Medical Apparatus: Imaging Guide to Orthopedic Devices

Glossary: J - M



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



Jackson-Pratt drain.  A flat, fenestrated, closed-wound surgical drain.

Jarvik heart, Jarvik 7, Jarvik 2000. A pneumatically driven biventricular device invented at the University of Utah.  It completely replaces the native heart within the pericardial sac.

JCAHO.  Joint Commission on Accreditation of Healthcare Organizations.  Also known as the “Joint Commission.”

jejunostomy tube.  A tube surgically or percutaneously placed into the jejunum through the anterior abdominal wall and used for long-term administration of feedings.

Jewett nail and Jewett plate.  Materials used together for internal fixation of an intertrochanteric hip fracture.

JHP. Jacket hollow point bullet.

JISRF. Joint Implant Surgery & Research Foundation (JISRF).

JJ stent (double J stent).  An internal drainage catheter with curves at both ends. It is sometimes used for percutaneously placed ureteral stents.

Jonas penile prosthetic implant.  A type of penile prosthesis.

JP, JP-drain, JP-tube.  See Jackson-Pratt drain.

J-tube.  Jejunostomy tube.

J wire.  A common angiography guide wire with a curved, j-shaped end.


Kalke-Lillehei valve.  See Lillehei-Kaster valve.

Kaneda device.  A spinal fixation device designed to facilitate one-stage treatment of thoracolumbar lesions.

Kevlar. A type of polyamide synthetic fiber developed by DuPont. It has high tensile strength to weight ratio being 5 times stronger than steel making it suitable for many commercial applications like tires, racing sails, and body armor.

Kidner procedure. Excision of the accessory navicular bone with reattachment of the posterior tibial tendon to the undersurface of the remaining navicular bone with a suture anchor.

Kimray-Greenfield (K-G) filter.  A type of inferior vena cava filter used to prevent clot propagation to the lungs.

Kirschner wire (K-wire or K wire).  A wire commonly used for fixation of fracture fragments during fracture reduction and skeletal traction. K-wire has become a generic term for any type of wire or pin fixation of a fracture. The Kirschner wire was developed by Martin Kirschner (1879–1942), a German surgeon, who introduced the use of wire skeletal traction in 1909.

Kiva VCF Treatment System (Benvue). A vertebroplasty system using a unilateral transpedicular percutaneous approach in which a PEEK cylindrical implant is placed into the vertebral body using a guidewire The PEEK implant forms a hollow spiral tube in the vertebral body into which vertebroplasty cement is instilled. The implant and hardened cement help to restore vertebral height and remain within the vertebral body.

Knodt rod.  A type of orthopedic fixation rod used for spine reconstruction.

Knowles pin.  A type of orthopedic fixation pin.

KTx.  Kidney transplant.

Kuntscher nail.  A type of intramedullary nail for the fixation of fractures.  The first practical use of “rods” and “nails” to treat long bone fractures  was performed by Gerhard Kuntscher (1900–1972) in 1940 while he served in the German army.

Kurosaka screw.  A short, broad, headless orthopedic screw designed to anchor anterior cruciate ligament grafts in the metaphysis of the tibia and femur.

K-wire of K wire.  See Kirschner wire.

Kyphoplasty. A variation of vertebroplasty. Kyphoplasty uses a balloon that is inflated in the treated vertebral body to create a cavity within the vertebral cancellous bone. The vertebroplasty cement is instilled directly into the newly created cavity.


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LAC.  Left  atrial catheter.

lag screw.  An orthopedic screw that provides compression across a fracture line.  A better term is interfragmentary screw

Lane  plate.  A metallic bone plate used for fracture fixation.

latex.  A suspension in water of particles of natural or synthetic rubber or plastic; used in rubber goods, adhesives, and paints.

LCP, LCDCP, LCD.  Low-contact dynamic compression plate, a type of orthopedic compression plate designed to preserve periosteal blood supply.

LCME. Liason Committee on Medical Education.

LCW. Lateral closing [tibial] wedge osteotomy.

LDR. Lumbar disk (disc) replacement.

Leinbach prosthesis.  A proximal femoral implant replacement device for the femoral head, neck, and trochanteric regions.

Le Veen shunt. A peritoneal jugular shunt designed to drain ascitic fluid from the peritoneal cavity to the central venous system.

Levin tube.  A small-bore nasogastric tube.

LGM, Vena  Tech/LGM.  A type of inferior vena cava filter.

LIF. Lumbar interbody fusion.

Lifeport.  A type of vascular access port.

light-bulb effect.  A type of computed radiographic artifact. The lower, outer portions of an image appear darkened relative to the remainder of the image because of backscattered radiation entering the photostimulable phosphor imaging plate from the patient’s bed or other object.

Lillehei-Kaster valve, Lillehei-Nakib valve, Kalke-Lillehei valve, St. Jude bileaflet prosthesis.  Types of prosthetic heart valves developed under the tutelage of C. Walton Lillehei (1918–1999).  Lillehei is known as the father of open-heart surgery for his pioneering work in developing open-heart surgery techniques, artificial heart valves, and heart pacemakers. In 1955, Richard A. DeWall and Lillehei developed the first practical heart-lung machine.

linear artifact.  A type of computed tomographic artifact seen at the edges of tissues with different attenuation, such as the junction of the dome of the liver and the lung base.

Lippes loop.  A type of intrauterine contraceptive device.

LISS plate. Less invasive stabilization system plate. The screw holes in a LISS plate are round and threaded. Its unicortical screws are locked onto the plate. A LISS plate does not have to be in close contact to the bone causing less damage to the bone and its blood supply.

liquid adhesives (glue).  Glue-like biomaterials sometimes used to treat arteriovenous malformations, high-flow vascular fistulas, and brain tumors.

LLIF. Lateral lumbar interbody fusion.

LMS. Lateral mass screw.

locking (interlocking) screws.1. Screws used with intramedullary rods to “lock” the rods in place for control of fracture-fragment rotation and shortening. 2. Screws with a threaded screw head that lock into a fixation plate by engaging threads in the plate screw holes.

LOCM. Low osmolality contrast material.

longboard. See Trauma Board.

long spine board. See Trauma Board.

Lottes nail.  A triflanged intramedullary nail used for closed fixation of tibia fractures.

LPS. Limb Preservation System. LPS is a trademark of DePuy Synthes.

LRTI. Ligament reconstruction tendon interposition.

LSB. Long spine board. See Trauma Board.

LSS. Limb sparing surgery.

Lucite. Proprietary name (E.I. DuPont de Nemours and Co.) for polymethyl methacrylate. Often used generically for any transparent plastic, but it is more properly used for polymerized methyl methacrylate which is transparent and resistant to weathering.

Luque rods (wires).  An orthopedic fixation system used for spine surgery. It provides segmental  posterior  stabilization  of the lumbar or thoracic  spine by means of sublaminar wires linked to anchor  rods.

LVAD.  Left ventricular assist device. See ventricular assist device.


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MacroPort.  A type of vascular access port.

Maglinte tube.  An intestinal tube placed in the duodenum or jejunum for performing enteroclysis. It has an expandable balloon used to occlude the bowel lumen to prevent reflux of fluid into the stomach.

magnetic susceptibility artifact. A form of chemical shift artifact in which artifacts may be attributable not to a difference in the frequency precession  of fat and water but to the magnetic  susceptibilities of different materials, inhomogeneity in the static field, the presence  of magnetic  materials, or all three. Magnetic artifacts are projected along the frequency-encoding axis and may have comet-tail appearances, depending on the shape of the magnetic inhomogeneity.

Malaysian charm needles (susuk). 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.

Malecot catheter.  A catheter with a bulbous tip composed of two or four wings.

malleolar bone screw.  A type of cortical bone screw with a self-tapping  thread.

mammary prosthesis.  A breast augmentation reconstruction implant.

MAR. Metal artifact reduction algorithm or technique.

Marmor hemiarthroplasty.  A type of hemiarthroplasty used in the knee.

Massie nail.  A telescoping nail-plate assembly used to treat intertrochanteric hip fractures.

MAST  suit.  Military anti-shock trousers.

MAUDE. Online FDA database Manufacturer and User Facility Device Experience.

McGlaughlin nail.  A nail designed for use with a side plate for fixation of intracapsular and intertrochanteric hip fractures.

McLean Ringer tube.  A type of feeding tube.

MDIC. Medical Device Innovation Consortium.

MDMA. Medical Device Manufacturers Association.

MDP. Methylene diphosphonate, a pharmaceutical product which is linked to the isotope of technetium 99mTc and used most commonly as a nuclear medicine bone-imaging agent.

MDR. Medical device reporting (for manufacturers).

MDS. Medical device postmarket surveillance.

MedSun. Medical Product Safety Network.

MedWatch. The FDA safety information and adverse event reporting program.

MEMS. Micro-Electro-Mechanical-Systems (MEMS), which refers to micro-technology devices based on nanodevices.

Medtronic Hall valve.  A type of prosthetic heart valve.

Mentor GFS.  A type of penile prosthetic implant.

Mentor “3-piece.”  A type of penile prosthetic implant.

metaglene. Glenoid baseplate portion of a reverse total shoulder arthroplasty (RTSA or RSA).

Methacrylate.  See poly (methyl methacrylate).

metal. A metal is a solid material which is usually hard, shiny, malleable, fusible, and ductile. It often has good electrical and thermal conductivity. Common metals include iron, gold, silver, copper, cobalt, aluminum, titanium, and zinc.

methyl methacrylate. See poly (methyl methacrylate).

metallosis. The build-up of metal debris in soft tissues, most often from gradual wear and tear with shedding of tiny metal particles in joint prostheses. This condition can lead to osteolysis, granulation tissue formation, and prosthesis failure. A somewhat related condition is particle disease which is caused by shedding of tiny particles, usually polyethylene, leading to bone destruction and inflammatory tissue formation with eventual joint prosthesis failure.

metal-on-metal disease. A condition similar to particle disease and metallosis. Small particles of metal are released from joint prostheses with wear, inducing possible local and systemic reactions. Metal ion (cobalt or chromium) levels in the blood may reach very high concentrations during this disease and are used for its diagnosis.

MicroPort. A type of vascular access port.

Miller-Abbott tube.  A type of intestinal drainage and decompression tube with a weighted mercury  bag and two channels.

Milwaukee brace. An external brace used to stabilize or correct spine deformities in skeletally immature patients. Also known as a CTLSO brace, a Milwaukee brace is most commonly used to treat scoliosis and kyphosis as opposed to a TLSO brace which is most commonly used to treat vertebral injuries. A Milwaukee brace is a full torso brace that extends from the base of the skull to the pelvis, while a TLSO brace is more limited to the thoracolumbar region.

Minnesota tube.  A complex, multiple balloon tube similar to a Sengstaken-Blakemore tube.  It is used to treat esophageal or stomach varices.

Mirror imaging artifact.  A type of ultrasound artifact that may be created adjacent  to a highly reflective acoustic interface.

MILS. Minimally invasive lumbar surgery, minimally invasive lumbar stabilization.

MIS. In regard to orthopedics, minimally invasive surgery.

MISS. In regard to orthopedics, minimally invasive spine surgery, minimally invasive spine stabilization.

MIS TLIF. Minimally invasive surgery (MIS) transforaminal lumbar interbody fusion (TLIF).

MITA. Medical Imaging and Technology Alliance. A division of NEMA, MITA represents medical imaging equipment manufacturers, innovators, and product developers.

MMF. Mandibulomaxillary fixation, wiring the jaw shut to obtain occusal reduction as part of the treatment for a mandibular fracture.

Mobin-Udin umbrella.  A type of inferior vena cava filter used to prevent clot propagation to the lungs.

Modularity. The ability to add implant components, such as stems, augments, and wedges, to enable the surgeon to make a custom prosthesis intraoperatively.

modular spine-fixation system.  A spine fixation system using pedicle screws, distraction hooks, intermediate screws, and a universal rod.

Moe plate.  A metallic bone plate used for fixation of an intertrochanteric femur fracture.

MOMHR. Metal-on-metal hip resurfacing implant.

MORA. Mandibular orthopedic repositioning appliance, an appliance for restoring a collapsed temporomandibular (TM) joint.

MOW. Medial opening [tibial] wedge osteotomy.

Morscher plate.  An anterior cervical spine fixation system using a plate and a hollow screw.

MRI port.  A type of vascular access port.

mules (also known as “body packers”).  People who smuggle drugs by ingesting or inserting into their rectum or vagina drug filled-packets. The packing material is typically a condom or balloon,  and the packets vary in their relative radiopacity.

Multiload-250.—a type of intrauterine contraceptive device.

MVR.  Mitral valve replacement.


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Author contact information

Tim Hunter

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