Anatomy Lab: Hindlimb and Its Joints

Pelvic Limb (Hindlimb) Regions

• The pelvic limb (hindlimb) consists of four regions: Pelvic Girdle, Thigh, Leg/Crus, and Hindpaw/Pes
• Pelvic Girdle: Ilium, Ischium, and Pubis
• Thigh: Femur (1) and Patella (1)
• Leg/Crus: Tibia (2) and Fibula (2)
• Hindpaw/Pes: Tarsal bones (7), Metatarsal bones (5), and Phalanges (12)

Pelvic Girdle/Pelvis/Hip

• The pelvic girdle consists of two similar bones: the os-coxae of both sides and the sacrum
• Os-coxae bones: Ilium, Ischium, and Pubis
• Fused ventrally by the symphysis pelvis/pelvic symphysis
• The symphysis pelvis consists of the ischial tuberosity posteriorly and the pubic symphysis anteriorly
• The pelvic cavity is a simple ovoid space enclosed by the pelvic bones
• The floor or ventral wall is formed by the pubis and ischium bones
• The roof or dorsal wall is formed by the sacrum and the first few caudal vertebrae
• The lateral walls are formed by the parts of the ilium, sacro-sciatic ligament, and the acetabular part of the ischia

Ischium

• Forms the caudal part of the os-coxae and enters into the formation of the acetabulum, obturator foramen, and ischiatic tuberosity
• Consists of tuberosity, body, table, and ramus
• The ischiatic tuberosity is the thick caudolateral margin of the bone
• The lateral angle of the tuber is enlarged and hooked, furnishing attachment for the sacrotuberous ligament
• The medial angle is rounded
• The ventral surface is the place of origin for the biceps femoris, semitendinosus, and semimembranosus

Pubis

• Extends from the ilium and ischium laterally to the symphysis medially
• The body of the pubis is the part lateral to the obturator foramen

Femur

• The largest bone in the body
• A typical long bone with a cylindrical body and two expanded extremities
• The flexor angle of the hip is about 110 degrees
• The third and lesser trochanters are located in about the same transverse plane
• The vastus parts of the quadriceps femoris attach to the smooth proximal cranial part of the femur
• The body of the femur is slightly convex cranially
• Viewed cranially, the body presents a smooth, rounded surface

Stifle (Knee) Joint

• A hinge joint with two cartilages/menisci
• Type: Hinge joint with two cartilages/menisci
• Femur and tibia - femorotibial (condylar)
• Femur and patella – femoropatellar (gliding joint)
• ROM: Flexion and extension; At the end of flexion, there is internal rotation; At the end of extension, there is external rotation

Hip Joint (Coxo-femoral joint)

• Type: Ball and socket; Femoral head and acetabulum of the ilium, ischium, and pubis
• A band of fibrocartilage on the rim of the acetabulum deepens the acetabulum
• ROM: Flexion and extension; Minimal adduction and abduction
• Supporting structures: Acetabular lip (fibrocartilage) continues as transverse ligament; Ligament of the femoral head; Synovial structures and tendon sheaths

Tarsal (Hock) Joint

• Supporting structures of canine hock: medial and lateral collateral ligaments
• Luxating Patella: Dislocation of kneecap