In certain cases, _genu valgum_ or abduction of the leg is present along with a slight degree of flexion. The valgus attitude is associated with slight lateral displacement of the patella, with prominence and apparent enlargement of the medial condyle, with depression of the pelvis on the diseased side and apparent lengthening of the limb.
#Treatment of Tuberculous Disease of the Knee.#--Conservative measures are always indicated in the first instance, and are persevered with so long as there is a prospect of obtaining a movable joint.
_Conservative Treatment._--If the joint is sensitive and tends to be flexed, the patient is confined to bed, the limb is secured to a posterior splint, and extension with weight and pulley persevered with until these symptoms have disappeared; during this time, from three to six weeks, methods of inducing hyperæmia and other anti-tuberculous procedures are employed. If it is proposed to inject iodoform or other drug, the needle is inserted into the interval between the bones on the medial side of the ligamentum patellæ or into the upper pouch when this is distended with fluid.
If there is no pain or tendency to flexion, or when these have been overcome, the limb is put up in a Thomas' splint (Fig. 125) and the patient allowed to go about. The splint is worn for a period varying from six to twelve months; before being discarded it may be left off at night; it is ultimately replaced by a bandage.
[Illustration: FIG. 125.--Thomas' Knee Splint applied. Note extension strapping applied to affected leg, and patten under sound foot.]
The indications for _operative treatment_ are: (1) marked symptoms of destruction of the articular cartilages; (2) a deformed attitude incapable of being rectified without operation; (3) a condition of the general health which requires that the disease should be got rid of as speedily as possible; (4) progress or persistence of the disease in spite of conservative treatment. When there is no prospect of recovery with a movable joint it is a waste of time and a possible source of danger to persevere with conservative measures. Operation permits of the disease being eradicated and the restoration of a useful limb within a reasonable time, averaging from three to six months.