Fig 1.
a: Illustration of measurement of non-ossified region at tip of the keel (cartilage) (black bar). Visceral (dorsal) aspect of the keel bone plate and b: typical location of fractures and with substantial callus formation.
Table 1.
Overview of macroscopic fracture characteristics in birds selected for CT-scan and histomorphological fracture characterization.
Fig 2.
Lateral and dorsal (visceral) aspect of the keel bone of the adult chicken.
Sections of the keel bone 1) the caudal part (including the tip, processus xiphoideus); 2) the middle part; and 3) the cranial part (including carina sterni). Modified after [29].
Table 2.
Overview of keel length, ossification status and localization of fracture in 32 weeks old birdsa.
Fig 3.
3D model from CT scanning of keel bones: a,b, frontal and lateral view of the keel bone of a 32-week hen (barn floor) showing one fracture (arrow); c, d, frontal and lateral view the keel bone of a 85-week hen (cages) showing minimum three fracture (arrows).
Fig 4.
Distribution of the localization of fractures identified by CT scan in old (n = 38) and young birds (n = 10). Data is presented as percentage within age group.
Fig 5.
3D model (a) and CT image (b) of a 75+-week hen showing multiple fractures and the so-called pseudoarticulation (arrows).
Fig 6.
Age related distribution of remodeling status of the fracture lines identified by CT scan in old (n = 38) and young birds (n = 8).
Data is presented as percentage within age group.
Fig 7.
3D reconstruction (a,b,c,) and CT image (d) of a 75-week hen showing multiple fractures. Notice the radioopaque spots in the CT image.
Table 3.
Number of fractures observed in the caudal part of the keel bone by histological evaluation.
Fig 8.
Typical un-branched fracture line with minimal repair processes (HE stain).
Table 4.
Overview of inflammatory response and fracture repair in 38 birds with fracture lines in the caudal part of the keel bone observed by histological evaluation.
Table 5.
Overview of fracture repair in old birds from different housing types.