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Radial nerve laceration two years after a stab wound to the distal humerus: A case report
RADIAL NERVE LACERATION TWO YEARS AFTER A STAB WOUND TO THE DISTAL HUMERUS: A CASE REPORT S. MALOON and M. SINGER From the Hand Unit, Groote Schuur Hospital, Cape Town, South Africa A patient is described who was stabbed in the upper arm and two years later developed a radial nerve palsy. X-rays showed that the tip of the knife had broken off in the arm. At operation this bit of blade was loose and had completely divided the radial nerve. Journal of Hand Surgery (British Volume, 1990) 15B: 494-495 Case history
A 33-year-old truck driver presented with a one-week history of inability to extend his wrist or the fingers of his right hand. He denied injury, but admitted that he had been drinking on the evening before the onset of symptoms. On examination, he was found to have a complete motor and sensory deficit in the distribution of his right radial nerve below the elbow. On the lateral aspect of his distal humerus was an old well-healed scar overlying a firm mass. On direct questioning, he explained that he had been stabbed two years previously but had not sought medical treatment for the small wound which had healed rapidly. X-ray examination of the distal humerus (Fig. 1) revealed 8 ems. of a hunting-knife blade lying anterior to the humerus and embedded in new bone, confirming the length of time that the foreign body had been present. The blade appeared loose and the new bone around the tip of the blade was fractured. The differential diagnosis of the nerve injury was “Saturday night palsy” or delayed injury by the metallic
Fig. 1
494
(a) A.P. and (b) Lateral
radiographs
showing
the broken-off
foreign body. As we were unsure of the cause, the patient was initially treated conservatively with a lively extensor splint. After ten weeks there had been no improvement, so the nerve was explored. At operation, the blade was found to be quite loose and was removed with ease. The radial nerve was identified at the level of the elbow and traced proximally into dense scar tissue, where it was found to be completely divided. When the scarred nerve ends were resected, a 6 cm. defect was evident. Direct repair was not possible and, in view of the dense scar tissue bed, no graft was attempted. Two weeks later, he underwent the following tendon transfers: 1) Pronator teres to extensor carpi radialis brevis 2) flexor carpi ulnaris to extensor digitorium communis 3) palmaris longus to extensor pollicis longus. The operation was successful and within two months the patient was back at work. Discussion
In view of the length of time between the stab injury and the onset of the radial nerve palsy, we feel that our patient
end of the blade and its relationship
to the humerus. THE JOURNAL
OF HAND SURGERY
RADIAL
NERVE
LACERATION
must have sustained a new injury to the arm, loosening the blade which then lacerated the radial nerve which had been functioning although surrounded by fibrous tissue from the original injury. The radial nerve is the most frequently injured nerve in the arm (Barton, 1973) and fractures of the humerus are generally regarded as the commonest cause (Seddon, 1972). Other causes include lacerations, missile wounds and compression injuries. Delayed injuries to the radial nerve are uncommon but have been described in relation to metallic foreign bodies around the elbow (Friedman and Smith, 1984). The management varies according to the cause of injury and ranges from supportive splintage, while waiting for spontaneous recovery after closed injuries, to repair by primary suture of clean cuts of the
VOL.
15B No. 4 NOVEMBER
1990
TWO
YEARS
AFTER
STAB
nerve. However, when the diagnosis is uncertain, surgical exploration of the nerve is advisable to avoid unnecessary delay in recovery (Seddon, 1972; Barton, 1973). References BARTON, N. J. (1973). Radial Nerve Lesions. The Hand, 5: 3: 200-208. FRIEDMAN, R. J. and SMITH, R. J. (1984). Radial-Nerve Laceration Twentysix Years after Screw Fixation of a Humeral Fracture. A Case Report. Journal of Bone and Joint Surgery, 66A : 6: 959-960. SEDDON, Sir H. SurgicalDisordersofthePeripheralNeraes. Edinburgh, Churchill Livingstone, 1972.
Accepted: 17 March, 1989 Dr. S. Maloon, Department of Orthopaedic Surgery, University of Cape Town Medical School, Observatory 7925 Cape Town, South Africa. 0 1990 The British Society for Surgery of the Hand 02667681/90/0015-0494/$10.00
495
A 33-year-old truck driver presented with a one-week history of inability to extend his wrist or the fingers of his right hand. He denied injury, but admitted that he had been drinking on the evening before the onset of symptoms. On examination, he was found to have a complete motor and sensory deficit in the distribution of his right radial nerve below the elbow. On the lateral aspect of his distal humerus was an old well-healed scar overlying a firm mass. On direct questioning, he explained that he had been stabbed two years previously but had not sought medical treatment for the small wound which had healed rapidly. X-ray examination of the distal humerus (Fig. 1) revealed 8 ems. of a hunting-knife blade lying anterior to the humerus and embedded in new bone, confirming the length of time that the foreign body had been present. The blade appeared loose and the new bone around the tip of the blade was fractured. The differential diagnosis of the nerve injury was “Saturday night palsy” or delayed injury by the metallic
Fig. 1
494
(a) A.P. and (b) Lateral
radiographs
showing
the broken-off
foreign body. As we were unsure of the cause, the patient was initially treated conservatively with a lively extensor splint. After ten weeks there had been no improvement, so the nerve was explored. At operation, the blade was found to be quite loose and was removed with ease. The radial nerve was identified at the level of the elbow and traced proximally into dense scar tissue, where it was found to be completely divided. When the scarred nerve ends were resected, a 6 cm. defect was evident. Direct repair was not possible and, in view of the dense scar tissue bed, no graft was attempted. Two weeks later, he underwent the following tendon transfers: 1) Pronator teres to extensor carpi radialis brevis 2) flexor carpi ulnaris to extensor digitorium communis 3) palmaris longus to extensor pollicis longus. The operation was successful and within two months the patient was back at work. Discussion
In view of the length of time between the stab injury and the onset of the radial nerve palsy, we feel that our patient
end of the blade and its relationship
to the humerus. THE JOURNAL
OF HAND SURGERY
RADIAL
NERVE
LACERATION
must have sustained a new injury to the arm, loosening the blade which then lacerated the radial nerve which had been functioning although surrounded by fibrous tissue from the original injury. The radial nerve is the most frequently injured nerve in the arm (Barton, 1973) and fractures of the humerus are generally regarded as the commonest cause (Seddon, 1972). Other causes include lacerations, missile wounds and compression injuries. Delayed injuries to the radial nerve are uncommon but have been described in relation to metallic foreign bodies around the elbow (Friedman and Smith, 1984). The management varies according to the cause of injury and ranges from supportive splintage, while waiting for spontaneous recovery after closed injuries, to repair by primary suture of clean cuts of the
VOL.
15B No. 4 NOVEMBER
1990
TWO
YEARS
AFTER
STAB
nerve. However, when the diagnosis is uncertain, surgical exploration of the nerve is advisable to avoid unnecessary delay in recovery (Seddon, 1972; Barton, 1973). References BARTON, N. J. (1973). Radial Nerve Lesions. The Hand, 5: 3: 200-208. FRIEDMAN, R. J. and SMITH, R. J. (1984). Radial-Nerve Laceration Twentysix Years after Screw Fixation of a Humeral Fracture. A Case Report. Journal of Bone and Joint Surgery, 66A : 6: 959-960. SEDDON, Sir H. SurgicalDisordersofthePeripheralNeraes. Edinburgh, Churchill Livingstone, 1972.
Accepted: 17 March, 1989 Dr. S. Maloon, Department of Orthopaedic Surgery, University of Cape Town Medical School, Observatory 7925 Cape Town, South Africa. 0 1990 The British Society for Surgery of the Hand 02667681/90/0015-0494/$10.00
495