Normal hip Joint

             The hip joint is located where the thigh bone (femur) meets the pelvic bone. It is a “ball and socket” joint. The upper end of the femur is formed into a round ball (the “head” of the femur). A cavity in the pelvic bone forms the socket (acetabulum). The ball is normally held in the socket by very powerful ligaments that form a complete sleeve around the joint (the joint capsule). The capsule has a delicate lining (the synovium). The head of the femur is covered with a layer of smooth cartilage which is a fairly soft, white substance about 1/8 inch thick. The socket is also lined with cartilage (also about 1/8 inch thick). The cartilage cushions the joint, and allows the bones to move on each other with very little friction. An x-ray of the hip joint usually shows a “space” between the ball and the socket because the cartilage does not show up on x-rays. In the normal hip this “joint space” is approximately 1/4 inch wide and fairly even in outline.

                                             

Normal Cushion, coverings and ligaments of Hip Joint

                
         
Fracture of hip Joint at neck of Femur bone             

  Hip joint replacement

                                                            

             A hip prosthesis is surgically implanted to replace damaged bone within hip joint. Hip joint replacement is a surgery also called Hip arthroplasty; Total hip replacement; Hip hemiarthroplasty-is to replace all or part of the hip joint with a prosthesis, an artificial device.

Complete hip prosthesis has three parts:
             A cup that replaces your hip socket. The cup is usually plastic, although some centers are trying other materials like ceramic and metal.
A metal or ceramic ball that will replace the fractured head of the thigh bone.
A metal stem that is attached to the shaft of the bone to add stability to the prosthesis.

                     

             Only head of the femur is replaced with prosthetic device hemi-arthroplasty whereas both head of the femur and corresponding socket is replaced in total hip replacement.

Evaluation
             Orthopedic surgeon after evaluation of all your medical records relating to the hip joint and heart and lung functions will suggest type of procedures and type of anesthesia. Anesthesia can be complete general anesthesia or only spinal anesthesia.

Necessity of hip replacement
             This procedure is indicated mainly for patients of age 60 and above. For younger people hip resurfacing is preferred. Indications for replacing the hip joint include:
1) Severe arthritis pain that limits a person's ability to do the things they want to do
2) Fractures in the elderly of the neck of the femur (usually requires a hemi-arthroplasty)

Hip joint tumors
Contra indications
Current hip infection
Extreme obesity (weight over 300 pounds)
Nerve disease affecting the hip
Paralyzed quadriceps muscles
People with poor skin coverage around the hip
Serious physical disease (terminal disease, such as metastatic cancer)
Those with severely limiting mental dysfunction
Very young patients

Risks
Blood clots in the legs (deep vein thrombosis), which can break free and move to the lungs (pulmonary embolus)
Dislocation of the artificial hip
Extra bone growth that can cause stiffness
Infection that requires removal of the artificial hip
Pneumonia

Surgery
             The orthopedic surgeon makes a surgical cut, often over the buttocks, to expose the hip joint. The head of the thigh bone is removed and removed. Then, the hip socket is cleaned out and a tool called a reamer removes all of the remaining cartilage and arthritic bone.
             The new socket is implanted, after which the metal stem is inserted into the thigh bone. The artificial components are fixed in place, sometimes with special cement. The muscles and tendons are then replaced against the bones and the surgical cut is closed.
A small drainage tube will be placed during surgery to help drain excess fluids from the joint area. Many surgeons also place a knee immobilizer or special pillow between the legs in the operating room to prevent the hip from dislocating.
             Moderate to severe pain is expected after surgery. However, you will receive painkillers for the first day or more after surgery. Painkillers may be given through a vein through the spinal cord (an epidural), or by way of a special patient-controlled analgesia (PCA) device.
The pain should gradually decrease, and by the third day after surgery, painkillersk, taken by mouth, may be sufficient to control your pain. Try to schedule your pain medications about 30 minutes before walking or changing position.
             You will also return from surgery with several IV lines in place to provide fluids and nutrition. The IV will remain in place until you are drinking adequate amounts of fluids.
             If the procedure is elective (planned in advance rather than in response to an injury), you can donate blood several weeks prior to surgery to replace any blood lost during the procedure.
Sometimes, the blood that is drained from the wound during surgery is collected in a special sterile container to be reinfused through an IV after surgery.
Wearing special stockings or inflatable compression stockings, which are used to reduce your risk of developing blood clots may be necessary . Blood clots are more common after leg surgery.
             Surgeon will advise moving and walking early after surgery. On the first day after surgery, you should get out of bed to a chair. When in bed, perform ankle exercises frequently to prevent development of blood clots.
A Foley catheter may be inserted during surgery to monitor your kidney function and fluid level. It will be removed after surgery. You will be encouraged to try to walk to the bathroom with assistance.

X ray picture after Hip Replacement.
                                                                                                                                  

Outlook
The results are usually excellent. The operation relieves pain and stiffness, and most patients need no help walking.
Post operative period
             You will remain in the hospital for 3 to 5 days after surgery. However, some people may need to stay temporarily at a rehabilitation unit or long-tern care center until mobility has improved and they are safely able to live independently. These centers will provide intensive physical therapy to assist you in regaining muscle strength and flexibility in the joint.
             Be careful after surgery that you don't dislocate the artificial hip. The new hip will not have the same range of movement of the original joint, although you should eventually be able to return to your previous level of activity. While you should avoid vigorous sports such skiing or contact sports, many people go on to play tennis and golf quite successfully.
The use of crutches or a walker may be necessary for as long as 3 months, although most people who did not use them before are able to walk without them in several weeks.
             Many surgeons place their patients on blood thinners for several weeks after surgery to help prevent blood clots. These may be taken in the form of pills (either Coumadin or aspirin) or injections.

Points to keep in mind
The new joint has a limited range of movement. You will need to take special precautions to avoid displacing the joint, including:
Avoid crossing your legs or ankles even when sitting, standing, or lying.
When sitting, keep you feet about 6 inches apart.
When sitting, keep your knees below the level of your hips. Avoid chairs that are too low. You may sit on a pillow to keep your hips higher than your knees.
When getting up from a chair, slide toward the edge of the chair and then use your walker or crutches for support.
Avoid bending over at the waist. You may consider purchasing a long-handled shoehorn or a sock aid to help you put on and take off your shoes and socks without bending over. Also, an extension reacher or grabber may be helpful for picking up objects that are too low for you to reach.
When lying in bed, place a pillow between your legs to keep the joint in proper alignment.
A special pillow or splint may be used to keep the hip in correct alignment.
An elevated toilet seat may be necessary to keep the knees lower than the hips when sitting on the toilet.

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