Index
Also called digital gigantism, it is an extremely rare, non-hereditary, congenital deformity.
Macrodactyly is characterized by hyperplasia of one or more digits.
In real cases, all the physical structures of the affected digit are enlarged. The etiology of macrodactyly is not completely clear; it may be related to a neurogenic disorder or due to an overgrowth of tumors of a single tissue type in the affected digit.
People with moderate to severe macrodactyly may experience pain and a reduced range of motion (ROM), which often affects hand function.
Although ongoing observation may be appropriate for mild cases with few functional limitations, surgery, including soft tissue reduction, epiphysiodesis, osteotomy, ostectomy, and amputation, is often necessary for more severe cases.
Causes
A root cause for macrodactyly has not yet been found.
It definitely does not occur due to something done by the mother during the pregnancy. Macrodactyly is not an inherited disorder.
Macrodactyly appears to occur in conjunction with some other congenital conditions including neurofibromatosis , vascular abnormalities, tuberous sclerosis, or other conditions.
Pathophysiology
Proposed mechanisms include:
- Association with a neurogenic disorder, constituting a component of neurofibromatosis.
- Alteration of the growth limiting factor during development, resulting in a local increase in size.
- Tumor overgrowth of a single tissue element in the digit, as in hemangioma, lymphangioma, or enchondroma.
- Lipomatous degeneration and alteration of fetal circulation and local growth promotion / inhibition factors.
Classification systems to describe macrodactyly
True macrodactyly and pseudomacrodactyly
Pseudomacrodactilia
Hamartomatous enlargement of all mesenchymal elements of the fingers (phalanges, tendons, nerves, blood vessels, subcutaneous fat, nails, skin coverings), but the adjacent metacarpals are usually not affected.
True macrodactyly has been classified as static or progressive:
- Static : present at birth, and marked overgrowth increases proportionally throughout development.
- Progressive : Not as noticeable at birth, but marked overgrowth increases disproportionately faster than the rest of the limb throughout development.
Another classification system proposes four types of macrodactyly:
- Type I: Comorbid lipofibromatosis of a nerve, and a static or progressive subtype.
- Type II: associated with neurofibromatosis.
- Type III: associated with hyperostosis.
- Tipo IV: asociado and hemihipertrofrof.
Related anatomy
Macrodactyly encompasses a variety of clinical phenotypes, and the rate, location, and degree of overgrowth are very different between patients.
One or more digits may be involved, and the affected digits are always adjacent.
The index finger is the most affected, followed by the long finger, the thumb, the ring finger and the little finger.
Incidence and related conditions
Macrodactyly of the hands accounts for approximately 0.9% of all congenital anomalies of the upper extremities; It is less common on the feet.
Macrodactyly is slightly more common in men than women.
Macrodactyly is associated with other syndromes, such as:
- Proteus.
- Carpal tunnel.
- Bannayan.
- Riley.
- Ruvalcaba.
- Maffucci.
- Klippel.
- Trenaunay.
- Weber.
Macrodactyly is associated with other dactylias, such as:
- Sindactyly.
- Polydactyly.
- La clinodactilia.
- Congenital macrodactyly simplex or macromelia.
- Hemihipertrophy.
- Neurofibromatosis or lipofibromatous hamartoma of the median nerve.
- Milroy’s disease or Ollier’s disease.
- Adrenal carcinoma, hepatoblastoma, or Wilm’s tumor.
Differential diagnosis
- Protein syndrome.
- Arteriovenous malformation (AVM).
- Congenital lymphangioma.
- Progressive lipomatous macrodystrophy.
Exam Findings, Signs, and Positive Tests
The diagnosis of macrodactyly is based primarily on a physical examination and the patient’s history in most cases.
The physical examination should consist of palpation and inspection of the thick and fatty tissue of the involved finger, as well as the alteration of ROM and / or instability.
If macrodactyly is found during a fetal scan, a thorough evaluation of all systems is recommended, with particular attention to soft tissue and serial scans for the development of additional findings, such as hemihypertrophy or signs of hydrops fetalis.
A detailed family history and examination of family members can also help diagnose an autosomal dominant syndrome associated with macrodactyly if one is present.
The symptoms
The defining feature of macrodactyly is that one or more of children’s fingers or toes are abnormally larger than the other fingers or toes.
If a child has macrodactyly, this does not mean that the affected toe does not grow, in fact, the affected toe also grows in the same way as the other toes, although the affected fingers may grow faster than the fingers or toes. normal.
If the condition progressively worsens, the affected finger or finger will become gigantic compared to the static condition in which the affected finger or finger is approximately twice as large as the normal finger or finger.
Typical story
The typical patient is a 16-year-old left-handed child. As he matured, the boy’s parents noticed that his right index and long fingers were growing abnormally faster than the other fingers on his hand.
This enlargement process continued throughout the child’s development, and eventually the affected two digits increased in size to a point where the other fingers dwarfed.
As the fingers grew, the child experienced progressively limited ROM, reduced functionality of the affected hand, and occasional pain.
These symptoms made it difficult for him to perform many basic daily activities (such as writing, driving, opening doors), and therefore the parents decided it was time to consider surgery to treat his condition.
Positive tests, exams, or signs
Preparation options
- Radiology studies: x-rays.
- Radiology studies: angiogram.
Treatment options
Conservative
In mild cases, where the affected digit is not significantly enlarged and the patient does not experience any functional limitations or other symptoms, ongoing observation alone may be sufficient.
Operative
Surgical intervention may be necessary in severe and / or progressive cases of macrodactyly; the patient’s age, extent and type of overgrowth, the digits involved, and patient and surgeon preference must all be carefully considered when determining the optimal treatment approach.
It is crucial to distinguish whether the patient has macrodactyly of the static or progressive type as soon as possible.
Although the principles of treatment are the same, patients with progressive macrodactyly can expect to undergo earlier surgery, have a greater number of subsequent procedures, and develop earlier interphalangeal joint osteoarthritis.
Soft tissue shortage
One of the simplest procedures for macrodactyly.
It may be recommended if the patient’s digit is circumferentially overgrown but shorter than the parent’s digit.
Soft tissue enlargement, recurrence, or progressive persistence is an indication for further volume reduction.
Epifisiodesis
Most commonly performed surgical procedure.
Normally indicated when a single digit is affected.
It can be combined with volume reduction if the digit approaches the size of the leading digit to stop further longitudinal growth.
- Ostectomy – Used to shorten the affected digits in cases of continued overgrowth.
- Closing wedge osteotomy: Usually indicated if the thumb or multiple digits are involved.
Lightning amputation
It should be reserved only for severely enlarged, unsightly and rigid digits that are not functional
It may also be indicated in cases where severe regrowth, pain, or deformity occurs after a reconstruction attempt.
Finger transfer
Microvascular transfer of the big toe may be considered in cases that indicate a thumb amputation.
- Artrodesis.
- Neurolysis
Post-surgical rehabilitation may be necessary and should include soft tissue care and early ROM exercises.
Complications
- Hypertrophic scarring.
- Chronic digital pain.
- Edema.
- Diminished sensation.
- Flexion contracture.
- Nail hook.
- Ungual deformity.
- Stiffness of the interphalangeal joints.
- Loss of range of motion.
Results
Most patients are concerned with obtaining normal appearance and function in the affected finger (s) after surgery; however, a “normal” finger cannot be achieved in most cases. Therefore, counseling patients and their parents about such expectations is important.
Expectations should focus on producing an “acceptable” finger, which is possible in the vast majority of cases if a good combination of treatment options is used, even if the condition is progressive and severe.
Studies have reported highly variable results, mainly due to the heterogeneity of macrodactyly. In general, functional results are often superior to aesthetic results.
Key educational points
A variety of terms, including: megalodactyly, lipomatous macrodystrophy, fibrolipomatosis macrodactyly, lipomatous overgrowth or hamartoma, gigantomegaly, local gigantism, and digital gigantism, have been used to describe macrodactyly, highlighting the confusion over the nomenclature of the condition.
Congenital macrodactyly is the most appropriate term.
Macrodactyly is one of the most difficult congenital anomalies of the hand to treat. With a greater understanding of the disease process, treatment is becoming more proactive and, at the same time, more complex.
Most children with macrodactyly will require more than one procedure, particularly those with the progressive type.
The limited information on the results and technical challenges of reconstruction may contribute to a recommendation for early amputation, which many patients consider an unacceptable option.
Gene-targeting therapy for macrodactyly is under development.
Macrodactyly can appear on fingers and toes.
