Fibular hemimelia

Fibular hemimelia
File:Amphibian hemimelia.jpg Hemimelia in an amphibian affecting both calf and foot on one side
Classification and external resources
Specialty
ICD-10	Q73.8
DiseasesDB	33931
Patient UK	Fibular hemimelia
MeSH	D004480

Fibular hemimelia or longitudinal fibular deficiency is "the congenital absence of the fibula and it is the most common congenital absence of long bone of the extremities." It is the shortening of the fibula at birth, or the complete lack thereof. In humans, the disorder can be noted by ultrasound in utero to prepare for amputation after birth or complex bone lengthening surgery. The amputation usually takes place at six months with removal of portions of the legs to prepare them for prosthetic use. The other treatments which include repeated corrective osteotomies and leg-lengthening surgery are costly and associated with residual deformity.

Characteristics

File:Illu lower extremity.jpg

Bones of human lower extremity

Characteristics are:

• A fibrous band instead of the fibula
• Short deformed leg
• Absence of the lateral part of the ankle joint (due to absence of the distal end of the fibula), and what is left is unstable; the foot has an equinovalgus deformity
• Possible absence of part of the foot requiring surgical intervention to bring the foot into normal function, or amputation.
• Possible absence of one or two toes on the foot

Partial or total absence of fibula is among the most frequent limb anomalies. It is the most common long bone deficiency and is the most common skeletal deformity in the leg. It most often is unilateral (present only on one side). Paraxial fibular hemimelia is the most common manifestation in which only the postaxial portion of the limb is affected. It is commonly seen as complete terminal deficiency, where the lateral rays of the foot are also affected. Hemimelia can also be intercalary in which case the foot remains unaffected. Although the missing bone is easily identified, this condition is not simply a missing bone. Males are affected twice as often as females in most series.

Causes

The cause of fibular hemimelia is unclear. Purportedly, there have been some incidents of genetic distribution in a family; however, this does not account for all cases. Maternal viral infections, embryonic trauma, teratogenic environmental exposures or vascular dysgenesis (failure of the embryo to form a satisfactory blood supply) between four and seven weeks gestation are considered possible causes.

Notable people

• Jessica Long - American Paralympic swimmer
• Aimee Mullins - American Paralympic athlete, actress, and fashion model
• Oscar Pistorius - Retired South African Paralympic and Olympic athlete

See also

• Congenital abnormality
• List of congenital disorders
• ICD-10 Chapter Q: Congenital malformations, deformations and chromosomal abnormalities
• List of ICD-9 codes 740-759: Congenital anomalies
• Mitochondrial disease

External links

• Journal of Joint Bone Surgery 1997 Jan;79(1):58-65.
• North American Reporting Center for Amphibian Malformations (NARCAM) Jul. 2011
• Minnesota's Malformed Frogs Jul. 2011
• Studies offer new insights into causes of deformed frogs Jul. 2011
• Deformed Frogs Raise Concerns Jul. 2011
• Deformed Frog Pictures Jul. 2011
• http://www.wheelessonline.com/ortho/fibular_hemimelia_longitudinal_fibular_deficiency
• http://www.sonoworld.com/TheFetus/page.aspx?id=342
• http://www.jbjs.org.uk/cgi/content/abstract/49-B/1/59
• Severe tibial growth retardation in total fibular hemimelia after limb lengthening. Journal of Pediatric Orthopaedics, 2003 http://www.jbjs.org.uk/cgi/reprint/79-B/1/58