Craniolateral approach combined with a dorsal approach to the cat proximal femur
The craniolateral approach is commonly used to treat proximal femoral fractures. If more exposure is needed, it can be converted into a dorsal approach by performing an osteotomy of the greater trochanter.
In fractures affecting the subtrochanteric area the incision will be extended distally as needed.
For more information please see "Open approach to the femoral shaft".
In young growing animals with open growth plates, the vascular supply to the epiphysis is tenuous and every effort should be made to preserve it. In cats, less than 7 months of age, the vessel of the ligament of the head of the femur contributes to the epiphyseal blood supply.
(Pohlmeyer K. Arteries of the articulatio coxae and the proximal end of the femur in cats. Anat Histol Embryol. 1981;10:246– 256)
The angles of anteversion and the angle of inclination of the femoral neck must be preserved during reduction and stabilization of fractures of the proximal femur.
3. Skin incision
A skin incision is made starting at the midpoint between the greater trochanter and dorsal midline, and ending at the level of the proximal third of the femur. The subcutaneous fat and superficial fascia are incised directly under the skin incision.
The superficial fascia is retracted. The junction between the fascia lata and the biceps muscle is carefully identified by looking at the direction of the fibers.
The deep leaf of the fascia lata is incised proximally between the superficial gluteal and tensor fascia lata, and distally along the cranial border of the biceps femoris. The septum between the superficial gluteal muscle and the deep leaf of the fascia lata is not always easily identifiable in cats.
If muscle fibers are encountered, the incision should be directed more cranially.
The superficial and middle gluteal muscles are dorsally retracted. The superficial gluteal muscle can be transected at its attachment to the 3rd trochanter if necessary. The tendon of the deep gluteal muscle is identified, elevated from the joint capsule, and a partial tenotomy is performed close to its attachment to the greater trochanter if necessary.
The joint capsule, if not lacerated, is opened along the long axis of the femoral neck.
If more exposure is needed, a dorsal approach can be performed: the superficial gluteal muscle is transected near its insertion on the third trochanter, and a trochanteric osteotomy is performed with an oscillating saw, a Gigli wire or an osteotome.
Note: Care is taken with the trochanteric osteotomy to ensure that the deep and medial gluteal muscles are fully removed with the bone and the bone is adequate size to reattach.
Note: Care is taken to avoid damaging the sciatic nerve. If this approach is used, the partial tenotomy of the deep gluteal is not done because it is being removed with the greater trochanter.
The joint capsule is closed with absorbable suture material.
A tension relieving pattern is used to reattach the tendon of the deep gluteal muscle (if it was transected); the fascia is sutured using an absorbable suture. Both fascial layers can be sutured at once. Subcutaneous tissue and skin are routinely closed.
If a dorsal approach via a trochanteric osteotomy was performed, the greater trochanter is reattached using a tension band technique. The superficial; gluteal muscle is reattached to the lesser trochanter with sutures.