Macrodactyly of Fingers: An overview

Introduction:

Macrodactyly refers to the abnormal growth of one or more digits or toes in hands and feet. Macrodactyly of fingers is often associated with other conditions or syndromes, or it may also occur in an isolated form. Other names that were used for this condition include Macrodactylia fibro-lipomatosis, Megalodactyly, local gigantism, Dactylomegaly, hamartoma, digital gigantism, and macro dystrophia lipomatosis. Even though it is believed to be caused by genetic defects, this condition cannot be passed down from the parents. This article will discuss the macrodactyly of fingers, its causes, classification, diagnosis, and treatment.

What Is Macrodactyly?

Macrodactyly of fingers is an uncommon condition characterized by abnormal growth of fingers than their normal size that is caused due to excessive growth of the underlying anatomical structures or the accumulation of any abnormal substances. This condition is primarily present at birth. It commonly occurs in one hand of the patient and mainly affects multiple fingers. They are often seen in association with other limb disorders, such as syndactyly (a condition with one or more fingers fused) and polydactyly (a congenital anomaly with a presence of an extra finger during birth). The presence of enlarged fingers can affect the quality of life in the affected patients.

What Causes the Macrodactyly of Fingers?

Like any other limb disorder, the underlying cause of macrodactyly is poorly understood. It is not caused by anything that happened to the pregnant mother of the affected child. Even though it is a congenital condition (present from birth), it can not be inherited from the parents. Literature shows that the macrodactyly of fingers might occur due to increased growth rates of all the structural elements of the affected finger, such as the soft tissues, bones, or nerve involvement. They are often found to be associated with other conditions or syndromes that are congenital or acquired after birth.

1. Congenital Anomalies:

• Klippel Trenaunay syndrome (A rare congenital syndrome that causes developmental malformations of blood vessels, skin, muscles, and other body systems).

• Neurofibromatosis (a genetic condition that causes nerve tumors and abnormal growth in other parts of the body).

• Lipoatrophic Diabetes (A rare condition that causes diffuse loss of subcutaneous fat tissue and diabetes).

• Proteus syndrome (A rare genetic condition that results in tissue overgrowth of skin, bones, and parts of the body).

2. Acquired Anomalies: Parts of the body tend to overgrow due to these conditions.

• Resulting from inflammation due to infection or trauma.

• Due to tumors like Lipofibromatous hamartoma, osteoid osteoma (benign bone-forming tumor), and Melorrheostsosis (a rare bone disease).

• In patients with arteriovenous malformations (a tangle or abnormal connections of arteries and veins) of the limb before the development of epiphysis in long bones.

• In patients with amyloidosis (a rare genetic disorder that develops due to the deposition of abnormal proteins in the heart, liver, and other tissues).

• Elephantiasis (a disease that affects the lymph nodes and the lymphatic system).

• In patients with acromegaly - a rare condition with excessive hormone production resulting in enlargement of the body's tissues and bones.

What Is the Classification of Macrodadactyly?

The macrodactyly of fingers is classified based on the growth patterns of the finger into two types.

• The first type of macrodactyly is referred to as static since the enlargement of the fingers is present at the time of birth. The growth patterns of the affected and unaffected digits are the same.

• The second type of macrodactyly is the progressive one Since the affected fingers grow faster than the unaffected fingers. In this type, the enormous growth can cause functional deformities affecting the quality of life.

How Is Macrodactyly of Fingers Diagnosed?

Macrodactyly of fingers is usually diagnosed at birth except in the cases of a progressive type which is usually detected later in childhood. The doctor will perform various radiographic investigations to assess the internal structures and to diagnose the condition. The radiographic studies include X-ray or MRI (magnetic resonance imaging). Radiographic examinations may also be used in the pre-operative planning for the patient.

What Are the Treatment Options for the Macrodactyly of Fingers?

The primary goal of the treatment plan is to achieve the functional abilities of the affected patients and the best appearance of the hands. The treatment plan for this condition depends on the severity of the growth in these patients.

• In mild cases with unnoticeable growth of fingers, the patients are generally not advised of any treatment and are kept under observation.

• In moderate to severe cases with functional impairments and cosmetic concerns are advised for surgical interventions.

The operative management of macrodactyly is complicated and requires multiple procedures with long-term treatment planning. The surgical interventions may require a combination of the below-mentioned procedures.

• Soft Tissue debulking (surgical removal of soft tissues): This procedure aims to reduce the width of the enlarged finger. This may be performed in numerous stages three months apart. This procedure involves surgical removal of the thickened skin layers to reduce the enlargement. It is the only method that can remove osteophytes (bony overgrowth) and decrease the finger's circumferential size while maintaining the finger joints' stability. The lost tissues are replaced by healthy skin grafts that are obtained from other parts of the body. Soft tissue debulking is either performed in milder cases or combined with other severe procedures. They are often combined with shortening procedures and re-shaping of the fingertip. This procedure may result in delayed healing and scar formation post-surgically.

• Epiphysiodesis (growth plate fusion): A minimally invasive surgical procedure performed on the bone's growth plates to reduce their growth rate or to stop the growth.

• Closed Wedging Osteotomy: Surgical angulation correction procedure usually performed with Kirschner or interosseous wires.

• Ostectomy: It is a surgical procedure that involves the excision or removal of bone or a part of it.

• Amputation: In severe cases of progressive macrodactyly, surgical removal of the complete unfunctional fingers is performed.

Conclusion:

Macrodactyly of fingers is an extremely rare condition causing abnormal growth of one or more fingers. The exact cause of the condition still needs to be understood entirely. They are often found in association with other limb disorders and other syndromes. Management of this condition can be challenging. Patients with mild growth and no functional impairments are kept under observation and recommended treatment only when necessary. Treatment for severe cases requires multiple complicated procedures. There is delayed healing and scar formation post-surgically in most patients.