Trigger finger and Dupuytren’s contracture both affect the mobility of the fingers and the palm, but they are distinct conditions with different underlying biological causes. Although they sometimes present with similar symptoms of a bent or stiff finger, they involve separate anatomical structures within the hand. Understanding these differences is important because their progression, prognosis, and treatment methods are entirely separate. The core distinction lies in which part of the hand mechanism is compromised, dictating the required therapeutic approach.
Understanding Trigger Finger
Trigger finger, medically known as stenosing tenosynovitis, involves a mechanical problem with the finger’s flexor tendon system. This condition occurs when the smooth gliding of the tendon is impaired as it passes through its protective sheath and the surrounding annular pulleys. The pulleys are fibrous rings that hold the tendon close to the bone. The pathology arises when the flexor tendon or the A1 pulley at the base of the finger becomes inflamed and thickened.
This mismatch creates a tight squeeze, making it difficult for the tendon to slide freely when the finger is bent or straightened. As the condition progresses, a small nodule may form on the tendon, which then catches at the entrance of the pulley. This catching produces the characteristic popping or snapping sensation, often most noticeable upon waking. The affected finger may temporarily lock in a bent position, sometimes requiring the use of the other hand to manually straighten it.
Pain and tenderness are typically felt at the base of the digit, where the tendon sheath is constricted. Trigger finger is frequently associated with repetitive forceful hand movements. It is also more common in people with conditions like diabetes or rheumatoid arthritis.
Understanding Dupuytren’s Contracture
Dupuytren’s contracture is a progressive hand deformity caused by the abnormal thickening and shortening of the palmar fascia. The palmar fascia is a dense layer of fibrous connective tissue located directly beneath the skin of the palm. This process begins with the formation of firm nodules under the skin, usually near the base of the ring and little fingers.
Over time, these nodules mature into thick, rope-like cords that extend from the palm into the fingers. These cords are the contracted palmar fascia, which pulls the affected fingers inward toward the palm in a fixed, bent position. The inability to fully straighten the fingers is the defining feature of the contracture.
This condition is typically slow-progressing, developing over months or years, and is often painless in its early stages. Dupuytren’s contracture has a strong genetic component, with the highest risk found in men over 50 of Northern European ancestry. It is also associated with certain medical conditions, including diabetes, epilepsy, and alcohol use.
Distinguishing Causes and Treatment Approaches
The primary distinction between the two conditions is the specific tissue involved, which dictates the necessary treatment. Trigger finger is a mechanical issue involving the flexor tendon and its pulley system, causing a gliding obstruction. Dupuytren’s contracture, conversely, is a fibrotic disorder where the palmar fascia tissue thickens and shortens.
Trigger finger often presents acutely with pain and a sudden locking sensation. Treatment often begins conservatively with splinting, rest, or a corticosteroid injection to reduce local inflammation within the tendon sheath. If non-surgical options fail, a minor surgical release of the A1 pulley is performed to create more space for the tendon to move.
Dupuytren’s contracture is typically a gradually worsening contracture that is often painless until a severe contracture develops. Because the issue lies in the contracted fascia, non-surgical treatments focus on breaking down or dissolving the fibrous cord. These treatments include needle aponeurotomy, which uses a needle to divide the cord, or injections of an enzyme called collagenase to dissolve the tissue. More advanced cases may require a fasciectomy, which is the surgical removal of the diseased palmar fascia to release the fingers.