Genu varum (also called bow-leggedness, bandiness, bandy-leg, and tibia vara) is a
varus deformity Varus may refer to:
* Var River or Varus, a river in France
* Stura di Lanzo or Varus, a river in Italy
* Varus deformity, a medical term for the inward angulation of the distal segment of a bone or joint
** Coxa vara, affecting the hip
** Genu varu ...
marked by (outward) bowing at the
knee
In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia (tibiofemoral joint), and one between the femur and patella (patellofemoral joint). It is the largest joint in the hu ...
, which means that the lower
leg
A leg is a weight-bearing and animal locomotion, locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single ...
is angled inward (
medially) in relation to the
thigh
In human anatomy, the thigh is the area between the hip (pelvis) and the knee. Anatomically, it is part of the lower limb.
The single bone in the thigh is called the femur. This bone is very thick and strong (due to the high proportion of bone ...
's axis, giving the limb overall the appearance of an archer's
bow. Usually medial angulation of both lower limb bones (
femur
The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...
and
tibia
The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...
) is involved.
Causes
If a child is sickly, either with
rickets
Rickets is a condition that results in weak or soft bones in children, and is caused by either dietary deficiency or genetic causes. Symptoms include bowed legs, stunted growth, bone pain, large forehead, and trouble sleeping. Complications may ...
or any other ailment that prevents ossification of the bones or is improperly fed, the bowed condition may persist. Thus the chief cause of this deformity is
rickets
Rickets is a condition that results in weak or soft bones in children, and is caused by either dietary deficiency or genetic causes. Symptoms include bowed legs, stunted growth, bone pain, large forehead, and trouble sleeping. Complications may ...
. Skeletal problems,
infection
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dise ...
, and
tumor
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
s can also affect the growth of the leg, sometimes giving rise to a one-sided bow-leggedness. The remaining causes are occupational, especially among
jockey
A jockey is someone who rides horses in horse racing or steeplechase racing, primarily as a profession. The word also applies to camel riders in camel racing. The word "jockey" originated from England and was used to describe the individual ...
s, and from
physical trauma
An injury is any physiological damage to living tissue caused by immediate physical stress. An injury can occur intentionally or unintentionally and may be caused by blunt trauma, penetrating trauma, burning, toxic exposure, asphyxiation, ...
, the condition being very likely to supervene after accidents involving the
condyles
A condyle (;Entry "condyle"
in
femur
The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...
.
[
]
Childhood
Children until the age of 3 to 4 have a degree of genu varum. The child sits with the soles of the feet facing one another; the tibia
The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...
and femur
The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...
are curved outwards; and, if the limbs are extended, although the ankles are in contact, there is a distinct space between the knee-joints. During the first year of life, a gradual change takes place. The knee-joints approach one another; the femur
The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...
slopes downward and inward towards the knee joints; the tibia
The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...
become straight, and the sole of the foot
The foot ( : feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is a separate organ at the terminal part of the leg made ...
faces almost directly downwards.
While these changes are occurring, the bones, which at first consist principally of cartilage
Cartilage is a resilient and smooth type of connective tissue. In tetrapods, it covers and protects the ends of long bones at the joints as articular cartilage, and is a structural component of many body parts including the rib cage, the neck an ...
, are gradually becoming ossified
Ossification (also called osteogenesis or bone mineralization) in bone remodeling is the process of laying down new bone material by Cell (biology), cells named osteoblasts. It is synonymous with bone tissue formation. There are two processes ...
. By the time a normal child begins to walk, the lower limbs are prepared, both by their general direction and by the rigidity of the bones which form them, to support the weight of the body.
Rickets
Nutritional rickets
Rickets is a condition that results in weak or soft bones in children, and is caused by either dietary deficiency or genetic causes. Symptoms include bowed legs, stunted growth, bone pain, large forehead, and trouble sleeping. Complications may ...
is an important cause of childhood genu varum or bow legs in some parts of the world. Nutritional rickets is due to unhealthy life style habits as insufficient exposure to sun light which is the main source of vitamin D. Insufficient dietary intake of calcium is another contributing factor. Rickets may also have genetic causes, occasionally called resistant rickets. Rickets usually causes bone deformities in all four extremities. Genu varum may resolve spontaneously with modification of life style activities or after receiving medical treatment. Some deformities do not correct spontaneously and need surgical intervention especially if they are severe and causing gait difficulties. The main surgical modality used to treat genu varum arising from rickets is guided growth surgery, also known as growth modulation surgery.
Blount's disease
Blount's disease
Blount's disease (or Blount disease) is a growth disorder of the tibia (shin bone) which causes the lower leg to angle inward, resembling a bowleg. It is also known as "tibia vara".
Description and risk factors
Blount disease is a growth disorder ...
is a deformity in the legs, mostly from the knees to the ankles. The affected bone curves in or out and forms the usual "archers bow" which can also be called bow-legs. There are two types of Blount's disease. The first type is Infantile: this means that children under four are diagnosed with this disease. Blount's disease in this age is very risky because sometimes it is not detected and it passes to the second type of Blount's disease. The second type of Blount's disease is found mostly in older children and in teenagers, sometimes in one leg and sometimes in both; the patient's age determines how severe the diagnosis is.
Osteochondrodysplasia
Osteochondrodysplasia
Osteochondrodysplasia is a general term for a disorder of the development (dysplasia) of bone ("osteo") and cartilage ("chondro"). Osteochondrodysplasias are rare diseases. About 1 in 5,000 babies are born with some type of skeletal dysplasia. Non ...
are a diverse group of genetic bone diseases or genetic skeletal dysplasias that manifest in generalized bone deformities involving the extremities and the spine. Bow legs or genu varum is one of these deformities. The characteristic bone X-ray survey findings are important to confirm the diagnosis.
Diagnosis
On projectional radiography
Projectional radiography, also known as conventional radiography, is a form of radiography and medical imaging that produces two-dimensional images by x-ray radiation. The image acquisition is generally performed by radiographers, and the images ...
, the degree of varus or valgus deformity can be quantified by the ''hip-knee-ankle angle'', which is an angle between the femoral mechanical axis and the center of the ankle joint
The ankle, or the talocrural region, or the jumping bone (informal) is the area where the foot and the leg meet. The ankle includes three joints: the ankle joint proper or talocrural joint, the subtalar joint, and the inferior tibiofibular join ...
. It is normally between 1.0° and 1.5° of varus in adults. Normal ranges are different in children.
File:Hip-knee-ankle angle by age.png, ''Hip-knee-ankle angle'' by age, with 95% prediction interval
In statistical inference, specifically predictive inference, a prediction interval is an estimate of an interval in which a future observation will fall, with a certain probability, given what has already been observed. Prediction intervals are o ...
.[
]
Treatment
Generally, no treatment is required for idiopathic
An idiopathic disease is any disease with an unknown cause or mechanism of apparent wikt:spontaneous, spontaneous origin. From Ancient Greek, Greek ἴδιος ''idios'' "one's own" and πάθος ''pathos'' "suffering", ''idiopathy'' means approxi ...
presentation as it is a normal anatomical variant in young children. Treatment is indicated when it persists beyond years old. In the case of unilateral presentation or progressive worsening of the curvature, when caused by rickets
Rickets is a condition that results in weak or soft bones in children, and is caused by either dietary deficiency or genetic causes. Symptoms include bowed legs, stunted growth, bone pain, large forehead, and trouble sleeping. Complications may ...
, the most important thing is to treat the constitutional disease
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
, at the same time instructing the care-giver never to place the child on their feet. In many cases, this is quite sufficient in itself to effect a cure, but matters can be hastened somewhat by applying splints
Splints is an ailment of the horse or pony, characterized by a hard, bony swelling, usually on the inside of a front leg, lying between the splint and cannon bone or on the splint bone itself. It may be "hot," meaning that it occurred recently an ...
. When the deformity arises in older patients, either from trauma
Trauma most often refers to:
* Major trauma, in physical medicine, severe physical injury caused by an external source
* Psychological trauma, a type of damage to the psyche that occurs as a result of a severely distressing event
*Traumatic i ...
or occupation, the only permanent treatment is surgery
Surgery ''cheirourgikē'' (composed of χείρ, "hand", and ἔργον, "work"), via la, chirurgiae, meaning "hand work". is a medical specialty that uses operative manual and instrumental techniques on a person to investigate or treat a pat ...
, but orthopaedic
Orthopedic surgery or orthopedics ( alternatively spelt orthopaedics), is the branch of surgery concerned with conditions involving the musculoskeletal system. Orthopedic surgeons use both surgical and nonsurgical means to treat musculoskeletal ...
bracing can provide relief.
Rickets
Rickets
Rickets is a condition that results in weak or soft bones in children, and is caused by either dietary deficiency or genetic causes. Symptoms include bowed legs, stunted growth, bone pain, large forehead, and trouble sleeping. Complications may ...
usually causes bone deformities in all four extremities. Genu varum may resolve spontaneously with modification of lifestyle activities or after receiving medical treatment. Some deformities do not correct spontaneously and need surgical intervention especially if they are severe and causing gait difficulties. The main surgical modality used to treat genu varum arising from rickets
Rickets is a condition that results in weak or soft bones in children, and is caused by either dietary deficiency or genetic causes. Symptoms include bowed legs, stunted growth, bone pain, large forehead, and trouble sleeping. Complications may ...
is guided growth surgery, also known as growth modulation surgery.
Blount's disease
Treatment for children with Blount's disease is typically braces but surgery may also be necessary. In children guided growth surgery is used to gradually correct/straighten the bow legs. For teenagers osteotomy or bone cutting is often used to correct the bone deformity. The operation consists of removing a piece of tibia, breaking the fibula and straightening out the bone; there is also a choice of elongating the legs. If not treated early enough, the condition worsens quickly.
Osteochondrodysplasia
Guided growth surgery in children is widely used to achieve gradual correction of knee deformities arising from Osteochondrodysplasia
Osteochondrodysplasia is a general term for a disorder of the development (dysplasia) of bone ("osteo") and cartilage ("chondro"). Osteochondrodysplasias are rare diseases. About 1 in 5,000 babies are born with some type of skeletal dysplasia. Non ...
including genu varum. Yet, this treatment is associated with a high incidence of recurrence and repeated surgeries may be needed to maintain proper bone alignment.
Prognosis
In most cases persisting after childhood, there is little or no effect on the ability to walk. Due to uneven stress and wear on the knees, however, even milder manifestations can see an accelerated onset of arthritis
Arthritis is a term often used to mean any disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, swelling, and decreased range of motion of the affected joints. In som ...
.
See also
* Genu valgum Genu, a Latin word for "knee," may refer to:
* Genu of internal capsule
* Genu of the corpus callosum
* Genu recurvatum
* Genu valgum
* Genu varum
Genu varum (also called bow-leggedness, bandiness, bandy-leg, and tibia vara) is a varus deform ...
* Genu recurvatum
Genu recurvatum is a deformity in the knee joint, so that the knee bends backwards. In this deformity, excessive extension occurs in the tibiofemoral joint. Genu recurvatum is also called knee hyperextension and back knee. This deformity is mor ...
* Varus deformity Varus may refer to:
* Var River or Varus, a river in France
* Stura di Lanzo or Varus, a river in Italy
* Varus deformity, a medical term for the inward angulation of the distal segment of a bone or joint
** Coxa vara, affecting the hip
** Genu varu ...
* Rickets
Rickets is a condition that results in weak or soft bones in children, and is caused by either dietary deficiency or genetic causes. Symptoms include bowed legs, stunted growth, bone pain, large forehead, and trouble sleeping. Complications may ...
* Knee pain
Knee pain is pain in or around the knee.
The knee joint consists of an articulation between four bones: the femur, tibia, fibula and patella. There are four compartments to the knee. These are the medial and lateral tibiofemoral compartments, the ...
* Knee osteoarthritis
Osteoarthritis (OA) is a type of degenerative joint disease that results from breakdown of joint cartilage and underlying bone which affects 1 in 7 adults in the United States. It is believed to be the fourth leading cause of disability in the w ...
References
External links
*
{{Congenital malformations and deformations of musculoskeletal system
Congenital disorders of musculoskeletal system
Knee injuries and disorders