Courtesy: Prof Nabil Ebraheim, University of Toledo, Ohio, USA

Definition

• Common cause of lateral elbow pain caused by overuse of the extensor tendon origin.
• Primarily involves the extensor carpi radialis brevis (ECRB) tendon.
• It is a degenerative tendinosis rather than a true inflammatory condition.

Pathophysiology

• Repetitive wrist extension and forearm loading cause microtrauma at the ECRB origin.
• Histology shows:
• Disorganized collagen
• Angiofibroblastic hyperplasia
• Tendon degeneration

Risk Factors

• Repetitive gripping activities
• Manual labor
• Heavy tool use
• Racquet sports, especially tennis
• Poor technique or incorrect grip size

Clinical Features

• Pain over the lateral epicondyle
• Tenderness at the ECRB origin
• Pain during gripping activities
• Reduced grip strength
• Difficulty lifting objects
• Symptoms may interfere with sleep

Examination

Classical Test

• Pain reproduced with resisted wrist extension while the elbow is extended.

Differential Diagnosis

Radial Tunnel Syndrome

• Pain located 3–4 cm distal and anterior to the lateral epicondyle.
• Due to posterior interosseous nerve compression.

Other Causes of Lateral Elbow Pain

• Cervical radiculopathy
• Elbow arthritis
• Osteochondral lesions
• Triceps tendinitis
• Posterolateral rotatory instability

Imaging

• Usually not required for diagnosis.
• Ultrasound may show:
• Tendon thickening
• Calcification
• Increased Doppler vascularity
• MRI reserved for atypical or resistant cases.

Conservative Treatment

First-line treatment for most patients:

• Activity modification
• NSAIDs
• Counterforce brace or elbow strap
• Physiotherapy with eccentric strengthening exercises

Additional options:
• Shockwave therapy
• Acupuncture
• Iontophoresis

Injection Therapy

Corticosteroid Injection

• Provides short-term pain relief.
• Repeated injections should be avoided.

Platelet-Rich Plasma (PRP)

• Used in chronic cases.
• May stimulate tendon healing.

Dry Needling (Fenestration)

• Multiple needle passes through the diseased tendon.
• Promotes healing response.

Prognosis

• Approximately 95% of patients improve without surgery.
• Recovery may take 6–12 months.

Surgical Treatment

Indications

• Persistent symptoms despite prolonged conservative treatment.

Procedure

• Debridement of degenerative ECRB tissue.

Important Precaution

• Avoid injury to the lateral collateral ligament complex.

Complication of Surgery

• Lateral collateral ligament injury may lead to:
• Posterolateral rotatory instability (PLRI)

Outcomes

• Surgical success rate approximately 85%.

Exam Pearls

• Tennis elbow is a degenerative tendinosis, not an inflammatory condition.
• ECRB is the most commonly involved tendon.
• Pain is reproduced by resisted wrist extension.
• Radial tunnel syndrome is an important differential diagnosis.
• Most patients improve with conservative treatment.
• Surgery is reserved for resistant cases after adequate nonoperative management.