Introduction

THE HIP JOINT :

The hip joint comprises of a long thigh bone articulated with cup shaped cavity of hip bone.Rounded head of the thigh bone fits into the cavity to from a ball and socket joint.

The surface of the head of the thigh bone and the socket are covered by specialised tissue called articular cartilage.

The joint cavity is lined by a membrane called the synovium which secretes synovial fluid into the joint and allows smooth movement of the ball within the socket.

PROSTHESIS OF HIP JOINT :

The doctor will decide about the best material to be used in your particular case. This selection will depend upon factors such as –

• You’re age
• Normal level of Activity
• Degree of damage
• Deterioration of bones of your Hip Joint

Although a replaced hip joint may continue to function successfully for 15 yrs. or more, it will not last forever. Careful consideration is therefore necessary before replacing the hip of someone in their forties or fifties, as they are likely to require revision surgery in future. In such conditions cementless prosthesis may be most appropriate.

Femoral Component :

Femoral component prosthesis replace the head of the femur. It contains ball shaped head & a stem which is inserted into the shaft of femur.

Femoral component is made of a variety of metals

• Stem :
  • Cemented Stem : Cemented Stem is made from steel, titanium & titanium alloys and is highly polished. It is fixed with the help of cement in femoral shaft.
  • Uncemented Stem : Uncemented Stem is coated with Hydroxyapatite or is porous coated. It fixes into femoral shaft. These allow bone to grow onto their surface.
• Head :
  Head is fixed on neck of stem & acetabulum component. It is made of any one of the following metals. –

  
  

  • Cobalt Chrome : It is a very strong alloy having high resistance to wear & corrosion.
  • Oxidized Zirconium : It is toughest metal known today. It is also having high resistance to wear & corrosion.
  • Ceramic : Ceramic cornponents are brittle but hard which do not scatter easily, are durable & have low friction. These are particularly good in young active people.
• Acetabular Component :
  • Uncemented : It consists of a shell & a liner. The shell is made of titanium alloy, which allow bone to grow easily onto its surface. These have good press fit design. The liner is made of highly cross linked polyethylene and has very good wear properties.
    Ceramic liners are also available, and are durable & have low friction.
  • Cemented : Cemented components are made of highly cross linked polyethylene and have very good wear properties.
    
  • There are several diseases which can damage the knee or hip joint as well as other joints of the body also. These diseases cause damage to the surfaces of the bones taking part in the joint formation resulting in severe pain and disability.

    OSTEOARTHRITIS :

    Osteoarthritis is the most common cause for destruction of most of the joints of the body including the knee & hip joint. As the age progresses the cartilages over the ends of bones degenerate due to friction caused by the use of the joint. Once the cartilage is lost the surface of the bones beneath gets exposed. Due to the continuous rubbing and friction while walking the surface of the bone gets worsened and the individual cannot take even a single step without pain. Osteophytes formed at the margins of the joint restrict the movement of the joint. Due to severe pain and destruction of the joint one may start limping while walking and that will cause problems to the spine.

    For management of osteoarthritis one may use cane for support while walking, physiotherapy and take pain killer tablets or intra- articular injections.

    RHEUMATOID ARTHRITIS :

    Rheumatoid arthritis is a disease of connective tissues which involves inflammation of several joints. It starts in early age and can affect both men and women, more often women. The affected joints become swollen and tender. The bones become demineralised and muscles weak and atrophied.

    The cause of all types of osteoarthritis is not always known.Some people suffer from haemophilia which is a bleeding disorder in which repeated bleeding into the joint results in swelling and inflammation, with subsequent destruction of the articular cartilage. Infection of the joint , accidental injury, gout, death of the tissue of the bone due to alcoholism, long term use of steroids or pain killers are some of the known causes. Some people suffer from dislocation of the hip joint right from birth which puts pressure on the joint causing excessive wear and tear of the joint.

    These are some common complications associated with each type of surgery & some are specifically related to hip replacement surgery. Most complications are minor but it is important to be aware & to seek medical attention.

    1. Chest InfectionPossible following general anaesthesia and particularly in smokers.
       • Deep breathing is important
    2. FeverIt can develop in the first 24-72 Hrs.after surgery.Its cause will have to be investigated and treated accordingly.
    3. Thrombosis & EmbolismAfter surgery blood clot (deep vein thrombosis) may occur in one of the deep veins of the body.
       • We take precautions to prevent this from happening.
         • Wearing Anti-Embolism stockings : at least for 6 weeks.
         • Course of blood thiner Injections/Tablets.
         • Exercises & Early Mobilization after surgery.
    4. InfectionIt is always a risk when materials are implanted into the body.

       

       • We use special precautions to avoid this
         • Operation theaters with laminar flow.
         • Operating Staff with disposable suits. (Space Suits)
         • Antibiotics in peri operative period.

       
       

    5. SepsisSepsis may be caused by pus producing organisms. Main cause is contamination of the wound.
       • You need to take proper medical advice if you have pain, swelling, heat and redness around wound or with leakage of pus and high fever.
    6. Nerve DamageThe small nerves supplying the skin over operation site are usually damaged. When an incision is made during surgery it can cause numbness around wound. This does not in any way affect the function following surgery
    Apart from above complications following complications are specifically related to hip replacement surgery –
    1. Dislocation
       It involves complete displacement of the head of the femur from acetabulum. It is not common complication.

       
       

       • Patient needs to take precautions as advised by the surgeon.
    2. Aseptic Loosening
       Most common cause of component failure may be because of poor quality bone, excessive body weight, improper or excessive activity.
    3. Fracture of femur around an implanted stem is a serious complication. Sometimes implant loosening associated with osteolysis weakens bone stock & may predispose to fracture.
    After your decision to go in for a joint replacement you should be aware of the basic things to be done before surgery. Such as –
    • Suitable prosthesis for you.
    • The cost of your prosthesis.
    • Total Hospital stay & cost of hospital stay.
    • The Blood, Heart and Chest investigations.
    • Get this investigations 2-3 weeks before the date of surgery & get them checked by a physician.
    • It is necessary to confirm that there is no active infection in your body.
    • If you have mediclaim facility, you should contact hospital’s mediclaim department at least one week before surgery with your policy documents.
    • You should show the drugs which you are already taking. Some types of medicines like steroids & blood thinning medicines are to be stopped 5-7 days prior to surgery.
    • For admission in hospital take admission letter from your surgeon.
    • You may advised to get admitted 1-2 days prior to the surgery. Take all investigations report, previous medical records & drugs with you.
    AFTER ADMISSION:

    After you are admitted in the hospital, a resident / registrar doctor will come to you. He will examine you again & explain you in brief things to be carried out before & after the operation. A physician will come & examine you & will give the fitness for surgery.

    ANAESTHETIST VISIT:

    Anaesthetist will come to you & will examine you from the view of anesthesia. He will explain to you in brief the type of anaesthesia, drugs to be stopped & the drugs to be taken on the day of surgery. You will be asked to stop taking food or drinks at least 6 – 8 hrs. before surgery.

    ANAESTHESIA:

    Anaesthesia will be spinal & epidural in which the lower part of your body will be anaesthetized. You will be awake during surgery. A thin plastic tube will be inserted into your back through which anaesthetic drug along with pain killers will be induced in your body. Because of this you will feel numbress in your legs. This tube may kept in your back for couple of days for pain relief.

    BATHING:

    You will be asked to have bath on the previous night of surgery & a couple of hours before surgery, to maintain cleanliness of your body & operation site.

    AFTER YOUR OPERATION:

    After surgery you will be kept in the recovery room for couple of hours. After that you will be shifted to your room. You will be asked to keep fasting for 4-6 hrs. after surgery. After that you can start orally with clear liquids first. If there is no vomiting, you can have a light diet on the night of surgery.

    DRIPS:

    There may be an intravenous drip for next 2 – 3 days for admission of antibiotics, saline & fluids. Once you will start taking food orally, saline & fluids will be discontinued but antibiotics will be continued for the next couple of days.

    WOUND DRAINS:

    There may be one or more small plastic tubes extending out of the side of the wound dressing, draining into a bottle. These tubes enable excess fiuid & blood to drain away from the wound. Dressing will be checked & changed as required. Pillow will be given under calf to avoid pressure sores.

    SIMPLE EXERCISES:

    You are advised to do some simple exercise before & after operation. You should start them as soon as possible when you are still in recovery room or shifted to your room.

    • Deep Breathing – Deep breathing and coughing will help to keep your lungs supplied with oxygen & clear the sputum.
    • Leg Execises – Simple leg exercises will help to reduce risk of deep vein thrombosis & can easily be done. Some of them will also help mobilize your hip joint & strengthen your muscles.
      • Foot Flexion & extension & circular movements. (fig. 1)
      • Lying on your back, press your kness on to the bed with your leg straight. (fig.2)

    
    

    
    

    PAIN RELIEF :

    If you have had an epidural anaesthesia, pain killer drug may be infused through it.

    After first couple of post operative days, regular pain killers will probably provide sufficient pain relief, likely to be continued for several weeks to enable you to do necessary exercises.

    In hospital, if your pain is not being controlled kindly inform a doctor or nurse, as it may be possible to give you stronger pain killers.

    THROMBOSIS PREVENTION :

    Blood clots are most common about 2 days after surgery. Although they can develop any time upto 3 weeks later.

    • Prevention –
      • Daily injection of low dose anti-coagulant or tablet until you are in hospital.
      • You will be asked to wear anti-embolism stockings for upto 6 weeks after surgery.

    BLOOD TEST :

    A sample of your blood will be taken to measure hemoglobin level. If hemoglobin is low –

    • May be started on iron tablets.
    • Sometimes blood trans fusions are required.

    X-RAYS :

    An x-ray will be taken of your operated joint, either in the recovery room or within 48 hrs. after operation.

    BLADDER FUNCTION :

    You will have a urinary catheter that will drain your urine from your urinary bladder. It will kept there for the next 3-4 days until you are able to urinate voluntarily in a bed pan or commode-chair near bedside.