1) Macrodactyly is an overgrowth of one or more fingers, most often the index finger. It can involve enlargement of skin, bone, nerves, and other tissues. 2) The cause is unknown but may involve abnormal nerve or blood supply. Recent evidence suggests a genetic mutation can cause abnormal growth regulation. 3) Treatment involves surgical procedures like debulking excess tissue or shortening the enlarged bones to improve appearance and function.

1. MODERATOR – PROF DR ADIL H WANI
DR G AVINASH RAO
FELLOW HAND AND
MICROSURGERY
SKIMS
MACRODACTYLY

3. OVERGROWTH (MACRODACTYLY)
 Macrodactyly is a rare congenital anomaly (0.9%) in which there is enlargement
of the finger.
 The index finger is involved most frequently.
 Macrodactyly does not seem to be an inherited condition. Although its cause is
uncertain, three possible factors are strongly suspected:
1. Abnormal Nerve Supply,
2. Abnormal Blood Supply, And
3. Abnormal Humoral Mechanism.
 Some authors have postulated that macrodactyly is an aborted type of
neurofibromatosis; But, other manifestations of this disease usually are not seen
in these patients. Recent studies have implicated a proto-oncogene
(somatic mutation of PIK3CA) mutation resulting in abnormal regulation of growth.

5. Cui, H., Han, G., Sun, B. et al. Activating PIK3CA mutation promotes
osteogenesis of bone marrow mesenchymal stem cells in macrodactyly. Cell
Death Dis 11, 505 (2020). https://doi.org/10.1038/s41419-020-2723-6
 There is nerve involvement in the affected digits, among which median nerve
is the most frequently involved.
 Aberrant distribution of neurofilament has been reported in the affected
nerve tissues.
 Osseous enlargement, osteochondromatous proliferations, hypertrophic
changes, and ankylosis of innervated joints can be observed in some areas
of innervated bone tissue.
 Mutation of PIK3CA can also be detected in the diseased nerve tissue.
 It encodes the catalytic α-subunit of PI3K (p110α). PI3K catalyzes the
conversion of phosphatidylinositol-4,5-bisphosphate (PIP2) to
phosphatidylinositol (3,4,5)-triphosphate (PIP3)

6.  True macrodactyly - involves hypertrophy of all the structures of
the digit: the skin, toenail, subcutaneous fat, bones, nerves, and
blood vessels.
Associated with - Proteus syndrome etc
 False macrodactyly - presents as hypertrophy of primarily one
tissue type.
Associated with - Ollier’s disease, Maffucci’s syndrome,
vascular malformation, neuro-fibromatosis, and Milroy’s disease

8.  Barsky described two types of true macrodactyly:
1. Static enlargement of the digit without progression as the child grows.
2. Progressive enlargement out of proportion to normal growth.
 The Progressive form may not enlarge during infancy but begins to enlarge
rapidly during early childhood; this form frequently is associated with angular
deformity.
 Macrodactyly most commonly exists without other conditions, but syndactyly
is associated with macrodactyly in about 10% of patients.
 Macrodactyly involving both the hands and the feet has been reported by
Keret, Ger, and Marks.

9.  In static macrodactyly, the deformity is present in infancy.
 There usually is diffuse enlargement of the digit; however, the distal and palmar
tissues usually appear more enlarged than the dorsal and proximal tissues.
 The finger grows, but in proportion to normal digital growth.
 Progressive macrodactyly occurs in early childhood as a rapidly enlarging
digit, frequently with an angular deformity that makes the finger banana shaped .
 The skin may be thickened, and the nails may be hypertrophied.
 The phalanges always are involved, and the metacarpals may be enlarged.
 With maturity, the enlarged digit begins to loose motion

10.  Macrodactyly affects the fingers more frequently than the toes with
concurrent upper and lower extremity involvement being extremely rare.
 In the foot, macrodactyly usually presents in the first, second or third digit;
the second digit is most frequently involved.
 When overgrowth of an adjacent digit is also present, syndactyly is not
unusual.
 Macrodactyly may be suspected to be the result of Proteus syndrome, which
is a rare disorder of skeletal, hamatomatous, and mesodermal
malformations.

11. Proteus Syndrome
 In addition to unilateral disproportionate overgrowth, other characteristic
features include connective tissue nevi, dysregulated adipose tissue, and
vascular malformation.
 Macrodactyly associated with Proteus syndrome should be differentiated
from isolated macrodactyly because it has progressive nature, poor
prognosis and high associated rates of recurrence

12.  Later in life, symptoms of carpal tunnel syndrome may develop, with complaints of
paresthesias and hypesthesias.
 Trophic ulcers also may develop over the involved digit.
 Involvement usually is unilateral, and multiple digits are affected two to three times as
often as single digits.
 If the thumb is involved, a characteristic abduction and hyperextension deformity results.
 It generally is believed that all the tissues of the involved finger are enlarged; however,
some authors have noted sparing of the tendons and vessels.
 The nerves that innervate the involved territory are characteristically enlarged.
 In a rare type of macrodactyly (hyperostotic), there may be osteocartilaginous deposits
around the joints;
 a traumatic cause for this condition has been reported.

13. Macrodactyly of index finger and
thumb

14. Treatment
 There are no satisfactory nonsurgical methods of controlling macrodactyly.
 Attempts to compress the digit with elastic wrapping have been
unsuccessful.
 Indications for surgery include enlargement, angulation, carpal tunnel
syndrome, and causalgia.
 For a progressively enlarging digit, a debulking procedure usually is needed.
With this procedure, as much excess tissue as possible is excised from one
half of the digit; 3 months later, the other half is debulked. This procedure
may be required several times during the growth period.
 Tsuge proposed that the disproportionate growth is a result of excessive
neural input and recommended that the digital nerves be stripped of one half

15.  He also recommended complete excision of the enlarged digital nerves during
debulking as the most effective way to control progressive macrodactyly,
believing that this causes only minimal neural impairment in children.
 Kelikian recommended segmental resection of the tortuous digital nerves with
end-to-end repair.
 Physeal arrest by drilling holes through the physes, resection of the physes, or
epiphysiodesis of all phalanges frequently is recommended after the digit has
reached estimated adult length.
 Various methods of digital shortening also have been described, including
simple amputation of the distal phalanx and filleting of the distal phalanx, with
transfer of the nail and matrix onto the end of the middle phalanx, with or without
some of the underlying distal phalanx

16.  In the angulated finger, closing wedge osteotomies through then proximal or
middle phalanx are necessary for correction.
 Tan et al. performed middle phalangectomy in one patient with macrodactyly
as their preferred surgical option.
 Millesi described a complicated technique for shortening the enlarged thumb,
in which parts of the distal and middle phalanges are removed and the distal
interphalangeal joint is preserved.
 Shortening procedures, however, are prone to stiffness and development of
contractures.
 Amputation is used to provide relief only as a last resort in an adult with a
severe and bothersome deformity.

17.  Although not routinely performed, long finger pollicization has been reported
for severe nonreconstructable macrodactyly of the index finger and thumb.
 The most common complication is recurrence, which is expected after
debulking. Flap necrosis is a major surgical complication, and some authors
have recommended excision of the overlying skin and replacement with a
full-thickness skin graft to avoid this problem.
 Careful attention to flap design may help prevent skin necrosis. Operating on
only one side of the finger at a time minimizes the risk of circulatory
disturbance.

19. DEBULKING (TSUGE)
 Under tourniquet control, make a midlateral incision the length of the involved
digit.
 Identify and dissect out the digital nerve.
 Excise all excessive adipose tissue.
 If the digital nerve is grossly enlarged, half the fascicles may be stripped and
excised as recommended by Tsuge. If the digital nerve is excessively tortuous, a
section can be resected and an end-to-end repair performed as described by
Kelikian.
 Resect matching sections of the volar half of the distal phalanx and the dorsal
half of the middle phalanx and reduce the fragments. Remove excessive skin,
close the incision and apply a bulky hand dressing.
 No particular postoperative protection is required.

20. A, Recurrent macrodactyly in 6-year-old child 2
years after debulking procedure of ring finger
and amputation of long finger.
B, Intraoperative photograph shows
enlargement of digital nerve.
C, Wound closure after debulking.

21. A, Matching sections (shaded areas) of volar half of distal phalanx and dorsal
half of middle phalanx are removed.
B, Distal phalanx is reduced on middle phalanx, with preservation of dorsal skin
bridge, but removal of excess soft tissue.
C, Soft-tissue closure is completed, accepting some excess dorsal soft tissue.

22. EPIPHYSIODESIS
 Under tourniquet control, make a midlateral incision the length of the entire
finger.
 Identify the physes of the proximal, middle, and distal phalanges, and
perform epiphysiodesis of these with a high-speed burr or curet and cautery.
 Close the incision and apply a finger splint, which is worn for 3 weeks.

23. DIGITAL SHORTENING (BARSKY)
 Under tourniquet control, make an L-shaped incision beginning at the midlateral
aspect of the proximal interphalangeal joint and extending distally to a level just
proximal to the germinal matrix Carry the incision transversely across the
dorsum of the finger.
 Remove the distal half of the middle phalanx and the proximal part of the distal
phalanx.
 Using a rongeur, sharpen the distal end of the remaining middle phalanx to a
point to fit into the medullary canal of the distal phalanx (Fig. 79-58B).
 Place the distal phalanx onto the middle phalanx and fix it with a Kirschner wire
to recess the finger.
 Excess volar soft tissue can be removed at a later stage.

24. A, L-shaped midlateral and dorsal incisions allow removal of excess dorsal
tissue, distal half of middle phalanx, and proximal portion of distal phalanx
(shaded area).
B, Bone ends are preparedfor pencil-cone reduction.
C, Distal phalanx is reduced on middle phalanx and secured with Kirschner
wire.

25. THUMB SHORTENING (MILLESI)
 Under tourniquet control, excise the distal half of the nail and nail matrix and the
underlying distal phalangeal tuft.
 Through a dorsal longitudinal incision overlying the proximal and distal phalanx,
remove the middle third of the distal phalanx and the middle third of the
overlying nail and matrix.
 Remove the middle third of the proximal phalanx by making parallel oblique
osteotomies.
 Reduce the two remaining longitudinal components of the distal phalanx and pin
them with a transverse Kirschner wire.
 Reduce the distal and proximal fragments of the proximal phalanx in a shortened

26.  Close the wound by carefully approximating the skin edges and the nail
matrix, leaving the Kirschner wires protruding through the skin.
 Apply a thumb splint.
 POSTOPERATIVE CARE. The splint is worn for 3 weeks.
 The Kirschner wires are removed when the osteotomy incisions are healed,
usually by 4 to 6 weeks.

27. A, Removal of distal half of nail and distal phalanx, preserving eponychial tissue.
B, Reduction osteotomies performed through dorsal incision.
C, Remaining bone reduced and pinned.

28. Thank you