Medical Apparatus: Imaging Guide to Orthopedic Devices

Glossary: R - T



Terms: Click below for the desired term







Medical Devices, Medical Procedures, and Foreign Bodies:
Abbreviations, Acronyms, and Definitions

by Tim B Hunter, MD, MSc and Mihra S. Taljanovic, MD, PhD



radiopaque.  Term used to describe the ability of a substance to absorb x rays and appear opaque (white) on radiographs.

rayon.  Any of a group of smooth textile fibers made in filament and staple form from cellulose material by means of extrusion through minute holes.

RDA. Rude, dismissive, and aggressive, a term sometimes applied to poor communications between physicians or between physicians and patients.

ream. The process of enlarging a space or cavity, usually the medullary space, in a bone so a prosthesis or rod, such as a femoral nail, can be inserted.

REBOA. Resuscitative endovascular balloon occlusion of the aorta, a technique to control noncompressible intracavitary hemorrhage below the diaphragm.

Reconstruction breast prosthesis.  A breast implant (prosthesis) used to reconstruct a breast after mastectomy.

reconstruction plate.  A type of orthopedic fixation plate that is notched between the holes, allowing it to be bent or contoured in three planes. These plates are commonly used to accommodate the complex anatomy of pelvic fractures.

reconstruction rod.  A type of orthopedic rod used to treat fractures of the femoral neck, intertrochanteric, or subtrochanteric areas. These rods have proximal locking holes oriented to allow screws to be placed into the femoral neck and head.

REMS. Risk evaluation and mitigation strategy, an evaluation process used by the FDA for certain medicatons with serious safety concerns. It should not be confused with the rapid eye movements (rems) stage of sleep.

replacement (Joint Replacement). A generic term often used synonymously with a joint prostheses or joint arthroplasty.

resection (excision) arthroplasty. Removal of joint surfaces to treat severe osteoarthritis, joint deformity, or joint infection. No implant is usually placed at the resected joint.

resin. A solid or semisolid compound obtained from a plant by exudation. Resins have widespread use in varnishes and in medical applications, often mixed with other substances.

resin base acrylics.  Biomaterials used in dentures, removable orthodontic appliances, bite guards,  temporomandibular joint orthotic appliances, temporary crowns or bridges, and denture teeth.

restoration (dental). Another term for dental fillings.

retaining plate.  An orthodontic appliance.

Retention suture bridge. An apparatus for controlling and distributing tension on retention sutures used to close the abdominal wall. It consists of a strong plastic truss bridge containing a capstan at its middle making it easier to adjust each retention suture and distribute stress more widely over a wound.

reverberation bands (ultrasound).  A type of ultrasound artifact in which bright parallel lines or bands occur at regular intervals on an ultrasound image.

reverberation pseudomass.  An ultrasound artifact in which multiple reverberating echoes from a gas-filled or fluid-filled structure can simulate a mass.

Reverse total shoulder arthroplasty (prosthesis). This shoulder arthroplasty (replacement) has the prosthetic articular socket and prosthetic humeral head (metal ball) switched from their normal positions in the scapula and humerus, respectively. In a reverse total shoulder replacement the articular socket now sits in the upper portion of the humerus and the metal ball now sits in the former location of the glenoid fossa. This form of arthroplasty is used for patients with a totally torn rotator cuff or a previously failed shoulder joint prosthesis. This prosthesis allows the patient to use the deltoid muscle to lift the arm.

RFID. Radiofrequency identification chip.

RIA. Reaming (of bone) and aspiration.

ring artifact.  A type of computed tomographic artifact usually caused by a faulty detector producing rings or concentric circles on computed tomographic images.

ringdown artifact.  See comet-tail artifact. See Gimber, 2016 for a more complete discussion of comet-tail versus ring down artifact.

RLI. Radiology Leadership Institute.

RND.  Radical neck dissection.

road rash.  Term  used by emergency  room and trauma team personnel to describe the gravel, broken glass, dirt, and other debris that becomes embedded in the skin and soft
tissues of motor vehicle, bicycle, moped, motorcycle, and pedestrian accident  victims. Some of the debris, such as glass and gravel, is radiopaque and will be visible on conventional radiographs.

ROM.  Removal of metal, range of motion, read only memory, range of movement, reduction of movement, rupture of membranes.

ROP.  Removal of pins, plaster.

round CT static artifacts.  A film related artifact. Round computed tomographic film static artifacts are spot-like or smudge-like areas of low opacity on film. They are created by static electric discharges at points of contact between film and cassettes.  These are rarely seen in the modern era of digital displays and filmless radiology departments.

RPG.  Retrograde percutaneous gastrostomy.

RPM. Remote patient monitoring.

RPN.—resident progress note. There is no standard abbreviation for “attending physician progress note,” since, until recently, attending physicians were not accustomed to writing progress notes.

RSA. Reverse (total) shoulder arthroplasty.

RTSA. Reverse total shoulder arthroplasty.

RUA.  Reduced under  anesthesia.

rubber.  Substance defined by the American Standards for Testing and Materials (ASTM) as “a material which at room temperature can be stretched repeatedly to at least twice its original length and upon release of the stress, returns immediately  with force to its approximate original length.”

Rush pin.  A type of orthopedic fixation pin with sled-runner tip on one end and a hook on the other end.

Rush rod. An unreamed intramedullary rod with a chisel-like tip and a hook on its other end. It is most commonly used in fibular shaft fractures.

RWE. Real-world evidence. The 21st Century Cures Act directs the Food and Drug Administration (FDA) to consider how best use real-world evidence for assurance of device safety and effectiveness while facilitating access to new technologies (Resnic, 2018).

Rx.  Treatment.  Prescription.


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Saf-T Coil.  A type of intrauterine contraceptive device.

Sage nail.  A solid nail used for intramedullary fixation of the radius and ulna.

Sampson nail (rod).  A hollow cylindrical rod with multiple external flutes.  It is used to treat femoral shaft fractures.

SAPF.  Simultaneous anterior and posterior (spinal) fusion.

Sarmiento brace (splint, orthosis). A cylindrical brace applied around a fracture site compressing the soft tissues and stabilizing the fracture for better healing. The brace is often of bivalve design and is most commonly used to treat humeral shaft fractures.

SATL.  Surgical Achilles tendon lengthening.

SB. Sublaminar band, a metallic band placed under the lamina as part of spine surgery.

SBCE. Small bowel capsule endoscopy.

SB Charite III Dynamic Disc Spacer. A type of spinal total disk replacement (TDR).

Schanz screw.  A type of screw specifically used with an external fixator for external fixation of fractures, named after Alfred Schanz (1868-1931) a German orthopedic surgeon.

Schneider nail.  A four-flanged intramedullary nail used for femoral shaft fractures.

Scott inflatable prosthesis.  A type of penile prosthesis.

SE.  See Starr-Edwards (heart) valve.

Seldinger technique.  A percutaneous technique introduced in 1953 by the Swedish radiologist Sven-Ivar Seldinger (1921-1998) for the placement of catheters and tubes.  It avoids the need for a surgical cut down and employs the use of a guide wire introduced through a hollow needle.

self-tapping screw. A screw with one or more cutting edges at the screw tip which cuts thread holes when the screw is screwed into place in a guide hole that has previously been drilled.

Sengstaken-Blakemore tube.  A complex device for controlling bleeding esophageal varices.  There are three lumina, one of which is used to inflate a stomach balloon for holding the device in place and for tamponading bleeding vessels in the cardia of the stomach. A second lumen is used for inflating a long balloon positioned in the distal portion of the esophagus to compress bleeding esophageal varices.  The third lumen is used for aspiration of stomach contents.

shape memory alloy (SMA).  An alloy that permits one to potentially design an implant that can be changed to its desirable body form by a well-controlled heating process.

Sherman plate.  A type of fracture fixation plate.

side-lobe/grating lobe  artifact.  An artifact in which several additional sound beams may be located outside the main axis of the diagnostic ultrasound beam.

Sideris patch.  A “patch” used to close an atrial septal defect.

Silastic rubber.  Trade name of Dow Corning (Midland, MI) for a condensation polymer.  It is a type of soft, flexible silicone rubber.

silicone.  A generic term for organic silicon compounds polymerized for use as oils, polishes, and rubber like materials.

Silicone rubber.  A trade name of Dow Corning (Midland, MI) for certain rubber polymers made from polydimethyl siloxane, which is polymerized by a condensation process. The term silicone rubber is also used generically for a multitude of rubber like polymers derived from organic silicon compounds.

Silk  tube.  A type of feeding tube.

(Simon) Nitinol filter. A type of inferior vena cava filter.

simultaneous bidirectional flow artifact.  A Doppler ultrasound artifact in which there is the appearance of bidirectional simultaneous flow on both sides of the zero baseline.

sliding nail-plate device.  Any type of device used to treat femoral neck and intertrochanteric fractures in which the device has a side plate and a tunnel through which a lag screw or pins can glide to compensate for impaction at the fracture site.  See also dynamic hip screw.

SLIC (scapholunate intercarpal) screw fixation system. A system to anatomically reduce and fixate two bones or portions of bones. It is specifically used in the repair of scapholunate ligament injury, scapholunate reduction, lunotriquetral ligament repair, lunotriquetral reduction, and carpal instability.

SMA.  Superior mesenteric artery, shape memory alloy.

Small-Carrion.  A type of semi-rigid penile prosthesis.

Smart (Toe) implant. The Smart implant is a product of Stryker specifically designed for interdigital fusion of fingers or toes and other small bones.

Smeloff-Cutter valve.  A type of prosthetic heart valve.

Smith-Hodges.  A type of pessary.

Smith-Peterson cup.  A type of metal cup placed on the surgically reamed femoral head in cases of fracture or avascular necrosis.

Smith-Peterson nail.  A type of flanged nail for treating fractures of the femoral neck.

SMP. Shape-memory polymer, a substance that can change shape in response to an external stimulus like temperature.

Snap-Lock.  A type of vascular access port.

SNR.  Signal to noise ratio.

SOAP.  A standardized method for recording patient progress notes: S = subjective patient complaint, O = objective findings, A = assessment of the patient, P = plan of action.

soft  point bullet.  A bullets that has some of the lead core exposed at the tip.  Soft point bullets are designed to deform into a mushroom shape in tissue to maximize tissue damage.

Somi brace.  A type of cervical spine brace.

S/P.—status post. This term is frequently seen on radiologic requisitions. It means the patient had something done in the past, either recent past or distant past; e.g., “s/p hip arthroplasty” simply means the patient had hip replacement surgery sometime in the past.  Unfortunately, s/p carries no time connotation and is a nonspecific, often non-useful term.

SPECT. Single-photon emission computed tomography, a nuclear medicine tomographic cross-sectional imaging technique using gamma rays from radiopharmaceuticals.

SPIE.  Legally known as The Society of Photo-Optical Instrumentation,SPIE is a leading group in the planning of standards and the development of electro-optical systems. 

spinal board. See trauma board.

spinal column stimulator.  An electronic device with leads implanted in the epidural space, the dura, or the subarachnoid space to provide an electrical signal for the relief of pain or muscle spasticity. These are sometimes mistakenly called a TENS (transcutaneous [transepidermal] electrical neural stimulation) unit. Similar devices may be used for stimulation of the vagus nerve in the neck or the sacral plexus in the pelvis.

SR.  Slow-release medication, sinus rhythm, or “see report.”

Stabilimax NZ system (Applied Spine Technologies). A metallic posterior lumbar spine dynamic stabilization system using a spring mechanism.

stainless steel.  A common metallic biomaterial.  It is a steel alloy with a minimum of 11% chromium content by mass.  Stainless steel is known for its resistance to corrosion and rusting compared to ordinary steel. 

STAR Ankle (Scandinavian Total Ankle Replacement). A total ankle replacement (TAR) system, a 3-piece mobile bearing total ankle arthroplasty, product of Small Bone Innovations, Inc.

Starr-Edwards valve, SE valve.  A type of prosthetic heart valve.  Its ball-cage design was one of the first successful prosthetic heart valves.  It was introduced in 1960 by Albert Starr (1926- ), a young thoracic surgeon, and Lowell Edwards (1898-1982), a highly successful engineer and inventor.

STAT, stat.  Abbreviation for statim, which means “immediately” in Latin.  It is supposed to indicate an emergency of the most extreme kind. Unfortunately, this term has been abused by physicians and others who desire a radiologic study, laboratory  procedure, or patient  consultation performed quickly for their own convenience or for the patient’s convenience rather  than for an emergency  situation.  Because of this abuse, the term has little significant meaning in many radiology, pathology, and emergency departments.

Steffee device.  A type of posterior spine fixation apparatus that uses flat plates connected to pedicle screws.

Steinman (Steinmann) pin. A wide diameter pin commonly used for fixation of fracture fragments during fracture reduction and skeletal traction, especially in the femur and tibia. It is named after Fritz Steinmann (1872-1932), a Swiss surgeon.

St. Jude valve, St. Jude bileaflet prosthesis.  A type of prosthetic heart valve.  See Lillehei- Kaster valve.

Strecker stent.  A flexible balloon-expandable tantalum endovascular stent.

stress loading. Increase in bone density due to altered stress distribution to native bone from an implant, most commonly seen with a hip arthroplasty stimulating thickening and sclerosis in the femoral cortex near the tip of the femoral stem of the arthroplasty.

stress shielding. Reduction in bone density from removal of normal stress from the bone by an implant, most commonly seen in the humerus from the humeral stem of a shoulder prosthesis or in the femur from the femoral stem of a hip prosthesis.

subdural drainage catheter.  A catheter commonly placed to diminish subdural hematoma re-accumulation and to allow the brain to re-expand.

sump drain.  A type of drainage that provides a constant low level of suction.  Modern sump drains often have three lumina.  One lumen allows for drainage of fluid, the second allows filtered air to be sucked into the drainage bed to provide pressure for drainage, and the third is used to irrigate the wound bed.

suprapubic cystostomy.  A catheter placed through the anterior pelvic wall directly into the bladder.

susuk (Malaysian) charm needles. Metallic talismans (needles or pins) inserted subcutaneously to treat a present condition or protect against future injury. It is a hidden practice that may be seen in Southeast Asia, especially Malaysia, Brunei, Singapore, Thailand, and Indonesia. The most common site of insertion is the facial region.

suture anchor (screw). A device for the fixation of tendons and ligaments to bone. It often consists of a screw portion that is inserted into the bone and an eyelet portion through which the suture passes. Suture anchors can be constructed from metals or bioabsorbable materials.

Suzuki frame. A device for stabilizing complex intra-articular finger fractures. Rubber bands generate traction between two Kirschner (K-wire) wires placed into the bone on either side of the fracture.

Swan-Ganz catheter.  A registered trade name of Baxter International, Inc. (Deerfield, IL).  This term has come to represent any type of multi-lumen central venous catheter used for measuring hemodynamic pressures and cardiac output. The tip of the catheter is usually placed in a proximal pulmonary artery branch and may be temporarily wedged more distally for measurement of pulmonary venous or left atrial pressure. The first clinical use of such a catheter was described by H. J. C. Swan, Willard Ganz, and colleagues in 1970.

Swanson prosthesis.  A type of prosthesis used in small joints, such as in the fingers and toes.

Sx.  Signs, symptoms.

Synchromed.  A type of vascular access port.

syndesmotic screw.  An orthopedic screw that is placed across the distal tibiofibular joint parallel and 1–2 cm proximal  to the ankle joint to stabilize the joint after disruption of the ankle syndesmosis. There may be multiple (more than one) syndesmotic screws used to treat a given patient.


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TAA. Total ankle arthroplasty.

TACE. Transarterial chemoembolization.

TAE.  Transcatheter arterial embolization.

tantalum.  A noncorrosive, malleable metal found in some prosthetic devices. As a mesh, it was formerly used to reinforce wound closures.

tap. A tool to create thread holes in a previously drilled pilot hole. In regard to orthopedic practice, tapping of cortical bone is used for the later insertion of cortical screws into the tapped pilot hole. Such screws used are termed nonself-tapping screws.

TAR. Total ankle replacement.

TARA.  Total articular replacement arthroplasty.

TAVR. Transcatheter aortic valve replacement.

TCP/IP.  Transmission control protocol/Internet protocol, a network standard commonly used to transmit data, especially on the Internet.

TCu  (Copper T).  A type of intrauterine contraceptive device.

TDR. Total disk replacement.

TEA. Total elbow arthroplasty.

Teflon (polytetrafluoroethylene, PTFE, polytef).  The best known of the fluorocarbon polymers, a material resulting from substituting the hydrogen  atoms of polyethylene with fluorine.

Tenckhoff catheter.  A peritoneal dialysis catheter.

TENS.  Transcutaneous electrical neural stimulation.  See also spinal column stimulator.  TENS units stimulate nerves through the skin with two or more electrodes.  Spinal column stimulators directly stimulate the spinal column or nerve roots exiting the spinal column, though the two terms may be loosely applied and used interchangeably. 

Tension band wiring.  A type of orthopedic wiring used to absorb tension and apply compression to bony fragments at a fracture site.

TESS shoulder system. Total Evolutive Shoulder System (Biomet). A total shoulder arthroplasty (TSA) designed to reduce the amount of bone removed. It does not have a traditional long metal stem for the humeral component. TESS can also mean the Toronto extremity salvage score which assess physical function following limb salvage for bone and soft tissue sarcoma.

TFE.  Tetrafluoroethylene, the chemical compound used to manufacture Gore-Tex, Teflon, and other fluorocarbon polymers.

TFN. (Titanium) trochanteric fixation nail system. A femoral fixation system with a helical blade extending from the intertrochanteric region into the femoral neck and head combined with a long or short femoral intramedullary nail.

THA.  Total hip arthroplasty.

thermoplastic. A plastic material that becomes pliable or moldable upon heating and solidifies on cooling. A thermoplastic may be reheated and reshaped more than once.

thermoset. A plastic material that can be shaped only once.

THJR.  Total hip joint replacement.

TLIF. Transforaminal lumbar interbody fusion. See NuVasive.

thoracostomy tube.  Another term for a chest tube. It is used to drain pleural fluid collections or re-expand the lung in cases of a pneumothorax.

Thoratec.  A type of ventricular assist device.

Thorotrast.  Thorium dioxide, formerly used as a radiologic contrast agent. It was discontinued in the 1950’s because of its carcinogenic properties. Thorium is a radioactive element and emits alpha particles.

THR.  Total hip replacement; through-transmission artifact, an ultrasound artifact created when tissue that lies deep to fluid-filled structures appears more echogenic than normal.

TightRope Syndesmosis. An ankle syndesmotic injury fixation system using a fiber wire loop tensioned and secured between metallic buttons on the distal tibial medial cortex and the distal fibular lateral cortex.

TIPS(S).  Transjugular intrahepatic portosystemic shunt or stent.

TIS device. Thoracic insufficiency syndrome (TIS) device for skeletally immature patients with severe, progressive spinal deformity or thoracic cage deformity hindering normal respiration or lung growth.

tissue compatibility.  A general descriptive term describing the compatibility of a prosthesis or device for use in human tissues.

titanium.  Metal used as an implant material because of its high corrosion resistance and relatively low density.

titanium interbody spacer (TIS).  See vertebral cage.

TJA. Total joint arthroplasty.

TKA.  Total knee arthroplasty.

TKR.  Total knee replacement.

TLD.  Thermoluminescent dosimeter, a device used to measure ionizing radiation.

TLIF. Transforaminal lumbar interbody fusion.

TLSO brace. Thoracolumbar sacral orthosis brace. Also known as a Boston brace. The TSLO brace is a form fitting brace which limits back movement. It is worn around the thoracolumbar region to improve posture and to protect and stabilize the back for patients with vertebral injuries or after vertebral surgery. It is a rigid brace composed mainly of plastic. See TLSO braces.

TMD. Temporomandibular joint dysfunction.

TNTC.  Too numerous to count.

TOEFIT-Plus. A modular arthroplasty system for replacement of the large toe metatarsophalangeal joint (first metatarsophalangeal joint). It can be configured for either total replacement of the joint or for partial (hemiarthroplasty) replacement of the joint. The non-cemented implant is fixed into the patient's host bone by a self-tapping threaded taper.

tombac (tombak). A brass alloy with high copper content and 5-20% zinc content. It may also contain small amounts of tin, lead, or arsenic and is used for medals, ornaments, and in some munitions.

TomoFix Osteotomy System (Synthes). A fixation plate system designed to provide stable fixation of osteotomies close to the knee including lateral and distal osteotomies in the femur and in the tibia.

TPN.  Total parenteral nutrition.

tracheostomy tube.  A tube directly inserted into the trachea through the anterior tracheal cartilage. It bypasses the larynx and pharynx and is used for patients in need of long term mechanical ventilation.

TRAM flap.  Abbreviation for transverse rectus abdominis muscle flap, a surgical procedure in which a portion of the abdominal wall is used to cosmetically construct a breast after mastectomy.

trauma board. Also known as spinal board, (long) spine board, longboard, spineboard, backboard. A patient handling device, especially applicable for trauma patients, for transportation to the hospital. The patient is strapped onto a long, wood or plastic radiolucent board with handles for carrying. The board transports the patient in a safe fashion while stabilizing the spine and internal organs protecting them from further injury. Trauma boards are often used with cervical collars and padded side head supports. Patient radiographic studies are sometimes performed with the patient lying on a trauma board.

tribocorrosion. A process of material degradation from the combined effects of corrosion and wear.

triflanged nail.  A type of fixation nail used for intracapsular hip fractures.

TSA. Total shoulder arthroplasty.

TSR.  Total shoulder replacement.

T-tube drain.  A type of traditional gravity drain configured in a T shape.  T-tubes are most often used for common bile duct drainage.

tubular plate.  A fracture fixation plate with a circular profile. For example, a one-third tubular plate represents one-third of a cylindrical circumference. Tubular plates are thin, self-compressing, and easily bent to adapt to varying fracture conditions.

TWA. Trans World Airlines (1925-2001). In the context of medical apparatus TWA signifies total wrist arthroplasty.

twiddler’s syndrome.  A situation in which a patient “twiddles” with his or her pacemaker pack, twisting it around in its pocket. Such an action can lead to fractured wires, pacemaker malfunction, or retraction of the pacemaker leads.

Tx.  Treatment, therapy, transplant.


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Tim Hunter

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