#Gluteal Aneurysm.#—­An aneurysm in the buttock may arise from the superior or from the inferior gluteal artery, but by the time it forms a salient swelling it is seldom possible to recognise by external examination in which vessel it takes origin.  The special symptoms to which it gives rise are pain down the limb from pressure on the sciatic nerve, and interference with the movements at the hip.

Ligation of the hypogastric (internal iliac) by the trans-peritoneal route is the most satisfactory method of treatment.  Extirpation of the sac is difficult and dangerous, especially when the aneurysm has spread into the pelvis.

#Femoral Aneurysm.#—­Aneurysm of the femoral artery beyond the origin of the profunda branch is usually traumatic in origin, and is more common in Scarpa’s triangle than in Hunter’s canal.  Any of the methods already described is available for their treatment—­the choice lying between Matas’ operation and ligation of the external iliac.

Aneurysm of the profunda femoris is distinguished from that of the main trunk by the fact that the pulses beyond are, in the former, unaffected, and by the normal artery being felt pulsating over or alongside the sac.

In aneurysmal varix, a not infrequent result of a bullet wound or a stab, the communication with the vein may involve the main trunk of the femoral artery.  Should operative interference become necessary as a result of progressive increase in size of the tumour, or progressive distension of the veins of the limb, an attempt should be made to separate the vessels concerned and to close the opening in each by suture.  If this is impracticable, the artery is tied above and below the communication; gangrene of the limb may supervene, and we have observed a case in which the gangrene extended up to the junction of the middle and lower thirds of the thigh, and in which recovery followed upon amputation of the thigh.

#Popliteal Aneurysm.#—­This is the most common surgical aneurysm, and is not infrequently met with in both limbs.  It is generally due to disease of the artery, and repeated slight strains, which are so liable to occur at the knee, play an important part in its formation.  In former times it was common in post-boys, from the repeated flexion and extension of the knee in riding.

The aneurysm is usually of the sacculated variety, and may spring from the front or from the back of the vessel.  It may exert pressure on the bones and ligaments of the joint, and it has been known to rupture into the articulation.  The pain, stiffness, and effusion into the joint which accompany these changes often lead to an erroneous diagnosis of joint disease.  The sac may press upon the popliteal artery or vein and their branches, causing congestion and oedema of the leg, and lead to gangrene.  Pressure on the tibial and common peroneal nerves gives rise to severe pain, muscular cramp, and weakness of the leg.