Malnutrition Assessed Using the Geriatric Nutritional Risk Index Is Associated with Preoperative Incidence of Deep Vein Thrombosis in Japanese Patients Undergoing Total Knee Arthroplasty

Purpose: Few studies have evaluated the association between malnutrition and the risk of preoperative deep vein thrombosis (DVT) in patients undergoing primary total joint arthroplasty. This study aimed to investigate the prevalence of preoperative DVT in Japanese patients undergoing total knee arthroplasty (TKA) and the importance of malnutrition in the risk of preoperative DVT. Methods: We retrospectively analyzed 394 patients admitted for primary TKA at our institution between January 2019 and December 2023. All patients scheduled for TKA at our institution had serum D-dimer levels measured preoperatively. Lower-limb ultrasonography was examined to confirm the presence of DVT in patients with D-dimer levels ≥ 1.0 µg/mL or who were considered to be at high risk of DVT by the treating physician. Based on the results of lower-limb ultrasonography, all patients were divided into the non-DVT and DVT groups. The incidence of and risk factors for preoperative DVT were investigated, as well as the correlation of DVT with the patient’s nutritional parameters. We used two representative tools for nutritional assessment: the Geriatric Nutritional Risk Index (GNRI) and Controlling Nutritional Status Score. Results: The mean age was 77.8 ± 6.9 years. Preoperative DVT was diagnosed in 57 of the 394 (14.5%) patients. Multivariate logistic regression analysis showed that advanced age and malnutrition status, assessed using the GNRI, were independent risk factors for preoperative DVT. Conclusion: A high incidence of preoperative DVT was observed in patients who underwent TKA. Malnutrition status, as assessed using the GNRI, increased the risk of preoperative DVT. Our findings suggest that clinicians should consider these factors when tailoring preventive strategies to mitigate DVT risk in patients undergoing TKA.

Malnutrition and Its Association with the Mortality of Patients with Femoral Intertrochanteric Fractures: A Retrospective Analysis of Japanese Patients

Background: The incidence of femoral intertrochanteric fractures in older adults is higher than that of femoral neck fractures;however, both conditions are often analyzed together as proximal femoral fractures. Considering the difference in treatment, postoperative complication, and mortality risk, these two fractures should be analyzed separately. This study aimed to analyze 1-year mortality and its risk factors in patients with surgically treated femoral intertrochanteric fractures. Methods: Consecutive patients with intertrochanteric fractures who underwent surgical interventions at our institution between January 2017 and December 2021 were retrospectively reviewed. A total of 238 patients were eligible for inclusion in this study. Patients’ demographic and clinical information were retrospectively collected. Patients were divided into the 1-year mortality (n = 16) and survival (n = 222) groups. The incidence of 1-year mortality and its independent risk factors were investigated using univariate and multivariate logistic regression analyses. Results: The mean age of patients was 85.6 ± 8.5 years. The 1-year mortality rate was 6.7% (16/238). Preoperative albumin level, the Geriatric Nutritional Risk Index (GNRI), and malnutrition status (GNRI p = 0.02, p = 0.02, and p = 0.0011, respectively). Multivariate analysis showed that malnutrition status (GNRI p = 0.035) was an independent risk factor for 1-year mortality. Conclusion: Malnutrition status assessed using GNRI (GNRI < 92) was an independent risk factor for 1-year mortality. Our findings suggest that GNRI may be an effective screening tool for predicting postoperative 1-year mortality of patients with surgically treated femoral intertrochanteric fractures.

SOC Turnover and Lime-CO₂Evolution during Liming of an Acid Andisol and Ultisol

Agricultural liming contributes significantly to atmospheric CO2 emission from soils but data on magnitude of lime- contributed CO2 in a wide range of acid soils are still few. Data on lime-contributed CO2 and SOC turnover for global acid soils are needed to estimate the potential contribution of agricultural liming to atmospheric CO2. Using Ca13CO3 (13C 99%) as lime and tracer, here we separated lime-contributed and SOC-originated CO2 evolution in an acidic Kuroboku Andisol from Tanashi, Tokyo Prefecture (35°44′ N, 139°32′ E) and Kunigami Mahji Ultisol of Nakijin, Okinawa Prefecture, Japan (26°38′ N, 127°58′ E). On the average, lime-CO2 was 76.84% (Kuroboku Andisol) and 66.36% (Kunigami Mahji Ultisol) of overall CO2 emission after 36 days. There was increased SOC turnover in all limed soils, confirming priming effect (PE) of liming. The calculated PE of lime (Kuroboku Andisol, 51.97% - 114.95%;Kunigami Mahji Ultisol, 10.13% - 35.61%) was entirely 12C turnover of stable soil organic carbon (SOC) since SMBC, a labile SOC pool, was suppressed by liming in our experiment. Our results confirmed that mineralization of lime-carbonates is the major source of CO2 emission from acid soils during agricultural liming. Liming can influence the size of CO2 evolution from agricultural ecosystems considering global extent of acid soils and current volume of lime utilization. We propose the inclusion of liming in simulating carbon dynamics in agricultural ecosystems.

Natural Postoperative Bone Metabolic Changes after Total Knee Arthroplasty Determined by Positron Emission Tomography Scans

Artificial joint replacement surgery is the orthopedic procedure of choice to relieve pain, correct joint deformities, and help patients resume everyday activities. However, the detailed mechanisms regulating peri-implant bone remodeling at the bone-prosthesis interface remain elusive. To address this gap in knowledge, we evaluated the natural postoperative course of bone metabolism by using [18F] NaF positron emission tomography (PET)/computed tomography in 57 patients (104 joints) who underwent asymptomatic total knee arthroplasty (TKA). First, we measured total tracer uptake around TKA to determine the total bone metabolism (TBM) and used the ischial tuberosity as the reference tissue for normalization of PET images. Second, we calculated the TBM ratio (TBMR) by dividing the TBM by tracer uptake in the reference tissue. A moderate increase in TBMR was observed 4 - 5 days after implantation, and its intensity reached the maximum on the seventh postoperative day. The TBMR showed no differences until 12 weeks, after which it decreased slowly and returned to the basal levels. The new parameter TBMR and the unique pattern of postoperative metabolic changes in the bone around the prosthesis may help set accurate interpretation criteria to diagnose complications such as loosening or infections.