Factors influencing knee valgus alignment in Crowe type IV hip dysplasia after total hip arthroplasty.

BACKGROUND: Valgus deformity of the knee remains a complaint after total hip arthroplasty (THA) among some patients with Crowe type IV hip dysplasia. We aimed to identify the knee alignment in these patients before and after surgery, and to explore the factors contributing to postoperative knee valgus alignment. MATERIALS AND METHODS: We retrospectively reviewed a series of Crowe type IV patients who received THA between February 2010 and May 2019 in our hospital. The patients' medical data were collected from the hospital information system. On both preoperative and postoperative full limb length standing radiographs, the following parameters were measured: hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle, anatomical tibiofemoral angle, anatomical lateral distal femoral angle, femoral neck-shaft angle, pelvic obliquity, limb length, height and lateral distance of hip center, and femoral offset. Univariate and multivariate binary logistic regression were used to identify the factors influencing postoperative knee valgus alignment. RESULTS: A total of 64 Crowe type IV patients (87 hips) were included in the study. Overall, HKA improved from 176.54 ± 3.52° preoperatively to 179.45 ± 4.31° at the last follow-up. Those hips were subdivided into non-valgus group (≥ 177.0°, n = 65) and valgus group (< 177.0°, n = 22) according to postoperative HKA. Only postoperative mLDFA was a significant factor in the multivariate regression model. CONCLUSIONS: The postoperative mLDFA is a major factor related to knee valgus alignment after THA, which combines the preoperative anatomy and surgical reconstruction. Other factors previously published were found to have no significance. LEVEL OF EVIDENCE: III.

Core Decompression with Local Administration of Zoledronate and Enriched Bone Marrow Mononuclear Cells for Treatment of Non-Traumatic Osteonecrosis of Femoral Head.

OBJECTIVE: To investigate the efficacy and safety of core decompression (CD) with local administration of zoledronate and enriched bone marrow mononuclear cells (BMMCS) for the treatment of non-traumatic osteonecrosis of femoral head (ONFH). METHODS: A total of 17 patients (30 hips) diagnosed with stage II and III ONFH according to the 2019 revised Association for Research on Osseous Circulation (ARCO) staging criteria from 2012 to 2014 were retrospectively reviewed. The patients received the following therapy: the BMMCs and zoledronate were injected into the necrotic zone, respectively, along with CD. The mean age of the patients was 36.8 years; 14 were men and three were women. All patients included had non-traumatic ONFH and a minimum follow-up of 5 years, which ended when total hip arthroplasty (THA) was performed. Imaging modalities, including plain radiography, computed tomography (CT), and magnetic resonance imaging (MRI) were taken pre- and postoperatively. Harris hip score (HHS) was used to evaluate the functional outcomes of femoral head necrosis. Kaplan-Meier analysis was adopted to determine the probability of survivorship with THA as the end point in this series of patients. The correlation between radiological progression or THA and related risk factors were further analyzed. All complications were recorded. RESULTS: With THA as the follow-up endpoint, All patients were followed up for an average of 69.1 ± 20.5 months (range, 18-95 months). Preoperative imaging found six hips (20%) at ARCO stage II, 14 hips (46.7%) at stage IIIA, 10 hips (33.3%) at stage IIIB. Fourteen hips (46.7%) shown progression radiologically, while six hips (20%) underwent TKA among these patients with hip preservation. The cumulative survival was 80% (95% CI, 0.608-905) at 5 years with THA as the end point. HHS improved from 63.3 ± 8.7 preoperatively to 74.6 ± 20.6 postoperatively (P = 0.000). Radiological progression was found to be associated with ARCO stage, Japanese Investigation Committee (JIC) type, and corticosteroid exposure (P = 0.047; P = 0.012; P = 0.031). However, no correlation was found between conversion to THA and the known risk factors. No major complication was reported, with only four patients complaining about general weakness and muscle soreness, and all disappeared within 2-3 days. CONCLUSIONS: The novel treatment modality could relieve pain, delay the progression of collapse, which might be an effective and safe method for hip preservation of early and mid-term ONFH. However, the effect of this method may be related to ARCO stage, JIC type, and corticosteroid exposure.

Three-Dimensional Distribution of Bone-Resorption Lesions in Osteonecrosis of the Femoral Head Based on the Three-Pillar Classification.

OBJECTIVE: To investigate three-dimensional distribution of bone-resorptive lesions based on the three-pillar classification and its effect on the disease progression of osteonecrosis of the femoral head (ONFH). METHODS: A total of 194 femoral head CT images from 117 patients diagnosed with ARCO stage II and III ONFH were retrospectively reviewed from April 2014 to February 2019. Three-dimensional structures of the femoral head and the bone-resorptive lesions were reconstructed. Using the three-pillar classification and coronal plane of the femoral head, we divided each femoral head into six regions to observe the location characteristics of bone-resorption lesions, and explore the destruction of different areas of the femoral head by the bone-resorptive lesions. Then the hips were divided into two groups based on whether they contained bone-resorption lesions and compared the difference of stage II and stage III between the two groups. RESULTS: The regional distribution revealed 39 (27.27%), 55 (38.46%), six (4.20%), 23 (16.08%), 17 (11.89%) and three (2.10%) bone-resorptive lesions in regions I, II, III, IV, V and VI respectively. The lateral pillar, AL (I + IV), contained 44.76% of the lesions, central pillar, C (II + V), 48.95%, and medial pillar, M (III + VI), 6.29%. Moreover, there were 81.82% bone-resorption lesions in anterolateral pillar, AL (I + II + IV), and 18.18% in posteromedial pillar, PM (III + V + VI). In all ONFH hips, the lateral pillar of 81(88.04%) femoral heads were affected, the central pillar of 84 (91.30%) femoral heads were affected, and the medical pillar of 29 (31.52%) femoral heads were affected. The ratio of ARCO stage III in the group with bone-resorption lesions was significantly higher than that of the group without bone-resorption lesions (76.09% vs 30.39%, P < 0.001). CONCLUSIONS: This study demonstrated that the bone-resorption lesions are mainly distributed in the lateral and central pillar of the femoral head, and the two pillars of the femoral head are usually involved by bone-resorption lesions. Furthermore, the ratio of ARCO stage III in the group with bone-resorption lesions was significantly higher than that of the group without bone-resorption lesions, suggesting that the bone-resorption lesions might accelerate the progression of ONFH.

Multifunctional antiferromagnetic materials with giant piezomagnetism and noncollinear spin current.

We propose a new type of spin-valley locking (SVL), named C-paired SVL, in antiferromagnetic systems, which directly connects the spin/valley space with the real space, and hence enables both static and dynamical controls of spin and valley to realize a multifunctional antiferromagnetic material. The new emergent quantum degree of freedom in the C-paired SVL is comprised of spin-polarized valleys related by a crystal symmetry instead of the time-reversal symmetry. Thus, both spin and valley can be accessed by simply breaking the corresponding crystal symmetry. Typically, one can use a strain field to induce a large net valley polarization/magnetization and use a charge current to generate a large noncollinear spin current. We predict the realization of the C-paired SVL in monolayer V2Se2O, which indeed exhibits giant piezomagnetism and can generate a large transverse spin current. Our findings provide unprecedented opportunities to integrate various controls of spin and valley with nonvolatile information storage in a single material, which is highly desirable for versatile fundamental research and device applications.

Significance of changes in the concentration of inflammatory factors in blood or cerebrospinal fluid in evaluating the severity and prognosis of spontaneous cerebral hemorrhage: A systematic review and meta-analysis.

OBJECTIVE: Spontaneous intracerebral hemorrhage (SICH) often leads to severe disability, while inflammation plays an important role in SICH-induced secondary brain injury. The purpose of this study was to investigate the value of inflammatory factors as a means of evaluating the prognosis of SICH and to investigate the relationship between inflammatory factors and the severity and prognosis of SICH. METHODS: The articles published before November 1 2020 were searched through PubMed, EMBASE, Cochrane library and web of science. Revman5.3 was used, using the inverse variance model to pool the SMD of TNF-a and interleukin concentration. RESULTS: A total of 25 studies involving 3333 subjects were included in this paper. The concentration of TNF-α in the blood or cerebrospinal fluid of severe SICH patients was significantly higher than that of milder SICH patients or healthy population; SICH patients with high TNF-α concentration had a 1.06 times greater odds of poor outcomes than patients with low TNF-α concentration, odds ratio (OR) = 1.06[95% CI, 1.01-1.12]. The concentration of interleukin-6 (IL-6) in severe SICH patients was significantly higher than that in milder SICH patients; patients with high IL-6 concentration had a 2.61 times greater odds of poor outcomes than patients with low IL-6 concentration, OR = 2.61[95% CI, 1.79-3.80]. CONCLUSIONS: The detection of concentrations of TNF-α and IL-6 in peripheral blood may be helpful for the objective and quantitative assessment of the severity and prognosis of patients with SICH, and have certain significance for the selection of appropriate treatment options.

The progression of intracerebral hemorrhage (ICH) is related to the expression of integrin Β1 (ITGB1).

BACKGROUND: Intracerebral hemorrhage (ICH) is fatal and detrimental to quality of life. Clinically, options for monitoring are often limited, potentially missing subtle neurological changes. Integrin ß 1 (ITGB1) and ß 3 (ITGB3) are the main components of integrin family receptors, which regulate the formation and stability of blood vessels. This study explored the relationship between the expression of ITGB1 and ITGB3 in intracerebral hemorrhage (ICH) to analyze their functional and clinical relevance. METHODS: The expression of ITGB1 and ITGB3 in ICH was accomplished by immunohistochemical (IHC) staining and western blotting (WB) analysis, respectively. RESULTS: Furthermore, the results demonstrated that ITGB1 was expressed in ICH tissues, but ITGB3 was not expressed in ICH tissues. CONCLUSIONS: In summary, the clinical progression of ICH was related to the expression of ITGB1. ITGB1 may be a potential biomarker and contribute to the treatment of ICH.

The Variation of the Pelvis in Unilateral Crowe Type IV Developmental Dysplasia of the Hip.

OBJECTIVE: To investigate variation of the pelvis in unilateral Crowe type IV developmental dysplasia of the hip (DDH) and analyze the reliability of pelvic landmarks. METHODS: We retrospectively received preoperative anteroposterior pelvic radiographs for 89 adult patients with unilateral Crowe type IV DDH at our institution between September 2008 and May 2019. Forty-eight patients without a false acetabulum was type IVA and 41 with a false acetabulum was type IVB. The heights of the ilium, acetabulum, and ischium areas in affected and unaffected sides were measured. The ratios of the three areas in entire pelvis are calculated. The discrepancies of bilateral iliac crest, inferior sacroiliac articulation, teardrop, and ischial tuberosity on the bisector of the pelvis were also measured. RESULTS: The mean heights of the ilium, acetabulum, ischium areas in the affected side were 74.4, 88.6, and 37.0 mm, respectively, in type IVA group and 77.7, 83.5, and 37.8 mm, respectively, in type IVB group. The heights in the unaffected side were 82.1, 84.6, and 43.8 mm, respectively, in type IVA group and 84.6, 82.0, and 44.0 mm, respectively, in type IVB group. The ratios of the ilium, acetabulum, ischium areas in affected side of Crowe type IVA group were 0.37, 0.44, and 0.19, respectively, and the ratios in unaffected side were 0.39, 0.40, and 0.21, respectively. The ratios in affected side of Crowe type IVB group were 0.39, 0.42, and 0.19, respectively, and the ratios in unaffected side were 0.40, 0.39, and 0.21, respectively. The discrepancies of bilateral iliac crest, inferior sacroiliac articulation, teardrop, and ischial tuberosity on the line of the bisector of the pelvis in Crowe type IVA group were 5.6, 5.2, 2.0, and 7.1 mm, respectively. Those in Crowe type IVB group were 8.1, 3.5, 3.5, and 4.9 mm, respectively. CONCLUSIONS: Pelvic asymmetry was a common occurrence in unilateral Crowe type IV DDH in adults. Furthermore, it should be reliable to use teardrop as pelvic landmark to balance leg length discrepancy in preoperative planning.

Quantum spin Hall and quantum anomalous Hall states in magnetic Ti2Te2O single layer.

Magnetic topological insulators, such as MnBi2Te4have attracted great attention recently due to their application to the quantum anomalous Hall (QAH) effect. However, the magnetic quantum spin Hall (QSH) effect in two-dimensional (2D) materials has not yet been reported. Here based on first-principle calculations we find that Ti2Te2O, a van der Waals layered compound, can cherish both the QAH and QSH states, depending on the magnetic order in its single layer. If the single layer was in a chessboard antiferromagnetic (FM) state, it is a QSH insulator which carries two counterpropagating helical edge states. The spin-orbit-couplings induced bulk band gap can approach as large as 0.31 eV. On the other hand, if the monolayer becomes FM, exchange interactions would push one pair of bands away from the Fermi energy and leave only one chiral edge state remaining, which turns the compound into a Chern insulator (precisely, it is semimetallic with a topologically direct band gap). Both magnetic orders explicitly break the time reversal symmetry and split the energy bands of different spin orientations. To our knowledge, Ti2Te2O is the first compound that predicted to possess both intrinsic QSH and QAH effects. Our works provide new possibilities to reach a controllable phase transition between two topological nontrivial phases through magnetism tailoring.

Pseudotumor and repeated dislocation after total hip arthroplasty with ceramic-on-metal bearing: a case report.

Pseudotumor is a rare complication following total hip arthroplasty (THA) with ceramic-on-metal (CoM) bearings. There is still in controversy about the using of CoM bearings when conducting surgery. We reported a case of a 47-year-old woman who underwent cementless CoM bearing THA because of left Crowe type III dislocation of the hip (DDH) in December 2009. One year after THA, she presented at our hospital complaining of crunching noise, pain, and decreased level of function. A revision surgery was performed because of left hip instability in December 2010, we adjusted the excessive anteversion of stem and replaced the head by using the long-neck ceramic head. In February 2019, she was admitted to our hospital complaining of repeated dislocation and fracture of greater trochanter. During the re-revision surgery, a pseudotumor and grey synovial sac were revealed. The metal liner was replaced with a ceramic liner and the greater trochanter was reattached using the Cable-Ready system. Clinical outcome was successful at 6 months postoperatively. This case vividly demonstrated CoM bearing should be avoided in THA. The pseudotumor highly destructed the periprosthetic soft tissues and the bone, which leaded to dislocation and periprosthetic fracture. The surgeon should be aware of the complication so that prompt diagnosis and treatment can be performed.

One-Stage Total Hip Arthroplasty with Modular S-ROM Stem for Patients with Bilateral Crowe Type IV Developmental Dysplasia.

OBJECTIVE: The aim of the present paper was to evaluate the results of one-stage total hip arthroplasty (THA) for patients with bilateral Crowe type IV developmental dysplasia of the hip (DDH). METHODS: Data for 58 patients (116 hips) with bilateral Crowe type IV DDH who had one-stage THA performed by the same surgeon during the period of April 2008 to February 2019 were retrospectively reviewed. The mean age of the patients was 37.3 years; 5 were men and 53 were women. All patients underwent THA through the posterolateral approach using the Pinnacle acetabular cup, a ceramic-on-ceramic bearing, and the modular S-ROM stem. Subtrochanteric shortening osteotomy was performed on 86/116 hips. Intraoperative conditions were recorded. Radiographic and functional outcomes were evaluated, and complications were recorded. RESULTS: All patients were followed up for an average of 71.3 ± 37.6 months (range, 12-140). The mean operative time was 276.5 ± 57.9 min (range, 175-540). The mean intraoperative blood loss was 933.6 ± 400.8 mL (range, 300-2000). The mean transfusion requirement was 1778 ± 798.0 mL (range, 575-4550). The mean length of hospital stay was 8.6 ± 3.7 days (range, 5-22). At the final follow-up, no loosening of acetabular and femoral components was observed. No osteolysis and heterotopic ossification occurred. The mean Harris hip scores were improved from 55.4 ± 14.3 preoperatively to 91.3 ± 4.2 postoperatively (P < 0.001) In terms of complications, no perioperative deaths were recorded. Deep vein thrombosis occurred in 1 hip, with no pulmonary embolism. Intraoperative femur fracture occurred in 3 hips, nerve injury in 1 hip, and leg length discrepancy in 1 patient. Postoperative dislocation occurred in 5 hips and nonunion in 1 hip. CONCLUSION: Our data demonstrated that one-stage bilateral THA for bilateral Crowe type IV DDH is feasible and can effectively restore hip function.

Finite Element Assessment of the Screw and Cement Technique in Total Knee Arthroplasty.

BACKGROUND: The screw and cement technique is a convenient method used to rebuild medial tibial plateau defects in primary total knee arthroplasty (TKA). The objective of this study was to perform a finite element assessment to determine the effect of different numbers of screws on the stability of TKA and to determine whether differences exist between two different insertion angles. METHOD: Six tibial finite element models with defects filled with screws and cement and one model with defects filled only with cement were generated. Contact stresses on the surface of cancellous bone in different areas were calculated. RESULTS: Compared to the cement-only technique, the stress on the border of cancellous bone and bone cement decreased by 10% using the screw and cement technique. For bone defects with a 12% defect area and a 12-mm defect depth, the use of 1 screw achieved the greatest stability; for those with a 15% defect area and a 20-mm defect depth, 2 screws achieved the greatest stability. CONCLUSIONS: (1) The screw and cement technique is superior to the bone cement-only technique. For tibial defects in which the defect area comprises a large percentage but the depth is less than 5 mm, the screw and cement technique is recommended. (2) Vertical screws can achieve better stability than oblique screws. (3) Screws should be used in moderation for different defects; more is not always better.

Model to Predict Need for Subtrochanteric Shortening Osteotomy During Total Hip Arthroplasty for Crowe Type IV Developmental Dysplasia.

BACKGROUND Indications for subtrochanteric shortening osteotomy (SSOT) during Crowe type IV developmental dysplasia of the hip (DDH) are unclear. The aim of this retrospective study was to create a model to predict the need for performing SSOT. MATERIAL AND METHODS One hundred forty-nine patients (186 hips) with Crowe Type IV DDH who underwent total hip arthroplasty (THA) with S-ROM implants from January 2010 to November 2018 were included in the study. The acetabular components were placed at the true acetabulum and the trial femoral component was inserted. Reduction then was attempted and if it could not be achieved, SSOT was performed. Using multivariable Cox regression analysis, a model was constructed that included age, sex, surgical history, use of a cone- or triangle-shaped sleeve, secondary acetabulum formation, and percentage of dislocation as predictive factors for SSOT. RESULTS SSOTs were performed on 140 of 186 hips. Secondary acetabulum formation was present in 27 hips (58.70%) in which SSOT was not performed 7 (5.00%) in which it was performed. Cone-shaped sleeves were used in 17 hips (36.96%) in which SSOT was not performed versus 15 (10.71%) hips in which it was performed. Dislocation occurred in 31.30±5.80% hips in which SSOT was performed versus 24.05±4.39% of those in which it was not performed. Percentage of dislocation was associated with an increased likelihood of SSOT (odds ratio [OR] 1.24, 95% confidence interval 1.11-1.38), whereas secondary acetabulum formation (OR 0.10, 0.03-0.33) and use of a cone-shaped sleeve (0.18, 0.06-0.53) were associated with decreased likelihood of SSOT. We established a model for prediction of SSOT with a nanogram and the discriminative ability (C statistic) of it was 0.918 (0.79-0.92). CONCLUSIONS Factors that significantly affect likelihood of performing an SSOT were identified and a model with significant ability to predict the need for SSOT in patients with Crowe Type IV DDH was created.

Therapeutic effect and side effects of Bevacizumab combined with Irinotecan in the treatment of paediatric intracranial tumours: Meta-analysis and Systematic Review.

WHAT IS KNOWN AND OBJECTIVE: Bevacizumab (BVZ) is an angiogenesis inhibitor that often works well with chemotherapeutic drugs for the treatment of solid intracranial tumours in children. This meta-analysis discusses the efficacy and side effects of BVZ combined with irinotecan in the treatment of patients (younger than 21 years of age) with recurrent, progressive or refractory intracranial tumours. METHODS: We searched for articles published before 31 October 2018 in PubMed, EMBASE, Cochrane library and Web of Science. We selected relevant literature on the combination of BVZ and irinotecan in the treatment of children with intracranial tumours. Objective response was evaluated by combining partial response (PR), complete response (CR), stable disease (SD) and progressive disease (PD), and survival time was evaluated by combining overall survival (OS) and progression-free survival (PFS); common side effects were also analysed. All data included were obtained from single-arm data, with no control groups. RESULTS AND DISCUSSION: A total of 13 studies involving 272 patients were included. We found that out of 41% patients who showed an objective response following the BVZ therapy combined with irinotecan, 28% achieved a PR, 13% achieved a CR, 32% showed a SD, and 43% had a PD; PFS and OS were 6.47 and 11.9 months, respectively; gastrointestinal dysfunction, leukopenia and hypertension were the three most common adverse events, accounting for 36.7%, 33.6% and 22.1%, respectively, whereas musculoskeletal disorders had the lowest occurrence, accounting for 3.9%. WHAT IS NEW AND CONCLUSION: BVZ combined with irinotecan-based chemotherapy had a better response and prolonged survival in the treatment of paediatric intracranial tumours than radiation therapy or chemotherapy. Gastrointestinal dysfunction, leukopenia and hypertension were the toxic side effects with the highest incidence.

Reverse reaming distraction for acetabular reconstruction of chronic pelvic discontinuity.

BACKGROUND: The acetabular distraction technique demonstrates encouraging radiographic and clinical outcomes in treating chronic pelvic discontinuity. The aim of this study is to describe a modified distraction technique and to show our results. METHODS: This study identified 12 cases of chronic pelvic discontinuity undergoing primary or revision total hip arthroplasty (THA) with the technique of reverse reaming distraction between July 2015 and November 2018. All 12 patients had a minimum follow-up of 12 months. Radiographs were reviewed to inspect for component loosening. Clinical assessment included the Harris hip score (HHS) and an ambulatory scoring system. RESULTS: At the time of final follow-up, no patient was revised. One patient had up to 1 cm migration of the cup in a horizontal or vertical direction and more than 20° change in the abduction angle but was asymptomatic. In the remaining 11 patients, no migration of the component was detected. Both the HHS and ambulatory score showed improvement in all patients. There were no perioperative complications. No postoperative dislocation occurred. CONCLUSIONS: Reverse reaming distraction is a feasible technique in treatment of chronic pelvic discontinuity, with encouraging results at early term. However, ongoing follow-up is required to determine the long-term prognosis in patients receiving this technique.

Three-dimensional distribution of cystic lesions in osteonecrosis of the femoral head.

PURPOSE: The aim of this study was to investigate the location characteristics of cystic lesions in a three-dimensional context and discuss the mechanism of formation. METHODS: A total of 155 femoral head computed tomography images from 94 patients diagnosed with stage II and III osteonecrosis of the femoral head were retrospectively reviewed. Three-dimensional structures of the femoral head including the cystic lesions and necrotic area were reconstructed. We divided each femoral head into eight regions to observe the positional relationship of the cystic lesions, normal areas, and necrotic areas. RESULTS: The regional distribution revealed 14 (13%), 35 (32%), 9 (8%), 25 (23%), 6 (6%), 15 (14%), 4 (4%), and 0 (0%) cystic lesions in regions Ⅰ, Ⅱ, Ⅲ, Ⅳ, Ⅴ, Ⅵ, Ⅶ, and Ⅷ, respectively. The anteromedial zone, A (Ⅰ â€‹+ â€‹â…¢), contained 22% of the lesions, anterolateral zone, B (Ⅱ â€‹+ â€‹â…£), contained 54%, posteromedial zone, C (Ⅴ +Ⅶ), contained 9% of the lesions, and posterolateral zone, D (Ⅵ â€‹+ â€‹â…§), contained 15% of the lesions. Most of the cystic lesions (78%) were located between the normal and necrotic areas; 18% of cystic lesions were in the necrotic area â€‹and 4% were in the normal area. CONCLUSIONS: Cystic lesions most often occur at the junction of the necrotic â€‹and normal areas and are most commonly located in the anterolateral femoral head, which is similar to the distribution of the stress concentration region. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: The study showed the location characteristics of cystic lesions in osteonecrosis of femoral head, which suggested that the formation of cystic lesions may be related to stress and could accelerate the collapse of femoral head. The results can support further research on cystic lesions and provide a reference for doctors' treatment strategies for patients with osteonecrosis of femoral head.

Leg Length Balance in Total Hip Arthroplasty for Patients with Unilateral Crowe Type IV Developmental Dysplasia of the Hip.

OBJECTIVE: To explore the leg length balance in total hip arthroplasty (THA) with shortening subtrochanteric osteotomy (SSTO) or not for unilateral Crowe type IV developmental dysplasia of the hip (DDH) through the evaluation of postoperative full-length anteroposterior radiographs. METHODS: The postoperative radiographs of 60 patients with unilateral Crowe type IV DDH from July 2012 to May 2019 were retrospectively reviewed. All patients underwent THA using the Pinnacle Acetabular Cup system, a ceramic liner and femoral head, and the S-ROM stem with a proximal sleeve or cone. Patients with leg length discrepancy (LLD) < 10 mm were defined as the non-LLD group. To identify differences associated with SSTO, the group was further divided into two groups based on whether the patient underwent SSTO. A total of 48 patients (26 for SSTO and 22 for non-SSTO) were in the non-LLD group. There were 3 male and 45 female patients. The mean age of the patients in the non-LLD group was 39 years. These data, including leg length, femoral length, the height of center of rotation (COR) of the hip, the depth of the sleeve or cone in the femoral medullary canal and the height of the greater trochanter, were measured. RESULTS: In the non-LLD group, the femoral lengths in both SSTO and non-SSTO groups were significantly shorter on the operated side compared with the contralateral side, and the mean discrepancy in the SSTO group was approximately equal to the mean length of the SSTO. The mean height of the COR of the hip on the operated sides in both SSTO and non-SSTO groups was 13.2 mm, and the contralateral sides were 15.2 and 15.5 mm, respectively. The depth of the sleeve or cone in the femoral medullary canal between SSTO and non-SSTO groups was 21.7 and 30.6 mm, respectively. The depth of the sleeve or cone in the SSTO group was negatively correlated with the length of SSTO. The heights of the greater trochanter in the operated and contralateral sides were 5.3 and 16.6 mm in the SSTO group, and 13.2 and 17.2 mm in the non-SSTO group, respectively. CONCLUSIONS: Shortening subtrochanteric osteotomy led to femoral shortening on the operated side for patients with unilateral Crowe type IV DDH. The position of the sleeve or cone should be close to the apex of the greater trochanter to compensate the length of the SSTO. The position of the sleeve or cone without SSTO should be adjusted to make sure that the height of the greater trochanter on the operated side is close to that on the contralateral side.

[Effect of ceramic on ceramic total hip arthroplasty in Crowe IV developmental dysplasia of the hip].

OBJECTIVE: To observe the clinical effect of ceramic on ceramic total hip arthroplasty(THA)in Crowe IV developmental dysplasia of the hip(DDH). METHODS: From April 2008 to December 2015, 137 hips of 111 Crowe IV DDH patients received THA using Forte or Delta ceramic on ceramic by one senior surgeon, which consists of 85 unilateral hips and 26 bilateral hips. The average age of the patients was(38.88±10.83) years old ranging from 18 to 68 years old. The mean follow-up was(41.16±21.50) months ranging from 12 to 96 months. All the patients were evaluated by Harris Hip Score. Radiographic evaluations were made preoperatively and during follow-up. Harris scores, the incidence of complications such as ceramic fracture, squeaking, dislocation were observed. RESULTS: The mean preoperative Harris score was 56.54±15.67, the mean postoperative Harris score was 88.30±6.86(P=0.017). Periprosthetic osteolysis was not deteced around any cup. No ceramic fracture occurred. There were 3 cases of revision surgery due to infection, losening of the stem and limb length discrepancy, respectively; 3 cases of dislocation occurred. Seventy-seven patients were recorded the gait and the hip mobility, the hip flexion of 69 patients were above 120 degrees. CONCLUSIONS: Ceramic on ceramic bearing showed an encouraging result in Crowe IV DDH total hip arthroplasty.

Coexistence of Topological Edge State and Superconductivity in Bismuth Ultrathin Film.

Ultrathin freestanding bismuth film is theoretically predicted to be one kind of two-dimensional topological insulators. Experimentally, the topological nature of bismuth strongly depends on the situations of the Bi films. Film thickness and interaction with the substrate often change the topological properties of Bi films. Using angle-resolved photoemission spectroscopy, scanning tunneling microscopy or spectroscopy and first-principle calculation, the properties of Bi(111) ultrathin film grown on the NbSe2 superconducting substrate have been studied. We find the band structures of the ultrathin film is quasi-freestanding, and one-dimensional edge state exists on Bi(111) film as thin as three bilayers. Superconductivity is also detected on different layers of the film and the pairing potential exhibits an exponential decay with the layer thicknesses. Thus, the topological edge state can coexist with superconductivity, which makes the system a promising platform for exploring Majorana Fermions.

[Mechanical complications with self-made, antibiotic-loaded cement articulating spacers in the treatment of the infected hip replacement].

OBJECTIVE: To study the complications and efficacy of self-made, antibiotic-loaded cement articulating spacers in the treatment of the infected hip replacement. METHODS: Between January 2006 and July 2016, 265 patients (266 hips) received a self-made, antibiotic-loaded cement articulating spacer as part of a two-stage protocol. Among those patients, there were 143 males(144 hips) and 122 females(122 hips). The cement articulating spacers with vancomycin and two Steinman pins were made by a self-made mold system. Meanwhile, another antibiotic was added to the spacers according to the drug sensitivity test. Record if the infected prosthesis was removed, related complication with spacer(breakage and dislocation), Harris score, and control rate of infection. RESULTS: The mean age of two-stage revision operation was(57.4±14.2) years. Thirty-nine patients(14.7%) used extended trochanteric osteotomy(ETO) to remove the infected prosthesis. And 38 patients occurred mentioned complications(14.3%). Spacer breakage occurred in 28 cases(10.5%) and dislocation occurred in 10 cases(3.8%). The mean follow-up time was(83.4±14.6) months. The Harris hip score was from 47.56±14.23 preoperatively to 86.43±12.84 at final follow-up(P<0.05). The infection of 256 cases(96.6%) got control after revision operation. However, during postoperative follow-up, 4 cases occurred re-infection, and they were reoperated, and the infections obtained effective control after the operation. Thus total infection control rate was 95.1%(252/265). CONCLUSIONS: Antibiotic-loaded cement articulating spacer made by a self-made mold system is effective in controling infection caused by hip replacement. Related complication is less with spacer by a mould enclosing two Steinman pins. Using metallic internal fixation or allograft bone combined with spacer does not affect infection control.

[Clinical results in early and mid term of using the S-ROM femoral stem in revision].

OBJECTIVE: To investigate and the clinical effect of S-ROM modular stem in femur reconstruction in hip revision arthroplasty. METHODS: From January 2008 to January 2016, 21 patients received revision hip arthroplasties using S-ROM stems. There were 5 males and 16 females with an average of 48.33 years old(range, 29 to 73 years old). There were 13 cases caused by aseptic loosening, 4 cases by infection, 2 cases by nonunion of sub-tuberosity osteotomy, 1 case for repeated dislocation, 1 case for traumatic great trochanter fracture. Primary THA reasons:12 cases for DDH(9 cases for Crowe IV), 5 cases for femoral neck fracture, 2 cases for necrosis of femoral head, 2 cases for proximal femoral deformity caused by early infection. The femur bone defects included Paprosky II in 11 cases, IIIa in 9, and IIIb in 1. Harris hip score , pain score and hip flexion were recorded before and after operation. The subjective satisfaction was recorded at the last follow-up. RESULTS: The operation time and blood loss were 189 min(125 to 290 min) and 867 ml (200 to 2 000 ml). At the final followup, the pain score improved from (17.14±9.56) points preoperatively to (41.71±2.03) points (t=11.42, P=0.00). The function score improved from (24.01±11.02) points preoperatively to (49.95±5.38) points (t=9.73, P=0.00). Harris hip score improved from (41.15±14.81) points preoperatively to(91.67±5.83) points(t=15.33, P=0.00). The degree of hip flexion increased from (93.10±27.27) points preoperatively to (121.90±16.62) points at the last follow-up (t=4.59, P=0.00). The mean subjective satisfaction was 9.48(10 points system), 14 of which were completely satisfactory. The last follow-up hip X-ray showed 21 cases of bone ingrowth, and other femoral stem without loosening or sinking sign significantly. There were 5 cases with bone anchor syndrome around proximal femoral cuff. There were 5 cases of proximal femur fracture, 3 cases of lesser trochanter fracture, 2 cases of greater trochanter fracture intra-operatively. Due to femoral canal stenosis, there were 4 cases of pre-tied wire at lesser trochanter to prevent fractures. There was 1 case of traumatic femoral fracture around stems with a distal oblique fracture, open reduction and locking plate fixation was performed. Other patients had no nerve stretch injury, dislocation, infection and lower limb deep vein thrombosis and other complications at the final follow-up. CONCLUSIONS: S-ROM prosthesis has satisfactory results in hip revision arthroplasty with Paprosky II and III femoral defects. Especially for patients with Crowe IV DDH and other proximal femoral deformities, it is possible to adapt to the medullary cavity morphology. Excellent initial stability, less complications and long-term biological fixation can be achieved with S-ROM in femur revision.