Hip Replacement
Glossary of Terms
Alloys: (alcoy)
A substance composed of a mixture of two or more metals. Alloys are used in a
variety of conditions in modern medicine. Implants these days are not made of
one substance but a varied mixture of different substances known as alloys. Such
alloys are used in joint replacement surgeries. Super elastic titanium alloys
and cobalt-based alloys are some of the latest alloys used.
Anatomy: (ana-up, tome-cutting) (a-nat-o-mi)
Anatomy is the study of the structure of an organism and its morphology. This
science describes the structure and orientation of the various parts of an
organism.
Arthoplasty: (artho-joint; plasty-create/mould)
Arthoplasty literally means an operation for construction of a new movable
joint. Usually arthoplasty is done for painful joints where joint movement is
desirable. This operation is done commonly for conditions such as Osteoarthritis
of the hip and knee, Ankylosis of the elbow and un-united femoral neck fracture.
There are three types of arthoplasty
• Excision arthoplasty
• Half joint replacement arthoplasty
• Total replacement arthoplasty (such as total hip replacement)
Arthroscopy: (ar-th-ro-sko-pi) (Greek Arthron-joint; Skopeo- to view)
This is a technique where a thin endoscope, about 4-5mm in diameter is inserted
through an opening created in the joint in order to examine the interior of the
joint.
This technique is now advanced enough to tackle most of the joint problems in
the same setting.
Avascular necrosis: (a-absent; vascular-blood supply; necrosis: death of
a tissue)
Any tissue devoid of nutrition will die; medically this cell death is called as
necrosis. Avascular necrosis is death of bone due to loss of its blood supply.
Bones are also living tissue supplied by blood vessels. When a fracture or a
dislocation disrupts this nutritional supply the bone dies. This usually occurs
in a fracture of the neck of the femur bone; here the head of femur undergoes
necrosis. Adults between ages 20-40 are most susceptible. Other causes may be
steroid therapy, Alcoholism, patients on renal dialysis, anti cancer drugs etc.
but mostly the cause is unknown
Avulsion: (^-v\lcsh\n) Origin[L. a-vello, pp. -vulsus, to tear away]
Avulsion is tearing away or forcible separation. Avulsion injuries are common in
road traffic accidents. These injuries tear away ligaments causing joint
dislocation and internal and external bleeding leading to formation of hematomas.
Ball and socket joint:
This is a type of joint. Joints are classified based on their articulation and
mobility. Ball and socket joints offer the greatest mobility. Such joints are
formed of two or more bones comprising of a ball (usually the head part of one
bone) and a bowl like socket (usually on the opposing surface of the head.)
Examples are the hip joint and the shoulder joint.
Bipolars:
Bipolar devices are artificial joint articulating devices usually resembling the
socket part of a normal ball and socket joint. In such a device, the movement
takes place inside the implant instead of the acetabulum, thus sparing the
acetabular cartilage. Bipolars made of polyethylene and ceramic have gained
popularity over the recent years.
Brace: (br-ace)
Origin[M. E., fr. O. Fr., fr. L. bracchium, arm, fr. G. brachion]
An orthopedic appliance that supports or holds in correct position any movable
part of the body and that allows motion of the part, in contrast to a splint,
which prevents motion of the part. Braces are great devices to set the correct
orientation of joints
Bursitis:
Bursitis is inflammation of the bursa. Bursas (bur’sah) (Latin-purse) are closed
sacs lined with membrane containing fluid. They are found or formed in the areas
of friction. These structures are also prone to infection causing bursitis,
which may also be a cause of chronic joint pain and swelling.
Corticosteroids: (korcti-ko-ster-oid)
A substance produced by the adrenal gland. Artificially produced steroids are
increasingly used in modern medicine because of their excellent pharmacological
properties. Steroids suppress the immune system and are useful in conditions
like rheumatoid arthritis where the immune system turns on the human body
tissues. Steroids also have side effects such as weight gain and other problems
and must not be used in conditions like diabetes, asthma etc.
Cartilage: (kar-ti-lij): from the Latin word Cartilago
Cartilage is a type of dense, tissue like substance that is hard in consistency.
Cartilage is composed of cells called as Chondrocytes. These cells are dispersed
in a gel like matrix. Cartilage is not supplied by blood vessels but is kept
alive by the nutrients diffusing through the matrix. Cartilage is found in
joints, nose, ear, throat, the space between each vertebra and even in the rib
cage. Cartilages have a very good nerve supply which makes any injury to them
very painful.There are three main types of cartilage: hyaline, elastic and
fibrocartilage. Cartilage usually covers the articulating surfaces of the
joints. In the hip they are found covering the head of the femur bone and the
cavity that holds the head in the pelvis.
Ceramic: (from Greek word meaning ‘potter’s clay’)
The challenge today in internal prosthetics is to develop materials that are
stronger and more durable and much tolerable by the human body. The use of
ceramic in hip prosthesis has a lot of research into it. The alternatives to
traditional polyethylene materials used in total hip replacement arthoplasty
include cross-linked polyethylene components and hard-on-hard bearings including
metal-on-metal and alumina-on-alumina ceramic. When comparing hard-on-hard
bearings, the ceramic-on-ceramic coupling has many theoretical advantages.
Ceramic has extremely low coefficient of friction and a high potential for wear
resistance and less debris, this translates into an artificial joint that is
more close to the normal hip.
Crutches: (kr\tch)
A device used singly or in pairs to assist in walking when the act is impaired
by a lower extremity (or trunk) disability; it transfers all or part of weight
bearing to the upper extremity.
Diplegia: (dU-plTcjT-^) Origin [G. di-, two, + plTgT, a stroke]
Diplegia is the loss of function and sensation of corresponding parts on both
sides of the body. Diplegia may occur because of the paralysis of nerves passing
from the spinal column to the corresponding limbs. Diplegia causes wasting of
the muscles of the limb making them degenerate without any excitatory impulses
from the nerves.
Dislocation: (dis-lb-kQcsh\n)
Term used to describe the displacement of an organ or any other part.
Dislocation specifically means a disturbance or disarrangement of the normal
relation of the bones in the formation of a joint. Dislocation weakens the
ligaments and thus the joint may become loose and dislocate repeatedly. Hence it
is necessary to set right a dislocated joint as soon as possible
Degeneration (de-jen-er-a-tion)
Degeneration literally means sinking from a higher level to a lower one.
Medically degeneration is defined as a regressive change in the cells and
tissues of a particular part as a consequence of which the functions may be
inhibited or destroyed. In a fracture of the hip bone for example the affected
individual is unable to use his huge bulk of leg muscles causing them to loose
their function, they slowly degenerate, this is why you need physiotherapy or
rehabilitation techniques to enable you to stop this degeneration. Degeneration
may also occur after an operation to replace the diseased joint, hence it is
absolutely necessary to do the necessary exercises and workouts to prevent
degeneration.
Dysplasia (Dys-bad or difficult; plasia- moulding)
Dysplasia usually refers to an abnormal tissue that is not formal for that organ
or part. Example, the growth of bone in the place of a soft tissue. Dysplasia
may stiffen a joint making movements painful, producing chronic joint pain.
Dysplastic change can be identified only through specific investigations.
Embolism (embolisma - a piece or patch/ something thrust in)
Embolism is the obstruction or occlusion of a vessel by a transported clot, gas,
a mass of bacteria or by any other foreign material.
Epidural: (ep-i-dur-al) anesthesia
Anesthesia is given upon (or outside) the dura mater. There are several
anatomical layers that cover the spinal cord. The space just above the cord and
the cerebral spinal fluid is called the subarachnoid or subdural space. The area
adjacent or above this is the epidural space. Epidural anesthesia is placed in
contact with the dura, but not entering it. Here the anesthetic substance may
move up the spinal cord and affect the respiration.
Hematoma: (he-mat-o-ma) (Greek haimat- blood, oma-tumor)
Hematoma as the name suggests, is not a tumor but a localized collection of
blood out side a blood vessel, contained within an organ or tissue. The blood is
usually in a clotted (solidified) state. The color and consistency of a hematoma
depends on the time after the leakage of blood into that tissue.
Implant: im-plant [L. im-, in, + planto, pp. -atus, to plant, fr. planta,
a sprout, shoot]
The term implant means to graft or insert. A material is inserted or grafted
into tissues. In orthopedics, a metallic or plastic device is employed for joint
reconstruction.
Intathecal anesthesia: (in-tra-te-ick-al)
Anesthesia is given within a sheath, within either the subarachnoid or the
subdural sheath. Instillation of intrathecal medication is a newer technique but
it is performed in much the same way as epidural anesthesia. A very small dose
of an anesthetic is mixed with a local anesthetic and placed within the subdural
sheath. The risks of overdosage and toxicity with local anesthetics are minimal
because of the small dose necessary.
Metabolism: (me-tab-o-lizm) (Greek metabole- change)
Metabolism refers to the sum of chemical changes that take place in a cell. This
consists of Anabolism (a energy consuming, body building process) and Catabolism
(energy giving, breakdown process). In Anabolism small molecules are converted
into bigger ones and in catabolism big molecules are broken down into smaller
ones giving energy.
Hemophilia: (He-mo-fil-i-ah) (Greek haimat-blood, philos-fond)
This inherited disorder of blood is manifested by an increased tendency to
bleed. It causes a defect in the body’s mechanism to control bleeding, even if
it is due to trivial injury. There are two types hemophilia, namely A and B.
Some of the manifestations are:
Bleeding that doesn’t stop within a few minutes of infliction, Hemearthrosis or
bleeding into a joint cavity producing painful hot swollen joints and muscle
hematomas in the calf. .
Idiopathic: (id-io-path-ik) (Greek idios-one’s own; pathos-suffering)
Idiopathic denotes a disease of an unknown cause. For example, most people with
avascular necrosis have no identifiable cause. In them, the disease is
idiopathic.
Inflammation: (in-fla-ma-shun)
This is a fundamental pathologic process. It consists of a dynamic change in the
action of cells in the affected blood vessels and tissues, caused by a physical
chemical biological agent. The main signs of inflammation are redness, pain,
warmth and swelling accompanied with or without loss of function.
Invasive: (in vasus- to go into attack)
The beginning or incursion of a disease is termed as invasive. The term usually
refers to an infectious organism or cancer cells capable of metastasis.
Ligament: (lig- a- ment): (from the Latin word ligamentum meaning
‘bandage’)
A ligament is a band or a sheet of tissue that connects two or more bones or
cartilage. Extra capsular ligaments are the structures that hold the bones of
various joints together. They keep them just apart so as to achieve maximum
mobility with minimum friction. Some ligaments are specifically designed to
restrict movement. Capsular ligaments are part of the capsule surrounding a
joint. Their main function is to reinforce the joint. Ligaments are slightly
elastic under tension. That is why a dislocated joint must be rest quickly to
prevent the ligaments becoming lax and causing future problems.
Manoeuvre: (ma- nu-ver) (Fr. Mnoeuvee- to work by hand)
A planned movement or procedure designed to achieve a specific purpose.
Marrow: (mar’o)
Bones are not completely solid. Some bones like the long bones of the arms and
the legs have cavities in them to make them light. This cavity is filled with a
soft fatty substance called the marrow. These sites, being highly nutritious,
are a favorite site for infection by pyogenic organisms. They destroy the joint,
causing fever and joint pain.
Osteoarthritis: (osteo-bone; arthron- joint; it is a suffix for
inflammation)
Osteoarthritis is a type of arthritis that is caused by the breakdown and
eventual loss of the cartilage of one or more joints. Osteoarthritis commonly
affects the hands, feet, spine, and large weight-bearing joints, such as the
hips and knees. Most cases of osteoarthritis have no known cause and are
referred to as primary osteoarthritis. When the cause of the osteoarthritis is
known, the condition is referred to as secondary osteoarthritis.
Polyethylene:
Polyethylene is a polymer of ethylene that is resistant to chemicals and
moisture and has good insulating properties. It is used in making artificial
joint surfaces (bipolars) to increase their durability.
Prosthesis: (pros’the-sis) derived from a Greek word meaning addition
Prosthesis is a fabricated substitute for a missing part of the body. A
Prosthetic can be used to replace a body part externally (artificial limb) or
internally (artificial hip joint). Prosthetic can be cosmetic or functional. If
they do not have sensation or any power they are called as body powered
prosthesis. Some prosthesis are externally powered to be more versatile and more
functional than cosmetic. Improved materials, new designs and better evaluation
and fitting techniques have resulted in prosthesis that is lighter and stronger
Pyogenic: (pi-yo-jen-ik) (Greek pyon-pus; genesis-producing)
Any agent that causes pus producing is potentially pyogenic. Usually the
organism is a bacterium. It reaches the bone or any other tissue via blood and
lodges itself in the tissue thereby destroying the structures. The immune system
combats the infection, resulting in the death of a large number of cells. These
cells are collected as pus. The bones of the hip and knee joint are commonly
involved.
Physiotherapy: (physio- nature; therapy- treatment) (fiz-I-o-ther-a-pi)
Physiotherapy involves the use of natural force in the treatment of disease. It
involves the use of certain procedures that help achieve the natural physiologic
function of that particular muscle or joint.
Reamer: (re’mer) (A.S to widen):
A reamer is a rotating instrument with spirally turning blades used for
enlarging a cavity. It is used for root canal treatment; and a slightly larger
version is used for making the bone cavity larger to fit an internal prosthesis
in joint replacement surgeries.
Rehabilitation: (from a Latin word meaning ‘to restore a former rank’)
Rehabilitation is the concentrated efforts designed to guide a person with a
major disability enabling them to lead a useful life within their constraints of
their disability. Rehabilitation may be physical, social or economic. Physical
rehabilitation consists of making the individual as independent in his
activities of daily living as possible. This includes the use of wheel chairs or
other supporting devices that help a person to be mobile. It also includes good
physiotherapy and occupational therapy to restore the function of the affected
part. Social rehabilitation involves in keeping the morale of the affected
individual high. Relatives, friends and social organizations have a great role
to play in this. Economic rehabilitation involves equipping the individual with
skills to do a worthwhile job outside his disability.
Rheumatoid arthritis:
Arthritis is inflammation of a joint. Rheumatoid arthritis is a special form of
arthritis, which is caused because of a disorganized immune system. Some people
are genetically prone to this disease, such persons when exposed to a particular
infection develop antibodies, which cross-react with the joint tissues causing
chronic pain and swelling. Rheumatoid arthritis is characterized by morning
stiffness, swelling in three or more specified joints (shoulder or elbow or
wrist or the hip or the knee), Symmetrical swellings, a nodule in the hands or
legs etc. If you have any of these symptoms you should consult your family
doctor.
Sickle Cell Anemia:
Anemia is a qualitative or quantitative reduction in the RBC (red blood cells)
of blood. Sickle cell anemia, which is a genetically acquired disease, is a
qualitative reduction in the RBC function. It is characterized by the presence
of sickle or crescent shaped cells in the blood.. A Pale tongue and eyes,
fatigability, lack of usual energy, leg ulcers and arthrotic problems are the
main manifestations of this disease.
Spurs:
A spur is a small projection from any structure. A bony spur is a spine or a
projection from a bone. ‘Spur’ is an archaic term for a horny outgrowth from the
skin. Spurs may press upon the arteries or affect the attachment of muscles to
joints causing unexplained pain. Spurs are easily diagnosable through X-rays.
Tendon: (from Latin tendere meaning “to stretch”)
Tendon is a fibrous chord or band that connects a muscle to a bone or other
structures. Tendons are strong because they contain very little cells but a lot
of a substance called as collagen. They are also not that stretchable like a
muscle, which makes them vulnerable to stretch injury. There are many tendons
around the hip joint because of the huge group of thigh and pelvic muscles. Even
injury to one of the tendons may cause instability of the hip joint.
Thrombophlebitis: (throm-bo-fle-bi-tis)
Origin [thrombo- + G. phleps, vein, + -itis, inflammation]
Thrombophlebitis is venous inflammation with blood clot formation. This causes
severe pain and sweling because the blood cannot drain away properly from the
tissues. Also, other channels of drainage become prominent, thereby causing
superficial veins to be seen beneath the skin giving an ugly appearance. Usually
these veins are not visible.
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