The Karnofsky Performance Status at Discharge Is a Prognostic Indicator of Life Expectancy in Patients With Glioblastoma.

Background Glioblastoma (GBM) is the most frequent invasive brain tumor and a rapidly progressive disease with a poor prognosis that predominantly affects middle-aged and older adults. The relationship between daily functioning and prognosis in patients with GBM will become more important as advances in multimodality treatment are expected to increase the number of long-term survivors. Methods Sixty-seven patients were initially diagnosed with GBM at our hospital between December 2013 and December 2022. All patients were divided into two groups: those who survived for one year or longer from the date of discharge (Group A) and those who died within one year from the date of discharge (Group B). Muscle strength, nutritional status, and Karnofsky Performance Status (KPS) were examined upon admission (p1), post-surgery (p2), and discharge (p3), and their relationships with prognosis were investigated. Results Group A was significantly younger than Group B, with a significant difference in the total radiation dose. There were no significant differences in the anatomical tumor location, whether the tumor occurred on the left or right side, or tumor size. KPS at discharge (p3) and the degree of improvement in the KPS between p1 and p3 were associated with a good prognosis. Conclusions The KPS varies throughout the treatment. When considering the KPS as a prognostic indicator, the KPS at discharge is the most important, given the structure of the disability and the course of treatment for GBM.

Factors Influencing the Postoperative Flexion Angle in Cruciate-Sacrificing Rotating Platform of Total Knee Arthroplasty.

BACKGROUND: Various factors affect the improvement of range of motion (ROM) after total knee arthroplasty (TKA). However, there are few reports specific to cruciate-sacrificing rotating platform (CSRP) TKA. In this study, factors affecting postoperative ROM improvement of CSRP TKA were investigated. METHODS: The study included 79 patients with knee osteoarthritis who underwent unilateral CSRP TKA at our institution. The group with an improvement of 5° or more (Δflexion angle) than the preoperative was defined as the good Δflexion group (38 knees), and that with less than 5° was defined as the poor Δflexion group (41 knees). The assessments were performed one day before and one year after surgery. Factors including rest and walking pain, knee flexion and extension angle, isometric knee extension strength, the five subscales of Knee injury and Osteoarthritis Outcome Score (KOOS), α, ß, γ and δ angles, femoro-tibial angle (FTA), and condylar twist angle were assessed. Unpaired t-test, Mann-Whitney U test, and Chi-square test were used to test differences between the good and poor Δflexion groups. Multiple logistic regression examined the association between each factor and the dependent variables (good Δflexion or poor Δflexion). RESULTS: Significant differences in the preoperative knee flexion, postoperative knee flexion, preoperative knee extension, and postoperative knee extension angles, postoperative KOOS pain and activity of daily living, ß, ɤ angles were observed between the good and poor Δflexion groups. The model Chi-squared test revealed that the ɤ angle was significantly affected by the Δflexion angle. CONCLUSIONS: With the CSRP TKA, flexion insertion of the femoral component was associated with postoperative flexion ROM improvement.

Mismatch Between Residual Mitral Regurgitation and Left Atrial Pressure Predicts Prognosis After Transcatheter Edge-to-Edge Repair.

BACKGROUND: The mechanism and impact of mismatch between residual mitral regurgitation (MR) and postprocedural left atrial pressure (LAP) after transcatheter edge-to-edge repair (TEER), which may adversely affect clinical outcome, is of great interest. OBJECTIVES: This study aimed to examine the effect of hemodynamic mismatch after TEER on clinical outcomes in patients with heart failure due to severe MR and investigate the predictive factors for the mismatch using a prospective multicenter registry. METHODS: We categorized 1,477 patients into optimal (residual MR grade ≤1 and postprocedural LAP ≤15 mm Hg), mismatched (residual MR grade >1 or postprocedural LAP >15 mm Hg), and poor (residual MR grade >1 and postprocedural LAP >15 mm Hg) groups and examined their prognosis. The primary endpoint was a composite of all-cause mortality and heart failure hospitalization. RESULTS: There were 927 (62.7%), 459 (31.1%), and 91 (6.2%) patients categorized into optimal, mismatched, and poor groups, respectively. Cox regression analysis, referenced to the optimal group, revealed that the mismatched and poor groups exhibited a higher risk for the primary endpoint (HR: 1.55; 95% CI: 1.28-1.88; and HR: 1.95; 95% CI: 1.38-2.74, respectively). Six risk factors were identified as predictors of hemodynamic mismatch after TEER: body mass index, baseline left atrial volume index, atrial fibrillation, tricuspid annular plane systolic excursion value, preprocedural mean left atrial pressure, and postprocedural mean mitral valve pressure gradient. CONCLUSIONS: Post-TEER hemodynamic mismatch between residual MR and postprocedural LAP was associated with a poor prognosis. Six readily accessible perioperative parameters predict the hemodynamic mismatch. (OCEAN-Mitral registry; UMIN000023653).

Ring-closing metathesis of dialkenylcycloalkanes for the synthesis of fused bicycloalkanes and tricycloalkanes.

Ring-closing metathesis of dialkenyldisilacycloalkane using the Grubbs catalyst, followed by hydrogenation, afforded a mixture of two disilabicycloalkanes and tetrasilatricycloalkanes. This method can synthesize a diastereomer mixture of disilabicycloalkanes with one differing alkyl side chain. The observed symmetries of the NMR spectra of anti-bicycloalkanes depend significantly on the length of the side chain. The findings may contribute to the molecular design of functional bicycloalkanes based on structural transformations of the stable forms.

MgO-enhanced ß-TCP promotes osteogenesis in both in vitro and in vivo rat models.

Allogeneic bone grafts are used to treat bone defects in orthopedic surgery, but the osteogenic potential of artificial bones remains a challenge. In this study, we developed a ß-tricalcium phosphate (ß-TCP) formulation containing MgO, ZnO, SrO, and SiO2 and compared its bone-forming ability with that of ß-TCP without biological elements. We prepared ß-TCP discs with 60% porosity containing 1.0 wt% of these biological elements. ß-TCP scaffolds were loaded with bone marrow-derived mesenchymal stem cells (BMSC) from 7-week-old male rats and cultured for 2 weeks. ALP activity and mRNA expression of osteogenic markers were evaluated. In addition, scaffolds were implanted subcutaneously in rats and analyzed after 7 weeks. In vitro, the MgO group showed lower Ca concentrations and higher osteogenic marker expression compared to controls. In vivo, the MgO group showed higher ALP activity compared to controls, and RT-qPCR analysis showed significant expression of BMP2 and VEGF. Histopathology, fluorescent immunostaining, and micro-CT also showed relatively better bone formation in the MgO group. ß-TCP with MgO may enhance bone morphology in vitro and in vivo and improve the prognosis of patients with substantial and refractory bone defects.

Artificial intelligence-assisted ultrasound imaging in hemophilia: research, development, and evaluation of hemarthrosis and synovitis detection.

Background: Joint bleeding can lead to synovitis and arthropathy in people with hemophilia, reducing quality of life. Although early diagnosis is associated with improved therapeutic outcomes, diagnostic ultrasonography requires specialist experience. Artificial intelligence (AI) algorithms may support ultrasonography diagnoses. Objectives: This study will research, develop, and evaluate the diagnostic precision of an AI algorithm for detecting the presence or absence of hemarthrosis and synovitis in people with hemophilia. Methods: Elbow, knee, and ankle ultrasound images were obtained from people with hemophilia from January 2010 to March 2022. The images were used to train and test the AI models to estimate the presence/absence of hemarthrosis and synovitis. The primary endpoint was the area under the curve for the diagnostic precision to diagnose hemarthrosis and synovitis. Other endpoints were the rate of accuracy, precision, sensitivity, and specificity. Results: Out of 5649 images collected, 3435 were used for analysis. The area under the curve for hemarthrosis detection for the elbow, knee, and ankle joints was ≥0.87 and for synovitis, it was ≥0.90. The accuracy and precision for hemarthrosis detection were ≥0.74 and ≥0.67, respectively, and those for synovitis were ≥0.83 and ≥0.74, respectively. Analysis across people with hemophilia aged 10 to 60 years showed consistent results. Conclusion: AI models have the potential to aid diagnosis and enable earlier therapeutic interventions, helping people with hemophilia achieve healthy and active lives. Although AI models show potential in diagnosis, evidence is unclear on required control for abnormal findings. Long-term observation is crucial for assessing impact on joint health.

Association between postoperative fall history and toe grip strength in patients after total knee arthroplasty: A prospective observational study.

BACKGROUND: Factors associated with falls after total knee arthroplasty (TKA) have been rarely reported. The aim of this study was to identify factors that influence the incidence of falls after TKA, focusing on toe grip strength (TGS) in particular, which has been associated with falls in older adults. METHODS: 217 patients who underwent TKA were included and followed up for 1 year. Main study outcome measures were the presence or absence of falls within 1 year after TKA. Multiple logistic regression analysis was used with postoperative falls as the dependent variable and preoperative falls and postoperative TGS on the affected sides as independent variables. RESULTS: 170 (43 and 127 in the fall and non-fall groups) patients were included in the analysis. The presence of a preoperative falls history before TKA and a weak postoperative affected TGS indicated an increased susceptibility of the patient to fall postoperatively. CONCLUSIONS: Results of the current study revealed the association between postoperative TGS and postoperative falls. We highlight the importance of preoperative fall monitoring and postoperative TGS evaluation to prevent falls after TKA.

Validation of compositional MRI from a histological standpoint: Advantages of three-dimensional T1ρ mapping for quantitative evaluation of articular cartilage.

PURPOSE: We aimed to investigate the relationship between quantitative evaluation by compositional MRI, including T1ρ, and histological and macroscopic assessments, to verify the validity of compositional MRI, and examine the relationship between compositional MRI evaluation reconstructed in three dimensions (3D) and histological and visual assessments. METHOD: Twenty-seven patients with knee osteoarthritis underwent T1ρ and T2 magnetic resonance imaging (MRI). Histological and gross tissue evaluations were performed on the excised bone sections of total knee arthroplasty. Semi-quantitative histological evaluation of tissue changes were assessed by measuring the optical density of digitally captured safranin O-stained and Collagen type II antibody-stained paraffin sections. Macroscopic cartilage severity was determined on a 5-grade scale (G0-G5). T1ρ and T2 values (3D and 2D), and their correlation with each of these parameters were investigated. RESULTS: 3D T1 ρ is negatively correlated with histological evaluations and positively correlated with visual assessments. Only 3D T1ρ values correlated with histological quantitative evaluation (Safranin-O staining; r = -0.53, P = 0.014, Collagen type II antibody staining; r = -0.60, P = 0.019). 2D T1ρ and 3D, 2D T2 values did not correlate with histological evaluation results. Macroscopic cartilage severity grade correlated with all T1ρ and T2 values (3D T1ρ; r = 0.61, P < 0.001, 2D T1ρ; r = 0.52, P < 0.001, 3D T2; r = 0.33, P = 0.045, 2D T2; r = 0.41, P = 0.01). CONCLUSIONS: 3D T1ρ mapping reflects the changes in the molecular structure of the cartilage matrix that occur in arthropathic changes and may be an effective tool for detecting cartilage degeneration.

Template Synthesis of Disilacycloalkanes Utilizing the Reactivity of a Siloxane Bond.

The investigation of large and flexible macrocyclic compounds has garnered significant attention due to their functions as host molecules and linkers. Although the synthetic yields of such compounds, achieved by linking two molecular fragments, are often hindered by the flexibility of the molecular skeleton, one of the effective solutions is template synthesis for the macrocycles. In this study, a novel template synthesis for disilacycloalkanes by leveraging the reactivity of a siloxane bond was investigated. The yields obtained through the template methods surpassed those of the nontemplate approach, and the introduction of substituents to the silicon atoms was also accomplished with success. All of the resulting disilacycloalkanes crystallized exceptionally well, enabling their structural determination through X-ray crystallography. Notably, the stability of these structures was elucidated by analyzing dispersion forces between alkyl chains, using density functional theory (DFT) calculations. This template synthesis method demonstrates its efficacy in synthesizing molecular systems that encompass two functional moieties linked with macroalkanes.

Force-sensing treadmill gait analysis system can detect gait abnormalities in haemophilia patients without arthropathy.

BACKGROUND: Joint damage in patients with haemophilia (PwH) is commonly assessed by imaging, but few reports have described how structural changes in joints, for example, haemophilic arthropathy (HA)-affect gait ability. OBJECTIVES: We evaluated gait function among PwH with HA, PwH without HA, and people without haemophilia (non-PwH) using a Zebris FDM-T treadmill (FDM-T), an easy-to-use gait assessment instrument with a force sensor matrix. METHODS: The following gait parameters were collected: centre of pressure trajectory intersection (COPi) anterior/posterior variability, COPi lateral variability, COPi anterior/posterior symmetry, COPi lateral symmetry, single-limb support line (SLSL) length, and SLSL variability. Participants walked at their typical gait speed. The physical function of the PwH was assessed by the Hemophilia Joint Health Score (HJHS). Parameters were compared among the three groups. RESULTS: Twelve PwH with HA, 28 PwH without HA, and 12 non-PwH were enrolled. Gait speed significantly differed between groups (non-PwH, 3.1 ± 0.7; PwH without HA, 2.0 ± 0.7; PwH with HA; 1.5 ± 0.4). The COPi anterior/posterior variability, COPi lateral variability, SLSL length, and SLSL variability were greater in the PwH groups than in the non-PwH group. The COPi lateral symmetry differed between PwH with HA and the other groups. The HJHS was not correlated with gait parameters among PwH with HA. CONCLUSIONS: Gait parameters and speed were abnormal in both PwH with HA and PwH without HA. The FDM-T can be used to identify early stages of physical dysfunction that cannot be detected by conventional functional assessments such as the HJHS.

Optimal retractor insertion point for nerve safety during total hip arthroplasty: an anatomical study on the femoral and sciatic nerves in relation to hip motion.

BACKGROUND: Nerve injury is one of the most serious complications of total hip arthroplasty (THA). It is suspected to be a result from nerve compression or direct injury caused by an acetabular retractor. The anatomical relationship between the acetabular rim and the femoral and sciatic nerves, including hip motion, has not been investigated. This study aimed to identify the optimal position for retractor insertion during THA to prevent nerve damage. METHODS: A total of 28 hip joints from 14 freshly frozen cadavers were used. Using an anterolateral approach, each cadaver was immobilised in the lateral decubitus position and deployed to measure the distance between the nerves and the acetabular rim, while the hip joint was changed to the extension, neutral, and flexion positions. RESULTS: Three femoral nerves were closest to the anterior margin of the acetabulum at 90° and 120° of extension and farthest away at 30° of flexion. The sciatic nerve was closest to the posterior margin of the acetabulum at 90° and 120° of flexion and farthest away at 30° and 150° of extension compared with the other points. CONCLUSIONS: To prevent nerve damage during THA, we suggest that the retractor be inserted at the points where the nerves are the farthest away, such as at 30° and 150°. The femoral and sciatic nerves vary in their movements depending on the hip position. Therefore, the safe insertion of a retractor is recommended for hip flexion of the femoral nerve and extension of the sciatic nerve. Additionally, it is important to carefully insert the retractor along the acetabular margin without penetrating the joint capsule. Overall, this study provides valuable insights into the anatomical location and movement of the femoral and sciatic nerves in relation to hip motion and can help inform surgical techniques for safer THA.

Minimum-incision transsubclavian transcatheter aortic valve replacement with balloon-expandable valve for dialysis patients.

BACKGROUND: Dialysis patients undergoing transcatheter aortic valve replacement (TAVR) face increased risk and have poorer outcomes than non-dialysis patients. Moreover, TAVR in dialysis patients using an alternative approach is considered extremely risky and little is known about the outcomes. We routinely perform minimum-incision transsubclavian TAVR (MITS-TAVR), which is contraindicated for transfemoral (TF) TAVR. This study aimed to evaluate the outcomes of MITS-TAVR compared with those of TF-TAVR in dialysis patients. METHODS: This single-center, observational study included 79 consecutive dialysis patients who underwent MITS-TAVR (MITS group, n = 22) or TF-TAVR (TF group, n = 57) under regional anesthesia. RESULTS: The rates of peripheral artery disease (MITS vs. TF, 72.7 % vs. 26.3 %; p < 0.01), shaggy aortas (MITS vs. TF, 63.6 % vs. 5.26 %; p < 0.01), and tortuous aortas (MITS vs. TF, 13.6 % vs. 1.75 %; p = 0.031) were significantly higher in the MITS group. The 30-day mortality was 2.53 % and comparable between the two groups (MITS vs. TF, 4.54 % vs. 1.75 %; p = 0.479). In the MITS group, 14 patients had ipsilateral dialysis fistulas, and three patients had patent in situ ipsilateral internal thoracic artery grafts; however, no vascular complications were observed. Kaplan-Meier survival curves for the two groups showed no significant difference in the survival rate (at 2 years; MITS vs. TF, 77.3 % vs. 68.8 %; p = 0.840) and freedom from cardiovascular mortality (at 2 years; MITS vs. TF, 90.9 % vs. 96.5 %; p = 0.898). The multivariable Cox proportional hazard model also indicated that survival in the MITS group was not significantly different from that in the TF group (hazard ratio 1.48; 95 % confidence interval, 0.77-2.85, p = 0.244). The patency rate of ipsilateral dialysis fistula was 100 % during follow-up. CONCLUSION: The outcome of MITS-TAVR was comparable to that of TF-TAVR in dialysis patients, despite the higher risk of patient characteristics.

Single-facility study of the effectiveness of rehabilitation therapy using wearable hybrid assistive limb for patients with bleeding disorders: study protocol for a randomised controlled trial.

INTRODUCTION: Haemophilic arthropathy, a serious complication of haemophilia, results from recurrent joint bleeding, causing progressive joint damage and severely impacting patient quality of life. Rehabilitation therapy (RT) effectively addresses declining physical function due to joint degradation, but pain during RT can hinder its success. Therefore, an effective pain-alleviating treatment method is required. The single-joint hybrid assistive limb (HAL-SJ), a powered exoskeleton, measures bioelectric potential during muscle contraction and provides motorised support, potentially alleviating pain. OBJECTIVE: This study outlines our protocol for a randomised, prospective, single-blind (evaluator) trial aimed to investigate the effects of HAL-SJ on pain reduction during RT, kinesiophobia and other physical functions in patients with haemophilia. METHODS AND ANALYSIS: This two-group comparison intervention study will include 24 male patients aged 12-85 years diagnosed with a bleeding disorder necessitating RT for pain and physical function improvement. The primary outcome measures pain changes during the first and second RT session in patients receiving HAL-SJ-assisted RT compared with traditional RT without HAL-SJ. The secondary outcomes include kinesiophobia (Japanese version of the Tampa Scale for Kinesiophobia), standing position gait (zebris FDM-T treadmill), range of motion (manual goniometer) and body surface temperature (infrared thermography camera) during the study period of up to 3 months or until the end of 10 RTs. RT intensity remains below that required to move the affected joint against gravity, given HAL-SJ's muscular support. The follow-up period extends to 1 month after the last RT. Intergroup study variables are compared by an unpaired t-test or Mann-Whitney test. Intragroup comparisons of secondary outcomes are analysed by a paired t-test or Wilcoxon signed-rank test. ETHICS AND DISSEMINATION: This study was approved by the accreditation committee of Nara Medical University Hospital. The study results will disseminate through publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: jRCTs052220076.

Influences of comorbidities on perioperative rehabilitation in patients with gastrointestinal cancers: a retrospective study.

BACKGROUND: Older patients are more likely to have comorbidities than younger patients, and multiple comorbidities are associated with mortality in patients with cancer. Therefore, we hypothesized that a functional comorbidity index could predict the therapeutic effects of rehabilitation. OBJECTIVES: In this study, we investigate whether the comorbidities influenced the execution and therapeutic effects of rehabilitation. METHODS: A consecutive cohort of 48 patients with gastrointestinal cancer who underwent surgery between January 1 and November 30, 2020, was analyzed. Charlson Comorbidity Index (CCI) scores were calculated based on data derived from medical records. The primary outcomes were ambulation status, duration (days) from the start of postoperative rehabilitation, and length of hospital stay. We investigated the relationship between CCI scores and primary outcomes. RESULTS: The CCI did not correlate with the duration of rehabilitation or the length of hospital stay. Subsequently, patients with functional recovery problems were evaluated, and we identified the conditions that were not included in the list using CCI scores. Most conditions are associated with surgical complications. Furthermore, using the Clavien-Dindo classification (CDC), we assessed the clinical features of the severity of complications. We found that the length of stay and the duration to start rehabilitation were significantly longer in the patients with higher severity of surgical complications (CDC≧III) than in those with lower severity (CDC≦II). CONCLUSIONS: Treatment-related conditions may significantly impact the perioperative period more than the original comorbidities. In addition to original comorbidities, events related to surgical complications should be assessed to determine the therapeutic effects of rehabilitation in patients with gastrointestinal cancer.

Synthesis of Dimethyldisilabicycloalkanes: Cage-Size Effects on the Relative Stabilities between In,Out and Twist-Out,Out Forms.

In large bicycloalkanes, several in/out forms exist, wherein substituents on the bridgehead atoms are oriented either outside or inside the cage. The relative stability between the in,out and twist-out,out forms, which can interconvert through homeomorphic conversion, was found to depend upon the cage size. The in,out form demonstrated thermodynamic stability in the smaller C10 derivative, whereas the twist-out,out form prevailed in the larger derivatives of C14 and C18 plausibly as a result of dispersion forces among the chains.

[Emergent Transcatheter Aortic Valve Implantation for Degenerated Surgical Aortic Valve Under Local Anesthesia:Report of a Case].

An 89-year-old man who had undergone aortic valve replacement with a 21 mm Mosaic bioprosthetic valve at another hospital 14 years ago was admitted to the emergency room for a sudden respiratory distress two days prior and was diagnosed with severe aortic regurgitation( AR) caused by valve insufficiency and acute heart failure secondary to low cardiac function. Upon admission, he was found to have severe hypoxia with PaO2 of 40 mmHg range, and transcatheter aortic valve replacement (TAVI, TAV in SAV) with a 20 mm SAPIEN3 was performed under local anesthesia for fear of hypotension while under general anesthesia. After confirming that AR had completely disappeared, the patient was intubated and discharged from the operating room on a mechanical ventilator. The patient was weaned from the ventilator on the second postoperative day and was transferred to the other hospital for rehabilitation, 48 days postoperatively. Although there is no report on the comparative study of anesthesia methods for emergency transcatheter aortic valve implantation( TAVI), TAVI under regional anesthesia is minimally invasive with a lower risk for hypotension than general anesthesia. Therefore, we believe it is useful for patients with acute heart failure and hypotension. In addition, it is important to use a balloon expandable valve with excellent implantability to complete the procedure in a short time.

Risk factors for mortality after hip fracture surgery in Japan using the National Database of Health Insurance Claims and Specific Health Checkups of Japan.

We investigated the risk factors for mortality of hip fracture in the elderly using the National Database of Health Insurance Claims in Japan, and survival was significantly related to sex, age, fracture type, surgical procedure, delayed operative date, comorbidities, blood transfusions, and pulmonary embolism. PURPOSE: Hip fracture is the most common fracture in the elderly and is known to have a high mortality rate. In Japan, to the best of our knowledge, no studies have reported on mortality risk factors for hip fracture using nationwide registry databases. This study aimed to determine the number of occurrences of hip fracture and factors that increase mortality using the National Database of Health Insurance Claims and Specific Health Checkups of Japan. METHODS: This study included extracted data from patients who were hospitalized and underwent surgical treatment for hip fracture between 2013 and 2021, using a nationwide health insurance claims database in Japan. Patient characteristics, such as sex, age, fracture type, surgical procedure, delayed operative date, comorbidities, blood transfusions, and pulmonary embolism, were tabulated to obtain 1-year and in-hospital mortality rates. RESULTS: Both 1-year and in-patient survival were significantly lower in men, older patients, patients who underwent surgery after 3 days of admission, and patients with trochanteric and subtrochanteric fractures, internal fixation, more preoperative comorbidities, blood transfusions, and pulmonary embolism. CONCLUSIONS: Survival was significantly related to sex, age, fracture type, surgical procedure, delayed operative date, comorbidities, blood transfusions, and pulmonary embolism. As the number of male patients with hip fracture will increase with the aging of society, medical staff must provide sufficient information before surgery to avoid postoperative mortality.

Synthesis and structure of stannane-based molecular bevel gears having substituents on a tin linker.

Ditriptycylmethanes are known as molecular bevel gears because the two triptycyl groups act as wheels and display correlated rotation in solution. However, introduction of substituents on the methylene junction for chemical modification of the bevel gears has been difficult due to steric hindrance of the triptycyls. In this study, stannane-based molecular bevel gears with organic substituents on the tin linker were achieved by utilizing long Sn-C bonds. Ditriptycylstannanes with methyls or phenyls on the tin atoms were synthesized. Their structures were characterized by X-ray crystallography, and the angle of triptycyl-Sn-triptycyl in the diphenyl derivative was observed to be narrower than that of the dimethyl derivative due to steric hindrance of the phenyls. The gear rotation of these derivatives was observed by NMR spectroscopy through observations of the phase isomers of the corresponding methyltriptycyl derivatives. Gear slippage was observed in the high-temperature region, and the activation energy of the diphenyl derivative was higher than that of the dimethyl derivative. The observed relationship between gear rotation and substituents on the tin can aid in the molecular design of functional molecular bevel gears.