The hip is a ball and socket joint. The ball portion of the joint is called the femoral head, and is part of the upper leg bone (femur). The socket portion is called the acetabulum, and is part of the pelvic bone. The femoral head (ball) fits into the acetabulum (socket) and moves within its natural fluid, called synovial fluid, which helps to lubricate the joint during motion
In a healthy hip joint, the surfaces of these bones where the ball and socket rub together are very smooth and covered with a tough protective tissue called cartilage. Arthritis causes damage to the bone surfaces and cartilage. These damaged surfaces eventually become painful as they wear.
There are many ways to treat the pain caused by arthritis. One way is total hip replacement surgery. The decision to have total hip replacement surgery should be made very carefully after consulting your doctor and learning as much as you can about the hip joint, arthritis, and the surgery.
In total hip replacement surgery, the ball and socket that have been damaged by arthritis are removed and replaced with artificial parts made of metal and a durable plastic material. We call these artificial parts "implants," or "prostheses." During Surgery
The patient is first taken into the operating room and given anesthesia. After the anesthesia has taken effect, the skin around the upper thigh is thoroughly scrubbed with an antiseptic liquid. An incision of appropriate size is then made over the hip joint.
BENEFITS OF MINIMALLY INVASIVE TOTAL HIP REPLACEMENT
MIS - THR
The Mini-Incision hip replacement offers significant potential advantages over traditional hip replacement:
Smaller incision and scar--one incision as small as 3 â€“ 5 inches in length, rather than the standard 10 â€“ 12 inches incision.
Shortened hospital stay--possibly three days versus four and a half or more.
Little blood loss ( usually no blood transfusion is required for a primary THR.
These benefits may allow a quicker return to work and daily activities.
To diagnose your condition, an orthopaedic surgeon will perform a thorough examination of your hip, analyse x-rays, and conduct physical tests. You will be asked to describe your pain, if you suffer from other joint pain, and if you have endured past injuries that may have affected your current hip condition.
Your joints will then be tested for strength and range of motion through a series of activities, which include bending and walking. X-rays of your hip joint will indicate any change in size, shape or unusual circumstances. Replacing the Socket Portion of the Joint
One type of implant that replaces the socket consists of a metal shell that is lined with a strong plastic liner.
Removing the Surface of the Socket
The leg is manoeuvered until the femoral head is dislocated from the socket.
A special reamer is then used to remove the damaged cartilage and bone surface from the acetabulum, and to shape the socket so it will match the shape of the implant that will be inserted.
Inserting the Implant
The shell portion of the socket implant may be attached either by using a special kind of epoxy cement for bones, or by pressing the implant into the socket so that it fits very tightly and is held in place by friction. Some implants may have special surfaces with pores that allow bone to grow into them to help hold the implant in place. Depending on the condition of the patient's bone, the surgeon may also decide to use screws to help hold the implant in place.
When the shell portion of the socket implant is in place, the plastic liner is locked into place inside the shell. Replacing the Ball Portion of the Joint
The implant that replaces the ball consists of a long metal stem that fits down into the femur. The metal ball is mounted on top of this stem.
Removing the Ball
A special power saw is used to remove the damaged femoral head.
Clearing and Shaping the Canal
The upper leg bone has relatively soft, porous bone tissue around the center. This part of the bone is called cancellous bone. It surrounds the canal, which mainly contains blood vessels and fatty tissue.
Special instruments are used to clear some of the cancellous bone from the canal, and then to mold the inside walls of the canal to fit the shape of the implant stem.
Inserting the Implant
The stem implant may be held in place by either using the special cement for bones, or by making it fit very tightly in the canal. If cement is used, it is injected into the canal first, and then the implant is inserted into the canal. If cement is not used, the implant is simply inserted into the canal. Like the socket implant, the stem implant may have a special surface with pores that allow bone to grow into them.
COMPLETED MIS TOTAL HIP REPLACEMENT SURGERY USING 10 CM INCISION
Closing the Wound
When all the implants are in place, the surgeon places the new ball that is now part of the upper leg bone into the new socket that is secure within the pelvic bone. If necessary, the surgeon may adjust the ligaments that surround the hip to achieve the best possible hip function.
When the ligaments are properly adjusted, the surgeon sews the layers of tissue back into their proper position. A plastic tube may be inserted into the wound to allow liquids to drain from the site during the first few hours after surgery. After the tube is inserted, the edges of the skin are sewn together, and a sterile bandage is applied to the hip. Finally, the patient is taken to the recovery room.
HEALED SKIN INCISION AFTER MINIMALLY INVASIVE TOTAL HIP REPLACEMENT
WHAT'S NEW IN TOTAL HIP REPLACEMENT SURGERY ?
ALTERNATE BEARING SURFACES FOR YOUNGER PATIENTS WITH ARTHRITIS / Avascular Necrosis ( AVN ) OF THE HIP JOINT Minimally Invasive Hip Resurfacing/ Replacement Surgery
Removes only unhealthy bone and replaces it with a metal on metal articulation.
It preserves the normal bone of the hip â€“ patients can squat, sit cross-legged without the risk of dislocation.
Everlasting - based on 35-year history in Birmingham of metal on metal implants.
Excellent restoration of full function.
Femoral head remains viable after BHR surgery.It does not sacrifice normal bone during primary surgery.
Activity restriction not required after surgery, as there is hardly any risk of dislocation.Patient can indulge in full sporting activities without risk of dislocation. Patients have gone back to sports like competitive Judo and Squash after surgery.
Overall 99% success rate - ideal option for the younger or more active patient.
BILATERAL HIP ARTHRIRTISAFTER BILATERAL HIP RESURFACING
BILATERAL AVN OF HIPAFTER METAL ON METAL HIP REPLACEMENT
Surface Replacement of the Hip
Surface replacement of the hip and shoulder ball, procedure is a recent alternative for patients, who may have once been considered for a traditional total hip replacement (THR). Up to the present time patients with arthritis of the hip and Avascular Necrosis (AVN) have hip replacement after 50yrs of the age. Hip replacement is an excellent operation for patients over 55 yrs of age.
The hip resurfacing procedure is ideal for patient below 50yrs to 55 years of age with more active lifestyles.
Surface Replacement of the hip is a procedure where only the diseased surface of the hip balls is covered by a cap. The surfaces of the head (ball) of the femur and acetabulum (cup) are replaced and the femoral head is reshaped instead of removed. The articulating surfaces, (the surfaces that rub together) are very highly polished metal. Metal articulations have been proven for many years to be a very low wearing surface and excellent mobility.
The new technology can benefit certain patients far more than the traditional hip replacement, allowing them the option to be active once again.
Surface Replacement is a great boon to young& middle aged patients with active life style. Surface replacement offers patient the opportunity to preserve the maximum amount of natural bone stock. The benefit of Surface Replacement is many-fold:-
Femoral head is preserved
Femoral canal is preserved and no associated femoral bone loss with future revision. Also, the risk ofmicrofracture of femur with uncemented stem implantation is eliminated.
Larger size of implant "ball" reduces the risk of dislocation significantly
Stress is transferred in a natural way along the femoral canal and through the head and neck of the femur. With the standard THR, some patients experience thigh pain asthe bone has to respond and reform to less natural stress loading.
Use of metal rather than plastic reduces osteolysis and associated early loosening risk.
Use of metal has low wear rate with expected long implant lifetime.
MINIMALLY INVASIVE HIP RESURFACING
Alternate bearing surface for younger patients with Arthritis / A vascular Necrosis (AVN) of the Hip Joint. Conventional Polyethylene bearing surfaces undergo wear & tear as the metal head moves against the plastic in the replaced hip joint. This gives rise to small Polyethylene particles which produce a reaction in the body tissues which leads to loss/weakening of the bone. This leads to bone loss, loss of fixation of the implants & ultimately failure of the hip joint.
As a younger patient is more active, conventional polyethylene implants fail earlier in the young & active patients. Hence, the need for an alternate bearing surface for these patients. Some of these bearing surfaces have been around for quite some time and now have been improved further due to excellent metallurgical processes. They have shown very good, long term survivorship in these young patients. Some of the available alternate bearing surfaces are:
A. Ceramic on ceramic articulation:
Articulating surfaces made of aluminium oxide ceramic.
Smaller debris than metal on polyethylene.
Surfaces have high wettability Reduces friction in the joint.
B. Metal on metal:
Large diameters of femoral head and cup components- low friction.
Less wear compared to metal on polyethylene- Lower failure rate.
C. Highly cross linked polyethylene:
Cross linking of polyethylene by gamma radiation reduces oxidation of polyethylene.
The process decreases wear tenfold compared to standard polyethylene.
D. Vitamin E infused poly:
Polyethlene oxidation is like rust on a car which can weaken the polyethylene.
Vitamin E has antioxidant properties and when added to polyethylene, increases its wear resistance.