July 2008.indd 223 F R A C T U R E O F S U P R A C O N D Y L A R P R O C E S S O F T H E H U M E R U S SULTAN QABOOS UNIVERSITY MEDICAL JOURNAL JULY 2008, VOLUME 8, ISSUE 2, P. 223-225 SULTAN QABOOS UNIVERSITY© SUBMITTED - 7TH FEBRUARY 2008 ACCEPTED - 15TH APRIL 2008 Department of Orthopaedics, Ibri Regional Hospital, Sultanate of Oman Email: dr.s.s.suresh@gmail.com Fracture of Supracondylar Process of the Humerus S S Suresh ABSTRACT The supracondylar process of the humerus is a rare skeletal anomaly, which is usually an incidental finding while an X- ray is done for some other purpose. The process can fracture resulting in pain and tender mobile swelling over the medial aspect of the arm, and consequent neurovascular symptoms, or entrapment neuropathies. The anomaly, which fractured in a clinical situation, is described, followed by a review of the literature. Keywords: Humeral fractures; Median nerve; Entrapment neuropathies; Osteochondroma; Case Report; Oman. العضد لعظم اللقمة فوق ما نتوء في كسر سوريش س. س. أن والنتوء ميكن ما. ــرض لغ ــينية س ــعة تؤخذ أش عندما عرضياً ما يوجد وهو غالباً نادر هيكلي ــذوذ ش هو العضد عظم في ــص: نتوء اللقمة امللخ وصف مت التقرير هذا في انحصارية. عصبية وعائية وإعتالالت – عصبية وأعراض ، للذراع ــية األنس مؤملا فوق اجلهة متحركا وورما أملا ــبباً مس ــر ينكس . الطبية األدبيات مراجعة مع سريرية حاالت في كسر مع الشذوذ هذا ، عمان. حالة تقرير ، العظم الغضروفي ، االنحصارية العصبية اإلعتالالت ، املتوسط ، العصب عضدية : كسور الكلمات مفتاح THE SUPRACONDYLAR PROCESS OF THE humerus is a rare skeletal anomaly seen in about 1 % of human beings and usually de- tected accidentally.There are many potential sites for compression of the median nerve in the arm resulting in entrapment neuropathies. The least common cause of compression is the supracondylar process and the supracondylar foramen.1 Rarely, this can present as claudication of the forearm. The spur can fracture re- sulting in painful swelling over the medial aspect of the arm. C A S E R E P O R T A forty year old man presented at Ibri Regional Hospi- tal, Oman with a painful right elbow following a road traffic accident. He had an undisplaced fracture of the ala of the sacrum, with a break in the inferior pubic ramus. There was a tender mobile swelling over the medial aspect of the distal humerus which was no- ticed on admission. There was no distal neurovascular deficit. X-rays revealed a fracture of the supracondylar process. The patient was given an arm sling for three weeks. Subsequent periodical assessment did not reveal any neurovascular compromise. D I S C U S S I O N A supracondylar process, an anomaly seen in about 1% of the population, is a bony projection found about 5- 7 cm above the medial epicondyle of the humerus. It arises from the anteromedial aspect of the distal hu- merus and is directed downward, forward and medi- ally pointing to the medial epicondyle. A fibrous band called the ligament of Struthers, is typically associated with the supracondylar spur and connects it to the medial epicondyle, thereby forming a ring. The me- dian nerve and the brachial artery pass through this. It is usually an incidental finding when X-rays are taken for some other purpose. The fibrous band of Struthers corresponds to the lower part of the tendon of the ves- tigial latissimocondyloideus muscle seen in climbing mammals.2 The supracondylar process, the fibrous C A S E R E P O R T 224 S S S U R E S H band and humerus form a foramen. This is similar to the supratrochlear foramen seen in many animals. Accessory slips of pronator teres may arise from the supracondylar process.3 The incidence varies from 1- 3.5%.4, 5 Knox in 1841 first reported its occurrence in man, as it was previously thought to be present only in animals.6 The supracondylar process was described in detail by Struthers in 1849.1, 7 In 1930, Lund pre- sented the first case of a fracture of the supracondylar process.6 The process gets fractured occasionally when it is felt as a tender mobile piece of bone just above the elbow medially and it is easily made out in radio- graphs. If it has fractured, the treatment is excision with due care to the neurovascular structures. Con- servative management is recommended if there are no neurovascular symptoms after a fracture.8 Compression of the nerve or artery can occur at many sites in the upper limb, and the least common cause of compression is the supracondylar process and the supracondylar foramen.1 The supracondylar foramen may be a site for entrapment of the brachial artery and the median nerve.3 Solieri in 19299 first de- scribed the spur and the ligament as a cause of median nerve compression. The symptomatology can mimic carpal tunnel syndrome or may cause features of clau- dication pain in the forearm. The branching pattern of the median nerve in the forearm is abnormal in those with a spur and a Struthers ligament.9 Occasionally, the ulnar nerve may be stretched over the spur and can result in ulnar nerve palsy. The symptoms are ex- aggerated by active extension and pronation of the forearm. It should be differentiated from osteochon- droma, which projects away from the elbow joint, and the bony cortex of the humerus is continuous with the tumour.10 Usually it is seen in an asymptomatic patient as a painless mass or on an X-ray taken for some other purpose. The anatomic relationship with the neurov- ascular structures is well demonstrated by magnetic resonance imaging (MRI).10 Pecina et al recommend MRI in peripheral nerve compression syndromes, and they reported an anomaly which they named “incom- plete Struthers ligament”. In their case though the liga- ment was incomplete it functioned the same way as a complete ligament.11 C O N C L U S I O N Purpose of this paper is to raise awareness of this en- tity and its clinical significance. It should also be dif- ferentiated from the osteochondromas arising from the lower medial border of the distal humerus. Distal humeral osteochondromas project away from the el- bow. In a patient with pain and sensory disturbance of the forearm and hand, the elbow should be routinely examined for the presence of a supracondylar spur. R E F E R E N C E S 1. Kessel L, Rang M. Supracondylar spur of the humerus. J Bone Joint Surg 1966; 48B:765-769. 2. Curtis JA, O’Hara AE, Carpenter GG. Spurs of the mandible and supracondylar process of the humerus in Cornelia de Lange syndrome. Am J Roentgenol 1977; 129:156-158. 3. Koshy S, Rabi S, Indrasingh I, Vettivel S. Two anatomi- cal variations associated with potential vascular entrap- ment in the upper limb. Eur J Anat 2003; 7:97-100. 4. Pieper I. On the incidence of the supracondyloid proc- Figure 1: Oblique view of the right elbow showing supracondylar process 225 F R A C T U R E O F S U P R A C O N D Y L A R P R O C E S S O F T H E H U M E R U S ess. Am J Phys Anthrop 1925; 8:169-171. 5. Doane CP. Fractures of the supracondylar process of the humerus. J Bone Joint Surg 1936; 18:757-759. 6. Newman A. The supracondylar process and its fracture. Am J Roentgenol 1969; 105:844-848. 7. Bartels RHMA, Grotenhuis JA, Kauer JMG, The arcade of Struthers: an anatomical study. Acta Neurochir 2003; 145:293-300. 8. Kolb LW, Moore RD. Fractures of the supracondylar process of the humerus-Report of two cases. J Bone Joint Surg 1967; 49:532-534. 9. Bilecenoglu B, Uz A, Karalezli N. Possible anatomic structures causing entrapment neuropathies of the me- dian nerve: An anatomic study. Acta Orthop Belg 2005; 71:169-176. 10. Lordan J, Rauh P, Spinner RJ. The clinical anatomy of the supracondylar spur and the ligament of Struthers. Clin Anat 2005; 18:548-551. 11. Pecina, Boric I, Anticevic D. Intraoperatively proven anomalous Struthers ligament diagnosed by MRI. Skel Radiol 2002; 31:532-535. Figure 2: Computed tomography scan (3-D) showing supracondylar process Figure 3: Computed tomography scan (axial view) showing healing of the supracondylar process fracture