AUTHOR AND EDITOR INFORMATION

Section 1 of 11  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• References

INTRODUCTION

Section 2 of 11  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• References

History of the Procedure

Feindel and Stratford (1958) were the first to use the term cubital tunnel. They emphasized that the ulnar nerve is compressed at the elbow because of anatomic peculiarities to that region. In 1898, Curtis performed the first published case of management for ulnar nerve neuropathy at the elbow, which consisted of a subcutaneous anterior transposition.

Problem

Affected patients often experience numbness and tingling along the little finger and the ulnar half of the ring finger. This discomfort is often accompanied by weakness of grip and, rarely, by intrinsic wasting.

Frequency

The elbow is the most common site of compression of the ulnar nerve. Cubital tunnel syndrome is the second most common compressive neuropathy (after carpal tunnel syndrome). Cubital tunnel syndrome affects men 3-8 times as often as women.

Etiology

Cubital tunnel syndrome may be caused by constricting fascial bands, subluxation of the ulnar nerve over the medial epicondyle, cubitus valgus, bony spurs, hypertrophied synovium, tumors, ganglia, or direct compression. Occupational activities may aggravate cubital tunnel syndrome secondary to repetitive elbow flexion and extension. Certain occupations are associated with the development of cubital tunnel syndrome; however, a definite relationship with occupational activities is not well defined.

Pathophysiology

As the elbow moves from extension to flexion, the distance between the medial epicondyle and the olecranon increases 5 mm for every 45° of elbow flexion. Elbow flexion places stress on the medial collateral ligament (MCL) and the overlying retinaculum. The shape of the cubital tunnel changes from a round to an oval tunnel, with a 2.5-mm loss of height, because the cubital tunnel rises during elbow flexion and the retrocondylar groove on the inferior aspect of the medial epicondyle is not as deep as the groove is posteriorly. The cubital tunnel's loss in height with flexion results in a 55% volume decrease in the canal, which further results in the mean ulnar intraneural pressure increasing from 7 mm Hg to 14 mm Hg. A combination of shoulder abduction, elbow flexion, and wrist extension results in the greatest increase in cubital tunnel pressure, with ulnar intraneural pressure increasing to about 6 times normal.

Traction and excursion of the ulnar nerve also occur during elbow flexion, as the ulnar nerve passes behind the axis of rotation of the elbow. With full range of motion (ROM) of the elbow, the ulnar nerve undergoes 9-10 mm of longitudinal excursion proximal to the medial epicondyle and 3-6 mm of excursion distal to the epicondyle. In addition, the ulnar nerve elongates 5-8 mm with elbow flexion.

Within the cubital tunnel, the measured mean intraneural pressure is significantly greater than the mean extraneural pressure at elbow flexion of 90° or more. With the elbow flexed 130°, the mean intraneural pressure is 45% higher than the mean extraneural pressure. At this amount of flexion, significant flattening of the ulnar nerve occurs; however, with full elbow flexion, no evidence exists of direct focal compression, suggesting that traction on the nerve in association with elbow flexion is responsible for the increased intraneural pressure. In addition, studies have shown that the intraneural and extraneural pressures within the cubital tunnel are lowest at 45° of flexion. As a result of these studies, 45° of flexion is considered to be the optimum position for immobilization of the elbow to decrease pressure on the ulnar nerve.

Subluxation of the ulnar nerve is a common finding. Childress (1975) looked at 2000 asymptomatic elbows. None of the patients were aware of ulnar nerve subluxation; however, 16.2% of these patients had subluxation of the ulnar nerve following flexion past 90°. Of the 325 patients with subluxation of the ulnar nerve, only 14 had unilateral subluxation. Although subluxation is a common finding and does not appear to cause cubital tunnel syndrome, the friction generated with repeated subluxation may cause inflammation within the nerve, and in the subluxed position, the nerve may be more susceptible to inadvertent trauma.

Sunderland (1987) described the internal topography of the ulnar nerve at the medial epicondyle. The sensory fibers and intrinsic muscle nerve fibers are located superficially. In contrast, the motor fibers to the flexor carpi ulnaris (FCU) and flexor digitorum profundus (FDP) are located deep within the nerve. The central location protects the motor fibers and explains why weakness of the FCU and FDP is not typically seen in ulnar neuropathy.

Proximal compression of a nerve trunk, such as that which occurs with cervical radiculopathy, may lead to increased vulnerability to nerve compression in a distal segment. This "double crush" condition can affect the ulnar nerve and results from disruption in normal axonal transport.

Histologically, severe demyelination of the nerve may occur in ulnar neuropathy. Demyelination may be located in the bulbous swelling just proximal to the entry of the nerve into the cubital tunnel.

McGowan (1950) established the following classification system:

• Grade I - Mild lesions with paresthesias in the ulnar nerve distribution and a feeling of clumsiness in the affected hand; no wasting or weakness of the intrinsic muscles
• Grade II - Intermediate lesions with weak interossei and muscle wasting
• Grade III - Severe lesions with paralysis of the interossei and a marked weakness of the hand

Clinical

Patients who are affected with cubital tunnel syndrome often experience numbness and tingling along the little finger and ulnar half of the ring finger, usually accompanied by weakness of grip. This frequently occurs when the patient rests upon or flexes the elbow. Patients may experience pain and tenderness at the level of the cubital tunnel, which may radiate proximally or distally. Symptoms vary from a vague discomfort to hypersensitivity at the elbow, and they may be intermittent at first and then become more constant. Nocturnal symptoms, especially with elbow flexion, may be quite disturbing. Patients with chronic ulnar neuropathy may complain of loss of grip and pinch strength and loss of fine dexterity. Rarely, patients with severe prolonged compression present with intrinsic muscle wasting and clawing or abduction of the little finger.

The physical examination should include the following steps:

• Check elbow ROM and examine the carrying angle; examine for areas of tenderness or ulnar nerve subluxation.
  • A positive Tinel sign finding is typically present in cubital tunnel syndrome; however, up to 24% of the asymptomatic population present with a positive Tinel sign finding.
  • The elbow flexion test is the best diagnostic test for cubital tunnel syndrome. The test involves the patient flexing the elbow past 90°, supinating the forearm, and extending the wrist. Results are positive if discomfort is reproduced or paresthesia occurs within 60 seconds. The addition of shoulder abduction may enhance the diagnostic capacity of this test.
• Palpate the cubital tunnel region to exclude mass lesions.
• Examine for intrinsic muscle weakness.
• Examine for clawing or abduction of the small finger with extension (Wartenberg sign).
• Assess ability to cross the index and middle fingers.
• Check for a Froment sign with key pinch.
• Check grip and pinch strength.
• Check vibratory perception and light touch with Semmes-Weinstein monofilaments. This is more important than static and moving 2-point discrimination tests, which reflect innervation density, as the initial changes in nerve compression affect threshold.
• Check 2-point discrimination.
• Evaluate sensation, especially the area on the ulnar dorsum of the hand supplied by the dorsal ulnar sensory nerve; hypesthesia in this area suggests a lesion proximal to the Guyon canal.
• Exclude other causes of dysesthesias and weakness along the C8-T1 distribution, such as cervical disk disease or arthritis; thoracic outlet syndrome; or ulnar nerve impingement at the Guyon canal.

Differential diagnoses include the following:

• Systemic - Diabetes, renal disease, multiple myeloma, amyloidosis, chronic alcoholism, malnutrition, leprosy, others
• Compression
  • Extrinsic – Postoperative; tourniquet; occupational or recreational activities requiring repetitive flexion or prolonged use of vibrating tools; recurrent trauma; others
  • Intrinsic - Supracondylar process, ligament of Struthers, anconeus epitrochlears, medial head of the triceps, arcuate ligament, Osborne ligament, nerve subluxation
• Valgus ligament instability
• Elbow injury and deformities - Fractures and dislocations; cubitus valgus or varus; trochlear hypoplasia
• Space occupying lesions - Ganglia, tumors, osteophytes, bursae
• Perineural adhesions
• Burns and heterotopic bone
• Arthritic conditions - Osteophytes, synovitis
• Conditions that mimic cubital tunnel - Syringomyelia, cervical disc disease, thoracic outlet syndrome, Pancoast tumor, double crush, entrapment of the nerve at the Guyon canal

INDICATIONS

Section 3 of 11  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• References

In situ decompression

Indications for in situ decompression of the ulnar nerve at the elbow are as follows:

• Mild ulnar nerve compression
• Documented mild slowing on an electromyograph (EMG) as the ulnar nerve passes into and through the proximal FCU
• Absence of pain around the medial epicondyle
• A nerve that does not sublux with elbow flexion
• Normal osseous anatomy and retrocondylar groove at the elbow and findings at surgery consistent with compression under the fibrous arcade

Simple decompression is easy to perform, and the complication rate is low. In contrast to other methods, in situ decompression avoids damage to the vascular supply of the nerve. The operation is less traumatic to the patient, and the documented results show this procedure to be as successful as other decompression procedures. In situ decompression requires minimal or no postoperative immobilization.

The advantage of in situ decompression is the ability to release the ulnar nerve in areas of compression with minimal disturbance of the blood supply. This procedure avoids subluxation of the ulnar nerve, which may lead to a recurrence of symptoms secondary to repeated contusion of the nerve as it snaps over the medial epicondyle.

The disadvantages of simple decompression are the potentially higher recurrence rate and the risk of continued subluxation of the ulnar nerve over the medial epicondyle, if that was present preoperatively.

Medial epicondylectomy

The best indication for a medial epicondylectomy is nonunion of an epicondyle fracture with ulnar nerve symptoms. Other indications include a poor bed for the ulnar nerve in the retrocondylar groove or ulnar nerve subluxation.

The advantage of a medial epicondylectomy is that it provides a more thorough decompression of the ulnar nerve than a simple release. This results in a minitransposition of the ulnar nerve. Compared to an anterior transposition, a medial epicondylectomy better preserves the blood supply to the nerve, results in less injury to the nerve, and preserves the small proximal nerve branches that might be sacrificed with an anterior transposition.

The disadvantage of a medial epicondylectomy is that it allows greater migration of the ulnar nerve with elbow flexion. A potential exists for elbow instability if the collateral ligaments are damaged. Bone pain and nerve vulnerability at the epicondylectomy site may occur. Compared to a simple decompression, the possibility of elbow stiffness or the development of an elbow flexion contracture is greater. In addition, a medial epicondylectomy is often a poor choice for athletes who throw because of the significant stresses placed on the medial aspect of the elbow joint.

Anterior transposition

The three types of anterior transposition are subcutaneous, intramuscular, and submuscular.

Indications for an ulnar nerve transposition are the following:

• An unsuitable bed for the nerve secondary to the presence of osteophytes
• A tumor
• A ganglion
• An accessory anconeus epitrochlears muscle
• Heterotopic bone
• Significant bursal tissue or other mass
• Significant tension on the ulnar nerve as implicated with a positive elbow flexion test result or symptoms aggravated by activities requiring flexion
• Subluxation of the ulnar nerve with elbow flexion
• A deformity at the elbow secondary to a valgus elbow or a tardy ulnar palsy
• The presence of valgus instability at the elbow

Soft-tissue coverage must be adequate for the transposition of the nerve and a medial elbow that is not subjected to repeated minor trauma.

The advantage of an anterior transposition is that it moves the ulnar nerve from an unsuitable bed to one that is less scarred. The nerve is effectively lengthened a few centimeters with transposition. This decreases tension on the nerve with elbow flexion.

The disadvantage of an anterior transposition is that it is more technically demanding than a simple ulnar nerve decompression. The risk of complications is increased when the nerve is moved from its natural bed, and there is a potential for devascularization of the ulnar nerve.

With an anterior subcutaneous transposition, several modifications are used to maintain the nerve in the transposed position. These include the use of epineural sutures; the creation of a fascial dermal or myofascial sling; and the creation of a subcutaneous fascial sling.

A subcutaneous transposition may be the procedure of choice in athletes who throw and do not have muscular atrophy. These athletes may lose forearm strength from a submuscular transposition and a simple decompression may not provide adequate relief of symptoms.

The advantage of a subcutaneous transposition is that it is easy to perform. It is a good procedure when subluxation and traction on the nerve are contributing to the patient's symptoms.

The disadvantage of a subcutaneous transposition is that the nerve may be hypersensitive after surgery because of its new superficial location. The potential exists for disruption of the ulnar nerve blood supply with the transposition.

Intramuscular transposition is the least popular decompression method. It yields the fewest excellent results and is associated with the most recurrences with severe ulnar nerve compression.

The advantage of an intramuscular transposition is that it buries the nerve deeply, yet provides a tunnel for the nerve to pass through. It also allows the nerve to be entirely surrounded by vascularized muscle tissue.

The disadvantage of an intramuscular transposition is that it is a complicated procedure. It involves significant soft-tissue dissection. The risk of perineural scarring is increased, and the procedure may expose the nerve to repeated muscular contractions.

A submuscular transposition offers the best results with the fewest recurrences with severe ulnar nerve compression.

A submuscular transposition is the best salvage procedure when previous surgery has failed because it places the nerve in an unscarred bed. It also works well for patients who are very thin, in whom a subcutaneous transposition may result in an area of hypersensitivity over the transposed nerve. Many consider it the procedure of choice for symptomatic athletes who throw.

Contraindications for submuscular transposition include significant scarring or distortion of the elbow joint capsule, such as in a malunited fracture or in a patient who has undergone excisional arthroplasty.

The disadvantage of a submuscular transposition is that it is a technically demanding procedure. Because of the extensive dissection involved, recovery for the patient is more difficult and the risk of elbow flexion contracture is 5-10%. Patients may also develop extensive scar formation from the procedure, and it is a difficult procedure to revise if the patient has a recurrence.

RELEVANT ANATOMY

Section 4 of 11  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• References

The ulnar nerve is the terminal branch of the medial cord of the brachial plexus and contains fibers from C8, T1, and, occasionally, C7. The ulnar nerve enters the arm with the axillary artery and passes posterior and medial to the brachial artery. The nerve travels between the brachial artery and vein. At the level of the insertion of the coracobrachialis muscle in the middle third of the arm, the ulnar nerve pierces the medial intermuscular septum (the first site of potential compression) to enter the posterior compartment of the arm. Here, the ulnar nerve lies on the anterior aspect of the medial head of the triceps, where it is joined by the superior ulnar collateral artery. The medial intermuscular septum extends from the coracobrachialis muscle proximally, where it is a thin and weak structure, to the medial humeral epicondyle, where it is a thick, distinct structure.

The next potential site of compression is the arcade of Struthers. This structure is found in 70% of patients, 8 cm proximal to the medial epicondyle, and extends from the medial intermuscular septum to the medial head of the triceps. The arcade of Struthers is formed by the attachments of the internal brachial ligament (a fascial extension of the coracobrachialis tendon), the fascia and superficial muscular fibers of the medial head of the triceps, and the medial intermuscular septum.

Next, the ulnar nerve passes through the cubital tunnel. The deep forearm investing fascia of the FCU and the arcuate ligament of Osborne, also know as the cubital tunnel retinaculum (CTR), form the roof of the cubital tunnel. The CTR is a 4 mm wide fibrous band that passes from the medial epicondyle to the tip of the olecranon. Its fibers are oriented perpendicularly to the fibers of the FCU aponeurosis, which blends with its distal margin. The elbow capsule and the posterior and transverse portions of the MCL form the floor of the cubital tunnel. The medial epicondyle and olecranon form the walls.

O'Driscoll (1991) believes that the roof of the cubital tunnel, or Osborne ligament, is a remnant of the anconeus epitrochlears muscle. He also identified a retinaculum at the proximal edge of the arcuate ligament in all but 4 of 25 cadaveric specimens. He classified this retinaculum as 1 of 4 types, as follows:

• An absent retinaculum
• A thin retinaculum that becomes tight with full flexion without compressing the nerve
• A thick retinaculum that compresses the nerve between 90° and full flexion
• An accessory anconeus epitrochlears muscle

Upon entering the cubital tunnel, the ulnar nerve gives off an articular branch to the elbow. It then passes between the humeral and ulnar heads of the FCU, the next potential site of compression. The nerve then descends into the forearm between the FCU and the FDP muscles.

About 5 cm distal to the medial epicondyle, the ulnar nerve pierces the flexor pronator aponeurosis, the fibrous common origin of the flexor and pronator muscles. The flexor-pronator aponeurosis is another point of possible compression, with compression of the ulnar nerve beneath the muscle belly of the FCU.

The ligament of Spinner is an additional aponeurosis between the flexor digitorum superficialis (FDS) of the ring finger and the humeral head of the FCU. This septum is independent of the other aponeuroses and attaches directly to the medial epicondyle and medial surface of the coronoid process of the ulna. This structure was found in 4 of 20 specimens in one study, and it is important to recognize and to release with anterior transposition of the ulnar nerve to prevent kinking.

In the forearm, the ulnar nerve extends motor branches to the FCU and the FDP of the ring and small fingers. The ulnar nerve may extend as many as 4 branches to the FCU, ranging from 4 cm above to 10 cm below the medial epicondyle. Proximal dissection of the first motor branch to the FCU from the ulnar nerve may be performed up to 6.7 cm proximal to the medial epicondyle, facilitating anterior transposition of the nerve.

An aberrant muscle, the anconeus epitrochlears, has been found in 3-28% of cadaver elbows and in as many as 9% of patients undergoing surgery for cubital tunnel syndrome. This muscle arises from the medial humeral condyle and inserts on the olecranon, crossing superficially to the ulnar nerve, where it may cause compression.

The arcade of Struthers must be differentiated from the ligament of Struthers, which is found in 1% of the population and extends from a supracondylar bony or cartilaginous spur to the medial epicondyle. This supracondylar spur can be found on the anteromedial aspect of the humerus, 5 cm proximal to the medial epicondyle, and it can often be seen on radiographs. The ligament of Struthers may occasionally cause neurovascular compression. This compression generally involves the median nerve or the brachial artery; however, the ulnar nerve can also be compressed by this structure.

Posterior branches of the medial antebrachial cutaneous nerves cross the ulnar nerve anywhere from 6 cm proximal to 4 cm distal to the medial epicondyle. These branches are often cut when making the skin incision for a cubital tunnel release, creating an area of dysesthesia or resulting in potential neuroma formation.

Extrinsic blood supply to the ulnar nerve is segmental and involves 3 vessels. These include the superior ulnar collateral artery, the inferior ulnar collateral artery, and the posterior ulnar recurrent artery. Typically, the inferior ulnar collateral artery (and often the posterior ulnar recurrent artery) is sacrificed with anterior transposition. At the level of the medial epicondyle, the inferior ulnar collateral artery is the sole blood supply to the ulnar nerve. In an anatomic study, no identifiable anastomosis was found between the superior ulnar collateral artery and the posterior ulnar recurrent arteries in 20 of 22 arms. Instead, communication between the 2 arteries occurred through proximal and distal extensions of the inferior ulnar collateral artery.

Intrinsically, the blood supply is composed of an interconnecting network of vessels that run along the fascicular branches and along each fascicle of the ulnar nerve itself. The surface microcirculation of the ulnar nerve has been shown to have an anastomotic stepladder arrangement. The inferior ulnar collateral artery is consistently found 5 mm deep to the leading edge of the medial intermuscular septum on the surface of the triceps.

Finally, acute ulnar neuropathy may have a sex predilection. This perioperative condition is found 3-8 times more frequently in men than in women. Contreras et al (1998) revealed that the medial aspect of the elbow has 2-19 times more fat content in women than in men. In men, the coronoid tubercle is approximately 1.5 times larger. He suggests that the coronoid process may be a potential site for ulnar nerve compression in men, and the increased subcutaneous fat around the ulnar nerve in women may provide a protective advantage against acute ulnar neuropathy.

The most common potential sites of compression of the ulnar nerve at the elbow are the medial intermuscular septum, the arcade of Struthers, the retrocondylar groove, the cubital tunnel, and the deep flexor-pronator aponeurosis. The 2 most common sites of compression are the retrocondylar groove and the true cubital tunnel, where the ulnar nerve passes between the 2 heads of the FCU.

CONTRAINDICATIONS

Section 5 of 11  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• References

See Indications.

WORKUP

Section 6 of 11  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• References

Imaging Studies

• Radiography
• • Obtain a cubital tunnel projection radiograph with a history of trauma or arthritis to exclude medial trochlear lip osteophytes.
  • If a supracondylar process on the medial aspect of the humerus is suspected, obtain an elbow radiograph 5 cm proximal to the medial epicondyle.
  • Obtain a chest radiograph if the patient has a history of smoking and symptoms in the ulnar nerve distribution to exclude a Pancoast tumor in the apical lung.
• Magnetic resonance imaging (MRI)
• • MRI is both sensitive and specific in the diagnosis of ulnar nerve entrapment at the elbow. It may be useful if the patient has previously undergone an anterior transposition of the ulnar nerve. On MRI, increased signal intensity is better than enlargement of the nerve for detecting ulnar nerve entrapment. A disadvantage of MRI in diagnosing cubital tunnel syndrome is its expense.
  • Britz et al (1996) examined the use of MRI in diagnosing cubital tunnel syndrome using a short tau inversion recovery sequence. They studied 31 elbows with documented ulnar nerve entrapment and found increased signal intensity in the ulnar nerve in 97% of their cases and enlargement of the ulnar nerve in 75%.
• High-resolution ultrasonography
• • High-resolution ultrasonography has been used to evaluate the morphologic changes in the ulnar nerve at the cubital tunnel in ulnar nerve neuropathy.
  • Using high-resolution ultrasonography, Chiou et al (1998) found that the mean value of the area of the ulnar nerve at the level of the medial epicondyle in symptomatic patients was significantly larger than that of the control group and that of the unaffected, contralateral side. Their P value was less than 0.001. Their conclusions were that if the area of the ulnar nerve was greater than 0.075 cm², at the level of the medial epicondyle, the patient probably had cubital tunnel syndrome.

Other Tests

• Electromyography
• • An electromyograph (EMG) is not essential when the diagnosis of cubital tunnel syndrome is obvious on clinical examination, as a false test result can be misleading; however, it is important to perform an EMG when the diagnosis of cubital tunnel syndrome is unclear or to determine the efficacy of conservative treatment.
  • EMG findings are considered positive for cubital tunnel syndrome when the motor conduction velocity across the elbow is less than 50 m/s or when the difference between the motor conduction velocity across the elbow and that below the elbow is greater than 10 m/s. During the test, it is important to stimulate the nerve over 2-cm intervals to precisely localize the area of entrapment. Compression of the ulnar nerve is probably at the level of the retrocondylar groove when the point of maximum conduction delay and drop in amplitude of the compound muscle action potential is at or just proximal to the medial epicondyle. In contrast, compression is probably in the cubital tunnel when the point of maximum conduction delay and drop in amplitude of the compound muscle action potential is 2 cm distal to the medial epicondyle. Unfortunately, false-positive results are obtained in 15% of cases.

TREATMENT

Section 7 of 11  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• References

Medical therapy

With nonoperative treatment, strengthening the elbow's flexors and extensors both isometrically and isotonically within 0-45° ROM is helpful. Limit the arc of elbow motion to an extended range to avoid ulnar nerve impingement in the cubital tunnel. Recommend that the patient decrease activities of repetition that may exacerbate symptoms. Administer nonsteroidal anti-inflammatory drugs (NSAIDs) in an attempt to decrease inflammation around the nerve. Protect the ulnar nerve from prolonged elbow flexion during sleep, and protect the nerve during the day by avoiding direct pressure or trauma.

Recommendations for initial conservative treatment for cubital tunnel are to use an elbow pad and/or night splinting for a 3-month trial period. Consider daytime immobilization for 3 weeks if symptoms do not improve with splinting. Consider surgical release if the symptoms do not improve with conservative treatment. If the symptoms do improve, continue conservative treatment for at least 6 weeks beyond the resolution of symptoms to prevent recurrence.

For mild cubital tunnel symptoms, a reversed elbow pad that covers the antecubital fossa, rather than the olecranon, serves as a reminder to the patient to maintain the elbow in an extended position and to avoid pressure on the nerve. At night, position a pillow or folded towel in the antecubital fossa to keep the elbow in an extended position. Another option is to apply a commercial soft elbow splint, with a thermoplastic insert, for persistent symptoms.

For constant pain and paresthesia, consider a rigid thermoplastic splint positioned in 45° of flexion to decrease pressure on the ulnar nerve. Initially, patients should wear this splint at all times. As symptoms subside, patients can wear the splint just at night.

Surgical therapy

If conservative therapy fails, treatment of cubital tunnel syndrome may consist of simple in situ decompression, in situ decompression with medial epicondylectomy, or anterior transposition.

Intraoperative details

Simple decompression

Make an incision about 6-10 cm in length along the course of the nerve, midway between the medial epicondyle and the tip of the olecranon. This posterior incision is recommended to avoid damage to the medial brachial and medial antebrachial cutaneous nerves. Identify and protect these nerves if encountered. Identify the ulnar nerve proximally. Release the medial intermuscular septum. Consider excising a portion of the thickened distal medial intermuscular septum to prevent kinking. Sharply divide the cubital tunnel retinaculum in a proximal-to-distal direction. Expose the ulnar nerve as it passes between the 2 heads of the FCU. Incise the fascia over the FCU. Expose the nerve as it passes through the FCU. Release the deep flexor-pronator aponeurosis. A neurolysis is not necessary.

Take the elbow through ROM, and examine the nerve for subluxation. If the nerve subluxates, consider a medial epicondylectomy or an anterior transposition. Drop the tourniquet. Obtain hemostasis. Close the subcutaneous and skin layers. Apply a simple soft compressive dressing with early active ROM.

Some believe that the nerve should not be decompressed proximally to avoid possible resultant subluxation and new compression. This risk can be reduced greatly by limiting the decompression distal to a line drawn from the medial epicondyle to the tip of the olecranon. Proximal decompression is recommended when compression is secondary to a hypertrophied medial head of the triceps or to a snapping of the medial head of the triceps with elbow flexion.

Medial epicondylectomy

Make a longitudinal incision 10-15 cm in length over the course of the nerve, and center it 1 cm anterior to the tip of the medial epicondyle. Again, identify and protect the posterior branches of the medial brachial and antebrachial cutaneous nerves and decompress the nerve as above. Make a longitudinal incision over the medial epicondyle and expose this by subperiosteal dissection. Detach the flexor pronator origin from the epicondyle and reflect it distally. Protect the nerve, and remove the medial epicondyle, or a portion of it, with an osteotome. Do not enter the elbow joint or cut the ulnar collateral ligament (UCL). Smooth sharp edges of bone with a rongeur or rasp. Close the periosteum to prevent tethering of the nerve to the raw bone surface. Reattach the flexor pronator origin with the elbow in extension to help prevent development of a flexion contracture. Allow the ulnar nerve to slide anteriorly. Apply a simple soft compressive dressing with early active ROM.

Anterior transposition

Make a longitudinal incision 15 cm in length over the course of the nerve and decompress the nerve as above. Excise 3-4 cm of the medial intermuscular septum proximal to the medial epicondyle to prevent kinking of the nerve postoperatively. Distally look for the additional, common aponeurosis between the FDS to the ring finger and the humeral head of the FCU. Excise this, if present, to prevent kinking. Identify, protect, and preserve the motor branches to the FCU and FDP. Dissect out the first motor branch to the FCU from the ulnar nerve proper if necessary to prevent kinking. Transpose the nerve into the subcutaneous plane. Examine for any remaining sites of constriction or tethering.

Several modifications are available to maintain the nerve in the transposed position. The fasciodermal sling is the most popular technique. Raise and medially reflect a 1- to 1.5-cm square flap of antebrachial fascia based on the apex of the medial epicondyle. Transpose the nerve anterior to this flap, then, suture the apex to the dermal tissue approximately 1 cm anterior to the medial epicondyle.

Another technique is to use a subcutaneous-to-fascial sling. Suture about 2 cm of the subcutaneous fascia of the anterior skin flap to the flexor-pronator fascia, just anterior to the epicondyle to keep the nerve in the transposed position.

A third option is to create a fascial sling using the medial intermuscular septum. Divide the intermuscular septum 3-4 cm proximal to its insertion on the medial epicondyle, keeping the distal attachment intact. Then, transpose the nerve. Next, use the septum as either a myofascial or fasciodermal sling to prevent posterior subluxation of the nerve. Take care to prevent kinking of the nerve at the sling. Again, apply a simple soft compressive dressing with early active ROM.

For anterior intramuscular transposition, make a longitudinal incision 15-20 cm in length over the course of the nerve and decompress the nerve as above for subcutaneous transposition. Excise the proximal border of the pronator teres and the medial intermuscular septum from the midhumerus to the elbow. Temporarily transpose the nerve and note the position of the nerve on the flexor pronator mass. Replace the nerve in the retrocondylar groove and make a 5 mm deep trough in line with the ulnar nerve in the transposed position in the flexor-pronator mass. Excise the fibrous septa separating the flexor-pronator muscles to provide a soft vascularized muscle bed. Transpose the nerve. Close the flexor-pronator fascia over the nerve with the forearm fully pronated and the elbow flexed 90°. Apply a simple soft compressive dressing with early active ROM.

For anterior submuscular transposition, make a longitudinal incision 15-20 cm in length over the course of the nerve and decompress the nerve as above for subcutaneous transposition. Raise the anterior skin flap until the bicipital aponeurosis is visualized. Incise the overlying fascia and identify and protect the median nerve. Obtaining careful hemostasis in this area is important, as there is an extensive venous system.

With the nerves protected, delineate the margins of the flexor pronator mass. Using blunt finger dissection, develop the plane between the flexor-pronator mass and the FDS and the UCL. Pass a hemostat in this plane while protecting the nerves. Incise the flexor-pronator mass in a z-cut fashion 1-2 cm distal to the medial epicondyle, and reflect this mass distally. Protect the UCL. Release the tourniquet and obtain hemostasis. Transpose the ulnar nerve adjacent and parallel to the median nerve. Reattach the lengthened flexor-pronator mass with nonabsorbable sutures with the elbow flexed and the arm pronated.

Postoperative details

Seradge (1997, 1998) found flexion contractures after medial epicondylectomy in 5% of patients who started rehabilitation at an average of postoperative day 3 and in 52% of patients who started rehabilitation at an average of postoperative day 14. Patients in the early mobilization group returned to work twice as early as those in the late mobilization group, and they did not experience any adverse effects on their grip strength or other hand functions.

Weirich (1998) studied 36 patients after subcutaneous transposition and found no difference in pain relief, weakness, patient satisfaction, grip strength, lateral pinch, or 2-point discrimination in patients who were started on immediate active ROM exercises and those who started rehabilitation an average of 14 days postoperatively. The immediate mobilization group returned to work and performed activities of daily living (ADL) earlier (median, 1 mo) than patients with delayed mobilization (median, 2.75 mo; P=0.04).

COMPLICATIONS

Section 8 of 11  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• References

The creation of a new compressive site at the time of surgery can occur with any of the decompressive methods. Injury to the posterior branches of the medial antebrachial cutaneous nerves at dissection is common. This occurred in 24% of cases in one series of 22 patients. This nerve laceration results in loss of sensibility in an area of skin posterior and distal to the incision. Some patients develop a resultant dysesthesia in the nerve distribution; others develop an amputation neuroma.

Other complications include recurrent ulnar nerve subluxation and elbow instability from damage to the elbow collateral ligaments. A postoperative flexion contracture can occur, most commonly following a submuscular transposition. This is seen after 5-10% of submuscular transpositions. Medial epicondylitis can occur from detachment of the flexor-pronator mass or as a result of a medial epicondylectomy. In addition, the symptoms may recur from an incomplete anterior transposition. Infection can occur with any surgical procedure.

After medial epicondylectomy, medial instability may occur. In an attempt to prevent medial instability, the flexor-pronator origin is carefully detached to preserve the fibers of the MCL. According to O'Driscoll et al (1991), excision of more than 20% (1-4 mm) of the width of the medial epicondyle in the coronal plane violates the important anterior band of the MCL.

Removal of the optimal amount of medial epicondyle, without creating instability, also improves results. Heithoff and Millender (1990) found in their series that a complete osteotomy resulted in 81% good and excellent results. A partial osteotomy resulted in 67% good and excellent results, and a minimal osteotomy resulted in 50% good and excellent results.

After a medial epicondylectomy, tenderness at the operative site can occur and may result in prolonged and persistent discomfort during bone healing. In addition, loss of the protection of the medial epicondyle may make the ulnar nerve more susceptible to trauma. To prevent the nerve from adhering to the osteotomy site postoperatively, it is important to preserve and close the periosteum at the end of the procedure. Weakness can occur with detachment of the flexor-pronator origin. Patients may develop an elbow flexion contracture that is often attributed to reattachment of the flexor pronator muscle origin while the elbow is flexed or from delayed or inadequate postoperative mobilization.

Complications of anterior transposition can include recurrent subluxation of the ulnar nerve. Incomplete release of fascial slings may result in new areas of compression. In one series of subcutaneous transpositions, 90% of the failures were secondary to incomplete release of the medial intermuscular septum. An ineffective sling may not maintain the position of the transposed nerve and prevent resubluxation. Scarring may occur in the new muscular channel for the nerve. Perineural fibrosis may result from an intraneural injury or a nerve transfer to a hypovascular bed. Injury to the FCU motor branches during nerve mobilization can result in potential weakness. Ligation of the posterior ulnar recurrent artery during nerve mobilization may result in nerve devascularization. A postoperative elbow flexion contracture may occur.

OUTCOME AND PROGNOSIS

Section 9 of 11  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• References

In general, every method described results in 85-90% good-to-excellent results.

Bartels et al (1998) performed a meta-analysis literature review from 1970-1997 including 3024 patients. Irrespective of preoperative status, simple decompression resulted in the best outcome. Subcutaneous and submuscular transposition had the worst outcomes. For severe compression (McGowan grade 3), anterior intramuscular transposition had the best outcome, and simple decompression and submuscular transposition had the next best outcomes.

Heithoff (1999) reviewed 14 clinical studies, covering 516 patients, in which a simple decompression was performed for cubital tunnel syndrome. Results were satisfactory in 75-92% of the patients.

Steiner et al (1996) monitored 41 patients with a simple ulnar nerve decompression for an average follow-up period of 2 years. Results were good or very good in 89% of the patients; 8% of the patients had no improvement.

Lluch (1998) studied 20 patients with an in situ decompression through a transverse incision. He noted a 24% incidence of complications from unsightly scarring and injury to the posterior branches of the medial antebrachial cutaneous nerve (MACN) in a retrospective review of 22 patients. To avoid this complication, he performed a transverse incision for the in situ decompressions. This allowed easier identification and protection of the nerve branches. In 20 patients, no problems with dysesthesia or amputation neuromas occurred, and a good cosmetic result was obtained.

Heithoff (1990) reviewed 12 clinical studies involving 350 patients in which a medial epicondylectomy was performed for cubital tunnel syndrome. Results were satisfactory in 72-94% of the patients.

Kaempffe and Farbach (1998) reviewed 27 patients with partial medial epicondylectomies who were monitored for an average of 13 months. Subjective improvement was noted in 93% of cases. Results were excellent in 8 patients, good in 10 patients, and fair in 8 patients; 1 patient had a poor result.

Seradge (1998) examined factors that influence the outcome after a medial epicondylectomy. He studied 160 patients over a 10-year period and monitored patients for 3 years postoperatively. Twenty-one patients had a recurrence, defined as a return of symptoms 3 months or longer after surgery. Of these recurrences, 44% occurred in patients in their fourth decade of life. The rate of recurrence was 18% in females and 10% in males. The rate of recurrence was double in patients who did not return to work within 3 months. When concomitant ipsilateral carpal tunnel syndrome was present, the recurrence rate was 17%, versus 9% when carpal tunnel was not present. When concomitant thoracic outlet syndrome was present, the recurrence rate was 20%, versus 9% when concomitant thoracic outlet syndrome was not present. In conclusion, he noted a high recurrence rate after medial epicondylectomy in women of middle age who had ipsilateral carpal tunnel syndrome or thoracic outlet syndrome and who did not return to work

within

3 months postoperatively.

Seradge (1997) also examined the results of medial epicondylectomy in patients on workers' compensation. These patients stayed out of work longer, used a longer period of conservative treatment without a positive impact on surgical outcome, had a less favorable surgical result, and had a higher recurrence rate.

Glowacki and Weiss (1997) reviewed the results of anterior intramuscular transpositions in patients receiving workers' compensation. Patients receiving workers' compensation had a 33% complete resolution of symptoms. In contrast, patients who were not receiving workers' compensation had a 57% complete resolution of symptoms.

Geutjens et al (1996) conducted a prospective study of 52 patients, comparing medial epicondylectomy with anterior transposition. Better results were found with medial epicondylectomy. More patients were satisfied and more stated they would have the operation again; additionally, fewer patients complained of mild pain in their hand postoperatively. No significant differences were present in motor power or nerve conduction rates at follow-up visits.

Kleinman and Bishop (1989) monitored 47 patients after anterior intramuscular transposition for an average of 28 months. Results were good or excellent in 87%, with return of normal grip strength and 2-point discrimination. No patient required reoperation.

Similarly, Glowacki and Weiss (1997) monitored 45 patients after anterior intramuscular transposition for an average of 15 months and noted resolution or improved symptoms in 87%.

Asami et al (1998) monitored 35 patients for an average of 70-72 months after an anterior intramuscular transposition, with and without preservation of the extrinsic vasculature. Nerve conduction velocities and clinical results were better in the group in which extrinsic vessels were preserved. When the extrinsic vessels were sacrificed, 3 excellent, 3 good, 4 fair, and no poor results were obtained. When the extrinsic vessels were preserved, 16 excellent, 12 good, 3 fair, and no poor results were obtained.

Nouhan and Kleinert (1997) monitored 33 limbs in 31 patients after an anterior submuscular transposition for an average of 49 months. A flexor-pronator z-lengthening technique was performed without internal neurolysis, with 36% excellent, 61% good, and 3% poor results.

Tsujino et al (1997) followed 16 patients after cubital tunnel reconstruction for ulnar nerve neuropathy in osteoarthritic elbows. A simple decompression with resection of the osteophytes from the retrocondylar groove was performed. Patients were monitored for an average of 36 months. All patients were relieved of their preoperative discomfort and had complete or partial recovery of their motor and sensory function.

FUTURE AND CONTROVERSIES

Section 10 of 11  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• References

Endoscopy of nonjoint cavities is widely performed, and endoscopic carpal tunnel release is a popular, although debated, method to release the median nerve at the wrist. With this experience, authors have attempted endoscopic cubital tunnel release. Endoscopic release allows local decompression with the ability to decompress the nerve at all potential sites of compression. The possible advantages of this technique include limited invasiveness, reduced complication rates, and quicker rehabilitation.

Tsu-Min Tsai et al (1999) performed an endoscopic cubital tunnel release on 85 elbows in 76 patients and monitored them for an average of 32 months; 42% had excellent results, 45% had good results, 11% had fair results, and 2% had poor results. These results are comparable to the other decompressive techniques used, which overall result in 85-90% good-to-excellent results.

REFERENCES

Section 11 of 11

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Contraindications
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Future And Controversies
• References

• Apfelberg DB, Larson SJ. Dynamic anatomy of the ulnar nerve at the elbow. Plast Reconstr Surg. Jan 1973;51(1):79-81. [Medline].
• Asami A, Morisawa K, Tsuruta T. Functional outcome of anterior transposition of the vascularized ulnar nerve for cubital tunnel syndrome. J Hand Surg [Br]. Oct 1998;23(5):613-6. [Medline].
• Baek GH, Kwon BC, Chung MS. Comparative study between minimal medial epicondylectomy and anterior subcutaneous transposition of the ulnar nerve for cubital tunnel syndrome. J Shoulder Elbow Surg. Sep-Oct 2006;15(5):609-13. [Medline].
• Bartels RH, Menovsky T, Van Overbeeke JJ. Surgical management of ulnar nerve compression at the elbow: an analysis of the literature. J Neurosurg. Nov 1998;89(5):722-7. [Medline].
• Bednar MS, Blair SJ, Light TR. Complications of the treatment of cubital tunnel syndrome. Hand Clin. Feb 1994;10(1):83-92. [Medline].
• Boyer M. Simple decompression did not differ from simple decompression plus anterior transposition of the nerve for cubital tunnel syndrome. J Bone Joint Surg Am. Aug 2006;88(8):1893. [Medline].
• Bozentka DJ. Cubital tunnel syndrome pathophysiology. Clin Orthop. Jun 1998;(351):90-4. [Medline].
• Britz GW, Haynor DR, Kuntz C. Ulnar nerve entrapment at the elbow: correlation of magnetic resonance imaging, clinical, electrodiagnostic, and intraoperative findings. Neurosurgery. Mar 1996;38(3):458-65; discussion 465. [Medline].
• Broudy AS, Leffert RD, Smith RJ. Technical problems with ulnar nerve transposition at the elbow: findings and results of reoperation. J Hand Surg [Am]. Jan 1978;3(1):85-9. [Medline].
• Buehler MJ, Thayer DT. The elbow flexion test. A clinical test for the cubital tunnel syndrome. Clin Orthop. Aug 1988;(233):213-6. [Medline].
• Charness ME. Unique upper extremity disorders of musicians. In: Millender, ed. Occupational Disorders of the Upper Extremity. New York, NY: Churchill Livingstone;. 1992: 227-52.
• Childress HM. Recurrent ulnar-nerve dislocation at the elbow. Clin Orthop. May 1975;(108):168-73. [Medline].
• Chiou HJ, Chou YH, Cheng SP. Cubital tunnel syndrome: diagnosis by high-resolution ultrasonography. J Ultrasound Med. Oct 1998;17(10):643-8. [Medline].
• Contreras MG, Warner MA, Charboneau WJ. Anatomy of the ulnar nerve at the elbow: potential relationship of acute ulnar neuropathy to gender differences. Clin Anat. 1998;11(6):372-8. [Medline].
• Craven PR Jr, Green DP. Cubital tunnel syndrome. Treatment by medial epicondylectomy. J Bone Joint Surg [Am]. Sep 1980;62(6):986-9. [Medline].
• Curtis BF. Traumatic Ulnar Neuritis: Transplantation of the Nerve. J Nerve Ment Dis. 1898;25:580.
• Dellon AL. Techniques for successful management of ulnar nerve entrapment at the elbow. Neurosurg Clin N Am. Jan 1991;2(1):57-73. [Medline].
• Dellon AL. Operative technique for submuscular transposition of the ulnar nerve. Contemp Orthop. 1988;16:17-24.
• Dellon AL. Review of treatment results for ulnar nerve entrapment at the elbow. J Hand Surg [Am]. Jul 1989;14(4):688-700. [Medline].
• Dellon AL. Musculotendinous variations about the medial humeral epicondyle. J Hand Surg [Br]. Jun 1986;11(2):175-81. [Medline].
• Dellon AL, Mackinnon SE. Human ulnar neuropathy at the elbow: clinical, electrical, and morphometric correlations. J Reconstr Microsurg. Apr 1988;4(3):179-84. [Medline].
• Eaton RG, Crowe JF, Parkes JC 3d. Anterior transposition of the ulnar nerve using a non-compressing fasciodermal sling. J Bone Joint Surg [Am]. Jul 1980;62(5):820-5. [Medline].
• Eisen A. Early diagnosis of ulnar nerve palsy. An electrophysiologic study. Neurology. Mar 1974;24(3):256-62. [Medline].
• Feindel W, Stratford J. The role of the cubital tunnel in tardy ulnar palsy. Can J Surg. Jul 1958;1(4):287-300. [Medline].
• Feindel W, Stratford J. Cubital tunnel compression in tardy ulnar palsy. Can Med Assoc J. Mar 1 1958;78(5):351-3. [Medline].
• Fernandez E, Pallini R, Lauretti L. Neurosurgery of the peripheral nervous system: cubital tunnel syndrome. Surg Neurol. Jul 1998;50(1):83-5. [Medline].
• Folberg CR, Weiss AP, Akelman E. Cubital tunnel syndrome. Part II: Treatment. Orthop Rev. Mar 1994;23(3):233-41. [Medline].
• Froimson AI, Anouchi YS, Seitz WH Jr. Ulnar nerve decompression with medial epicondylectomy for neuropathy at the elbow. Clin Orthop. Apr 1991;(265):200-6. [Medline].
• Gelberman RH, Yamaguchi K, Hollstien SB. Changes in interstitial pressure and cross-sectional area of the cubital tunnel and of the ulnar nerve with flexion of the elbow. An experimental study in human cadavera. J Bone Joint Surg Am. Apr 1998;80(4):492-501. [Medline].
• Gellman H, Campion DS. Modified in situ decompression of the ulnar nerve at the elbow. Hand Clin. May 1996;12(2):405-10. [Medline].
• Geutjens GG, Langstaff RJ, Smith NJ. Medial epicondylectomy or ulnar-nerve transposition for ulnar neuropathy at the elbow?. J Bone Joint Surg Br. Sep 1996;78(5):777-9. [Medline].
• Glowacki KA, Weiss AP. Anterior intramuscular transposition of the ulnar nerve for cubital tunnel syndrome. J Shoulder Elbow Surg. Mar-Apr 1997;6(2):89-96. [Medline].
• Green JR Jr, Rayan GM. The cubital tunnel: anatomic, histologic, and biomechanical study. J Shoulder Elbow Surg. Sep-Oct 1999;8(5):466-70. [Medline].
• Greenwald D, Blum LC 3rd, Adams D, et al. Effective surgical treatment of cubital tunnel syndrome based on provocative clinical testing without electrodiagnostics. Plast Reconstr Surg. Apr 15 2006;117(5):87e-91e. [Medline].
• Grewal R, Xu J, Sotereanos DG. Biomechanical properties of peripheral nerves. Hand Clin. May 1996;12(2):195-204. [Medline].
• Heithoff SJ, Millender LH, Nalebuff EA. Medial epicondylectomy for the treatment of ulnar nerve compression at the elbow. J Hand Surg [Am]. Jan 1990;15(1):22-9. [Medline].
• Heithoff SJ. Cubital tunnel syndrome does not require transposition of the ulnar nerve. J Hand Surg [Am]. Sep 1999;24(5):898-905. [Medline].
• Idler RS. General principles of patient evaluation and nonoperative management of cubital syndrome. Hand Clin. May 1996;12(2):397-403. [Medline].
• Inserra S, Spinner M. An anatomic factor significant in transposition of the ulnar nerve. J Hand Surg [Am]. Jan 1986;11(1):80-2. [Medline].
• Jackson LC, Hotchkiss RN. Cubital tunnel surgery. Complications and treatment of failures. Hand Clin. May 1996;12(2):449-56. [Medline].
• Janes PC, Mann RJ, Farnworth TK. Submuscular transposition of the ulnar nerve. Clin Orthop. Jan 1989;(238):225-32. [Medline].
• Jones RE, Gauntt C. Medial epicondylectomy for ulnar nerve compression syndrome at the elbow. Clin Orthop. Mar-Apr 1979;(139):174-8. [Medline].
• Kaempffe FA, Farbach J. A modified surgical procedure for cubital tunnel syndrome: partial medial epicondylectomy. J Hand Surg [Am]. May 1998;23(3):492-9. [Medline].
• Kanakamedala RV, Simons DG, Porter RW. Ulnar nerve entrapment at the elbow localized by short segment stimulation. Arch Phys Med Rehabil. Nov 1988;69(11):959-63. [Medline].
• Kerr AT. The brachial plexus of nerves in man; the variations in its formation and branches. Am J Anat. 1918;23:285.
• Khoo D, Carmichael SW, Spinner RJ. Ulnar nerve anatomy and compression. Orthop Clin North Am. Apr 1996;27(2):317-38. [Medline].
• Kleinman WB. Revision ulnar neuroplasty. Hand Clin. Aug 1994;10(3):461-77. [Medline].
• Kleinman WB, Bishop AT. Anterior intramuscular transposition of the ulnar nerve. J Hand Surg [Am]. Nov 1989;14(6):972-9. [Medline].
• Kleinman WB. Cubital tunnel syndrome: anterior transposition as a logical approach to complete nerve decompression. J Hand Surg [Am]. Sep 1999;24(5):886-97. [Medline].
• Kuschner SH. Cubital tunnel syndrome. Treatment by medial epicondylectomy. Hand Clin. May 1996;12(2):411-9. [Medline].
• Lim BH, Toh CL, Wong HP. Cadaveric study on the vascular anatomy of the ulnar nerve at the elbow-a basis for anterior transposition?. Ann Acad Med Singapore. Sep 1992;21(5):689-93. [Medline].
• Lluch AL. Release of ulnar nerve compression at the elbow through a transverse incision. J Shoulder Elbow Surg. Jan-Feb 1998;7(1):38-42. [Medline].
• Lundborg G, Dahlin LB. Anatomy, function, and pathophysiology of peripheral nerves and nerve compression. Hand Clin. May 1996;12(2):185-93. [Medline].
• Macnicol MF. The results of operation for ulnar neuritis. J Bone Joint Surg [Br]. May 1979;61-B(2):159-64. [Medline].
• Manske PR, Johnston R, Pruitt DL. Ulnar nerve decompression at the cubital tunnel. Clin Orthop. Jan 1992;(274):231-7. [Medline].
• Mariani PP, Golano P, Adriani E. A cadaveric study of endoscopic decompression of the cubital tunnel. Arthroscopy. Mar 1999;15(2):218-22. [Medline].
• Masear VR, Meyer RD, Pichora DR. Surgical anatomy of the medial antebrachial cutaneous nerve. J Hand Surg [Am]. Mar 1989;14(2 Pt 1):267-71. [Medline].
• McGOWAN AJ. The results of transposition of the ulnar nerve for traumatic ulnar neuritis. J Bone Joint Surg Br. Aug 1950;32-B(3):293-301. [Medline].
• McPherson SA, Meals RA. Cubital tunnel syndrome. Orthop Clin North Am. Jan 1992;23(1):111-23. [Medline].
• Neary D, Earnes R. The pathology of ulnar nerve compression in man. Neuropathol Appl Neurobiol. 1975;1:69-88.
• Nouhan R, Kleinert JM. Ulnar nerve decompression by transposing the nerve and Z-lengthening the flexor-pronator mass: clinical outcome. J Hand Surg [Am]. Jan 1997;22(1):127-31. [Medline].
• O''Driscoll SW, Horii E, Carmichael SW. The cubital tunnel and ulnar neuropathy. J Bone Joint Surg [Br]. Jul 1991;73(4):613-7. [Medline].
• Osterman AL, Davis CA. Subcutaneous transposition of the ulnar nerve for treatment of cubital tunnel syndrome. Hand Clin. May 1996;12(2):421-33. [Medline].
• Pechan J, Julis I. The pressure measurement in the ulnar nerve. A contribution to the pathophysiology of the cubital tunnel syndrome. J Biomech. Jan 1975;8(1):75-9. [Medline].
• Plancher KD, McGillicuddy JO, Kleinman WB. Anterior intramuscular transposition of the ulnar nerve. Hand Clin. May 1996;12(2):435-44. [Medline].
• Posner MA. Compressive ulnar neuropathies at the elbow: I. Etiology and diagnosis. J Am Acad Orthop Surg. Sep-Oct 1998;6(5):282-8. [Medline].
• Posner MA. Compressive ulnar neuropathies at the elbow: II. treatment. J Am Acad Orthop Surg. Sep-Oct 1998;6(5):289-97. [Medline].
• Pribyl CR, Robinson B. Use of the medial intermuscular septum as a fascial sling during anterior transposition of the ulnar nerve. J Hand Surg [Am]. May 1998;23(3):500-4. [Medline].
• Rayan GM, Jensen C, Duke J. Elbow flexion test in the normal population. J Hand Surg [Am]. Jan 1992;17(1):86-9. [Medline].
• Rettig AC, Ebben JR. Anterior subcutaneous transfer of the ulnar nerve in the athlete. Am J Sports Med. Nov-Dec 1993;21(6):836-9; discussion 839-40. [Medline].
• Sailer SM. The role of splinting and rehabilitation in the treatment of carpal and cubital tunnel syndromes. Hand Clin. May 1996;12(2):223-41. [Medline].
• Seradge H, Owen W. Cubital tunnel release with medial epicondylectomy factors influencing the outcome. J Hand Surg [Am]. May 1998;23(3):483-91. [Medline].
• Seradge H. Cubital tunnel release and medial epicondylectomy: effect of timing of mobilization. J Hand Surg [Am]. Sep 1997;22(5):863-6. [Medline].
• Siegel DB. Submuscular transposition of the ulnar nerve. Hand Clin. May 1996;12(2):445-8. [Medline].
• Siegel DB. Ulnar nerve. Applied anatomy and operative exposure. In: Operative Nerve Repair and Reconstruction. 1991:413.
• Spinner M, Kaplan EB. The relationship of the ulnar nerve to the medial intermuscular septum in the arm and its clinical significance. Hand. Oct 1976;8(3):239-42. [Medline].
• Spinner M. Nerve decompression. In: The Elbow. 1994:183-206.
• Steiner HH, von Haken MS, Steiner-Milz HG. Entrapment neuropathy at the cubital tunnel: simple decompression is the method of choice. Acta Neurochir (Wien). 1996;138(3):308-13. [Medline].
• Sunderland S, Hughes ES. Metrical and non-metrical features of the muscular branches of the ulnar nerve. J Comp Neurol. 1946;85:113.
• Sunderland S. In: Nerves and Nerve Injuries. New York, NY: Churchill Livingstone;. 1968: 816-28.
• Sunderland S. Blood supply of the nerves of the upper limb in man. Arch Neurol Psychiatry. 1945;53:91-115.
• Sunderland S. Nerves and nerve injuries. 2nd ed. New York, NY: Churchhill Livingston;1987:728-74.
• Szabo RM. Entrapment and compression neuropathies. In: Green D, Hotchkiss R, Pederson W, eds. Green's Operative Hand Surgery. Vol 2. New York, NY: Churchill Livingstone;. 1999: 1422-9.
• Tada H, Hirayama T, Katsuki M. Long term results using a modified King''s method for cubital tunnel syndrome. Clin Orthop. Mar 1997;(336):107-10. [Medline].
• Tsai TM, Chen IC, Majd ME. Cubital tunnel release with endoscopic assistance: results of a new technique. J Hand Surg [Am]. Jan 1999;24(1):21-9. [Medline].
• Tsujino A, Itoh Y, Hayashi K. Cubital tunnel reconstruction for ulnar neuropathy in osteoarthritic elbows. J Bone Joint Surg Br. May 1997;79(3):390-3. [Medline].
• Upton AR, McComas AJ. The double crush in nerve entrapment syndromes. Lancet. Aug 18 1973;2(7825):359-62. [Medline].
• Vanderpool DW, Chalmers J, Lamb DW. Peripheral compression lesions of the ulnar nerve. J Bone Joint Surg [Br]. Nov 1968;50(4):792-803. [Medline].
• Watchmaker GP, Lee G, Mackinnon SE. Intraneural topography of the ulnar nerve in the cubital tunnel facilitates anterior transposition. J Hand Surg [Am]. Nov 1994;19(6):915-22. [Medline].
• Weirich SD, Gelberman RH, Best SA. Rehabilitation after subcutaneous transposition of the ulnar nerve: immediate versus delayed mobilization. J Shoulder Elbow Surg. May-Jun 1998;7(3):244-9. [Medline].
• Wilgis EF, Murphy R. The significance of longitudinal excursion in peripheral nerves. Hand Clin. Nov 1986;2(4):761-6. [Medline].
• Yamaguchi K, Sweet FA, Bindra R. The extraosseous and intraosseous arterial anatomy of the adult elbow. J Bone Joint Surg Am. Nov 1997;79(11):1653-62. [Medline].
• Yamaguchi K, Sweet FA, Bindra R. The extraneural and intraneural arterial anatomy of the ulnar nerve at the elbow. J Shoulder Elbow Surg. Jan-Feb 1999;8(1):17-21. [Medline].

Article Last Updated: Feb 9, 2007