Correction: MicroRNA-329-3p inhibits the Wnt/ß-catenin pathway and proliferation of osteosarcoma cells by targeting transcription factor 7-like 1.

[This corrects the article DOI: 10.32604/or.2023.044085.].

MicroRNA-329-3p inhibits the Wnt/ß-catenin pathway and proliferation of osteosarcoma cells by targeting transcription factor 7-like 1.

An important factor in the emergence and progression of osteosarcoma (OS) is the dysregulated expression of microRNAs (miRNAs). Transcription factor 7-like 1 (TCF7L1), a member of the T cell factor/lymphoid enhancer factor (TCF/LEF) transcription factor family, interacts with the Wnt signaling pathway regulator ß-catenin and acts as a DNA-specific binding protein. This study sought to elucidate the impact of the interaction between miR-329-3p and TCF7L1 on the growth and apoptosis of OS and analyze the regulatory expression relationship between miRNA and mRNA in osteosarcoma cells using a variety of approaches. MiR329-3p was significantly downregulated, while TCF7L1 was considerably up-regulated in all examined OS cell lines. Additionally, a clinical comparison study was performed using the TCGA database. Subsequently, the regulatory relationship between miR-329-3p and TCF7L1 on the proliferation and apoptosis of OS cells was verified through in vitro and in vivo experiments. When miR-329-3p was transfected into the OS cell line, the expression of TCF7L1 decreased, the proliferation of OS cells was inhibited, the cytoskeleton disintegrated, and the nucleus condensed to form apoptotic bodies. The expression of proteins that indicate apoptosis increased simultaneously. The cell cycle was arrested in the G0/G1 phase, and the G1/S transition was blocked. The introduction of miR-329-3p also inhibited downstream Cyclin D1 of the Wnt pathway. Xenograft experiments indicated that the overexpression of miR-329-3p significantly inhibited the growth of OS xenografts in nude mice, and the expression of TCF7L1 and c-Myc in tumor tissues decreased. MiR-329-3p was significantly reduced in OS cells and played a suppressive role in tumorigenesis and proliferation by targeting TCF7L1 both in vitro and in vivo. Osteosarcoma cell cycle arrest and pathway inhibition were observed upon the regulation of TCF7L1 by miR-329-3p. Summarizing these results, it can be inferred that miR-329-3p exerts anticancer effects in osteosarcoma by inhibiting TCF7L1.

Exploring the extension quantities of a medial collateral ligament pie-crusting model using a finite element method.

Medial collateral ligament (MCL) pie-crusting can balance the soft tissue during total knee arthroplasty but requires more studies with the finite element method (FEM). We have developed three models of MCL pie-crusting utilizing FEM, treating the MCL in the following ways: (1) as a singular elastic body with both ends attached to the bone (model A), (2) as 19 bundled elastic bodies, each attached to both ends of the bone (model B), and (3) as 19 bundled elastic bodies with an adhesive component in the gap, attached to both ends of the bone (model C). The pie-crusting model was created by adding a cut around the center of each model. The left side of the model was fixed and forces of 80 and 120 N in the positive direction of the x-axis were applied. Model A was extended by 0.0068 and 0.010 mm for approximately 10 punctures. Model B-2 was extended by 1.34 and 2.01 mm, approximately twice as much as model B-1. Model C was extended by 0.34 and 0.50 mm for every 10 punctures added. These findings clarify that the model composed of aggregates of fibers with adhesive parts (model C) is suitable for MCL pie-crusting analysis.

Gait analysis of a patient after femoral nerve and malignant soft tissue tumor resections: a case report.

BACKGROUND: Malignant femoral soft tissue tumors are occasionally resected together with the femoral nerves, but this can cause loss of knee extensor muscle activity. To the best of our knowledge, no previous reports have detailed the gait analysis of such cases in combination with electromyography. Herein, we report the gait analysis of a patient who underwent left groin synovial sarcoma and left femoral nerve resection 12 years ago. CASE PRESENTATION: We analyzed the gait of a 38-year-old man who was able to walk unaided after the resection of a synovial sarcoma in the left groin together with the ipsilateral femoral nerve. The muscle activities of the affected medial (MH) and lateral hamstrings (LH), and lateral heads of the gastrocnemius (GL) were increased during 50-75% of the stance phase. The hip flexion angle of the affected limb was smaller, and the ankle plantar flexion angle of the affected limb was larger than that of the non-affected limb. This means that in the affected limb, the hip and ankle angles were adjusted to prevent knee collapse, and the MH, LH, and GL muscles contributed in the mid- and late-stance phases. Moreover, we found that the hamstring and gastrocnemius of the affected limb worked together to keep the ipsilateral knee extended in the mid-stance phase and slightly flexed in the late-stance phase. CONCLUSIONS: Patients capable of walking after femoral nerve resection may control their hamstrings and gastrocnemius muscles collaboratively to prevent ipsilateral knee collapse in the mid- and late-stance phases.

Two Healthy Elderly Females with Contemporaneous Subchondral Insufficiency Fractures of Bilateral Femoral Heads: A Case Report.

Introduction: Unilateral subchondral insufficiency fractures (SIF) of the femoral head have been reported in many cases; however, bilateral cases occurring simultaneously are very rare. Case Report: We report two cases of relatively active elderly females (aged 73 and 67 years), in which bilateral hip pain appeared simultaneously without any specific triggers. There were no notable lifestyle or medication histories. Imaging and histopathology of the bone excised surgically supported the diagnosis. In Case 1, there was a decrease in bone mineral density and poor congruency between the femoral head and acetabulum. In Case 2, the posterior tilt of the pelvis with aging decreased coverage of the femoral head, and the poor congruency between the femoral head and acetabulum was thought to have contributed to uneven distribution and increased stress in the loading zone. Conclusion: We encountered two unusual cases with contemporaneous bilateral SIF in the elderly. In recent years, the number of highly active elderly people has increased with the increase in healthy life expectancy. The combined effect of factors such as bone fragility, posterior pelvic tilt, and high activity level likely caused bilateral SIFs, and we should be careful as we expect to see an increase in such cases in the future.

Effectiveness of gelatin matrix with human thrombin for reducing blood loss in palliative decompressive surgery with posterior spinal fusion for metastatic spinal tumors.

BACKGROUND: This study aimed to investigate the effect of gelatin matrix with human thrombin (GMHT) on blood loss and survival time in patients with metastatic spinal tumors treated with palliative decompression surgery with posterior spinal fusion. METHODS: We retrospectively reviewed 67 consecutive patients with metastatic spinal tumors who underwent palliative decompression surgery with posterior spinal fusion. We compared patients in whom GMHT was not used during surgery with those in whom GMHT was used. The following baseline characteristics were evaluated: age, height, weight, sex, metastatic tumor diagnosis, medical history, use of antiplatelet drug, use of anticoagulant drug, use of NSAIDs, smoking, preoperative PLT value, preoperative APTT, preoperative PT-INR, Karnofsky Performance Status score, Charlson comorbidities index score, the percentage of patients who received perioperative chemotherapy, main tumor level, Frankel category, revised Tokuhashi score, spinal instability neoplastic score (SINS), number of fusion segments, operation time, intraoperative blood loss, drainage blood loss, red blood cell transfusion, hemoglobin level, total protein (TP), albumin values, total blood loss (TBL), hidden blood loss, postoperative bed rest and postoperative survival time. Perioperative complications were assessed. RESULTS: Age, height, weight, sex, metastatic tumor diagnosis, medical history, use of antiplatelet drug, use of anticoagulant drug, use of NSAIDs, smoking, preoperative PLT value, preoperative APTT, preoperative PT-INR, CCI score, main level of tumors, SINS score, preoperative Tokuhashi score and number of fusion segments did not differ significantly between the two groups. Operation time, intraoperative blood loss, postoperative drainage blood loss, and TBL were significantly decreased in the group with GMHT than in the group without GMHT. The total number of perioperative complications was significantly lesser in the group with GMHT than in the group without GMHT. The median postoperative survival time was significantly longer in the GMHT group than in the group without GMHT. CONCLUSION: GMHT should be considered a valid option for the treatment of patients with metastatic spinal tumors with a short life expectancy.

Sequential treatments with TRK inhibitors in a patient with NTRK fusion-positive sarcoma: A case report.

RATIONALE: Precision medicine and tumor-agnostic treatment strategies have recently been promoted for clinical use. One of the most successful treatments in patients with neurotrophic tyrosine receptor kinase (NTRK) fusion-positive tumors is targeting the tropomyosin receptor kinase (TRK) with an inhibitor. The TRK inhibitors, larotrectinib, and entrectinib, have been approved in many countries. Nevertheless, the most effective administration regimen for these TRK inhibitors is uncertain. To date, no reports have shown the efficacy of sequential treatment with larotrectinib and entrectinib in patients with NTRK fusion-positive tumors. In this report, we present a patient with NTRK fusion-positive sarcoma arising from the anterior mediastinum, with tumor progression after 4 months of entrectinib use. The patient took larotrectinib subsequently and maintained disease control for more than 21 months. PATIENT CONCERNS: A 48-year-old female visited a physician because she experienced difficulty in breathing and chest and back pain with no obvious cause 2 months ago. Computed tomography (CT)-guided biopsy was performed at a district general hospital, and histopathological examination revealed a small round cell tumor. She was referred to our hospital, and a second CT-guided biopsy was performed to confirm the pathological diagnosis. Considering the results of the histopathological examination, Ewing sarcoma was suspected, but a specific fusion gene was not detected due to poor quality specimens. DIAGNOSES: After 3 regimens of cytotoxic chemotherapy, biopsy was repeated, and specimens were analyzed using next-generation sequencing. The PHF20-NTRK1 fusion gene was detected, and the tumor was finally diagnosed as an NTRK fusion-positive sarcoma. INTERVENTIONS: She was administered the TRK inhibitor entrectinib, but the tumor started to grow after 4 months of medication, and she stopped taking entrectinib. After 1 cycle of cytotoxic chemotherapy, another TRK inhibitor, larotrectinib, was administered. OUTCOMES: Her stable disease was maintained for more than 21 months. Here, we have shown that sequential administration of both drugs can be effective. LESSONS: In the treatment of NTRK fusion-positive tumors, there are cases in which 2 approved first-generation TRK inhibitors can be used sequentially.

Femoral Bowing Increases Early Postoperative Stress around the Femoral Stem in Humans: A Finite Element Analysis.

Background: This study aimed to clarify the characteristics of stress distribution caused by the placement of tapered wedge stems in bowed femurs compared with that in normal femurs and the effect of varus stem placement. Methods: Models with normal and enhanced bowing were created from the right-side computed tomography data of a 17-year-old woman with the least bowing among 40 participants who underwent anterior cruciate ligament reconstruction or operative treatment for trauma in our hospital between January 2017 and May 2018. Finite element analysis was performed, assuming the tapered wedge stem was placed in the neutral and varus positions. Results: Varus stem placement on a femur with normal bowing showed a deviation and increase of von Mises stresses in the medial femur. Stem placement on a bowed femur, even when placed in the neutral position, increased stress across the periprosthetic bone. When the stem was placed in the varus position, von Mises stress across the periprosthetic bone increased. Zone 7, with strong bowing, demonstrated 3.6-fold increased stress compared with normal femurs. The maximum tensile principal stress was greatest in zone 6 and increased in zones 3 and 4. Conclusions: Surgeons should assess femoral bowing preoperatively and pay particular attention to intraoperative stem alignment for femurs with high bowing.

Tumor-suppressive microRNA-152 inhibits the proliferation of Ewing's sarcoma cells by targeting CDK5R1.

We elucidated the mechanism through which the reduced expression of miR-152 leads to the overexpression of its target cyclin-dependent kinase-5 activator 1 (CDK5R1) in Ewing's sarcoma (ES) cells and the role of this mechanism in the proliferation of ES cells. To explore possible oncogenic factors in ES, we conducted microarray-based investigation and profiled the changes in miRNA expression and their effects on downstream mRNAs in five ES cell lines and human mesenchymal stem cells (hMSCs). miR-152 was significantly downregulated, while cyclin-dependent kinase-5 activator 1 (CDK5R1) expression was significantly upregulated in all tested ES cells as compared to hMSCs. The overexpression of CDK5R1 led to the activation of CDK5, enabling the phosphorylation of retinoblastoma protein and persistent overexpression of CCNE. Moreover, miR-152 suppressed cell proliferation via cell cycle retardation, and its upregulation reduced tumor size and CCNE expression in tumor tissues. The overexpression of cyclin E (CCNE) has been detected in ES cells, but the detailed mechanisms have not been previously elucidated. These findings identify the miR152-CDK5R1 signaling axis as a critical mechanism for tumorigenesis that may serve as a new therapeutic target in Ewing's sarcoma. We believe that our results will aid in the development of effective treatment strategies for patients with ES.

Dome impaction classification in acetabular fractures: Identifying atypical dome impactions with absence of the gull sign: A retrospective descriptive study.

We aimed to describe variations of dome impaction fractures and their characteristics using a new classification system, to explore the relationship between dome impaction and the gull sign. The present study was a retrospective descriptive study. All 104 cases of acetabular fracture that were treated in our institution from 2013 to 2022 were enrolled. Of these, 22 had dome impaction fractures. The primary outcome variable was to describe the variations and characteristics of dome impaction fractures. They were classified into 3 major subgroups based on reconstructed axial, coronal, and sagittal computed tomography findings: anteromedial, superomedial (SM), and posteromedial. The secondary outcome variable was to explore the relationship between dome impaction on computed tomography findings and the gull sign on plain radiographs. There were 4 cases of anteromedial (18.2%), 13 of SM (59.1%), and 5 of posteromedial (22.7%). There were 15 cases (68.2%) with the gull sign and 7 cases (31.8%) without the gull sign on plain radiographs. Twelve of fifteen cases (80.0%) with the gull sign had dome impaction fractures of the SM type. We found a variety of patterns of dome impaction fracture. Surgeons should be aware of atypical dome impactions not showing the gull sign.

The anti-oncogenic effect of 17-DMAG via the inactivation of HSP90 and MET pathway in osteosarcoma cells.

Heat shock protein (HSP) 90 plays a crucial role in correcting the misfolded three-dimensional structure of proteins, assisting them in folding into proper conformations. HSP90 is critical in maintaining the normal functions of various proteins within cells, as essential factors for cellular homeostasis. Contrastingly, HSP90 simultaneously supports the maturation of cancer-related proteins, including mesenchymal epithelial transition factor (MET) within tumor cells. All osteosarcoma cell lines had elevated MET expression in the cDNA array in our possession. MET, a tyrosine kinase receptor, promotes proliferation and an anti-apoptotic state through the activation of the MET pathway constructed by HSP90. In this study, we treated osteosarcoma cells with an HSP90 inhibitor, 17-demethoxygeldanamycin hydrochloride (17-DMAG), and assessed the changes in the MET signaling pathway and also the antitumor effect of the drug. The cell cycle in osteosarcoma cells administered 17-DMAG was found to be halted at the G2/M phase. Additionally, treatment with 17-DMAG inhibited cell proliferation and induced apoptosis. Inhibition of tumor cell proliferation was also observed in an in vivo model system, mice that were treated with 17-DMAG. Based on the results of this study, we were able to confirm that 17-DMAG promotes inhibition of osteosarcoma cell proliferation and induction of apoptosis by inhibition of MET, a protein highly expressed in osteosarcoma cells. This approach may be useful for the establishment of a new treatment strategy for patients resistant to the standard treatment for osteosarcoma.

Analysis of accuracy of pedicle screw placement in dysplastic pedicles in adolescent idiopathic scoliosis using the pedicle expansion technique with CT-based navigation.

BACKGROUND: This study aimed to study the accuracy of pedicle screw (PS) insertion into dysplastic pedicles in adolescent idiopathic scoliosis (AIS) comparing cannulated screw using the pedicle expansion technique (PET) versus conventional technique. METHODS: Forty-two AIS patients with 766 PSs were evaluated. In total, 236 screws were inserted into dysplastic pedicles: 138 and 98 screws were inserted using the PET (PET group) and standard technique (conventional group), respectively. Both methods used CT-based navigation to determine the insertion point. In the PET, a rigid ball tip feeler was tapped with a mallet to create an insertion route, a guide wire was passed through the tap, the pedicle was enlarged, and then a cannulated PS with a diameter of 4.35 mm was inserted. Postoperative CT was used to compare the accuracy of PS insertion. RESULTS: In total, 23/236 (9.7%) perforations occurred. Regarding overall perforation, there were six (4.3%) and 17 (17.3%) cases in the PET and conventional group, respectively (P = 0.008). In terms of medial perforation, the PET group (n = 2, 1.4%) was significantly better than the conventional group (n = 7, 7.1%) (P = 0.021). In terms of lateral perforation, the PET group (n = 4, 2.9%) was significantly better than conventional group (n = 10, 10.2%) (P = 0.030). Only grade 1 perforation had occurred in the PET group, whereas grades 2 and 3 perforation occurred in the conventional group. CONCLUSION: Use of the PET with CT-based navigation significantly increased the accuracy and safety of PS insertion in dysplastic pedicles in AIS.

Influence of femoral bowing on stress distribution of the proximal femur: a three-dimensional finite element analysis.

BACKGROUND: Whether femoral bowing or its direction has a mechanical effect on the proximal femur is unclear. This study aimed to define the changes in stress distribution in the proximal femur associated with femoral bowing using finite element analysis. METHODS: We created four femoral models: original, entire lateral bowing, entire anterior bowing, and the middle of both (50% anterolateral bowing) from computed tomography data of women with standard bowing. Each model's stress distribution was compared by two-layering the stress distribution under loading conditions during walking. We also evaluated displacement vectors. RESULTS: In all directions of femoral bowing, the stress increased in the femoral neck and the femoral trochanter in the 50% anterolateral bowing. The direction of deformation of the vector for the femoral head increased anteroinferiorly in the 50% anterolateral bowing. CONCLUSIONS: This study showed that the stress distribution at the proximal femur shifted laterally. The high-stress area increased at the femoral neck or trochanter due to increasing femoral bowing. Femoral bowing also increases the anteroinferior vector in the femoral head. This study provides valuable insights into the mechanism of proximal femoral fractures in older adults.

Relationship between perceived and structural leg length discrepancies of patients with hip osteoarthritis dysplasia.

BACKGROUND: Only few studies have been conducted on leg length discrepancy (LLD) in patients with hip osteoarthritis (OA). This study aimed to examine the relationship between perceived LLD (pLLD) and structural LLD (sLLD) in patients with advanced OA and to determine the factors influencing both LLDs. This retrospective study aimed to answer the following questions: (1) are older adults less likely to perceive LLD than younger adults? (2) is there a relationship between pLLD and sLLD? and (3) is pLLD associated with patient satisfaction? HYPOTHESIS: We hypothesized that older adults are less likely to perceive LLD than younger adults. PATIENTS AND METHODS: We recruited 125 patients (102 women and 23 men) with hip OA associated with developmental dysplasia of the hip defined as grade 3 or higher according to the Tönnis classification and excluding contralateral grade 2 or higher. The mean age of the patients was 65.2±11.2 (36-85) years. Before surgery, 2-mm and 5-mm thick plates were placed on the floor on the plantar surface of the short leg to measure pLLD. Preoperative computed tomography (CT) was performed and sLLDs were measured using the 3D planning software ZedHip. The following associated factors were evaluated: age, height, weight, body mass index (BMI), adduction and abduction range of motion (ROM) of the affected hip joint, Crowe classification, standing pelvic inclination in the coronal plane, Cobb angle and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ). RESULTS: The absolute difference between pLLD and sLLD was modestly positively correlated with age (R=0.206; p<0.05) indicating older patients were less prone to perceive LLD. A strong positive correlation was found between pLLD (4.8±7.3mm; range: -37 to 28mm) and sLLD (6.4±7.0mm; range: -29.9 to 23.7mm) (R=0.714, p<0.05). The greater the pLLD, the smaller the hip abduction ROM (24.8±11.6°; range: 0 to 45°) tended to be, while the greater the sLLD, the smaller the hip abduction and adduction ROM (10.3±5.7°; range: 0 to 25°) tended to be (R= -0.259 and R= -0.297, respectively; p<0.05) The clinical significance of this finding is that pLLD may be improved if hip ROM training is performed before surgery. pLLD was significantly smaller in the group without pelvic inclination (8.0±14.1mm; range: -37 to 22mm) than in the group with pelvic inclination to the affected side (6.9±7.5mm; range: -12 to 28mm) and in the group with no inclination to the affected side (7.3±7.6mm; range: -8 to 25mm) (p<0.05) The clinical significance of this finding is that improving pelvic inclination with hip ROM training or muscle stretching may also reduce pLLD. No significant differences were noted between pLLD and JHEQ total scores or subgroups. DISCUSSION: Older patients had less pLLD. Preoperative pLLD was strongly correlated with sLLD but not with patient satisfaction. These results may be useful for conservative treatment of OA, preoperative planning and intraoperative leg length correction. LEVEL OF EVIDENCE: IV; case control study.

Survival rates of different bearing surfaces with the same model of stem in total hip arthroplasty: predictive factors for revision surgery.

INTRODUCTION: Few studies have examined the survival rates of total hip arthroplasty (THA) with the same femoral stem, and the predictive factors leading to the revision of stemmed metal-on-metal (MoM) THA remain unknown. We determined the long-term survival rate of stemmed MoM THA compared with that of metal-on-polyethylene (MoP) bearing THA, the effect of head size and cup placement angle on revision rate, and predictors of revision. MATERIALS AND METHODS: A total of 130 hips in 110 patients who underwent primary THA by the same surgeon were included. M2a-RingLoc with a metal-on-polyethylene bearing (group P, 53 hips), M2a-Taper with MoM bearing (group T, 44 hips), and M2a-Magnum with MoM bearing (group M, 33 hips) were used. The mean age at surgery was 63.1 ± 9.5 years, and the mean postoperative follow-up duration was 133.7 ± 39.1 months. Whole blood metal ion concentrations were measured preoperatively and postoperatively, and magnetic resonance imaging was performed to identify aseptic local tissue reactions (ALTRs). Kaplan-Meier survivorship analysis and multiple logistic regression analysis were performed. RESULTS: The THA survival rate up to the maximum postoperative follow-up period was 96.2% at 173 months, 46.6% at 179 months, and 47.8% at 145 months in groups P, T, and M, respectively, with revision as the endpoint. The stemmed MoM THA recorded a very low survival rate (p < 0.001). The ALTR rates were 70.5% and 63.6% in groups T and M, respectively. The risk factor for revision was the use of MoM bearing, and there was no difference in the results based on the head size in group M. Cobalt levels continued to increase postoperatively, although they were not accurate predictors of revision. CONCLUSIONS: Stemmed MoM THA has a very low survival rate and should be used with caution. It is important to monitor the patient's symptoms and perform appropriate imaging to ensure timely revision.

Relationship between K-line distance and surgical outcome in cases of laminoplasty for cervical ossification of the posterior longitudinal ligament.

Although previous studies indicate that changes in cervical alignment after laminoplasty and dynamic factors influence surgical outcomes of cervical ossification of the posterior longitudinal ligament (OPLL), the relationship between the surgical outcomes, the distance between the kyphosis-line (K-line) and OPLL, and dynamic factors have not yet been quantitatively evaluated. The purpose of the present study was to analyze the relationship between ΔK-line distance and surgical outcomes in cases of laminoplasty for OPLL of the cervical spine. We retrospectively reviewed 46 consecutive patients (33 men and 13 women) with cervical OPLL who underwent laminoplasty. "K-line distance" was measured as the minimum interval between the K-line and OPLL on lateral radiographs. The following factors were analyzed: K-line distance in neutral, flexion, and extension neck positions, ΔK-line distance, preoperative C2-7 range of motion (ROM), preoperative segmental ROM, preoperative C2-7 lordotic angle, occupying ratio of the OPLL, disease duration, preoperative and postoperative Japanese Orthopaedic Association (JOA) score, and recovery rate. Patients were divided into flexion K-line (+) and flexion K-line (-) groups. We then analyzed the influence of the K-line distance on surgical outcomes and conducted multivariate analysis to analyze the factors affecting surgical outcomes. The JOA score recovery rate in the flexion K-line (-) group was significantly lower than that in the flexion K-line (+) group (P = .024). The ΔK-line distance was significantly negatively correlated with the JOA score recovery rate (r = -0.531, P < .001). Additionally, multivariate analysis showed that ΔK-line distance (OR = -2.143, P = .015) was negatively correlated with the JOA score recovery rate. The ΔK-line distance is considered useful for the quantitative evaluation of dynamic factors and static compression factors due to OPLL through the measurement of dynamic radiographic images.

Stress distributions of the short stem and the tapered wedge stem at different alignments: a finite element analysis study.

BACKGROUND: The mechanical effects of stem length reduction and stem alignment on the surrounding femur remain unknown. This study directly compared the stress distribution on the surrounding femur of existing tapered wedge stems and short stems and examined the properties of stress distribution at different stem alignments in three dimensions. METHODS: Finite element analysis was conducted for standing and walking. The cementless stem was appropriately sized to ensure adequate contact with the medial cortical bone line that contours the medullary cavity. The stem neck axis was aligned with the femoral neck axis in the mid-position and placed in 2° of the varus and valgus, 3° of flexion and extension, and 10° and 40° of anteversion. RESULTS: Regardless of stem length, the trend of stress distribution was similar. The short stem generated less stress around the stem than the tapered wedge stem. In the coronal plane, the effect of varus and valgus deflection was small. In the sagittal plane, the stress generated around the stem was higher in the extended position than in the flexed position. In the horizontal plane, the stress generated around the stem was higher when the stem anteversion was smaller. CONCLUSIONS: Depending on the design, short stems can reduce the stress on the surrounding bone, compared to a longer tapered wedge with similar stress distribution. Additionally, a short stem can reduce the effect of the varus position. Stems should be placed to achieve stable initial fixation while noting that stresses increase with extension and reduced anteversion.

Surrogacy analysis of intermediate end-points for overall survival in randomized controlled trials of rhabdomyosarcoma.

Treatment of malignant tumors, such as rhabdomyosarcoma (RMS), can improve overall survival (OS). It is time-consuming and expensive for patients to obtain benefits from randomized controlled trials (RCTs) with OS as the primary end-point. Therefore, another surrogate end-point is necessary; however, there is no report on the surrogacy analysis of RMS. In this study, we performed a systematic review of RCTs, involving patients with newly diagnosed RMS, and 11 RCTs were identified. We performed a meta-analysis to assess the surrogacy of intermediate end-points for OS. The correlations between surrogate end-points and OS were investigated using Spearman's rank correlation coefficient (ρ). The coefficient of determination (R2) was employed to measure the strength of the association. A total of 5183 patients were randomly allocated to 34 treatment groups. A marginal correlation (R2 = 0.281, ρ = 0.445) between the hazard ratios (HRs) for event-free survival (EFS) and OS was observed. In patients with localized RMS, the EFS HR had a weaker correlation with OS HR in the sensitivity analysis than that in the primary analysis. Overall, the surrogacy of EFS for OS cannot be confirmed.

Analysis of rotational deformity correction by lateral lumbar interbody fusion with two-staged anterior-posterior combined corrective fusion surgery for adult degenerative kyphoscoliosis.

The present study is retrospective analysis of consecutively collected data. Lateral lumber interbody fusion (LLIF) is widely used in cases of adult spinal deformities. However, the corrective effects of LLIF cage insertion on the vertebral rotation deformity in the axial plane and the individual effects of LLIF and direct vertebral rotation (DVR) on rotational correction are unclear. To individually examine the corrective effects of LLIF and posterior corrective fusion surgery with direct DVR on vertebral rotation deformities in adult degenerative kyphoscoliosis. We analyzed 21 patients (5 males and 16 females) who underwent two-staged anterior-posterior combined corrective fusion surgery for adult degenerative kyphoscoliosis. Surgical time, blood loss, facet joint osteoarthritis (OA) grade, disc degeneration, cage height, vertebral rotational angle, and various X-ray parameters were investigated as evaluation items. The X-ray parameters showed significant postoperative improvements. The mean vertebral rotation angle was 6.4°â€…±â€…5.2° preoperatively, 3.5°â€…±â€…3.3° after LLIF (P = .014, vs preoperative), and 1.6°â€…±â€…1.7° after posterior corrective fusion surgery with DVR (P = .011, vs preoperative). Correlation analysis between the vertebral rotation angle and various measured values revealed that the vertebral rotation angle after LLIF was correlated with the cage height (r = -0.46, P = .032). The vertebral rotation angle after DVR was correlated with the facet joint OA grade (r = -0.49, P = .018) and the wedge angle after posterior corrective fusion surgery with DVR (R = 0.57, P = .006). We conclude that the effects of rotational deformity correction with LLIF cage insertion and additional posterior corrective fixation with DVR can be useful for correcting vertebral rotation deformities.