Extensor tendonitis

Extensor tendonitis is an inflammatory condition affecting the tendons responsible for extending the fingers and wrist. It commonly occurs due to repetitive hand movements, overuse, or underlying systemic conditions. Early recognition and management are crucial to prevent chronic pain and loss of function.

Anatomy of the Extensor Tendons

Extensor Tendons of the Hand

The extensor tendons are responsible for extending the fingers and wrist, allowing fine motor movements and hand function. Key tendons include:

• Extensor digitorum communis: Extends the medial four fingers at the metacarpophalangeal joints.
• Extensor pollicis longus and brevis: Responsible for thumb extension at the interphalangeal and metacarpophalangeal joints.
• Extensor indicis: Specifically extends the index finger, providing independent finger movement.
• Other accessory tendons: Includes extensor digiti minimi and extensor pollicis tendons contributing to individual finger movements.

Anatomical Zones and Tendon Sheaths

The extensor tendons pass through specific anatomical compartments and sheaths that provide stability and reduce friction:

• Tendon compartments of the wrist: Six dorsal compartments house different extensor tendons and are stabilized by the extensor retinaculum.
• Sheaths and retinacula structure: Tendon sheaths are synovial-lined structures that protect tendons from friction, allowing smooth gliding during finger and wrist movements.

Definition and Pathophysiology

Definition of Extensor Tendonitis

Extensor tendonitis is the inflammation of one or more extensor tendons, typically resulting in pain, swelling, and reduced strength along the dorsal aspect of the wrist or hand. The condition can affect tendons individually or involve multiple tendons within the same compartment.

Pathophysiology

The underlying mechanisms of extensor tendonitis involve a combination of inflammatory and degenerative processes:

• Inflammatory process: Repetitive microtrauma triggers local inflammation, leading to pain, swelling, and tenderness.
• Degenerative changes: Chronic overuse can cause tendon fiber degeneration, thickening, and impaired function.
• Mechanical overload and repetitive stress: Activities involving frequent wrist extension, gripping, or typing increase mechanical stress on the tendons, exacerbating the condition.

Etiology and Risk Factors

Extensor tendonitis can result from a variety of causes, often related to repetitive strain, trauma, or systemic conditions. Understanding the etiology helps in prevention and targeted management.

• Repetitive hand and wrist activities: Activities such as typing, playing musical instruments, lifting weights, or using hand tools can overwork the extensor tendons.
• Trauma and acute injuries: Direct blows, falls, or sudden forceful movements may damage tendons, leading to inflammation.
• Systemic conditions: Diseases like rheumatoid arthritis, diabetes, and gout can predispose individuals to tendon inflammation and degeneration.
• Age-related tendon degeneration: Tendons lose elasticity and vascularity with age, making them more susceptible to overuse injuries.

Clinical Presentation

Symptoms

Patients with extensor tendonitis typically present with pain and discomfort along the dorsal wrist or hand, which may worsen with movement or activity. Common symptoms include:

• Pain and tenderness along the course of the affected tendon
• Swelling or mild warmth over the dorsal hand or wrist
• Difficulty or weakness in extending fingers or the wrist

Signs on Physical Examination

Physical examination helps localize the affected tendon and assess the severity of tendonitis:

• Localized tenderness on palpation of the tendon
• Crepitus or friction sensation during tendon movement
• Limitation of active or passive range of motion
• Swelling or erythema in the overlying skin in more severe cases

Diagnostic Evaluation

Imaging Studies

Imaging is often used to confirm the diagnosis, evaluate tendon integrity, and rule out associated pathologies:

• Ultrasound: Provides real-time visualization of tendon structure, detecting thickening, tears, and inflammation.
• MRI: Offers high-resolution images of soft tissues and can identify subtle tendon damage or tenosynovitis.
• X-ray: Generally used to exclude bony abnormalities, fractures, or joint degeneration that may contribute to tendon stress.

Laboratory Tests

Laboratory evaluation is considered when systemic disease is suspected as a contributing factor:

• Inflammatory markers such as ESR and CRP
• Rheumatoid factor or anti-CCP antibodies if autoimmune disease is suspected

Clinical Tests

Specific physical maneuvers can help localize tendon involvement:

• Resisted finger or wrist extension to reproduce pain
• Finkelstein test if overlap with De Quervain’s tenosynovitis is suspected

Management

Conservative Treatment

Most cases of extensor tendonitis respond well to non-surgical management:

• Rest and activity modification to reduce mechanical stress on the tendon
• Immobilization using splints or braces to allow tendon healing
• Nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve pain and inflammation
• Physical therapy, including stretching, strengthening exercises, and ergonomic training

Interventional Treatment

For patients not responding to conservative measures, targeted interventions may be considered:

• Corticosteroid injections to reduce local inflammation
• Platelet-rich plasma (PRP) therapy to promote tendon healing in chronic cases

Surgical Management

Surgery is reserved for refractory cases or tendon rupture:

• Debridement of degenerated tendon tissue
• Tendon repair or reconstruction if partial or complete tears are present
• Postoperative rehabilitation to restore range of motion and strength

Complications

If extensor tendonitis is left untreated or inadequately managed, several complications may arise that can impair hand function:

• Chronic pain and tendon degeneration: Persistent inflammation can lead to tendon thickening, fibrosis, and long-term discomfort.
• Tendon rupture: Severe or prolonged degeneration increases the risk of partial or complete tendon tears.
• Reduced hand function and grip strength: Pain, stiffness, and tendon damage may limit finger and wrist movements, affecting daily activities and occupational performance.

Prevention

Preventing extensor tendonitis involves strategies to minimize repetitive stress and maintain tendon health:

• Ergonomic modifications: Adjusting hand positioning, keyboard setup, or tool design to reduce strain during work or sports activities.
• Regular stretching and strengthening exercises: Maintaining flexibility and tendon strength can reduce the risk of overuse injuries.
• Avoidance of repetitive overuse: Taking breaks during repetitive tasks and gradually increasing activity intensity can help prevent tendon inflammation.

Prognosis

The prognosis of extensor tendonitis is generally favorable with timely and appropriate treatment. Early intervention with conservative measures often leads to complete recovery, while delayed treatment may result in prolonged symptoms and functional limitations.

• Factors affecting recovery: Severity of tendon inflammation, presence of degenerative changes, patient age, and adherence to therapy influence outcomes.
• Expected functional outcomes: Most patients regain full range of motion and strength, although chronic cases may experience mild residual discomfort or occasional stiffness.

References

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