Page 83 - Adams and Stashak's Lameness in Horses, 7th Edition

Functional Anatomy of the Equine Musculoskeletal System 49

Biceps femoris m. (cut and reflected)
VetBooks.ir

Lateral femoropatellar
ligament

Lateral femorotibial
ligament
Tendon of popliteus m.

Lateral head of
gastrocnemius m.

Common peroneal n.
Long digital extensor m.

Lateral digital extensor m.
Deep peroneal n.
Superficial peroneal n.

Figure 1.44. Deep dissection of lateral aspect of left stifle with femoral and tibial condylar surfaces indicated by dashed lines. Please note
that the term “fibularis” has superseded “peroneus” (fibular rather than peroneal), although both are widely used.

Caudal Aspect vessels. The larger cranial artery, the main blood supply
The caudal femoral nerve supplies the skin of the cau­ to the pes, deviates laterad into the interosseous space
dal aspect of the stifle. The caudal part of the biceps between the tibia and fibula; the smaller caudal tibial
femoris muscle covers the lateral head of the gastrocne­ artery continues distad between the tibia and the popli­
teus muscle. Satellite veins of the same name accompany
mius; a division of the biceps femoris inserts on the cra­
nial border of the tibia, while another continues distad these vessels.
The triangular popliteus muscle extends mediodistad
to attach to crural fascia and the calcaneal tuber. The
semitendinosus muscle sweeps to its insertion on the cra­ from its origin on the lateral epicondyle of the femur
(Figure 1.44). The tendon of origin passes deep to the
nial border of the tibia and distad toward its tarsal inser­
tion, covering the medial head of the gastrocnemius. The lateral collateral ligament of the stifle joint, partly envel­
oped in its course by an extension of the femorotibial
tendons of the two heads of the gastrocnemius combine,
and in the proximal part of the crus, the tendon is super­ joint capsule. The popliteus broadens and inserts on the
medial part of the caudal tibia, lying alongside the
ficial to the tendon of the superficial digital flexor mus­
cle. Separation of the two heads of the gastrocnemius medial head of the deep digital flexor (Figure 1.45).
muscle reveals the tendinous superficial digital flexor
muscle that arises in the supracondylar fossa of the Medial Aspect
femur between the two heads, its initial part embedded
in the lateral head (Figure 1.45). Skin and fascia on the medial aspect of the stifle are
After giving rise to the caudal cutaneous sural nerve, supplied by the saphenous and lateral cutaneous femo­
the tibial nerve descends between the two heads of the ral nerves. The region is traversed by the medial saphen­
gastrocnemius along the medial side of the superficial ous vein and the saphenous artery and nerve. Cranially,
digital flexor. The tibial nerve supplies the gastrocne­ the vastus medialis of the quadriceps femoris muscle
mius, soleus, superficial digital flexor, deep digital flexor, attaches to the parapatellar fibrocartilage, medial bor­
and popliteus muscles. The femoral artery gives off the der of the patella, and medial patellar ligament. The
distal caudal femoral vessels and continues as the pop­ strap‐like sartorius muscle attaches to the medial patel­
liteal artery, descending between the two heads of the lar ligament and the tibial tuberosity. Caudal to the sar­
gastrocnemius (Figure 1.46). Distal to the stifle joint, the torius, the gracilis muscle also attaches to the medial
popliteal vessels divide into cranial and caudal tibial patellar ligament and to the medial collateral ligament