Approaches for minimally invasive osteosynthesis (MIO) to the cat femoral shaft
Surgical approaches to the distal and proximal ends of the femur are used for minimally invasive osteosynthesis. The following surgical approach has been described by Pozzi in VCOT 4/2009 316-320.
2. Proximal approach: Skin incision
A 3 to 5 cm long incision is made distal to the greater trochanter of the femur.
Following retraction of the skin and subcutaneous tissue, an incision is made through the superficial and deep leafs of the fascia lata along the cranial border of the biceps femoris muscle. Caudal retraction of the biceps femoris muscle exposes the origin of the vastus lateralis on the intertrochanteric crest. Partial elevation of the vastus muscle from the crest may be required to expose the proximal shaft of the femur.
3. Distal approach: Skin incision
After palpation of the patella and the lateral trochlear ridge, a 2 to 4 cm longitudinal skin incision is made, beginning at the level of the patella and extending proximally.
The fascia lata is incised along the cranial border of the biceps femoris muscle. The biceps femoris is retracted caudally. The intermuscular septum attached to the femur and located between the vastus lateralis muscle and the biceps femoris muscle is incised to allow adequate muscle retraction. A branch of the distal caudal femoral artery may have to be ligated or cauterized and transected as it enters the vastus lateralis muscle distally. Retraction of the vastus lateralis muscle cranially and the biceps femoris muscle caudally exposes the distal femoral metaphysis.
Creation of the epiperiosteal tunnel
An epiperiosteal tunnel is created from distal to proximal by carefully inserting long soft tissue elevator or long, straight Metzembaum scissors under the biceps femoris and vastus lateralis muscles, until the tip of the instrument is seen through the proximal incision.