ABSTRACT
INTRODUCTION: Tobacco use elevates the incidence of postoperative complications and remains a key modifiable risk factor of perioperative surgical optimization. It remains unclear whether non-tobacco nicotine dependence confers an increased risk of surgical complications. This study evaluates postoperative complications in patients with non-tobacco nicotine dependence for total knee arthroplasty (TKA). METHODS: We queried the TriNetX health database using Current Procedural Terminology and International Classification of Diseases, 10th Revision (ICD-10) codes and identified two cohorts for evaluation. Cohort A was defined as patients who had a TKA; had a dependence on nicotine; did not have nicotine dependence to cigarettes, chewing tobacco, other tobacco products; and were between the ages of 35 and 90 years. Cohort B was defined as patients who had a TKA but did not have a dependence on nicotine or a personal history of nicotine dependence and were between the ages of 35 and 90 years. RESULTS: This study analyzed a total of 10,594 non-tobacco nicotine-dependent patients and 175,079 non-dependent patients who underwent TKA. In the analysis of propensity-matched cohorts, non-tobacco nicotine-dependent patients demonstrated an increased rate of various postoperative complications within 90 days. Dependent patients saw a significantly increased risk of infection after a procedure (P < 0.001), deep vein thrombosis (P < 0.001), pulmonary embolism (P < 0.001), sepsis (P = 0.0065), and prosthetic joint infection (P = 0.0361) and a higher 3-year revision rate (P = 0.0084). DISCUSSION: Non-tobacco nicotine dependence demonstrated an increased associated risk of postoperative surgical complications for patients undergoing TKA. Orthopaedic surgeons should consider evaluating non-tobacco nicotine dependence within their surgical optimization protocol. LEVEL OF EVIDENCE: Level III, Prognostic.
ABSTRACT
BACKGROUND: Transcutaneous spinal stimulation (TSS) has become a valuable tool for facilitating rehabilitation in individuals with neurological deficits. A significant constraint arises from the need for precise knowledge of stimulation locations to effectively apply TSS for targeted functional enhancement. METHODS: In this study, we investigate whether single-site or simultaneous multi-site stimulation over the lumbar spinal cord is advantageous for recruitment of specific motor pools projecting to lower limb muscles and generates higher leg extensor forces in neurologically intact individuals. Tests were performed in a supine position. TSS was delivered at T10-T11, T11-T12, T12-L1, and L1-L2 intervertebral spaces individually, then through all four locations simultaneously. The peak-to-peak amplitude of spinally evoked motor potentials and the forces generated by lower limb muscles were compared at the common motor threshold intensity level across all stimulation conditions. RESULTS: Recruitment of motor pools projecting to proximal and distal lower limb muscles followed their topographical rostro-caudal arrangement along the lumbosacral enlargement. Single-site stimulation, apart from the T10-T11 location, resulted in larger responses in both proximal and distal muscles while also generating higher knee-extension and plantarflexion forces when compared to multi-site stimulation. CONCLUSIONS: Both motor response and force generation were reduced when using multi-site TSS when compared to single-site stimulation. This demonstrates that the segmental effects of TSS are important to consider when performing multi-site TSS.
