Total Hip Replacement

Anatomy

The hip is one of the body’s largest joints. It is a ball-and-socket joint. The socket is formed by the acetabulum, which is part of the large pelvis bone. The ball is the femoral head, which is the upper end of the femur.

The bone surfaces of the ball and socket are covered with articular cartilage, a smooth tissue that cushions the ends of the bones and enables them to move easily. [1]

A thin tissue called synovial membrane surrounds the hip joint. In a healthy hip, this membrane makes a small amount of fluid that lubricates the cartilage and eliminates almost all friction during hip movement. [1]

Bands of tissue called ligaments (the hip capsule) connect the ball to the socket and provide stability to the joint. [1]

Description

“Total” means that the prosthesis concerns the two parts of the hip joint: the part of the pelvis (the acetabulum) and the part of the femur (the head of the femur). [2]

In a total hip replacement, also called hip arthroplasty, the damaged bone and cartilage are removed and replaced with prosthetic components. [1]
The damaged femoral head is removed and replaced with a metal stem that is placed into the hollow center of the femur. The femoral stem may be either cemented or “press fit” into the bone. [1]
A metal or ceramic ball is placed in the upper part of the stem, replacing the removed damaged femoral head. [1]
The damaged cartilage surface of the socket (acetabulum) is removed and replaced with a metal socket. Screws or cement are sometimes used to hold the socket in place. [1]
A plastic, ceramic or metal spacer is inserted between the new ball and the socket to allow a smooth gliding surface. [1]

When it is proposed?

A total hip prosthesis is normally suggested when the disability has become severe. Hip pain that limits your everyday activities, such as walking, bending or getting in and out of a chair, that continues while resting, either day or night, and stiffness that limits the ability to move, lift the leg or put on your shoes and socks, that aren’t relieved by anti-inflammatory drugs, physical therapy or walking supports, are good indicators to consider a total hip replacement surgery. [2]

Hip replacement surgery is a safe and effective procedure that can relieve your pain, increase motion, and help you get back to enjoying normal, everyday activities. [2]     

If, in addition, the osteoarthritis lesions are very advanced on the latest radiographs, this is another reason to consider it. [2]

Common causes of hip pain

The most common causes of chronic hip pain and disability is arthritis, being osteoarthritis, rheumatoid arthritis and traumatic arthritis the most common forms of this disease. [1]

• Osteoarthritis. This is an age-related “wear and tear” type of arthritis. It usually occurs in people 50 years of age and older and often in individuals with a family history of arthritis. The cartilage cushioning the bones of the hip wears away, causing the bones to rub against each other, causing hip pain and stiffness. Osteoarthritis may also be caused or accelerated by subtle irregularities in how the hip developed in childhood. [1]

• Rheumatoid arthritis. This is an autoimmune disease in which the synovial membrane becomes inflamed and thickened. This chronic inflammation can damage the cartilage, leading to pain and stiffness. Rheumatoid arthritis is the most common type of a group of disorders termed “inflammatory arthritis”. [1]

• Post-traumatic arthritis. This can follow a serious hip injury or fracture. The cartilage may become damaged and lead to hip pain and stiffness over time. [1]

•  Avascular necrosis. An injury to the hip, such as a dislocation or fracture, may limit the blood supply to the femoral head. This is called avascular necrosis. The lack of blood may cause the surface of the bone to collapse, and arthritis will result. Some diseases can also cause avascular necrosis. [1]

• Childhood hip disease. Some infants and children have hip problems. Even though the problems are successfully treated during childhood, they may still cause arthritis later on in life. This happens because the hip may not grow normally, and the joint surfaces are affected. [1]

Complications

The risk of venous thrombosis (blood clots) in the leg veins or pelvis is the most common complication of the hip replacement surgery. These clots can be life-threatening if they break free and travel to the lungs. This is easily surveilled and avoid through anticoagulant therapy (blood thinning medications), compression stockings, inflatable leg coverings, ankle pump exercises and early mobilization. [1]

Warning signs of a blood clot in your leg include [1]:

• Pain in your calf and leg that in unrelated to your incision;

• Tenderness or redness of your calf;

• Swelling of your thigh, calf, ankle or foot.

Warning signs or pulmonary embolism (blood clot that has traveled to your lung) include [1]:

• Sudden shortness of breath;

• Sudden onset of chest pain;

•  Localized chest pain with coughing.

Infection of the prosthesis is a less common complication that can also occur from a hip replacement surgery. This is prevented by measures taken before, during and after surgery. Pre-operatively, a “silent” infection (without symptoms), urinary or dental, should be sought. During the surgery, very rigorous aseptic standards must be observed. Lastly, after placing the prosthesis (and sometimes after several months or years), any distant infection of the prosthesis must be treated whether pulmonary, urinary or dental. An infection of the prosthesis requires prolonged hospitalization for an intravenous treatment or, possibly, replacement of the prosthesis. [2]

Physical Therapy

After a total hip replacement surgery, an early physical therapy is very important for you to return to your normal life, doing your normal activities.

The day after surgery, the physical therapist of the hospital where you are staying will come to your room and will gently mobilize your operated leg to soften your muscles and will demand you simple strengthening exercises. After this, he will ask you to seat at the edge of the bed and, if all goes well, he will ask you to stand up, with an aid of a walker, so you can lean on to it. After this, the physical therapist will lay you down on the bed again. This is very important because it permits you to have a vertical position.

The next days, the physical therapist, besides keeping mobilizing your hip and strengthening you hip muscles, will teach you how to start walking with the aid of walking supports. Initially you will start walking with a walker, then moving on to two elbow crutches, then one elbow crutch and, finally, with no aids at all or, if you feel safer, a cane. For a smooth walk with a walker you should advance your walker, then your operated leg and finally your “good” leg.

For the elbow crutches, first of all, you need to know how to adjust your crutches. The grip should be at the same height as your hips, and the semi-elliptical cuff should be at three to four fingers below your elbow. The rubber cap should have a great adherence to the floor to prevent you from slipping.

With two elbow crutches you should advance your two elbow crutches at the same level, then your operated leg, so that your foot will be between the elbow crutches, and then your “good” leg, a little bit forward then the foot of your operated leg. When you start to feel surer of yourself you can progress to an alternate walking, that is, you start by advancing the elbow crutch opposite to you operated hip and your operated hip, and then you advance the elbow crutch opposite to your “good leg” and your “good leg”.

After you have done enough strengthening and mobilization of your operated leg, and if you feel ready, ask your physical therapist, in the hospital or in a clinic, if you can now start to use only one crutch. To use only one elbow crutch, your physical therapist will tell you to keep using the crutch in the hand opposite to your affected hip. With one elbow crutch you advance your operated leg and your crutch at the same time. 

Be sure to tell your physical therapist if you have stairs at home, so he can teach how to climb and descend them.

To both climb and descend stairs, you should to do them step by step. To climb the stairs first you climb your elbow crutches, then your good leg and, finally, your operated leg. To descend the stairs you first descend your crutches, then your operated leg and, finally, your good leg.     

If you walk with only one elbow crutch and you have a stair rail, you can still descend and climb stairs with the crutch in the hand opposite to the hand rail.

When you get out of the hospital, you still need to find a physical therapist to continue the rehabilitation of your new hip.
Here is a video that shows you everything that I have just explained to you. I could only find videos with axillary crutches and not elbow crutches, but the principle is the same.

Here is another video that I have found interesting because it shows at the end of the video a way of mobility that you can use when you are going to bed or get out of the bed.

Strengthening exercises

For a good and normal walk, you need to strengthen all of the muscles that surround the operated hip, so the joint can be as stable as possible when you walk. The most important group of muscles are the quadriceps, the hamstrings and the gluteus medius. These muscle groups work together to support and stabilize the pelvic girdle. Without this support we would not be able to walk or move freely.

Below I will show you some videos of simple exercises that you can do at home.
Before doing any of these exercises at home, be sure to ask your physical therapist, for he is the only one that knows what your conditions are. He can also advice you of the weight-bearing you can or cannot do.

You can do 3 series of 10 repetitions, resting between series. Later, if the exercises become easy, you can add a charge on your ankle, beginning in 0.5 Kg to 2 Kg max, progressin little by little. Ask your physical therapist if and when you can add the charge.

Balance exercises

For even better total hip replacement rehabilitation, it is also very important to do some balance exercises. You can do simple balance exercises at your home. All you need is a chair. You can support yourself in the back of the chair while you lift you good leg up, nice and gently. With your leg up, you can slowly remove your hands from the back of the chair. Be aware of keeping your hands near the chair, in case you lose your balance. When you are stable doing this exercise, you can try to do it with your eyes closed, if you feel stable. If that causes you excessively pain, stop what you are doing and consult your physical therapist before continuing. If not, repeat this exercise 3 series of 10 repetitions, resting between series. 

Like the strengthening exercises, check your physical therapist before doing these exercises, for balance exercises can be more dangerous if they are not done correctly or at the right time. If you cannot put 100% charge on your operated leg, you cannot do this exercise.

Swelling

Swelling of the hip and leg after a hip replacement is normal. However, there are some things that you can do to minimize this problem. Ice the hip frequently, three times per day, 20 minutes each. Also ice after you have done your exercises.

If you have swelling of the entire leg is also normal. This will slowly improve, but there are various ways to help minimize the swelling:  

• Lie down and elevate the leg on several pillows. To effectively reduce swelling, your foot should be above your heart.  
• Use compression stockings. 
• Do your ankle pumps. This makes your muscles help remove some of the swelling. 
•  Avoid prolonged periods of sitting.

Dislocation

This occurs when the ball comes out of the socket. The risk for dislocating is greatest in the first few months after surgery while the tissues are healing. Dislocation is uncommon. If the ball does come out of the socket, a closed reduction usually can put it back into place without the need for more surgery. In situations in which the hip continues to dislocate, further surgery may be necessary.

This is prevented by strengthening the muscles around the prosthesis and avoiding “false moves” or certain actions in the months following the surgical procedure.

The movements that are to be avoided are:

    - Movements of internal rotation, like putting your shoes; movements of adduction of the hip, like when you are sleeping over the good side; or the two movements combined, like crossing of the legs when seated. To facilitate putting your shoes you can buy a shoe-horn. To prevent the adduction of the hip while sleeping, you can use a pillow between your knees.

    - Movements of flexion of the hip more than 90 degrees (lift your knee above your hip). That’s why you should never seat in a really low chair or crouch down to pick something of the floor. If you have to pick something of the floor, you move back your operated leg and you pick up the object in the floor, by bending the knee of the “good” leg, while you keep the operated leg extended.

In the image above it says 100 degrees, but I advise you 90 degrees (sorry, it was the best image I have found).

Driving an automobile

-        

     You are allowed to operate an automobile when you are comfortably walking with crutches and you have a good and comfort movement of the hip. But first, ask your physical therapist if you can start driving. To initiate driving, it is advised to practice in a place where there is no traffic, so you can move the foot of your affected hip between pedals at ease. To enter safely in the car, you should seat with the legs out of the car and pivot to the interior of the car.

Home planning

Several modifications can make your home easier to navigate during your recovery. The following items may help with daily activities: [1]

• Securely fastened safety bars or handrails in your shower or bath;

• Secure handrails along all stairways;

• A stable chair for your early recovery with a firm seat cushion (that allows your knees to remain lower than your hips), a firm back and two arms;

• A raised toilet seat;

• A stable shower bench or chair for bathing;

• A long- handled sponge and shower hose;

•  A dressing stick, a sock aid and a long-handled shoe horn for putting on and taking off your shoes and socks without excessively bending or  rotating your new hip;

• A reacher that will allow you to grab objects without excessively bending of you hip;

• Firm pillows for your chairs, sofas and car that enable you to sit with your knees lower than your hips;

• Removal of all loose carpets and electrical cords from the areas where you walk in your home.

  

Results

The list of complications should not make you forget that, in most cases, the patient’s life is transformed by the procedure. The absence of pain and recovery of a normal joint movement is accompanied by a return to usual activities (before the hip osteoarthritis) and a return to autonomy. [1]

Expectations

Total hip replacement is a great operation. It is highly predictable in terms of improvement in pain, function and quality of life. However, you must be patient to achieve many of these wonderful benefits of the surgery. The high quality pain relief that characterizes a good total hip replacement frequently takes, at least, 6 months. Patients predictably improve for up to a year after a hip replacement. [1]    

[1] American Academy of Orthopaedic Surgeons. Total Hip Replacement. OrthoInfo.org

[2] Expanscience laboratories. Total Hip Replacement: patient information sheet. Arthrolink.com