Ulnar Nerve Entrapment

Introduction

Ulnar nerve

Ulnar nerve entrapment occurs when the ulnar nerve is compressed. This typically occurs at two main sites: the elbow and the wrist. Ulnar nerve entrapment at the elbow is usually at the cubital tunnel (Cubital Tunnel Syndrome). Ulnar nerve neuropathy at the elbow is the second most common entrapment neuropathy (the first most common is the median nerve at the wrist).[1] Ulnar nerve neuropathy less commonly occurs at Guyon’s canal in the wrist (Guyon’s canal syndrome/ulnar tunnel syndrome).

Causes

Ulnar nerve entrapment at the elbow (Cubital Tunnel Syndrome) and wrist (Guyon's Canal Syndrome) occur due to repetitive compression, from leaning on the elbows or wrists (cyclist's palsy) and prolonged elbow flexion. It can also occur from trauma, swelling, fractures, and vascular and bony pathologies/abnormalities.

Guyon’s canal syndrome occurs when the ulnar nerve becomes entrapped between the hook of the hamate and the transverse carpal ligament.  Guyon’s canal syndrome is considered an overuse injury which is commonly caused by direct pressure on a handlebar (ie. bicycle handlebar, weight lifting, construction equipment) and therefore, is sometimes referred to as “handlebar palsy”. It can also result from excessive gripping, twisting, or repeated wrist and hand motions. Also, entrapment may develop if the hand is flexed and ulnar deviated for prolonged periods of time.

The incidence of trauma leading to ulnar nerve compression is unknown; however ulnar neuropathy has been documented after distal humeral fractures and in up to 10% of elbow dislocations, and may also develop from any complex elbow or wrist trauma.[2]

Clinical Presentation[3][4][5][6][7][8]

Symptoms of ulnar nerve entrapment include tingling in fingers 4 and 5, weak grip strength, pain and sensitivity on the ulnar side of the forearm, wrist and hand, muscle atrophy, clawing of digits 4 and 5 (sign of benediction).

A. Cubital Tunnel Syndrome can present in different grades of severity:

  1. Grade I: Mild symptoms
    • Intermittent paresthesia
    • Minor hypoesthesia of the dorsal and palmar surfaces of the fifth and medial aspect of fourth digits
    • No motor changes
  2. Grade II: Moderate and persistent symptoms
    • Paresthesia
    • Hypoesthesia of the dorsal and palmar surfaces of the fifth and medial aspect of fourth digits
    • Mild weakness of ulnar innervated muscles
    • Early signs of muscular atrophy
  3. Grade III: Severe symptoms
    • Paresthesia
    • Obvious loss of sensation of the dorsal and palmar surfaces of the fifth and medial aspect of fourth digits.
    • Significant functional and motor impairment
    • uscle atrophy of the hand intrinsics
    • Possible digital clawing of fourth and fifth digits (Sign of Benediction)

B. Guyon's Canal Syndrome symptoms include:

  1. Muscular atrophy - Primarily the hypothenar muscles and interossei with muscle sparing of the thenar group:
    • weakened finger abduction and adduction (interossei)
    • weakened thumb adductor (adductor pollicis)
  2. Sensory loss and pain -
    • May involve the palmar surface of the fifth digit and medial aspect of the fourth digit.
    • Dorsum of medial aspect of the fourth finger and the dorsum of the fifth finger don’t have sensory loss.
  3. Ulnar Claw may present (sign of Benediction)

Physical Therapy Examination[9][10]

Click here for Cubital Tunnel Syndrome.

Guyon's Canal Syndrome:

  • Rule out other diagnoses which could refer to the elbow (listed below)
  • ROM of the wrist and digits
  • MMT of ulnar nerve muscles innervated distal to Guyon’s Canal
  • Sensory exam of the ulnar nerve cutaneous distributiondistal to Guyon’s Canal
  • Muscle wasting of intrinsic hand muscles

Special Tests:

  • Card test
  • Froment’s Sign
  • Tinnel’s sign at Guyon’s canal
  • Ulnar neurodynamic test (ULTT3) may increase the patient’s symptoms

Diagnostic Tests for Ulnar Nerve Entrapment:

  • Imaging for OA, bone spurs, or bone cysts
  • Nerve Conduction Studies (EMG)
  • If fracture/dislocation is suspected, plain film x-ray

Outcome Measures[11]

  • Disabilities of the Arm, Shoulder, and Hand - A 30 item questionnaire, targeted towards measuring the physical function and symptoms of patient
  • Patient Specific Functional Scale (PSFS) - A questionnaire that is utilized to quantify activity limitations and measure functional outcomes of patients
  • DASH Outcome Measure  - A questionnaire that measures a patient’s functional ability and severity of their symptoms
  • Upper Extremity Functional Index (UEFI)  - A questionnaire of 20 items regarding severity of difficulty performing activities throughout the day

Physical Therapy Management / Interventions

  • Impairment-based approach can be used to address deficits in strength, ROM, and the attainment of functional goals
  • The source of the pain should be treated in conjunction with the impairments.
  • Following treatment, reassess the functional task that produced pain to determine effective treatment outcome
  • Administer a home exercise program that aims to treat the same impairments and function tasks


In a study conducted by Svernlov and colleagues, three treatments were compared for individuals with cubital tunnel syndrome.(Level of Evidence 1B)[2] All three groups had positive outcomes, with the control group improving just as much as the intervention groups.(Level of Evidence 1B)[2]   

  1. Splint group protocol (Level of Evidence 1B)[2]  - An elbow brace was worn every night for a period of three months and the brace prevented elbow flexion beyond 45 degrees. 
  2. Nerve gliding protocol(Level of Evidence 1B)[2]  - Patients were instructed to complete nerve gliding exercises two times per day in six different positions and hold them for 30 seconds for three repetitions with a 1 minute break in between each repetition. Patients were instructed to complete these exercises until the next visit, which occurred 1-2 weeks later. The frequency of the exercises were increased to three times per day, holding the exercise for one minute each day for a period of three months if there were no symptoms at the next visit.
  3. Control group protocol(Level of Evidence 1B)[2] - The control group only received education

According to a case report by Coppieters and colleagues, joint mobilizations of the elbow, thoracic spine and rib thrust manipulations, and ulnar nerve sliding/tension techniques for six sessions were associated with improvements of decreased elbow pain and considerable improvement scores on a neck questionnaire up to a ten month follow-up.(Level of Evidence 3B)[12] The patient reported a history of symptoms for two months prior to starting physical therapy.(Level of Evidence 3B)[12] The protocol used in this study can be seen by accessing the link in the case study section below.

Guyon’s Canal Syndrome and other ulnar nerve sites:

Differential Diagnosis[4]

The cervical spine and shoulder regions should be examined to rule out diagnoses that can refer to the elbow.
There are numerous differential diagnoses for ulnar nerve entrapment such as:

Highlights for Physical Therapy[13][2]

  • Special tests that are utilized in the diagnosis of ulnar nerve entrapment have extremely high sensitivity of .98 and above and therefore are extremely useful in ruling in diagnosis.
  • Conservative treatment is effective about 50% of the time, while surgical intervention is effective 60-95% of the time
  • Conservative management has been proven effective when incorporating splinting and manual therapy including neural glides and joint mobilizations
  • Patient’s seeking conservative treatment earlier rather than waiting have a thirty percent greater chance of avoiding surgery

References

  1. Lauretti L, D'Alessandris QG, De Simone C, Sop FY, Remore LM, Izzo A, Fernandez E. Ulnar nerve entrapment at the elbow. A surgical series and a systematic review of the literature. Journal of Clinical Neuroscience. 2017 Dec 1;46:99-108.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Svernlov B, Larsson M, Rehn K, Adolfsson L. Conservative treatment of the cubital tunnel syndrome. J Hand Surg Eur Vol. 2009;34(2):201-207.Level of evidence: 1B
  3. Neuropathy of Ulnar Nerve (Entrapment). MD Guidelines. http://www.mdguidelines.com/neuropathy-of-ulnar-nerve-entrapment/differential-diagnosis. Accessed March 15, 2011.
  4. 4.0 4.1 Ulnar Neuropathy. Emedicine from WebMD. http://emedicine.medscape.com/article/1141515-overview. Updated June 10, 2010. Accessed March 15, 2011.
  5. Palmer BA, Hughes TB. Cubital Tunnel Syndrome. J Hand Surg. 2010: 35 (1): 153-163.
  6. Nerve Entrapment Syndromes. Emedicine from WebMD. www.emedicine.medscape.com/article/249784-overview Updated July 31, 2009. Accessed March 15, 2011.
  7. Ulnar Nerve Entrapment. American Academy of Orthopaedic Surgeons. http://orthoinfo.aaos.org/topic.cfm?topic=a00069. Updated October 2007. Accessed March 15, 2011.
  8. Shin R, Ring D. The Ulnar Nerve in Elbow Trauma. J. Bone Jt. Surg. (Am.). 2007: 89: 1108-1116.
  9. Ulnar Nerve Entrapment. Wikipedia. 2011. Available at: http://en.wikipedia.org/wiki/Ulnar_nerve_entrapment. Accessed March 17, 2011.
  10. Ulnar Nerve Entrapment. American Academy of Orthopaedic Surgeons. 2007. Available at: http://orthoinfo.aaos.org/topic.cfm?topic=a00069. Accessed March 17, 2011.
  11. ProQolid. http://www.proqolid.org/proqolid_1/generic. Updated 2011. Accessed March 15, 2011.
  12. 12.0 12.1 Coppieters MW, Bartholomeeusen KE, Stappaerts KH. Incorporating nerve0gliding techniques in the conservative management of cubital tunnel. J Manipulative Physiol Ther. 2004;27(9):560-568.Level of evidence: 3B
  13. Spinner RJ. Outcomes for Peripheral Nerve Entrapment. Clin Neurosurg. 2006; 53: 285-294.