Glossary of Hip Terms[A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z ]
Abduction: Movement of a limb or other body part outward and away from the midline of the body.
Acetabulum: Cup-shaped “socket” that is part of the pelvis and holds the head of the femur to make up the hip joint. Three bones fuse together to make up the acetabulum. These are the ilium, ischium, and pubis.
Adduction: Movement of a limb or other body part toward the midline of the body.
Antibiotic spacer: A device made of cement that contains antibiotics and temporarily fills the gap when an infected joint replacement is removed. The antibiotics slowly leech out over a 6-week period in order to eliminate the infection.
Arthroplasty: The removal of a diseased joint and replacement with a prosthetic device, otherwise known as a joint replacement.
Arthroscopy: A minimally-invasive procedure that involves the insertion of a light optic tube (arthroscope) through small incisions around a joint. Images of the inside of the joint are projected onto a screen using the arthroscope, and other tools can be inserted in order to perform microscopic bone removal, assist with determining causes of pain, and evaluate the extent of degenerative changes.
Articular cartilage: Smooth tissue that covers the end of bones where they meet with each other to form joints. The articular cartilage helps to reduce friction as the bones glide against each other.
Atrophy: Muscle wasting that is most often caused by a period of immobilization preventing adequate muscle use.
Avascular necrosis: Bone death due to temporary or permanent loss of blood supply to the bone.
Barlow maneuver: A newborn screening test for developmental dysplasia of the hip. The Barlow maneuver is positive if the hip dislocates posteriorly when it is in an adducted and flexed position.
Biofilm: A collection of one or many different types of microorganisms that stick to each other as well as to a surface.
Bursa: A thin sac filled with lubricating fluid that is located between tissues such as bone and muscle. The bursa reduces friction as the tissues move against each other.
C reactive protein: A protein that is made by the liver and circulates in the blood stream in response to inflammation. Increased levels of C reactive protein (CRP) in the blood can indicate a joint infection.
Capsulorrhaphy: Suturing of a joint capsule in order to prevent recurrent dislocation of articulating surfaces.
Chondrolysis: Rapid and progressive disintegration of cartilage within a joint.
Closed reduction: A procedure performed to set (reduce) the ends of a fractured bone back into place without cutting the skin open to reveal the bone.
Comminuted fracture: A break in the bone that is in more than two pieces.
Complete blood count: A blood test that provides information about the types and amounts of cells in one’s blood. It is often used in orthopedics to determine the amount of white blood cells circulating in the blood. Elevated white blood cell count can be a sign of infection.
Computed Tomography (CT): A form of imaging in which a narrow beam of x-rays rotates around the body in order to generate an image. CT produces a more detailed image than x-ray and is useful for visualizing bone.
Coxa valga: A deformity of the hip where there is an increase in the angle between the femoral neck and femoral shaft.
Deep artery of the thigh: A branch of the femoral artery that travels more deeply along the length of the thigh, carrying oxygenated blood to the muscles of the thigh.
Deep vein thrombosis (DVT): Blood clot that forms in a deep vein of the body. Most DVTs form in the lower legs and are often a result of a prolonged period of immobility.
Displaced fracture: A bone break in which the pieces are not correctly aligned in their original location.
Erythrocyte sedimentation rate: A test that determines the rate of red blood cell settling. When this value is increased, it indicates the presence of an inflammatory response secondary to infection.
Extension: A movement that increases the angle between two body parts. For example, the leg must be completely straightened out in order to extend the knee, thus creating a 0 degree angle between the thigh and calf.
External rotation: Rotation of a body part away from the center of the body.
Femoral acetabular impingement: A condition that results from having an incorrectly shaped femur (thigh bone) or acetabulum (socket). This causes uneven wear on the hip joint over time because the joint is unable to move smoothly.
Femoral artery: A large artery continuing from the external iliac artery that provides the main blood supply to the thigh and lower leg.
Femoral neck: An area of the femur (thigh bone) just below the femoral head, which serves as the “ball” portion of the ball-and-socket hip joint. The femoral neck is a common location for hip fracture.
Femur: Otherwise known as the thigh bone or upper leg bone. The femur is the longest bone in the human body. The proximal femur makes up one side of the hip joint, while the distal femur makes up one side of the knee joint.
Flexion: A movement that decreases the angle between two body parts. For example, the leg is bent at the knee in order to flex the knee, creating a smaller angle between the thigh and calf than when the knee was extended.
Flexion contracture: Inability to straighten a joint actively or passively (with assistance) as a result of structural changes in surrounding soft tissue.
Fluoroscopy: A type if imaging that displays a continuous x-ray on a monitor, much like an x-ray movie.
Foveal artery: A small artery located at the head of the femur (ball) where it meets the acetabulum (socket). It supplies some blood to the head of the femur and is implicated in the prevention of avascular necrosis when other sources of blood supply to the femoral head are lost.
Galleazi’s sign: A physical exam maneuver meant to test for developmental dysplasia of the hip. The exam involves the patient lying on their back with both hips and knees flexed. If the knees are uneven in height, the test is positive
Gout: A form of arthritis caused by deposition of uric acid crystals into the joint space due to high uric acid levels.
Greater trochanter: A part of the femur that can be described as a knob protruding out of the lateral side (outside) of the femur closer to the pelvis.
Hematoma: Spilling and collection of blood outside of a blood vessel due to damage of that vessel.
Hemiarthroplasty: Replacement of half of the hip joint, the femoral component, with a prosthetic. This is in contrast to a total hip arthroplasty which involves replacement of both the acetabulum and femoral head with prosthetics.
Heparin: A blood thinning medication often given after a heart attack or as prophylaxis to prevent unwanted blood coagulation and clot formation.
Herniated disc: When the soft disc between the spinal vertebrae protrudes out due to compression of the vertebrae.
Hip pinning: A surgical procedure involving the placement of three screws through the upper part of the femur to hold a femoral neck fracture together as it heals.
Hip spica cast: A cast that keeps the hips and legs from moving after an operation in order to ensure healing in the correct position.
Hyaline cartilage: A type of cartilage that is made of type II collagen, which makes it considerably strong. Hyaline cartilage lines the acetabulum as well as the head of the femur, providing a smooth and flexible shock-absorbing surface as the two bones glide against each other.
Hyaluronic acid: A major component found in the fluid surrounding the joint that serves to absorb shock and provide lubrication as the joint moves.
Iliofemoral ligament: Fibrous Y-shaped connective tissue that restricts movement of the hip joint. The Iliofemoral ligament connects the anterior superior iliac spine (an area on the lower part of the sacrum) to the intertrochanteric line (an area between the greater and lesser trochanter of the femur).
Internal rotation: Rotation of a body part toward the center of the body.
Inter-positional hip arthroplasty: Placement of a human or animal tissue between the articulating surfaces of the hip joint in order to reduce friction as the joint surfaces glide over each other.
Intra-osseous Hypertension: High blood pressure within the bony matrix.
Ischemia: an inadequate blood supply to an organ or part of the body.
Ischiofemoral ligament: Strong fibers that connect the ischium of the pelvis to the femoral head. The ischiofemoral ligament prevents hyper-mobility and helps to stabilize the joint.
Joint space narrowing: Loss of cartilage between the two bones of a joint.
Krischner (K) wire: A sterilized stainless steel wire used to guide many orthopedic procedures. K wires help to keep bone fragments in place.
Labrum: A rim of soft tissue that surrounds the acetabulum, increasing the surface area of the articulating surface. The labrum protects the joint surface and provides stability to the joint.
Lateral circumflex femoral artery: A branch of the femoral artery that provides blood to the front (anterior) and middle (medial) compartments of the thigh.
Lesser trochanter: A pyramid shaped eminence that protrudes from the proximal and medial side of the femur below the femoral head.
Ligament: A connective tissue structure that connects two bones.
Magnetic Resonance Imaging (MRI): An imaging technique that uses strong magnetic fields to generate images of the internal structures of the body.
Medial circumflex femoral artery: An artery of the upper thigh that supplies blood to the femoral neck. Damage to this artery as a result of fracture may cause avascular necrosis.
Nerve conduction study: A test that measures the speed of an electrical impulse through a nerve. The results help determine if there is a problem with the function of a particular nerve. A nerve conduction study is also called electromyography (EMG)
Needle aspiration: The insertion of a needle into tissue in order to drain fluid and/or collect a sample of fluid for laboratory testing.
Non-comminuted fracture: A bone fracture with a single fracture line that is in 2 pieces with no other bone fragments present.
Non-displaced fracture: When the pieces of fractured bone on either side of the fracture line are correctly aligned in their original position.
NSAIDs: Non-steroidal anti-inflammatories are a class of drugs that are used to reduce fever, pain, and inflammation.
Obturator artery: An anterior division of the internal iliac artery that supplies blood to the medial thigh.
Open reduction: Putting a displaced joint or fracture back into alignment via surgical exposure of the bone.
Ortolani maneuver: A newborn screening test for developmental dysplasia of the hip. The Ortolani test is positive if a “clunk” sound is heard when anterior pressure is applied to the greater trochanter with the hip in an abducted position.
Osteonecrosis: Death of bone tissue due to a lack of blood supply.
Osteophyte: Also known as a bone spur, an osteophyte is a bony growth that can cause pain by impinging on other structures. It can also limit range of motion of a joint depending on its size and location.
Osteoporosis: Loss of the density and strength of bone that usually occurs as we age.
Pavlik harness: A device used to treat developmental dysplasia of the hip in infants. The harness keeps the hips in a flexed and abducted position as the child grows.
Petrie Cast: A cast covering the entirety of both legs with a bar in the middle connecting the legs in a “spread” position. A petrie cast is used in the treatment of Legg-Calve-Perthes disease.
Prosthetic: A man-made device made of various materials that is meant to replicate the size, shape, and function of an existing body part.
Pseudogout: An inflammatory arthritis that occurs due to the deposition of calcium pyrophosphate dihydrate crystals within the joint cartilage.
Psoriatic arthritis: A type of joint inflammation that can occur with or without psoriasis.
Pubofemoral ligament: A sturdy yet flexible soft-tissue structure that attaches the pubic bone, a part of the acetabulum, to the femoral neck. This ligament helps to prevent excessive range of motion, keeping the hip joint in place.
Pulmonary embolism (PE): A blood clot that becomes dislodged and stuck in the blood vessels of the lungs. This disrupts oxygenation of blood, leading to a loss of oxygen supply to the bodies organs. A pulmonary embolism is fatal if not treated.
Reactive arthritis: An immune-medicate arthritis that can sometimes occur 2-4 weeks after an acute bacterial infection of the gastrointestinal or genitourinary tract.
Referred pain: Pain in one part of the body that indicates there is something wrong in another part of the body. This displacement of pain occurs due to the pathway that nerve fibers signaling pain travel throughout the body.
Sciatic nerve: The largest nerve in the human body. The sciatic nerve supplies motor and sensory innervation to the back of the lower extremity, running from the hip through the buttock area and down to the foot. It gives off multiple branches as it courses through the leg.
Septic arthritis: An infection within the joint that causes arthritic symptoms such as pain, limited range of motion, and swelling.
Spica cast: A type of cast that covers one or both legs and the waste area. The leg casts are connected in a wide-legged stance with a bar in the middle, resembling a capital letter “A”.
Spinal stenosis: Narrowing of the spinal canal where nerves travel. Spinal stenosis can lead to nerve compression causing symptoms of pain, numbness, and tingling at and below the level of the spinal cord where stenosis has occurred.
Stress fracture: Small cracks or points of weakness in a bone as a result of repetitive use.
Subchondral cyst: A fluid-filled sac that develops under the cartilage of a joint surface as a result of abnormal friction and joint loading.
Subchondral sclerosis: Hardening of the bone that lies just beneath the cartilage
Subluxation: Partial or temporary dislocation of a joint that is either reduced completely back into its original location or remains partially dislocated.
Tendon: A piece of sturdy soft tissue that is flexible and anchors muscles to bones.
Transverse acetabular ligament: A sturdy piece of soft tissue that covers the lower portion of the acetabulum, and makes up part of the labrum.
Trendelenburg Gait: An abnormal way of walking where one hip drops with each step, resulting in unequal loading of force on the legs.
X-ray: An imaging technique that uses a beam of radiation and is good for visualizing bone.