In current forms of treatment, the evidence derived from clinical studies rigid (randomized clinical trials, double-blind, placebo-controlled, well-designed) originate Class I Evidence. This evidence is used to support strong recommendations, called practice standards, indicating a high degree of clinical certainty. Well-designed clinical studies such as case control or cohort studies, show the evidence Class II. This evidence is used to support recommendations called Practical Guides lines, reflecting a moderate degree of clinical certainty. Other sources of information, including observational studies (case series or expert opinion, for example) where the study's findings are questionable truths generate Evidence Class III. Class III evidence supports practice reviews, reflecting a clinical certainty is not clear. The general term for all these recommendations is to Practice Parameter. Because there are few practical standards, the recommendations that are most frequently used are the lines Practice Guidelines.
These notes are derived from studies that provide class II evidence because it is called Guide Lines Measurements in Imaging Studies of Cervical Spine.
Measurements that are recorded are not always real, but are used to illustrate the techniques and results. The photographs were manipulated in Adobe Photoshop CS, CorelDRAW 11 and OsiriX (open program for measurements of medical images). They process information in a computer MacBook Pro.
Jorge Luis Olivares Camacho
Orthopaedic Surgeon