A Cochrane review included 24 trials with 2826 participants on surgical treatments for ingrowing toenails. Five studies were on non-surgical interventions, and 19 were on surgical interventions.
Surgical interventions were better at preventing recurrence than non-surgical interventions with gutter treatment (or gutter removal), and they were probably better than non-surgical treatments with orthonyxia (brace treatment). In 4 of the 12 studies in which a surgical intervention with chemical ablation (e.g. phenol) was compared with a surgical intervention without chemical ablation, a significant reduction of recurrence was found. The surgical interventions on both sides in these comparisons were not equal, so it is not clear if the reduction was caused by the addition of the chemical ablation. In only one study, a comparison was made of a surgical intervention known as partial nail avulsion with matrix excision compared to the same surgical intervention with phenol. In this study of 117 participants, the surgical intervention with phenol was significantly more effective in preventing recurrence than the surgical intervention alone (14% compared to 41% respectively, RR 0.34, 95% CI 0.17 to 0.69). None of the postoperative interventions described, such as the use of antibiotics or manuka honey; povidone-iodine with paraffin; hydrogel with paraffin; or paraffin gauze, showed any significant difference when looking at infection rates, pain, or healing time.
The studies had to have a minimum follow-up period of 6 months and had to aim to permanently remove the troublesome portion of the nail. Five studies compared phenolization with surgical removal. Phenolization with simple avulsion of the nail is more effective than the use of more invasive excisional surgical procedures in preventing symptomatic recurrences at 6 months or later on (46/352 versus 82/367, OR 0.44, 95% CI 0.24 to 0.80). In one study, the addition of phenol, when performing a total or partial nail avulsion, dramatically reduced the rate of symptomatic recurrence (OR 0.07, 95% CI 0.04 to 0.12). This was offset by a significant increase in the rate of postoperative infection when phenol was used (OR 5.69, 95% CI 1.93 to 16.77). However, the patients who underwent phenolization were more satisfied with their treatment than those who were treated with avulsion without phenolization.