Factors associated with trigger digit following carpal tunnel release

BACKGROUND Trigger digit is a common disorder of the hand associated with carpal tunnel syndrome. Carpal tunnel release (CTR) surgery may be a risk factor for trigger digit development; however, the association between surgical approach to CTR and postoperative trigger digit is equivocal. AIM To investigate patient risk factors for trigger digit development following either open carpal tunnel release (OCTR) or endoscopic carpal tunnel release (ECTR). METHODS This retrospective chart analysis evaluated 967 CTR procedures from 694 patients for the development of postoperative trigger digit. Patients were stratified according to the technique utilized for their CTR, either open or endoscopic. The development of postoperative trigger digit was evaluated at three time points: within 6 mo following CTR, between 6 mo and 12 mo following CTR, and after 12 mo following CTR. Firth's penalized likelihood logistic regression was conducted to evaluate sociodemographic and patient comorbidities as potential independent risk factors for trigger digit. Secondary regression models were conducted within each surgical group to reveal any potential interaction effects between surgical approach and patient risk factors for the development of postoperative trigger digit. RESULTS A total of 47 hands developed postoperative trigger digit following 967 CTR procedures (4.9%). In total, 64 digits experienced postoperative triggering. The long finger was most commonly affected. There was no significant difference between the open and endoscopic groups for trigger digit development at all three time points following CTR. Furthermore, there were no significant independent risk factors for postoperative trigger digit; however, within group analysis revealed a significant interaction effect between gender and surgical approach (P = 0.008). Females were more likely to develop postoperative trigger digit than males after OCTR(OR = 3.992), but were less likely to develop postoperative trigger digit than males after ECTR (OR = 0.489). CONCLUSION Patient comorbidities do not influence the development of trigger digit following CTR. Markedly, gender differences for postoperative trigger digit may depend on surgical approach to CTR.