INTRODUCTION

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:

 

  1. Frontal plane: varus and valgus deformities
  2. Transverse plane: torsional problems
  3. Sagittal plane: recurvatum (extension deformities) and flexum (flexion deformities)

FRONTAL PLANE

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 ).

  • Genu Valgum (left), Genu Varum (right)

    Genu Valgum (figure 1), Genu Varum (figure 2)

    Supination/pronation:

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).

 

TRANSVERSE PLANE

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. 
    • 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.

 

SAGITTAL PLANE

The sagittal plane represents the left and right sides of the body. Affected areas in the sagittal plane include:

  • Flexor/extensor
    • 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.
  • Procurvatum/recurvatum
    • 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.

 

POSITION

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).

 

Pictures from left to right: 1) 20° genu recurvatum (knee recurvatum); 2) In standing front position, it may mimic a genu varum (knee varus); 3)When the recurvatum is corrected with knee extension at 0°, the genu varum corrects by itself: it is so far a false genu varum which does not need correction in itself; 4) On X-rays, the origin of the genu varum is observed: proximal tibial recurvatum of 10° (angle B at 90° instead of 80°), and a 10° joint recurvatum (laxity in the joint). A tibial bony correction will correct in a great par the deformity.

Pictures from left to right: 1) 20° genu recurvatum (knee recurvatum) 2) In standing front position, it may mimic a genu varum (knee varus) 3)When the recurvatum is corrected with knee extension at 0°, the genu varum corrects by itself 4) On X-rays, the origin of the genu varum is observed: proximal tibial recurvatum of 10° (angle B at 90° instead of 80°), and a 10° joint recurvatum. A tibial bony correction will correct a great part of the deformity.

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.