pain fibers: Axons of pain sensitive nerve cells.

 

pain generator: Abnormal tissue or joint responsible for the pain that affects a larger area.

 

parasympathetic nerves: Part of the autonomic nervous system.

 

pars interarticularis: The part of a vertebra between the lamina and the superior facet; this may be abnormal in the condition called spondylolysis.

 

PCA (patient controlled analgesia): Method of pain treatment after surgery that allows the patient to self-administer pain medication under a controlled regimen.

 

pedicle: Portion of the vertebra that connects the lamina (posterior part of the vertebra) to the body anteriorly and helps forms the walls of the spinal canal. 

 

pedicle screws: Fixation screws that are placed through the pedicle of the vertebra.

 

peptides: Small proteins.

 

percutaneous: Procedure done through a puncture in the skin, typically by a needle or through a very narrow cannula. 

 

perineum: The skin and tissues between the legs. 

 

periosteum: The lining of the bone. It has sensation and it helps control the shape and growth of bone.

 

peripheral nerves: The nerves after the departure from the spinal canal, proceeding out to their end point in the skin and muscles. 

 

periphery: The parts of the body furthest away from the spinal cord and brain. 

 

peritoneum: The internal lining of the abdominal cavity.

 

peroneal nerve: A nerve that commences just above the knee, passes along the lateral aspect of the lower leg and helps activate muscles that lift the foot. 

 

phased-array coils: Equipment used in MRI scanning to improve the signal to noise or image quality of the MRI scan.

 

Pilates: An exercise based treatment for the spine and for overall body maintenance. 

 

pinched nerve: Entrapment or mechanical pressure affecting a nerve.

 

piriformis muscle: A muscle that runs from the sacrum to the top of the femur, that can cause buttock pain and entrap the sciatic nerve. 

 

placebo: A pill that carries no actual medicine.

 

placebo effect: Improvement of a condition experienced by a patient who believes a treatment has been administered even if the treatment was not actually done.

 

plantarflexion:  Bending the ankle to move the toes downwards  

 

plasticity: It is adaptation of the nervous system to new connection patterns. 

 

pleural lining: A thin lining of the lungs.

 

pneumonia: An infection of the lungs.

 

Point of Service (POS) Insurance: A plan in which the patient can enter either an HMO plan, a PPO (a preferred provider) or a non-contracted plan depending on how they commenced care for any given condition they experience. 

 

point based treatments: Acupuncture or acupressure for a nonsurgical treatment of back pain.

 

polymers: Complex molecules with many individual parts, typically such as plastics or other complex absorbable molecules used in surgical treatment and implants.

 

posterior: Towards the back of.

 

posterior longitudinal ligament: A ligament behind the vertebral bodies and anterior to the spinal dura and spinal cord.

 

posterior-anterior X-rays: Images obtained with the X-ray source in front of the spine and the film behind the spine. 

 

posterolateral fusion: A lumbar fusion done from a posterior approach and incorporating the transverse processes of the lumbar vertebrae.

 

PPO (preferred provider organization): Type of health insurance in which patients may choose from a physician from a list of providers who have agreed to offer care at a discount. 

 

prognosis: Expectation of the outcome of treatment.

 

preemptive anesthesia: The administration of pain medication before surgery in an attempt to prevent the pain from becoming intense as the surgery progresses. 

 

prophylactic: Something administered to prevent the development of a problem such as antibiotics given to prevent the possibility of an infection. 

 

prospective cooperative study: Test to evaluate the efficacy of a treatment, typically done by determining the clinical plan before any of the patients commence treatment and involving many different hospitals. 

 

provocative discogram: A test to evaluate whether an intervertebral disc is a pain generator.  Fluid is injected into the disc to learn whether the resulting pain is similar to the patient's usual pain.

 

pseudoarthrosis: Literally "false joint" - a painful contact between two bones that develops at the site of a failed fusion.

 

pus: A reactive material produced in an infection by the accumulation of the body's white cells attempting to digest bacteria.