(From Pediatric Directions, Issue 39)
The Hand, Microsurgery and Brachial Plexus Program offers psychosocial, therapeutic and surgical care to patients with congenital hand differences and upper extremity differences. Polydactyly, syndactyly, thumb hypoplasia, radial deficiency, ulnar deficiency and overgrowth are examples of some of the diagnoses treated by this multidisciplinary team.
Congenital upper extremity difference are classified into the following categories: failure of formation, failure of formation, failure of differentiation, duplication, overgrowth, undergrowth, constriction band sequence and generalized skeletal abnormalities. The most common diagnoses referred to the Hand, Microsurgery and Brachial Plexus Program are polydactyly and syndactyly. These are examples of duplication and failure of differentiation, respectively, and most often require outpatient surgery. Complicated syndacty, such as Apert’s syndrome or Constriction Band syndrome, complex polydacty, thumb hypoplasia, radial deficiency, ulnar deficiency and overgrowth are examples of some of the more complex diagnoses treated by our multidisciplinary team. These diagnoses can involve multiple surgeries, therapy and the need for psychological support.
Congenital hand differences are not uncommon. There are between 1/500 and 1/1000 children born with congenital differences of the upper extremity 1 2, making upper extremity differences second only to congenital heart disease in the incidence of birth malformations 1. The cause of congenital differences is unknown in 60 percent of cases and a smaller amount may have genetic or environmental factors 3.
For those children that do require surgery, we strive to improve the function and aesthetic appearance of the affected extremity to improve their quality of life. The timing of surgical interventions depends on a multitude of factors: anesthetic safety, hand function and development, growth causing ongoing deformity, psychosocial concerns, technical difficulty of the procedure, and whether patient participation is necessary for post-operative recovery.
Macrodactyly is the disproportionate enlargement of a digit at birth or shortly thereafter. The most common type of macrodactyly is congenital, unilateral, non-hereditary and involves enlargement of fatty and skeletal structures. This form is most commonly referred to as macrodystrophia lipomatosa (ML) or type I macrodactyly. Many hypotheses have been proposed regarding the pathogenesis. These include lipomatous degeneration, fetal circulation abnormality along with damage of the extremity bud, errors in the segmentation in intrauterine life, and hypertrophy of the involved nerve 7.
Type I Macrodactyly or ML is also referred to as congenital localized gigantism, gigantism with lipofibromatosis, and megalodactyly. Regardless of the terminology, ML is a rare condition that causes overgrowth of an extremity through general mesenchymal proliferation with a disproportionate overgrowth of fibro-adipose tissue with bony overgrowth. In the upper extremity, the overgrowth is often in the distribution of the median nerve. In the lower extremity the distribution is that of the medial plantar nerve 6. This condition can be categorized as a static form, in which the overgrowth is present as an infant or toddler and grows in conjunction with the child, or as a progressive form, in which the mass grows disproportionately faster than the rest of the child. It is sometimes difficult to differentiate the static from progressive forms. There are case reports in the literature that were thought to be static and later underwent a more progressive course.
Radiographic findings include bony and soft tissue overgrowth with elongated, broad and splayed phalanges. Early signs of osteoarthritis are often present 4. On MRI, there is an excess of fibro-fatty tissue, which has the same characteristics as fat on T1 and T2 weighted images (i.e., high signal) but also has low signal stranding on T1 weighted images. The fat may infiltrate into surrounding muscle. Bone cortical thickening, secondary degenerative changes, and fibrous thickening of the nerve may also be observed.
As seen in the medical illustrations, Figures 1-6, histologically, the lesion appears as fibro-fatty overgrowth with no enlarged blood or lymphatic vessels. It is the same appearance as fibrolipomatous hamartoma of the nerve with the additional history of overgrowth. The periosteum and bone show an increase in a fine mesh of fibrous tissue 4. Phalanges are enlarged due both to endosteal and periosteal deposition of bone 4.
The diagnosis can be confirmed with appropriate clinical history, radiographic findings, histologic confirmation and the absence of cutaneous stigmata that would suggest alternate diagnoses, such as neurofibromatosis, Klippel-Trenaunay, lymphangiomatosis, hemangiomatosis, fibrolipomatosis hamartoma (without bony overgrowth), Mafucci syndrome, Ollier disease and proteus syndrome.
This condition often requires multiple operations for aesthetic and functional reasons. These include degenerative joint changes, neurovascular compression, gait abnormalities (with lower extremity lesions) and psychosocial issues due to limb discrepancy. The patient, family and clinical team must work together to establish realistic goals, maximize outcomes and minimize complications.
Case Study: Hannah’s Story
Hannah is a 14-year-old, right-handed dominant girl who was originally seen by Dr. James Popp when she was 12 years old. She had an overgrowth of her left chest wall, upper arm, forearm, hand and middle finger since birth. The enlarging middle finger was becoming stiffer and she was having difficulty fitting into clothing due to the size discrepancy between her arms. She was functioning well despite being self-conscious about her larger left arm and middle finger. She and her parents had been seen at several other hospitals, and she had a previous excisional biopsy of an infiltrating lipoma on the left side of her neck. The areas on her left upper extremity had progressively enlarged as she grew but did not have a history of any period of rapid growth. From her previous studies and the pathology of the lesion removed, an overgrowth syndrome was suspected. However, Hannah and her parents were discouraged at the treatment options they had been offered to date.
Hannah’s MRI was repeated and the results indicated a fatty overgrowth with no significant vascular component and overgrowth of the bones in her left upper extremity central ray. The lesion was not amenable to treatment by our interventional radiologists. Surgical debulking was planned in two stages to obtain more tissue for a definitive diagnosis before the second surgery. Since the family is not from Columbus, her postoperative hand therapy was coordinated with a therapist closer to her home.
Her first surgery included debulking the fatty overgrowth on the dorsum of her hand and around her middle finger. Additionally, the destruction of the growth plates in her middle finger was achieved to prevent further longitudinal growth. Finally, her last joint (the distal interphalangeal), which was already stiff, was fused.
During recovery, and while Hannah was continuing therapy to prevent hand stiffness, the pathology of the lesion was determined to be fibrolipomatous hamartoma of nerves. This pathology, combined with 1) her plain X-ray findings of early arthritis in her central ray joints, and 2) the fatty infiltration with bony overgrowth seen on her MRI with the absence of any skin manifestations, provided a diagnosis consistent with Type 1 macrodactyly, likely a slowly progressive form.
A second surgery was performed to debulk her upper arm tissue and excise some of the fibrofatty tissue from her lateral chest wall and scapula area. To minimize scarring, the fibrofatty tissue on her arm was removed with liposuction.
Hannah has fully recovered from her surgeries and is now enjoying summer with more confidence to wear short sleeves. However, her left arm will always be larger, and the possibility of additional surgeries exists to alleviate pain or stiffness in her finger, or re-growth of the fatty deposits. Overall, Hannah has had a good recovery and a successful outcome. She is able to enter her teenage years with more self-assurance.
Although macrodactyly is not as common as some other congenital hand differences, it demonstrates the breadth and depth of the abilities of the Hand, Microsurgery and Brachial Plexus Program team. This multidisciplinary team of clinicians and other allied health specialties work together to meet the needs of every patient’s diagnosis. No matter how common or rare the upper extremity or congenital hand differences are, the goal for the team is to help those children function independently and participate in activities that they love.
View an interview with Drs. Spaeth and Popp regarding treatment for Hannah’s congenital hand differences.
Maya C. Spaeth, MD, CFP, is co-director of the Hand, Microsurgery and Brachial Plexus Program at Nationwide Children’s with Dr. James Popp. She is also a member of the Section of Plastic Surgery at Nationwide Children’s Hospital and a clinical assistant professor of plastic surgery at Ohio State University College of Medicine. Dr. Spaeth has been published in leading professional publications and is actively involved in research on congenital hand, brachial plexus, hemangioma and vascular malformations, and resident education.
She came to Nationwide Children’s from Loma Linda University, where she served as Assistant Professor of Plastic Surgery and was actively involved in resident education. Dr. Spaeth received her Bachelor of Science from the University of British Columbia and attended Medical School at the University of Calgary. She completed residency training in Family Medicine at Dalhousie and a second residency in plastic surgery at The Ohio State University Wexner Medical Center. She finished a Hand and Microsurgery fellowship at Baylor College of Medicine and recently completed two observerships in Toronto and Boston for Brachial Plexus and Facial Reanimation. She is board certified by the American Board of Plastic Surgery in both Plastic and Reconstructive Surgery and Hand Surgery.
Amor, C J, Spaeth M, Chafey D, Gogola, G. Use of the Pediatric Data Outcomes Collection Instrument to Evaluate Functional Outcomes in Arthrogryposis. J Pediatr Orthop 2011 Apr-May;31(3):293-6
Workman M, Spaeth M. Lymphovenous Malformation involving the Brachial plexus. Poster presentation at The International Society for the Study of Vascular Anomalies (ISSVA), Malmo Sweden June 2012
James E. Popp, MD, is co-director of the Hand, Microsurgery and Brachial Plexus Program at Nationwide Children’s Hospital with Dr. Maya Spaeth. He is also a faculty member of the Department of Orthopedics at Nationwide Children’s and a clinical assistant professor at the Ohio State University College of Medicine. Dr. Popp specializes in surgery of the hand and upper extremity in adult and pediatric patients. He has been published in various medical journals, and he is actively involved in research and resident education. He attended medical school at Case Western Reserve University School of Medicine and completed his residency at The Ohio State University. Dr. Popp then completed a Hand and Upper Extremity Surgery Fellowship at the distinguished Indiana Hand Center, Indianapolis, Indiana. He is a member of the American Board of Orthopaedic Surgeons, American Society for Surgery of the Hand, Mid-American Orthopaedic Association, American Academy of Orthopaedic Surgeons, American Medical Association and the Ohio State Medical Association.
Bono KT, Popp JE, Intraosseous median nerve entrapment following pediatric posterior elbow dislocation. Orthopedics. 2012 Apr;35(4):e592-4
Samora JB, Howard, Durbin D., Popp, JE, Endobutton fixation of distal biceps tendon injuries: Outcomes in a private practice setting. Current Orthopaedic Practice. Vol. 23, Number 1. 2012
Horn, P, Popp, JE, Case in Point: Snake Bite: A Small Puncture Can Create a Large Problem. Consul for Pediatricians 5(5): 297-302, May 2007.
James J. O’Shea, OT, CHT, is a hand therapist working with children who have congenital, orthopedic, neurological, or developmental injuries or diagnoses. The goal of hand therapy is to help return patients to using their upper extremities for functional activities and daily living activities. O’Shea holds a BS and MS in Occupational Therapy from Quinnipiac University, Hamden, Connecticut. His areas of specialty are Hand Therapy and Lymphedema Therapy. He is a member of the American Society of Hand Therapists and American Occupational Therapy Association.