A case of cubital tunnel syndrome caused by the snapping of the medial head of the triceps brachii muscle A rare case of cubital tunnel syndrome caused by the snapping of the medial head of the triceps brachii muscle in a 20-year-old man was reported. The ulnar ner ve was compressed by the medial head of the triceps, which snapped from the back , and was constricted at the tendinous arch of origin of the flexor carpi ulnaris, Medial epicond ylectomy with division of tendinous arch was carried out , and the postoperative course was satisfactory. Our case is compared with four cases reported previously. ( J HAND SURG 9A:96.9, 1984.)
Yasuo Hayashi , M .D . , Tadao Koj ima, M .D., and To shihiko Kohno, M .D. , Tokyo, Japan
Reports of cubital tunnel syndrome caused by snapping of the medial head of the triceps brachii muscle are extremely rare. This study reports such a case and compares it with four cases already reported. Case report A 20-ye ar- old mal e laborer's ri ght for earm was squee zed into a n auto matic film process ing ma chine . The wound o n the palmar-ulnar side o f the middle of the forearm was immedi -
From the Department of Plastic and Reconstructive Surgery, Jikei University School of Medicine , and the Kohno Clinical Medicine Research Institute, Kitashinagawa General Hospital, Tokyo, Japan . kyo, Japan. Received for publication Dec . 7, 1982; accepted in revised form Jan. 28, 1983. Reprint requests: Yasuo Hayashi, M.D., Department of Plastic and Reconstructive Surgery, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo, 105 Japan .
a te ly sutured at a trauma hospital. We first saw the pat ient II days after the injury and found claw deformity in the hand and hypoesthesia in the ulnar nerve di stribution . We suspected a rupture of the ulnar nerve at the wound and ca rri ed out an operative ex plo rat io n o n May 4 . 1980 . Only crushing o f the bell y of the flexor d ig itorum supe r ficia lis wa s found. a nd the ulnar ner ve appe ared normal. For 2V2 months after the ope ration there was no improvement. a nd mu scul ar atrophy increased . The appearance of such marked mu scular atrophy was unexpected and led us to suspect injury of the ulnar nerve at the elbow joint level. It was known that the patient had had a previous right suprac o ndy lar fracture at the age of 12 years .
Clinical findings Claw deformity of the ring and small fingers of the right hand and significant atrophy of the dorsal interosseous (DI) muscles were noticed. Adduction of the small finger was impossible and Froment 's paper sign was positive. We noticed a lump the size of a small
Table I. Reported cases
Reference
Age /sex
Preoperative diagnosis
Operat ive findings: dislocation of the ulnar nerve
Past history of trauma
Rolfsen (1970)
2 1-year-old male
Dislocation of ulnar nerve
No records
Unclear
Dreyfuss and Kessler (1978)
25-year-old male
Dislocation of ulnar nerve plus ??? Dislocation of medial head of triceps brachii Dislocation of ulnar nerve
No records
Dislocation with triceps brachii
Supracondylar fracture
Dislocation with triceps brachii
No records
Unclear
Supracondylar fracture during childhood
Nil
26-year-old male Reis (1980)
18-year-old female
Authors
20-year-old male
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Fig. 1. With flexion of the right elbow joint, the muscle belly of the medial head of the triceps brachii muscle snapped anteriorly over the medial epicondyle.
Fig. 2. The ulnar nerve, being fixed by the tendinous arch, was strongly constricted at the tendinous arch with flexion of the elbow joint (arrow).
fingertip at the posterior region of the medial epicondyle. This lump dislocated anteriorly with flexion of the elbow joint. In the electromyographic examination, a decrease in the number of motor nerve units and an intermingling of high amplitudes were observed in the flexor carpi ulnaris, while a remarkable decrease in the spike numbers and low amplitude were observed in the abductor digiti minimi and the first DI muscle. The motor nerve conduction velocity was 34 m/sec. Slight deformity of the right medial epicondyle and a slight varus deformity were observed in the x-ray films of the elbow. The lump near the posterior region of the epicondyle was thought to be a pseudoneuroma, and the cubital tunnel syndrome was judged to have no connection to the recent trauma.
row) after detachment of the tendinous arch.
Operative findings Surgical exploration was performed 5 months after the original injury. We anticipated that with flexion of
Fig. 3. The constriction of the ulnar nerve can be seen (ar-
the elbow joint, the ulnar nerve that formed the pseudoneuroma would dislocate anteriorly. However, it was not a pseudoneuroma but the medial head of the triceps
Operative method
Results
Duration of follow-up
First operation: anterior transposition of ulnar nerve Second operation: more extensive anteposition Third operation : resection of distal and medial parts of triceps muscle tendon Detachment and transposition of medial head
Snapping persisted Snapping remained No symptoms No symptoms
I yr 9 mo
Detachment and transposition of medial head plus anterior transposition of ulnar nerve First operation : anterior transposition of ulnar nerve Second operation: excision of anomalous musculotendinous slip Medial epicondylectomy plus division of the tendinous arch
Recurrence of the snapp ing
9 mo
Snapping persisted No symptoms No symptoms
I mo No records 1'12 yr
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Hayashi et al.
brachii. With flexion of the right elbow joint, the muscle belly of the medial head of the triceps brachii muscle dislocated anteriorly over the medial epicondyle, accompanied by the snapping (Fig. 1). With flexion of the elbow joint, the ulnar nerve was subjected to strong compression from back to front by the bulge of the muscle belly. There was no mobility of the ulnar nerve since it was tethered by the tendinous arch and therefore considerably compressed (Fig. 2). After detaching the tendinous arch, the constriction in the ulnar nerve was found, and an epineurotomy was carried out (Fig. 3). A medial epicondylectomy was also performed. Passive movement of the elbow confirmed the disappearance of the snapping of the medial head of the triceps brachii and that the ulnar nerve would not be subjected to further compression.
Postoperative course One month after this operation, although hypoesthesia of the ring and small fingers were still present, the manual muscle testing for the abductor digiti minimi muscle and the first DI muscle showed improvement. Grip strengths were 19 kg in the right hand and 23 kg in the left. One and one half months after the operation, the claw deformity had disappeared, and adduction and abduction of the ring and small fingers became possible. Three months after the operation, sensory disturbance in the ulnar nerve distribution had disappeared. Manual muscle tests were normal for the abductor digiti minimi muscle and good for the first DI muscle. Grip strengths were also improved: 26 kg in the right hand and 25 kg in the left. There were no subjective symptoms Ilh years later.
Discussion Cubital tunnel syndrome caused by the snapping of the medial head of the triceps brachii was first reported by Rolfsen! in 1970. Dreyfuss and Kessler" reported two cases in 1978, and Reis" reported an additional case in 1980, for a total of four earlier reported cases. A comparison of these five cases is shown in Table I. Four of the five cases involve men. The mean age of the five patients is 22 years. Rolfsen 's 1 preoperative diagnosis was a dislocation of the ulnar nerve, while Dreyfuss and Kessler" considered that their first case was not a simple dislocation of the ulnar nerve. From the experience with their first case, they diagnosed the second case as dislocation of the medial head of the triceps brachii. Reis" diagnosed his case as caused by the snapping of the ulnar nerve.
According to Childress," the incidence of dislocation of the ulnar nerve is 16.2%, but our survey" showed it is 36.4%. Because of this high percentage incidence, there is a tendency to consider this to be the most likely diagnosis; we too thought that it was a dislocation of the ulnar nerve. Dreyfuss and Kessler, in their two cases, reported that the ulnar nerve dislocated together with the triceps brachii, but there is no clear statement about the findings in the cases of Rolfsen and Reis. In our patient, because the ulnar nerve was tightly tethered by the tendinous arch, it could not dislocate during flexion of the elbow joint. We6 have previously reported our view that dislocation of the ulnar nerve is not an important factor among the causes of the cubital tunnel syndrome. The important factor is the tendinous arch. One case of Dreyfuss and Kessler involved a varus deformity caused by the supracondylar fracture during childhood, and in our case a similar condition existed. Hence, it is thought that cubitus varus may be one of the causes of dislocation of the medial head of the triceps brachii. As for the treatment, Rolfsen and Reis at first performed anterior transposition of the ulnar nerve, but because of recurrence, partial resection of the medial head of the triceps was later carried out. In one case, Dreyfuss and Kessler detached the medial head of the triceps brachii at its insertion and then transposed and sutured it in the midline. In the second case, similar muscle transposition was done, but an anterior transposition of the ulnar nerve was also carried out. However, in their second case, a recurrence of the snapping was noticed. All cases that involved an anterior transposition of the ulnar nerve showed recurrences. Macnicol,? in a case of hypertrophy of the medial head of the triceps, at first separated the ulnar nerve from the triceps and then performed division of the tendinous arch and anterior transposition. In our case, with the division of the tendinous arch and the medial epicondylectomy, we made sure there would be no pressure on the nerve.
Conclusion Snapping of the medial head of the triceps brachii is thought to be caused by the slightly protruding medial epicondyle with varus deformity. The medial epicondylectomy and the division of the tendinous arch, which we carried out, removed the snapping and also removed the compression of the ulnar nerve. We recommend them as the most rational surgical procedures for this rare condition.
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REFERENCES 1. Rolfsen L: Snapping triceps tendon with ulnar neuritis. Acta Orthop Scand 41:74-6, 1970 2. Dreyfuss U, Kessler I: Snapping elbow due to dislocation of the medial head of triceps. J Bone Joint Surg [Br] 60:56-8, 1978 3. Reis ND: Anomalous triceps tendon as a cause for snapping elbow and ulnar neuritis: A case report. J HAND SURG 5:361-2, 1980 4. Childress HM: Recurrent ulnar-nerve dislocation at the elbow. J Bone Joint Surg [Am] 38:978-84, 1956
Cubital tunnel syndrome
5. Kojima T, Kanehara K, Shinbashi T, Nagano T: Group examination of condition and relations between the mobility of the ulnar nerve at the elbow and the degrees of the cubitus valgus. Cent Jpn J Orthop Traumat 19:215-7, 1976 6. Kojima T, Kurihara K, Nagano T: A study on operative findings and pathogenic factors in ulnar neuropathy at the elbow. Handchirurgie 11:99-104, 1979 7. Macnicol MF: The results of operation for ulnar neuritis. J Bone Joint Surg [Br] 61: 159-64, 1979
Localized constrictive radial neuropathy in the absence of extrinsic compression: Three cases Three patients, one with bilateral disease, experienced spontaneous onset of radial nerve dysfunction. Each demonstrated significant motor paralysis and had surgical exploration 3 weeks to 3 months after symptoms were first noted. AU three patients showed well-localized hourglass constrictions of the radial nerve that could not be attributed to extrinsic compression. Each subsequently required tendon transfers for a persistent radial nerve palsy. Each showed electrical evidence of late recovery, although this was incomplete in two out of three. (J HAND SURG 9A:99-103, 1984.)
John Burns, M.D., and Graham D. Lister, F.R.C.S., Houston, Texas, and Louisville, Ky.
Radial nerve palsy resulting from entrapment of the nerve or its posterior interosseous division has been described by several authors .1-7 Clinical presentation is variable, ranging from pain with a paucity of objective physical signs to frank paralysis of the affected musculature. Three cases (one bilateral) of spontaneous radial nerve palsy that were explored surgically were found to have similar hourglass constrictions totally unrelated to any compressive structure.
Case reports Case 1. A 26-year-old right-handed male personnel manager, the subject of an earlier case report," was first evaluated
From the Department of Surgery, Divisionof Orthopaedic Surgery, University of Texas, Houston, Texas. and University of Louisville School of Medicine, Louisville, Ky. Received for publication Sept. 4, 1981; accepted in revised form Dec. 13. 1982. Reprint requests: Graham D. Lister, F.R.C.S., 1001 Doctors Office Bldg., 250 E. Liberty St., Louisville, KY 40202.
on July 9, 1976. Three months before referral he had experienced insidious onset of anterolateral left elbow pain associated with early radial nerve dysfunction, confirmed clinically by his inability to actively extend all digits of his left hand and by diminished sensibility in the radial nerve sensory distribution. Electromyogram (EMG) and nerve conduction studies performed on two occasions (the last 3 months after onset of illness) confirmed absence of neural recovery. On July 19, 1976, surgical exploration of the radial nerve from just proximal to the elbow to the distal margin of the supinator revealed steroid residue from a previous injection in the area surrounding the posterior interosseous nerve. No obvious extrinsic compression was observed; saline epineurolysis showed no intrinsic constriction; microscopic internal neurolysis demonstrated normal fascicular pattern. There was no postoperative improvement, and further electromyographic examination 3 months after neurolysis showed no recovery. Appropriate tendon transfers were performed in October 1976. An EMG of the previously inactive extensor digitorum, taken in September 1982 showed almost complete recovery. A similar onset of pain and paralysis in the patient's previously uninvolved right upper extremity occurred later in the same year, 1976. Electrical studies showed an early lower
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