From the Guidelines
Hypertrophy of the first metacarpophalangeal (MCP) joint is primarily caused by repetitive stress or acute trauma to the joint, with the main causes including chronic overuse, direct trauma, sports injuries, and degenerative joint disease like osteoarthritis, as supported by the 2019 American College of Rheumatology/Arthritis Foundation guideline for the management of osteoarthritis of the hand, hip, and knee 1.
Causes and Terminology
The causes of hypertrophy of the first MCP joint can be summarized as follows:
- Chronic overuse from activities requiring repetitive gripping or pinching motions
- Direct trauma such as falling on an outstretched hand
- Sports injuries, particularly skiing accidents where the thumb is forcefully abducted
- Degenerative joint disease like osteoarthritis The terminology varies based on mechanism, with "Gamekeeper's thumb" traditionally referring to chronic, repetitive injury to the ulnar collateral ligament (UCL) of the first MCP joint, and "Skier's thumb" describing an acute traumatic injury to the same structure.
Clinical Presentation and Diagnosis
Patients with hypertrophy of the first MCP joint typically present with:
- Pain
- Swelling
- Decreased range of motion
- Reduced grip strength Diagnosis is based on clinical evaluation, including history, physical examination, and imaging studies such as radiographs.
Treatment and Management
Treatment depends on severity, ranging from conservative measures to surgical intervention, as recommended by the 2019 American College of Rheumatology/Arthritis Foundation guideline for the management of osteoarthritis of the hand, hip, and knee 1, which strongly recommends exercise, weight loss, and self-efficacy and self-management programs for the management of hand osteoarthritis. Conservative measures include:
- Rest
- NSAIDs
- Splinting for 4-6 weeks Surgical intervention may be necessary for complete UCL tears or significant joint instability. Early diagnosis and appropriate management are essential to prevent chronic instability and premature osteoarthritis of this critical joint for hand function, as emphasized by the EULAR evidence-based recommendations for the diagnosis of hand osteoarthritis 1.
From the Research
Causes of Hypertrophy of the First MCP Joint
- Hypertrophy of the first metacarpophalangeal (MCP) joint can be caused by various factors, including arthritis, acromegaly, and ligamentous or capsular injuries 2, 3, 4.
- Arthritis, such as osteoarthritis, rheumatoid arthritis, and inflammatory arthritis, can lead to hypertrophy of the MCP joint due to inflammation and joint disease 2, 5.
- Acromegaly, a condition characterized by excessive growth hormone production, can cause hypertrophy of the volar plates and osteophytes, leading to locking of the MCP joints 3.
- Ligamentous or capsular injuries, such as volar plate injuries or sagittal band injuries, can also cause hypertrophy of the MCP joint 4.
Terminology Related to Hypertrophy of the First MCP Joint
- Hypertrophy of the MCP joint is often referred to as metacarpophalangeal joint arthritis or synovitis 2, 5.
- Locking of the MCP joint, which can occur due to hypertrophy of the volar plates or osteophytes, is a condition where the joint becomes stuck or unable to move normally 3, 4.
- Synovial membrane volume, which can be assessed using magnetic resonance imaging (MRI), is a quantitative measure of hypertrophic synovial membrane in the MCP joints 5.
Treatment Options for Hypertrophy of the First MCP Joint
- Treatment options for hypertrophy of the MCP joint depend on the underlying cause and may include nonsurgical interventions, such as activity modification, anti-inflammatory medications, and cortisone injections, as well as surgical interventions, such as arthroplasty or arthrodesis 2, 6.
- Surgical treatments for MCP joint hyperextension, which can occur due to hypertrophy of the joint, include volar plate advancement, tendon transfer, and arthrodesis 6.