What is the difference between lateral epicondylitis (tennis elbow) and radial tunnel syndrome?

From the Guidelines

Tennis elbow and radial tunnel syndrome are distinct conditions with different etiologies, symptoms, and treatment approaches, and proper diagnosis is crucial to prevent misdiagnosis and ineffective treatment. The primary difference between the two conditions lies in their underlying causes: tennis elbow (lateral epicondylitis) is primarily an inflammatory condition affecting the tendons that attach to the lateral epicondyle, the bony prominence on the outside of the elbow, whereas radial tunnel syndrome results from compression of the radial nerve as it passes through a narrow tunnel in the forearm.

Key Differences

• Symptom localization: Tennis elbow pain is usually localized to the lateral epicondyle, while radial tunnel syndrome pain radiates down the forearm, often accompanied by weakness, numbness, or tingling sensations, typically felt about 4-5 cm below the lateral epicondyle.
• Symptom triggers: Tennis elbow pain typically worsens with gripping activities or wrist extension, in contrast to radial tunnel syndrome, which may not have such specific triggers but can be exacerbated by activities that increase pressure on the radial nerve.
• Treatment approaches: Tennis elbow often responds to conservative measures such as rest, physical therapy, anti-inflammatory medications, and occasionally steroid injections. In contrast, radial tunnel syndrome may require specific nerve-focused treatments and sometimes surgical decompression if conservative measures fail.

Diagnostic Considerations

Given the overlap in symptoms, specific physical examination tests that differentiate between tendon pain and nerve compression are essential for healthcare providers to perform, as highlighted in studies such as 1 and 1. The use of imaging modalities like radiography, ultrasound, and MRI can also aid in diagnosis, especially when clinical findings are equivocal or when assessing for potential complications or associated injuries, as discussed in 1, 1, and 1.

Clinical Implications

Proper diagnosis and treatment are critical to prevent prolonged symptoms, reduce morbidity, and improve quality of life for patients with either condition. Misdiagnosis can lead to ineffective treatment, potentially resulting in chronic pain, decreased function, and increased healthcare utilization. Therefore, a thorough clinical evaluation, supplemented by appropriate diagnostic imaging when necessary, is essential for distinguishing between tennis elbow and radial tunnel syndrome and guiding effective management strategies.

From the Research

Differences between Lateral Epicondylitis (Tennis Elbow) and Radial Tunnel Syndrome

• Lateral epicondylitis, also known as tennis elbow, is a degenerative process of microtears in the tendon with impaired healing, primarily affecting the extensor carpi radialis brevis (ECRB) and the conjoined lateral extensor tendon 2.
• Radial tunnel syndrome, on the other hand, is a condition that results from compression of the radial nerve by the free edge of the supinator muscle or closely related structures in the vicinity of the elbow joint 3.
• The symptoms of radial tunnel syndrome can resemble those of tennis elbow, chronic wrist pain, or tenosynovitis, making diagnosis challenging 3.
• Lateral epicondylitis is characterized by pain over the origin of the extensor carpi radialis brevis and weakness in the wrist and digital extensors, whereas radial tunnel syndrome is diagnosed with lateral elbow and dorsal forearm pain that may radiate to the wrist and dorsum of the fingers 4, 5.
• The treatment approaches for the two conditions also differ, with lateral epicondylitis often managed conservatively with rest, restriction of lifting, anti-inflammatories, and local applications of ice, while radial tunnel syndrome may require surgical decompression of the radial nerve 2, 5.

Diagnostic Challenges

• Reliable objective criteria are not available to differentiate between lateral epicondylitis and radial tunnel syndrome, leading to diagnostic confusion 3.
• Clinical examination is more important than paraclinical tests, such as electrodiagnostic tests and imaging studies, in diagnosing radial tunnel syndrome 4.
• The exact site of pain and weakness of the third finger and wrist extension are valuable physical exams to diagnose radial tunnel syndrome 4.
• MRI studies may show muscle edema or atrophy along the distribution of the posterior interosseous nerve, but are not definitive in diagnosis 4.

Treatment Outcomes

• Surgical treatment for radial tunnel syndrome can diminish pain and symptoms in 67 to 93% of patients completely 4.
• Conservative treatment for lateral epicondylitis is often successful, but steroid injection or surgery may be required in some cases 5.
• Accurate diagnosis and treatment of radial tunnel syndrome can significantly improve quality of life, but validity and evidence for traditional clinical tests and definitions must be clarified 6.