The patella is located in the front of the knee joint, in the groove formed by the femur and tibia bones, and is able to slide along the length of this groove. As a result of trauma, lateral impacts or sliding outside the groove during an abnormal movement or sudden twist or turn, the patella can become partially displaced, resulting in subluxation, or fully displaced, causing dislocation. Some factors such as patella femoral dysplasia, patella alta or trauma can predispose to subluxation or dislocation, which can occur proximally or mediolaterally, the latter being the most common. By relaxing the quadriceps with the leg in extension, it is possible to achieve reduction with relative ease.
Patellar Dislocation Symptoms
Subluxations cause pain and functional disability, with the pain reduced in cases of recurrent injury, although these episodes can damage the knee joint. The same goes for patellar dislocations, in which the pain is greater and incapacitating, and can be associated with damage to the cartilage or other tissue in the joint itself. The presence of oedema may be evident, in which case the patient should remain at rest with the leg elevated.
Patellar Dislocation Treatment
The immediate application of cold compresses, ice packs or knee braces with internal pockets designed for such a purpose can provide immediate relief by reducing inflammation. Subsequent use of an open kneecap brace after reducing the dislocation enables the patella to be centred and stabilised. Rehabilitation techniques to strengthen the knee muscles, together with the use of a knee brace, will help the patient to recover quickly, and it is advisable to continue using braces during sport as a method of prevention, especially in recurrent dislocations.