A series of Zn(S 2 P(OR) 2 ) 2 , R ~iPr and Cy, adducts with bridging bipyridine ligands, i.e. 4,4'-bipyridine, trans-1,2-bis(4-pyridyl)ethylene and 1,2-bis(4-pyridyl)ethane have been investigated. The topology of the polymeric structures, i.e. zig-zag versus straight chain, can be controlled by the nature of the bridging bipyridine ligand in the case of adducts formed by Zn(S 2 P(OCy) 2 ) 2 , an effect that can be traced to the steric bulk of the cyclohexyl groups. Polymer formation is precluded in the case of the adduct formed between Zn(S 2 P(OCy) 2 ) 2 and 4,4'bipyridine, again a result that is directly ascribed to the steric bulk of the thiolate residue.

The femoral neck-preserving ratio is crucial in arthroplasty with a collum femoris-preserving (CFP) stem. The aim of our study was to analyze the relationships between the neck-preserving ratio and the short-term radiologic and clinical outcomes of patients who underwent total-hip arthroplasty (THA) with a CFP stem.The data of 325 hips from January 2015 to December 2016 were retrospectively reviewed. The demographic and radiologic data before and after surgery were obtained from patients. The neck-preserving ratio was defined as the ratio of the preserved femoral neck length to the preoperative femoral neck length. Correlations between the neck-preserving ratio and the radiologic and clinical outcomes of patients were analyzed.The mean neck-preserving ratio was 66.38 ± 6.91% in the current study. We divided patients into 3 groups according to the neck-preserving ratio: group A (neck-preserving ratio ≤60.00%), group B (60.00% < neck-preserving ratio < 70.00%), group C (neck-preserving ratio ≥70.00%). Radiologic features, including the neck-shaft angle ratio (0.96 ± 0.05), canal fill ratio (0.64 ± 0.07), anterior-posterior offset ratio (1.04 ± 0.10), and lateral offset ratio (2.55 ± 1.56) (ratios of the postoperative values to the preoperative values), and the prevalence of complications was significantly different among the groups (χ2 = 21.173, P < .001). In the correlation analysis, we found a moderate negative correlation between the neck-preserving ratio and neck-shaft angle ratio (r = −0.308, P < .001) and a slight positive correlation of the neck-preserving ratio with the anterior-posterior offset ratio (r = 0.415, P < .001) and the lateral offset ratio (r = 0.164, P = .003). In the linear regression analyses, the neck-preserving ratio was significantly linearly correlated with the neck-shaft angle ratio (B = −0.232, 95% confidence interval [CI] = −0.311 to −0.154, P < .001), anterior-posterior offset ratio (B = 0.589, 95% CI = 0.447–0.730, P < .001), and lateral offset ratio (B = 3.693, 95% CI = 1.256–6.131, P = .003). However, there was no significant linear correlation between the neck-preserving ratio and the canal fill ratio (B = 0.073, 95% CI = −0.033 to 0.180, P = .174). Logistic regression analyses also showed that a sufficient neck-preserving ratio was a protective factor for periprosthetic femoral fractures (odds ratio [OR] = 0.924, 95% CI = 0.859–0.994, P = .035), dislocations (OR = 0.892, 95% CI = 0.796–0.999, P = .048), and thigh pain (OR = 0.886, 95% CI = 0.818–0.960, P = .003).For CFP stems, an insufficient neck-preserving ratio is significantly correlated with poor radiologic and clinical outcomes. Therefore, surgeons should be cognizant to preserve a sufficient femoral neck length during surgery to improve the outcomes for patients undergoing THA with CFP stems.

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Objective We performed a retrospective study to compare the accuracy of preoperative planning using three-dimensional AI-HIP software and traditional two-dimensional manual templating to predict the size and position of prostheses. The purpose of this study was to evaluate the accuracy of AI-HIP in preoperative planning for primary total hip arthroplasty. Methods In total, 316 hips treated from April 2019 to June 2020 were retrospectively reviewed. A typical preoperative planning process for patients was implemented to compare the accuracy of the two preoperative planning methods with respect to prosthetic size and position. Intraclass correlation coefficients (ICCs) were used to evaluate the homogeneity between the actual prosthetic size and position and the preoperative planning method. Results When AI-HIP software and manual templating were used for preoperative planning, the stem agreement was 87.7% and 58.9%, respectively, and the cup agreement was 94.0% and 65.2%, respectively. The results showed that when AI-HIP software was used, an extremely high level of consistency (ICC > 0.95) was achieved for the femoral stem size, cup size, and femoral osteotomy level (ICC = 0.972, 0.962, and 0.961, respectively). Conclusion AI-HIP software showed excellent reliability for predicting the component size and implant position in primary total hip arthroplasty.

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Error-free mitosis depends on accurate chromosome attachment to spindle microtubules, which is monitored by the spindle assembly checkpoint (SAC) signaling. As an upstream factor of SAC, the precise and dynamic kinetochore localization of Mps1 kinase is critical for initiating and silencing SAC signaling. However, the underlying molecular mechanism remains elusive. Here, we demonstrated that the multisite interactions between Mps1 and Ndc80 complex (Ndc80C) govern Mps1 kinetochore targeting. Importantly, we identified direct interaction between Mps1 tetratricopeptide repeat domain and Ndc80C. We further identified that Mps1 C-terminal fragment, which contains the protein kinase domain and C-tail, enhances Mps1 kinetochore localization. Mechanistically, Mps1 C-terminal fragment mediates its dimerization. Perturbation of C-tail attenuates the kinetochore targeting and activity of Mps1, leading to aberrant mitosis due to compromised SAC function. Taken together, our study highlights the importance of Mps1 dimerization and multisite interactions with Ndc80C in enabling responsive SAC signaling.

Background Acetabular fracture and concomitant ipsilateral intertrochanteric femur fracture has been suggested as an unusual traumatic presentation and rarely reported in the literature. The aims of this study were (1) to identify the etiological characteristics, (2) to summarize the treatment strategy, and (3) to present the mid- to long-term results of patients with this rare traumatic presentation. Methods In this retrospective study, 18 patients (15 males, 3 females; mean age = 42.77 ± 17.74 years, range = 16 to 87 years) who were diagnosed and treated for simultaneous acetabular fracture and ipsilateral intertrochanteric fracture were included. Injury mechanisms, fracture classifications, and treatment strategies were noted. To assess functional status, the Harris score was used. To evaluate pain intensity, visual analogous scale (VAS) was used. The reduction quality of acetabular fractures was examined as per Matta’s standard. Postoperative complications were also recorded. Results The mean follow-up was 10.04 ± 3.38 (range = 6.2 to 16 years). The most common injury mechanism was traffic accident, followed by falling from a tall height. As per the Evans classification, intertrochanteric fractures were defined as type 3 in 13 patients, type 2 in one patient, and type 4 in 4 patients. In acetabular fracture site, the most common fractures were posterior wall fractures, followed by anterior column fractures. All patients received internal fixation for their intertrochanteric fractures. Ten out of 18 patients also received internal fixation for their acetabular fracture. However, for the remaining patients, acetabular fractures were treated conservatively or with fracture fragment resection. Bony healing was achieved in all but one patient who died postoperatively. Twelve patients achieved excellent and good results (Harris score ≥ 80 points) whereas five patients achieved fair and poor results (Harris score < 80 points). The proportion of patients who achieved an excellent-good Harris score was 70.6%. Dislocation of the hip was found to be an independent risk factor (HR = 9.194, 95% CI = 1.024-82.515) for the poor patient outcome. Conclusion To sum up, high-impact trauma is the main cause of acetabular fracture and concomitant ipsilateral intertrochanteric femur fracture. For patients who have undergone surgical treatment, fracture healing is usually achieved. However, the occurrence of complications, especially avascular necrosis, is the major cause of a poor prognosis. Dislocation of the hip joint at the time of injury is considered to be an important risk factor for a poor prognosis.

Background The direct anterior approach (DAA) and posterior approach (PA) are two of the most common surgical approaches used for total hip arthroplasty (THA) worldwide. The curved anatomical collum femoris-preserving (CFP) stem was designed to preserve the bone of the femoral neck and allow physiologic load transfer along the trabecular systems, which may better restore hip biomechanics, improve triplanar stem stability and improve the long-term survival rate. We believe this study will demonstrate whether the DAA is suitable for THA with CFP stems. Methods The data of patients who underwent primary THA with CFP stems from January 2010 to December 2015 were retrospectively analysed. These patients were divided into two groups (group A, DAA; group B, PA). The approach was selected by the surgeon. The demographic characteristics, preoperative diagnoses, preoperative Harris hip score, preoperative range of motion, postoperative complications, and radiologic measurements (neck-shaft angle, coronal alignment, sagittal alignment, stress shielding, anteversion, neck-preserving ratio, acetabular anteversion, acetabular inclination angle, acetabular depth, anterior-posterior offset, lateral offset, difference in leg length) were recorded for all patients. Results In this study, a total of 248 patients (185 male and 63 female) were included. No significant differences were found between group A and group B in terms of general patient information and radiologic measurements. However, the rate of nerve injury in group A (7/5.5%) was significantly higher than that in group B (1/0.8%) (p = 0.037). At 1 month after surgery, we found a significant difference between the two groups in the Harris hip score (HHS) (71.03 ± 8.04 in group A, 68.39 ± 8.37 in group B, P = 0.014) and forgotten joint score (FJS-12) (50.78 ± 7.57 in group A, 47.68 ± 7.34 in group B, P = 0.001). At 1 year after surgery, the mean FJS-12 score in group A (68.78 ± 7.54) was higher than that in group B (58.84 ± 8.91) (P < 0.001). At 5 years after surgery, the mean FJS-12 score in group A (73.38 ± 7.21) was higher than that in group B (67.16 ± 9.12) (P < 0.001). Post hoc analysis of the 1-month, 1-year, and 5-year postoperative FJS-12 scores using multiple linear regression analysis revealed that an excellent HHS led to good patient satisfaction at each time point. Conclusion In summary, unlike a “standard” femoral stem, whose alignment might be affected by the surgical approach, alignment of the CFP stem is independent from the surgical approach. Even though the DAA had a higher nerve injury rate, nerve injury from the DAA did not typically cause severe dysfunction of the lower extremity. Therefore, decisions regarding the surgical approach for patients undergoing THA with CFP stems can be made primarily based on the preference of the surgeon.