Ten coxofemoral joints from 5 dog cadavers were used to study the effect of coxofemoral positioning on passive hip laxity. A material test system was used to measure lateral translation when force was between 20 N of compression and 40 N of distraction. Using the orthogonal coordinate system imposed in this study, neutral position was empirically defined at 15 degrees of extension and 10 degrees of abduction, relative to the plane of the pelvis, and no internal or external rotation of the femur. The hips were mounted in a custom-designed jig that allowed 1 rotational degree of freedom (ie, either flexion/extension, adduction/abduction, or internal/external rotation), while holding the other 2 constant. Lateral translation of the hips was tested at 10 degrees intervals from 30 degrees of flexion to 70 degrees extension, 40 degrees of adduction to 60 degrees of abduction, and 30 degrees of internal rotation to 40 degrees of external rotation. Lateral displacement was maximal at 10 degrees of extension, 20 degrees of abduction, and 10 degrees of external rotation, approximating the neutral coxofemoral position during stance. As the hips were rotated into extreme positions, the amount of lateral displacement occurring with the same applied load decreased significantly to 32.0 to 65.3% of the maximal displacement. Determining the position of the hip associated with maximal passive laxity in vitro is essential to the design of a precise and accurate clinical stress-radiographic method to quantitate joint laxity in dogs. Our results confirm earlier work that passive hip joint laxity is at a maximum with the hip approximately in a neutral weight-bearing position.

The area of skin supplied by the afferent fibers in one cutaneous nerve is called the cutaneous area (CA) for that nerve. The CA of peripheral branches of lumbar and sacral spinal nerves responsive to the stimulation of hair follicle mechanoreceptors were mapped in 27 dogs. The amount of overlap among the CA was similar to that found for other CA of the body. The CA of peripheral branches of the sciatic nerve were restricted to the lateral, cranial, and caudal aspects of the pelvic limb distal to the stifle. The CA of the saphenous nerve was located on the medial side of the limb, except for a small area located on the lateral side of the crus. The distal part of the CA of the saphenous nerve was completely overlapped in the hind paw by branches of the superficial peroneal nerve laterally and the medial plantar branch of the tibial nerve medially. The CA for the deep peroneal nerve was located on the dorsal surface of the webbing between digits 2 and 3 and the adjacent skin of these digits. The CA of the plantar branches of the tibial nerve were small in comparison with the diameter of the nerve, suggesting that these branches contained nerve fibers supplying other, deeper structures in the hindpaw and that damage to these nerves would interfere with cutaneous sensation in only a small region on the plantar surface of the hindpaw. Knowledge of the CA of the various branches of the sciatic nerve allows more accurate localization of injury to the sciatic nerve or its branches by using areas of anesthesia.

Supernumerary ectopic limb(s) (SEL) is a congenital anomaly defined as the presence of accessory limb(s) attached to various body regions. This paper describes a case of SEL with ectopic lung and ectopia cordis in a newborn calf, based on macroscopic, microscopic and radiographic findings. External features of multiple congenital anomalies included an ectopic lung growing over the middle of the backbone and covered with normal haired skin. Ectopia cordis was found in the abdominal cavity and attached to the liver. Two extra abnormal limbs originated separately from within the ectopic lung. Most of the abdominal organs were exposed to the outside through the opened abdominal cavity. Microscopically the ectopic lung tissue had edema in the connective tissue around the bronchus and artery. Changes in other organs included congestion of the renal medulla, infiltration of inflammatory cells (lymphocytes and eosinophils) around the hepatic portal tract, and edema surrounding blood vessels and neurons in the brain. The rudimentary humerus of the forelimb was attached to the thoracic spine, as viewed radiographically. The hindlimb was consisted of an irregularly shaped femur, short tibia and fibula, two tarsal bones, one metatarsal bone, and three phalanges. This is the first description of congenital anomalies involving the SEL, ectopic lung and ectopia cordis in a calf.