Total Hip Replacement


Hip Replacement

Dr. Charnley who is also known as the father of hip replacement surgery, propounded the basic principles of this surgery. His and other pioneer surgeons’ successful results have made this procedure evolve into what some people say as the invention of the century


What is Total Hip Replacement?

Hip replacement is a very common procedure, typically performed on patients affected by osteoarthritis (the gradual depletion of cartilage on the surface of the joints). Rheumatoid arthritis, osteonecrosis, injury, and other conditions can also necessitate hip replacement. Symptoms of hip arthritis are often characterized by aching pains in the hip that can be chronic or only occur occasionally. The pain from hip arthritis can sometimes also spread to the groin, thigh, buttock, and perhaps even the knee. .

Walking can sometimes become difficult with more pronounced pain from hip arthritis, and may ultimately cause one to require a cane or walker for better mobility. Less invasive treatment for hip arthritis can include over-the-counter anti-inflammatory medications and/or physical therapy. For more advanced cases, surgery can be performed. Depending on the extent of the condition, surgery can include relatively minimally-invasive procedures such as smoothing of the joints or re-alignment of bones. More severe cases may require hip replacement surgery. The procedure involves removal of the top of the femure (thighbone) and using artificial implants to replace of the “ball-and-socket” mechanism of the hip. Hip replacement can be performed as a minimally invasive procedure, using only one or two small incisions. This typically allows patients to have an easier and quicker recovery process. Some hip surgeries can be performed as an outpatient; however, more invasive procedures often require a hospital stay

Condition Where THR is Useul?

The most common indications are avascular necrosis of the hip, osteoarthritis (O.A) and Rheumatoid arthritis (R.A).In additional may be useful in certain fracture dislocations. Osteoarthritis (O.A) is a wear and tear disease where wear and tear leads to gradual thinning of cartilage. This thinning of cartilage can be seen on an X-ray as reduced Joint space.

The symptoms of O.A are gradual reduction in the distance that a person can walk over the years due to increasing pain. The ability to stand also gradually declines– people will usually answer it as 20 min 30 min before it forces them to find a chair to sit. Climbing stairs also becomes difficult. O.A could be primary or secondary to previous trauma such as a fracture in the acetabulum which has not been adequately managed resulting in accelerated wear of cartilage.

 

Rheumatoid arthritis is a autoimmune disorder where patients forms antibodies against self resulting in damage to cartilage. Other conditions such as psoriatic arthritis, SLE and some common autoimmune conditions can also lead to similar picture. Another condition where it is useful is bone tumors especially in limb salvage surgeries to avoid amputations.

What are the type of Implants?

 

Broadly there are two basic types of implants

Hip resurfacing where only the affected articular surface of the hip is excised leaving the neck of femur intact.

Total Hip replacement-Here the total hip is replaced and the femoral neck is cut from base. In a total hip replacement surgery, the painful parts of the damaged hip are replaced with artificial hip part called prosthesis.

The prosthesis consists of a socket, ball, and stem. The outer shell of the socket is usually made of metal and the inner shell consists of plastic, or the entire socket may be plastic. When the ball moves inside the socket, it mimickers the natural movement at hip allowing for smooth, movement like a natural hip.

 

 

 

 

What is cemented or cementless?

Based on how the implants are fixed to the bone they can also be classified as cemented or cementless. Cemented

Fixed bearing Here a type of bone acrylic cement is used to fix implant components to the bone.

 

 

 

 

 

 

Cement less In other cases, the implants may be “press-fit” into the bone. Press-fit components may have a special porous coating that allows bone tissue to grow up to it for fixation. The cemented implants are usually reserved for elderly population undergoing THR while cementless variety is used for young population(Less then 60 years)

 

 

 

Are there alternate bearing surfaces for the hips

Yes, the routine femur head is made of modified cobalt chromium molybdenum alloy. The most common bearing surface used is metal on poly. Compared to metals ceramics are harder and less likely to develop scratches. This means lower wear and longer life for the hip. Ceramics however have been associated with fracture and squeaking. Oxidized Zirconium (a form of ceramic) hips have been present for some time and are supposed to prolong implant survivorship. The risk of fractures associated earlier has not been noted in these surfaces. In addition metal on metal bearings are there. The issue with them is a risk of cancer that has been noted in mice. However no cases have been noted in the human. It should be avoided in young females wishing to get pregnant because of risk of teratogenesis. Allergy may also be a factor in these implants in a small number of cases.

What is multimodal analgesia ?

Multimodal analgesia refers to using a combination of pain relieving agents to achieve best results. In my practice we use a intraarticular injection of cocktail of drugs .The surgeries are done under spinal or combined spinal epidural. The epidural is usually removed immediately after surgery.

When can I stand and go to toilet myself?

Most of the patients are mobilized within 12 – 18 hours after surgery. They can go to a western style toilet after 24-48 hrs after surgry and are usually home on 3rd to 4th postoperative day.

When can I climb stairs?

If you have undergone only one hip than stair climbing is allowed 3rd day after surgery. If both the hips are done than stair climbing is started after 6 weeks

When can I drive a car/vehicle?

Car or Vehicle driving is allowed after 4-5 weeks

How much can I walk after THR?

You are allowed to walk as much as you can. Many of my patients who were avid morning walkers routinely walk 3-5 Kms daily. The general medical health of the patients (cardiac and lung status) is the limiting factor not the knee. Typically, patients are advised to avoid high impact sports such as jogging, basketball, racquetball, gymnastics, etc. Safer activities may include walking, golf, swimming, and bicycling.