UNILATERAL COXOFEMORAL EXCISION ARTHROPASTY
A coxofemoral excision arthroplasty involves the surgical removal of the femoral head and neck. It is a salvage procedure with the goal to eliminate bone to bone contact at the hip and results in the formation of a functional pseudarthrosis (a scar tissue joint).
It was first described as a treatment for dogs with hip dysplasia in 1961. This surgical option is indicated in cases of canine hip dysplasia, Legg-Calve-Perthés disease, non-reparable fractures of the acetabulum or femoral head, osteoarthritis, chronic recurrent hip luxations, osteomyelitisand septic arthritis, failed total hip replacement or villinodular synovitis of the hip joint.
IMPORTANCE OF POST SURGERY PHYSICAL THERAPY
Physical therapy should be started the day after surgery, and incorporate range of motion (ROM) into flexion, extension and abduction. Aggressive analgesic therapy may assist in early ambulation and rapid return to normal function. As well, use of therapeutic modalities can aid in pain relief and soft tissue healing and hence improved functioning.
However, cases that are not referred for physiotherapy immediately post‐op may exhibit severe loss of range of motion and muscle wastage depending on the length of delay before obtaining these services. The goals in treating these cases are to maximize weight bearing, gain ROM or muscle extensibility, strengthen the affected limb, stimulate soft tissue healing, provide pain relief following an aggressive physiotherapy stretching or exercise treatment session, and address proprioception deficits.
Facilitation of Weight bearing
It is imperative that the animal actually use the post‐operative limb, so any safe exercise that encourage limb use can be utilized. Various therapeutic exercise techniques have been described to stimulate weight bearing on any post‐operative limb.
Gain Range of Motion
Regaining hip extension is a one of the most important goals when rehabilitating this type patient. Passive range of motion (PROM) may help to regain extension, however an animal that has been avoiding this movement, the physiotherapist will need to be tricked into extending its hips.
Strengthening
Atrophy of the hind limb muscle mass should be addressed post‐operatively. Various treatment techniques can be used to strengthen the muscles of the hip and thigh. For dogs that are unable to walk, NMES and TENS are often applied.
Pain relief and soft tissue healing
The FHNE surgery may have resulted in adhesions to the distal muscle secondary to tracking of blood from the surgical site and soft tissue damage done at the same time. As well, the techniques listed above may result in mild soft tissue soreness. Therapies that may address this could include modalities and/or massage.
It is well known that healing of soft tissue structures can be accomplished with ultrasound, Low Level Light Therpy (LLLT or also commonly known as Cold Laser), or pulsed electromagnetic field therapy. The tissues surrounding the hip joint as well as the quadriceps and sartorius muscle may benefit from these treatments in regards to the surgically induced trauma. Non‐noxious sensory stimuli reduces blood pressure, changes secretion of corticotropin releasing hormone and increases pain thresholds in rats.
In humans, it produces pain relief and increase the plasma concentration of B‐endorphins. All of these effects could provide comfort to the animal, hence encouraging use and relieving post‐exercise discomfort.
Proprioceptive Retraining
As the limb begins to heal and the dog is utilizing it consistently in gait, the next goal should be to retrain proprioception of the affected leg. Proprioception is the minds awareness of the where the body is in space. Several exercises have been described to address co‐ordination and muscular control of a limb.
