Osteochondral lesions

MEDICAL INFORMATION

Osteochondral lesions comprise osteochondritis dissecans and osteochondral fractures. These lesions affect circumscribed areas of bone and cartilage on any articular surface, causing pain, stiffness, and inflammation. They originate from vascular, traumatic, or microtraumatic causes and may be accompanied by bone marrow edema in the surrounding areas. The most frequent involvement occurs in the femoral condyles and the internal talar dome, although it can also affect the shoulder, elbow, hand, and hip. Diagnosis via MRI allows for exact and precise localization, as well as the assessment of size and extent, and enables follow-up monitoring. Ultrasound helps assess the depth of the focal point when using generators such as piezoelectric devices, which feature a smaller focal zone.

APPLICATION TECHNIQUE

The affected area will be studied via MRI to determine the three-dimensional location of the lesion, assess the focal point's area of incidence, and establish whether the osteochondral involvement is stable. In the most common case involving the talar dome of the ankle, the anterior and middle zones of the internal talar dome are typically affected. Therefore, the most common entry path for the shock wave will be through the internal region inferior to the medial malleolus and the superior region of the talar dome to reach the osteochondral lesion, as the articular surface is not exposed during extension.

In cases involving the knee condyles, the medial region of the femoral condyle is most frequently affected. We will flex the knee to ensure an adequate window for the condyle, as it is covered by the tibia during extension. In the case of the femoral head, the patient is usually placed in a supine position to access the focal point from the ventral region of the joint and reach the affected area of the femoral head. A similar approach is used for the humerus, elbow, or hand, accessing anteriorly, laterally, or posteriorly based on the MRI assessment. The therapist should be comfortably seated to perform a minimal scanning area over the osteochondral lesion, according to the area being treated.

SOURCE: Dr. Juan Miguel Morillas Martínez. (SETOC Quick Reference Guide for Extracorporeal Shock Wave Therapy Medical Protocols).