The cubital tunnel release procedure is a common surgical intervention designed to alleviate pressure on the ulnar nerve in the elbow, often referred to as the “funny bone.” This surgery is an option for individuals experiencing persistent pain, numbness, and weakness due to nerve compression that has not improved with non-surgical treatments. The procedure creates more space for the ulnar nerve as it passes through the narrow cubital tunnel at the elbow joint, aiming to restore normal nerve function and prevent long-term damage.
Understanding Cubital Tunnel Syndrome
The surgery addresses cubital tunnel syndrome, the second most frequent nerve compression issue in the upper extremity. The ulnar nerve travels from the neck down to the hand, passing through the tight cubital tunnel at the elbow. This tunnel is formed by bone, muscle, and a fibrous roof (fascia or retinaculum), which can squeeze the nerve as it passes behind the medial epicondyle, the bony bump on the inner side of the elbow.
Compression or stretching of the ulnar nerve results in uncomfortable symptoms. Patients report a tingling or “pins and needles” sensation that begins in the elbow and radiates into the hand. This tingling is felt in the ring finger and the pinky finger, as the ulnar nerve provides sensation to these digits.
Aches or sharp pain on the inside of the elbow are common complaints, often worsening when the elbow is bent for long periods, such as when driving or sleeping. Severe or chronic compression can lead to muscle weakness and difficulty with fine motor skills. This weakness affects the small muscles of the hand, potentially leading to a weakened grip or difficulty coordinating finger movements.
Activities involving repetitive elbow bending, leaning on the elbow, or sleeping with the elbow flexed can exacerbate ulnar nerve compression. If conservative measures like splinting, anti-inflammatory medications, or physical therapy fail to provide adequate relief, surgery is considered to prevent permanent nerve damage.
Defining the Cubital Tunnel Release Procedure
Cubital tunnel release is the general term for surgery performed to decompress the ulnar nerve at the elbow. The objective is to reduce the mechanical pressure acting on the nerve. This involves the surgeon accessing the cubital tunnel through an incision on the inner side of the elbow.
The “release” involves cutting or separating the constricting structures compressing the nerve. Specifically, the surgeon typically divides the thickened fascia or Osborne’s ligament that forms the roof of the cubital tunnel. This division immediately widens the space available for the ulnar nerve to pass through.
The procedure is performed on an outpatient basis under regional or general anesthesia after non-surgical treatments have been unsuccessful. By removing the source of mechanical irritation, the surgery allows the nerve to heal, leading to a gradual improvement or resolution of symptoms like numbness, pain, and weakness.
Specific Surgical Techniques for Decompression
Surgeons choose from a few distinct techniques for ulnar nerve decompression, depending on the severity of compression and the patient’s specific anatomy. The simplest approach is called simple decompression or in situ release. With this technique, the surgeon only cuts the retinaculum and fascia tight around the nerve, leaving it in its original position behind the medial epicondyle. This is often the preferred method for milder cases where the nerve is stable and does not tend to slip out of place when the elbow is moved.
If the ulnar nerve is unstable, or if the surgeon anticipates the nerve will remain under tension when the elbow is flexed, anterior ulnar nerve transposition is performed. Transposition involves moving the nerve from its location behind the bony prominence of the elbow to a new, less constricted position in front of it. This relocation prevents the nerve from being stretched or compressed as the elbow bends.
There are several ways to perform an anterior transposition, categorized by the nerve’s final resting place. The choice of transposition technique is based on the surgeon’s preference and the patient’s anatomical needs. Transposition techniques are more complex and reserved for situations where simple release is insufficient due to nerve instability or severe compression.
Types of Transposition
The nerve may be placed just under the skin and fat in the arm, called subcutaneous transposition. Alternatively, the nerve can be tucked beneath the muscle layer, known as submuscular transposition, or within the muscle itself, which is intramuscular transposition.
Post-Operative Care and Rehabilitation
Following the procedure, the arm is protected with a bulky dressing or a splint for the first few days to a week. Pain is managed with prescribed medications, though many patients find over-the-counter anti-inflammatories sufficient after the first 48 hours. The surgical site must be kept clean and dry, and the arm should be elevated above heart level to control swelling.
Light use of the hand and fingers is encouraged immediately to prevent stiffness. Patients must avoid heavy lifting, pushing, or pulling, often restricting weight to no more than a coffee cup for the initial two weeks. Driving is restricted until the patient is no longer taking narcotic pain medication and has regained sufficient comfort and control of the arm.
Physical or occupational therapy often begins within the first few weeks, focusing on restoring the full range of motion in the elbow and wrist. Rehabilitation includes nerve gliding exercises, which help the ulnar nerve move smoothly within its new or released pathway. Strength training is gradually introduced around four to six weeks post-surgery, depending on soft tissue healing. While numbness and tingling may improve quickly, the return of hand strength and sensation is a gradual process, sometimes taking 12 to 18 months for the nerve to fully regenerate.