Glossary of Terms

“How do I understand my own medical records and what my doctors are telling me?”

Medical terminology can be exceedingly complex and confusing.  To most people it’s a foreign language.  We see our clients understandably struggle to learn this language every day, so we thought to do something about that.

While this is not a fully comprehensive list, here are over 200 medical terms and specialties associated with traumatic brain injury often found in medical literature and patient medical records.  We hope you find this helpful.  Should you have any questions about the content in this Traumatic Brain Injury Glossary, we encourage you to reach out to us.


ACL Tear:
Knee injuries, much like ankle injuries, occur in activities involving quick turns, abrupt stops and starts, or unpredictable motions. This is commonly seen in sports including golf, basketball, soccer and skiing. Hearing a pop or experiencing a sharp pain in your knee after taking a hard turn may mean that the ACL was injured. An ACL tear makes it difficult to bend the knee, and people often suffer a feeling of instability when standing.

Anterior lumbar interbody fusion. An operation for stabilization of the spine using an anterior approach. This is the standard approach for inserting cages in the lumbar disc spaces.

Ankle Sprain:
A sprained ankle is an injury that is common within activities or sports which involve a high level of jumping, pivoting and running. If a rolled ankle has sent you to the sidelines, visit the foot and ankle injury experts at OrthoNOW® right away for treatment.

Ankylosing Spondylitis:
An inflammatory disease that, over time, can cause some of the vertebrae in the spine to fuse. This fusing makes the spine less flexible and can result in a hunched forward posture. If ribs are affected, it can be difficult to breathe deeply. It affects men more than women.

Annulus Fibrosis:
The tough circular exterior of the intervertebral disc. that surrounds the soft inner core (nucleus pulposus) and is designed to contain and protect it.

The front portion of the body. It is often used to indicate the position of one structure relative to another.

Anterior Cruciate Ligament (ACL):
The ligament, located in the center of the knee, that controls rotation and forward movement of the tibia (shin bone).

Situated or occurring in front of and to the side.

Antiglide Plate:
A hardware construct that uses weight bearing to provide dynamic compression of a fracture. It is usually employed for oblique fractures of the fibula. A plate with screws is affixed to the proximal fibula such that the tip of the distal fracture fragment is wedged between the plate and the proximal fragment. It is not necessary to place screws in the plate distal to the fracture, although an “anti-glide” screw can be placed at the apex of the fracture.

Arbeitsgemeinschaft fur Osteosynthesfragen/Association for the Study of Internal Fixation. An association founded in Germany to study and promote the use of internal fracture fixation. The association has an education program for teaching surgical methods. There are national branches of the association in several countries. In the United States, it is the Association for the Study of Internal Fixation. Several types of orthopedic hardware have been developed by AO, and they are given AO designations, e.g. an AO screw.

Inflammation of a joint, usually accompanied by pain, swelling, and sometimes change in structure.

The fusion of bones across a joint space, thereby limiting or eliminating movement. It may occur spontaneously or as a result of a surgical procedure, such as fusion of the spine.

Arthrography is often used to help diagnose the cause of unexplained joint pain. A contrast iodine solution is injected into the joint area to help highlight the joint structures, such as the ligaments, cartilage, tendons and joint capsule. Several X-rays of the joint are taken, using a fluoroscope, a special piece of X-ray equipment that immediately shows the image. You may be asked to fast prior to the exam. During the examination, you may be asked to move the joint into various positions as the images are taken. It is normal to experience some discomfort or tingling during the procedure. If you are or may be pregnant, or are allergic to iodine or shellfish, notify your physician; you may be at a higher risk of complications.

Joint disease. A degenerative disease that affects the joints of the spine and the break down of cartilage on those joints.

An operation that restore as far as possible the integrity and function of a joint. In general, an arthroplasty involves prosthetic replacement of one or both sides of a joint. A hemiarthroplasty involves replacement of only one side of a joint. A total joint arthroplasty involves replacement of both sides of a joint. A hemiarthroplasty may be unipolar of bipolar.

An instrument inserted into a joint cavity to view the interior of a joint and correct certain abnormalities. An arthroscope is an endoscope for use in a joint.

A minimally-invasive diagnostic and treatment procedure used for conditions of a joint. This procedure uses a small, lighted optic tube (arthroscope) which is inserted into the joint through a small incision in the joint. Images of the inside of the joint are projected onto a screen; used to evaluate any degenerative and/or arthritic changes in the joint; to detect bone diseases and tumors; to determine the cause of bone pain and inflammation.

Pertaining to movement of a joint.

Austin-Moore Prosthesis:
A metallic unipolar femoral prosthesis used in hip hemiarthroplasties. It was one of the earliest prosthetic devices. Femoral prostheses are sometimes referred to as Moore or Austin-Moore prostheses.

Autogenous Bone:
Bone originating from the same individual; ie, an individual’s own bone.

Autograft Bone:
Bone transplanted from one part to another part of the body in the same individual.


Bipolar Prosthesis:
A two component prosthesis used for hemiarthroplasties in which one prosthetic component is fixed rigidly in place on one side of the joint and the second component with which the first articulates is inserted loosely on the other side of the joint. The prosthesis is named after the fixed component. Motion of the across the joint component puts less stress on bone and the articulating surfaces. As an example, one design of a femoral bipolar hemiarthroplasty consists of a prosthetic femoral head articulating with a polyethylene liner in the acetabular component. The liner is inside a metal shell and can move with respect to the shell. The shell is press fitted into the acetabulum either with or without reaming of the acetabulum. The shell can move within the acetabulum. It is important when reading x-rays of bipolar implants to be aware that the across the joint component is mobile and not to interpret a change in position of this component as necessarily indicative of loosening. See unipolar prosthesis.

Bone Graft:
Bone which is harvested from one location in an individual and placed in another individual (allograft bone) or in a different location in the same individual (autogenous bone).

Bone Marrow:
The tissue contained within the internal cavities of the bones. A major function of this tissue is to produce red blood cells.

Bone Morphogenetic Proteins:
Bone morphogenetic proteins, BMPs, are a group of endogenous proteins that stimulate bone growth. Recombinant human bone morphogenetic protein two, rhBMP-2, is the only FDA approved BMP for human use. It is used with bone grafts and spinal cages for interbody fusion of vertebral bodies.

Bone Plate:
Usually a relatively thin metal device which is affixed to bone via screws. Bone plates are used to immobilize bones or bone fragments such that healing can occur.

Bone Scan:
Two very different kinds of tests may be called bone scans. One type tests the density of the bone and is used to diagnose osteoporosis. This type of bone scan uses narrow X-ray beams or ultrasound to see how solid the bone is. No preparation is required for this test, which takes only a few minutes and has no side effects. (See Dual-Photon Absorptiometry, Dual-Energy X-ray Absorptiometry, and Peripheral Bone Density Testing.)
The second type of bone scan is used to identify areas where there is unusually active bone formation. It is frequently used to pinpoint stress fracture sites or the presence of arthritis, infection, or cancer. About three hours before the scan, you will be given a dose of a mildly radioactive substance called “technetium” through an intravenous line (IV). This substance occurs naturally in your body and is used in the bone formation process. The bone scan itself is performed about three hours later, which gives the bone time to absorb the technetium. As you lie on a table, a special nuclear camera takes a picture of your entire body. This process takes 30 to 90 minutes. Areas of abnormal bone formation activity will appear brighter than the rest of the skeleton.
No fasting or other preparation is required. The amount of radioactivity absorbed during a technetium bone scan is minimal, and there are usually no side effects. You may feel some discomfort as the IV line is placed. Some people may feel nauseous. Tell your physician if you are or may be pregnant or are a nursing mother before you schedule this test.

Bone Screw:
A threaded metal device which is inserted into bone. The functions of bone screws are to immobilize bones or bone fragments or to affix other medical devices, such as metal bone plates, to bones.

A sac filled with fluid between a bone and a tendon or muscle often attacks small joint, especially the big toe. It can usually be controlled with medication and changes in diet.


Cancellous Bone:
The spongy or honeycomb structure of some bone tissue typically found at the ends of long bones.

Cancellous Screw:
A screw designed for placement in cancellous bone. The pullout strength of a screw is proportional to the amount of metal-bone contact. Because cancellous bone is porous, threads for cancellous bone screws have to be longer than for cortical screws to achieve the same degree of metal-bone contact and thus have the same pullout strength as cortical screws.

Carpal Tunnel Syndrome:
This is caused by a pinched nerve in the wrist. Things that can lead to carpal tunnel syndrome include: hypothyroidism, diabetes, rheumatoid arthritis, pregnancy, obesity, wrist injuries, bone spurs, and smoking because it can reduce blood flow to the medial nerve. Patients should see an orthopedic specialist if they are experiencing tingling, weakness, or pain in the fingers or hand that keeps coming back or that has not gone away after two weeks of home treatment. A common misconception is that typing or texting causes carpal tunnel syndrome. Although these can certainly aggravate the symptoms, typing or texting alone can’t cause carpal tunnel syndrome.

The hard, thin layer of white glossy tissue that covers the end of bone at a joint. This tissue allows motion to take place with a minimum amount of friction.

The body of a vertebra.

The neck region of the spine containing the first seven vertebrae.

The region of the spine below the sacrum. It is also known as the tailbone.

A fibrous protein which is a major constituent of connective tissue, such as skin, tendons, ligaments, cartilage, and bones.

Comminuted Fracture:
A fracture in which a bone is broken into more than two pieces. Often internal or external fixation devices are used to maintain proper alignment of the fragments.

Compensatory Curve:
A curve, which can be structural, above or below a major curve that tends to maintain normal body alignment. This type of curve may develop in cases of scoliosis in children and adults.

The act of pressing together – refers to the loss of vertebral body height either anteriorly, posteriorly or both.

Computed Tomography (CT Scan):
A CT scan (computed tomography) combines X-rays with computer technology to produce a more detailed, cross-sectional image of your body. It may be ordered if your doctor suspects a tumor or a fracture that doesn’t appear on X-rays (such as in your collarbone or pelvis) or if you’ve had severe trauma to the chest, abdomen, pelvis or spinal cord. The process is painless. You lie motionless on a table as it slides into the center of the cylinder-like CT scanner. An X-ray tube slowly rotates around you, taking many pictures from all directions. A computer combines the images to produce a clear, two-dimensional view on a television screen. You may need to drink or be injected with barium sulfate or a dye so that certain parts of your body can be seen more clearly. The drink has a chalky taste and may make you feel nauseous; a dye injection may be moderately painful. Tell your doctor if you are pregnant before undergoing a CT scan.

Present at and existing from the time of birth.

Cortical Bone:
Bone tissue which has been depleted of its minerals; e.g. calcium and phosphorous.

Cortical Screw:
A screw designed for placement in cortical bone. See cancellous screw.


Disc (Intervertebral):
The tough, elastic structure that is between the bodies of spinal vertebrae. The disc consists of an outer annulus fibrosus enclosing an inner nucleus pulposus.

Disc Degeneration:
The loss of the structural and functional integrity of the disc. This disorder is often called Degenerative Disc Disease.

The surgical removal of abnormal disc material that presses on a nerve root or the spinal canal causing pain, weakness or numbness.

Discography is a test used to determine whether the discs, the cushioning pads that separate the bones of the spine, are the source of back pain. It may be performed before surgery to positively identify the painful disc(s).
Before the procedure begins, you will be given antibiotics and relaxation medications through an IV line. Medication is used to numb the skin over the test site. During the procedure, the doctor inserts a needle into one or more discs and injects a contrast dye. You’ll feel pain when the dye is introduced into the problem disc. Afterward, a CT scan will show any changes in the disc size or shape. You may experience some muscle discomfort after the procedure; your doctor can prescribe pain relievers to ease the discomfort.
No special preparations are required for this test. However, you should not take any pain relievers or anti-inflammatory medications on the day of the procedure.

A dislocation occurs when extreme force is put on a ligament causing the two bone ends to separate. Dislocations can also affect a joint, the point where two or more bones come together. The joint is created as a “ball-and-socket” joint. A dislocated joint causes the head of the bone (ball) to partially or completely come out of the socket.

Situated away from the center of the body.

Distal Radius Fracture:
Commonly known as wrist fractures, these occur when you fall on an outstretched hand. In some cases, a cast may be all that is necessary to treat these injuries, but these fractures tend to be unstable and usually require surgical treatment.

Space between fracture fragments or vertebral segments due to interposed tissue or, most often, axial forces. Distraction may also be part of a surgical procedure wherein spinal structures are separated, lengthened or shortened.

Doppler Ultrasound:
An orthopaedist who suspects that you have a blockage in the blood vessels of your legs or arms may prescribe an ultrasound test. An ultrasound uses high-frequency sound waves that echo off the body. This creates a picture of the blood vessels. The Doppler audio system transmits the “swishing” sound of the blood flow. This is a noninvasive test that has no side effects.
A clear jelly is applied to the skin over the blood vessels being tested. The technician uses a sensor that looks like a microphone. The sensor is placed against the skin and moved up and down across the area being tested. The technician will apply pressure every few inches to see if the blood vessels change their shape. The test takes about 30 minutes, and most people experience no pain or discomfort.

Dual-Photon Absorptiometry:
Dual-photon absorptiometry (DPA}, a test for osteoporosis, has been mostly replaced by dual-energy X-ray absorptiometry (DEXA). DPA measures bone density in the spine, hip, or total body using a photon beam. Although accurate for predicting fracture risk, precision is poor.

Dynamic Compression:
The compression of a fracture by weight bearing and/or muscle contraction. Fracture fixations that employ dynamic compression include dynamic hip screws, anti-glide plates, dynamized tibial and femoral nails, and tension band wiring.


An electromyography (EMG) records and analyzes the electrical activity in your muscles. It is used to learn more about the functioning of nerves in the arms and legs. For example, a fracture of the upper arm bone (humerus) may tear or pinch the radial nerve. An EMG can be used to identify the damage if nerve function doesn’t return within 4 months of the injury.

Ender Nail:
Also referred to as an Ender rod. A smooth, flexible rod used for intramedullary fixation of long bone fractures. The nail is used for diaphyseal fractures in patients whose epiphyseal growth plates are still open. It is inserted through the metadiaphyseal region, avoiding the epiphyseal plate so that the growth of the bone is not impaired.

Arising within or derived from the body.

A medical instrument for viewing internal portions of the body. An endoscope is a tubular device and camera to enable visualization of the patient’s anatomy on a monitor.

Inspection of internal body structures or cavities using an endoscope.

Situated outside the thin, tough dural membrane that surrounds the brain and spinal cord. An epidural is also a type of diagnostic and therapeutic spinal injection.

Epidural Spinal Injection (ESI):
An injection of a local anesthetic (numbing medication) and steroid medication into the epidural space of the spine to reduce inflammation due to narrowing of the passages where the nerves travel as they pass down and out of the spine.

Removal by cutting away material.

Originating outside of the body.


Facet Joint:
Facet joints are the joints in your spine that make your back flexible and enable you to bend and twist. Nerves exit your spinal cord through these joints on their way to other parts of your body.

Excision (removal) of a facet.

Fatigue Fracture:
A fracture that occurs in bone or in other materials, including metal, as a result of repeated stress as opposed to a single injury.

The replacement of normal tissue with scar tissue.

To hold in place. Orthopedic hardware can be used to fixate bone, for example with fracture repairs. Bone can be used to fixate orthopedic hardware as with joint prostheses.

Flexibility Tests:
Flexibility tests are used to measure the range of motion in a joint and are often part of the physical examination. They may be used to help determine whether you have a muscle imbalance or arthritis in a joint. They may also be used to help determine the progression of a condition such as shoulder impingement or a sprain. There are several different kinds of flexibility tests, geared to specific joints and muscles. Your doctor may ask you to reach or bend or to move the affected extremity in a certain way. No preparation is required, and normally these tests are not painful.

Food and Drug Administration:
All implantable orthopedic hardware in the United States must be approved by the Food and Drug Administration (FDA). The FDA classification of hardware is specified in the code of federal regulations (CFR) under Title 21, part 888, Orthopedic Devices. Devices are classified by type and anatomic region. For joint replacements, the main classification areas are the degree of constraint, composition, cemented or noncemented., and a few subcategories. The classification can be found by searching the Center for Devices and
Radiological Health Database at

A natural opening or passage in bone. Neuroforamen are nerve passageways created between two vertebral bodies.

Foraminal Stenosis:
The narrowing of the intervertebral foramen, a small hole through which nerves exist our spinal canal and travel through the body.

A break in a bone.

Union or healing of bone.


Ganglion Cysts:
Non-cancerous, fluid-filled cysts are common masses or lumps in the hand and usually found on the back of the wrist.

Gerdy’s Tubercle:
A bony projection on the anterolateral tibia plateau between the patellar tendon and fibular head that is used as a landmark for examining or operating on the knee.

A result of a defect in body chemistry (such as uric acid in the joint fluid), this painful condition most often attacks small joint, especially the big toe. It can usually be controlled with medication and changes in diet.


A generic term that encompasses all metallic implants. By extension, it also includes nonmetallic materials associated with metallic components such as polyethylene components of joint prostheses. See implants.

Harrington Rod:
A stainless steel rod surgically implanted along the spinal column to treat, among other conditions, a lateral or coronal-plane curvature of the spine, or scoliosis.

Heel Spur:
A bone growth on the heel bone.

Replacement of one side of a joint with a prosthesis. The prosthesis in a hemiarthroplasty can have a unipolar or bipolar design. In a unipolar design, the prosthetic component is on only on side of the joint. In a bipolar design, there is a prosthetic component on the other side of the joint that is not fixed in place. In a total hip arthroplasty, the across the joint component is rigidly fixed in place. See bipolar hemiarthroplasty.

Herniated Disc:
Is a condition in which the annulus fibrosis (outer portion) of the vertebral disc is torn, enabling the nucleus (inner portion) to herniate or extrude through the fibers which most often compresses on the nerve(s) existing the spinal column.

The bone of the upper arm.


Occurring without known cause. Self–originated.

Iliac Bone:
A part of the pelvic bone that is above the hip joint and from which autogenous bone grafts are frequently obtained.

Iliac Crest:
The large, prominent portion of the pelvic bone at the belt line of the body.

Limitation of motion or fixation of a body part usually to promote healing.

Any surgically placed, non-biological material whose purpose is to promote healing of tissues or serve as a replacement of structures such as joints.

Situated below or directed downward.

A normal reaction to injury or disease, which results in swelling, pain, and stiffness.

Internal Fixation:
The immobilization of bone fragments or joints with implants in order to promote healing or fusion. Internal fixation utilizes spinal instrumentation.


The commonly used designation for Kirschner wires. These are thin wires that used for a variety of purposes. They can act as fixation devices for small bones, as guide wires for insertion of cannulated nails, and as accessory components with external fixation devices.

An abnormal increase in the normal kyphotic curvature usually affecting the thoracic spine.



Sensory awareness of body parts as they move.


Laboratory Studies:
Laboratory studies of blood, urine or joint (synovial) fluids are used to identify the presence and amount of chemicals, proteins, and other substances. Your doctor may order various laboratory studies depending on what he or she finds during the initial examination. For example, laboratory studies can identify the amount of uric acid in the blood, which is an indicator of gout. A high white blood cell count in joint fluid may indicate severe inflammation or infection. Laboratory tests are usually required before surgeries to identify medical abnormalities.
You may be required to fast for a specific number of hours before donating samples for a laboratory test.

Lag Screw:
A screw inserted across a fracture that provides compression to the fracture. Lag screws can provide static or dynamic compression. The term “lag” refers to the function of a screw. The physical design of the screw, the type of bone the screw is inserted into, and the manner in which it is inserted determine whether a screw functions as a lag screw. In the diaphyses of long bones, cortical screws are used as lag screws while cancellous screws function as lag screws for cancellous bone fractures.

An anatomical portion of a vertebra. For each vertebra, two lamina connect the pedicles to the spinous process as part of the neural arch.

A surgical operation to remove the portion of the vertebral bone called the lamina, which is over the spinal canal. Also known as a decompression surgery, it enlarges your spinal canal to relieve pressure on the spinal cord or nerves.

Situated away from the midline of the body.

Lateral Collateral Ligament (LCL):
The ligament that gives stability to the outer knee.

Lateral Epicondylitis (also known as tennis elbow):
Pain caused by damage to the tendons that bend the wrist backward away from the palm.

A white, shiny, flexible band of fibrous tissue that binds joints together and connects various bones and cartilage.

An abnormal increase in the normal lordotic curvature of the lumbar spine.

A non–medical term signifying pain in the lumbar region.

The lower part of the spine between the thoracic region and the sacrum. The lumbar spine consists of five vertebrae.


Magnetic Resonance Imaging (MRI):
An MRI (magnetic resonance image) uses magnetic fields and a sophisticated computer to take high-resolution pictures of your bones and soft tissues, resulting in a cross-sectional image of your body. It can be used to help diagnose torn muscles, ligaments and cartilage, herniated disks, hip or pelvic problems and other conditions. As with a CT scan, you lie on a table that slides into the tube-shaped MRI scanner. The MRI creates a magnetic field around you, then pulses radio waves to the area of your body to be pictured. The radio waves cause your tissues to resonate. A computer records the rate at which your body’s various parts (tendons, ligaments, nerves) give off these vibrations, and translates the data into a detailed, two-dimensional picture. You won’t feel any pain while undergoing an MRI, but the machine may be noisy. An MRI takes 30 to 90 minutes, and is not available at all hospitals. Tell your doctor if you have implants, metal clips or other metal objects in your body before you undergo an MRI scan.

Situated closer to the midline of the body.

Medial Collateral Ligament (MCL):
The ligament that gives stability to the inner knee.

Two crescent-shaped discs of connective tissue between the bones of the knees that act as shock absorbers to cushion the lower part of the leg form the weight of the rest of the body.

Meniscus Tear:
This is a very common knee injury among professional athletes and the elderly. The meniscus helps the knee joint carry weight, glide and turn. This is usually caused by twisting or turning too quickly when the foot is planted and the knee is bent. This injury often causes the knee to be in pain, lock, click and swell. Meniscus injuries are not limited to professional athlete injuries, but rather can also be age limiting where tears can appear in elderly.

Minimally Invasive Surgery:
Surgery requiring small incision(s), usually performed with endoscopic visualization.

Composed of interchangeable parts. With respect to prostheses, femoral hip prostheses are most commonly modular in design. Different types of femoral implants have interchangeable heads, necks, and/or stems. See monoblock.

A single structure without interchangeable parts. See modular.

Muscle Tests:
Because muscles are soft tissues, they do not appear on X-rays. So muscle testing is an important part of the physical examination. Weakness in a muscle may indicate injury to the tendons that connect the muscle to bone, injury to the nerves that enervate the muscle, or a generalized weakness of the muscle itself from disuse.
To test the strength of your muscles, your physician may ask you to move in certain ways while he or she applies a resistive force. For example, your physician may ask you to sit in a chair and then attempt to raise one knee as the doctor presses down on your upper leg. Or, your physician may hold your elbow at a 90-degree angle and ask you to bend your wrist down. Measuring grip strength by asking you to squeeze the doctor’s hand is another type of muscle test.

Involves the injection of a dye or contrast material into the spinal canal, a specific x-ray study that also allows careful evaluation of the spinal canal and nerve roots.

A neurological condition referring to a softening of the spinal cord as a result of hemorrhagic infarction (the bleeding of the spinal cord).


Nerve Conduction Study (NCS):
Nerve conduction studies are often done along with an electromyogram to determine if a nerve is functioning normally. It may be recommended if you have symptoms of carpal tunnel syndrome or ulnar nerve entrapment. The doctor conducting the test will tape wires (electrodes) to the skin in various places along the nerve pathway. Then the doctor stimulates the nerve with an electric current. As the current travels down the nerve pathway, the electrodes placed along the way capture the signal and measure its speed. In healthy nerves, electrical signals can travel at speeds of up to 120 miles per hour. If the nerve is damaged, however, the signal will be slower and weaker. By stimulating the nerve at various places, the doctor can determine the specific site of the injury. Nerve conduction studies also may be used during treatment to test the progress being made. Although you may initially be startled by the suddenness of the stimulation, it is not usually painful and most people are comfortable during the testing procedure. The shock is similar to one received when you touch a doorknob after walking across carpeting.

The surgical treatment of disorders of the brain, spinal cord, and peripheral nerves.

Nerve Root:
The bony arch of the posterior aspect of a vertebra that surrounds the spinal cord, also referred to as the vertebral arch.

Nonself-Tapping Screw:
A screw that requires a tapping procedure in a predrilled guide hole before the screw can be inserted. See self-tapping screw, tap.

Nucleus Pulposus:
The inner core of the vertebral disc. It is composed of a jelly-like material that consists of mainly water, as well as a loose network of collagen fibers.The elastic inner structure allows the vertebral disc to withstand forces of compression and torsion.


Orthopedic Surgeon (also called an orthopedist):
A physician who diagnoses, treats, manages the rehabilitation process, and provides prevention protocols for patients who suffer from injury or disease in any of the components of the musculoskeletal system.

Orthopaedics (also Orthopedics):
The medical specialty involved in the preservation and restoration of function of the musculoskeletal system that includes treatment of spinal disorders and peripheral nerve lesions.

The process of forming bone in the body.

A type of arthritis occurring most often in older patients characterized by chronic deterioration of the cartilage of the joints. Symptoms can include joint pain, stiffness, and swelling.

Refers to any structure that facilitates the formation of bone structure. Commonly used to describe the properties of various types of bone grafts and bone graft substitutes.

Any substance that stimulates bone formation. Bone morphogenetic proteins are osteoinductive.

A smooth bony growth or deposit, also referred to as a bone spur, that slowly grows over time and often has no symptoms. They can cause pain if they impinge on other structures or grow so large to restrict movement in a joint.

A disease in which bone mass and density decreases over time resulting in a weakening of the bones that makes them especially subject to fracture and deformities. This disease most commonly affects older women.


The study of disease states.


The part of each side of the neural arch of a vertebra. It connects the lamina with the vertebral body.

A fibrous membrane that covers the surface of bone except at the end of the bones where it is covered with cartilage as part of a joint. In children, periosteum is involved in forming new bone and molding the configuration of bone; and in the adult, the periosteum forms new bone secondary to injury or infection.

Physical Therapy:
The treatment consists of passive modalities administered to the patient by the practitioner (eg, massage, heat, cold, ultrasound) and active therapies (eg, stretching, exercise). Physical therapy can help a patient gain strength, endurance, range of motion, relearn movements and/or rehabilitate the musculoskeletal system to improve function.

The science of the functioning of living organisms, and of their component systems or parts.

The distance between threads on a screw. Cancellous bone screws have a larger pitch than cortical bone screws.

Plantar Fasciitis:
Plantar fasciitis is the most common cause of heel pain. It is caused by repeated strain on the plantar fascia, the ligament that connects the heel bone to the toes, supporting the arch of the foot. A strained plantar fascia causes weakness, swelling, and inflammation in one or both heels.

Located behind a structure, such as relating to the back side of the human body.

Posterior Cruciate Ligament (PCL):
The ligament, located in the center of the knee, that controls backward movement of the tibia (shin bone).

Press Fit:
A method for implanting orthopedic devices. For a press fit, a device is inserted without cement or hardware fixation. The geometry of adjacent structures holds the device in place. The acetabular component of a bipolar femoral prosthesis is press fitted into the acetabulum. The stem of uncemented femoral prostheses are press fitted into the medullary canal of the proximal femur. Also referred to as interference fit.

An artificial body part such as an artificial leg or arm. The term prosthesis is also used to describe some of the implants used in the body such as a hip or knee replacement device.

Nearest the center of the body.

Pseudoarthrosis (also Pseudarthrosis, failed fusion):
A form of a non–union in which there is the formation of a false joint with some cartilage covering the ends of the bones and a cavity containing fluid that resembles a normal joint. The term also applies to failed fusion, which occurs when two or more bones do not heal (join) together following a spinal surgery wherein fusion is performed.


Quantitative Computed Tomography:
Quantitative computed tomography {QCT) is used to measure bone mineral density (BMD) for osteoporosis. It is similar to a normal CT scan, but uses a computer software package that determines bone density in the hip or spine. This technique provides for true three dimensional imaging and reports BMD as true volume density measurements. This enables the physician to focus on a particular area. QCT uses a higher dose of radiation than the standard test for osteoporosis, the dual-energy X-ray absorptiometry test, and may also be more expensive. (See Computed Tomography, Dual-Energy X-ray Absorptiometry.)


Radiographs (X-rays):
X-rays (radiographs) are the most common and widely available diagnostic imaging technique. Even if you just complain about a sprain in your wrist or ankle, your doctor will probably order radiographs to make sure no bone is broken. X-rays are always used for fractures and joint dislocations, and may also be recommended if your doctor suspects damage to a bone or joint from other conditions such as arthritis or osteonecrosis (bone cell death). The part of your body being pictured is positioned between the X-ray machine and photographic film. As you hold still, the machine briefly sends electromagnetic waves (radiation) through your body. This exposes the film, creating a picture of your internal structure. The level of radiation exposure from X-rays is minimal, but your doctor will take special precautions if you are pregnant. Bones, tumors and other dense matter appear white or light because they absorb the radiation. Soft tissues and breaks in bone let radiation pass through, making these parts look darker. Sometimes, to make certain organs stand out in the picture, you are asked to drink barium sulfate or be injected with a dye. Several X-rays from different angles may be needed. If you have a fracture in one limb, your doctor may want a comparison X-ray of your uninjured limb. Your X-ray session will probably take 10 to 15 minutes; no specific preparations are required.

The shorter of the two bones of the forearm.

Range of Motion Testing:
Range of motion tests may also be called flexibility tests. They are used to measure how well you can move a joint. Some joints like the thumb and shoulder have a wide range of motion, almost a complete circle. Other joints like the knee are like hinges and have a more limited range of motion. Range of motion tests may be active or passive. In active tests, you do all the movement. In passive tests, the doctor will hold the extremity and move it. He or she may also hold the next joint steady to isolate the movement of the joint being tested. For example, while you are seated, the doctor may hold your lower leg still while moving your heel in and out. (See Flexibility Tests.)

The process of enlarging a cavity so that a prosthesis can be inserted. Reaming most commonly is performed in the femur for insertion of a femoral nail.

Reconstruction Nail:
A femoral intramedullary nail used to fixate femoral neck, intertrochanteric, and subtrochanteric fractures. There is a proximal hold for an interlocking femoral screw that is placed in the femoral neck or head.

The surgical removal of part of a structure, such as bone.

The removal of bone tissue by normal physiological process or as part of a pathological process such as an infection. Bone resorption also is part of the normal bone remodeling process wherein new bone is formed.

A posterior displacement of one vertebral body with respect to the subjacent vertebra to a degree less than a dislocation (form of spondylolisthesis).

Rheumatoid Arthritis:
An inflammatory disease that involves the lining of the joint (synovium). The inflammation often affects the joints of the hands and the feet and tends to occur equally on both sides of the body.

A physician who specializes in the treatment of arthritis and other rheumatic diseases that may affect joints, muscles, bone, skin and other tissues.

Surgical transection of a nerve root.

The movement of one vertebra to another about its normal or abnormal coronal axis.

Rotator Cuff Tear:
This may be caused by an injury to the shoulder, or due to progressive degeneration or wear & tear of the tendon. Symptoms include pain and extreme stiffness when raising your arm above your head or when moving your shoulder. Too many repetitive rotations at one time can strain the ligaments and muscles in your shoulder.

Ruptured Disc:
See Herniated Disc.


A part of the spine that is also part of the pelvis. It articulates with the ilia at the sacroiliac joints and articulates with the lumbar spine at the lumbosacral joint. The sacrum consists of five fused vertebrae that have no intervertebral discs.

Refers to a lengthwise cut that divides the body into right and left portions.

A lay term indicating pain along the course of a sciatic nerve, especially noted in the back of the thigh and below the knee.

Lateral (sideways) curvature of the spine.

One of the most commonly used orthopedic fixation devices. Screws are designed for different uses and for placement in different types of bone. Screws can be used as single standalone devices, as components of hardware constructs (e.g. plates with screws), or as separate devices complementing other hardware (e.g. interfragmentary screws and plates with screws for fracture fixation).

Self-Tapping Screw:
A screw that cuts its own thread holes in bone as it is screwed into place. Prior to inserting a screw in cortical bone, a guide hole is first drilled that has the same diameter as the core diameter of the screw to be inserted. For a nonself-tapping, a tap is then inserted which cuts the thread holes for the screw. The screw is then inserted. A self-tapping screw has one or more cutting edges at the screw tip that cut the threads holes in the side of the guide hole in which the screw is inserted. Thus, a separate tapping step is eliminated shortening operative time. See non self-tapping screw.

Shoulder Dislocation/Labral Tear:
This is accompanied with intense pain and the shoulder looks out of place or locked in certain positions. It is often followed by muscle spasms, bruises, swelling, numbness and weakness. This injury can often be caused by contact sports, falls, or motor vehicle accidents. Often, your doctor can use certain maneuvers to put the bones back in their position. In some cases, however, the dislocation causes injuries to the soft tissues which require surgical treatment.

The rigid framework of bones that gives form to the body, protects and supports the soft organs and tissues, and provides attachments for muscles.

Soft Tissues:
The ligaments, tendons, and muscles in the musculoskeletal system.

Spinal Canal:
The bony channel that is formed by the intravertebral foramen of the vertebrae and in which contains the spinal cord and nerve roots.

Spinal Column:
See Spine.

Spinal Cord:
The longitudinal cord of nerve tissue that is enclosed in the spinal canal. It serves not only as a pathway for nervous impulses to and from the brain, but as a center for carrying out and coordinating many reflex actions independently of the brain.

Spinal Disc:
See Disc (Intervertebral).

Spinal Fusion:
A neurosurgical or orthopedic surgical procedure that joins two or more vertebrae. This procedure can be at any level in the spine and prevents any movement between the fused vertebrae.

Spinal Stenosis:
Is a narrowing of the spaces within your spine, which can put pressure on the nerves that travel through the spine.

The flexible bone column extending from the base of the skull to the tailbone. It is made up of 33 bones, known as vertebrae. The first 24 vertebrae are separated by discs known as intervertebral discs, and bound together by ligaments and muscles. Five vertebrae are fused together to form the sacrum and 4 vertebrae are fused together to form the coccyx. The spine is also referred to as the vertebral column, spinal column, or backbone.

A form of spinal arthritis that involves inflammation of the vertebrae.

A condition in which one vertebrae body is slipped forward over the other. It is most likely caused by an underlying condition spondylolysis. There are different types of spondylolisthesis, including degenerative, isthmic, dysplastic, traumatic, and pathogenic.

An umbrella term used to describe a degenerative process affecting the vertebrae discs and facet joints that gradually develops with age. The condition can narrow the spinal canal that results in the compression of the spinal cord and nerve roots.

A partial or complete tear of a ligament.

A partial or complete tear of a muscle or tendon.

Stress Fracture:
A bone injury caused by overuse.

Stress Fractures:
Stress fractures are overused injuries. Muscles become fatigued and they are no longer capable of reducing the shock of repeated impacts. When this happens, the muscles transmit the stress to the bones. Over time, those affected bones can no longer repair themselves organically, leading to small cracks or fractures.

Stress Riser:
Places where stress lines from applied forces concentrate within a structure. Breakage is most likely to occur at these places. In long bones or orthopedic plates, for example, stress lines from forces applied at the ends tend to produce uniform cross sectional stress lines. Discontinuities, such as screw holes, redistribute these forces concentrating them close to the holes where fracture is most likely to occur.

Stress Shielding:
The removal of forces or stresses that normally act on bone. Stress shielding eventually leads to osteopenia. A common site for stress shielding is the proximal femoral diaphysis after placement of a femoral prosthesis. The more tightly the stem of the prosthesis fits into the distal medullary canal, the greater the shift of body weight to the prosthetic stem from the proximal femoral cortex. This causes loss of the normal remodeling forces above the level at which the stem is fixated against the endosteal surface of the medullary canal resulting in osteopenia of the proximal femoral diaphysis.

Situated above or directed upward toward the head of an individual.

Synovial Fluid:
A clear, sticky fluid that is released by the synovial membrane and acts as a lubricant for joints and tendons.


Tap, Tapping:
A tap is an instrument used to create threads holes in a hole drilled in bone. Tapping is process of using a tap to create the thread holes. Tapping is used for inserting screws in cortical bone. To insert a cortical screw, a pilot hole is first drilled in the bone that has the same diameter as the core diameter of a screw. The tap is then inserted creating the thread holes for the screw. Finally the screw is inserted. The type of screw inserted is called a nonself-tapping screws. See self-tapping screw.

The fibrous band of tissue that connects muscle to bone. It is mainly composed of collagen.

An inflammation in a tendon or the tendon covering.

Tennis Elbow:
“Tennis elbow” is a common term for a condition aggravated by overuse of the arm, forearm and hand muscles that result in elbow pain. The term came into use because it can be a significant problem for some tennis players. Another common term, “golfer’s elbow;·refers to the same process occurring on the inside of the elbow. Some people have an underlying tendency towards developing these conditions, which then become more painful with overuse.

The chest level region of the spine that is located between the cervical and lumbar vertebrae. It consists of 12 vertebrae which serve as attachment points for ribs.

Shin bone or larger bone of the lower leg.

Refers to a cut that divides the body into superior and inferior portions.


Ulnar Bone:
The longer of the two bones in the forearm.

Ultrahigh Molecular Weight Polyethylene:
UHMWPE. A type of highly durable polyethylene used for replacement of joint surfaces or as entire components in prosthetic joints.
Ultrasound – a diagnostic technique which uses high-frequency sound waves to create an image of the internal organs.

Unipolar Prosthesis:
A prosthesis used for hemiarthroplasties with no across the joint articulating component. Hip and shoulder prostheses are often unipolar. A unipolar device can be of monoblock or modular design. See bipolar prosthesis.


One of the 33 bones of the spinal column. A cervical, thoracic, or lumbar vertebra has a cylindrically–shaped body anteriorly and a neural arch posteriorly (composed primarily of the laminae and pedicles as well as the other structures in the posterior aspect of the vertebra) that protects the spinal cord. The plural of vertebra is vertebrae.

Vertebral End–Plates:
The superior and inferior plates of cortical bone of the vertebral body adjacent to the intervertebral disc.

Generic term for any repair or reconstruction of a vertebral body. Titanium vertebral cages or bone allografts are common ways of replacing damaged vertebral bodies.


The term can refer to thin diameter, fully flexible wires with minimal resistance to bending or thicker diameter wires, such as K-wires, that can be used as rigid fixation devices.


X-ray in plaster. Refers to an x-ray study performed while the examined part is in a cast.

X-ray out of plaster. Refers to an x-ray study performed after the examined part has been removed from a cast.


Yasargil Clip:
A commonly used clip for cerebral aneurysms. The clip has relatively long tongs that permit insertion around the neck of an aneurysm.