Arthritis in the hand is a highly prevalent condition, with hand osteoarthritis alone affecting a significant portion of the adult population, particularly as they age. This chronic joint inflammation, stemming from conditions like osteoarthritis or rheumatoid arthritis, often leads to a painful loss of motion and the progressive bending or misalignment of the fingers. The resulting stiffness and deformity can severely limit the ability to perform simple daily tasks, such as gripping objects or buttoning a shirt. Managing and correcting these bent fingers requires a comprehensive approach, starting with non-invasive therapies and potentially progressing to surgical interventions.
Understanding the Deformities Caused by Arthritis
The bending of arthritic fingers results from a complex interplay of joint destruction and tendon imbalance. In both osteoarthritis and rheumatoid arthritis, the cartilage cushioning the joints erodes, which leads to bone-on-bone friction and the formation of bone spurs, gradually altering joint shape. Joint destruction can affect the delicate balance of the extensor tendons, which are responsible for straightening the fingers.
Two distinct and common patterns of bending occur in the fingers. The first is the Swan Neck deformity, where the middle joint of the finger, the proximal interphalangeal (PIP) joint, is hyperextended, while the fingertip joint, the distal interphalangeal (DIP) joint, is flexed or bent inward. This posture is often linked to rheumatoid arthritis causing laxity in the ligaments on the palm side of the joint, which allows the middle joint to bow backward.
The second common pattern is the Boutonnière deformity, which presents as a flexion of the middle (PIP) joint and an over-straightening (hyperextension) of the fingertip (DIP) joint. This bending is caused by damage to the central slip of the extensor tendon over the PIP joint. Identifying which specific joint is bent and in which direction is important, as the correct approach to straightening the finger depends entirely on the type of deformity present.
Targeted Exercises and Splinting
For individuals experiencing early-stage bending and stiffness, maintaining mobility through physical therapy and specialized exercises is a primary strategy. These targeted movements are designed to promote tendon gliding, ensuring the flexor and extensor tendons slide smoothly past one another and preventing further shortening or adhesion.
A core set of movements involves a sequence of hand postures known as tendon gliding exercises. These include forming a hook fist, a straight fist, and a full fist, all followed by returning to a fully straight hand. Performing these motions slowly and deliberately helps to move the three joints of the fingers through their maximum range of motion.
Another valuable technique is the use of blocking exercises, which isolate movement to a single joint. For instance, a finger can be placed flat on a table, and the individual attempts to bend only the fingertip joint while keeping the middle joint flat, or vice versa, by using the opposite hand to stabilize the joint. These exercises directly target the specific joint affected by stiffness or contracture, helping to counteract the mechanical forces driving the bend. Applying moist heat before an exercise session can help relax the joints and surrounding soft tissues, increasing the effectiveness of the movements.
Splinting provides mechanical support to help hold the bent finger in a straighter, more functional position and prevent the progression of deformities. Ring splints, which often resemble jewelry and are made from materials like silver or plastic, are commonly used for this purpose. Specific splint designs exist for each common deformity: swan-neck splints prevent the backward bowing of the PIP joint, and boutonnière splints assist in straightening a middle joint that is stuck in a flexed position. These devices stabilize the joint within its normal range of motion.
Pharmaceutical and Injection Therapies
While exercises and splinting address the mechanical aspect of finger bending, pharmaceutical treatments target the underlying inflammation and pain that accelerate joint damage. Nonsteroidal anti-inflammatory drugs (NSAIDs) are often the first line of defense to reduce pain and swelling in joints affected by osteoarthritis. For inflammatory types of arthritis, such as rheumatoid arthritis, disease-modifying antirheumatic drugs (DMARDs) and biologic agents are used to slow the disease’s progression by suppressing the immune system’s attack on the joints.
Corticosteroid injections offer a direct and potent method of managing localized joint inflammation, which is a significant driver of deformity. These injections deliver a strong anti-inflammatory medication directly into the affected joint space. The goal of the injection is to reduce swelling and pain, which can temporarily improve a finger’s mobility and allow for greater participation in physical therapy.
The procedure is commonly performed on the distal interphalangeal (DIP) joints, which are frequently affected by osteoarthritis. Although corticosteroid injections can offer temporary relief lasting several months, they are not a long-term solution for straightening the finger. Repeated injections into the same joint are limited due to the risk of weakening surrounding tendons and ligaments.
When Surgery Becomes Necessary
When non-surgical treatments fail to manage pain, halt the progression of deformity, or restore acceptable function, surgical intervention may be considered. Surgery is generally reserved for advanced cases where the finger’s alignment is severely compromised and limits the individual’s quality of life. The specific procedure chosen depends on the joint affected and the desired outcome for the finger’s mobility.
One common definitive procedure is joint fusion, or arthrodesis, which involves surgically joining the two bones of the joint together. This approach permanently stabilizes the joint, corrects the bent position, and eliminates pain. Arthrodesis is frequently utilized for the smaller DIP joints at the fingertip, where stability is prioritized over movement, resulting in a straight finger that cannot bend at that joint.
The alternative is joint replacement, or arthroplasty, which involves removing the damaged joint surfaces and replacing them with an artificial implant, often made of silicone, plastic, or metal. Joint replacement is performed to restore both alignment and some degree of motion, especially in the larger knuckle joints (MCP) and the middle finger joints (PIP). While arthroplasty aims for a straight and partially mobile finger, the long-term wear of the artificial joint may necessitate further surgery in the future.