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Dr. Eliseo Mora Sánchez
2023-05-10 |
Osteonecrosis of the Knee (ONR) was first described by Ahlback in 1968.
Although this disease primarily affects the medial condyle, it can also be seen on the lateral condyle and tibial pads.
Primary or idiopathic osteonecrosis generally occurs after the age of 60, is three times more common in women than in men, and affects the medial femoral condyle.
Secondary Osteonecrosis affects people under the age of 60, is seen in both knees or multiple joints, and is closely related to steroid use.
This disease generally appears in patients older than 60 years, who debut with acute pain located in the medial region of the knee and normal radiographs.
The pain is of moderate intensity although it can increase at night or increase with physical activity. The patient usually remembers the exact moment of the appearance of his symptoms which are not related to a specific precipitating factor.
Although the true cause of ONR remains unknown. Two possible theories are put forward:
Vascular theory: this theory is based on a condition of the microcirculation of the subchondral bone of unknown cause which produces edema, which consequently increases the pressure in the bone marrow with reduced circulation, which causes ischemia. If the bone structure collapses, the classic radiographic appearance is observed; if revascularization occurs, the lesion heals and the symptoms disappear.
Trauma theory: is based on the fact that this condition is more common in women over 60 years of age, who generally present osteoporosis, which in turn predisposes subchondral bone weakness, which It can easily present microfractures due to increased compression forces on the knee. At this time, edema occurs in the bone marrow, increasing the pressure, which causes ischemia.
Source: Álvarez López, Alejandro, García Lorenzo, Yenima, Puentes Álvarez, Antonio, & García Lorenzo, Maruldis. (2010). Osteonecrosis of the knee: current approach. Camagüey Medical Archive Magazine, 14(5) Retrieved on May 10, 2023, from http://scielo.sld.cu/scielo.php?script=sci_arttext&pid=S1025-02552010000500017&lng=es&tlng=es.
