What is Fibular Head Transposition?
Fibular head transposition is a surgical technique used to stabilize a stifle joint as a result of cranial cruciate ligament rupture.
The technique was first investigated in the 1980s as an alternative to other methods of cruciate ligament repair. It involves changing the location of the fibular head from a caudal to a cranial position. The lateral collateral ligament attaches to the fibular head, and in its new position, this collateral ligament mimics the stabilizing mechanics of the cranial cruciate ligament.
The main advantages of fibular head transposition is that the surgery does not involve entry into the joint itself, which means a shorter recovery period. In addition, the technique yields good results in arthritic stifles where other options for repair may give disappointing results.
However, in practice, fibular head transposition has not become a default procedure and is rarely performed. The technique itself requires moderate surgical skill and some basic orthopedic equipment and can be performed by a competent general surgeon in first opinion practice or by a specialist veterinary orthopedic surgeon.
Fibular Head Transposition Procedure in Cats
The reason for the cat's hind limb lameness must first be diagnosed as a CCL rupture. This is done through a combination of radiography and palpation of the joint under sedation.
Surgery involves a general anesthetic. The fur is clipped from the affected limb and the skin aseptically prepared. A longitudinal incision is made over the lateral aspect of the limb, centered on the stifle.
The ligaments attaching the head of the fibula to the tibia are transected to free it up. The fibular head is then manipulated cranially until the abnormal cranial draw in the knee is eliminated. The fibula is then held in its new position using a pin and fine wires. The skin incision is sutured and the cat woken from the anesthetic.
Efficacy of Fibular Head Transposition in Cats
Fibular head transposition holds promise as a less invasive means of stabilizing stifles in small dogs and cats. However, the initial excitement over this technique failed to live up to expectation, with much debate over whether rest alone would produce similar results. With several other options for correction of CCL rupture available, this technique has largely fallen out of usage.
Fibular Head Transposition Recovery in Cats
The cat wears a support bandage on the affected limb for a day after surgery. The cat is kept in a restricted space for seven days, and then a gradual return to normal activity encouraged. This is in contrast to other more invasive techniques that have a recovery time of three to six months.
Cost of Fibular Head Transposition in Cats
Orthopedic surgery is costly and a conservative estimate for a cruciate repair using fibular head transposition would be $700 upwards in first opinion practice. This does not include the assessment and diagnostic radiographs which represent a further $200 to $300. Indeed, if the patient is referred to a specialist that consultation is around $200, with surgery from $1,200.
Cat Fibular Head Transposition Considerations
This technique is little used and indeed many other extracapsular (outside the joint) procedures have likewise fallen out of favour. This is something of a puzzle as there is surprisingly little data on the comparative benefits and drawbacks of the different techniques.
The most successful surgery is likely to be the technique that the individual surgeon is most familiar with. Therefore when a surgeon is fluent in fibular head transposition the outcome is likely to be successful.
Should this particular technique fail to stabilize the joint, the good news is that intracapsular (inside the capsule) and bone remodelling techniques are still an option.
Fibular Head Transposition Prevention in Cats
CCL rupture is usually the consequence of trauma. Discouraging a cat from roaming and the inevitable exposure to motor vehicles will go a long way to preventing injuries including CCL rupture.