Aetiology and Clinical Presentation of Windswept Deformity in Ghanaian Children

Windswept deformity is a malalignment of the knees characterised by unilateral valgus and contralateral varus. Only a limited number of studies have investigated the aetiology of windswept deformity. Most windswept cases in the literature are ancillary findings in studies or case reports. Typically, the causes of windswept deformity are classified into the following groups: 'rickets and other metabolic disorders', 'skeletal dysplasia and other genetic causes', 'trauma' and 'idiopathic conditions'.

After retrospectively reviewing patient files and radiographs, 23 patients with windswept deformity seen in a rural hospital in Ghana (between January 2017 and June 2022) were included. Data were collected through medical records, history taking, physical examination, and radiographs. Laboratory tests were carried out in 11 patients.

In most of the patients, windswept deformity developed shortly after the onset of walking (70% started within 6 months after walking); it started with unilateral valgus, which was later followed by contralateral varus (65%), and most patients had a normal weight (mean BMI 16.8, 51.7th percentile). A significant difference in mean BMI was observed when arm span was used instead of height (mean BMI: 15.8 ± 3.2 and 16.8 ± 4.0, respectively). The most common underlying condition was rickets (74%). Other causes include dysplastic (multiple epiphyseal dysplasia and unilateral Blount's disease), post-traumatic (distal femur fracture), and idiopathic factors. Laboratory tests in 8 of the 11 patients showed vitamin D insufficiency.

This study suggests that windswept deformity in young children usually develops with an initial valgus position, which is followed by contralateral varus. Rickets was the most frequently identified underlying diagnosis, with vitamin D insufficiency commonly observed among tested patients.