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Depending on the severity of the deformities, the treatment may include the amputation of the foot or part of the leg, lengthening of the femur, extension prosthesis, or custom shoe lifts. Amputation usually requires the use of prosthesis. Another alternative is a rotationplasty procedure, also known as Van Ness surgery. In this situation the foot and ankle are surgically removed, then attached to the femur. This creates a functional "knee joint". This allows the patient to be fit with a below knee prosthesis vs a traditional above knee prosthesis.
In less severe cases, the use of an Ilizarov apparatus can be successful in conjunction with hip and knee surgeries (depending on the status of the femoral head/kneecap) to extend the femur length to normal ranges. This method of treatment can be problematic in that the Ilizarov might need to be applied both during early childhood (to keep the femur from being extremely short at the onset of growth) and after puberty (to match leg lengths after growth has ended). The clear benefit of this approach, however, is that no prosthetics are needed and at the conclusion of surgical procedures the patient will not be biologically or anatomically different from a person born without PFFD.
Dysmelia (from Gr. δυσ- "dys", "bad" + μέλ|ος "mél|os", "limb" + Eng. suff. -ia) is a congenital disorder of a limb resulting from a disturbance in embryonic development.
Dysmelia can be caused by
- inheritance of abnormal genes, e.g. polydactyly, ectrodactyly or brachydactyly, symptoms of deformed limbs then often occur in combination with other symptoms (syndromes)
- external causes during pregnancy (thus not inherited), e.g. via amniotic band syndrome
- teratogenic drugs (e.g. thalidomide, which causes phocomelia) or environmental chemicals
- ionizing radiation (nuclear weapons, radioiodine, radiation therapy)
- infections
- metabolic imbalance
Ectromelia is a congenital condition where long bones are missing or underdeveloped.
Examples include:
- Amelia
- Hemimelia
- Phocomelia
- Sirenomelia
Hemimelia comprises
- Fibular hemimelia, Congenital longitudinal deficiency of the fibula or Fibular longitudinal meromelia
- Tibial hemimelia, Congenital longitudenal deficiency of the tibia, Congenital aplasia and dysplasia of the tibia with intact fibula, Congenital longitudinal deficiency of the tibia or Tibial longitudinal meromelia
- Radial Hemimelia, Congenital longitudinal deficiency of the radius, Radial clubhand, Radial longitudinal meromelia or Radial ray agenesis
- Ulnar hemimelia, Congenital longitudinal deficiency of the ulna, Ulnar clubhand or Ulnar longitudinal meromelia
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.
In an experimental mouse model, change in the expression of a homeobox gene led to similar, but bilateral, fibular defects.
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 (Ilizarov apparatus) are costly and associated with residual deformity.
Acheiropodia (ACHP), also known as Horn-Kolb Syndrome, Acheiropody and Aleijadinhos (Brazilian type), is an autosomal recessive disorder that results in hemimelia, a lack of formation of the distal extremities.
This is a congenital defect which consists of bilateral amputations of the distal upper and lower extremities, as well as aplasia of the hands and feet. It was first discovered and is prevalent almost exclusively in Brazil.
Presence at birth is extremely rare and associated with other congenital anomalies such as proximal femoral focal deficiency, fibular hemimelia or anomalies in other part of the body such as cleidocranial dyastosis. The femoral deformity is present in the subtrochantric area where the bone is bent. The cortices are thickened and may be associated with overlying skin dimples. External rotation of the femur with valgus deformity of knee may be noted. This condition does not resolve and requires surgical management. Surgical management includes valgus osteotomy to improve hip biomechanics and length and rotational osteotomy to correct retroversion and lengthening.
The cause of PFFD is uncertain. Two hypotheses have been advanced. The theory of sclerotome subtraction posits injury to neural crest cells that are the precursors to sensory nerves at the level of L4 and L5. Histologic studies of a fetus with unilateral PFFD have prompted an alternative hypothesis that PFFD is caused by a defect in maturation of chondrocytes (cartilage cells) at the growth plate. In either hypothesis, the agent causing the injury is usually not known. Thalidomide is known to cause PFFD when the mother is exposed to it in the fifth or sixth week of pregnancy, and it is speculated that exposure to other toxins during pregnancy may also be a cause. Other etiologies that have been suggested, but not proven, include anoxia, ischemia, radiation, infection, hormones, and mechanical force. PFFD occurs sporadically, and does not appear to be hereditary.
ACHP has been associated with a mutation in the "LMBR1" gene. The disorder is inherited in an autosomal recessive manner. This means the defective gene responsible for the disorder is located on an autosome, and two copies of the defective gene (one inherited from each parent) are required in order to be born with the disorder. The parents of an individual with an autosomal recessive disorder both carry one copy of the defective gene, but usually do not experience any signs or symptoms of the disorder.
More common cause: primary defect in endochondral ossification of the medial part of the femoral neck.
Excessive interuterine pressure on the developing fetal hip.
vascular insult.
Faulty maturation of the cartilage and metaphyseal bone of the femoral neck.
Clinical feature: presents after the child has started walking but before six years of age. Usually associated with a painless hip due to mild abductor weakness and mild limb length discrepancy.
If there is a bilateral involvement the child might have a waddling gait or trendelenburg gait with an increased lumbar lordosis. The greater trochanter is usually prominent on palpation and is more proximal. Restricted abduction and internal rotation.
X-ray: decreased neck shaft angle, increased cervicofemoral angle, vertical physis, shortened femoral neck decrease in femoral anteversion. HE angle (hilgenriener epiphyseal angle- angle subtended between a horizontal line connecting the triradiate cartilage and the epiphysisn normal angle is <30 degrees.
Treatment:
HE angle of 45–60 degrees observation and periodic follow up.
Indication for surgery :HE angle more than 60 degrees, progressive deformity, neckshaft angle <90 degrees, development of trendelenburg gait
Surgery: subtrochantric valgus osteotomy with adequate internal rotation of distal fragment to correct anteversion
common complication is recurrence. If HE angle is reduced to 38 degrees less evidence of recurrence
post operative spica cast is used for a period of 6–8 weeks.
Coxa vara is also seen in Niemann–Pick disease.