Pedicle Screws In The Cervical Spine

Atlantoaxial instability (AAI) is characterized by excessive movement at the junction between the atlas (C1) and axis (C2) due to either a bony or ligamentous abnormality. Neurologic symptoms occur when the spinal cord is involved. The causes of AAI are varied. AAI sometimes results from trauma. Other cases occur secondary to an upper respiratory infection or infection following head and neck surgery. Another cause is rheumatoid arthritis (RA), with its predilection for the upper cervical spine. In addition, congenital anomalies, syndromes, or metabolic diseases can increase the risk of AAI.
Synonyms and related keywords: AAI, atlantoaxial subluxation, AAS, rotary dislocation, rotational subluxation, spontaneous hyperemic dislocation, atlantoaxial rotary subluxation
Banit, Murrey & Darden 2005

Descriptions of myofascial pain date back to the mid 1800s when Froriep described muskelschwiele or muscle calluses. He described these calluses as tender areas in muscle that felt like a cord or band associated with rheumatic complaints. In the early 1900s, Gowers first used the term fibrositis to describe muscular rheumatism associated with local tenderness and regions of palpable hardness. In 1938, Kellgren described areas of referred pain associated with tender points in muscle. In the 1940s, Janet Travell, MD, began writing about myofascial trigger points. Her text, written in conjunction with David Simons, MD, continues to be viewed as the foundational literature on the subject of myofascial pain.
Synonyms and related keywords: myalgia, myofasciitis, interstitial myofibrositis, fibrositis, nonarticular rheumatism affecting the cervical spine, tension myalgia
Beth B Froese, MD 2006

Cervical strain is one of the most common musculoskeletal problems encountered by generalists and neuromusculoskeletal specialists in the clinic.
One cause of cervical strain is termed cervical acceleration-deceleration injury. This is frequently called whiplash injury.
Whiplash is the most common sequela of nonfatal car injuries. Whiplash is one of the most poorly understood disorders of the spine, and the severity of the trauma often is not correlated with the seriousness of the clinical problems (Riley, 1995). A history of neck injury is a significant risk factor for chronic neck pain (Croft, 2001). Pretorque of the head and neck increases facet capsular strains, supporting its role in the whiplash mechanism (Winkelstein, 2000).
The Quebec Taskforce on Whiplash-Associated Disorders has suggested the following system for classifying the severity of cervical sprains (Spitzer, 1995): 0 = no neck pain complaints, no physical signs; 1 = neck pain complaints, only stiffness or tenderness, no other physical signs; 2 = neck complaints and musculoskeletal signs (decreased range of motion [ROM] and point tenderness); 3 = neck complaints and neurologic signs (weakness, sensory and reflex changes); 4 = neck complaints with fracture and/or dislocation.
Synonyms and related keywords: C-spine sprain, C-spine strain, acceleration/deceleration injury, acceleration-deceleration injury, cervical myofascial pain, cervical soft tissue pain syndrome, cervical sprain, cervicobrachial strain, chronic cervical sprain, chronic cervical strain, chronic neck sprain, chronic neck strain, extension-flexion injury, extension/flexion injury, flexion/-extension injury, flexion/extension injury, hyperflexion-hyperextension injury, hyperflexion/hyperextension injury, neck/shoulder girdle soft tissue injury, neck sprain, neck strain, regional soft tissue pain syndrome, WAD, whiplash-associated disorders, whiplash syndrome
Hunter & Freeman 2006

Minimum detectable and minimal clinically important changes for pain in patients with nonspecific neck pain Francisco M Kovacs , Victor Abraira , Ana Royuela , Josep Corcoll , Luis Alegre , Miquel Tomas , Maria Antonia Mir , Alejandra Cano , Alfonso Muriel , Javier Zamora , Maria Teresa Gil del Real , Mario Gestoso and Nicole Mufraggi BMC Musculoskeletal Disorders 2008, 9:43 Abstract & link to free full text
Conclusions In general, improvements equal to or less than 1.5 PI-NRS points could be seen as irrelevant. Above that value, the cutoff point for clinical relevance depends on the methods used to estimate minimal clinically important changes (MCIC) and on the patient's baseline severity of pain. Minimal detectable change (MDC) and MCIC values in neck pain patients are similar to those for low back pain and other painful conditions.

When the concept of whiplash was first introduced by Harold Crowe in 1928 at a conference, and when it first appeared in a medical publication in 1945, it was not based on scientific evidence. That is, like many great stories, the whiplash theme sprang mainly from mythology, where many explanations had to be created to fill in the gaps in our understanding. Since those early days, and mainly in the last ten years, more research has been carried out to unravel these myths than had been performed to define chronic whiplash in the first place. This limited review considers a few of the aforementioned myths of whiplash, and how scientific efforts have enlightened us on these matters
Surg J R Coll Surg Edinb Irel., 1 April 2003, 99-103

Os odontoideum describes a condition in which the dens is separated from the axis body. Os odontoideum initially was thought to be a congenital failure of fusion of the dens to the remainder of the axis. As such, it usually is grouped with other craniocervical junction abnormalities, such as dental aplasia and hypoplasia. These lesions are clinically important because the mobile or insufficient dens renders the transverse atlantal ligament (TAL) incompetent. Without a functional dens-TAL complex, translation of the atlas on the axis is not effectively restrained. With increased motion, upper cervical cord or vertebral artery impingement may occur.
Author: Eeric Truumees, MD 2005