Cubital Tunnel Syndrome

If your ring and small fingers have been going numb, or your hand feels clumsy when you open a jar or button a shirt, the problem may not be in your hand at all. It's often your ulnar nerve, pinched as it wraps around the inside of your elbow.

What Is Ulnar Neuropathy at the Elbow?

The ulnar nerve passes through the cubital tunnel — a narrow passageway on the inside of the elbow, right next to the bone you hit your "funny bone" on. When compressed or irritated there, you get cubital tunnel syndrome (ulnar neuropathy at the elbow). It's the second most common entrapment neuropathy in the upper extremity, right after carpal tunnel syndrome, with an estimated annual incidence of 20–30 cases per 100,000 people.

At a Glance

Cubital tunnel syndrome is pinching of the ulnar nerve at the inside of the elbow — the second most common pinched nerve in the arm after carpal tunnel
Classic symptoms are numbness and tingling in the ring and small fingers, often worse at night or when the elbow is bent
Many mild and moderate cases improve with activity changes and a simple night splint that keeps the elbow straight
When surgery is needed, options include in-situ decompression (opening the tunnel) or moving the nerve to the front of the elbow (transposition)
The sooner you're treated — before the hand muscles waste — the better your chances of full recovery

Symptoms

Early Symptoms

Numbness and tingling in the ring finger and small finger
Symptoms that wake you up at night, especially if you sleep with your elbows bent
Tingling that flares when you hold a phone to your ear, drive, or lean on an armrest
An aching or burning feeling along the inside of the elbow or forearm

As It Progresses

Constant numbness instead of coming and going
Clumsiness — dropping objects, fumbling buttons and zippers
Weak grip, especially with pinch
Visible wasting of the muscle between thumb and index finger, or hollowing between the small bones on the back of the hand
In severe cases, ring and small fingers start to curl into a "claw" position

If you see or feel muscle shrinkage, don't wait — that's when early surgery makes the biggest difference.

Diagnosis

Physical Exam

Tapping over the nerve at the elbow (positive Tinel sign), elbow flexion test (bent elbow for a minute), testing small muscle strength. Checking whether the nerve subluxes (slides out of its groove) influences which operation is best.

Nerve Conduction Studies and EMG

Measures how fast electrical signals travel along your ulnar nerve and whether the muscles it powers are getting those signals. Pinpoints where the nerve is pinched and how damaged it is.

McGowan Grade (Severity Scale)

Grade I — mild (intermittent numbness, no weakness)
Grade II — moderate (persistent numbness and mild weakness)
Grade III — severe (constant numbness with obvious muscle wasting)

Treatment

Non-Surgical Plan (for Mild and Moderate Cases — McGowan I or Early II)

Night extension splinting — keeps elbow nearly straight while sleeping; single most evidence-backed non-surgical treatment
Activity modification — no phones propped to the ear, no leaning on elbows, no sleeping with arms tucked under pillow
Padding — an elbow pad to prevent bumping or leaning on the nerve
Physical therapy — ulnar nerve gliding exercises and posture work

Give this plan a real trial — usually 6 to 12 weeks.

In-Situ Decompression (Simple Decompression)

Simplest and least invasive operation. Opens the roof of the cubital tunnel and any tight bands, but leaves the nerve exactly where it is. Recovery is fast — most people move the elbow the same day. Randomized trials show equivalent outcomes to transposition for most patients, with fewer wound complications.

Anterior Transposition (Subcutaneous or Submuscular)

Lifts the nerve out of its groove and moves it to the front of the elbow. Preferred when the nerve subluxes, when there's significant scarring from prior elbow injury or arthritis, or when in-situ decompression has already failed.

Medial Epicondylectomy

Removes part of the bony prominence on the inside of the elbow so the nerve can slide forward on its own. Less commonly used.

Outcomes

Measure	Typical Result	What to Know
McGowan grade improvement	~80–90% improve by at least 1 grade	Best results in grade I/II; grade III improves but rarely to normal
Symptom relief (any operation)	~75–85% of patients	Similar between in-situ and transposition in randomized trials
Long-term reoperation — in-situ decompression	~20–25%	Most revisions happen within first 3 years
Long-term reoperation — subcutaneous transposition	~10–12%	Lower revision rate in matched cohorts
Time to meaningful recovery	Weeks to 12 months	Tingling first, strength last; severe cases take longest

References

Caliandro P, et al. Treatment for ulnar neuropathy at the elbow. Cochrane Database Syst Rev. 2016;11(11):CD006839. PMID: 27845501
Said J, et al. Ulnar nerve in situ decompression versus transposition for idiopathic cubital tunnel syndrome: updated meta-analysis. J Hand Microsurg. 2019;11(1):18-27. PMID: 30911208
Shah CM, et al. Outcomes of rigid night splinting and activity modification in the treatment of cubital tunnel syndrome. J Hand Surg Am. 2013;38(6):1125-1130. PMID: 23647638
Hutchinson DT, et al. Long-term reoperation rate for cubital tunnel syndrome: subcutaneous transposition versus in situ decompression. Hand (NY). 2021;16(4):447-452. PMID: 31517521
Gervasio O, et al. Simple decompression versus anterior submuscular transposition of the ulnar nerve in severe cubital tunnel syndrome. Neurosurgery. 2005;56(1):108-117. PMID: 15617592

Our Specialists

P.B. Raksin, MD

Neurosurgery

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