Let’s review this condition first to better understand what is going on and what can be done about it. 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.
As you described, 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. Symptoms that are made worse with sleeping position may be eliminated by the use of a night splint. If you have not tried this approach, it may be worth asking your surgeon about it. Usually, a hand therapist measures and fits you for this type of device.
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. You may have had this procedure done.
If symptoms are improved but not eliminated after the first surgery, there are other procedures that might help. For example, the surgeon can move (transpose) the nerve to a new location (away from the structures pressing on it). Another option is to perform a medial epicondylectomy (removal of the bone along the inside of the elbow).
There is also a procedure known as 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 advantage of this surgical approach is that it enables the surgeon to release other areas where the fascial bands (connective tissue) underneath the muscles are compressing or entrapping the nerve. These fascial bands may have been missed with the first procedure.