A bony growth, often called a bone spur or osteophyte, can develop in the wrist. This common condition is frequently associated with wear and tear or instability within the complex network of wrist bones and joints. While not every bony growth causes immediate problems, those that do can lead to pain and restricted movement, significantly affecting hand function. Understanding the mechanisms of their formation, where they occur, and how they are managed is the first step toward addressing this orthopedic concern.
What Exactly is a Bone Spur?
A bone spur, medically termed an osteophyte, is an abnormal, smooth bony projection that develops along the edges of a bone. These growths occur most frequently at the joints, the meeting points of two bones, or where tendons and ligaments attach to the bone surface. The formation of an osteophyte is the body’s natural but misguided attempt to repair and stabilize a joint that is experiencing damage or excessive stress.
The underlying biological reason for this growth is usually the degeneration of articular cartilage, the slick, protective tissue that cushions the ends of bones. When this cartilage wears down, causing the bones to rub together, the body responds by laying down new bone tissue. This process of new bone formation aims to increase the joint’s surface area, thereby distributing force over a wider region and limiting painful movement. However, the resulting bony lump can irritate surrounding soft tissues.
Causes and Specific Locations in the Wrist
Bone spur formation in the wrist is primarily triggered by chronic joint instability, advanced arthritis, or trauma, which disrupts the delicate alignment of the carpal bones. The most common underlying condition is post-traumatic arthritis, which develops years after an injury like a fracture of the scaphoid bone or a severe ligament tear. This initial trauma alters the normal mechanics of the joint, leading to uneven loading and subsequent cartilage breakdown.
Scapholunate Advanced Collapse (SLAC Wrist)
A specific pattern of wrist arthritis is known as Scapholunate Advanced Collapse, or SLAC wrist, which is a frequent cause of spurring. SLAC wrist results from the untreated rupture of the scapholunate ligament, causing the scaphoid bone to become unstable and abnormally positioned. The predictable progression of this condition begins with the formation of osteophytes at the articulation between the radial styloid process (a projection of the forearm bone) and the adjacent scaphoid bone.
In later stages of SLAC wrist, the spurring and cartilage loss progress to involve the entire radioscaphoid joint and the capitolunate joint. Spurs can also form on the edges of any of the small carpal bones due to general wrist osteoarthritis or inflammatory conditions like rheumatoid arthritis. The growth of these osteophytes in such confined spaces can directly impinge on the joint capsule, causing pain during wrist flexion or extension.
Identifying the Symptoms and Diagnosis
Wrist bone spurs often do not produce any noticeable symptoms and are only discovered incidentally on X-rays taken for a different reason. When symptoms do arise, they are typically related to the spur rubbing against adjacent structures or limiting the normal glide of the wrist bones. Patients may experience localized pain, which often worsens when attempting to bear weight on the hand or perform motions that require a full range of wrist movement.
The growth can also cause a palpable, hard lump under the skin, especially on the back of the wrist, which may be mistaken for a ganglion cyst. If the osteophyte is positioned near a nerve, it can cause the secondary symptom of nerve irritation, which presents as numbness, tingling, or weakness radiating into the hand and fingers. Limited range of motion and a catching or grinding sensation within the joint are also common signs, as the bony projection physically blocks smooth movement.
Diagnosis begins with a thorough clinical examination, where a physician assesses the patient’s history of pain, joint tenderness, and any limitations in movement. The definitive confirmation of a bone spur is achieved through imaging, most often a standard X-ray. X-rays effectively visualize the hard, bony tissue and can clearly demonstrate the presence, size, and location of the osteophyte. In more complex cases, or when the extent of soft tissue damage needs evaluation, a Computed Tomography (CT) scan or Magnetic Resonance Imaging (MRI) may be used to provide a detailed three-dimensional view of the wrist anatomy.
Treatment Options for Wrist Spurs
The goal of treating wrist bone spurs is to alleviate pain and restore function, with initial management focusing on conservative, non-surgical approaches. Rest and activity modification are typically the first recommendations, involving the avoidance of movements that aggravate the condition, often supported by the use of a wrist brace or splint for temporary immobilization. Over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs) can help manage pain and reduce the local inflammation surrounding the spur.
Physical therapy plays an important role in non-operative care by focusing on exercises designed to strengthen the muscles stabilizing the wrist and maintain or improve the existing range of motion. If initial measures fail to provide relief, a physician may administer a corticosteroid injection directly into the affected joint space. This potent anti-inflammatory medication can offer temporary, but often substantial, relief by reducing inflammation and swelling around the bony projection.
When conservative treatments are unsuccessful, or if the bone spur is causing significant nerve impingement or severely limiting function, surgical intervention may be considered. A common surgical procedure is an osteophyte excision, where the surgeon directly removes the offending bony growth to eliminate the source of irritation and restriction. If the underlying cause is advanced arthritis, such as late-stage SLAC wrist, the surgeon may recommend a joint-preserving procedure, like a partial wrist fusion, to stabilize the bones and eliminate the painful bone-on-bone contact.