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Injury,

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Tardy palsy of the radial nerve from a Monteggia fracture Roger Austin The Leicester Royal Infirmary,

Leicester

Summary

A case of tardy palsy of the radial nerve, which developed 65 years after a Monteggia fracture that remained unreduced, is described. The weakness recovered sufficiently well for a tendon transference to be unnecessary, partly because the patient was semiretired. This condition is rare but comparison with the only two similar reported cases of tardy radial and posterior interosseous nerve palsy associated with long-standing dislocation of the superior radio-ulnar joint suggests that the prognosis for recovery of such a palsy following excision of the radial head is better than might be expected.

A RETIRED labourer, 72 years of age, came to Hinckley Hospital in January, 1974, complaining of inability to extend the fingers and thumb of the left hand and of weakness of dorsiflexion of the left wrist. He also complained of paraesthesia affecting the dorsum of the first web space of the hand. The onset of these symptoms had been spontaneous, 1 month previously. The patient remembered that he had sustained an injury to the left elbow when he was 7 years of age but could not remember the details of either the injury or its treatment. The elbow had not caused noteworthy trouble during his working life and he was in fact working part-time. The power of the extensors of the fingers and thumb of the left hand was reduced to grade 1, the dorsiflexors of the wrist to grade 3. There was no loss of awareness of touch or pin prick on the hand or forearm. The left elbow had a full range of active flexion, extension and pronation; there was no active supination present but passive supination was full. Considerable crepitus was

felt over the joint and anterior dislocation of the head of the radius was apparent. The power of the elbow’s flexor and extensor muscles was normal, as was the power of the flexors of the wrist and fingers. Radiographs of the left elbow revealed an old, unreduced Monteggia fracture with anterior bowing of the ulna and anterior dislocation of the radius. The radial head was deformed (Fig. 1). Radiographs of the left shoulder were normal. Radiographs of the neck showed spondylosis with the discs’ spaces narrowed and anterior osteophytes at the levels of C5/6 and C6/7. The radial nerve and its branches were explored through an anterior incision, the belly of brachioradialis being retracted laterally. The radial nerve was encased in a mass of fibrous tissue which enveloped the posterior interosseous nerve also and lay anterior and superior to the dislocated radial head. The nerves were dissected out of this mass and the posterior interosseous nerve was found to be particularly thin and pale. The radial head was exposed by incising the fibrous mass lateral to the freed nerves and it was found to be eccentric to the radial neck, as suggested by the radiographs (Fig. 1). Pronation and supination of the forearm caused the radial head to press on the radial and posterior interosseous nerves with a cam-like action. The radial head was excised. Little hope was held for the functional recovery of the posterior interosseous in view of both the length of time that it had been subjected to trauma and the appearance of the nerve at operation. However, immediately after operation the paraesthesia in the first web space was

Austin : Tardy Palsy

Fig. 1. Radiograph

203

of the left elbow showing an old unreduced Monteggia fracture and deformity of the

radial head. relieved. One month later an increase in power was noted in the extensor pollicis longus and the fingers’ extensors, and this slowly improved over the next 9 months. At that time the strength of extensor pollicis longus was grade 4 and of the fingers’ extensors, grade 3. The dorsiflexors of the wrist had grade 4 strength. This weakness was not interfering with his part-time employment and he was discharged.

DISCUSSION Non-traumatic, progressive, posterior interosseous nerve palsy has been ascribed to a variety of causes in the elbow region. The nerve may be compressed by a lipoma (Capener, 1966), a ganglion (Bowen and Stone, 1966), a fibroma or dense fibrous tissue. Sometimes no obvious cause for compression is found although the nerve may be adherent and oedematous (Sharrard, 1966). Tardy radial nerve palsy has been described in association with a long-standing anterior dislocation of the superior radio-ulnarjoint by Adams and Rizzoli (1959) and a tardy palsy of the posterior interosseous nerve associated with an old unreduced anterior Monteggia fracture has been reported by Lichter and Jacobsen (1975). These three cases exemplify a rare cause of tardy palsy of the radial or posterior interosseous nerves. Certain features are common and seem particularly pertinent. Each patient sustained an injury in childhood, resulting in uncorrected

anterior dislocation of the superior radio-ulnar joint. The interval between the original childhood injury and the onset of symptoms was, in each case, lengthy; 47, 39 and 65 years. At the time of presentation the dislocated radial head was deformed and eccentric, with the radial and/or the posterior interosseous nerves stretched over the radial head. In Lichter and Jacobsen’s case, and in the present one, extensive perineural fibrosis was present and pronation and supination were seen to increase the pressure by the eccentric radial head on the nerve. In each patient resection of the radial head was followed by satisfactory recovery of the nerve so that it was not necessary to transfer any tendons. The time between the original injury and the onset of the palsy is interesting and perhaps unexpected, because each patient was a manual worker. A possible explanation is that the damage to the radial and posterior interosseous nerves may have been mitigated by the movement of the nerves that supination occurs during pronation and (Strachan and Ellis, 1971).

REFERENCES ADAMSJ. R. and RIZZOLI H. V. (1959) Tardy radial and ulnar nerve palsy. J. Neurosurg. 16, 342. BOWENT. L. and STONEK. H. (1966) Posterior interosseous nerve paralysis caused by ganglion at the elbow. J. Bone Joint Surg. 48B, 114.

injury: the British Journal of Accident Surgery Vol. ~/NO. 3

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CAPENERN. (1966) The vulnerability of the posterior interosseous nerve of the forearm. J. Bone Joint Surg. 48B, 770.

LIGHTERR. L. and JACOBSENT. (1975) Tardy palsy of the posterior interosseous nerve with a Monteggia fracture. J. Bone Joint Surg. 57A, 124. Requests/or

reprints should

be addressed lo:

Mr R. Austin, Consultant

SHARRARDW. J. W. (1966) Posterior interosseous neuritis. J. Bone Joint Surg. 48B, 771. STRACHANJ. C. H. and ELLIS B. W. (1971) Vulnerability of the posterior interosseous nerve during radial head resection. J. Bone Joint Surg. 53B, 320.

Orthopaedic

Surgeon, The L&ester

Royal Infirmary,

Leicester, LEl 5WW.

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Tardy palsy of the radial nerve from a Monteggia fracture.

A case of tardy palsy of the radial nerve, which developed 65 years after a Monteggia fracture that remained unreduced, is described. The weakness rec...
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