Comparison between accuracy of augmented reality computed tomography-based and portable augmented reality-based navigation systems for cup insertion in total hip arthroplasty.

Augmented reality (AR) has been used for navigation during total hip arthroplasty (THA). AR computed tomography (CT)-based navigation systems and AR-based portable navigation systems that use smartphones can also be used. This study compared the accuracy of cup insertion during THA using AR-CT-based and portable AR-based navigation systems. Patients with symptomatic hip disease who underwent primary THA in the supine position using both AR CT-based and portable AR-based navigation systems simultaneously between October 2021 and July 2023 were included. The primary outcome of this study was the absolute difference between cup angles in the intraoperative navigation record and those measured on postoperative CT. The secondary outcome was to determine the factors affecting the absolute value of the navigation error in radiographic inclination (RI) and radiographic anteversion (RA) of the cup, including sex, age, body mass index, left or right side, approach, and preoperative pelvic tilt. This study included 94 consecutive patients. There were 11 men and 83 women, with a mean age of 68 years. The mean absolute errors of RI were 2.7° ± 2.0° in the AR CT-based and 3.3° ± 2.4° in the portable AR-based navigation system. The mean absolute errors of RA were 2.5° ± 2.1° in the AR CT-based navigation system and 2.3° ± 2.2° in the portable AR-based navigation system. No significant differences were observed in RI or RA of the cup between the two navigation systems (RI: p = 0.706; RA: p = 0.329). No significant factors affected the absolute value of the navigation errors in RI and RA. In conclusion, there were no differences in the accuracy of cup insertion between the AR CT-based and portable AR-based navigation systems.

Pedicled flap transfer after chest wall malignant tumor resection and potential risk of postoperative respiratory problems for patients with low FEV1.0.

Introduction: Musculoskeletal transfer for chest wall tissue defects is a crucial method, and pedicled flaps around the chest wall are preferred in terms of location and simplicity of transfer. These require special care because of complications such as partial necrosis, fistula, wound dehiscence, infection, hematoma and restricted function of the arm or shoulder. However, studies of respiratory function are rare. In the present study, we investigated the complications including respiratory problems after wide resection for malignant chest wall tumors with musculoskeletal pedicle transfer. Methods: A total of 13 patients (15 operations) who underwent wide resection of primary, recurrent, or metastatic malignant chest wall tumors and musculoskeletal pedicle transfer for coverage of tissue defects were enrolled in the present study. A retrospective review of all patients was performed using data collected from hospital records and follow-up information. The complications of musculoskeletal transfer after chest wall wide resection, including respiratory problems, are evaluated. Results: Rib or sternal resection was performed in 12 operations, and only soft tissue resection was performed in 3 operations. Latissimus dorsi (LD) pedicle transfer was performed in 13 operations, and pectoralis major (PM) pedicle transfer was performed in 2 operations; basically, wounds were closed primarily. Surgical complications were observed following 5 of the 15 operations (33.3%). Respiratory complications were seen in 7 of the 15 operations (46.7%). Patients with respiratory complications showed significantly lower preoperative FEV1.0% values than those without respiratory complications (p = 0.0196). Skin resection area tended to be higher in the complication group than in the no complication group (p = 0.104). Discussion: Pedicled myocutaneous flap transfers such as LD, PM, and rectus abdominus can be used following multiple resections. After harvesting LD or PM, the wound can be closed primarily for an 8-10-cm skin defect in patients with normal respiratory function. However, for patients with low FEV1.0%, after primary closure of LD or PM transfer for wide soft tissue defects, attention should be paid to postoperative respiratory complications.

Accuracy of cup placement and pelvic motion in total hip arthroplasty in the lateral decubitus position using a new computed tomography-based navigation system with augmented reality technology.

INTRODUCTION: This study aimed to investigate the accuracy of cup position and assess the changes in pelvic tilt during primary total hip arthroplasty (THA) in the lateral decubitus position using a new computed tomography (CT)-based navigation system with augmented reality (AR) technology. MATERIALS AND METHODS: There were 37 cementless THAs performed using a CT-based navigation system with AR technology in the lateral decubitus position and 63 cementless THAs performed using manual implant techniques in the lateral decubitus position in this retrospective study. Postoperative cup radiographic inclination and anteversion were measured using postoperative CT, and the proportion of hips within Lewinnek's safe zone was analyzed and compared between the two groups. The mean absolute values of navigation error were assessed. Intraoperative pelvic tilt angles were also recorded using navigation system. RESULTS: The percentage of cups inside Lewinnek's safe zone was 100% in the navigation group and 35% in the control group (p < 0.001). The mean absolute values of navigation error in inclination and anteversion were 2.9° ± 2.1° and 3.3° ± 2.4°, respectively. The mean abduction angle of the pelvis was 5.1° ± 4.8° after placing the patients in the lateral decubitus position and 4.1° ± 6.0° after cup placement. The mean posterior tilt angle was 6.8° ± 5.1° after placing the patients in the lateral decubitus position and 9.3° ± 5.9° after cup placement. The mean internal rotation angle was 14.8° ± 7.4° after cup placement. There were no correlations between the navigation error in inclination or anteversion and the absolute values of changes of the pelvic tilt angle at any phase. CONCLUSIONS: Although progressive pelvic motion occurred in THA in the lateral decubitus position, especially during cup placement, the CT-based navigation system with AR technology improved cup placement accuracy.

Long-Term Outcome of Metal-on-Metal Total Hip Arthroplasty with Modular Neck Stem.

Background: This study aimed to report the long-term outcomes of total hip arthroplasty (THA) using a Conserve Plus (Wright Medical, Japan) metal-on-metal (MoM) acetabular prosthesis with a modular neck stem. Methods: This study enrolled 50 patients (10 men and 40 women; mean age, 65.8 (39-87) years) who underwent primary THA using a Conserve Plus MoM acetabular prosthesis with a modular neck stem. The preoperative diagnosis in most patients was osteoarthritis. Clinical function of hip joint outcomes was investigated using the Japanese Orthopedic Association (JOA) hip score preoperatively and at the final follow-up. The perfect JOA hip score was 100, while the worst score was 0. Radiological analyses were evaluated during the final follow-up visit. Magnetic resonance imaging (MRI) images were evaluated to screen for pseudotumors in 43 hips postoperatively. Results: Six patients did not visit before their 10-year follow-up for unknown reasons. Therefore, 44 patients were evaluated at a mean of 11-years of follow-up (10-12 years). The mean (±SD) preoperative JOA hip score of 44.2 (±15.5) improved significantly to 85.1 (±12.9) postoperatively at the final follow-up (n = 36 hips, excluding eight revision cases). One patient underwent femoral fixation for a periprosthetic fracture due to trauma that occurred 4 years postoperatively. Spot welds were identified in 93.2% (41/44 hips) of cases. Severe (third- and fourth-degree) stress shielding was identified in 40.9% (18/44 hips) of cases. Twenty-two patients (51.2%) had pseudotumors attributable to MoM articulation based on MRI results, 2 to 10 years after arthroplasty. Three hips showed cup osteolysis (7%) and three showed trochanteric region osteolysis (7%). There were seven cup and/or three stem revisions for aseptic loosening and/or osteolysis at 4 months (with trauma) and 3.3 to 11 years (with pseudotumor) postoperatively. The Kaplan-Meier survivorship for the THA construct in this group was constant at 93.0% and 75.9% at 10 and 12 years after arthroplasty, respectively. The rates of survivorship of revision and loss of follow-up at 10 and 12 years were 83.9% and 66.8%, respectively. Conclusions: In summary, we reported on the long-term treatment results of MoM THA, precautions based on our cohort's findings, and the measures taken to address these issues, such as revision replacement and its outcomes. Clinical scores revealed good outcomes during the mean 11-year follow-up period. However, the prevalence of pseudotumors (PTs) was 51.2%. Some cases required revisions even after the 10 years following surgery. This is because in MoM THA, PT occurrence increases over time, and as a result, there were cases in which revised THA was required even after 10 years.

Prevalence and risk factors of ankle osteoarthritis in a population-based study.

BACKGROUND: This study aimed to investigate the prevalence of radiographic ankle osteoarthritis (AOA) in Japan and identify its risk factors. METHODS: The analysis included data from the population-based cohort study, radiographs of the knees and ankles, ultrasonography of the ankle to examine chronic ankle instability (CAI), and questionnaires on ankle pain, job history, height, and body weight. A total of 597 individuals aged > 50 years were included in the study. The risk factors for AOA were calculated using multivariate logistic regression analysis. RESULTS: The study revealed a 13.9% prevalence of radiographic AOA among the participants, with 1.2% reporting painful AOA. Female sex, aging, history of ankle fractures, and CAI were identified as the risk factors associated with AOA. CONCLUSIONS: This cross-sectional study highlights the significant prevalence of radiographic AOA in a rural Japanese population, emphasizing the importance of considering ankle fractures and CAI as potential risk factors for AOA development. LEVELS OF EVIDENCE: Level II, prospective cohort study.

The Combined Use of Inflammation Markers, Modified Glasgow Prognostic Score, and Sarculator Nomogram in Extremity Soft Tissue Sarcoma: A Multicenter Observational Study.

BACKGROUND: Sarculator is a validated nomogram designed to predict overall survival (OS) in extremity soft tissue sarcoma (STS). Inflammation plays a critical role in cancer development and progression. There were no reports which investigated the relationship between Sarculator and inflammation. METHODS: A total of 217 patients with extremity STS were included. The Sarculator-predicted 10-year probability of OS (pr-OS) was stratified into two subgroups: lower risk (10-year pr-OS ≥ 60%) and higher risk (10-year pr-OS < 60%). The modified Glasgow prognostic score (mGPS) varied from 0 to 2. RESULTS: Out of the 217 patients, 67 were classified as higher risk, while 150 were lower risk. A total of 181 patients had an mGPS of 0, and 36 had a score of 1 or 2. The 5-year OS was 83.3%. When patients were divided into two groups according to the 10-year pr-OS, those with a higher risk had poorer OS than those with a lower risk. Among the patients with a higher risk, those with an mGPS of 1 or 2 had poorer OS compared to those with a score of 0. CONCLUSIONS: The mGPS could potentially play an important role in identifying patients who are at high risk of death and metastasis in the higher-risk group on the Sarculator.

Two- and three-dimensional evaluations following handheld robot-assisted total knee arthroplasty.

Robot-assisted total knee arthroplasty (TKA) has proven to be successful in improving the accuracy of component positioning and reducing radiographic outliers. This study aimed to evaluate and compare the alignment of the components using two- and three-dimensional (2D and 3D) measurements following handheld imageless robot-assisted TKA. Seventy consecutive patients underwent primary TKA at our institution using a handheld robot-assisted system. Full-length standing anteroposterior and lateral radiographs were obtained 2 weeks after surgery for assessment of 2D component alignments. Pre- and postoperative computed tomography (CT) images were obtained to assess 3D component alignment. The reference points defined on preoperative CT images were transferred to the postoperative CT images. The absolute errors in the 2D and 3D component alignments from the planned, validated cutting, and validated implantation angles were calculated. Outliers of > ± 3° of femoral and tibial component alignments in the coronal and sagittal planes were also investigated. All absolute errors in the 2D and 3D component alignments were < 1°, except for the planned and validated cutting angles of the femoral sagittal alignment. No outliers were observed in the femoral or tibial component in the coronal plane. Significant differences between the 2D and 3D measurements were observed for the mean absolute value from the planned and validated cutting angles in the femoral sagittal plane and from the validated implantation angle in the tibial coronal plane. The handheld robot-assisted system demonstrated a high accuracy for component alignment using 2D and 3D evaluations.

Comparison of accuracy and early outcomes in robotic total knee arthroplasty using NAVIO and ROSA.

This study aimed to compare the cutting and component placement accuracies and early outcomes after total knee arthroplasty (TKA) between an image-free handheld robotic system (NAVIO) and a radiography-based robotic system (ROSA). This retrospective study included 88 patients (88 knees) who underwent TKA using the NAVIO (40 patients) or ROSA (48 patients) robotic systems. The accuracies of the robotic systems were compared. Clinical scores were evaluated using the Knee Society Score 2011 (KSS 2011) and the forgotten joint score (FJS)-12 at 1 year postoperatively. The femoral sagittal cutting error was smaller in the NAVIO group than in the ROSA group. The other cutting errors were not statistically different in both groups. Implantation errors did not differ between the groups. Regarding the clinical outcomes of the KSS 2011 subscales, the symptoms score was higher in knees operated using ROSA than in those using NAVIO. The other KSS 2011 subscales and the FJS-12 showed no differences between the two groups. In conclusion, the femoral sagittal cutting error was smaller in the NAVIO group than in the ROSA group, and the KSS 2011 symptom score subsection at one year was higher in the knees operated using ROSA than in those using NAVIO.

Progression of vertebral deformity of prevalent vertebral fractures in the elderly: a population-based study.

BACKGROUND: Little is known about the progression pattern of vertebral deformities in elderly patients with prevalent vertebral fractures. This population-based cohort study investigated the incidence, progression pattern, and risk factors of vertebral deformity in prevalent vertebral fractures over a finite period of four years in a population-based cohort study. METHODS: A total of 224 inhabitants of a typical mountain village underwent medical examinations every second year from 1997 to 2009, and each participant was followed up for four years. The extent (mild, moderate, severe) and type (wedge, biconcave, crush) of prevalent vertebral fractures on spinal radiographs were evaluated using the Genant semi-quantitative method. Of these participants, 116 with prevalent vertebral fractures at baseline (32 men and 84 women; mean age: 70.0 years) were included in this study. The progression patterns of the 187 vertebral fractures with mild and moderate deformities (except severe deformity) were evaluated. Logistic regression analysis was used to identify the risk factors associated with deformity progression. RESULTS: The progression of vertebral deformities was identified in 13.4% (25 vertebral fractures) of the total 187 prevalent (mild and moderate) vertebral fracture deformities over four years. Among the three deformity types, the prevalence of deformity progression was significantly lower in wedge-type vertebral fractures (P < 0.05). Age and number of prevalent vertebral fractures per participant were independent risk factors associated with the progression of prevalent vertebral deformities. CONCLUSION: This study clarified the natural history of the progression pattern of vertebral deformities in radiographic prevalent vertebral fractures in elderly individuals. Multiple vertebral fractures in the elderly present a risk for the progression of vertebral deformities.

Screening for Synergistic Reagents With Pazopanib Against Osteosarcoma Using a Compound Library.

BACKGROUND/AIM: Osteosarcoma (OS) is the most common malignant bone tumor. As the same agents have been in use since the mid-1970s, new therapeutic approaches are needed to improve prognosis. Pazopanib (PZP) has already demonstrated marked antitumor activity clinically and can be effective in patients with metastatic OS. We investigated the combination treatment of candidate agents with PZP and examined effects on tumor growth using an in vivo model. MATERIALS AND METHODS: A library of 324 compounds was used. MG63 OS cells were treated with PZP and each compound. Cell viability was measured. The antiproliferative effects of compound combination on four OS cell lines was tested. Cell signaling was evaluated by western blot analysis. In vivo antitumor testing was performed using 143B-bearing mice. RESULTS: The screening process identified crizotinib (CRZ) as the most effective drug for combination with PZP. The combination of PZP and CRZ demonstrated effects compared to control or single therapy. Cell signal investigation showed that dual therapy down-regulated c-MYC, p-AKT, p-STAT3, p-cyclin D1 and survivin and up-regulated cleaved caspase-3 and cleaved PARP compared to control or single therapy. In vivo analysis showed dual therapy achieved synergic effects for tumor growth compared to control or single-treatment groups. No significant difference in the change in body weight was observed among groups. CONCLUSION: Combined use of PZP and CRZ offers synergic anti-tumor effects against OS, inducing apoptosis in vitro and in vivo by down-regulating AKT and STAT3. Our data suggest that these agents can be used for patients clinically.

The Effect of Photodynamic Therapy Using 5-Aminolevulinic Acid in Bone and Soft Tissue Sarcoma Cells.

BACKGROUND/AIM: 5-Aminolevulinic acid (5-ALA) is a natural amino acid and a precursor of protoporphyrin IX (PpIX). Following light irradiation, the PpIX generates reactive oxygen species (ROS) in the presence of oxygen. Increased ROS levels can cause apoptotic cell death and necrosis of targeted cancer cells. This study examined whether photodynamic therapy using 5ALA (5-ALA PDT) could be used as a potential adjuvant therapy for bone and soft tissue sarcomas. MATERIALS AND METHODS: The human osteosarcoma (143B), mouse osteosarcoma (LM8), human fibrosarcoma cell (HT1080) cell lines were used. In vitro, cultured cells were exposed to 5-ALA at various concentrations followed by strobe scope light irradiation for 10 min as 5-ALA PDT. Cell viability was then measured. In vivo, each tumor cell line was inoculated subcutaneously into the backs of mice. In the 5-ALA PDT group, 5-ALA (250 mg/kg) was administered intraperitoneally followed by light irradiation. Change in tumor volume by 5-ALA PDT were primarily evaluated. RESULTS: In vitro, treatment of sarcoma cells with 100 and 200 µg/ml 5-ALA PDT significantly inhibited cell proliferation at 24 and 48 h compared with the group treated with 0 and 10 µg/ml 5-ALA PDT. In vivo, in all cell lines, a significant inhibition of the tumor volume was observed in the 5-ALA-PDT group as compared to that in control, strobe scope light, and 5-ALA groups. CONCLUSION: 5-ALA PDT effectively inhibited proliferation of bone and soft tissue sarcoma cell lines. Further in vivo research using other subtypes of bone and soft tissue sarcoma is warranted to confirm the applicability in the clinical setting.

C­reactive protein and related predictors in soft tissue sarcoma (Review).

C-reactive protein (CRP) is a useful predictor of poor survival in patients with several types of cancer because inflammation is strongly associated with cancer progression. The production of CRP in hepatocytes appears to be primarily induced at the transcriptional level following the elevation of circulating interleukin-6 (IL-6), which is produced by various cell types, including cancer cells and cancer-associated fibroblasts. Serum CRP levels are associated with serum IL-6 levels in patients with soft tissue sarcoma (STS). Additionally, patients with elevated CRP levels had worse oncological outcomes than those with normal CRP levels. It has been attempted to combine CRP levels with other inflammatory or immune markers, and the utility of this has been demonstrated. Therefore, a novel treatment strategy should be developed for patients with STS with elevated CRP levels. The present review aimed to clarify the role of CRP levels and related tools in predicting clinical outcomes in patients with STS.

Minimum 7-year results of cementless total hip arthroplasty with vitamin E-diffused and 2-methacryloyloxyethyl phosphorylcholine-grafted highly cross-linked polyethylene.

The purpose of this study was to evaluate the mid-term clinical results and polyethylene wear of vitamin E-diffused highly cross-linked polyethylene (HXLPE) and 2-methacryloyloxyethyl phosphorylcholine (MPC)-grafted HXLPE in cementless total hip arthroplasty (THA). Thirty-four THAs with vitamin E-diffused HXLPE (VEPE) and 32-mm cobalt-chromium head, and 116 THAs with MPC-grafted HXLPE and 32-mm alumina head were evaluated. The Merle d'Aubigné and Postel scores were administered. Kaplan-Meier survivorship was analyzed. Annual radiographs were analyzed using computerized method and linear steady-state wear rate was measured. The mean duration of follow-up was 9 years (range, 7-11 years) in VEPE group and 8 years (range, 7-10 years) in MPC group. The mean Merle d'Aubigné and Postel scores improved postoperatively in both groups. Kaplan-Meier survivorship with endpoint of revision was 100% (95% confidence interval, 100%-100%) in VEPE group and 98.3% (95% confidence interval, 93.4%-99.6%) in MPC group at 10 years (P = .44). The mean steady-state wear rate was 0.007 mm/year in VEPE group and 0.006 mm/year in MPC group (P = .60). The clinical results of both groups were good and wear rates of both liners were very low.

Two- and three-dimensional measurements of leg length change using an accelerometer-based portable navigation system in total hip arthroplasty.

BACKGROUND: The aim of this study was examining the accuracy of accelerometer-based portable navigation systems (HipAlign) when measuring leg length changes using two-dimensional (2D) and three-dimensional (3D) methods. METHODS: Inclusion criteria were patients ≥ 20 years old with symptomatic hip disease who underwent primary total hip arthroplasty (THA) in the supine position using HipAlign between June 2019 and April 2020. The exclusion criteria were patients who underwent THA via a posterior approach. We examined correlations between the leg length change measurement with HipAlign and either 2D or 3D measurement. We performed a multivariate analysis to determine which factors may have influenced the absolute error results. RESULTS: This study included 34 patients. The absolute error in leg length change between the HipAlign and 3D measurement (4.0 mm) was greater than the HipAlign and 2D measurement (1.7 mm). There were positive correlations between leg length change with HipAlign and 2D and 3D measurements. Male patients had larger errors with 2D measurement. No significant factors were identified for 3D measurement. CONCLUSION: HipAlign provided acceptable measurement accuracy for leg length changes.

Expression of Glial-Cell-Line-Derived Neurotrophic Factor Family Ligands in Human Intervertebral Discs.

Glial-cell-line-derived neurotrophic factor (GDNF) family ligands (GFLs) contribute to the sensitization of primary afferents and are involved in the pathogenesis of inflammatory pain. The purpose of this preliminary study was to examine the expression of other GFLs (neurturin (NRTN), artemin (ARTN), persephin (PSPN)) and receptors in human IVD cells and tissues exhibiting early and advanced stages of degeneration. Human IVD cells were cultured as a monolayer after isolation from the nucleus pulposus (NP) and anulus fibrosus (AF) tissues. The mRNA expression of NRTN, ARTN, PSPN, and their receptors (GFRA2-GFRA4) was quantified using real-time PCR. Protein expression was evaluated using immunohistochemistry and Western blotting. The expression of NRTN, ARTN, PSPN, and their co-receptors (GFRA2-GFRA4) was identified in human IVD cells at both mRNA and protein levels. A trend was noted wherein the mRNA expression of ARTN, PSPN, and GFRA2 was upregulated by IL-1ß treatment in a dose-dependent manner. The percentages of immunopositive cells in the advanced degenerate stage of ARTN, PSPN, and GFRA2 were significantly higher than those in the early degenerate stage. Their expression was enhanced in advanced tissue degeneration, which suggests that GFLs (ARTN and PSPN) may be involved in the pathogenesis of discogenic pain.

Regenerative effects of platelet-rich plasma releasate injection in rabbit discs degenerated by intradiscal injection of condoliase.

BACKGROUND: Intradiscal condoliase injection is an alternative therapeutic option for lumbar disc herniation (LDH). However, it is often associated with disc degeneration. Several in vivo studies have demonstrated the regenerative potential of platelet-rich plasma (PRP) in disc degeneration. Thus, we hypothesized that the intradiscal injection of PRP releasate (PRPr), a soluble releasate isolated from PRP, has the potential to regenerate degenerated intervertebral discs (IVDs) induced by condoliase. This study examined the regenerative effects of PRPr on rabbit IVDs degenerated following condoliase injection. METHODS: Eleven New Zealand white rabbits were used in this study. Condoliase (12.5 mU/10 µl) was injected into two non-contiguous discs (L2-L3 and L4-L5), and L3-L4 disc was left intact as a non-injection control. Saline (20 µl) or PRPr (20 µl) was randomly injected into L2-L3 and L4-L5 discs 4 weeks after the condoliase injection. Disc height (DH) was radiographically monitored biweekly from the day of condoliase injection to 16 weeks post-injection. Changes in DH were expressed as percentage DH (%DH) normalized to the baseline DH. Sixteen weeks after condoliase injection, all rabbits were euthanized, and subjected to MRI and histological analyses. RESULTS: Intradiscal injection of condoliase induced a significant decrease in %DH (L2-L3 and L4-L5) to 52.0% at week 4. However, the %DH began to return to normal after saline injection and reached 76.3% at week 16. In the PRPr group, %DH began to recover to normal after the PRPr injection and was restored to 95.5% at week 16. The MRI-modified Pfirrmann grade of the PRPr group was significantly lower than that of the saline group (P < 0.01). Histological analyses showed progressive degenerative changes, including reduction of the NP area and condensation of the matrix in the saline and PRPr groups. The histological score of the PRPr group was significantly lower than that of the saline group (P < 0.01). CONCLUSIONS: PRPr has great potential to enhance the regeneration of degenerated rabbit IVDs induced by condoliase. The results of this preclinical study suggest that PRPr injection therapy may be indicated for patients with LDH who have poor recovery from disc degeneration after chemonucleolysis treatment with condoliase.

Registration in the supine position improve the accuracy of cup placement in total hip arthroplasty using a portable navigation system.

Portable navigation systems have been developed for use in total hip arthroplasty (THA) in recent years. Although intraoperative registration in the lateral decubitus position or the supine position is need to create the three-dimensional coordinate system, it is not clear which position is appropriate. The purpose of this study was to assess the accuracy of cup placement in primary THA in the lateral decubitus position using an image-free handheld navigation device with registration in the lateral decubitus or the supine position, and clarify which position is appropriate. This retrospective study included 129 consecutive cementless THAs performed using an image-free handheld navigation device in the lateral decubitus position. Registration in the first 68 hips was performed in the lateral decubitus position and the last 61 hips was performed in the supine position. Postoperative cup radiographic inclination and radiographic anteversion were assessed, and the accuracy was compared between the two groups. The mean absolute errors of the postoperative measured inclination and anteversion from the target angles were 3.9° ± 2.2° and 4.8° ± 3.5° in the lateral group and 2.9° ± 2.7° and 3.2° ± 2.7° in the supine group (p < 0.05). The percentage of cups inside Lewinnek's safe zone was 94% in the lateral group and 95% in the supine group (ns). The mean absolute values of navigation error in inclination and anteversion were 3.1° ± 2.1° and 4.2° ± 2.8° in the lateral group and 2.3° ± 2.0° and 3.1° ± 2.4° in the supine group (p < 0.05 and p < 0.05). Registration in the supine position improved the accuracy of cup insertion compared with the lateral decubitus position in THA using an image-free handheld navigation device in the lateral decubitus position.

Histological Assessment of Synovial Sarcoma Before and After TCR-T Cell Therapy and Cryoablation: A Case Report.

BACKGROUND/AIM: Cancer/testis antigens (CTAs) are well-known molecular targets with expression restricted to testicular germ cells and malignant tumors. T-cell receptor (TCR)-engineered T-cell (TCR-T) therapy against CTAs in patients with sarcoma has shown substantial progress, but resistance to TCR-T therapy remains a critical problem. In this report, we present a case of synovial sarcoma treated with TCR-T therapy targeting the New York-esophageal squamous cell carcinoma (NY-ESO)-1 protein. Histological findings were compared before and after TCR-T therapy and before and immediately after cryoablation. CASE REPORT: A 68-year-old man received additional wide resection for synovial sarcoma in the left leg. Due to multiple metastases, he was enrolled in a clinical trial of TCR-T therapy for NY-ESO-1. The tumor demonstrated a 34.9% reduction in diameter. However, disease progression occurred by day 84 after TCR-T therapy. Six months after disease progression, cryoablation was performed for right posterior rib lesion and tumor specimens were obtained by needle biopsy both before and immediately after cryoablation. Ten months after the diagnosis of disease progression, the patient died. Expression levels of NY-ESO-1, human leukocyte antigen, and immune checkpoint proteins remained unchanged before and after TCR-T therapy. Beta catenin was up-regulated in recurrent tumor tissues after TCR-T therapy compared to levels observed before TCR-T therapy. Immediately after cryoablation, immunoreactivity for NY-ESO-1 showed a slightly reduction. CONCLUSION: Up-regulation of beta-catenin in synovial sarcoma with recurrence after TCR-T therapy may be involved in T-cell exclusion and resistance to TCR-T therapy. Needle biopsy after cryoablation can be performed with sufficient pathological diagnostic accuracy including immunostaining.

Clinical Outcome in Patients With High-grade Soft-tissue Sarcoma Receiving Prosthetic Replacement After Tumor Resection of the Lower Extremities: Tokai Musculoskeletal Oncology Consortium Study.

AIM: This multicenter retrospective study aimed to clarify the surgical and oncological outcomes of patients with high-grade soft tissue sarcoma (STS) who underwent prosthetic replacement reconstruction after lower extremity tumor resection. PATIENTS AND METHODS: We retrospectively collected the data of 27 patients with high-grade STS. The mean follow-up duration after prosthetic replacement was 44.7 months. RESULTS: The mean age at surgery was 63 years. The mean tumor size was 16 cm. For reconstruction, proximal femur replacement was performed in 15 patients, distal femur replacement in six, and total femur replacement in six. The major complications were infections in nine patients and aseptic loosening in four. Nine patients developed local recurrence. The cause of revision surgery was infection in five patients, aseptic loosening in three, and metal allergy in one. The 5-year prosthetic survival rate was 51.1%. At the final follow-up, amputation was performed in five patients. The 5-year limb salvage rate was 76.8%. The mean functional score of the 25 patients who could be assessed was 16.0 (53%). Of the 27 patients, five were excluded from the survival analysis because they underwent prosthetic replacement for local recurrence. The 5-year overall survival rate in the remaining 22 patients was 45.3%. CONCLUSION: We identified a high rate of surgical complications and poor survival in patients with high-grade STS who underwent tumor resection and reconstruction using prosthetic replacement of the lower extremities, although limb salvage was achieved in 81.5% of the patients. Careful follow-up is needed for surgical complications and oncological events after surgery.

Relationship between oral frailty and locomotive syndrome in working-age individuals: a cross-sectional survey of workers in Japan.

BACKGROUND: Although the relationship between oral and physical frailty in older adults has been investigated, few studies have focused on the working-age population. This study examined the relationships of the number of remaining teeth and masticatory ability, i.e., signs of oral frailty, with locomotive syndrome (LS) in the working-age population. METHODS: The number of remaining teeth, masticatory ability, and presence of LS in 501 participants from four companies were examined. The relationships between the number of remaining teeth groups (≥ 20 teeth or ≤ 19 teeth) and LS and between the masticatory ability groups (high or low) and LS were examined. A binomial logistic regression analysis was conducted using LS from the stand-up test as the objective variable and the two subgroups based on the number of remaining teeth and potential crossover factors as covariates. RESULTS: The analysis included 495 participants (354 males and 141 females; median age, 43 years). The median number of remaining teeth among the participants was 28, and 10 participants (2.0%) had ≤ 19 teeth. The mean masticatory ability values were 39.9 for males and 37.7 for females, and 31 participants (6.3%) had low masticatory ability. In the stand-up test, those with ≤ 19 teeth had a higher LS rate than those with ≥ 20 teeth. The odds ratio for LS in the group with ≤ 19 remaining teeth was 5.99, and the confidence interval was 1.44-24.95. CONCLUSIONS: The results confirmed signs of oral frailty in the working-age population. Further, the number of remaining teeth possibly affects standing movement. Thus, oral frailty is associated with LS in the working-age population.