HIP REPLACEMENT
- /HIP REPLACEMENT
Total Hip Arthroplasty
Arthroplasty is an operation to restore motion to a joint and Function to the muscle, ligaments and other soft tissue structures that control the joint.
Total Hip Arthroplasty is the most commonly performed adult reconstructive hip procedure. It converts the painful, stiff diseased hip into painless mobile and biomechanically stable hip.
Total hip arthroplasty is done for advanced stages Osteoarthritis, Rheumatoid arthritis, Osteonecrosis of the femoral head, Ankylosing spondylitis, Nonunion fracture neck of femur, and many other disorders.
In advanced stages of the disease, the patient is almost bedridden and life becomes crippled and miserable. Total hip arthroplasty has proved a boon for such patients
Goals of surgery are to-
i) Relieve pain
ii) Provide motion with stability
iii) Correct deformity
Father of modern Total Hip Arthroplasty, Professor Sir John Charnley is credited as the seminal contributor with his monumental work on low friction arthroplasty representing the basis of most current implant design.
Anatomy :-
– Hip is a major weight bearing joint of the body, its normal function is necessary to carry out smooth day to day activities.
– The hip joint is a ball and socket type of joint. The inherent congruity of articular surfaces and surrounding strong ligaments makes it a very stable joint
– The articular ends of the femoral and acetabular cup are covered with smooth cartilage. The joint is lined by the synovial membrane from inside which secretes the synovial fluid essential for the lubrication of joint.
– Hip is surrounded by ligaments which are the strongest ligaments in our body.
Common Pathologies
1) Osteonecrosis / Avascular necrosis of femoral head-
This condition is quite common in indsa age is this disease but average age group 3 and 4 decade of life. In simple language Avascular necrosis (AVN) Is the cellular death of the femoral head bone cells due to blockage bland supply
Maximum blood supply to the femoral head comes from the femoral side and very lats from acetabula: side So any disease which blocks the vessels coming from the tomoral side will load to the cellular death and start of surfaces AVN Slowly the articular Its sphericity and the joint becomes artivitc.
In our countries consumption of alcohol stencia intaka, Ever disease and sometimes Idiopathic (without any reason) causes of this disease.
2) Rheumatoid Arthritis:-
This is primarily inflammatory arthritis. The discase pathology les the synovial membrane. The diseased mensbrane farther damages the joint.
3) Post-traumatic Ostecarthritis :-
Previously mal-united fermone fractures result in deformed alignment. The forces passing in abnormal fashion damage the joint further leading to osteoarthritis
4)Intra capsular fracture neck of fomur-
When the fracture occurs inside the joint sapsule, many times it results intu AVN of the tomoral head. These factures should be fixed on an emergency basis
5) Childhood diseases –
Many childhood diseases like Developmental dysplasia of hip or slipped capital femoral epiphysis results in hip joint antivibis in adult life.
Total Hip Arthroplasty/Total Hip Replacement
There are other surgical options which were tried in past and may be tried today
i )Arthrodesis – can be considered young vigorous patient with the unilateral hip disease. It provides stabilty at the cost of mobility.
ii) Excision Arthroplasty –provides mobilty at the expense of stability.
iii) Subtrochanteric varus or valgus osteotomy – can be considered for the young patient with arthritis if the joint is not grossly incongruous and with a fair degree of active motion.
iv) Core decompression – can be done in early stages of avascular necrosis of femoral head to relieve pain. Every above-mentioned surgery has its own merits and demerits and reserved for specific indications.
Let’s see Total hip replacement Technique –
– In total hip arthroplasty, the femoral head is cut through the neck. Femoral canal is opened and artificial femoral stem prosthesis is inserted in. The head is replaced by a metal or ceramic component.
– There are different techniques and ways as for how to fix this stem inside the bony canal.
– Acetabular or cup side as well is done same. The acetabular cavity is sequentially reamed and the dead loose cartilage flaps are removed. New artificial cup is fitted inside this cavity
Types of hip replacement surgeries:
1. Cemented THR
In this type, we fix the component to the bone with the help of cement. Both the acetabulum and femoral stem can be fixed with cement.
There is a lot of improvement in the quality and characteristic of bone cement, and also in the handling of cement. Now we have a newer generation cementing technique which will help to improve the longevity of the surgery.
We prefer cemented hip replacement for the older patients and for patients having osteoporotic bones.
2. Uncemented THR
This is the commonest type of total hip surgery done at our center. In this case, cement is not used for the fixation. Rather the fixation relies upon the perfect sizing and fitting of the components. The surfaces of the endoprosthetic component are either plasma sprayed or blasted or covered with hydroxyapatite. These all will help to grow the bone over the surface and in term help to have a firm bond between the artificial implant and the bone.
We generally do this type of surgery in the young patient and for patients having good bone stock.
Hybrid total hip arthroplasty Combination of one cemented and one uncemented component will result into hybrid total hip arthroplasty.
3. Hybrid total hip arthroplasty
Combination of one cemented and one uncemented component will result into hybrid total hip arthroplasty.
– Bearing surfaces
On the femoral head side, we have an option of metal, oxonium or ceramic head. Both these options come in different sizes as 22.22, 28, 32, 36 mm.
Larger the head better more will be movement possible and more will be the stability.
Similarly, on the acetabular side we have Cross linked poly, Highly cross linked poly, vitamin E mixed poly, ceramic liner or metal liner. So accordingly we can have Metal on Poly (MOP), Ceramic on Poly (COP), Ceramic on ceramic (COC), or Metal on metal (MOM) options with us.
Each one has merits and demerits. Ceramic has less wear rate and so may last longer but are brittle. Metal is strong but may have more wear rate.
Complications Of Surgery
Knee replacement is a major surgery and not without complications and risks.
There can be complications during the surgery, in early post operative period and late post operative period. Of course, every single precaution to avoid it is the key but it’s important to be aware of it and to seek timely medical attention.
1. Infection:
One of the dreadful complications is an infection. Its incidence is low and average percentage is less than two. It can be acute, (can occur while in the hospital or after you go home). Or it can be late or secondary (infection spread through the bloodstream from any other focus in your body).
We take maximum preventive measure for that. It starts from your preoperative preparation. Thorough check up is done to rule out any infection focus in your body. Even dental caries, ear infections, skin infection or urine infections can be the serious concern.
The patient is at high risk for infection when the immunity is at compromise, like a patient on immunosuppressant, steroid, or low protein and albumin levels. Rheumatoid patients, anemic patients are also at little higher risk.
-In the operation room, we take enough precautions. This operation should be done in the state of art operation room (which has a laminar flow system.
-Operation team wears disposable gowns and space suits.
-Prophylactic antibiotics are used.
If unfortunately, the infection spreads in the surgical site then within two weeks re exploration, lavage, exchange of poly and intravenous antibiotics can help.
If it happens after a long time the surgeon has to take out the implant, put a spacer till the infection gets under control and second surgery of re implantation after wards can be done.
2. Deep vein thrombosis:
Blood clots may form in the leg and calf veins. It can be dangerous if the clot gets dislodge and travel to lungs.
We take enough precautions to prevent this:
- Early weight bearing and calf exercises are started on the same day.
- Mechanical compression devices are given along with. We also use a blood thinner injections/tablets for about 2 to 3 weeks.
- Anti embolic stockings is given to the patient for use up to 6 weeks after the surger
3. Leg-length Inequality:
Sometimes after a hip replacement, one leg may feel longer or shorter than the other. Your orthopedic surgeon will make every effort to make your leg lengths even but may lengthen or shorten your leg slightly in order to maximize the stability and biomechanics of the hip. Some patients may feel more comfortable with a shoe lift after surgery.
4. Dislocation:
This occurs when the ball comes out of the socket. The risk for the dislocation 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.
Other Complications
1. Superficial/cutaneous nerve damage:
Cutaneous nerves supplying the skin over the incision site are usually damaged. They are very insignificant but may cause numbness around the wound for some time. Of course, it does not affect your course of physiotherapy after the surgery.
2. Loosening and Implant Wear:
Over years, the hip prosthesis may wear out or loosen. This is most often due to everyday activity. It can also result from a biologic thinning of the bone called osteolysis. If loosening is painful, a second surgery called a revision may be necessary.
Cases:
Case 1: Preoperative
Case 1: Postoperative
Case 2: Preoperative
Case 2: Postoperative
Case 3: Preoperative
