- Email: [email protected]
Entrapment of the ulnar nerve at the elbow
Entrapment of the Ulnar Nerve at the Elbow K. C. HO, MBBS (Hong Kong), FRCS (Edin), Hong Kong LEONARD MARMOR, MD, FACS,* Los Angeles, California
The ulnar nerve is commonly involved at the elbow by a variety of disorders which can produce nerve palsy. The purpose of this paper is to present two cases of ulnar entrapment due to a fibrous band proximal to the origin of the flexor carpi ulnaris. These cases are quite similar to those previously reported by Osborne [ I$]. A number of clinical syndromes have been described which are due to excessive pressure or constriction of peripheral nerves where they must pass through a tunnel, groove, or under a tough ligament [I 1. This condition has been termed an entrapment neuropathy by Thompson and Kopell [3]. Many of these are now well known but some are still unusual. Case
Reports
CASE I. A sixteen year old girl fell from a bicycle two years ago, injuring the right elbow. One year later, after she had been pitching a softball and playing tennis, pain developed in the elbow. She was treated by several orthopedists, but no improvement was noted. Roentgenograms at that time showed no abnormalities. One year later, in August 1966, the patient was still having constant pain, which would awaken her at night. The pain was described as a catching sensation that would shoot down the arm. Swelling on the medial side of the elbow was noted at times. No other joints were involved. On examination the elbow joint was tender but had a full range of motion. No neurologic signs were noted. Roentgenograms taken on August 19, 1966, showed nothing abnormal. Latex fixation and uric acid tests and sedimentation rate were within normal limits. The child continued to have severe Pain which disturbed her sleep. Re-examination revealed tenderness over the medial epicondyle outside the joint. Because of the severe symptoms, arthrotomy and exploration of the ulnar nerve at the elbow were perfo,rmed on December 15, 1966. On approaching the nerve a tight fibrous band was found constricting the nerve proximal to the flexor carpi ulnaris origin. Biopsy of the joint was carried out and the ulnar nerve was transferred anteriorly. Biopsy revealed normal synovium. The patient had an From the Department of Kong, Hong Kong. 10921 Wilshire * Address:
Volume
121,
March
1971
Orthopaedic Blvd,
Surgery.
Los Angeles,
University California
Of
90024.
Hong
uneventful recovery and all the symptoms disappeared. At examination one year later the patient had no symptoms and was physically active. CASE II. A forty year old man had fallen in August 1966, bruising the left elbow. His orthopedic consultant noted a hematoma over the medial aspect of the elbow. Roentgenograms showed nothing abnormal. The patient was asymptomatic until September 1967 when numbness and tingling developed over the ulnar distribution of ‘the fourth and fifth fingers of the left hand. This sensation increased in severity and he noted weakness in the hand. On examination three weeks after the onset of symptoms the patient had decreased sensation to pinprick and to light touch over the ulnar distribution of the left hand. Weakness was noted in the adductor of the thumb, the interossei, and the long flexor to the fourth and fifth fingers. Roentgenograms showed no abnormalities. Electromyography of the finger flexors and abductor digiti revealed normal patterns. The nerve conduction tests performed on the ulnar nerve revealed the following conduction times: at the elbow, 25 msec, below the elbow, 12 msec, at the wrist, 2.5 msec. This test localized the lesion at the elbow. The ulnar nerve was explored at the elbow on October 28, 1967. A very tight fibrous band was found constricting the ulnar nerve proximal to the origin of the flexor carpi ulnaris. (Figure 1.) This band stretched from
Figure 1. A thick fibrous band is noted in the subcutaneous tissue crossing the ulnar nerve proximal to the flexor carpi ulnaris. 355
Ho and Marmor
Figure 2. Beneath this band is a thin layer of fibrous tissue fixing the ulnar nerve tightly to the underlying tissue. The nerve appears to be kinked.
Figure 3. The ulnar nerve after release is swollen and shows the effects of the constricting band.
the medial epicondyle to the olecranon, producing a kink in the ulnar nerve. (Figure 2.) On releasing the nerve a definite constriction with swelling of the nerve above the constriction was visualized. (Figure 3.) The ulnar nerve was transferred anteriorly and a neurolysis was performed by injecting normal saline into the neural sheath. Postoperatively the sensation in the left hand improved on the third day. One month post surgery the patient’s hand was normal, and the muscle power in the finger flexors and intrinsic muscles was markedly improved. As of March 1968, he remains free of symptoms.
the fourth and fifth finger, and all the intrinsic muscles of the hand were involved. Our first case is quite unusual because of the severe pain with very little localizing symptoms or signs. Although pain has commonly been described in entrapment neuropathy, it is rare in ulnar entrapment or ulnar neuritis. The second case represents mainly sensory and motor changes without pain as a presenting symptom. The fibrous band is well documented in this case. These cases represent ulnar nerve entrapment at the elbow due to a fibrous band. In both cases trauma was noted prior to the development of symptoms.
Comments
Ulnar nerve palsy was first documented by Panas in 1878 with a report of four cases [G]. Since that time, a number of causes have been reported [1,5,6]. Thompson and Kopell [3] reported direct trauma to the nerve in the ulnar groove behind the epicondyle as a frequent cause of ulnar palsy. Osborne believed that in some of his cases ulnar palsy was due to a band of fibrous tissue bridging the two heads of the flexor carpiulnaris which tended to compress the ulnar nerve when the elbow was flexed. Barber et al [7] reported eleven cases of ulnar palsy at the elbow due to extraneural soft tissue tumors. Trauma has often been noted as the inciting cause of ulnar palsy [6]. Fiendel and Stratford [8] in 1958 coined the term “cubitaltunnel” to describe an incomplete nerve lesion resulting from gradual compression in which the small muscles of the hand are mainly affected. In their cases the hypothenar muscles were less affected and the flexor carpi ulnaris and ulnar portion of the flexor digitorum profundus were usually not involved. This syndrome is somewhat different from that in our case in which the flexor carpi ulnaris, flexor digitorum profundus to
356
Summary
Two cases of ulnar nerve entrapment at the elbow due to a fibrous band are discussed. Surgical release of the band relieved the patients’ symptoms. References 1. Osborne GV: The surgical treatment of tardy ulnar neuritis. J Bone Joint Surg 39-B: 782, 1957. 2. Osborne GV: Ulnar neuritis. Postgrad Med J 35: 392, 1959. 3. Thompson WAL, Kopell HP: Peripheral entrapment in neuropathy of the upper extremity. New Eng J Med 269: 1261,1959. 4. Silver CM, Simon SD, Silver ML, Litchman HM: The diag nosis and surgical treatment of tardy ulnar nerve palsy. J lnt Coil Surg 42: 656, 1964. 5. Brooks DM: Traumatic ulnar neuritis. J Bone Joint Surg 45-B: 445, 1963. 6. McGowan A: Transposition of the ulnar nerve for traumatic ulnar neuritis. J Bone Joint Surg 32-B: 293, 1950. 7. Barber KW, Bianco Al, Soule EH, McCarthy CS: Benign extraneural soft-tissue tumors of the extremities causing compression of nerves. J Bone Joint Surg 44-A: 98, 1962. 8. Fiendel W, Stratford J: Cubital tunnel compression in tardy ulnar palsy. Canad Med Ass J 78: 351, 1958.
The
American
Journal
of
Surgery
The ulnar nerve is commonly involved at the elbow by a variety of disorders which can produce nerve palsy. The purpose of this paper is to present two cases of ulnar entrapment due to a fibrous band proximal to the origin of the flexor carpi ulnaris. These cases are quite similar to those previously reported by Osborne [ I$]. A number of clinical syndromes have been described which are due to excessive pressure or constriction of peripheral nerves where they must pass through a tunnel, groove, or under a tough ligament [I 1. This condition has been termed an entrapment neuropathy by Thompson and Kopell [3]. Many of these are now well known but some are still unusual. Case
Reports
CASE I. A sixteen year old girl fell from a bicycle two years ago, injuring the right elbow. One year later, after she had been pitching a softball and playing tennis, pain developed in the elbow. She was treated by several orthopedists, but no improvement was noted. Roentgenograms at that time showed no abnormalities. One year later, in August 1966, the patient was still having constant pain, which would awaken her at night. The pain was described as a catching sensation that would shoot down the arm. Swelling on the medial side of the elbow was noted at times. No other joints were involved. On examination the elbow joint was tender but had a full range of motion. No neurologic signs were noted. Roentgenograms taken on August 19, 1966, showed nothing abnormal. Latex fixation and uric acid tests and sedimentation rate were within normal limits. The child continued to have severe Pain which disturbed her sleep. Re-examination revealed tenderness over the medial epicondyle outside the joint. Because of the severe symptoms, arthrotomy and exploration of the ulnar nerve at the elbow were perfo,rmed on December 15, 1966. On approaching the nerve a tight fibrous band was found constricting the nerve proximal to the flexor carpi ulnaris origin. Biopsy of the joint was carried out and the ulnar nerve was transferred anteriorly. Biopsy revealed normal synovium. The patient had an From the Department of Kong, Hong Kong. 10921 Wilshire * Address:
Volume
121,
March
1971
Orthopaedic Blvd,
Surgery.
Los Angeles,
University California
Of
90024.
Hong
uneventful recovery and all the symptoms disappeared. At examination one year later the patient had no symptoms and was physically active. CASE II. A forty year old man had fallen in August 1966, bruising the left elbow. His orthopedic consultant noted a hematoma over the medial aspect of the elbow. Roentgenograms showed nothing abnormal. The patient was asymptomatic until September 1967 when numbness and tingling developed over the ulnar distribution of ‘the fourth and fifth fingers of the left hand. This sensation increased in severity and he noted weakness in the hand. On examination three weeks after the onset of symptoms the patient had decreased sensation to pinprick and to light touch over the ulnar distribution of the left hand. Weakness was noted in the adductor of the thumb, the interossei, and the long flexor to the fourth and fifth fingers. Roentgenograms showed no abnormalities. Electromyography of the finger flexors and abductor digiti revealed normal patterns. The nerve conduction tests performed on the ulnar nerve revealed the following conduction times: at the elbow, 25 msec, below the elbow, 12 msec, at the wrist, 2.5 msec. This test localized the lesion at the elbow. The ulnar nerve was explored at the elbow on October 28, 1967. A very tight fibrous band was found constricting the ulnar nerve proximal to the origin of the flexor carpi ulnaris. (Figure 1.) This band stretched from
Figure 1. A thick fibrous band is noted in the subcutaneous tissue crossing the ulnar nerve proximal to the flexor carpi ulnaris. 355
Ho and Marmor
Figure 2. Beneath this band is a thin layer of fibrous tissue fixing the ulnar nerve tightly to the underlying tissue. The nerve appears to be kinked.
Figure 3. The ulnar nerve after release is swollen and shows the effects of the constricting band.
the medial epicondyle to the olecranon, producing a kink in the ulnar nerve. (Figure 2.) On releasing the nerve a definite constriction with swelling of the nerve above the constriction was visualized. (Figure 3.) The ulnar nerve was transferred anteriorly and a neurolysis was performed by injecting normal saline into the neural sheath. Postoperatively the sensation in the left hand improved on the third day. One month post surgery the patient’s hand was normal, and the muscle power in the finger flexors and intrinsic muscles was markedly improved. As of March 1968, he remains free of symptoms.
the fourth and fifth finger, and all the intrinsic muscles of the hand were involved. Our first case is quite unusual because of the severe pain with very little localizing symptoms or signs. Although pain has commonly been described in entrapment neuropathy, it is rare in ulnar entrapment or ulnar neuritis. The second case represents mainly sensory and motor changes without pain as a presenting symptom. The fibrous band is well documented in this case. These cases represent ulnar nerve entrapment at the elbow due to a fibrous band. In both cases trauma was noted prior to the development of symptoms.
Comments
Ulnar nerve palsy was first documented by Panas in 1878 with a report of four cases [G]. Since that time, a number of causes have been reported [1,5,6]. Thompson and Kopell [3] reported direct trauma to the nerve in the ulnar groove behind the epicondyle as a frequent cause of ulnar palsy. Osborne believed that in some of his cases ulnar palsy was due to a band of fibrous tissue bridging the two heads of the flexor carpiulnaris which tended to compress the ulnar nerve when the elbow was flexed. Barber et al [7] reported eleven cases of ulnar palsy at the elbow due to extraneural soft tissue tumors. Trauma has often been noted as the inciting cause of ulnar palsy [6]. Fiendel and Stratford [8] in 1958 coined the term “cubitaltunnel” to describe an incomplete nerve lesion resulting from gradual compression in which the small muscles of the hand are mainly affected. In their cases the hypothenar muscles were less affected and the flexor carpi ulnaris and ulnar portion of the flexor digitorum profundus were usually not involved. This syndrome is somewhat different from that in our case in which the flexor carpi ulnaris, flexor digitorum profundus to
356
Summary
Two cases of ulnar nerve entrapment at the elbow due to a fibrous band are discussed. Surgical release of the band relieved the patients’ symptoms. References 1. Osborne GV: The surgical treatment of tardy ulnar neuritis. J Bone Joint Surg 39-B: 782, 1957. 2. Osborne GV: Ulnar neuritis. Postgrad Med J 35: 392, 1959. 3. Thompson WAL, Kopell HP: Peripheral entrapment in neuropathy of the upper extremity. New Eng J Med 269: 1261,1959. 4. Silver CM, Simon SD, Silver ML, Litchman HM: The diag nosis and surgical treatment of tardy ulnar nerve palsy. J lnt Coil Surg 42: 656, 1964. 5. Brooks DM: Traumatic ulnar neuritis. J Bone Joint Surg 45-B: 445, 1963. 6. McGowan A: Transposition of the ulnar nerve for traumatic ulnar neuritis. J Bone Joint Surg 32-B: 293, 1950. 7. Barber KW, Bianco Al, Soule EH, McCarthy CS: Benign extraneural soft-tissue tumors of the extremities causing compression of nerves. J Bone Joint Surg 44-A: 98, 1962. 8. Fiendel W, Stratford J: Cubital tunnel compression in tardy ulnar palsy. Canad Med Ass J 78: 351, 1958.
The
American
Journal
of
Surgery