Cubital tunnel syndrome, also called ulnar nerve entrapment, is caused by compression or stretching of the ulnar nerve as it passes through the cubital tunnel just behind the inside edge of the elbow.

The ulnar nerve, also known as the “funny bone,” is part of a network of nerves that originates in the spine and runs from the collarbone, along the inside of the arm, through the wrist, and into the little-finger side of the hand. The most common areas of entrapment are beneath the collarbone, in the cubital tunnel in the elbow, or in the Guyon’s canal in the wrist.

Cubital tunnel syndrome has several causes, including:

• A blow to the cubital tunnel
• Bone spurs
• Shifting of the ulnar nerve
• Narrowing of the tunnel as a result of osteoarthritis or rheumatoid arthritis
• Frequent bending and straightening of the elbow, such as when pulling levers, reaching or lifting
• Constant direct pressure on the elbow
• Leaning on the elbow repeatedly

Cubital tunnel syndrome may also occur after a displaced fracture of the humerus or ulna.

Individuals with cubital tunnel syndrome often experience numbness, tingling or pain on the outside of the hand and the ring and little fingers. Other symptoms include weakness when gripping objects and difficulty with tasks requiring fine motor control. Symptoms are often worse at night.

Evaluation by a hand subspecialist at Lancaster Orthopedic Group is important for pinpointing the exact spot that is causing your symptoms. Special tests may be done to determine whether the ulnar nerve and forearm muscles are working properly.

The physician will typically recommend that you stop the activities that are causing the symptoms. Ice or cold therapy and anti-inflammatory medications may help control the pain and inflammation. In severe or persistent cases, surgery may be recommended to stop damage to the ulnar nerve.