Beyond the Knot: A Pragmatic Comparison of Monocryl and Prolene for Neurosurgical Wound Closure

Background Surgical site infection (SSI) is a major source of morbidity and additional cost following neurosurgical procedures. Although absorbable monofilament sutures (poliglecaprone 25 and Monocryl) and non-absorbable polypropylene sutures (Prolene) are both routinely used for skin closure, direct comparative data in mixed cranial and spinal neurosurgical cohorts remain limited, particularly from low- and middle-income settings. We compared Monocryl and Prolene for neurosurgical skin closure in a descriptive (nonequivalence) design. The primary outcome was SSI; secondary outcomes were skin closure time, length of hospital stay, and inpatient postoperative hospitalization cost. Methods This single-center retrospective cohort study included 523 adult patients (≥18 years) undergoing elective or emergency cranial or spinal neurosurgical procedures at a public-sector tertiary neurosciences institute between January 2024 and December 2025. Patients were grouped by skin closure material (Monocryl or Prolene). SSI was defined according to the United States CDC 2017 guideline. Continuous variables were compared using the Mann-Whitney U test and reported as mean ± SD and median with IQR; categorical variables were compared using the chi-square test or Fisher's exact test. Multivariable logistic regression was used to identify independent predictors of SSI. A two-sided p-value <0.05 was considered statistically significant. Results Of 523 patients (mean age 46.3 ± 16.6 years; 51.4% male), 221 (42.3%) underwent skin closure with Monocryl and 302 (57.7%) with Prolene. The overall incidence of SSI was 12.0%. SSI was numerically lower in the Monocryl group (9.5%) than in the Prolene group (13.9%), but this difference did not reach statistical significance (p = 0.126). There were no significant between-group differences in CSF leak, reoperation, or readmission rates. Skin closure time was significantly shorter with Monocryl than with Prolene (median 7 minutes, IQR 6-9 vs median 14 minutes, IQR 12-17; p < 0.001). Length of hospital stay (p = 0.125) and inpatient hospitalization cost (p = 0.170) did not differ significantly between groups. Multivariable logistic regression did not identify any independent predictors of SSI (model omnibus p = 0.136). The two groups differed significantly in procedure type (elective vs emergency; p < 0.001), indicating confounding by indication. Conclusions In this large neurosurgical cohort, we did not detect a statistically significant difference in SSI or other adverse postoperative outcomes between Monocryl and Prolene; however, the study was not designed or powered to establish equivalence, and the two groups were imbalanced by procedure type. Monocryl was associated with significantly faster skin closure, although this comparison also reflects a difference in closure technique between groups. These findings should be regarded as hypothesis-generating and warrant confirmation in adequately powered, indication-matched prospective studies.