Animal models of osteoarthritis: characterization of a model induced by Mono-Iodo-Acetate injected in rabbits

Figures & data

Figure 1. Induction of osteoarthritis by intra-articular injection of MIA

Table 1. Macroscopic score of degenerative lesions in cartilage as recommended by OARSI

1	Intact surface: surface normal in appearance and does not retain India ink
2	0 mm<Fissures < 4 mm
3	4 mm<Fissures < 8 mm
4	8 mm<Fissures
5	0 mm<Full depth erosion < 2 mm
6	2 mm< Full depth erosion < 5 mm
7	5 mm< Full depth erosion

Laverty et All [7]

Table 2. Summary of the means, variances and probabilities of the different groups for the macroscopic, radiological and microscopic parameters

	Groups	Number of samples	Total	mean	Variance	P value
Macroscopic Score	G 1	6	10. 4	1. 73	0. 122
	G 2	6	20. 7	3. 45	0. 215	< 0. 05
	G 3	6	32. 4	5. 4	0. 168
	G 4	6	39. 6	6. 6	0. 248
Radiological Score	G 1	6	3. 5	0. 583	0. 441
	G 2	6	18. 25	3. 041	0. 635	<0. 05
	G 3	6	37	6. 166	0. 591
	G 4	6	49. 75	8. 29	0. 235
icroscopic Score of cartilage	G 1	6	18	3	0. 5
	G2	6	46	7. 66	2. 16	< 0. 05
	G3	6	83	13. 83	1. 066
	G 4	6	121. 5	20. 25	1. 075

Figure 2. Osteoarthritis induced by MIA: macroscopic appearance of cartilage with (a) and without Indian ink (b)

Figure 3. Macroscopic and radiological appearance of osteophytes and degenerative alterations

Figure 4. Osteoarthritis induced by MIA: (a) cartilage (b) synovium (c) menisci: microscopic appearance of cartilage

Table

Parameter
Safranin O-fast green staining
0 = uniform staining throughout articular cartilage
1 = loss of staining in superficial zone of hyaline cartilage <50% of the length of the condyle or plateau
2 = loss of staining in superficial zone of hyaline cartilage >50% of the length of the condyle or plateau
3 = loss of staining in the upper 2/3’s of hyaline cartilage <50% of the length of the condyle or plateau
4 = loss of staining in the upper 2/3’s of hyaline cartilage >50% of the length of the condyle or plateau
5 = loss of staining in all of hyaline cartilage <50% of the length of the condyle or plateau
6 = loss of staining in all of hyaline cartilage >50% of the length of the condyle or plateau
Structure
0 = Normal
1 = Surface irregularities
2 = Fissures in <50% surface
3 = Fissures in >50% surface
4 = erosion 1/3 hyalin cartilage <50% surface
5 = erosion 1/3 hyalin cartilage >50% surface
6 = erosion 2/3 hyalin cartilage <50% surface
7 = erosion 2/3 hyalin cartilage >50% surface
8 = full depth erosion hyalin cartilage <50% surface
9 = full depth erosion hyalin cartilage >50% surface
10 = full depth erosion hyaline and calcified cartilage to the subchondral bone <50% surface
11 = full depth erosion hyaline and calcified cartilage to the subchondral bone >50% surface
Chondrocyte density
0 = No decrease in cells
1 = focal decrease in cells
2 = multifocal decrease in cells
3 = multifocal confluent decrease in cells
4 = diffuse decrease in cells
Cluster formation
0 = Normal
1 = <4 clusters
2 = >4 but <8 clusters
3 = >8 clusters

Table

Synoviocyteproliferation	0 normal 1 slight 2 moderate 3 severe	One layer Up to two cells deep Up to four cells deep Up to more than four cells deep
Hypertrophy	0 normal 1 slight 2 moderate 3 severe	Squamous Cuboidal Cylindrical Cylindrical withcytoplasmic protrusions
Inflammatory infiltrate	0 absent 1 slight 2 moderate 3 severe	Few cells Some foci of cells Diffuse infiltration
Fibrinous exudate	0 absent 1 slight 2 moderate 3 severe	Slight amount,focal Multifocal deposits of fibrin Diffuse deposits of fibrine
Lymphoplasmacytic infiltrate	0 absent 1 slight 2 moderate 3 severe	Single/few cells Some cells, mainly arrounvessels Many cells,diffuse infiltration
Lymphoplasmacytic aggregates	0 Absent 1 single 2 many	1 >1
Synovial stroma villous hyperplasia	0 absent 1 slight 2 moderate 3 severe	No villi/smooth waves Some small villi Multifocal villous hyperplasia Diffusevillous hyperplasia
Proliferation of fibroblasts/fibrocytes	0 absent 1 slight 2 moderate 3 severe	Normal cellularity density Mild proliferation Moderate proliferation Extensive proliferation
Proliferation of blood vessels	0 normal 1 slight 2 moderate 3 severe	Mild proliferation Moderate proliferation Extensive proliferation
Cartilage/bone_detritus	0 absent 1 few 2 many	1–3 >3
Hemosiderosis	0 absent 2 few cells 3 many cells	1–3 >3

Table

	Scoring category	Observations	Score
	Menisci calcification	None	0
		1	1
		2	2
Number of visible osteophytes	Medial tibial condyle	None	0
		Low- Moderate	1
		Moderate- Severe	2
	Medial femoral condyle	None	0
		Low- Moderate	1
		Moderate- Severe	2
	Medial fabella	Absence	0
		Presence	1
	Structural modifications of subchondral bone (sclerosis)	None	0
		Low- Moderate	1
		Moderate- High	2
	Width of the joint space	Normal	0
		Reduced	1
		Absent	2
	Calcification of tendons and ligaments	None	0
		1 site	1
		>1 site	2
		Total	13

Laverty S, Girard CA, Williams JM, et al. The OARSI histopathology initiative – recommendations for histological assessments of osteoarthritis in the rabbit. Osteoarthritis Cartilage. 2010 Oct;18:S5365.

 Google Scholar