Correlation between shape-closed femoral stem design and bone cement implantation syndrome in osteoporotic elderly femoral neck fracture undergoing cemented hip arthroplasty: A retrospective case-control study in 128 patients.

BACKGROUND: Bone cement implantation syndrome (BCIS) is a serious and potentially fatal complication especially in patients with osteoporotic femoral neck fracture (OFNF) undergoing cemented hip arthroplasty (CHA). Recent studies showed that the shape-closed femoral stem profile could lead to a significant increase of the intramedullary pressure during cementation and prosthesis insertion. This study aimed to (1) correlate the use of shaped-closed femoral stem and other perioperative risk factors with severe grade of BCIS grade 2 or 3: BCIS gr2/3, and (2) identify the prevalence of BCIS in the elderly patients with OFNF and treated with CHA. HYPOTHESIS: Large wedge-shaped (or "shape-closed") femoral stem design would significantly associate with BCIS gr2/3 in the elderly patients who sustained OFNF and underwent CHA. PATIENTS AND METHODS: A total of 128 OFNF patients, who aged over 75years and underwent CHA were retrospectively reviewed and then allocated into 2 groups: SC Group (use shape-closed femoral stem, n=40) and FC Group (use force-closed femoral stem, n=88). BCIS was grading in all patients according to Donaldson classification. Perioperative data between the patients with BCIS-gr2/3 and those with BCIS grade 0 or 1 (BCIS-gr0/1) were compared. Multiple logistic regression analysis was used to identify predictive factors for BCIS-gr2/3. RESULTS: The prevalence of overall BCIS and BCIS-gr2/3 was 32.8% (n=42) and 6.2% (n=8), respectively. The total in-hospital and 1-year mortality rates were 2.3% and 4.7%, respectively. The major perioperative complication in patients with BCIS-gr2/3 was significantly higher compared to those in patients with BCIS-gr0/1 (62.5% vs. 10.0%, p=0.001). Multivariate analysis showed that age>90years (OR=9.4, 95% CI: 1.4-62.9, p=0.02), preinjury Parker mobility score<4 (OR=48.8; 95% CI: 2.7-897.2, p=0.008) and shape-closed femoral stem used (OR=19.1; 95% CI: 1.8-204.5, p=0.01) were the significant independent predictors for BCIS-gr2/3 in these patients. CONCLUSION: BCIS in OFNF patients undergoing CHA is common and associates with a high major perioperative complication rate. Our initial hypothesis is validated as the patients at risk for BCIS-gr2/3 are those whose CHA procedures use a shape-closed femoral stem design and with extreme age, and having poor preinjury ambulatory status. Therefore, we recommended using cementless stem as the first option in OFNF. However, if CHA is needed, strict guideline for cement insertion should be followed with force-closed stem application to avoid the risk of BCIS-gr2/3. LEVEL OF EVIDENCE: III; retrospective case-control study.

Effects of Desflurane and Sevoflurane anesthesia on regulatory T cells in patients undergoing living donor kidney transplantation: a randomized intervention trial.

BACKGROUND: Volatile anesthetic agents used during surgery have immunomodulatory effects which could affect postoperative outcomes. Recognizing that regulatory T cells (Tregs) plays crucial roles in transplant tolerance and high peripheral blood Tregs associated with stable kidney graft function, knowing which volatile anesthetic agents can induce peripheral blood Tregs increment would have clinical implications. This study aimed to compare effects of desflurane and sevoflurane anesthesia on peripheral blood Tregs induction in patients undergoing living donor kidney transplantation. METHODS: A prospective, randomized, double-blind trial in living donor kidney transplant recipients was conducted at a single center, tertiary-care, academic university hospital in Thailand during August 2015 - June 2017. Sixty-six patients were assessed for eligibility and 40 patients who fulfilled the study requirement were equally randomized and allocated to desflurane versus sevoflurane anesthesia during transplant surgery. The primary outcome included absolute changes of peripheral blood CD4+CD25+FoxP3+Tregs which measured by flow cytometry and expressed as the percentage of the total population of CD4+ T lymphocytes at pre-exposure (0-h) and post-exposure (2-h and 24-h) to anesthetic gas. P-value < 0.05 denoted statistical significance. RESULTS: Demographic data were comparable between groups. No statistical difference of peripheral blood Tregs between desflurane and sevoflurane groups observed at the baseline pre-exposure (3.6 ± 0.4% vs. 3.1 ± 0.4%; p = 0.371) and 2-h post-exposure (3.0 ± 0.3% vs. 3.5 ± 0.4%; p = 0.319). At 24-h post-exposure, peripheral blood Tregs was significantly higher in desflurane group (5.8 ± 0.5% vs. 4.1 ± 0.3%; p = 0.008). Within group analysis showed patients receiving desflurane, but not sevoflurane, had 2.7% increase in peripheral blood Treg over 24-h period (p < 0.001). CONCLUSION: This study provides the clinical trial-based evidence that desflurane induced peripheral blood Tregs increment after 24-h exposure, which could be beneficial in the context of kidney transplantation. Mechanisms of action and clinical advantages of desflurane anesthesia based on Treg immunomodulation should be investigated in the future. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02559297 . Registered 22 September 2015 - retrospectively registered.