Classification of elbow stiffness.

Stiffness is a clinical disorder that affects the patient's function of the entire upper limb. Many classifications systems have been developed for elbow stiffness based on the plane of motion, severity, aetiology, prognosis or anatomical location. A new classification, the Stiffness types and Influencing Factors Classification System, is proposed as a treatment algorithm to guide the surgical treatment and the preferred operative approach (open or arthroscopic).