Patient Education and Consent
Patient instructions
The patient should be instructed to keep the wound dry, gently compressed, and elevated in the immediate postoperative period. Early mobilization of the arm is strongly encouraged and will reduce stiffness.
Some surgeons prefer slings for a few days postoperatively. Strenuous heavy lifting or the performance of repetitive tasks involving the arm is discouraged until at least the initial follow-up with the operating surgeon. This will likely require modification of lifestyle or occupational activities. Exercises may be prescribed by a hand physiotherapist. Simple analgesia should be taken as required.
The patient should seek medical attention upon any sign of infection (fever, new pain, swelling, heat, redness or ooze from the operative site) or new sensorimotor deficit.
Elements of informed consent
The patient must be made aware of the risks of ulnar nerve release. General risks include pain, infection, bleeding, thromboembolic phenomena, pressure areas, adverse reaction to anesthetic, and death. Specific risks include temporary or permanent neurologic deficit, specifically of the ulnar or nearby medial antebrachial cutaneous nerves, failure of the procedure to relieve or prevent recurrence, or even symptom exacerbation.
Preprocedural Planning
The patient will be required to attend a preoperative clinic for assessment of fitness for surgery and anesthetic (general or local). This may include blood tests, electrocardiography (ECG), and chest radiography.
History and physical examination
Individuals with ulnar neuropathy present with sensorimotor deficits in the territory of the ulnar nerve. Typically, numbness and tingling of the fingers innervated by the ulnar nerve occur first, followed by weakness. Pain may occur behind the elbow. Symptoms may be exacerbated by elbow flexion; this is especially apparent at night.
In severe cases, atrophy of the intrinsic muscles of the hand at the hypothenar eminence may develop, from mild to severe, including the Froment sign, in which the abductor pollicis is weak, so the patient tends to flex the interphalangeal (IP) joint of the thumb and extend the distal phalanx while grasping between the thumb and index finger to overcome the weakness of the abduction.
The patient can also present with a positive Wartenberg sign, in which the little finger is abducted owing to interosseous weakness. The Tinel sign may be positive at the elbow.
In severe cases, the benediction hand sign may also be seen, in which the last two fingers are less extended than the others when the patient tries to extend them all.
Neuroradiologic investigation
Electromyography (EMG) is very useful in detecting peripheral neuropathies. A nerve conduction velocity (NCV) of less than 50 m/s across the elbow is highly suggestive of a compression at that level. Patients with significantly reduced NCV and clinical findings of advanced ulnar neuropathy may show enlargement of the ulnar nerve at the medial epicondyle, which may affect surgical decision-making. [15]
Radiography is still very important in the workup of cubital syndrome, in that it helps rule out trauma, bony tumors, and osteoarthritis.
Magnetic resonance imaging (MRI) is useful for ruling out compressions of the nerve by tumors and cystic pathologies of the soft tissue and joints. [16]
High-resolution ultrasonography (HRU) may improve preoperative evaluation of ulnar neuropathy at the elbow; it is better tolerated, less costly, and less time-consuming than MRI or electrodiagnostic testing. [17]
Amyotrophic lateral sclerosis, Guillain-Barré syndrome, Charcot-Marie-Tooth disease, and hereditary neuropathy with liability to pressure palsies (HNPP) can all present with symptoms of ulnar nerve weakness and must be ruled out, as well as cervical nerve palsies, thoracic outlet syndrome, and compression of the nerve at the canal of Guyon.
Patient Preparation
Preoperative antibiotic prophylaxis has not been shown to offer benefits for uncomplicated ulnar nerve release at the cubital tunnel. [18]
Anesthesia
Some surgeons may prefer general anesthesia or regional block, especially if anterior transposition or epicondylectomy is planned. Local anesthesia is used, with 0.9% bupivacaine to close over the incision site. The wide-awake, local anesthetic, no tourniquet (WALANT) approach has been used for endoscopic cubital tunnel release. [19]
Positioning
The patient is laid supine. The arm is externally rotated and the elbow flexed to approximately 90°. The arm is exsanguinated and a pneumatic tourniquet applied.
Monitoring & Follow-up
A follow-up appointment with the clinic or general practitioner is made for 1-2 weeks after the procedure to remove sutures (if they are nonresorbable) and to assess the wound site.
Progress assessment with the operating surgeon is usually arranged for 6-8 weeks. Improvement in symptoms and hand function is generally good but varies according to the extent and duration of deficits preoperatively.
Recovery may take as long as 12 months.
