Stenosing tenosynovitis

This is a chronic benign condition, in which a patient's tendons no longer run smoothly in their sheaths. His symptoms depend upon which tendon is involved. This disease appears to be less common in the developing world than it is elsewhere.

If he complains of pain (and sometimes an abnormal prominence) over his radial styloid, which may be worse on extending and/or abducting his thumb, its abductor and short extensor tendons are constricted in their sheaths, as they pass over the groove in the end of his radius (de Quervain's disease). They are tender, and you can usually feel a thickening in the tendon sheath. Flexion and adduction of his thumb causes pain over his radial styloid.

If he complains that, when he flexes one of his digits it locks, (''trigger finger' or thumb), so that he cannot extend it again, until he does so passively and forcefully, his flexor tendons are involved. His powerful flexors are able to pull the swollen part of the tendon proximal to the constriction, but his weaker extensors are unable to extend his finger again unaided.

STENOSING TENOSYNOVITIS If the abductor and short extensor tendons of a patient's thumb are involved and the disease is early, inject the lesion with 0.5 ml of lignocaine mixed with 0.5 ml of a suspension of hydrocortisone using the most careful sterile precautions. Place the point of a very fine needle into the palpable swelling, just distal to his radial styloid, and inject between the tendon sheath, and the bone of the groove of his styloid. If you are successful, you will see a wheal appearing on the proximal side of the tendon sheath.

If injection is not successful (50% of cases), make a small transverse skin incision over his radial styloid. Use a fine tenotomy knife to make a longitudinal incision in the sheath to release the tendon. Leave the sheath open, suture his skin only, and start active movements immediately. The result will be good.

CAUTION ! (1) Avoid the cutaneous branch of his radial nerve, so look for it immediately you incise the skin. (2) Don't try to pare down the tendon. (3) There may be several slips to the tendon, and thus several compartments in the sheath; make sure each is free.

If the flexor tendon of his thumb is inolved at his MP joint (''trigger thumb'), first try steroid injection, as above. If this is not successful, and you cannot refer him, operate. Give him an intravenous forearm block (A 6.19), or a median and ulnar nerve block (A 6.20). Apply a tourniquet; you will need skin hooks and very small retractors. Make a 1 cm incision in the midline of his thumb, on its volar aspect, in the crease of his MP joint, and release the stenosis as above.

CAUTION ! The danger with this operation is that you may cut his digital nerves, so you must know where they are. Review the anatomy before you operate.

If the flexor tendons of his fingers are involved (commonly his ring or middle finger, occasionally his little finger), refer him. If this is impossible, make a 1 cm transverse incision on the palmar surface of his hand, half way between his distal palmar crease and the flexion crease of his finger. Insert retractors and carefully deepen the incision. Take care to find his digital nerves, so that you don't cut them.

When you find the narrowed tendon sheath cut it longitudinally with a No. 15 blade. Insert a small pair of pointed scissors, and run them distally to cut the stenosed sheath. As soon as you have done this, you can flex his finger.

Fig. 27-14 TWO WRIST DISEASES. A, when a patient has stenosing tenosynovitis of the extensor tendons of his thumb, make a transverse incision in the skin of his wrist. B, divide the constriction in his tendon sheath longitudinally with a No. 15 scalpel blade. C, avoid operating on a ganglion if you can. D, if you have to operate, remove the ganglion, and a little of the adjacent tendon sheath, which will reduce the probability of its recurring.