Spinal Glossary: P

  • PA: Physician's assistant.
  • PDR: Physicians' Desk Reference. Guide to drugs available in U.S.
  • pedicle: Projection of bone from the back of the vertebra that helps form the ring around the spinal canal.
  • percutaneous: Passage through skin by needle or other object.
  • percutaneous lumbar discectomy (PLD): The removal of bulging disc material through a large bore needle inserted into the disc space. The disc material is removed using cutting, sucking or laser appliances. Also known as percutaneous microdiscectomy.
  • percutaneous nucleotomy: The removal of disc material through a large bore needle.
  • PMMA (polymethyl methacrylate): A synthetic polymer of methyl methacrylate. This transparent thermoplastic was developed in 1928 and is used in a number of different applications, including as a glass substitute for daylight redirection, artistic and aesthetic purposes and also in medical applications.
  • posterior: A term that is defined as nearer to the end or further back. Derived from the Latin "post," meaning "after," posterior is often used in an anatomical setting to describe things that are situated toward the rear end or toward the back plane of the body.
  • posterior lumbar interbody fusion (PLIF): A spinal surgical procedure in which a bone graft and/or spinal implant is inserted into the disc space in order to achieve spinal fusion. This fusion provides stabilization, thereby potentially ending painful symptoms resulting from a spinal condition.
  • PRN (pro re nata): In Latin, means "in the circumstances." As used in a medical field, it means "as needed," as in reference to the dosage of a prescribed medication.
  • pseudarthrosis: (variation: pseudoarthrosis) Derived from the Greek "pseud," meaning "false," and "arthrosis," meaning "joint." It describes a condition in which a bone has movement at the location of a fracture due to the inadequate healing of the fracture.
  • PT (Physical Therapist): A trained medical professional who treats people of all ages with medical problems, conditions, illnesses or injuries that limit their capacity for movement and ability to perform activities necessary in their daily lives.
  • PVA (percutaneous vertebral augmentation): Percutaneous vertebral augmentation. A procedure that helps restabilize collapsed vertebral bodies by injection of material into the collapsed area. Includes vertebroplasty and kyphoplasty.
  • Pinched Nerve: A colloquial term for nerve compression, often associated with degenerative conditions such as spinal arthritis and degenerative disc disease. This condition can occur at any level of the spine but is most common in the lumbar (lower back) and cervical (neck) regions. A pinched nerve produces localized pain, radiating pain, tingling, numbness and/or muscle weakness.
  • Prolapsed Disc: Occurs when the soft jelly-like material that comprises the center of a disc pushes through the fibrous shell and into the spinal column. Also known as a herniated or ruptured disc.
  • physical therapy: The medical field focused on developing, maintaining and restoring maximum movement and functional ability for an individual whose quality of life and abilities in these areas are threatened by age, injury, disease or environment.
  • pia mater: The innermost layer of the meninges, which is the system of membranes that surrounds the brain and spinal cord. As a group, the meninges protect the central nervous system by containing cerebrospinal fluid, which cushions the spine.
  • posterolateral fusion: A form of spinal fusion surgery performed from the back, this procedure is designed to increase spinal stability in patients with degenerative spine conditions.
  • posture: In a general sense, the habitually assumed or intentionally assumed position of the human body.
  • posterior longitudinal ligament: A ligament situated in the spinal canal that begins in the axis and culminates in the sacrum. This ligament runs behind the spinal cord and limits flexion in the spine.
  • pars fracture: Also known as spondylolysis, a pars fracture is an injury to the pars interarticularis in the posterior section of the spinal column. This stress fracture is extremely common in young athletes and is commonly caused by overexertion and repetitive motions.
  • pars fracture surgery: A surgical procedure used to address a pars fracture or spondylolysis and alleviate chronic pain.
  • paralysis: Loss of muscle function due to an interruption of sensory and motor signals between the brain and the spinal cord. Paralysis is usually caused by a stroke or nerve damage of some kind.
  • pregnancy and back pain: Back pain can be common in pregnant women due to the increased amount of weight that is putting pressure on the lumbar spine (lower back). Many pregnant women have also reported feeling pain in their posterior pelvis area, deep in the buttocks and in the backs of the thighs.
  • physical exam: A means for evaluating exterior abnormalities and other symptoms that may indicate whether a patient has a certain medical condition.