Evaluating the Alignment of Artificial Intelligence-Generated Recommendations With Clinical Guidelines Focused on Soft Tissue Tumors.

BACKGROUND: The integration of artificial intelligence (AI), particularly, in oncology, has significantly shifted the paradigms of medical diagnostics and treatment planning. However, the utility of AI, specifically OpenAI's ChatGPT, in soft tissue sarcoma treatment, remains unclear. METHODS: We evaluated ChatGPT's alignment with the Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of soft tissue tumors 2020. Twenty-two clinical questions (CQs) were formulated to encompass various aspects of sarcoma diagnosis, treatment, and management. ChatGPT's responses were classified into "Complete Alignment," "Partial Alignment," or "Nonalignment" based on the recommendation and strength of evidence. RESULTS: ChatGPT demonstrated an 86% alignment rate with the JOA guidelines. The AI provided two instances of complete alignment and 17 instances of partial alignment, indicating a strong capability to match guideline criteria for most questions. However, three discrepancies were identified in areas concerning the treatment of atypical lipomatous tumors, perioperative chemotherapy for synovial sarcoma, and treatment strategies for elderly patients with malignant soft tissue tumors. Reassessment with guideline input led to some adjustments, revealing both the potential and limitations of AI in complex sarcoma care. CONCLUSION: Our study demonstrates that AI, specifically ChatGPT, can align with clinical guidelines for soft tissue sarcoma treatment. It also underscores the need for continuous refinement and cautious integration of AI in medical decision-making, particularly in the context of treatment for soft tissue sarcoma.

Higher association of articular surface destruction with rheumatoid forefoot deformity arising from dislocation of the metatarsophalangeal joints in the lateral column.

BACKGROUND: To evaluate the relationship between the pattern and severity of metatarsophalangeal (MTP) joint dislocation in the lesser toes and severity of joint destruction in rheumatoid forefoot deformities. METHODS: Participants comprised of 13 patients (16 feet) who underwent resection arthroplasty of the metatarsal head of the lesser toes for rheumatoid arthritis of the MTP joints. Correlations between preoperative radiographic findings and histological grades second to fifth metatarsal heads taken intraoperatively were analyzed. RESULTS: In 62 metatarsal heads, complete dislocation of the MTP joint in the lesser toes significantly resulted in severe joint destruction compared to mild or moderate dislocation (P < 0.05). The proportion of severe cartilage damage in MTP joints with complete dislocation was 100 % in the 5th MTP joint, 83.3 % in the 4th MTP joint, and 58.3 % in the 2nd and 3rd MTP joints. Moreover, complete dislocation of the MTP joints in the lateral column showed the most severe joint destruction compared to that in the medial column (P = 0.03). CONCLUSION: Complete dislocation of the MTP joint in the lateral column is related to joint destruction in rheumatoid forefoot deformities.

Radiation therapy improves survival in elderly patients with localized extremity soft tissue sarcoma.

BACKGROUND: This study aims to evaluate the efficacy of radiation therapy in enhancing survival outcomes among elderly patients diagnosed with localized extremity soft tissue sarcomas (STSs). Furthermore, it seeks to explore whether the survival benefits conferred by radiation therapy differ according to tumor characteristics and treatment modalities. METHODS: We conducted a retrospective analysis using the Surveillance, Epidemiology, and End Results (SEER) database to identify patients aged 80 years and older diagnosed with localized extremity STSs. The study assessed 1498 eligible patients, analyzing cancer-specific survival (CSS) and overall survival (OS) through Kaplan-Meier survival analysis and Cox proportional hazards modeling. Propensity score matching was employed to adjust for potential confounders. RESULTS: Among the analyzed patients, 773 patients underwent radiation therapy (Radiation group), while 725 patients either did not receive radiation therapy or it was unknown if they had (No-Radiation group). The 5-year OS rate was 40% in the radiation group compared to 38% in the no-radiation group. After propensity score matching, radiation therapy was associated with a significant improvement in OS (P = 0.005, HR = 0.8, 95% CI 0.7-0.9). Subgroup analyses indicated that patients undergoing primary tumor resection benefited most from radiation therapy in terms of OS. CONCLUSION: Radiation therapy is associated with improved overall survival in elderly patients with localized extremity STSs. These findings suggest that radiation therapy should be considered as a key component of the treatment strategy for this patient population, taking into account individual patient characteristics and comorbidities.

Depletion of b-series ganglioside prevents limb length discrepancy after growth plate injury.

INTRODUCTION: Growth plate damage in long bones often results in progressive skeletal growth imbalance and deformity, leading to significant physical problems. Gangliosides, key glycosphingolipids in cartilage, are notably abundant in articular cartilage and regulate chondrocyte homeostasis. This suggests their significant roles in regulating growth plate cartilage repair. METHODS: Chondrocytes from 3 to 5 day-old C57BL/6 mice underwent glycoblotting and mass spectrometry. Based on the results of the glycoblotting analysis, we employed GD3 synthase knockout mice (GD3-/-), which lack b-series gangliosides. In 3-week-old mice, physeal injuries were induced in the left tibiae, with right tibiae sham operated. Tibiae were analyzed at 5 weeks postoperatively for length and micro-CT for growth plate height and bone volume at injury sites. Tibial shortening ratio and bone mineral density were measured by micro-CT. RESULTS: Glycoblotting analysis indicated that b-series gangliosides were the most prevalent in physeal chondrocytes among ganglioside series. At 3 weeks, GD3-/- exhibited reduced tibial shortening (14.7 ± 0.2 mm) compared to WT (15.0 ± 0.1 mm, P = 0.03). By 5 weeks, the tibial lengths in GD3-/- (16.0 ± 0.4 mm) closely aligned with sham-operated lengths (P = 0.70). Micro-CT showed delayed physeal bridge formation in GD3-/-, with bone volume measuring 168.9 ± 5.8 HU at 3 weeks (WT: 180.2 ± 3.2 HU, P = 0.09), but normalizing by 5 weeks. CONCLUSION: This study highlights that GD3 synthase knockout mice inhibit physeal bridge formation after growth plate injury, proposing a new non-invasive approach for treating skeletal growth disorders.

Elucidation of the association between additional distal femoral resection and extension angle improvement following the actual surgical steps with the Robot-TKA system.

BACKGROUND: This study investigates the association between additional distal femoral resection and improved flexion contracture in total knee arthroplasty (TKA) with a robot-assisted system. Flexion contracture is a common issue in patients with knee osteoarthritis, which causes postoperative complications and functional limitations. This study aims to evaluate the effectiveness of additional bone resection in flexion contracture correction and knee extension angle improvement after the actual surgical steps. METHODS: The study included 11 patients who underwent posterior-stabilized (PS)-type TKA with a robot-assisted system. The surgical technique consisted of precise bone resection and range of motion evaluation using a navigation system. A precut technique was used to facilitate posterior access and remove osteophytes that cause the contracture. The amount of additional distal femoral resection was determined based on the thickness of the insert trial required for achieving full extension. RESULTS: The flexion contracture correction angle and the amount of additional distal femoral resection demonstrated a linear relationship. An average of 2.0° with the standard error (SE) of 0.6° improvement in flexion contracture was observed per 1.0 mm of additional bone resection. The postoperative evaluation demonstrated a significant improvement in knee extension angle, thereby reducing the contracture degree. CONCLUSION: This study was the first to perform the additional distal femoral resection on the living knee, which closely replicates the actual surgical steps. The current study revealed that an additional 1.0 mm of distal femoral resection in PS-type TKA improves knee extension angle by 2.0° (SE 0.6°) within an additional resection range of 1.0 mm to 3.3 mm.

Paradoxical Change in Subchondral Bone Density in the Medial Compartment of the Proximal Tibial Articular Surface After High Tibial Osteotomy: A Detailed Subchondral Bone Density Analysis.

BACKGROUND: High tibial osteotomy (HTO) aims to realign the varus knee to alleviate stress in the medial compartment. However, detailed information on the impact of HTO on stress distribution across the tibiofemoral joint surface still needs to be completely elucidated. PURPOSE/HYPOTHESIS: The present study aimed to analyze the subchondral bone density distribution to validate the alignment threshold causing paradoxical changes. We hypothesized that there would be a paradoxical stress change in the medial compartment beyond a specific threshold for lower limb realignment after HTO. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A retrospective clinical study of 32 knees from 30 patients who underwent medial opening-wedge HTO between 2015 and 2019 was conducted at Hokkaido University Hospital. The subchondral bone density across the tibiofemoral joint was analyzed using computed tomography-osteoabsorptiometry before and after HTO. The high-density area (HDA) within the medial and lateral compartments and their subregions, which were quartered in the coronal plane, was specifically examined. RESULTS: The hip-knee-ankle angle, medial proximal tibial angle (MPTA), joint line obliquity (JLO), and joint line convergence angle significantly changed after HTO (P < .01). The HDA of the medial compartment to the total HDA ratio decreased from 83% to 77%. Paradoxically, the HDA in the most central subregion of the medial compartment increased from 24% to 30%. There were significant differences between MPTA and JLO in patients with and without paradoxical changes in the HDA. MPTA and JLO cutoff values causing paradoxical changes in the HDA were 94° and 4°, respectively. CONCLUSION: There was a paradoxical stress increase in the M4 region at the medial compartment associated with the MPTA and JLO beyond specific thresholds. Therefore, surgical planning should be cautiously performed to prevent overcorrection, which can lead to adverse stress distribution changes.

Analysis of foot-originating malignant bone tumors: Epidemiology, characteristics, and survival outcomes.

BACKGROUND: The study examines the characteristics and outcomes of foot-originating malignant bone tumors via Surveillance Epidemiology and End Results (SEER) database analysis. METHODS: A retrospective review of 14,695 malignant bone tumor cases from 2000 to 2019 was conducted. RESULTS: Of the eligible cases, 147 (2.3 %) were foot-origin tumors, typically smaller and more commonly treated with surgery than those in other locations. These tumors were more frequently treated with surgical resection, with a higher proportion undergoing amputation. In contrast, foot-origin tumors were less often managed with chemotherapy and radiation. Foot-origin tumors exhibited higher survival rates compared to non-foot-origin tumors as shown in univariate analysis, although multivariate analysis did not reflect significant differences. CONCLUSION: Foot-originating malignant bone tumors tend to be smaller and are frequently surgically treated, correlating with favorable survival outcomes. These findings point to early detection as a potential factor in the improved survival rates, not necessarily the tumor's origin.

Simultaneous medial closing wedge distal femoral varus osteotomy and double-bundle anterior cruciate ligament reconstruction in the symptomatic femoral valgus deformity: A case report.

Distal femoral varus osteotomy (DFVO) is a widely recognized surgical procedure used to address valgus malalignment in patients with knee joint disorders. However, it still remains unclear whether anterior cruciate ligament (ACL) reconstruction can be performed in a single procedure along with DFVO. Herein, we present a 73-year-old female patient who developed lateral osteoarthritis of the knee with valgus alignment due to chronic ACL deficiency following a twisting injury during skiing. She was physiologically very active, and strongly demanded to return to sports. We performed a combined procedure involving a medial closing wedge DFVO using an anatomical locking plate, along with double-bundle ACL reconstruction. The postoperative radiograph confirmed successful correction of knee alignment, specifically achieving varus alignment with precise conformance of the anatomical plate to the medial contour of the distal femur following the osteotomy. The patient resumed her previous sports activities without experiencing knee pain. The operated knee demonstrated restored anterior stability, as indicated by negative Lachman test results, and regained full range of motion. Both the Knee Injury and Osteoarthritis Outcome Score and the 2011 Knee Society score demonstrated continuous postoperative improvements over the three-year follow-up period, indicating positive functional outcomes and joint preservation. To the best of our knowledge, this is the first case of medial closing wedge DFVO with anatomic double-bundle ACL reconstruction in the symptomatic femoral valgus deformity with chronic ACL deficiency in the literature.

Glycosphingolipids in Osteoarthritis and Cartilage-Regeneration Therapy: Mechanisms and Therapeutic Prospects Based on a Narrative Review of the Literature.

Glycosphingolipids (GSLs), a subtype of glycolipids containing sphingosine, are critical components of vertebrate plasma membranes, playing a pivotal role in cellular signaling and interactions. In human articular cartilage in osteoarthritis (OA), GSL expression is known notably to decrease. This review focuses on the roles of gangliosides, a specific type of GSL, in cartilage degeneration and regeneration, emphasizing their regulatory function in signal transduction. The expression of gangliosides, whether endogenous or augmented exogenously, is regulated at the enzymatic level, targeting specific glycosyltransferases. This regulation has significant implications for the composition of cell-surface gangliosides and their impact on signal transduction in chondrocytes and progenitor cells. Different levels of ganglioside expression can influence signaling pathways in various ways, potentially affecting cell properties, including malignancy. Moreover, gene manipulations against gangliosides have been shown to regulate cartilage metabolisms and chondrocyte differentiation in vivo and in vitro. This review highlights the potential of targeting gangliosides in the development of therapeutic strategies for osteoarthritis and cartilage injury and addresses promising directions for future research and treatment.

Amputation surgery associated with shortened survival in patients with localized extremity bone sarcoma.

Background: This study assesses survival rates among patients with localized extremity bone sarcoma who have undergone amputation, pinpointing subpopulations that are disproportionately affected by amputation-related survival disparities. Methods: Examination of data was conducted using the Surveillance, Epidemiology, and End Results (SEER) program, analyzing records of 3765 patients diagnosed with localized extremity bone sarcoma between 2000 and 2019. Of these, 857 received amputations (Amputation cohort), and 2908 underwent limb-sparing surgeries. Propensity score matching, considering demographic and clinical features, was utilized to ensure a fair comparison. Results: Following propensity score matching, the study focused on 1714 cases. The Amputation cohort was observed to have significantly poorer survival rates (Cancer-Specific Survival [CSS]: Hazard Ratio [HR] = 1.28, 95% Confidence Interval [CI]: 1.05-1.55; Overall Survival [OS]: HR = 1.37, 95% CI: 1.15-1.63). Subsequent subgroup analysis indicated that individuals with tumors exceeding 8 cm in size or those located in the lower limbs were notably at a higher risk of shortened survival (for tumors >8 cm - CSS: HR = 1.32, 95% CI: 1.02-1.71; OS: HR = 1.39, 95% CI: 1.09-1.76; for lower limb tumors - CSS: HR = 1.25, 95% CI: 1.01-1.54; OS: HR = 1.33, 95% CI: 1.11-1.61). Conclusions: Our findings demonstrate that patients diagnosed with localized extremity bone sarcoma undergoing amputation exhibit lower survival rates, especially in cases involving tumors of greater size or those situated in the lower limbs. In patient groups where amputation is inevitable, careful follow-up is required after surgical intervention.

Bone Density Distribution Pattern in the Lateral Wall of the Femoral Intercondylar Notch: Implications for the Direct Insertion of the Femoral ACL Attachment.

Background: The ideal position of the femoral bone tunnel in the anterior cruciate ligament (ACL) is controversial. The functional importance of the ACL fiber varies depending on where it is attached to the femur. Functionally important fibers can cause high mechanical stress on the bone, and the Wolff law predicts that bone mineral density will increase at high mechanical stress sites. Purpose/Hypothesis: The purpose of this study was to use computed tomography imaging to determine the distribution pattern of bone density in the lateral intercondylar wall. It was hypothesized that the high-density area (HDA) of the lateral intercondylar wall would reflect the functional insertion of the ACL as reported in previous anatomic studies. Study Design: Descriptive epidemiology study. Methods: Data from 39 knees without ACL injuries were retrospectively collected. The HDA of the lateral intercondylar wall was defined as the region containing the top 10% of the radiodensity values. The shape of the HDA was approximated as an ellipse, and the quadrant method was used to determine the center of the ellipse. The association between the ratio of the minor axis to the major axis of the ellipse and background characteristics was investigated. Results: According to the quadrant method, the center of the HDA ellipse was 33.6% in the deep-shallow direction and 23.4% in the high-low direction. The center of the ellipse was comparable to the anatomic center of the ACL footprint, as previously reported. The ratio of the minor axis to the major axis of the ellipse was 0.58 (95% CI, 0.54-0.62). There was a significant negative correlation between the ratio of the minor axis to the major axis of the HDA ellipse and the posterior tibial slope (r = -0.38, P = .02). Conclusion: The center of the HDA ellipse was found to be similar to the anatomic center of the ACL footprint. Considering the mechanical stress responses in bone, the HDA of the lateral intercondylar wall has the potential to represent the ACL insertion, especially functional insertion.

The alterations in nerve growth factor concentration in plasma and synovial fluid before and after total knee arthroplasty.

Total knee arthroplasty (TKA) is an effective procedure for pain relief; however, the emergence of postsurgical pain remains a concern. In this study, we investigated the production of nerve growth factor (NGF) and mediators that affect NGF production and their function in the synovial fluid and plasma after TKA. This study included 19 patients (20 knees) who had rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and knee osteoarthritis (OA) who underwent TKA, categorized into OA and non-OA groups. The levels of NGF, inflammatory cytokines, and lipid mediators were analyzed before and after surgery. The intraoperative synovial fluid NGF concentration was more than seven times higher in the non-OA group than in the OA group. The intra-articular NGF levels increased significantly by more than threefold postoperatively in the OA group but not in the non-OA group. Moreover, the levels of inflammatory cytokines and lipid mediators were increased in the synovial fluid of both groups. The intra-articular cytokines or NGF concentrations positively correlated with postoperative pain. Targeted NGF control has the potential to alleviate postsurgical pain in TKA, especially in patients with OA, emphasizing the importance of understanding NGF dynamics under different knee conditions.

Surgical Resection of Primary Tumor for Bone Metastatic Breast Cancer Patients at Initial Presentation.

BACKGROUND/AIM: The purpose of this study was to investigate whether primary tumor resection in patients with bone metastatic breast cancer has an impact on survival using the Surveillance, Epidemiology, and End Results database, considering subtype classification. PATIENTS AND METHODS: We included all female patients with bone metastatic breast cancer at initial presentation between 2010 and 2016 with known hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) statuses. Cases showing unknown cause of death or unknown HR/HER2 status were excluded. Survival analysis was performed using Cox proportional hazards modeling to calculate hazard ratios (HZR). RESULTS: Of the 13,450 patients included in this study, 2,073 patients were HR+/HER2+, 8,597 patients were HR+/HER2-, 797 patients were HR-/HER2+, and 1,182 patients were HR-/HER2- (triple-negative). Five-year overall survival (OS) rate was 34.5% in HR+/HER2+, 26.0% in HR+/HER2-, 29.2% in HR-/HER2+ and 8.0% in triple-negative. Triple-negative patients showed the worsen OS [HR+/HER2+: HZR=2.1, 95% confidence interval (CI)=1.9-2.3; HR+/HER2-: HZR= 2.4, 95%CI=2.2-2.6; HR-/HER2+: HZR=1.5, 95%CI=1.3-1.6]. After excluding patients who died within six months, primary tumor resection prolonged survival in each subtype classification except HR-/HER2+. CONCLUSION: Patients with triple-negative bone metastatic breast cancer showed unfavorable survival. Primary tumor resection prolonged survival in each subtype except for HR-/HER2+.

Articular cartilage corefucosylation regulates tissue resilience in osteoarthritis.

This study aimed to investigate the glycan structural changes that occur before histological degeneration in osteoarthritis (OA) and to determine the mechanism by which these glycan conformational changes affect cartilage degeneration. An OA model was established in rabbits using mannosidase injection, which reduced high-mannose type N-glycans and led to cartilage degeneration. Further analysis of glycome in human OA cartilage identified specific corefucosylated N-glycan expression patterns. Inhibition of N-glycan corefucosylation in mice resulted in unrecoverable cartilage degeneration, while cartilage-specific blocking of corefucosylation led to accelerated development of aging-associated and instability-induced OA models. We conclude that α1,6 fucosyltransferase is required postnatally to prevent preosteoarthritic deterioration of articular cartilage. These findings provide a novel definition of early OA and identify glyco-phenotypes of OA cartilage, which may distinguish individuals at higher risk of progression.

The Influence of Patello-Femoral Overstuffing After Modular Unlinked Bicompartmental Knee Arthroplasty (BiKA) for Medial Tibio-Femoral and Patello-Femoral Osteoarthritis of the Knee.

BACKGROUND: The factors affecting results after bicompartmental knee arthroplasty (BiKA) have not been fully elucidated. This major ligament-preserving procedure may be more susceptible to overstuffing of the patello-femoral (PF) joint than the major ligament-sacrificing total knee arthroplasty. Currently, we investigated the effect of PF overstuffing after BiKA on its clinical outcome. METHODS: There were 71 patients (74 knees) who underwent modular unlinked BiKA at our clinic who had a follow-up of 5 to 9 years. Final follow-up results were assessed by evaluating knee range of motion, the 2011 Knee Society Score (2011KSS), Japanese Knee Osteoarthritis Measure, and radiological findings. The degree of postoperative PF overstuffing was evaluated by computed tomography and magnetic resonance images for 55 knees, and the correlation between the degree of overstuffing and postoperative clinical results were examined. RESULTS: Overall clinical results improved significantly after surgery without any revision cases. The X-ray measurements showed the improved coronal alignments and the appropriate implant installation angles. Higher degree of postoperative PF overstuffing caused by insufficient amount of osteotomy on the anterior surface of the femur correlated with worse postoperative total 2011KSS at 2 years after surgery (Spearman's rank correlation coefficient (rs) = -0.387, P = .004), as opposed to no correlation at the time of the final follow-up (Spearman's rank correlation coefficient = 0.068, P = .623). CONCLUSION: Modular unlinked BiKA provided patients with a high level of satisfaction and functional improvement over 5 to 9 years postoperatively. However, because PF overstuffing affects initial patient satisfaction, the amount of osteotomy should be determined carefully during the surgery.

Amputation surgery associated with shortened survival in patients with localized soft tissue sarcoma.

BACKGROUND: The objectives of this study were to clarify whether localized extremity soft tissue sarcoma (STS) patients who underwent amputation surgery experienced worsened survival and to identify those patients for whom amputation surgery worsened survival. METHODS: Using the Surveillance, Epidemiology, and End Results database, we identified 8897 patients with localized extremity STS between 1983 and 2016. Of these 6431 patients, 733 patients underwent amputation surgery (Amputation group), and 5698 underwent limb-sparing surgery (Limb-sparing group). RESULTS: After adjusting for patient background by propensity score matching, a total of 1346 patients were included. Patients in the Amputation group showed worsened survival (cancer-specific survival (CSS): hazard ratio (HR) = 1.42, 95% confidence interval (CI) 1.15-1.75, overall survival (OS): HR = 1.41, 95%CI 1.20-1.65). In subclass analysis, patients with high-grade STS, spindle cell sarcoma and liposarcoma in the Amputation group showed shortened survival (high-grade-CSS: HR = 1.44, 95%CI 1.16-1.77, OS: HR = 1.38, 95%CI 1.18-1.62; spindle cell sarcoma-CSS: HR = 4.75, 95%CI 1.56-14.4, OS: HR = 2.32, 95%CI 1.45-3.70; liposarcoma-CSS: HR = 2.91, 95%CI 1.54-5.50, OS: HR = 2.32, 95%CI 1.45-3.70). CONCLUSIONS: Survival was shortened in localized extremity STS patients who received amputation surgery.

Bone metastatic cancer of unknown primary at initial presentation.

INTRODUCTION: Cancer of unknown primary (CUP) is a challenging malignancy. The purpose of this study was to investigate the clinical characteristics and prognosis of bone metastatic CUP using the population-based Surveillance, Epidemiology, and End Results (SEER) database. METHODS: From the SEER database, we identified 1908 patients with bone metastatic CUP at initial presentation between 2010 and 2018. Histology was subdivided following International Classification of Diseases for Oncology codes as Adenocarcinoma, Squamous cell, Neuroendocrine, or Carcinoma not otherwise specified (NOS). Cox proportional hazard modeling was applied using factors of age, sex, ethnicity, histological subtype, and therapeutic intervention. RESULTS: Among the 1908 patients, histology was Neuroendocrine in 240 patients, Squamous cell in 201 patients, Adenocarcinoma in 810 patients and NOS in 657 patients. In each subtype, patients tended to be predominantly male and white. Chemotherapy was introduced for 28% of patients and radiation for 34% in the entire cohort. Survival in patients with bone metastatic CUP was unfavorable, with a median survival of 2 months. Among the histological subtypes, Adenocarcinoma showed shorter survival than the other groups. In addition, treatment interventions such as chemotherapy and radiation therapy prolonged survival, particularly for Squamous cell, Adenocarcinoma and NOS, but not for Neuroendocrine. DISCUSSION: Bone metastatic CUP showed extremely poor prognosis, but treatment interventions such as chemotherapy and radiation generally offered survival benefits. Further randomized clinical research is needed to confirm the present results.

Atelocollagen-associated autologous chondrocyte implantation for the repair of large cartilage defects of the knee: Results at three to seven years.

BACKGROUND: Recently, various types of engineered autologous chondrocyte implantation (ACI) have been developed. Atelocollagen-associated ACI (A-ACI) is the only ACI procedure covered by Japanese Health Insurance since 2013. The indications of the A-ACI are traumatic cartilage defects and osteochondral dissecans (OCD) for knee joints. PURPOSE: To evaluate midterm clinical results after A-ACI for the treatment for full-thickness cartilage defects of the knee. METHODS: Thirteen consecutive patients who underwent A-ACI between 2014 and 2018 had been prospectively enrolled in this study. There were 11 men and 2 women with a mean age of 34 years at the time of surgery. The causes of the cartilage defect were trauma in 10 knees and OCD in 3 knees. The total number of lesions was 15, which were comprised of the medial femoral condyle in 5 knees, the lateral femoral condyle in 5 knees, and the femoral trochlea in 5 knees. The mean size of the lesion was 5.3 cm2. Each knee was clinically and radiologically evaluated preoperatively and postoperatively. RESULTS: The mean Lysholm score improved significantly from 74.0 points to 94.0 points (p = 0.008) and each subscale in Knee injury and Osteoarthritis Outcome Score improved significantly (p < 0.001) at the mean final follow-up period of 51 months (range, 36-84 months). The magnetic resonance observation of cartilage repair tissue 2.0 score at the mean follow-up of 38 months was significantly higher than that at 2 months postoperatively (p = 0.014). According to the International Cartilage Repair Society (ICRS) grading scale, 3 knees were graded as normal, 3 knees as nearly normal, and 1 knee as severely abnormal in second-look arthroscopic evaluation at a mean of 22 months (range, 8-41 months) after A-ACI. CONCLUSION: The present study showed a significant subjective and objective clinical improvement in the A-ACI for large cartilage defects of the knee at a mean follow-up of 51 months (range, 36-84 months).

Magnetic Resonance Water Tracer Imaging Using 17 O-Labeled Water.

ABSTRACT: Magnetic resonance imaging (MRI) is a crucial imaging technique for visualizing water in living organisms. Besides proton MRI, which is widely available and enables direct visualization of intrinsic water distribution and dynamics in various environments, MR-WTI (MR water tracer imaging) using 17 O-labeled water has been developed, benefiting from the many advancements in MRI software and hardware that have substantially improved the signal-to-noise ratio and made possible faster imaging. This cutting-edge technique allows the generation of novel and valuable images for clinical use. This review elucidates the studies related to MRI water tracer techniques centered around 17 O-labeled water, explaining the fundamental principles of imaging and providing clinical application examples. Anticipating continued progress in studies involving isotope-labeled water, this review is expected to contribute to elucidating the pathophysiology of various diseases related to water dynamics abnormalities and establishing novel imaging diagnostic methods for associated diseases.

Assessing knee joint biomechanics and trunk posture according to medial osteoarthritis severity.

During progression of knee osteoarthritis (OA), gait biomechanics changes three-dimensionally; however, its characteristics and trunk posture according to OA severity remain unknown. The present study investigated three-dimensional knee joint biomechanics and trunk posture according to knee OA severity. Overall, 75 patients (93 knees) with medial knee OA [Kellgren-Lawrence grade ≥ 2, grade 2: 20 patients with 24 knees (mean 60.0 years old); grade 3: 25 with 28 knees (mean 62.0 years old); grade 4: 30 with 41 knees (mean 67.9 years old)] and 14 healthy controls (23 knees, mean 63.6 years old) underwent gait analysis using an optical motion capture system and point cluster technique. In grade 2 knee OA, the relative contribution of the knee adduction moment (KAM) increased significantly (P < 0.05), and that of the knee flexion moment decreased (P < 0.05) prior to significant progression of varus knee deformity. Grade 3 knee OA showed significant exacerbation of varus knee deformity (P < 0.01) and KAM increase (P < 0.001). The maximum knee extension angle decreased (P < 0.05) and trunk flexion increased during gait in grade 4 knee OA (P < 0.001). Our study clarified the kinematics and kinetics of medial knee OA with trunk flexion according to severity. Kinetic conversion occurred in grade 2 knees prior to progression of varus deformities, knee flexion contractures, and sagittal imbalance during gait in patients with severe knee OA.