Treatment of Tuberculosis of the Knee.

A FEW general observations are pertinent before considering the treatment of tuberculosis of the knee in its different clinical manifestations. 1. Tuberculosis of a joint implies that blood-stream dissemination following primary infection has occurred. Full investigation of the patient with regard to the lungs, the urine and other bones and joints is therefore essential. 2. Monarticular rheumatoid arthritis in adults or children is by no means uncommon and may exist in a child who already has a positive Mantoux, so that the diagnosis of an early case without bone destruction may require considerable investigation. 3. The range of clinical material and the incidence vary much in different parts of the world. In England today tuberculosis of the knee is rarely seen, is frequently seen early and has become relatively much less common in children. In many countries where there are still numbers of sputum-positive patients and a lower standard of living and medical care, and where communications are difficult, many patients and more with advanced disease are seen. 4. The results of some of our diagnostic tests vary with the race of the patient. This is particularly true of the sedimentation rate. Natives of Britain with active skeletal tuberculosis commonly have a sedimentation rate which is, if raised at all, between 15 and 35 mm. in the first hour. Much higher figures than this in a spinal lesion raise a strong suspicion that the disease is staphylococcal and not tuberculous; similar high figures in a patient with a single joint affected would suggest rheumatoid disease. However when we meet patients in this country from Asia, Africa or the West Indies with a closed single tuberculous lesion, they commonly have a sedimentation rate in the higher range when first seen, e.g., 50-70 mm. in the first hour. 5. Radiographically it is most important to take strictly comparable views of the sound knee, if possible on the same film, so as to aid the detection of minor degrees of osteoporosis and changes in texture of the cancellous bone. Before the era of antibiotics it was taught that spontaneous or deliberate arthrodesis was the only safe end-result in tuberculosis of the knee. Usually despite prolonged rest varying degrees of bone destruction occurred, with fibrous adhesions and restriction of movement. Such joints were always at risk of re-activation by minor degrees of trauma. The natural resistance of the human body now aided by antibiotics may ultimately produce quiescence of the lesion. We have then created a desert for the mycobacteria inhabiting the lesion, but he would be bold who asserted that nowhere in the areas of "healed" and probably fibrotic tissue were there no lurking bacteria or their coccal forms. Blood and effusion provide the ideal watering of the desert, and it is for this reason that the tearing of an adhesion in a joint with limited movement can so easily re-activate tuberculosis. But with the new drugs, with or without operation, we can commonly hold the situation if a diagnosis is made early enough, and this gloomy outlook is no longer with us.