Cubital Tunnel Syndrome
Cubital tunnel syndrome is the second most common entrapment neuropathy after carpal tunnel syndrome, resulting from compression of the ulnar nerve at the elbow and causing numbness in the ring and little fingers, hand weakness and, in advanced disease, muscle wasting. Treatment is graded by severity: conservative measures aimed at protecting the elbow in mild cases, and decompression or nerve transposition surgery in advanced cases.
Last updated: 2026-06-07
Definition
Cubital tunnel syndrome develops when the ulnar nerve is compressed at the elbow and is the second most common entrapment neuropathy after carpal tunnel syndrome. The ulnar nerve descends along the inner-posterior aspect of the arm to the elbow and passes behind the inner bony prominence of the elbow (the medial epicondyle) through a narrow passage called the cubital tunnel to reach the forearm. When the elbow is bent, the nerve is stretched in this region and the pressure within the tunnel rises; repetitive or prolonged pressure leads to chronic nerve compression.
Causes and Risk Factors
Some cases develop without an obvious cause (idiopathic). The main causes include keeping the elbow bent for prolonged or repetitive periods (during sleep, when using the phone), resting the elbow on hard surfaces, elbow trauma (medial epicondyle fracture, dislocation), an abnormal elbow angle (cubitus valgus), masses within the cubital tunnel (ganglion, lipoma) and certain anatomical variations. Systemic diseases such as diabetes, hypothyroidism and rheumatoid arthritis can increase the nerve's susceptibility to compression.
Symptoms
Early on there is numbness and tingling in the ring (4th) and little (5th) fingers and along the inner (ulnar) border of the hand; symptoms tend to increase when the elbow is bent (sleep, phone use). As the condition progresses there is weakness of the intrinsic hand muscles and impairment of grip and fine motor skills. In advanced disease, wasting of the muscles on the back of the hand and at the base of the little finger (intrinsic muscle atrophy), outward drift of the little finger (Wartenberg's sign), weakness of holding paper with the thumb (Froment's sign) and a claw-hand deformity may develop. These advanced findings often indicate a stage requiring surgery.
Diagnosis
Diagnosis is made from the clinical history and examination. Examination assesses the elbow flexion test (provoking symptoms by holding the elbow bent), the Tinel sign over the medial epicondyle, intrinsic muscle atrophy and the Wartenberg and Froment signs. Electromyography (EMG) and nerve conduction studies demonstrate slowing of ulnar nerve conduction across the elbow, grade the severity and help localize the site of compression. An elbow X-ray can show bony spurs or the sequelae of trauma, while ultrasound can show thickening of the nerve and its displacement with elbow movement (subluxation). The differential diagnosis should include cervical radiculopathy (C8-T1), Guyon's canal syndrome at the wrist and thoracic outlet syndrome.
Medical (Conservative) Treatment
Conservative treatment is the first choice in mild-to-moderate cases without muscle wasting and with short-duration symptoms. A night splint or elbow pad can be used to limit excessive bending of the elbow; it is important to avoid resting the elbow on hard surfaces and to correct elbow position during sleep and phone use. Non-steroidal anti-inflammatory drugs and ulnar nerve-gliding exercises can be supportive. Activity adjustments reduce repetitive elbow-bending movements. If there is no response to conservative treatment within a period, or if the condition is advanced, surgery comes into consideration.
Surgical Treatment
Surgery is performed in cases that do not respond to conservative treatment or that show muscle wasting or advanced findings. The main options are: simple decompression (in situ release), in which the structures compressing the nerve (Osborne's ligament and others) are divided and the nerve is left free in place; it is minimally invasive and preferred in mild-to-moderate cases without subluxation or a bony spur. Anterior transposition, in which the ulnar nerve is moved in front of the medial epicondyle to prevent it from being stretched when the elbow bends; it has subcutaneous, submuscular and intramuscular variants and is used particularly in cases of subluxation, cubitus valgus or recurrence. Medial epicondylectomy, in which part of the bony prominence is removed to relieve the nerve. The choice of method is individualized according to the site of compression, the presence of subluxation and the patient's condition. Possible side effects include numbness on the inner forearm (involvement of the medial antebrachial cutaneous nerve), wound infection and recurrence.
Prognosis and Recovery
Recovery after surgery depends on the patient's preoperative severity and the technique used. In mild-to-moderate cases numbness resolves quickly, whereas in advanced cases recovery may take months because nerve regeneration is slow. If muscle wasting has developed before surgery, strength may not fully return, so early diagnosis and treatment favourably affect the outcome. Recovery is usually longer with transposition techniques. Physiotherapy (nerve-gliding and strengthening exercises) can aid recovery. Outcomes vary from person to person and cannot be guaranteed in advance. Carpal tunnel and cubital tunnel syndrome may occur together in some patients.
References
- Greenberg MS. Greenberg's Handbook of Neurosurgery. 10th ed. Thieme; 2023:553-558.
- Winn HR, ed. Youmans Neurological Surgery. 6th ed. Saunders; 2011:2427-2439.
- Staples JR, Calfee R. Cubital Tunnel Syndrome: Current Concepts. J Am Acad Orthop Surg. 2017;25(10):e215-e224.
- Caliandro P, La Torre G, Padua R, Giannini F, Padua L. Treatment for ulnar neuropathy at the elbow. Cochrane Database Syst Rev. 2016;11(11):CD006839.
This article is for general information and does not replace a medical examination. Diagnosis and treatment decisions are individual.