Table 1.

Synovial fluid biomarker concentrations assessed within 8 days of ACL injury^{15, 16}

Biomarker*	Abbreviation	Volume (Dilution)	CV†	LLOD‡	Number (%) below LLOD
Pro-inflammatory
Interleukin-1α (pg/mL)  Catalog # K151RBD, Meso Scale Discovery, Rockville, MD	IL-1α	25 μl (1:2)	9.9%	0.238 pg/ml	24 (69%)
Interleukin-1β (pg/mL)  Catalog #K151QPD, Meso Scale Discovery, Rockville, MD	IL-1β	25 μl (1:2)	5.7%	0.033 pg/ml	16 (46%)
Anti-inflammatory
Interleukin-1 receptor antagonist (pg/mL)  Catalog # DRA00B, R&D Systems, Minneapolis, MN	IL-1RA	100 μl (None)	4.4%	6.3 pg/ml	0 (0%)
Cartilage degradation
Sulfated glycosaminoglycan (μg/mL)  Catalog # BP-004, Kamiya Biomedical Company, Seattle, WA	sGAG	25 μl (None)	1.8%	N/A	0 (0%)
C-terminal crosslinked telopeptide of type II collagen (ng/mL)  Cartilaps®, Catalog # AC-10F1, Immunodiagnostic Systems, Inc, Fountain Hills, AZ	CTX-II	40 μl (None)	4.3%	0.20 μg/L	0 (0%)
Cartilage oligomeric matrix protein (μg/mL)  Catalog #RD194080200, BioVendor, Asheville, NC	COMP	5 μl (1:2500)	1.9%	0.4 ng/ml	0 (0%)
Matrix metalloproteinase 3 plex (MMP-1, MMP-3, MMP-9) (pg/mL)  Catalog # K15043C, Meso Scale Discovery, Rockville, MD	MMP-1	5 μl (1:20)	3.5%	1.74 pg/ml	0 (0%)
	MMP-3		4.5%	4.34 pg/ml	0 (0%)
	MMP-9		3.5%	14.3 pg/ml	0 (0%)
Bone Turnover
N-terminal crosslinked telopeptide of type I collagen (nM BCE)  Catalog # 9021, Osteomark ® NTx; Alere, Scarborough, ME	NTX-I	25 μl (1:5)	2.3%	N/A	0 (0%)
Hemarthrosis
Bilirubin + biliverdin (μmol/L)  In-house ELISA assay developed by Kraus Laboratory	B+B	30 μl (None)	1.3%	1.0 μmol/L	0 (0%)

^†CV = Mean inter-assay coefficient of variation

^‡LLOD = Lower limits of detection