Replacement joint
Encyclopedia
Replacement arthroplasty [from Greek arthron, joint, limb, articulate, + -plassein, to form, mould, forge, feign, make an image of], or joint replacement surgery, is a procedure of orthopedic surgery
in which the arthritic or dysfunctional joint
surface is replaced with an orthopaedic prosthesis. Joint replacement is considered as a treatment when severe joint pain or dysfunction is not alleviated by less-invasive therapies.
Joint replacement surgery is becoming more common, with knees and hips replaced most often. As of 2009, about 773,000 Americans have a hip or knee replaced each year".
with artificial joints in 1939. By 1948,
he was at the New York Orthopedic Hospital (part of the Columbia Presbyterian Medical Center) and with funding from the Office of Naval Research
, was replacing hip joints in humans.
Two previously popular forms of arthroplasty were: (1) interpositional arthroplasty, with interposition of some other tissue
like skin
, muscle
or tendon
to keep inflammatory
surfaces apart and (2) excisional arthroplasty in which the joint surface and bone were removed leaving scar
tissue to fill in the gap. Other forms of arthroplasty include resection(al) arthroplasty, resurfacing arthroplasty, mold arthroplasty, cup arthroplasty, and silicone replacement arthroplasty. Osteotomy to restore or modify joint congruity is also a form of arthroplasty.
In recent decades the most successful and common form of arthroplasty is the surgical replacement
of a joint or joint surface with a prosthesis
. For example, a hip joint that is affected by osteoarthritis may be replaced entirely (total hip arthroplasty
) with a prosthetic hip. This procedure involves replacing both the acetabulum (hip socket) and the head and neck of the femur
. The purpose of doing this surgery is to relieve pain, to restore range of motion and to improve walking ability, leading to the improvement of muscle strength.
Pre-operative planning requires accurate Xrays of the affected joint, implant design selecting and size-matching to the xray images (a process known as templating).
A few days' hospitalization is followed by several weeks of protected function, healing and rehabilitation. This may then be followed by several months of slow improvement in strength and endurance.
Early mobilisation of the patient is thought to be the key to reducing the chances of complications such as venous thromboembolism
and Pneumonia
. Modern practice is to mobilize patients as soon as possible and ambulate
with walking aids when tolerated. Depending on the joint involved and the pre-op status of the patient, the time of hospitalization varies from 1 day to 2 weeks, with the average being 4–7 days in most regions.
Physiotherapy is used extensively to help patients recover function after joint replacement surgery. A graded exercise programme is needed initially, as the patients' muscles take time to heal after the surgery; exercises for range of motion of the joints and ambulation should not be strenuous. Later when the muscles have healed, the aim of exercise expands to include strengthening and recovery of function.
There are many controversies. Much of the research effort of the orthopedic-community is directed to studying and improving joint replacement. The main controversies are
Orthopedic surgery
Orthopedic surgery or orthopedics is the branch of surgery concerned with conditions involving the musculoskeletal system...
in which the arthritic or dysfunctional joint
Joint
A joint is the location at which two or more bones make contact. They are constructed to allow movement and provide mechanical support, and are classified structurally and functionally.-Classification:...
surface is replaced with an orthopaedic prosthesis. Joint replacement is considered as a treatment when severe joint pain or dysfunction is not alleviated by less-invasive therapies.
Joint replacement surgery is becoming more common, with knees and hips replaced most often. As of 2009, about 773,000 Americans have a hip or knee replaced each year".
Background
Stephen S. Hudack, a surgeon based in New York City, began animal testingAnimal testing
Animal testing, also known as animal experimentation, animal research, and in vivo testing, is the use of non-human animals in experiments. Worldwide it is estimated that the number of vertebrate animals—from zebrafish to non-human primates—ranges from the tens of millions to more than 100 million...
with artificial joints in 1939. By 1948,
he was at the New York Orthopedic Hospital (part of the Columbia Presbyterian Medical Center) and with funding from the Office of Naval Research
Office of Naval Research
The Office of Naval Research , headquartered in Arlington, Virginia , is the office within the United States Department of the Navy that coordinates, executes, and promotes the science and technology programs of the U.S...
, was replacing hip joints in humans.
Two previously popular forms of arthroplasty were: (1) interpositional arthroplasty, with interposition of some other tissue
Biological tissue
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...
like skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
, muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
or tendon
Tendon
A tendon is a tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension. Tendons are similar to ligaments and fasciae as they are all made of collagen except that ligaments join one bone to another bone, and fasciae connect muscles to other...
to keep inflammatory
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
surfaces apart and (2) excisional arthroplasty in which the joint surface and bone were removed leaving scar
Scar
Scars are areas of fibrous tissue that replace normal skin after injury. A scar results from the biological process of wound repair in the skin and other tissues of the body. Thus, scarring is a natural part of the healing process. With the exception of very minor lesions, every wound results in...
tissue to fill in the gap. Other forms of arthroplasty include resection(al) arthroplasty, resurfacing arthroplasty, mold arthroplasty, cup arthroplasty, and silicone replacement arthroplasty. Osteotomy to restore or modify joint congruity is also a form of arthroplasty.
In recent decades the most successful and common form of arthroplasty is the surgical replacement
Replacement joint
Replacement arthroplasty [from Greek arthron, joint, limb, articulate, + -plassein, to form, mould, forge, feign, make an image of], or joint replacement surgery, is a procedure of orthopedic surgery in which the arthritic or dysfunctional joint surface is replaced with an orthopaedic prosthesis...
of a joint or joint surface with a prosthesis
Prosthesis
In medicine, a prosthesis, prosthetic, or prosthetic limb is an artificial device extension that replaces a missing body part. It is part of the field of biomechatronics, the science of using mechanical devices with human muscle, skeleton, and nervous systems to assist or enhance motor control...
. For example, a hip joint that is affected by osteoarthritis may be replaced entirely (total hip arthroplasty
Hip replacement
Hip replacement is a surgical procedure in which the hip joint is replaced by a prosthetic implant. Hip replacement surgery can be performed as a total replacement or a hemi replacement. Such joint replacement orthopaedic surgery generally is conducted to relieve arthritis pain or fix severe...
) with a prosthetic hip. This procedure involves replacing both the acetabulum (hip socket) and the head and neck of the femur
Femur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
. The purpose of doing this surgery is to relieve pain, to restore range of motion and to improve walking ability, leading to the improvement of muscle strength.
Indications
- OsteoarthritisOsteoarthritisOsteoarthritis also known as degenerative arthritis or degenerative joint disease, is a group of mechanical abnormalities involving degradation of joints, including articular cartilage and subchondral bone. Symptoms may include joint pain, tenderness, stiffness, locking, and sometimes an effusion...
(OA) - Rheumatoid arthritisRheumatoid arthritisRheumatoid arthritis is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks synovial joints. The process produces an inflammatory response of the synovium secondary to hyperplasia of synovial cells, excess synovial fluid, and the development...
(RA) - Avascular necrosisAvascular necrosisAvascular necrosis is a disease where there is cellular death of bone components due to interruption of the blood supply. Without blood, the bone tissue dies and the bone collapses...
(AVN) or osteonecrosis (ON) - Congenital dislocation of the hip joint (CDH)Dislocation of hipDislocation of the hip is a common injury to the hip joint. Dislocation occurs when the ball–shaped head of the femur comes out of the cup–shaped acetabulum set in the pelvis. This may happen to a varying degree. A dislocated hip, much more common in girls than in boys, is a condition...
- Hip dysplasia (human)Hip dysplasia (human)Hip dysplasia, developmental dysplasia of the hip or congenital dysplasia of the hip is a congenital or acquired deformation or misalignment of the hip joint.-Terminology:...
- Acetabular dysplasia (shallow hip socket)
- Frozen shoulder & Loose shoulder
- Traumatized and malaligned joint
- Joint stiffnessJoint stiffnessJoint stiffness may be either the symptom of pain on moving a joint, the symptom of loss of range of motion or the physical sign of reduced range of motion. Doctors prefer the latter two uses but patients often use the first meaning....
Procedural timeline
Before major surgery is performed, a complete pre-anaesthetic work-up is required. In elderly patients this usually would include ECG, urine tests, hematology and blood tests. Cross match of blood is routine also, as a high percentage of patients receive a blood transfusion.Pre-operative planning requires accurate Xrays of the affected joint, implant design selecting and size-matching to the xray images (a process known as templating).
A few days' hospitalization is followed by several weeks of protected function, healing and rehabilitation. This may then be followed by several months of slow improvement in strength and endurance.
Early mobilisation of the patient is thought to be the key to reducing the chances of complications such as venous thromboembolism
Thrombosis
Thrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel is injured, the body uses platelets and fibrin to form a blood clot to prevent blood loss...
and Pneumonia
Pneumonia
Pneumonia is an inflammatory condition of the lung—especially affecting the microscopic air sacs —associated with fever, chest symptoms, and a lack of air space on a chest X-ray. Pneumonia is typically caused by an infection but there are a number of other causes...
. Modern practice is to mobilize patients as soon as possible and ambulate
Walking
Walking is one of the main gaits of locomotion among legged animals, and is typically slower than running and other gaits. Walking is defined by an 'inverted pendulum' gait in which the body vaults over the stiff limb or limbs with each step...
with walking aids when tolerated. Depending on the joint involved and the pre-op status of the patient, the time of hospitalization varies from 1 day to 2 weeks, with the average being 4–7 days in most regions.
Physiotherapy is used extensively to help patients recover function after joint replacement surgery. A graded exercise programme is needed initially, as the patients' muscles take time to heal after the surgery; exercises for range of motion of the joints and ambulation should not be strenuous. Later when the muscles have healed, the aim of exercise expands to include strengthening and recovery of function.
Medical risks
The Stress of the operation may result in medical problems of varying incidence and severity.- Heart AttackMyocardial infarctionMyocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
- Stroke
- Venous ThromboembolismThrombosisThrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel is injured, the body uses platelets and fibrin to form a blood clot to prevent blood loss...
- PneumoniaPneumoniaPneumonia is an inflammatory condition of the lung—especially affecting the microscopic air sacs —associated with fever, chest symptoms, and a lack of air space on a chest X-ray. Pneumonia is typically caused by an infection but there are a number of other causes...
- Increased confusionMental confusionConfusion of a pathological degree usually refers to loss of orientation sometimes accompanied by disordered consciousness and often memory Confusion (from Latin confusĭo, -ōnis, noun of action from confundere "to pour together", also "to confuse") of a pathological degree usually refers to loss...
- Urinary Tract InfectionUrinary tract infectionA urinary tract infection is a bacterial infection that affects any part of the urinary tract. Symptoms include frequent feeling and/or need to urinate, pain during urination, and cloudy urine. The main causal agent is Escherichia coli...
(UTI)
Intra-operative risks
- Mal-positioning of the components
- Shortening;
- Instability/dislocation;
- Loss of range of motionJoint stiffnessJoint stiffness may be either the symptom of pain on moving a joint, the symptom of loss of range of motion or the physical sign of reduced range of motion. Doctors prefer the latter two uses but patients often use the first meaning....
;
- FractureBone fractureA bone fracture is a medical condition in which there is a break in the continuity of the bone...
of the adjacent bone; - Nerve damage;
- Damage to blood vessels.
Medium-term risks
- DislocationDislocationIn materials science, a dislocation is a crystallographic defect, or irregularity, within a crystal structure. The presence of dislocations strongly influences many of the properties of materials...
; - Persistent pain;
- Loss of range of motionJoint stiffnessJoint stiffness may be either the symptom of pain on moving a joint, the symptom of loss of range of motion or the physical sign of reduced range of motion. Doctors prefer the latter two uses but patients often use the first meaning....
; - Weakness;
- Indolent infectionInfectionAn infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
.
Long-term risks
- Loosening of the components: the bond between the bone and the components or the cement may break down or fatigueFatigue (material)'In materials science, fatigue is the progressive and localized structural damage that occurs when a material is subjected to cyclic loading. The nominal maximum stress values are less than the ultimate tensile stress limit, and may be below the yield stress limit of the material.Fatigue occurs...
. As a result the component moves inside the bone, causing pain. Fragments of wear debris may cause an inflammatory reaction with bone absorption which can cause loosening. This phenomenon is known as osteolysisOsteolysisOsteolysis refers to an active resorption of bone matrix by osteoclasts as part of an ongoing disease process.-Osteolysis in joint replacement:...
.
- Polyethylene synovitisPolyethylene synovitisPolyethylene synovitis is an inflammation caused by increased quantities of polyethylene wear particles in the synovial fluid of patients who have had joint replacement surgery....
- Wear of the weight-bearingWeight bearingIn orthopedics, weight-bearing is the amount of weight a patient puts on the leg on which surgery has been performed. In general, it is described as a percentage of the body weight, because each leg of a healthy person carries the full body weight when walking, in an alternating fashion.After...
surfaces: polyethylene is thought to wear in weight-bearingWeight bearingIn orthopedics, weight-bearing is the amount of weight a patient puts on the leg on which surgery has been performed. In general, it is described as a percentage of the body weight, because each leg of a healthy person carries the full body weight when walking, in an alternating fashion.After...
joints such as the hip at a rate of 0.3mm per year. This may be a problem in itself since the bearing surfaces are often less than 10 mm thick and may deform as they get thinner. The wear debris may also cause problems.
There are many controversies. Much of the research effort of the orthopedic-community is directed to studying and improving joint replacement. The main controversies are
- the best or most appropriate bearing surface - metal/polyethylene, metal-metal, ceramic-ceramic;
- cemented vs uncemented fixation of the components;
- Minimally invasiveLaparoscopic surgeryLaparoscopic surgery, also called minimally invasive surgery , bandaid surgery, or keyhole surgery, is a modern surgical technique in which operations in the abdomen are performed through small incisions as opposed to the larger incisions needed in laparotomy.Keyhole surgery makes use of images...
surgery.
Specific joint replacements
- Hip replacementHip replacementHip replacement is a surgical procedure in which the hip joint is replaced by a prosthetic implant. Hip replacement surgery can be performed as a total replacement or a hemi replacement. Such joint replacement orthopaedic surgery generally is conducted to relieve arthritis pain or fix severe...
- Knee replacementKnee replacementKnee replacement, or knee arthroplasty, is a surgical procedure to replace the weight-bearing surfaces of the knee joint to relieve the pain and disability of osteoarthritis. It may be performed for other knee diseases such as rheumatoid arthritis and psoriatic arthritis...
- Shoulder replacementShoulder replacementShoulder replacement is a surgical procedure in which all or part of the glenohumeral joint is replaced by a prosthetic implant. Such joint replacement surgery generally is conducted to relieve arthritis pain or fix severe physical joint damage....
- Ankle replacementAnkle replacementAnkle replacement, or ankle arthroplasty, is a surgical procedure to replace the damaged articular surfaces of the human ankle joint with prosthetic components. This procedure is becoming the treatment of choice for patients, replacing the conventional use of arthrodesis, i.e. fusion of the bones...