Best Surgical Treatment for Elbow Cubital Tunnel Syndrome

Cubital tunnel syndrome is a condition that affects the ulnar nerve at the elbow. The ulnar nerve passes through the cubital tunnel just behind the inside edge of the elbow. The tunnel is formed by muscle, ligament, and bone. You may be able to feel it if you straighten your arm out and rub the groove on the inside edge of your elbow.

Cubital tunnel syndrome has several possible causes. Part of the problem may lie in the way the elbow works. The ulnar nerve actually stretches several millimeters when the elbow is bent. Sometimes the nerve will shift or even snap over the bony medial epicondyle. (The medial epicondyle is the bony point on the inside edge of the elbow.) Over time, this can cause irritation.

What is actually happening to cause this condition? Experts think it's a combination of compression (pressure) and traction (pull or stretch) on the nerve. Elbow flexion (bending the elbow) increases these effects. Frequent bending of the elbow, such as pulling levers, reaching, or lifting may contribute to the problem. Constant direct pressure on the elbow over time may also lead to cubital tunnel syndrome. The nerve can be irritated from leaning on the elbow while you sit at a desk or from using the elbow rest during a long drive or while running machinery. The ulnar nerve can also be damaged from a blow to the cubital tunnel.

The symptoms are very similar to the pain or electric shock sensation that comes from hitting your funny bone. When you hit your funny bone, you are actually hitting the ulnar nerve on the inside of the elbow. Numbness on the inside of the hand and in the ring and little fingers is an early sign of cubital tunnel syndrome. The numbness is often felt when the elbows are bent for long periods, such as when talking on the phone or while sleeping. The hand and thumb may also become clumsy as the muscles become affected.

Treatment begins with conservative (nonoperative) care, which often resolves the symptoms. But when symptoms persist and do not respond to splinting or stretching activities, then surgery may be needed. The surgeon has several choices when deciding how to do the surgery. The first is a local (called in situ) release of the structures pressing on the nerve.

The second is to move (transpose) the nerve to a new location (away from the structures pressing on it). The third is to perform a medial epicondylectomy (removal of the bone along the inside of the elbow). And the fourth is the subject of this article: the Hoffmann technique. The Hoffmann technique is an endoscopic approach from 10 centimeters (about four inches) below the elbow, releasing the nerve all the way up to 10 centimeters above the elbow.

The advantages of this surgical approach are that it enables the surgeon to look down on the nerve (and the soft tissues around it). Using the endoscope inserted into the forearm through the skin, the surgeon can have direct vision of the nerve. The ligament most often pressing on the nerve (arcuate or Osborne's) is cut much like the in situ release. But the surgeon is also able to release other areas where the fascial bands (connective tissue) underneath the muscles are compressing or entrapping the nerve.

Not everyone is a good candidate for this surgical technique. But the Hoffmann technique can be considered for most patients who have not responded well to conservative care. The exceptions include anyone with osteoarthritis with loss of elbow motion due to bone spurs. It's the bone spurs that are putting pressure on the nerve and these must be removed. A more open, extensive surgery is required to shave and smooth the bone.

Severe elbow deformity known as cubital valgus (increased angle of the elbow) as a result of osteoarthritis prevents the use of the Hoffmann technique. And patients whose ulnar nerve pops in and out of the tunnel with painful symptoms may only need an in situ procedure rather than the more extensive Hoffmann technique.

Surgeons who would like to read a full description of the Hoffmann technique will find this article helpful. Photos of patient position, incision, endoscopic entry, and intraoperative steps to release the fascia are provided. Instruments used do not touch (or barely touch) the nerve throughout the procedure.

The authors also provide tips on how to address all structures that cover and compress the ulnar nerve while avoiding complications. The most common surgical complication is damage to the cutaneous nerve and muscle branches that cross the fascia. Care must also be taken to protect the motor nerves to the muscles and blood vessels in the area.

References: Reimer Hoffmann, MD, and John Lubahn, MD. Endoscopic Cubital Tunnel Release Using the Hoffmann Technique. In The Journal of Hand Surgery. June 2013. Vol. 38A. No. 6. Pp. 1234-1239.