Hemihypertrophy (one side too big) and hemiatrophy (one side too small) are conditions that cause limb length discrepancy. In most cases they are not noticed by patients or physicians, but the impact on body function could be very significant.
Deformities associated with aging
Problems with vision
Problems with hearing
In many cases, anatomical SLD lead to functional SLD and vise versa
Even minimal asymmetry will induce compensatory (see oculo-cephalic reflex) response which with time becomes clinically significant. The compensatory response may occur in any part of the body, but most commonly in the area previously impacted by pathological process.
For instance: The unilateral reduction of the longitudinal arch of the foot will lead to Side Leg Discrepancy. Some may think 3-5 mm of the difference of leg’s length is not enough to cause the problem… But when compensatory response lasts for some period of time this condition will cause overuse injury of the group of muscle on one side of the back and cause chronic pain.(Allostatic response).
One of my patients was diagnosed with minimal idiopathic scoliosis during her puberty. The deformity was minimal and did not require treatment other than swimming exercises. She got married, become pregnant , and at the age of 28 delivered a normal baby.
During and after pregnancy there was no progression of scoliosis.
At the age of 35 she gradually starts to develop bilateral hallux valgus. She was unhappy with how her feet look and were advise elective surgery for correction of the deformities.
She decided to do one foot at the time. Unfortunately, surgery did not bring desirable results and a second surgery to correct residual deformity on the same foot was attempted and also was not successful. She decided to do nothing with another foot. As a result, the operated foot has now shorter longitudinal arch compare to non-operated foot, and therefore her left side ( operated foot) becomes shorter.
Gradually, over the next 4-5 years her scoliosis started to progress and at the age of 42 her Cobb angle was about 70 degrees.
She becomes very symptomatic: back, hips, neck pain; Various forms of conservative treatments were ineffective. Subsequently she had 8 (!) cervical, thoracic, lumbar and hip surgeries over the next 15 years. She became opioid-dependent and eventually died at the age of 59 from an accidental overdose.
The first image is a surgical correction of the hallux valgus at the age of 35;
Second and third images are done 24 years later shortly before her death.