Femoral Head and Neck Osteotomy (FHNO)
What is a Femoral Head and Neck Osteotomy? (FHNO)
A femoral head and neck osteotomy, or FHNO, is the surgical removal of the head and neck of the femur. In simpler terms, it is the removal of the ball part of the ball-and-socket that makes up the hip joint. This way, the bones of the joint are no longer in contact, which alleviates the pain that is caused by the abnormal contact of the bones in pets.
Is my pet a candidate for FHNO?
This procedure is usually used as a last resort procedure in pets with femoral head and neck fractures, severe arthritis of the hip, Legg-Perthes disease (known as avascular necrosis of the femoral head). Once the femoral head and neck are removed, the surrounding muscles and developing scar tissue work to support the area, and act as a false joint. The ultimate is goal is to restore pain-free mobility. This means that now when the limb is moved, the forces are transferred to the pelvis rather than the leg itself. Most pets return to normal activity after surgery.
In many cases, the goal of the FHNO procedure is to relieve pain associated with hip dysplasia, rather than create a joint with completely normal function. Therefore, while there are no specific weight guidelines for the use of an FHNO, smaller pets typically have a better outcome since less stress and force is carried on the false joint than would be in a large pets.
This radiograph shows both femoral heads are out (luxated) and requires a FHNO.
This radiographs is a pelvic view after the procedure. Both femoral heads have been removed.
What is the recovery period like?
A FHNO typically requires 6-8 weeks of recovery. This means no running, jumping, going up or downstairs at all for the duration of the recovery time. Pet’s are typically lame at first but then gradually improve as they move further into their recovery period. Pain medication is usually given for the duration of the recovery period if necessary. There are no bandages or recheck radiographs required.