Basal Thumb Arthritis

As we delve into the complexities of basal thumb arthritis, it is crucial to understand the multifaceted nature of this condition, which affects the carpometacarpal (CMC) joint located at the base of the thumb. Basal thumb arthritis, also known as thumb CMC arthritis, is a prevalent form of osteoarthritis that predominantly impacts individuals over 40 years of age, with a higher incidence in females.

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Symptoms of Basal Thumb Arthritis

The symptoms of basal thumb arthritis can be insidious, often beginning with mild discomfort and progressing to more significant functional impairments. Recognizing these symptoms early can lead to more effective management and improved quality of life.

Pain and Swelling

One of the hallmark symptoms is pain at the base of the thumb, especially when gripping or pinching objects. This pain is often exacerbated by activities that require significant thumb use, such as opening jars or turning doorknobs. Swelling around the affected joint is also common, contributing to the discomfort experienced by sufferers.

Reduced Range of Motion

As the condition advances, individuals may notice a decrease in the range of motion of the thumb. This limitation can significantly impair the ability to perform everyday tasks that require fine motor skills, leading to frustration and decreased independence.

Joint Stiffness and Weakness

Joint stiffness, mainly after periods of inactivity, is another symptom frequently reported by individuals with basal thumb arthritis. This stiffness is often accompanied by a sensation of weakness in the thumb, making it challenging to perform tasks that require strength and dexterity.

Visible Deformity

In severe cases, the thumb may develop a noticeable deformity, often referred to as "subluxation," where the thumb appears to slip out of its normal position. This deformity not only affects the aesthetic appearance of the hand but also contributes to functional limitations.

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Causes of Basal Thumb Arthritis

Understanding the underlying causes of basal thumb arthritis is essential for effective management and prevention. While the exact aetiology is multifactorial, several risk factors have been identified.

Age and Gender

Age is a significant risk factor, with the likelihood of developing basal thumb arthritis increasing with advancing age. Women are disproportionately affected, possibly due to hormonal influences and differences in joint anatomy.

Genetic Predisposition

Genetics also play a role, with a family history of arthritis increasing the risk. Specific genetic markers associated with cartilage degradation and inflammation have been identified, suggesting a hereditary component to the disease.

Occupational and Lifestyle Factors

Repetitive use of the thumb in occupational or recreational activities can contribute to the development of basal thumb arthritis. Individuals engaged in activities that place excessive stress on the thumb joint, such as manual labour or certain sports, are at a higher risk.

Previous Injuries

Previous injuries to the thumb joint, including fractures or sprains, can predispose individuals to arthritis later in life. These injuries may disrupt the normal biomechanics of the joint, accelerating degenerative changes.

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Diagnosis of Basal Thumb Arthritis

Accurate diagnosis is critical for effective management of basal thumb arthritis. A thorough clinical evaluation, combined with diagnostic imaging, is typically employed to confirm the diagnosis.

Clinical Evaluation

A comprehensive clinical evaluation involves a detailed history and physical examination. The clinician will assess for tenderness, swelling, and deformity at the base of the thumb, as well as evaluate the range of motion and grip strength.

Imaging Techniques

Radiographic imaging, particularly X-rays, is instrumental in diagnosing basal thumb arthritis. X-rays can reveal joint space narrowing, osteophyte formation, and subluxation, which are indicative of arthritis. In some cases, advanced imaging modalities such as MRI may be utilized to assess soft tissue involvement.

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Management of Basal Thumb Arthritis

Effective management of basal thumb arthritis involves a combination of conservative and, in some cases, surgical interventions. The goal is to alleviate pain, improve function, and enhance the quality of life.

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Conservative Treatments

Splinting and Bracing

Splinting or bracing can provide support and reduce stress on the affected joint, thereby alleviating pain and improving function. Custom orthotics are often recommended to ensure optimal fit and support.

Pharmacotherapy

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly prescribed to manage pain and inflammation. In cases of severe pain, corticosteroid injections may be administered directly into the joint for rapid relief.

Physical Therapy

Physical therapy plays a pivotal role in the management of basal thumb arthritis. A tailored exercise program focusing on strengthening the muscles around the thumb and improving the range of motion can significantly enhance function and reduce pain. Techniques such as heat and cold therapy may also be beneficial.

Surgical Interventions

For individuals with severe, refractory symptoms that do not respond to conservative measures, surgical intervention may be considered. Several surgical options are available, including:

Trapeziectomy

This involves the removal of the trapezium bone at the base of the thumb, which can alleviate pain and improve function.

Ligament Reconstruction and Tendon Interposition (LRTI)

LRTI is a more complex procedure that involves reconstructing the joint using a tendon from the forearm, providing stability and reducing pain.

Joint Fusion

In some cases, fusing the bones of the thumb joint may be recommended to eliminate pain, although this results in loss of joint mobility.