Unrecognized dislocation of the medial portion of the triceps: another cause of failed ulnar nerve transposition

Transcription

1 J Neurosurg 92:52 57, 2000 Unrecognized dislocation of the medial portion of the triceps: another cause of failed ulnar nerve transposition ROBERT J. SPINNER, M.D., SHAWN W. O DRISCOLL, M.D., PH.D., JESSE B. JUPITER, M.D., AND RICHARD D. GOLDNER, M.D. Departments of Neurologic Surgery and Orthopaedic Surgery, Mayo Clinic, Rochester, Minnesota; Orthopaedic Hand Service, Massachusetts General Hospital, Boston, Massachusetts; and Division of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina S Object. Failed surgical treatment for ulnar neuropathy or neuritis due to dislocation of the ulnar nerve presents diagnostic and therapeutic challenges. The authors of this paper will establish unrecognized dislocation (snapping) of the medial portion of the triceps as a preventable cause of failed ulnar nerve transposition. Methods. Fifteen patients had persistent, painful snapping at the medial elbow after ulnar nerve transposition, which had been performed for documented ulnar nerve dislocation with or without ulnar neuropathy. The snapping was caused by a previously unrecognized dislocation of the medial portion of triceps over the medial epicondyle. Seven of the 15 patients also had persistent ulnar nerve symptoms. The correct diagnosis of snapping triceps was delayed for an average of 22 months after the initial ulnar nerve transposition. An additional surgical procedure was performed in nine of the 15 cases and, in part, consisted of lateral transposition or excision of the offending snapping medial portion of the triceps. Of the four patients in this group who had persistent neurological symptoms, submuscular transposition was performed in the two with more severe symptoms and treatment of the triceps alone was performed in the two with milder neurological symptoms. Excellent results were achieved in all surgically treated patients. Six patients declined additional surgery and experienced persistent snapping and/or ulnar nerve symptoms. Conclusions. Failure to recognize that dislocation of both the medial portion of the triceps and the ulnar nerve can exist concurrently may result in persistent snapping, elbow pain, and even ulnar nerve symptoms after a technically successful ulnar nerve transposition. KEY WORDS failed ulnar nerve surgery ulnar nerve transposition snapping triceps ulnar nerve dislocation URGICAL treatment for ulnar neuritis or neuropathy poses a significant challenge. Causes of failed ulnar nerve surgery include errors in diagnosis or in technique. 1 3,7,10,13 15,22 We will establish unrecognized dislocation (snapping) of the medial portion of the triceps as another cause of failed ulnar nerve transposition. Snapping of the medial triceps 8,11,12,21,23,25 is often misdiagnosed as an isolated ulnar nerve dislocation. Because ulnar nerve symptoms are common and ulnar nerve dislocation is well known, 4 most physicians assume that ulnar nerve symptoms in a patient with a dislocating ulnar nerve are due to the dislocating nerve itself. However, symptomatic snapping of the medial portion of the triceps, which may coexist or even be the primary problem, may also persist after ulnar nerve transposition alone. Since we began to recognize this phenomenon, we have found that it is one of the most frequent causes of failed ulnar nerve transposition. Persistent snapping of the triceps must be differentiated from recurrent dislocation of the ulnar nerve, which also has been identified as a technical cause of treatment failure. 3,14,22 Abbreviation used in this paper: MR = magnetic resonance. Clinical Material and Methods Fifteen patients, 13 men and two women with an average age of 30 years (range years), were referred to our institutions shortly after ulnar nerve transposition for evaluation of persistent painful snapping at the medial aspect of the elbow (Fig. 1). In all cases, this symptom, which had been present preoperatively, was interpreted by the original treating surgeon as representing recurrent ulnar nerve dislocation, but later was proven to be due to dislocation of the medial portion of the triceps over the medial epicondyle. Ulnar nerve dislocation was documented in each of these patients before and at the initial transposition (10 subcutaneous and five submuscular procedures). In 13 of the 15 cases, symptoms and/or signs of ulnar neuropathy had also existed. The effect of elbow flexion and extension on the dynamics of the medial portion of the triceps had not been documented before or during any of the initial procedures. Two of the 15 patients were previously included in our published report on coexisting snapping of the medial triceps and dislocation of the ulnar nerve. 25 In addition to the snapping, seven patients also had persistent ulnar nerve symptoms after the transposition: four had intermittent or mild symptoms 18 (Grade I), 6 two moderate (Grade II), and one severe (Grade III). In these seven patients, electrophysiological studies were abnormal in two (one with Grade II and one with Grade III findings) and normal in five. Snapping triceps remained undiagnosed for a mean of 52

2 Snapping medial triceps and failed ulnar nerve surgery FIG. 1. Photographs of the arm of a weightlifter who experienced persistent elbow pain and snapping after undergoing two previous ulnar nerve operations. He was evaluated by eight different surgeons before a correct diagnosis of snapping of the medial portion of the triceps was made. In fact, the dislocation of the medial triceps was evident on observation of elbow flexion and the snapping could be heard. A: The elbow is passively flexed less than 90. The triceps remains posterior to the medial epicondyle. The previous elbow incision can be seen (arrow). B: The elbow is actively flexed to 90. The prominent medial triceps can be seen posterior to the medial epicondyle (arrow). C: With full active elbow flexion, the triceps has dislocated over the epicondyle (arrow). 22 months after ulnar nerve transposition (median 10 months; range 2 days 15 years). The diagnosis of snapping triceps was evident on physical examination in 10 patients; in patients who had undergone a previous ulnar nerve transposition, a contracting muscular structure that moved anteromedially over the medial epicondyle during elbow flexion was considered diagnostic of a snapping medial triceps. In three cases, the diagnosis was made at the time of surgical exploration (including two cases in which the diagnosis had been considered before the second surgery). In two patients in whom physical examination was inconclusive and secondary surgery was not performed, axial MR images of the elbow in a flexed position 26 established the diagnosis of a snapping triceps (Fig. 2). We compared these MR images with two research MR images obtained earlier in this study in two patients who had characteristic clinical findings (one of whom also had surgical confirmation). Before the correct diagnosis was determined, each patient had been evaluated on average by 3.8 surgeons (range two eight surgeons). In addition to recurrent ulnar nerve dislocation, other misdiagnoses included medial epicondylitis in three cases, medial collateral ligament laxity in two, intraarticular disease in one, and a fascial band in one. Some of these misdiagnoses resulted in complications. One patient received a steroid injection that resulted in transient ulnar neuritis. Two patients underwent additional unnecessary operative procedures: an arthrotomy in one case and a medial fascial band excision in the other. Another patient, who had undergone a subcu- FIG. 2. Magnetic resonance images obtained in a 42-year-old male violinist with a small build who presented initially with left elbow pain, snapping at the medial aspect of the elbow, and ulnar nerve symptoms. Results of preoperative electrophysiological studies were normal. After nonoperative therapy failed, the patient underwent submuscular decompression of the ulnar nerve. Snapping of the distal triceps was not identified. He had complete resolution of his neurological symptoms, with mild residual elbow snapping. He did not wish to undergo additional elbow surgery. Left: Axial T 1 -weighted MR image (TR 400 msec, TE 25 msec) obtained during elbow extension, revealing that the medial portion of the triceps (2) is posterior to the medial epicondyle (E) with the elbow fully extended. The ulnar nerve (1) has been transposed submuscularly. Right: Axial T 1 -weighted MR image (TR 700 msec, TE 25 msec) revealing that the medial portion of the triceps (2) has dislocated anteriorly over the medial epicondyle (E) (arrow) with the elbow fully flexed. The ulnar nerve (1) remains in its anterior (transposed) position. O = olecranon; U = ulna. 53

3 R. J. Spinner, et al. taneous transposition that failed, underwent a submuscular transposition 3 months later, at which time the snapping triceps still was not recognized. One patient had suicidal ideations due to persistent elbow symptoms and repeated misdiagnoses. One patient sued the primary surgeon. Reoperation addressed symptomatic snapping triceps in nine patients. Six patients declined further treatment of the snapping triceps (or their persistent ulnar nerve symptoms) once it was diagnosed correctly, despite the fact that the snapping was their original primary complaint. Of the nine patients in whom surgery was performed, snapping of the medial triceps occurred at approximately 115 of elbow flexion and was caused by the prominent medial edge of triceps muscle in seven cases and a variant tendon in two (Fig. 3). The dislocating portion of the triceps was transposed laterally in three patients and was excised in six. Four of the nine patients who underwent reoperation had persistent ulnar nerve symptoms in addition to medial snapping preoperatively after previous subcutaneous transpositions. Two had mild (Grade I), one moderate (Grade II), and one severe (Grade III) symptoms. The anterior position of the previously transposed ulnar nerve was maintained in each of these cases. These four patients had ulnar nerve compression that could be documented: in three cases by irritation of the triceps during full elbow flexion (despite the anterior position of the nerve) and in one case by fibrosis within the transposition bed. Treatment of the triceps directly decompressed the ulnar nerve in the two patients who had intermittent symptoms. The two patients with more severe ulnar nerve symptoms and signs were treated with submuscular transposition of the ulnar nerve in addition to treatment of the medial triceps. The patient with Grade III symptoms also underwent excision of a residual intermuscular septum and a medial antebrachial cutaneous neuroma. No snapping was observed with repetitive passive elbow flexion and extension intraoperatively at the conclusion of each case. FIG. 3. Intraoperative photographs obtained in a patient who had persistent pain and snapping as well as intermittent ulnar nerve symptoms after undergoing previous subcutaneous ulnar nerve transposition. The patient noted increased symptoms with repetitive resisted elbow flexion and extension (from a fully flexed position) while doing pushups. Upper: The ulnar nerve can be seen in its anterior (transposed) position (arrow) and the medial portion of the triceps is posterior to the medial epicondyle (circled with ink) with 90 of elbow flexion. The forceps holds the thickened tendinous portion of triceps that snaps over the medial epicondyle with increased elbow flexion. Center: A portion of the medial triceps has dislocated over the medial epicondyle with flexion. Note how close the triceps comes to the ulnar nerve (arrow), despite its previous transposition. Lower: A portion of the dislocating triceps was resected (arrowhead). Afterward, the triceps did not dislocate over the medial epicondyle during full elbow flexion. Results Follow-up evaluation averaged 4 years (range 1 7 years). Excellent results (no snapping, no ulnar nerve symptoms or signs, and a full range of motion) were achieved in the nine patients who eventually received treatment for the snapping triceps as well as for the dislocating ulnar nerve and ulnar neuropathy. The six patients who declined surgical treatment still experienced symptomatic snapping. Of these six patients, two had good results based on partial relief of their ulnar nerve symptoms and snapping by avoiding activities and elbow positions that aggravated the snapping; three had fair results due to persistent ulnar nerve symptoms; one patient had a poor result due to a new profound ulnar nerve palsy that developed immediately after his subcutaneous transposition. A second operation, a submuscular transposition, did not improve the ulnar neuropathy, and the snapping triceps remained undiagnosed. Discussion A review of the literature confirms the association of 54

4 Snapping medial triceps and failed ulnar nerve surgery FIG. 4. Composite drawing illustrating snapping of a portion of the medial triceps and dislocation of the ulnar nerve. A: With the elbow fully extended, both the ulnar nerve and the medial triceps are posterior to the medial epicondyle. B: With the elbow flexed approximately 90, the ulnar nerve dislocates over the medial epicondyle. C: With full elbow flexion, a portion of the medial triceps also dislocates over the medial epicondyle. By permission of Mayo Foundation. snapping medial triceps and failed ulnar nerve surgery. Three of six patients (four limbs) whose cases were reported by others 11,21,23 had failed ulnar nerve transpositions because of unrecognized snapping of the medial triceps. We believe that persistent snapping of the medial triceps after previous transposition for ulnar nerve dislocation is not uncommon and is more likely than a recurrent dislocating ulnar nerve. The diagnosis of a coexisting snapping medial triceps and dislocating ulnar nerve (with or without ulnar neuropathy) can be reliably made preoperatively during clinical examination by assessing the position of the medial triceps and the ulnar nerve referable to the medial epicondyle during passive and active elbow flexion and extension. 25 The ulnar nerve dislocates at approximately 90 and a portion of the medial head of the triceps at approximately 115 (Fig. 4). Axial MR imaging performed during elbow extension and full flexion can also demonstrate the two structures dislocating. 26 The snapping triceps and dislocating ulnar nerve can be confirmed at operation by flexing and extending the elbow. The dislocating ulnar nerve and/or the ulnar neuropathy, as well as the dislocation (snapping) of the medial triceps, should be addressed during the primary surgery. Transposition of a dislocating ulnar nerve alone does not address a symptomatic snapping medial triceps. Because the ulnar neuropathy that is associated with snapping is likely due to friction or compression by the medial triceps, treatment of the dislocating portion of the triceps alone may, in some instances, eliminate ulnar nerve compression and dislocation; this could avoid ulnar nerve transposition in individuals with snapping and intermittent or mild ulnar nerve symptoms. However, we do not recommend treatment of the dislocating portion of the triceps alone without ulnar nerve decompression and transposition if clinical and electrophysiological findings demonstrate moderate or severe ulnar nerve compression. In these instances or if the physician believes that the clinical findings warrant, the nerve should be transposed either subcutaneously or submuscularly and the triceps should be treated. As in the case of all ulnar nerve transpositions, the creation of secondary sites of compression 3,10 or painful neuroma should be avoided. 7 Anatomical variations in the triceps 5,9,16,17,19,20,24 that predispose to its dislocation should be considered during surgery. These include an accessory triceps tendon or a prominent, hypertrophied, or supernumerary triceps. 25 Treatment can consist of either lateral transposition (imbrication or rerouting) (Fig. 5) or resection (Fig. 6) of the dislocating medial portion of the triceps. We initially preferred lateral transposition of the offending portion; however, recently we have favored excision of the dislocating portion because it is easier to perform, has less risk of morbidity, provides quicker healing, and does not seem to compromise triceps function. If the dislocating portion to be resected is thought to be too large, it should be separated from the remaining triceps, rerouted laterally by weaving it through the triceps tendon, and stabilized using heavy nonabsorbable suture. Snapping of a portion of the medial triceps must be considered and investigated in every patient undergoing ulnar nerve surgery, especially in those patients with ulnar nerve dislocation. In patients with residual snapping after previous ulnar nerve transposition, one must suspect that the medial triceps is dislocating. Differentiating a recurrent dislocating ulnar nerve 14,22 from a persistent dislocating medial triceps after subcutaneous transposition can, at times, be difficult on the basis of physical examination 55

5 R. J. Spinner, et al. FIG. 5. Drawings of an operative procedure depicting redirection of the dislocating portion of the medial triceps and subcutaneous transposition of the ulnar nerve. Upper: With the elbow fully flexed, a portion of the medial triceps and the ulnar nerve have dislocated anterior to the medial epicondyle. Center: The ulnar nerve has been decompressed and has been transposed anterior to the medial epicondyle. The dislocating portion of the distal triceps has been identified and elevated from the triceps central tendon. This dislocating portion of the triceps can be either transposed laterally or resected. Lower: The triceps has been redirected into the central triceps tendon. The woven tendon has been secured using nonabsorbable suture, and the ulnar nerve has been transposed subcutaneously and stabilized using a loose fasciodermal sling. By permission of Mayo Foundation. FIG. 6. Drawings of an operative procedure illustrating excision of the dislocating portion of the medial triceps and submuscular transposition of the ulnar nerve. Upper: With the elbow fully flexed, a portion of the medial triceps and the ulnar nerve have dislocated over the medial epicondyle. Center: The dislocating portion of the triceps is being resected using an electrocautery. The decompressed ulnar nerve is protected in a rubber band. One must be certain that the triceps does not touch the nerve when using the cautery to avoid transmission of current. Lower: The altered configuration of the triceps can be seen. The ulnar nerve has been transposed submuscularly. The flexor and pronator muscles have been repaired. At the end of the operation there should be no snapping structures when the elbow is flexed and extended. By permission of Mayo Foundation. 56

6 Snapping medial triceps and failed ulnar nerve surgery alone, especially if the dislocating structure is tendinous. In these cases, the diagnosis can be established preoperatively by using MR imaging or intraoperatively. In patients who present with symptomatic snapping from a dislocating medial triceps after having undergone previous ulnar nerve transposition, one must correct the snapping and any residual cause for ulnar neuropathy. The dislocating medial triceps should be treated in the manner previously described. If neurological symptoms have persisted or recurred after the previous transposition, the ulnar nerve should be evaluated to ensure that a secondary cause of compression or irritation does not exist. One must recognize that a dislocating triceps can result in dynamic compression of the ulnar nerve after a previous subcutaneous transposition because of its proximity to the nerve. Persistent ulnar nerve symptoms may be treated by decompression of the ulnar nerve (with or without submuscular transposition) and correction of the snapping triceps. Unlike other patients who have chronic pain or neurological symptoms after an ulnar nerve procedure, the patients described in this report primarily had a mechanical problem due to the snapping, which likely causes a bursitis under the triceps. Once a proper diagnosis is determined, these patients can obtain excellent results by undergoing secondary surgery. Conclusions Snapping medial triceps must be considered in every case of primary ulnar nerve surgery, especially in those cases in which there is ulnar nerve dislocation. Our experience with dislocating medial triceps demonstrates that the majority of cases are not diagnosed initially, which is understandable considering the general lack of knowledge of this entity. Failure to recognize that dislocation of both the medial portion of the triceps and the ulnar nerve can exist concurrently can result in snapping, elbow pain, and even ulnar nerve symptoms after an otherwise successful ulnar nerve transposition. 25 References 1. Antoniadis G, Richter HP: Pain after surgery for ulnar neuropathy at the elbow: a continuing challenge. Neurosurgery 41: , Bednar MS, Blair SJ, Light TR: Complications of the treatment of cubital tunnel syndrome. Hand Clin 10:83 92, Broudy AS, Leffert RD, Smith RJ: Technical problems with ulnar nerve transposition at the elbow: findings and results of reoperation. J Hand Surg (Am) 3:85 89, Childress HM: Recurrent ulnar-nerve dislocation at the elbow. J Bone Joint Surg (Am) 38: , Dellon AL: Musculotendinous variations about the medial humeral epicondyle. J Hand Surg (Br) 11: , Dellon AL: Review of treatment results for ulnar nerve entrapment at the elbow. J Hand Surg (Am) 14: , Dellon AL, Mackinnon SE: Injury to the medial antebrachial cutaneous nerve during cubital tunnel surgery. J Hand Surg (Br) 10:33 36, Dreyfuss U, Kessler I: Snapping elbow due to dislocation of the medial head of the triceps muscle. A report of two cases. J Bone Joint Surg (Br) 60:56 57, Fabrizio PA, Clemente FR: Variation in the triceps brachii muscle: a fourth muscular head. Clin Anat 10: , Gabel GT, Amadio PC: Reoperation for failed decompression of the ulnar nerve in the region of the elbow. J Bone Joint Surg (Am) 72: , Haws M, Brown RE: Bilateral snapping triceps tendon after bilateral ulnar nerve transposition for ulnar nerve subluxation. Ann Plast Surg 34: , Hayashi Y, Kojima T, Kohno T: A case of cubital tunnel syndrome caused by the snapping of the medial head of the triceps brachii muscle. J Hand Surg (Am) 9:96 99, Holmberg J: Reoperation in high ulnar neuropathy. Scand J Plast Reconstr Hand Surg 25: , Jackson LC, Hotchkiss RN: Cubital tunnel surgery. Complications and treatment of failures. Hand Clin 12: , Jones JA: Pitfalls in the management of cubital tunnel syndrome. Orthop Rev 18:36 44, Macnicol MF: The results of operation for ulnar neuritis. J Bone Joint Surg (Br) 61: , Matsuura S, Kojima T, Kinoshita Y: Cubital tunnel syndrome caused by abnormal insertion of triceps brachii muscle. J Hand Surg (Br) 19:38 39, McGowan AJ: The results of transposition of the ulnar nerve for traumatic ulnar neuritis. J Bone Joint Surg (Br) 32: , Nigst H: Ergebnisse der operativen Behandlung der Neuropathie des N. ulnaris im Ellenbogenbereich. Handchir Mikrochir Plast Chir 15: , O Hara JJ, Stone JH: Ulnar nerve compression at the elbow caused by a prominent medial head of the triceps and an anconeus epitrochlearis muscle. J Hand Surg (Br) 21: , Reis ND: Anomalous triceps tendon as a cause for snapping elbow and ulnar neuritis: a case report. J Hand Surg 5: , Rogers MR, Bergfield TG, Aulicino PL: The failed ulnar nerve transposition. Etiology and treatment. Clin Orthop 269: , Rolfsen L: Snapping triceps tendon with ulnar neuritis. Report of a case. Acta Orthop Scand 41:74 77, Spinner RJ, Davids JR, Goldner RD: Dislocating medial triceps and ulnar neuropathy in three generations of one family. J Hand Surg (Am) 22: , Spinner RJ, Goldner RD: Snapping of the medial head of the triceps and recurrent dislocation of the ulnar nerve. Anatomic and dynamic factors. J Bone Joint Surg (Am) 80: , Spinner RJ, Hayden FR Jr, Hipps CT, et al: Imaging the snapping triceps muscle. AJR 167: , 1996 Manuscript received July 8, Accepted in final form August 30, This paper was presented at the Joint Louisiana/Mississippi Neurosurgery Society (Dean Echols Award), New Orleans, Louisiana, January 16, 1999, the Southern Neurosurgical Society meetings, Memphis, Tennessee, May 21, 1999, and the American Society for Surgery of the Hand meeting, Boston, Massachusetts, September 3, Address reprint requests to: Robert J. Spinner, M.D., Department of Neurologic Surgery, Mayo Clinic, St. Marys Hospital, Joseph 1-229E, Rochester, Minnesota spinner.robert@ mayo.edu. 57