Cubital tunnel syndrome

Question 1

What is the prognosis of carpal tunnel syndrome?

Answer 1

Treatment of CTS with nonsurgical measures or surgical decompression may lead to complete or marked improvement in 70 to 90 percent of patients by one year

Question 2

How is surgery performed for carpal tunnel syndrome?

Answer 2

• Surgery for CTS involves dividing the transverse carpal ligament and the antebrachial fascia to reduce pressure on the median nerve
• Can be performed as an open procedure, endoscopically, or by using ultrasound-guided ultra-minimally invasive techniques

Question 3

What is cubital tunnel syndrome?

Answer 3

Set of symptoms caused by compression of the ulnar nerve as it passes through the cubital tunnel

Question 4

Where does ulnar nerve entrapment occur?

Answer 4

The most common site of focal ulnar nerve entrapment or compression is at the elbow, followed by the wrist (Guyon’s canal)

Question 5

Clinical features of cubital tunnel syndrome

Answer 5

Ulnar lesions at the elbow typically present with numbness and tingling in the fourth and fifth digits, elbow pain, nocturnal awakening, and worsening of symptoms with prolonged elbow flexion

Question 6

Anatomy of cubital tunnel

Answer 6

• The ulnar nerve travels within the cubital tunnel through the two heads of the flexor carpi ulnaris muscle
• The roof of the cubital tunnel is the humeroulnar arcade proximally, and the substance of the two heads of the flexor carpi ulnaris muscle distally. The roof is formed by the arcuate ligament of Osborne
  -The floor of the tunnel is composed of the medial elbow ligaments proximally and the deep fibers of the flexor carpi ulnaris muscle more distally
• Bordered medially by the humeral and ulnar heads of the FCU, and anteriorly by the medial epicondyle

Question 7

Clinical symptoms of ulnar nerve compression

Answer 7

• Ulnar lesions at the elbow typically present with numbness and tingling in the fourth and fifth digits, elbow pain, nocturnal awakening, and worsening of symptoms with prolonged elbow flexion
• Symptoms worse at night

Question 8

What passes in guyon’s canal?

Answer 8

• Ulnar nerve, ulnar artery
• Superiorly we have the palmar carpal ligament

Question 9

How can confirm diagnosis of cubital tunnel syndrome?

Answer 9

• Tinel test (combined elbow flexion test, others exist but not very specific or sensitive)
• Electrodiagnostic testing with or without imaging

Question 10

Electrodiagnostic testing for cubital tunnel syndrome

Answer 10

• Nerve conduction studies and sometimes needle electromyography (EMG), is a standard part of the evaluation for ulnar neuropathy
• Magnetic resonance imaging and/or ultrasonography are typically used when electrodiagnostic testing is nonlocalizing or when atypical features suggest the presence of structural abnormalities associated with ulnar neuropathy

Question 11

DDx for cubital tunnel syndrome

Answer 11

Proximal lesions of the C8 or T1 roots and the lower trunk/medial cord of the brachial plexus and central nervous system lesions (rarely) such as motor neuron disease, cervical syringomyelia, and small subcortical infarctions

Question 12

Treatment for cubital tunnel syndrome

Answer 12

• Initial conservative therapy for most patients (reduce offending movements, elbow stenting at night)
• Surgical treatment (ulnar nerve decompression w/o epicondylectomy or transposition , decompression may be more effective with less complications due to lower difficulty) for severe or refractory symptoms lasting a few months not getting better with conservative treatment or progressing to worse

Question 13

How is ulnar nerve decompression performed?

Answer 13

• Performed by cutting the flexor carpi ulnaris aponeurosis (the humeroulnar arcade) to decompress the ulnar nerve
• The procedure can be performed by open or endoscopic approaches

Question 14

Epicondylectomy procedure and role in cubital tunnel syndrome?

Answer 14

• Including epicondylectomy with open in situ decompression added modest benefits in efficacy and reduced complication rates compared with decompression alone but requires longer operative time and is a more complex procedure
• Medial epicondylectomy involves removing the medial epicondyle (the bony bump on the inner side of the elbow) to alleviate compression of the ulnar nerve

Question 15

How is tinel test performed in cubital tunnel syndrome?

Answer 15

• Firm percussion over the ulnar nerve in the ulnar groove and a bit further distally over the cubital tunnel
• In addition, percussion can be applied in the upper arm 7 to 10 cm proximal to the medial epicondyle to evaluate for ulnar neuropathy along the medial intermuscular septum

Question 16

How is elbow flexion test performed

Answer 16

Sustained maximal elbow flexion for one minute with the wrist in a neutral position, while the pressure test is carried out by applying sustained manual pressure over the ulnar nerve in the ulnar groove