Preoperative Prevalence and Risk Factors For Calf Muscular Vein Thrombosis in Elderly Patients with Hip Fracture.

OBJECTIVE: Increasing evidence has shown that calf muscular vein thrombosis (CMVT) can develop into proximal deep vein thrombosis, even causing pulmonary embolism. However, opinions about the prevalence and risk factors are still controversial. This study aimed to investigate the prevalence and risk factors for CMVT in elderly patients with hip fractures to facilitate their preoperative management. METHODS: We included 419 elderly patients with hip fracture who were treated in the orthopaedic department of our hospital from June 2017 to December 2020. The patients were divided into CMVT and non-CMVT groups based on color Doppler ultrasound screening of the venous system in the lower extremities. Clinical data, such as age, sex, body mass index, time from injury to admission, and laboratory data were collected. Univariate and multivariate logistic regression analyses were performed to determine independent risk factors for CMVT. A receiver operating characteristic curve was used to analyze the predictive effectiveness of the model. Finally, the clinical utility of the model was analyzed using decision curve analysis and clinical impact curves. RESULTS: The prevalence of preoperative CMVT was 30.5% (128/419). Independent predictors of preoperative CMVT identified by univariate and multivariate logistic regression analyses were sex, time from injury to admission, American Society of Anesthesiologists (ASA) classification, C-reactive protein (CRP) level, and D-dimer level (p < 0.05). The area under curve (AUC) was 0.750 (95% CI: 0.699-0.800, p < 0.001) and the sensitivity and specificity were 0.698 and 0.711, respectively, which meant the prediction model has a good efficacy in the prediction of CMVT risk. In addition, the fitting degree of the prediction model was also good (Hosmer-Lemeshow χ2 = 8.447, p > 0.05). The clinical utility of the model was verified using decision curve analysis and clinical impact curves. CONCLUSION: Sex, time from injury to admission, ASA classification, CRP level, and D-dimer levels are independent preoperative predictors of CMVT in elderly patients with hip fractures. Measures should be taken for patients with these risk factors to prevent the occurrence and deterioration of CMVT.

Intraindividual variance of lower limb rotation in patients with bilateral knee osteoarthritis.

Purpose: To determine the side-to-side difference in intraindividual rotation alignment of patients with bilateral varus-type knee osteoarthritis (OA) and compare it with control subjects. Methods: This retrospective study enrolled 60 patients with bilateral varus-type knee OA and 50 control subjects. All cases underwent bilateral lower limb CT angiography. Bilateral femoral and tibial rotation alignment were measured, and the overall lower limb rotation was calculated by two different methods. Method 1 was calculated by subtracting angle of the femoral torsion from the tibial torsion and method 2 was determined by relative rotation of the femoral neck angle to bimalleolar angle. The intraindividual variance and differences between the two groups were analyzed. Results: Both OA and control samples showed significant differences between right and left for all measurements. Femoral torsion for control group was 10.4 ± 5.5°, tibial torsion was -22.1 ± 6.1°, and overall leg rotation by method 1 was -15.6 ± 7.2° and method 2 was -11.7 ± 8.2°. Femoral torsion, tibial torsion, method 1, and method 2 in the patients with OA were 8.2 ± 6.3°, -18.6 ± 4.1°, -14.9 ± 7.9°, and -10.4 ± 7.6°, respectively. Patients with OA showed a more pronounced retroversion in the femur (p = 0.008) and more internal rotation in the tibia (p < 0.001). No statistical significance of both methods was found between the two groups. Patients with OA had a greater median side-to-side absolute difference in all measurements, though the differences of both two methods of overall lower limb rotation were not statistically significant. Conclusions: The discrepancy of side-to-side differences of bilateral lower limb rotation ought to be noticed with caution in diagnosing and treating rotational deformities of the lower limb, especially for patients with bilateral knee OA.