Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) are common complications following total knee arthroplasty (TKA) and total hip arthroplasty (THA), affecting the length of hospital stay and increasing medical complications. Although many papers have been published on both conditions in this setting, no reviews have currently been written. Thus, the purpose of our study is to summarize the current literature and provide information about POD and POCD following elective THA or TKA. Our literature search was conducted in the electronic databases PubMed and the Cochrane library. We found that POD is a common complication following elective THA or TKA, with a median incidence of 14.8%. Major risk factors include older age, cognitive impairment, dementia, preoperative (pre-op) comorbidities, substance abuse, and surgery for fracture. Diagnosis can be achieved using tools such as the confusion assessment method (CAM), which is sensitive, specific, reliable, and easy to use, for the identification of POD. Treatment consists of risk stratification and the implementation of a multiple component prevention protocol. POCD has a median incidence of 19.3% at 1 week, and 10% at 3 months. Risk factors include older age, high BMI, and cognitive impairment. Treatment consists of reversing risk factors and implementing protocols in order to preserve physiological stability. POD and POCD are common and preventable complications following TKA and THA. Risk stratification and specific interventions can lower the incidence of both syndromes. Every physician involved in the care of such patients should be informed on every aspect of these conditions in order to provide the best care for their patients.

Background: Externally controlled intramedullary lengthening nails (IMNs) have reduced the soft-tissue morbidity associated with external fixation. However, these complex devices introduce specific risks related to their motorized and telescopic mechanisms. Existing literature often conflates structural fatigue fractures with internal mechanism dysfunction. This systematic review aims to analyze the incidence, etiology, and management of intrinsic mechanism failures in lengthening IMNs. Methods: A comprehensive search of PubMed, Embase, and Scopus was conducted from January 2000 to July 2025 in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. The review included human studies reporting mechanism-related failures (e.g., jamming, backtracking, and motor failure) in externally controlled IMNs. Studies describing only structural fatigue fractures or nonexternally controlled devices were excluded (e.g., Intramedullary Skeletal Kinetic Distractor [ISKD]). Data were stratified by implant generation and material. Results: Twenty-nine studies encompassing 2,495 nails were included. The overall reported mechanism-related failure rate was 4.3% (n = 107/2,495). Distinct failure phenotypes emerged based on the implant material. Titanium-alloy nails (PRECICE P1/P2) demonstrated a 4.2% failure rate (n = 74/1,761), predominantly characterized by mechanical jamming or gear slippage due to load-induced yield. Stainless steel nails (STRYDE) exhibited a significantly higher failure rate of 12.9% (n = 12/93), primarily driven by tribocorrosion and biological reactions at the telescopic junction. The FITBONE system had a reported failure rate of 3.3% (n = 21/641). Management required surgical intervention in 97.2% of failure cases, with exchange nailing being the primary salvage strategy (94.4%). Despite the need for reoperation, the target limb length was reportedly achieved in the majority of studies where quantitative outcomes were specified. Conclusion: Mechanism failure in externally controlled lengthening IMNs is a clinically significant complication with a reported incidence of approximately 1 in 24 cases. A material trade-off is evident: Titanium implants are susceptible to mechanical gear yield, whereas stainless steel implants are prone to tribocorrosion-induced failure. While these failures necessitate revision surgery, they typically do not preclude successful limb reconstruction if managed with timely nail exchange. Level of Evidence: Level III . See Instructions for Authors for a complete description of levels of evidence.

Objectives: Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive neuromodulation technique with emerging applications in various medical fields. While its role has been explored in neurological, psychiatric, and inflammatory conditions, its potential in orthopedics has not been reviewed in depth. Our objective was to synthesize current evidence on the use of taVNS in orthopedic conditions. Methods: A PubMed search was conducted for articles published between January 2010 and July 2025 using the terms “transcutaneous” AND “vagus nerve” AND “stimulation.” Seventeen eligible studies were identified after applying predefined inclusion and exclusion criteria. Randomized controlled trials were assessed for methodological quality using the Risk of Bias 2 tool. Results: Seventeen studies addressed the orthopedic applications of taVNS for chronic low back pain, neck pain, knee osteoarthritis, and in perioperative settings. Across the included studies, taVNS was associated with reductions in pain intensity, although superiority over control interventions was not consistent across trials; additional potential benefits were reported for sleep quality, disability indices, and psychological measures. In perioperative contexts, high-quality randomized trials demonstrated reductions in postoperative pain and analgesic requirements. However, methodological heterogeneity, small sample sizes, and inconsistent stimulation protocols limit the strength of the conclusions. Discussion: taVNS is a safe, accessible, and promising adjunctive therapy for pain management in orthopedics, with potential applications in both chronic and perioperative settings. Larger, high-quality trials are required to establish standardized protocols and clarify clinical efficacy.