Bone deformities can be congenital (present from birth) or hereditary (genetically carried), but also occur during growth or after severe physical trauma. Some bone disorders can show no symptoms, whilst others cause pain and difficulties walking.
In cases of child deformity, diagnosis and treatment should be evaluated with caution as there is a risk of residual growth, as a deformity can get better or worsen as the child grows.
The occurrence of bone deformities can be found in the three main planes of the body:
- Frontal plane: varus and valgus deformities
- Transverse plane: torsional problems
- Sagittal plane: recurvatum (extension deformities) and flexum (flexion deformities)
The frontal (or coronal) plane is an example of a longitudinal plane and refers to front and back of the body. Defects can occur through:
- Varus and valgus deformity
This is the joint angulation disorder that generally affects the knee. Varus knees have an inward angulation, which produce an ‘O’ shape stance, otherwise known as bowlegged (see figure 1), whilst Valgus knees, an outward joint angulation, result in an ‘X’ shape or knock-kneed appearance (see figure 2 ).
These are deformities to the hand or foot. There is a reduction is hand supination (the ability to turn the hand upwards) and pronation (seizing or grasping).
The transverse plane is the horizontal plane that divides the upper and lower body. Deformities in this plane include:
- External/internal rotation.
- This is the inward and outward rotation of two different bones, such as foot joints, which turn in an internal (towards the body) or external (moves away from the body) rotation. Excessive rotation causes strain to the joints and stretches the ligaments and tendons.
- Torsion is a rotatory motion within a single bone. Excessive torsion is where the rotation between the upper and the lower sections of the bone is greater than the normal, for example, excessive femoral torsion.
The sagittal plane represents the left and right sides of the body. Affected areas in the sagittal plane include:
- These involve the position of two bones. Flexor (the flexion) is the ability to bend backwards, whilst extensor is the forward bending and extension. However, if these are deformed, the movement is restricted and full extension cannot be achieved.
- This refers to the movement of a single bone; where a procurvatum deformity describes backward bending of the bone and recurvatum deformity is the forward bending of the bone.
Positions of these deformities can occur at:
- Joint level, preventing full extension and motion.
- Bone level, which can be noticed at the epiphysis (rounded joint), the diaphysis (the bone shaft) or the metaphysis (between epiphysis and diaphysis, known as the growth plate).
COMBINATION OF SEVERAL BONE DEFORMITIES
In some cases, multiple bone deformities can affect the same bone or joint. It is possible for a custom-made program to be used on multiple bone deformities which would address bone, joint and soft-tissue damage. Corrections should, when possible, be performed at the level of the deformity to allow for a full correction.