Incidence of pars defect associated with idiopathic scoliosis has been reported as 6% based on roentgenographic evaluation in previous studies. (Fisk et al, 1978). We aim to present our results in an MRI based study.

224 patients of adolescent idiopathic scoliosis (AIS) who had an MRI scan over a period of three years (2006-2008), performed either as a preoperative investigation or due to other symptoms were reviewed. All MRI scans were reviewed by two experienced musculoskeletal radiology consultants independently.

Among 224 patients 13 (5.8%) patients were found to have pars defect. Mean age-group of patients were (19 years, range-11-40). 84.6% (n=11) patients were female and 15.3% patients were male. There was varying severity of curve patterns. We have noted two lumbar/thoraco-lumbar curves (Lenke 5), King Type I-6, King Type II-2 and three King Type III curves. All scoliotic deformities were non-structural. Bilateral pars defect was noted in nine (69%) patients.

Previous studies (Fisk et al, 1978; Mau H 1981) have described the incidence of pars defect as approximately 6.2%. Recent studies have emphasized use of MRI to diagnose pars defect based on signal changes in the pedicle (Sairyo et al.). Our study reveals the incidence of pars defect in AIS to be 5.8 % based on MRI diagnosis which does not seem to be different to previous roentgenographic studies.

In major procedures like scoliosis surgery, parents are often asked to sign the consent on behalf of children because of the pretext that minor may have limited understanding and judgement about the procedure. Scoliosis surgery for patients with AIS is mainly indicated for cosmetic or psychological reasons.

We audited our practice in the department to collect information on the current consent practices involving the minor patients undergoing scoliosis surgery.

We also have conducted a questionnaire survey of the various spinal units in UK to assess their practice in this regard.

Forty-two consent forms (28 patients; multiple procedures in some patients) and case notes of patients between 12 and 16 years undergoing scoliosis surgery were reviewed. We have contacted 12 spinal deformity correction units and 11 spinal trauma units across UK over telephone to assess the current consenting practice as well.

9.5% (n=4) patients signed there own consent forms. Except in one case explanation of risks were documented in detail. Except two units (18%) offering the minor patient to sign their consent, parents are usually asked to sign consent on their behalf in majority (10/12) units. Seven out of the twelve spinal units use standard NHS or department of health consent forms. Few units have their own consent form with some alterations or additions.

There is no specific age when a child becomes competent to consent to treatment: It depends both on the child and on the seriousness and complexity of the treatment being proposed. However, it is still good practice to encourage competent children to more involved along with their families in decision-making.