Cubital tunnel syndrome
Updates to Article Attributes
Cubital tunnel syndrome is a type of ulnar nerve compression neuropathy due to pathological compression of the ulnar nerve along its course within the cubital tunnel.
Epidemiology
ItCompression of the ulnar nerve at the elbow is the second most common peripheral neuropathy of the upper extremity 1,3.
Clinical presentation
Ulnar nerve compression can result in altered sensation in the little and ring fingers. In many patients, sensory loss is often the first symptom to be reported. As the condition progresses, theythere may be hand clumsiness in the hand, as the ulnar nerve is the principal motor supply to the intrinsic muscles of the hand. In well‐established cases, there may be marked wasting of the small muscles of the hand and the ulnar‐sided muscles of the forearm 4.
Pathology
The ulnar nerve is vulnerable to stretching and compression injury as it crosses the elbow joint, which undergoes a large arc of flexion during normal range of motion. The cubital tunnel represents one of several small passages through which the ulnar nerve passes near the elbow, and is considered the most common specific site of injury 1.
During normal elbow flexion, the ulnar nerve experiences tension and axial compression due to increased pressure within the cubital tunnel, up to twenty-fold 1. Any local structural abnormality may exacerbate the mechanical forces on the nerve, which may result in neuropathy.
Other potential points of compression near the elbow include the arcade of Struthers, against the medial humeral epicondyle just proximal to the cubital tunnel, and between the humeral and ulnar heads of the flexor carpi ulnaris distal to the cubital tunnel.
Aetiology
It can arise from varyingSpecific causes whichof nerve compression at the cubital tunnel include:
- overuse
- subluxation/dislocation of the ulnar nerve from congenital laxity in fibrous tissue
- extrinsic compression
- humeral fracture with loose bodies or callus formation
- osteophytic bony spur arising from the epicondyle or olecranon
- compression from an accessory muscle, namely anconeus epitrochlearis muscle
- soft-tissue mass/tumour
- ganglion
- osteochondroma
- synovitis secondary to rheumatoid arthritis
- infective process (e.g. tuberculosis)
- haematoma
- thickened cubital tunnel retinaculum (or arcuate ligament) of the flexor carpi ulnaris muscle
Radiographic features
Exact imaging features may vary dependent on the underlying cause. Thickening of the ulnar nerve can be a commonly observed feature.
Plain radiograph
Osseous spurring within the ulnar groove can be seen in patients with chronic nerve irritation due to overuse or posteromedial elbow impingement.
Ultrasound
Ulnar nerve thickening and oedematous changes are suggestive features.
MRI
The following ulnar nerve changes within the cubital tunnel are suggestive of ulnar neuropathy:
- ulnar nerve thickening
- keep in mind that cross-sectional area of ulnar nerve varies according to degree of elbow flexion. Thus, comparison (e.g. to contralateral elbow) must be done carefully
-
ulnar nerve T2 hyperintensity
-
independently, this is non-specific and
increased T2 signal are typical MRI featuresseen in up to 60% of asymptomatic elbows - the degree of hyperintensity may be relatively higher in clinically-significant ulnar neuropathy 7
-
independently, this is non-specific and
- oedema-like signal changes or atrophy of the flexor carpi ulnaris and flexor digitorum profundus muscles may be seen secondary to ulnar neuropathy
Accurate assessment for ulnar neuropathy on MRI can be challenging, as the primary imaging features (nerve thickening, increased T2 intensity) may be present in asymptomatic cases.
Differential diagnosis
Ulnar neuropathy near the elbow may result from compression at three other sites, which may require different type of treatment:
- arcade of Struthers - a variable fascial thickening along the medial distal arm overlying the ulnar nerve
- posterior to medial humeral epicondyle (just proximal to cubital tunnel)
- between the ulnar and humeral heads of flexor carpi ulnaris (just distal to cubital tunnel)
Alternatively, the ulnar nerve may be injured at the elbow from repetitive ulnar nerve subluxation/dislocation during resisted elbow extension, e.g. bench press or pitching 1. This may presenting with medial elbow "snapping" sensation (although the snapping may actually represent associated myotendinous subluxation rather than nerve motion). The resulting friction neuropathy may cause similar presentation as cubital tunnel syndrome.
- dynamic ultrasound imaging may demonstrate ulnar nerve subluxation/dislocation across the medial humeral epicondyle in real-time
See also
-<p><strong>Cubital tunnel syndrome</strong> is a type of ulnar nerve compression neuropathy due to pathological compression of the ulnar nerve along its course within the <a href="/articles/cubital-tunnel">cubital tunnel</a>.</p><h4>Epidemiology</h4><p>It is the second most common peripheral neuropathy of the upper extremity <sup>1,3</sup>.</p><h4>Clinical presentation</h4><p>Ulnar nerve compression can result in altered sensation in the little and ring fingers. In many patients, sensory loss is often the first symptom to be reported. As the condition progresses, they may be clumsiness in the hand, as the ulnar nerve is the principal motor supply to the intrinsic muscles of the hand. In well‐established cases, there may be marked wasting of the small muscles of the hand and the ulnar‐sided muscles of the forearm <sup>4</sup>.</p><h4>Pathology</h4><h5>Aetiology</h5><p>It can arise from varying causes which include:</p><ul>- +<p><strong>Cubital tunnel syndrome</strong> is a type of ulnar nerve compression neuropathy due to pathological compression of the ulnar nerve along its course within the <a href="/articles/cubital-tunnel">cubital tunnel</a>.</p><h4>Epidemiology</h4><p>Compression of the ulnar nerve at the elbow is the second most common peripheral neuropathy of the upper extremity <sup>1,3</sup>.</p><h4>Clinical presentation</h4><p>Ulnar nerve compression can result in altered sensation in the little and ring fingers. In many patients, sensory loss is often the first symptom to be reported. As the condition progresses, there may be hand clumsiness, as the ulnar nerve is the principal motor supply to the intrinsic muscles of the hand. In well‐established cases, there may be marked wasting of the small muscles of the hand and the ulnar‐sided muscles of the forearm <sup>4</sup>.</p><h4>Pathology</h4><p>The ulnar nerve is vulnerable to stretching and compression injury as it crosses the elbow joint, which undergoes a large arc of flexion during normal range of motion. The cubital tunnel represents one of several small passages through which the ulnar nerve passes near the elbow, and is considered the most common specific site of injury <sup>1</sup>.</p><p>During normal elbow flexion, the ulnar nerve experiences tension and axial compression due to increased pressure within the cubital tunnel, up to twenty-fold <sup>1</sup>. Any local structural abnormality may exacerbate the mechanical forces on the nerve, which may result in neuropathy.</p><p>Other potential points of compression near the elbow include the <a href="/articles/arcade-of-struthers">arcade of Struthers</a>, against the <a href="/articles/humerus">medial humeral epicondyle</a> just proximal to the cubital tunnel, and between the humeral and ulnar heads of the <a href="/articles/flexor-carpi-ulnaris">flexor carpi ulnaris</a> distal to the cubital tunnel.</p><h5>Aetiology</h5><p>Specific causes of nerve compression at the cubital tunnel include:</p><ul>
-</ul><h4>Radiographic features</h4><p>Exact imaging features may vary dependent on the underlying cause. Thickening of the ulnar nerve can be a commonly observed feature. </p><h5>Plain radiograph</h5><p>Osseous spurring within the ulnar groove can be seen in patients with chronic nerve irritation due to overuse or <a title="Posteromedial impingement of elbow" href="/articles/posteromedial-elbow-impingement">posteromedial elbow impingement</a>. </p><h5>Ultrasound</h5><p>Ulnar nerve thickening and oedematous changes are suggestive features.</p><h5>MRI</h5><ul>-<li>ulnar nerve thickening and increased T2 signal are typical MRI features</li>-<li>oedema-like signal changes or atrophy of the <a title="Flexor carpi ulnaris" href="/articles/flexor-carpi-ulnaris">flexor carpi ulnaris</a> and <a title="Flexor digitorum profundus" href="/articles/flexor-digitorum-profundus-1">flexor digitorum profundus</a> muscles may be seen secondary to ulnar neuropathy</li>- +</ul><h4>Radiographic features</h4><p>Exact imaging features may vary dependent on the underlying cause. Thickening of the ulnar nerve can be a commonly observed feature. </p><h5>Plain radiograph</h5><p>Osseous spurring within the ulnar groove can be seen in patients with chronic nerve irritation due to overuse or <a href="/articles/posteromedial-elbow-impingement">posteromedial elbow impingement</a>. </p><h5>Ultrasound</h5><p>Ulnar nerve thickening and oedematous changes are suggestive features.</p><h5>MRI</h5><p>The following ulnar nerve changes within the cubital tunnel are suggestive of ulnar neuropathy:</p><ul>
- +<li>ulnar nerve thickening<ul><li>keep in mind that cross-sectional area of ulnar nerve varies according to degree of elbow flexion. Thus, comparison (e.g. to contralateral elbow) must be done carefully</li></ul>
- +</li>
- +<li>ulnar nerve T2 hyperintensity<ul>
- +<li>independently, this is non-specific and seen in up to 60% of asymptomatic elbows</li>
- +<li>the degree of hyperintensity may be relatively higher in clinically-significant ulnar neuropathy <sup>7</sup>
- +</li>
- +</ul>
- +</li>
- +<li>oedema-like signal changes or atrophy of the <a href="/articles/flexor-carpi-ulnaris">flexor carpi ulnaris</a> and <a href="/articles/flexor-digitorum-profundus-1">flexor digitorum profundus</a> muscles may be seen secondary to ulnar neuropathy</li>
- +</ul><p>Accurate assessment for ulnar neuropathy on MRI can be challenging, as the primary imaging features (nerve thickening, increased T2 intensity) may be present in asymptomatic cases. </p><h4>Differential diagnosis</h4><p>Ulnar neuropathy near the elbow may result from compression at three other sites, which may require different type of treatment:</p><ul>
- +<li>arcade of Struthers - a variable fascial thickening along the medial distal arm overlying the ulnar nerve</li>
- +<li>posterior to <a href="/articles/humerus">medial humeral epicondyle</a> (just proximal to cubital tunnel)</li>
- +<li>between the ulnar and humeral heads of <a href="/articles/flexor-carpi-ulnaris">flexor carpi ulnaris</a> (just distal to cubital tunnel)</li>
- +</ul><p>Alternatively, the ulnar nerve may be injured at the elbow from repetitive ulnar nerve subluxation/dislocation during resisted elbow extension, e.g. bench press or pitching <sup>1</sup>. This may presenting with medial elbow "snapping" sensation (although the snapping may actually represent associated myotendinous subluxation rather than nerve motion). The resulting friction neuropathy may cause similar presentation as cubital tunnel syndrome.</p><ul><li>dynamic ultrasound imaging may demonstrate ulnar nerve subluxation/dislocation across the medial humeral epicondyle in real-time</li></ul><h4>See also</h4><ul>
- +<li><a href="/articles/ulnar-nerve">ulnar nerve</a></li>
- +<li><a href="/articles/ulnar-nerve-dislocation">ulnar nerve subluxation</a></li>
References changed:
- 7. Bäumer P, Dombert T, Staub F, Kaestel T, Bartsch AJ, Heiland S, Bendszus M, Pham M. Ulnar neuropathy at the elbow: MR neurography--nerve T2 signal increase and caliber. (2011) Radiology. 260 (1): 199-206. <a href="https://doi.org/10.1148/radiol.11102357">doi:10.1148/radiol.11102357</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/21493788">Pubmed</a> <span class="ref_v4"></span>
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