Fig 1.
Intraoperative images showing: (A) the intact perichondrial vasculature (white arrows) of the lateral trochlear ridge; (B) complete devascularization of the lateral trochlear ridge (area marked with dashed line) after resection of perichondrium and the nutrient vessels contained within; and (C) partial devascularization of the lateral trochlear ridge (area marked by dashed line) and the intact proximal portion of the nutrient vessel (white arrow).
Table 1.
MRI scan parameters for one stifle.
Fig 2.
T2 cartilage maps (A-C), subtracted CE-MRI image (D), and 3D DESS images (E and F) obtained 2, 6, and 12 weeks after complete devascularization of the lateral trochlear ridge in piglet 2. Dotted line in the subtracted CE-MRI image (D) marks the extent of hypoperfusion. Arrowheads identify a large OC-latens (B and E) and a subsequent OC-manifesta (C and F) lesion. Photomicrograph shows the histologic appearance of the extensive OC-manifesta lesion (dashed line) at 12 weeks postoperatively.
Fig 3.
T2 cartilage maps (A-C), subtracted CE-MRI image (D), and 3D DESS images (E and F) obtained 2, 6, and 12 weeks after complete devascularization of the lateral trochlear ridge in piglet 4. Dotted line in the subtracted CE-MRI image (D) marks the extent of hypoperfusion. Arrowheads identify a large OC-latens (B and E) and a subsequent OC-manifesta (C and F) lesion. Photomicrograph shows the histologic appearance of a large OC-manifesta lesion (dashed line) at 12 weeks postoperatively.
Fig 4.
T2 cartilage maps (A-C), subtracted CE-MRI image (D), and 3D DESS images (E and F) obtained 2, 6, and 12 weeks after partial devascularization of the lateral trochlear ridge in piglet 5. Dotted line in the subtracted CE-MRI image (D) marks the extent of hypoperfusion. Arrowheads identify a small OC-latens (B) and a subsequent healing OC-manifesta (C and F) lesion. Photomicrograph shows the histologic appearance of the healing OC-manifesta lesion (dashed line) at 12 weeks postoperatively.
Fig 5.
T2 cartilage maps (A-C), subtracted CE-MRI image (D), and 3D DESS images (E and F) obtained 2, 6, and 12 weeks after partial devascularization of the lateral trochlear ridge in piglet 8. Dotted line in the subtracted CE-MRI image (D) marks the extent of hypoperfusion. Arrowheads identify a small OC-latens (B) and a subsequent healing OC-manifesta (C and F) lesion. Photomicrograph shows the histologic appearance of the healing OC-manifesta lesion (dashed line) at 12 weeks postoperatively. A small OC lesion involving the growth plate (dotted line) is also apparent on histology but not observed on MRI.
Table 2.
Osteochondrosis lesion sizes.
Fig 6.
Representative histological images of all 10 piglets obtained 12 weeks after they underwent complete or partial devascularization of the lateral trochlear ridge of the femur.
Complete devascularization in Piglets # 1, 2, 3 and 4 led to the formation of extensive OC-manifesta lesions involving most of the lateral trochlear ridge. After partial devascularization, Piglet # 6 developed a medium sized OC-manifesta lesion involving a substantial portion of the epiphyseal cartilage; Piglets # 5, 7, 8, and 9 had healing OC-manifesta lesions nearly completely surrounded by bone; and Piglet # 10 had no apparent lesion on histology. Lesions are marked with black arrows.