Cubital Tunnel Syndrome

The anatomy

Cubital tunnel syndrome is the second most common upper limb nerve compression. The most common being carpal tunnel syndrome at the wrist (Willem et al, 2013). These conditions are called ‘entrapment or compressive neuropathies’.

An entrapment neuropathy occurs at an anatomical ‘pinch point’ where a nerve is subjected to adverse compressive pressure. The literature indicates that direct compression of the nerve results in an ischaemic reaction i.e. a mild restriction to the blood supply to the nerve. This ischaemic reaction causes the nerve to become inflamed and painful (Apfel et al, 2006).

Common Symptoms of Cubital Tunnel Syndrome include:

1. Aching and occasional sharp pains on the inside of the elbow, forearm, wrist and hand- especially with elbow bent
2. Pins and needles and numbness especially in the hand especially 4th (ring) and 5th (little) fingers – often worse at night or first thing in the morning
3. Weakness in the hand especially the 4th (ring) and 5th (little) fingers.
4. Clumsiness and weak grip
5. In severe cases you can develop a claw-like deformity of the hand (this is rare)

Why is it called Cubital Tunnel syndrome?

The ulnar nerve is one of the three main nerves that pass down the arm. It originates at the base of the neck and runs down the inner aspect of the upper arm, forearm and wrist terminating at the 4th (ring) and 5th (little) fingers.

At the level of the elbow, the ulnar nerve sits within a bony tunnel located at the medial (inner) aspect of the elbow joint (just behind the bony bit of the elbow on the inside). The nerve sits between the medial epicondyle (bony bit on the inside of your elbow) and olecranon (bony point of the elbow). This tunnel is called the cubital tunnel (see image below).

Cubital tunnel syndrome occurs when the ulnar nerve, sitting in the tunnel, is subjected to prolonged periods of increased pressure. This results in the nerve becoming swollen before and after the site of compression (like standing on a hose pipe).

Many of us have actually experienced an acute transient episode of ulnar nerve irritation before! If you ever hit your ‘funny bone’ you will have experienced pain shooting down the inner aspect of your forearm, wrist and fingers and may have also felt pins and needles in the 4th and 5th fingers. The “funny bone” in the elbow is actually the ulnar nerve, a nerve that crosses the elbow. This can give you an idea of how sensitive nerves are and how uncomfortable this condition can be.

Nerves are responsible for relaying sensory information concerning temperature, texture and sensation (both light touch and pain) and motor information to and from the muscles to the brain to contract and relax muscles.
Nerve tissue is highly susceptible to injury and are responsible for a variety of symptoms including dull/achy and sharp pain, weakness, pins and needles and numbness.
Clients with cubital tunnel syndrome often experience sharp and/or aching pain primarily located on the inner aspect of the elbow. Pain can radiate further down the forearm and is often described as pins and needles and a reduction in sensation. Patient’s also often describe muscle weakness and a sensation of coldness or ‘fizzing’ within the forearm (Apfel et al, 2006).

What causes Cubital Tunnel syndrome?

There are many causes of cubital tunnel syndrome and in some cases the exact cause is not known. To ensure we choose the correct treatment option for you it is essential we try and establish why it has occurred in the first place.

Cubital tunnel can occur due to:

• Trauma – a fall onto the elbow
• Repetitive compression – leaning on the elbow for hours when at work
• Arthritis – you can develop bony spurs (known as osteophytes)
• Previous fractures/’breaks’ or dislocations at the elbow
• Accessory muscles for example an extra muscle bely of your triceps muscle
• Subluxation/slipping of the nerve over the bone (medial epicondyle) – more below
• Swelling or cyst of the elbow joint
• Repetitive or prolonged activities that require bending of the elbow such as bench press in the gym
• Prior injuries to the nerve

One of the most common reasons we see for cubital tunnel syndrome in the clinic is subluxation or dislocation of the nerve. Subluxation is when the nerve slips over the bone but returns into the groove. This normally occurs with bending of the elbow. Dislocation is when the nerve slips over the bone and stays out of the bony tunnel. This normally occurs with bending of the elbow. The classic presentation is a gym goer who regularly pushes heavy weights on a bench press.

You can be more prone to this condition, in fact any nerve entrapment, if you have other pre-existing medical conditions. These risk factors include:

• diabetes (particularly if poorly controlled)
• pregnancy
• obesity
• arthritis
• hypothyroidism

How is Cubital Tunnel Syndrome diagnosed?

Diagnosis of cubital tunnel syndrome can be made using a combination of clinical tests, nerve conduction studies and diagnostic ultrasound imaging.

At Complete we can diagnose this condition with clinical examination and diagnostic ultrasound in your session. We do not charge extra for the diagnostic ultrasound.

A recent study by Terlemez (et al. 2018) concluded that diagnostic ultrasound imaging is more accurate at diagnosing cubital tunnel syndrome than nerve conduction tests. Diagnostic ultrasound scan also has the additional benefits of being painless (unlike nerve conduction studies) and is a dynamic examination so it can confirm if the nerve subluxes or dislocates. Previous studies have also observed accuracy rates of nerve conduction tests to range between 37% and 86% in comparison to diagnostic ultrasound accuracy rates of 98%.
Nerve conduction studies should be reserved for severe cases where you have significant muscle weakness and/or wasting and if conservative treatments and/or a steroid injection have not helped.

How can you reduce your pain from cubital tunnel syndrome?

In most cases, cubital tunnel syndrome can be managed conservatively with simple advice with or without an injection. Surgery is reserved for those not improving who have significant compression and associated muscle weakness, muscle wasting and functional deficits.

Mild to moderate cases of cubital tunnel syndrome often respond to physiotherapy. Here are a few tips to try yourselves:

• Ensure you are not leaning on the elbow whist working at your desk – this may be on the desk itself or on the arms of the chair
• If you are a manual worker wear a neoprene support or an elbow pad if you often have to lean on your elbow
• If the pain is particularly bad at night or first thing in the morning then consider wearing an elbow splint to stop the elbow bending at night

In cases where splinting doesn’t help or nerve compression is more severe, about 85% of patients respond to some form of surgery to release pressure on the ulnar nerve. These include surgeries that:

• Result in simple decompression of the ulnar nerve
• Shift the nerve to the front of the elbow
• Move the nerve under a layer of fat, under the muscle, or within the muscle
• Trim the bump of the inner portion of the elbow — the medial epicondyle — under which the ulnar nerve passes

What if your symptoms are not improving?

In some cases cubital tunnel syndrome can be a challenging condition to treat especially if it has been there for many months or even years. A systematic review concluded that not all cases improve with conservative treatment options which included activity modification and the use of an elbow splint at night (Ho et al, 2018).

Ultrasound-guided injections

Ultrasound-guided steroid injections have been used for many decades for this condition and have been shown to be accurate, safe and effective. Guided steroid injections can significantly reduce the pain and symptoms associated with cubital tunnel syndrome (Choi et al, 2015). At Complete an ultrasound scan is used to safely and effectively to guide the injection into the cubital tunnel and bathe the ulnar nerve with a combination of local anaesthetic and corticosteroid. Steroid (also known as corticosteroid) injections, are a strong anti-inflammatory medication which is commonly used to reduce pain and inflammation.

During your initial assessment, your clinician will take a full history of your problem and undertake a series of clinical tests including a diagnostic ultrasound scan. Once a formal diagnosis of cubital tunnel syndrome has been made, if appropriate, you may be offered an ultrasound-guided steroid injection. This will be carried out in the same session as your initial assessment. There is no requirement for a referral from your GP.

Surgery

In rare cases, when conservative management or injection therapy has not been successful, a surgical approach to treatment may be offered. This option should not be taken lightly and only considered as a last resort. A systematic review and meta-analysis revealed that surgical intervention for cubital tunnel syndrome is no more effective than surgical management (Willem et al, 2013). This option can be discussed further with your clinician if required.

If you undergo surgery for cubital tunnel syndrome, recovery may involve restrictions on lifting and elbow movement. You will require a course of physiotherapy to restore full range of movement and function. Although numbness and tingling may or may not quickly improve, recovery of hand and wrist strength may take several months.

All clinicians at Complete are dual trained, highly specialised physiotherapists and musculoskeletal sonographers experienced in the diagnoses of all elbow conditions including cubital tunnel syndrome. We provide a ‘one stop’ clinic which means you receive an assessment, a diagnostic ultrasound and an ultrasound guided injection if required.

If you would like further information or to book an appointment please contact us on 0207 4823875 or email injections@complete-physio.co.uk.

Other elbow conditions:

• Tennis Elbow
• Golfers Elbow
• Olecranon Bursitis
• Distal Biceps