The main function of the PT control knee orthosis is to stabilise and correct the patella by means of the individually adjustable guide frame that slides with the patella. Under this there is an air cushion which ensures maximum comfort. Areas of application Conservative or surgical management of patellar dislocation combined with slight to moderate instability: if the knee cap is dislocated, or, as it is also called, pops out, this is usually the result of an accident. However, rheumatoid arthritis can also trigger this condition. The system of capsules and ligaments is then repeatedly subject to such stresses that the knee cap no longer remains in the guide and pops out. Lateral malalignment combined with slight to moderate instability: the term malalignment describes an incorrect movement of the knee cap; usually the patella slips sideways.