Chronic Local Injected Corticosteroid Use Increases Likelihood of Postoperative Morbidity Following Median Nerve Decompression for Carpal Tunnel Syndrome

Dear Editor,

Carpal tunnel syndrome occurs due to entrapment of the median nerve by the transverse carpal ligament and is the most common entrapment neuropathy in the United States. ¹ The purpose of our investigation was to identify preoperative factors that increased the odds of developing postoperative surgical site complications in a large group of patients undergoing treatment for carpal tunnel syndrome.

To answer the research question, we implemented a cross-sectional study of consecutive median nerve decompressions reported to the American College of Surgeons National Surgical Quality Improvement Program database over a 15-year period. Our institution did not require IRB approval for this de-identified, population-based, retrospective descriptive study. Predictor variables of interest included: age, sex, obesity, and medical comorbidities (diabetes mellitus, smoking, chronic obstructive pulmonary disease [COPD], hypertension, local steroid use). The primary outcome was 30-day postoperative surgical site complication rates, including surgical site infections and wound dehiscence. To identify independent factors associated with our primary outcome, we first performed a univariate analysis to compare patient cohorts (χ² test and the Fisher exact test for categorical variables, the Mann-Whitney U test for nonparametric continuous variables, and the independent samples t test for parametric continuous variables). We then constructed a multivariate logistic regression model. Our dependent variable was the rate of surgical site-related complications, and all predictor variables were included as possible independent covariates.

A total of 1305 patients with a mean age of 56.7 (±14.4) years were included in the study. Most (844/1305; 64.7%) were female. The mode of surgery was endoscopic in 9.2% (n = 121) of cases. The mean (±SD) body mass index (BMI) was 32.3 (±8.3), and 16.6% (n = 217) of patients had a history of smoking. Twenty (20/1305; 1.5%) patients experienced a surgical site-related complication and reached the primary outcome. The most common surgical site-related complication was superficial surgical site infection (15/1305; 1.15%). History of presurgical local steroid therapy (odds ratio [OR]: 5.30, 95% CI: 1.20-8.70, P = .034) and COPD (OR: 5.20, 95% CI: 1.60-9.20, P = .014) were both independently associated with an increased odds of experiencing a postoperative surgical site-related complication (Table 1). No other predictor variables were associated with increased odds of postoperative surgical site-related complications.

Table 1.

Odds Ratios of Surgical Site-Related Complication After Nerve Decompression Surgery.

Variable	Odds ratio	95% confidence interval	P value
COPD	.2	1.6-9.2	.014a
Presurgical local steroid use	.3	1.2-8.7	.034a

Abbreviation: COPD, chronic obstructive pulmonary disease.

^a

P value of <.05 considered significant.

Optimal long-term management of carpal tunnel syndrome is valuable. Initially, patients are often managed conservatively with splinting, nonsteroidal anti-inflammatory drugs (NSAIDs), and local corticosteroid injections. Although helpful for reducing inflammation and carpal tunnel symptoms, local steroid injections within 30 days of surgery may come at the expense of impaired local wound healing after surgery, possibly increasing the risk of SSI, wound complications, and 1-year reoperation. ² Our study found a similar increased odds of postoperative surgical site-related complication after nerve decompression surgery in patients with presurgical steroid use; however, here steroid use was not limited to 30 days preoperatively. Interestingly, conventional preoperative risk factors, such as smoking, diabetes, and obesity were not associated with increased odds of postoperative surgical site-related complications, but a history of severe COPD was associated. This may represent a future direction of study.