Handedness and spinal deformity

Area of Science:

• Orthopedics
• Neurology
• Epidemiology

Background:

• Biological lateralisation is observed in scoliosis, but its role remains unclear.
• Previous studies have yielded conflicting results regarding left-handedness as a risk factor for spinal deformity.
• The general population has a sinistrality (left-handedness) rate of approximately 10%.

Purpose of the Study:

• To investigate the association between sinistrality and clinically significant scoliosis.
• To determine if scoliosis lateralisation differs from population norms.
• To explore correlations between curve pattern and handedness in various scoliosis types.

Main Methods:

• A reassessment of a scoliosis database was performed.
• 1,636 patients with complete data were analyzed.
• Patients' preferred writing hand was recorded to determine handedness.

Main Results:

• Overall left-handedness occurred in 11.5% of patients, significantly higher than the general population (p=0.04).
• Increased left-hand preference was noted in boys with infantile idiopathic scoliosis and girls with infantile, juvenile, congenital, and syndromic scoliosis.
• Reduced left-handedness was observed in girls with adolescent idiopathic scoliosis; curve pattern and handedness correlations varied by scoliosis type and sex.

Conclusions:

• This study does not confirm left-handedness as a risk factor for spinal deformity.
• The incidence of left-handedness in scoliosis is not uniform and is reduced in certain groups, such as girls with adolescent idiopathic scoliosis.
• Scoliosis lateralisation is a factor but likely a consequence of the scoliotic process rather than a cause.