These data suggest that FAC may be useful in predicting cartilage pathology in those patients with hip pain but without radiographic evidence of arthritis.
Department of Orthopaedic Surgery, Stanford University, 450 Broadway St., Mail Code 6342, Redwood City, CA, 94063, USA, geoffa@stanford.edu.
Geoffrey D
GD
Abrams
Marc R
MR
Safran
Lauren M
LM
Shapiro
William J
WJ
Maloney
Stuart B
SB
Goodman
James I
JI
Huddleston
Michael J
MJ
Bellino
Gaetano J
GJ
Scuderi
D000328:Adult; D000368:Aged; D053674:Aggrecans / Q000032:analysis*; D001182:Arthroscopy; D015415:Biomarkers / Q000032:analysis; D002357:Cartilage Diseases / Q000473:pathology*; D016207:Cytokines / Q000032:analysis; D005260:Female; D005353:Fibronectins / Q000032:analysis*; D006621:Hip Joint / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000473:pathology / Q000601:surgery; D013582:Synovial Fluid / Q000737:chemistry*
D053674:Aggrecans; D015415:Biomarkers; D016207:Cytokines; D005353:Fibronectins