Discussion
inflammation, scars, pain, tightness, tenderness, carpal tunnel
SCAR, INFLAMMATION, ADVERSE REACTION, PROLIFERATIVE, SCAR, COMPLICATIONS
Although carpal tunnel release is the most performed elective procedure in the hand, debate remains regarding the optimal suture type and method for wound closure. There is emerging evidence that suture material and closure technique can influence the ultimate outcome (Several studies have pointed to the advantages conferred by using absorbable sutures for closure of carpal tunnel incisions. Two groups found that patients who received absorbable sutures had significantly less pain in the immediate postoperative period compared with patients who received non-absorbable sutures (Prior economic analyses have suggested that use of absorbable sutures offers a significant opportunity for cost reduction. A Cochrane report determined that if all surgeons in the United Kingdom used non-absorbable sutures after carpal tunnel release, then the cost to the healthcare system for a nursing visit to remove sutures would be over 3 million British pounds (GBP) per year (Prior studies have highlighted potential drawbacks of absorbable sutures, namely increased residual wound inflammation and persistent scar tenderness (We found no differences in patient or observer assessment of any category between the Monocryl or nylon groups at 6 weeks, although our study was underpowered to reveal if there actually would be a difference in observer ratings at this timepoint. No patient in our study developed a delayed adverse reaction to Monocryl. No patients developed any surgical site complications. This suggests that delayed tissue reaction or inflammation is not a major concern at 6 weeks following Monocryl use and that absorbable and non-absorbable sutures produce comparable scars in the long-term. Furthermore, our findings challenge the classic teaching that non-absorbable sutures cause less inflammation and therefore result in a better scar. Scar appearance following Monocryl (a) and nylon (b) wound closures immediately postoperative and at 2 weeks.Our study has limitations. Based on our a priori power analysis, our study was underpowered to detect a difference in patient and observer scar assessment scales between Monocryl and nylon at 6 weeks. However, it is our experience and impression while conducting this study that the majority of patients in both groups were fully healed by 6 weeks with only minimally noticeable difference in their scars. Indeed, many patients questioned the need for the 6-week postoperative appointment, and only 62 of the 104 patients returned to complete the 6-week study visit. We do not believe that those patients lost to follow-up would bias our results, as they likely had satisfactory healing of their scars, which would reinforce the findings that no major differences exist between Monocryl and nylon closures at 6 weeks and that similar long-term outcomes can be expected regardless of suture type or closure technique. Recruiting an additional 83 patients to power the study to detect a difference in observer scar ratings at 6 weeks did not seem like a practical endeavour. Importantly, we did find statistically significant differences between Monocryl and nylon at 2 weeks. When statistical tests are significant, it is always of sufficient power, and thus we can reject our null hypothesis that Monocryl and nylon would produce equal POSAS scores at 2 weeks. Another limitation is that we were unable to perform a multivariate analysis of other surgical variables that might have influenced scar appearance (e.g. time to suture removal, tightness of closure). A final limitation is that 6 weeks may be considered a relatively short follow-up period. However, we anticipated that because most wounds would be fully healed at this stage, it would be challenging to have patients return several months later beyond the normal follow-up period for a carpal tunnel release, which did turn out to be the case. Furthermore, at 6 weeks wounds are nearing the end of the proliferative healing phase before remodelling, and thus any differences between groups would be best highlighted in the period leading up to this timepoint (