Risk factors for hypertrophic scar

Postoperative neck scarring is a major concern for patients who undergo thyroid surgery; however, the treatments for hypertrophic scars are generally considered by patients to provide unsatisfactory outcomes. Therefore, risk factors should be identified and prevention of these factors is considered to be critical in management. We reviewed the medical records of 96 thyroidectomy patients who were divided into two groups based on scar type: patients with hypertrophic (n = 61) and linear flat scars (n = 35). Multivariable logistic regression model was developed to identify risk factors for developing hypertrophic scar. There was no significant difference between the two groups in terms of age, gender ratio, tumor type, and type of operation. Multivariable analysis showed that hypertrophic scar development was associated with scars located within 1 cm above the sternal notch (odds ratio [OR] = 5.94, p = 0.01), prominent sternocleidomastoid muscles (OR = 12.03, p < 0.01), and a high body mass index (OR = 1.33, p = 0.01). The area under the receiver operating characteristic curve for risk factors was 0.85. Development of hypertrophic scar after thyroidectomy was found to be associated with specific preoperative factors such as incision site near the sternal notch, prominent sternocleidomastoid muscles, and high body mass index.