Intermittent axillary nerve palsy caused by a humeral exostosis

INTERMITTENT

AXILLARY HUMERAL J. WITTHAUT,

NERVE PALSY EXOSTOSIS

CAUSED

BY A

K. J. STEFFENS, and E. KOOB

From the Department of Hand and Plastic Surgery, St. Josef Hospitals, Heidbergweg, Essen-Kupferdreh, Germany

We report an uncommon case of intermittent axillary nerve palsy caused by a humeral exostosis in an 11-year-old boy. After excision of the cartilagenous exostosis of the proximal end of the left humerus, the pre-operative symptoms of axillary nerve compression were alleviated. Journal of Hand Surgery

(British and European

Volume, 1994) 19B: 4: 422-423

The axillary nerve arises from the posterior cord of the brachial plexus, its fibres being derived from the fifth and sixth cervical ventral rami. It curves back inferiorly to the humeroscapular articular capsule and traverses the quadrilateral space bounded laterally by the humeral surgical neck. The anterior branch of the axillary nerve, with the circumflex humeral vessels, curves round the humeral neck supplying the anterior part of the deltoid. The posterior branch supplies the teres minor and the posterior part of the deltoid. It continues as the upper lateral cutaneous nerve supplying the skin over the lower part of the deltoid and the upper part of the long head of the triceps. Damage to the axillary nerve causes shoulder pain, paraesthesia over the lateral aspect of the shoulder and the upper posterior part of the arm, and deltoid weakness associated with reduced shoulder abduction. Most lesions have a traumatic origin, usually subcapital humeral shaft fracture (Kwasny and Maier, 1991). An uncommon non-traumatic factor is the compression of the axillary nerve on its course through the quadrilateral space (France1 et al, 1991). We report a case caused by a humeral exostosis. Case report An 1l-year-old boy developed pain and weakness of the left shoulder during a swimming contest. Later the complaints occurred after muscular effort and any kind of overhead use of the upper limb. Resting the left arm resulted in complete relief of symptoms. As there was no history of trauma or other concurrent disease the initial diagnosis was delayed. 18 months after the first symptoms had occurred, the boy was referred to our clinic because he had developed a hard mass at the lateral upper third of the left humerus (Fig 1). Repeated abduction produced the typical signs of axillary nerve damage with deltoid weakness and pain over the lateral aspect of the shoulder. An X-ray film showed an exostosis of the upper third of the humerus (Fig 2). At operation, a large cartilaginous exostosis was found (Fig 3). Intra-operative abduction of the shoulder increased the tension on the axillary nerve. The exostosis was excised. An osteochondroma was diagnosed histologically. Follow-up over a period of 4 years confirmed that the pre-operative symptoms were entirely alleviated. 422

Fig 1

Lateral view of the left shoulder upper arm.

Fig2

X-ray showing humerus.

an exostosis

and proximal

of the upper

third

third

of the

of the left

423

AXILLARY NERVE PALSY

DISCUSSION Axillary nerve compression is rare. Mumenthaler and Schliack ( 1988) and Kwasny and Maier ( 1991) gave proximal fractures of the humerus as the most frequent cause of this condition, particularly dislocated and subluxated fractures. McKowen and Voorhies (1987) and France1 et al ( 199 1) reported uncommon cases of axillary nerve compression in the quadrilateral space. Kwasny and Maier (1991) proposed that surgery is indicated in a case of humeral shaft fracture if remission of symptoms of axillary nerve damage does not occur within 8 weeks. In the case of a clinically suspected quadrilateral space syndrome, arteriography of the posterior circumflex humeral artery provides the diagnosis and indication for surgery according to McKowen and Voorhies (1987). We conclude that, in the presence of clear-cut and localized physical findings, as in our case, an indication for operation exists without further diagnostic procedures such as electrodiagnostic studies in order to avoid any irreversible impairment of function. References FRANCEL, T. J., DELLON, A. L.

and CAMPBELL, J. N. (1991). Quadrilateral space syndrome: Diagnosis and operative decompression technique. Plastic and Reconstructive Surgery, 87: 5: 911-916. KWASNY, 0. and MAIER, R. (1991). The significance of nerve damage in upper arm fractures. Unfallchirurgie, 94: 9: 461-467. MCKOWEN, H. C. and VOORHIES, R. M. (1987). Axillary nerve entrapment in the quadrilateral space: Case report. Journal of Neurosurgery, 66: 6: 932-934. MUMENTHALER, M. and SCHLIACK, H. Liisionen Periphever Nerven. 5th Edn. Stuttgart, Thieme, 1988: 228-230.

Fig 3

A large cartilaginous exostosis of the proximal left humerus. The axillary nerve has direct contact with the exostosis and is shown above it and to the right. The orientation of the photograph is the same as in Figure 1

Accepted: 9 February 1994 Dr J. Witthaut, Department of Hand and Plastic 22-24, 45257 Essen-Kupferdreh. Gemmy. 0 1994 The British

Society

for Surgery

of the Hand

Surgery,

St Josef Hospitals,

Heidbergweg