Hips can be tricky. For pet parents, dealing with diseases of the hip can be even trickier (and without pet insurance – costly!).
The hip joint is a “ball and socket” type joint. The ball is the rounded head of the leg bone (or femur), and the socket is located in the pelvis and cups around the ball. The round ligament of the femoral head holds the ball in the socket, and the surrounding hip muscles help support the joint.
Though nearly perfect in design, the hip joint is not without its weaknesses – especially in dogs who are predisposed to hip dysplasia and have shallow sockets. With enough force, even the strongest ligaments and muscles can’t keep the hip joint in place, and the hip can become dislocated.
A dislocated (or luxated) hip occurs when the ball part of the joint separates from the socket. Blunt trauma – like being hit by a car – can cause this type of injury. Affected dogs and cats will not be able to bear weight on their back leg, and the affected leg may appear shorter than the other three. Hip luxations are extremely painful.
If your pet suffers trauma or begins limping, and you suspect he or she may have dislocated a hip, your veterinarian will want to take an X-ray to check the positioning of the hip. Most often, the leg bone slides up and forward, but in some cases the opposite can happen. Knowing where the ball of the joint is located will help your veterinarian correct the problem. Radiographs will reveal if there are fractures in the pelvis or leg which may interfere with correction.
There are two approaches to trying to correct a dislocated hip. The first is through a closed reduction, where the veterinarian tries to manually re-place the hip in its proper location without surgery. Since this procedure is painful, and the vet needs the leg muscles relaxed, your pet will first be anesthetized. Once the joint is back in place, your vet will place the leg in a sling to prevent weight bearing and to encourage the joint to stay in place. Unfortunately, closed reduction can fail as often as it resolves the problem; there’s generally a 50% recurrence of dislocation (although that also means 50% of them stay put!).
If closed reduction fails, open (or surgical) reduction should be considered. There are several options for open reduction, including suturing of the joint capsule and the use of small pins to hold the joint in place.
Smaller dogs and cats may also choose a procedure called a femoral head ostectomy (FHO), in which the ball part of the joint is simply cut off of the femur and removed. Over time, the muscles around the area will create a false joint. This procedure is not used for dogs over fifty pounds.
Whatever the case, if your dog or cat experiences a hip luxation, he or she will be more likely to experience arthritis is that hip with age. Do your pet a favor and ensure that they stay at a proper weight, as any extra pounds will exacerbate the problem. Consider starting supplements, like glucosamine and fatty acids, for joint support.
A pet that is non-weight bearing should always be seen by a veterinarian as quickly as possible. Whether a dislocated hip, fractured limb or ligament injury is to blame, pet health insurance will help take the worry out of the repair bill!
Has your pet ever experienced a dislocated hip? Tell us about the experience in the comments below!