[Width of the normal tendon sheath in the 2d to 5th fingers in oblique exposures]

Oblique views of the fingers, using a low kilovolt technique, show a portion of the tendon sheaths which can be regarded as representative of the entire sheath. Because of the varying obliquity of each finger, this proportion differs in the fingers. With increasing age the projected portion of the sheath becomes smaller because it is covered by increasing bone formation in the insertion of the tendon sheath. Normal values have been obtained for adults according to their decades; from these, quite minor degrees of tendon sheath thickening can be determined. In camptodactyly of the fifth finger, which is not uncommon, the tendon sheath may be widened in the absence of a tenosynovitis.