Primary Total Knee Arthroplasty for Treating Osteoarthritic Knees with Neglected Patellar Dislocation.

Background and Objectives: Neglected patellar dislocation in the presence of end-stage osteoarthritis (OA) is a rare condition characterized by the patella remaining laterally dislocated without reduction. Due to the scarcity of reported cases, the optimal management approach is still uncertain. However, primary total knee arthroplasty (TKA) can serve as an effective treatment option. This study aimed to present the clinical and radiological outcomes achieved using our surgical technique. Materials and Methods: A retrospective review of 12 knees in 8 patients with neglected patellar dislocation and end-stage OA who underwent primary TKA was conducted. The surgical procedure involved conventional TKA techniques (e.g., medial parapatellar arthrotomy) and additional procedures specific to the individual pathologies of neglected patellar dislocation (e.g., lateral release, medial plication, and quadriceps lengthening). Clinical outcomes, including patient-reported outcome measures (PROMs) (Knee Society Scores and the Western Ontario and McMaster Universities Osteoarthritis Index) and knee range of motion (ROM), were assessed preoperatively and two years postoperatively. Radiological measures including mechanical femorotibial angle and patellar tilt angle were assessed preoperatively and until the last follow-up examinations. Any complications were also reviewed. Results: There were significant improvements in all PROMs, knee ROM, and radiological outcomes, including mechanical femorotibial angle and patellar tilt angle (all p < 0.05). At a mean follow-up of 68 months, no major complications requiring revision surgery, including patellar dislocation, were reported. Conclusions: Primary TKA is an effective procedure for correcting various pathologies associated with neglected patellar dislocation in end-stage OA without necessitating additional bony procedures. Satisfactory clinical and radiological outcomes can be expected using pathology-specific procedures.

Updated solution for diagnosis and management of calcinosis cutis: A retrospective review.

Calcinosis cutis is classified into 5 main types: dystrophic, metastatic, idiopathic, iatrogenic, and calciphylaxis. However, it is occasionally misdiagnosed as a malignancy and its management remains challenging. Therefore, in this study, we report our diagnostic and treatment experiences with patients with calcinosis cutis and suggest strategies for improving patient care. This retrospective study included 7 patients (4 men, 3 women; 44.4 ±â€…32.0 years old) who visited our hospital between March 2013 and December 2022 and were diagnosed with calcinosis cutis through histopathological procedures. The patients underwent complete excision of the mass without a safety margin. Frozen biopsy was not performed during surgery. No significant intraoperative or postoperative complications were noted after the application of various imaging techniques for diagnosis and follow-up. All patients showed complete recovery. Follow-up showed no recurrence or complications in the 6 patients who completed 1 year of follow-up. Radiological tests such as plain radiography, ultrasonography, computed tomography, and magnetic resonance imaging are important for accurate diagnosis and treatment of calcinosis cutis. This approach can ensure precise assessment of preoperative lesions, leading to safe and less invasive patient treatment, recurrence prevention, and complications of calcinosis cutis.

Comparative clinical feasibility of antireflux mucosectomy and antireflux mucosal ablation in the management of gastroesophageal reflux disease: Retrospective cohort study.

OBJECTIVES: No definitive treatment has been established for refractory gastroesophageal reflux disease (GERD). Antireflux mucosectomy (ARMS) and antireflux mucosal ablation (ARMA) using argon plasma coagulation are promising methods. However, no study has compared these two. This study compared the efficacy and safety of the two procedures. METHODS: This multicenter, retrospective, observational study included 274 patients; 96 and 178 patients underwent ARMA and ARMS, respectively. The primary outcome was subjective symptom improvement based on GERD questionnaire (GERDQ) scores. The secondary outcomes included changes in the presence of Barrett's esophagus, Los Angeles grade for reflux esophagitis, flap valve grade, and proton pump inhibitor withdrawal rates. RESULTS: The ARMS group had higher baseline GERDQ scores (10.0 vs. 8.0, P < 0.001) and a greater median postprocedure improvement than the ARMA group (4.0 vs. 2.0, P = 0.002), and even after propensity score matching adjustment, these findings remained. ARMS significantly improved reflux esophagitis compared with ARMA, with notable changes in Los Angeles grade (P < 0.001) and flap valve grade scores (P < 0.001). Improvement in Barrett's esophagus was comparable between the groups (P = 0.337), with resolution rates of 94.7% and 77.8% in the ARMS and ARMA groups, respectively. Compared with the ARMA group, the ARMS group experienced higher bleeding rates (P = 0.034), comparable stricture rates (P = 0.957), and more proton pump inhibitor withdrawals (P = 0.008). CONCLUSIONS: Both ARMS and ARMA showed improvements in GERDQ scores, endoscopic esophagitis, flap valve grade, and the presence of Barrett's esophagus after the procedures. However, ARMS demonstrated better outcomes than ARMA in terms of both subjective and objective indicators.

Anatomical Reference of the Femur after Distal Resection Is Reliable for Rotational Alignment in Total Knee Arthroplasty.

The rotational alignment of the femoral component in total knee arthroplasty (TKA) is considered an important factor, but it is still difficult to assess intraoperatively. This study was conducted to identify anatomical parameters for femoral rotational alignment. A total of 204 patients who underwent primary TKA between 2015 and 2019 were enrolled. The femoral lateral (FLAP) and femoral medial anteroposterior (FMAP) lengths were measured as the widest lengths in the anteroposterior (AP) axis after distal femoral resection. The difference between FLAP and FMAP was defined as dFAP. The concordance correlation coefficient (CCC) was assessed for agreement between the cTEA-PCA and the value of femoral rotation using the linear regression analysis equation. HKA, FLAP, FMAP, and dFAP were significantly associated with femoral rotational alignment. The prediction equation combining the novel intraoperative anatomical references showed improved association with rotational alignment. If dFAP was 6.0 mm, the femoral rotation angle was calculated as 4.9° using this univariate regression equation. The CCC was 0.483, indicating moderate agreement. The dFAP showed an association with distal femoral rotational alignment. A 6 mm dFAP could be a reference for around 5° of femoral rotation. The equation developed in this study may be a reliable tool for intraoperative distal femoral rotational alignment.

Novel hematopoietic progenitor kinase 1 inhibitor KHK-6 enhances T-cell activation.

Inhibiting the functional role of negative regulators in immune cells is an effective approach for developing immunotherapies. The serine/threonine kinase hematopoietic progenitor kinase 1 (HPK1) involved in the T-cell receptor signaling pathway attenuates T-cell activation by inducing the degradation of SLP-76 through its phosphorylation at Ser-376, reducing the immune response. Interestingly, several studies have shown that the genetic ablation or pharmacological inhibition of HPK1 kinase activity improves the immune response to cancers by enhancing T-cell activation and cytokine production; therefore, HPK1 could be a promising druggable target for T-cell-based cancer immunotherapy. To increase the immune response against cancer cells, we designed and synthesized KHK-6 and evaluated its cellular activity to inhibit HPK1 and enhance T-cell activation. KHK-6 inhibited HPK1 kinase activity with an IC50 value of 20 nM and CD3/CD28-induced phosphorylation of SLP-76 at Ser-376 Moreover, KHK-6 significantly enhanced CD3/CD28-induced production of cytokines; proportion of CD4+ and CD8+ T cells that expressed CD69, CD25, and HLA-DR markers; and T-cell-mediated killing activity of SKOV3 and A549 cells. In conclusion, KHK-6 is a novel ATP-competitive HPK1 inhibitor that blocks the phosphorylation of HPK1 downstream of SLP-76, enhancing the functional activation of T cells. In summary, our study showed the usefulness of KHK-6 in the drug discovery for the HPK1-inhibiting immunotherapy.

Comparative evaluation of endoscopic anti-reflux mucosectomy and stretta radiofrequency ablation in the management of gastroesophageal reflux disease: insights from a retrospective multicenter cohort study.

BACKGROUND: Treatment options for gastroesophageal reflux disease (GERD) that is unresponsive to proton pump inhibitors (PPIs) remain limited. Therefore, we compared the therapeutic effects of anti-reflux mucosectomy (ARMS) and Stretta radiofrequency (SRF) for intractable GERD in over 400 individuals who underwent either procedure. METHODS: We conducted a retrospective study between 2016 and 2023 to evaluate the effectiveness of SRF and ARMS treatments for refractory GERD. The primary measure of success was the change in the GERD questionnaire (GERDQ) score. The secondary outcomes were various GERD-related indicators, including endoscopic Los Angeles (LA) classification, Hill's type-based flap valve grade (FVG), EndoFLIP™ distensibility index (DI), rate of PPI discontinuation, resolution rate of Barrett's esophagus, and incidence of adverse events. RESULTS: The ARMS group included patients with high GERDQ scores, FVG, LA grade, and Barrett's esophagus. Both groups had similar rates of improvements in GERDQ score (P = 0.884) and PPI withdrawal (P = 0.866); however, the ARMS group had significantly more side effects and improvements in the median change in GERDQ score (P = 0.011), FVG (P < 0.001), LA grade (P < 0.001), EndoFLIP™ DI (P < 0.001), and resolution of Barrett's esophagus (P < 0.001). CONCLUSIONS: The ARMS group had a greater GERDQ score improvement than the SRF group but had symptom relief and PPI discontinuation rates similar to those of the SRF group. However, objective measures, including EndoFLIP™ DI and endoscopic evaluations, were better in the ARMS group than in the SRF group.

Antibacterial activities of phytochemicals against Porphyromonas gingivalis with and without experimental fluoride varnish for periodontal disease prevention.

We aimed to evaluate the antibacterial activity of phytochemicals with or without an experimental fluoride varnish against Porphyromonas gingivalis. Five phytochemicals, chrysophanol (CHR), emodin (EMO), anthrarufin (ANT), bavachalcone (BCC), and isobavachromene (IBC), were tested using agar diffusion, minimal inhibition concentration (MIC), and minimum bacterial concentration (MBC) assays. We also assessed the cell viability and cytotoxicity of phytochemicals. All phytochemicals showed clear inhibition zones in the agar diffusion test. The inhibition zones of all phytochemical-containing fluoride varnishes were similar to or larger than that of the positive control, excluding that of 1 mM EMO. With or without the fluoride varnish, BCC exhibited the lowest MIC and MBC levels. Cell viability was high in the presence of all phytochemicals except 200 µM EMO. In conclusion, BCC was most effective as a phytochemical alone, while all phytochemical-containing fluoride varnishes inhibited P. gingivalis growth without cytotoxicity.

Evaluation of Esthetic Results after Mass Removal with Elliptical Skin Excision Using Ultrasonography to Measure Skin Thickness.

Background: The growth of benign cutaneous masses causes the overlaying skin to expand and become thinner, especially at the central, most projected point. In this retrospective study, a surgical technique comprising an elliptical skin excision was employed to account for these skin changes. Methods: This retrospective study enrolled 980 patients with benign masses. Preoperatively, all patients underwent ultrasonography to evaluate the mass depth and thickness of the attached skin, and mass excision was performed using the elliptical skin-excision method. The operative time was recorded, and complications and esthetic outcomes were assessed using the Cutometer® and the modified Vancouver Scar Scale (mVSS) during 1- and 3-month follow-up visits. Results: The mean operative time (17.48 ± 3.46 min) was significantly shorter than that of conventional methods (p < 0.05). Cutometer parameters showed no significant differences from those of intact skin. The average mVSS scores were 5.21 ± 1.42 and 3.50 ± 1.79 at 1- and 3-month follow-ups, respectively. Conclusions: Mass excision with an elliptical skin attachment resulted in improved esthetic results and easy removal. The attached skin enabled convenient handling without damaging the capsule or other adjacent structures, leaving a thick dermis on both wound edges. Thus, this technique resulted in minimal scarring.

Pharmacological Inhibition of LRRK2 Exhibits Neuroprotective Activity in Mouse Photothrombotic Stroke Model.

Leucine-rich repeat kinase 2 (LRRK2) mutations are the most common cause of Parkinson's disease (PD). Interestingly, recent studies have reported an increased risk of stroke in patients with PD harboring LRRK2 mutations, but there is no evidence showing the functional involvement of LRRK2 in stroke. Here, we found that LRRK2 kinase activity was significantly induced in the Rose-Bengal (RB) photothrombosis-induced stroke mouse model. Interestingly, stroke infarct volumes were significantly reduced, and neurological deficits were diminished by pharmacological inhibition of LRRK2 kinase activity using MLi-2, a brain-penetrant LRRK2 kinase inhibitor. Immunohistochemical analysis showed p-LRRK2 level in stroke lesions, co-localizing with mitophagy-related proteins (PINK, Parkin, LC3B, cytochrome c), suggesting their involvement in stroke progression. Overlapping p-LRRK2 with cytochrome c/TUNEL/JC-1 (an indicator of mitochondrial membrane potential) puncta in RB photothrombosis indicated LRRK2-induced mitochondrial apoptosis, which was blocked by MLi-2. These results suggest that pharmacological inhibition of LRRK2 kinase activity could attenuate mitochondrial apoptosis, ultimately leading to neuroprotective potential in stroke progression. In conclusion, LRRK2 kinase activity might be neuro-pathogenic due to impaired mitophagy in stroke progression, and pharmacological inhibition of LRRK2 kinase activity could be beneficial in reducing the risk of stroke in patients with LRRK2 mutations.

Metal-Organic Frameworks Marry Sponge: New Opportunities for Advanced Water Treatment.

Metal-organic frameworks (MOFs) have garnered attention across various fields due to their noteworthy features like high specific surface area, substantial porosity, and adjustable performance. In the realm of water treatment, MOFs exhibit great potential for eliminating pollutants such as organics, heavy metals, and oils. Nonetheless, the inherent powder characteristics of MOFs pose challenges in terms of recycling, pipeline blockage, and even secondary pollution in practical applications. Addressing these issues, the incorporation of MOFs into sponges proves to be an effective solution. Strategies like one-pot synthesis, in situ growth, and impregnation are commonly employed for loading MOFs onto sponges. This review comprehensively explores the synthesis strategies of MOFs and sponges, along with their applications in water treatment, aiming to contribute to the ongoing advancement of MOF materials.

Da Vinci robot-assisted endoscopic full-thickness gastric resection with regional lymph node dissection using a 3D near-infrared video system: a single-center 5-year clinical outcome.

BACKGROUND: Endoscopic full-thickness gastric resection (EFTGR) with regional lymph node dissection (LND) has been used for early gastric cancer (EGC) exceeding the indications for endoscopic submucosal dissection (ESD). The extent of the dissected lymph nodes is crucial. A 3D near-infrared (NIR) video robot system significantly enhances visualization of the lymphatic system. However, this system has not been used in EFTGR with LND. Thus, this study assessed the benefits of the 3D NIR video robot system in a clinical setting. METHODS: Between February 2015 and September 2018, 24 patients with EGC exceeding the indications for ESD were treated with EFTGR and LND using a 3D NIR video system with the da Vinci surgical robot. Indocyanine green (ICG) was injected endoscopically around the tumor, and basin node (BN) dissection around the nodes was examined using the 3D NIR video system of the da Vinci Si surgical robot. Subsequently, robot-assisted EFTGR was performed. The primary outcome was the 5-year survival rate. RESULT: During a 5-year follow-up of all 24 patients, an 80-year-old patient with an ulcer and T2 invasion was lost to follow-up. Among the remaining 23 patients, no mortality or recurrence was observed. CONCLUSION: No metastasis or mortality occurred using the da Vinci robot-assisted EFTGR with LLND and a 3D NIR video system for patients who required radical gastrectomy for EGC in over 5 years. Hence, this may be a safe and effective method for radical gastrectomy; further studies are required confirming its effectiveness.

Endoscopic resection and laparoscopic lymph node dissection for early gastric cancer beyond conventional endoscopic treatment indications: a 10-year outcome study.

BACKGROUND: Endoscopic full-thickness gastric resection (EFTGR) with laparoscopic regional lymph node dissection (LLND) and endoscopic submucosal dissection (ESD) with LLND have been investigated as treatment options for early gastric cancer beyond the absolute indications for ESD. However, comparative studies on the long-term outcomes of these procedures are lacking. This study aimed to analyze and compare the 10-year outcomes of both procedures in a real clinical setting. METHODS: Between January 2009 and December 2013, 28 and 37 patients diagnosed with EGC beyond the absolute indications for ESD were treated with EFTGR with LLND and ESD with LLND, respectively. In both procedures, the dye was injected into the tumor. However, after injection and LLND, EFTGR was performed immediately in the EFTGR with LLND group, whereas LLND was followed by ESD in the ESD with LLND group. The primary endpoint was the 10-year survival rate. RESULTS: The EFTGR with LLND group had one case of local recurrence (3.6%) and mortality (3.6%) each, while the ESD with LLND group had none (0.0% for both); however, the differences were not statistically significant (P = 0.247 for each). Furthermore, there was no significant difference in complications such as ischemia and anastomosis leakage between the groups (P = 0.247). CONCLUSIONS: When the procedures were properly applied, EFTGR with LLND and ESD with LLND did not increase the 10-year mortality in patients with EGC beyond the absolute ESD indications compared with conventional radical gastrectomy.

Transumbilical Silicone Breast Augmentation: A 13-Year Experience and 5-Year Analysis.

BACKGROUND: Transumbilical breast augmentation (TUBA) with saline implants has been considered a safe and efficient technique for decades. However, because silicone implants are more popular than saline ones, TUBA with saline implants is not widely performed. In 2014, we published a report on transumbilical breast augmentation using silicone cohesive gel implants. As we have performed transumbilical silicone breast augmentation (TUSBA) for 13 years with slight modifications, this study aimed to describe this novel technique and present accompanying patient outcomes over 5 years. METHODS: We enrolled patients desiring breast augmentation at a single center. The preoperative design was initially determined with the patients in standing positions before they underwent surgery under general anesthesia in a supine position. RESULTS: Between January 2018 and December 2022, 69 women and one man underwent TUSBA at a single center. All patients underwent cohesive gel silicone implantation in the subpectoral pocket. The implant size varied from 225 to 300 mL (average 272 mL) because two patients underwent surgery with implants of different sizes due to breast asymmetry. All patients were satisfied with the surgery outcome except one who was dissatisfied because of abdominal bulging. CONCLUSIONS: TUSBA offers advantages such as minimal scarring and unrestricted arm movement; thus, it can be an alternative option for patients seeking breast augmentation. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors https://www.springer.com/00266 .

Comparative Analysis of Temperature-Responsive Hydrogel (PF 72) for Postoperative Pain After Bimaxillary Surgery: A Retro-spective Study.

Bimaxillary surgery is a painful invasive procedure in plastic surgery. Pain control is typically achieved using intravenous analgesics. We aimed to investigate the efficacy of a novel temperature-responsive hydrogel, PF72, mixed with ropivacaine, as a local pain management solution when applied directly to the surgical site following orthognathic surgery. The study was conducted from October 2022 to July 2023 and included a cohort of 40 candidates for orthognathic surgery, encompassing LeFort I maxillary ostectomy and sagittal split ramus osteotomy. The participants were divided into an Injection group (n = 20), where PF72 was administered at the surgical site before the orthognathic surgery, and a Control group (n = 20), which relied solely on intravenous analgesics. Pain was evaluated at 3, 6, 24, 48, and 72 h after surgery using a numerical rating scale (NRS). The mean NRS scores at 24 h were 6.35 and 4 for the Control and Injection groups, respectively. The mean NRS scores at 72 h were 3.4 and 2.55 for the Control and Injection groups, respectively. Patients who received PF72 experienced less pain than those who received intravenous analgesics. These findings underscore the potential of PF72 as an effective alternative for enhancing pain management in patients undergoing orthognathic surgery.Level of Evidence III Therapeutic study. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Efficacy and safety of MC-003 solution for endoscopic mucosal or submucosal resection: a prospective, multicenter, randomized, triple-blinded, parallel-group, phase III study.

BACKGROUND AND AIMS: The safety and efficacy of solutions for submucosal injection are critical for endoscopic resection of gastric adenomas or early gastric cancers. Although several injectable solutions have been introduced for endoscopic resection, they have some limitations. We aimed to compare the efficacy of the new sodium alginate-based solution MC-003 with that of normal saline (NS; 0.9% sodium chloride). METHODS: In this randomized, triple-blind study, 70 patients were initially enrolled for EMR or endoscopic submucosal dissection (ESD). The main outcomes included the need for additional injections, completion of en bloc resection, and occurrence of adverse events. RESULTS: Each group ultimately included 34 patients. Complete en bloc resections were achieved in all patients (P = 1.000). The MC-003 group had more peri-neoplasm tissue fibrosis (P = .056) and needed fewer additional injections for lesions >15 mm (P = .037), located in the distal portion of the stomach (P = .007), and during ESD procedures (P = .001). The adverse event rate was comparable in both groups. CONCLUSIONS: MC-003 outperformed NS in reducing the need for additional injections during en bloc resection, particularly in larger lesions located in the distal portion of the stomach (where most lesions were found) during ESD procedures, without increasing the incidence of serious adverse events. MC-003 is a promising submucosal injectable solution in real-world clinical settings.

Increased Blood Pressure Variability Over a 16-Year Period Is Associated With Left Ventricular Diastolic Dysfunction in a Population-Based Cohort.

BACKGROUND: Left ventricular diastolic dysfunction (LVDD) is often associated with elevated blood pressure (BP). It is prevalent among hypertensive patients. Additionally, increased BP variability has been linked to LVDD. However, the precise connection between LVDD and BP variability within the general population remains unclear. Thus, this study aimed to evaluate this association in a general population. METHODS: A total of 2,578 participants(1,311 females) with a mean age of 47.8 ±â€…6.7 years who had echocardiographic data from the Korean Genome and Epidemiology study with 16 years of follow-up were analyzed. LVDD was identified through the last echocardiography during the follow-up period. BP variability was assessed using mean, standard deviation (SD), and coefficient of variance (CV). RESULTS: LVDD was detected in 249 individuals. The cohort was divided into an LVDD group and a normal LV diastolic function group. The LVDD group had a higher percentage of females, more advanced age, higher body mass index (BMI), higher BP and BUN levels, lower heart rate, lower hemoglobin, and lower serum creatinine than the normal LV diastolic function group. Remarkably, LVDD was associated with higher BP variability. In the multivariate analysis, LVDD was associated with increased age, female sex, increased BMI, hypertension, and increased BUN. Elevated mean systolic and diastolic BPs, SD of systolic BP, mean pulse pressure (PP), SD of PP, and CV of PP were significantly linked to LVDD even after adjusting for other significant variables in the multivariate analysis. CONCLUSIONS: LVDD was identified in 249 (9.7%) participants. Increased long-term BP variability was significantly associated with LVDD in this population-based cohort.

Accuracy of Advanced Active Robot for Total Knee Arthroplasty: A Cadaveric Study.

Although the accuracy of other types of robotic systems for total knee arthroplasty (TKA) has been assessed in cadaveric studies, no investigations have been performed to evaluate this newly advanced active robotic system. Therefore, the authors aimed to analyze the accuracy of bone resection in terms of thickness and alignment in a cadaveric study. Three cadaveric specimens (six knees) and an active robotic system (CUVIS Joint, CUREXO) were used in the study. Three surgeons with different experiences in robotic TKAs performed this cadaveric study using the same robotic protocol with two different implant designs. The thickness and angle of bone resection planes obtained from the optical tracking system and the difference between resection planes and the planning data were assessed to determine accuracy. With respect to the overall resection accuracy compared to the plan, the cutting depth accuracy was within 1.0 mm mean of root mean square (RMS), and the resection angle accuracy in terms of sagittal, coronal, and axial planes was within 1.0 degree mean RMS. In contrast, no significant differences were observed between the planned and measured values in terms of the resection angles and cutting thickness. The hip-knee-ankle angle at postoperative evaluation was 0.7 degrees ± 0.7 degrees (RMS 1.0 degrees). This in vivo study suggests that the use of this newly advanced active robotic system for TKA demonstrates a high degree of accuracy in terms of resection thickness and alignment. This finding supports the clinical application of this advanced robotic system. LEVEL OF EVIDENCE: Cadaveric study, Level V.

"Boot Sign" of Anterior Femoral Condylar Resectional Shape during Total Knee Arthroplasty Is More Frequent in Asian Patients.

PURPOSE: There is lack of intraoperative consensus on the distal femur anterior resected surface shape that allows reliable rotational alignment assessment during total knee arthroplasty (TKA). We aimed to evaluate the ratio and prevalence of anterior femoral resection surface intraoperatively. MATERIALS AND METHODS: The study included 234 osteoarthritis patients with varus knees and not valgus knees or deformities. After conventional medial parapatellar approach, measured resection technique based on the mechanical axis of the femur and preoperative TEA-PCA angle on CT with anterior reference was used among all the patients. The anteroposterior (AP) lengths after distal femoral resection were measured as the femoral lateral AP (FLAP) and femoral medial AP (FMAP) lengths. Based on the medial (MD) and lateral condyle (LD) vertical distance ratios of the femur anterior resected surface, the groups were classified into "boot sign", "grand-piano", and "butterfly sign" groups. For comparison of the mean values, the data were assessed for normality with the Shapiro-Wilk test. One-way ANOVA with post hoc analysis using Tukey's honestly significant difference (HSD) test was used to compare the mean values among the groups. The correlations between the MD/LD and variables were analyzed using the Pearson correlation coefficient. Linear regression analyses were used to find the associated factors to the anterior femoral resection surface shape. RESULTS: Mean intraoperative femoral rotation and distal femoral cutting angles were 4.9° ± 1.2 and valgus 5.0° ± 0.7, respectively. Mean FLAP was 52.9 ± 4.2 mm. Mean MD/LD (0.61 ± 0.13) was lower than that of typical "grand-piano sign". The morphological shape incidence of the "boot sign" was 62.4%. In the "boot sign" group, the FLAP was found to be smaller than that in the other groups (52.4 ± 4.2 vs. 53.7 ± 4.2 vs. 54.9 ± 2.7; p = 0.02), while the intraoperative femoral rotation angle was found to be larger than in the other groups (5.0 ± 1.2 vs. 4.6 ± 1.1 vs. 4.7 ± 1.2; p = 0.039). The MD/LD-associated factors were FLAP, intraoperative femoral rotation, and distal femoral cutting angles (R2 = 0.268). CONCLUSION: The femur anterior resection surface shape in TKA was found in the "boot sign" rather than the "grand-piano sign" in Korean ethnics owing to an asymmetric morphology of femoral condyles. Ethnic differences, including distal femoral morphology, should be considered for assessment of the femoral rotation angle using the femur anterior resection surface shape.