Femoral component rotation (FCR) is one of the most important factors in total knee arthroplasty. In this prospective study, we used three different techniques for FCR and analyzed their accuracy with postoperative axial computed tomography (CT) images. We also evaluated effect of FCR to clinical outcome. One hundred sixty-five patients were randomly allocated into three groups. In the measured resection group, FCR was set by externally rotating the axis 3° off the posterior femoral condylar axis. In the tensor group, a gap-tensioning device set at 20 lbf was used. In the block group, spacer blocks of various thicknesses were used. The FCR angle (FCRa) was measured on postoperative axial CT as an angle between the clinical transepicondylar and posterior condylar axes of the femoral component. Outliers were defined as FCRas deviated more than 3° either internally or externally. Postoperative 2 year clinical scores and knee range of motion were checked. The tensor group had significantly better positioning of the femoral component to the neutral position compared with the measured resection group and the block group (mean FCRa: internal rotation 1.79, 0.43 and 2.63°, respectively, p < 0.001). The outliers were also least frequent in the tensor group (35, 16 and 40%, respectively, p = 0.02). There were no significant differences in postoperative 2 year clinical results among groups. Gap technique with a 20-lbf tensor device was the most accurate and precise method for obtaining adequate FCR. Measured resection with 3° external rotation and gap technique with blocks could lead to internal rotation of the femoral component. Postoperative 2 year clinical results were not significantly different among groups with different techniques for FCR. The study was registered in the Clinical Research information Service (trial number: KCT0000129 ) in Korea. Registration date is 23rd of June, 2011.

Meniscus horizontal tears are usually degenerative. It could be asymptomatic and unrelated to knee symptoms. Therefore, there are controversies regarding treatment choices. The aim of this study was to evaluate factors that affect the results of non-surgical and surgical treatments for meniscus horizontal tears. We retrospectively studied 159 patients with meniscus horizontal tears with a minimum 2-year follow-up period. Patients were treated non-surgically or arthroscopically. The treatment results were dichotomized into success and failure. The factors considered were age, sex, joint line tenderness, mechanical symptoms, widest tear gap width on sagittal MRI, cartilage lesion grade, discoid meniscus, tear site, and joint alignment. Joint alignment and cartilage lesion grade were the factors that significantly influenced non-surgical treatment results. The widest tear gap width and cartilage lesion grade significantly affected arthroscopic surgery results. The mechanical symptoms did not show any significant relationship with either treatment result. In treating patients with meniscus horizontal tears, patients with varus alignment and advanced cartilage lesions should be informed of possible poor outcomes with non-surgical treatment. If the patient has a wide tear gap or minimal cartilage lesion, arthroscopic surgery would be a good treatment choice. The mechanical symptom was not an adequate factor for arthroscopic surgery.

Mortality rates and causes of death after total knee arthroplasty (TKA) are of great interest to surgeons. However, there is a shortage of studies regarding those of the Asian population. The aim of this study was to compare the mortality rate and causes of death in patients after TKA to the general population. National sample cohort data from the Korean Health Insurance Review and Assessment Service were used. In this study, 1:4 matched patients after TKA (TKA group: 5072) and general participants (control group: 20,288) were selected as subjects. Their average follow-up duration was 57.2 months ranging from a year up to 12 years. The matches were processed for age, gender, income, region of residence, and past medical history. Mortality rates and causes of death were compared between groups. Regarding the mortality rates, we also performed subgroup analyses according to age. Adjusted hazard ratio (HR) of the TKA group for mortality rate was less than 1 with significance (adjusted HR = 0.61 (95% confidence interval = 0.54–0.70, p < 0.001)). The ratios were less than 1 for both age groups (<70 and ≥70 years), respectively; however, for patients under 70, they were insignificant. Among the 11 major causes of death, the circulatory disease showed the most significantly reduced mortality rate for the TKA group compared to the control group. The neoplasm was the only other cause with a significantly reduced mortality rate for the TKA group. The mortality rate in the TKA group was significantly lower than in the control group up to 12 years after the surgery in Korea. Among the major causes of death, circulatory disease and neoplasm showed a significant reduction in the mortality rate of the TKA group compared with the control group.

Background: With an increase in deep vein thrombosis (DVT) following total knee arthroplasty (TKA) in the Asian population, most surgeons today use a form of prophylactic anticoagulant agents in patients after TKA. Nevertheless, DVT occasionally develops even in these patients with prophylaxis. The purpose of this study was to identify the risk factors for DVT after TKA in cases of postoperative low-molecular-weight heparin (LMWH) use.Methods: We designed a retrospective study with 103 patients who underwent primary TKA. From the second postoperative day, 60 mg of LMWH was subcutaneously injected into the patients daily. On the seventh postoperative day, patients had computed tomography angiography to check whether they had DVT. Regarding risk factors, we investigated patients’ gender, age, surgical site (unilateral/bilateral), body mass index, method of anesthesia, preoperative hypertension, diabetes, hypercholesterolemia status, and prothrombin time/international normalized ratio from electronic medical records. We analyzed the statistical significance of these risk factors.Results: Statistically significant factors in the single-variable analysis were surgical site (unilateral/bilateral), body mass index, preoperative hypertension status, and anesthesia method. Multiple logistic regression analysis with these factors revealed that the surgical site (unilateral/bilateral,p = 0.024) and anesthesia method (p = 0.039) were significant factors for the occurrence of postoperative DVT after TKA.Conclusions: Patients undergoing simultaneous bilateral TKAs and patients undergoing TKA with general anesthesia need more attention regarding DVT even with chemoprophylaxis using LMWH after TKA.