The remnant axial cortical length of the proximal femur in pertrochanteric fractures: a three-dimensional computed tomography study and its clinical implications.

BACKGROUND: Cortical buttress are important factors for postoperative stable reconstruction of per/inter-trochanteric fractures. The study aimed to measure the remnant axial cortical length (RACL) of the proximal circumference of the femur, and to determine which part of the RACL can be used reliably to postoperatively sustain the head-neck fragment as a cortical support pattern. METHODS: Eighty patients with trochanteric hip fractures admitted from January 2015 to January 2016 were included in a retrospective study. Their pre-operative computed tomography (CT) images were used to form 3D-CT reconstructions via Mimics software. After simulated rotation and movement for fracture reduction, the RACL, its three component parts-namely, the remnant anterior cortex (RAC), remnant lateral cortex (RLC), and remnant posterior cortex (RPC) -the γ angle between the anterior and posterior cortex, and the Hsu's lateral wall thickness (LWT) were evaluated. RESULTS: Patients with an A1 fracture (21/80) had a longer RACL (88.8 ± 15.8 mm) than those with an A2 fracture (60.0 ± 11.9 mm; P < 0.01). The RAC, RLC, and RPC of the RACL in A1 fractures were also significantly longer than those in A2 fractures (P < 0.001). However, the most significant difference among the three components of the RACL was in the RPC, which was 27.3 ± 7.8 mm in A1 fractures and 9.2 ± 6.6 mm in A2 fractures. In addition, the coefficient of variation of the RAC was only 20.0%, while that of the RPC was 75.5%. The average γ angle in A1 fractures was 16.2 ± 13.1°, which was significantly smaller than that in A2 fractures, which was 40.3 ± 14.5° (P < 0.001). There was a significant statistical difference in the LWT between A1 and A2 fractures (P < 0.001). There were significant differences in the RACL, RAC, RLC, RPC, γ angle, and LWT among the five subtypes (P < 0.001). CONCLUSIONS: The RAC is relatively stable in pertrochanteric fractures. Fracture reduction through a RAC buttress may help to enhance the postoperative stable reconstruction of per/inter-trochanteric fractures and make possible good mechanical support for fracture healing.

Insufficient proximal medullary filling of cephalomedullary nails in intertrochanteric femur fractures predicts excessive postoperative sliding: a case-control study.

OBJECTIVE: Excessive postoperative sliding is a common complication of intramedullary nails in the treatment of intertrochanteric femur fractures. The aim of this study was to identify risk factors for excessive postoperative sliding in the intertrochanteric fractures treated with an intramedullary nail. METHODS: A retrospective analysis of 369 patients with femoral intertrochanteric fractures treated with short intramedullary nails between February 2017 and September 2020 was performed. Patients were classified into an excessive sliding group (ES group) and a control group according to the sliding distance after 6 months of follow-up. The proximal medullary filling degree (MFD), fracture reduction patterns in the anteroposterior (AP) view and lateral view, and tip-apex distance (TAD) were evaluated and compared in each group. RESULTS: Thirty-three cases were included in the ES group, and 336 cases were included in the control group. No significant differences in age, sex, fracture side, AO Foundation and Orthopaedic Trauma Association (AO/OTA) classification, Dorr classification, Singh Osteoporosis Index (SOI), American Society of Anesthesiologists classification (ASA), TAD or fracture reduction patterns in the AP view were noted between the two groups. The negative reduction pattern can strongly predict excessive postoperative sliding (OR 4.286, 95% CI 1.637-11.216, P = 0.003). The incidence of excessive postoperative sliding increased by 8.713-fold when the MFD decreased by 10% (OR 8.713, 95% CI 1.925-39.437, P = 0.005). CONCLUSIONS: A low medullary filling degree and negative fracture reduction pattern in the lateral view were both independent risk factors for excessive postoperative sliding.

Residual lateral wall width predicts a high risk of mechanical complications in cephalomedullary nail fixation of intertrochanteric fractures: a retrospective cohort study with propensity score matching.

PURPOSE: The purpose of this study is to determine whether the integrity of the entry portal of head-neck implant is related to postoperative mechanical complications. METHODS: We retrospectively reviewed consecutive patients with pertrochanteric fractures in our hospital treated from January 1, 2018, to September 1, 2021. Based on the integrity of the entry portal for head-neck implants on the femoral lateral wall, patients were divided into two groups, including the ruptured entry portal (REP) group and the intact entry portal (IEP) group. After 4:1 propensity score-matched analyses were used to balance the baseline of the two groups, a total of 55 patients were extracted from the original participants, including 11 patients in the REP group and 44 matched patients in the IEP group. The anterior to posterior cortex width on the mid-level of the lesser trochanter was measured and defined as the residual lateral wall width (RLWW). RESULTS: Compared with the IEP group, the REP group was correlated with postoperative mechanical complications (OR = 12.00, 95% CI 1.837-78.369, P = 0.002) and hip-thigh pain (OR = 26.67, 95% CI 4.98-142.86). RLWW ≤ 18.55 mm indicated a high likelihood (tau-y = 0.583, P = 0.000) of becoming the REP type postoperatively and being more likely to suffer from mechanical complications (OR = 30.67, 95% CI 3.91-240.70, P = 0.000) and hip-thigh pain (OR = 14.64, 95% CI 2.36-90.85, P = 0.001). CONCLUSION: Rupture of entry portal is a high-risk factor for mechanical complications in intertrochanteric fractures. RLWW ≤ 18.55 mm is a reliable predictor of the postoperative REP type.

Monitoring Bevacizumab-Induced Tumor Vascular Normalization by Intravoxel Incoherent Motion Diffusion-Weighted MRI.

BACKGROUND: Accurate monitoring of tumor blood vessel normalization progression is beneficial to accurate treatment of patients. At present, there is a lack of safe and noninvasive monitoring methods. PURPOSE: To serial monitor the vascular normalization time window of tumor antiangiogenesis treatment through intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and histopathological methods. STUDY TYPE: Exploratory animal study. POPULATION: Sixty rat C6 glioma models were randomly and equally divided into the control groups (N = 30) and bevacizumab treatment groups (N = 30). Twenty-five for magnetic resonance imaging (MRI) and five for electron microscope testing in each group. FIELD STRENGTH/SEQUENCE: T1-weighted imaging (T1WI), T2WI with a fast spin echo sequence and IVIM-DWI with a spin-echo echo-planar imaging sequence at 3 T. ASSESSMENT: IVIM-DWI quantitative parameters (f, D, D*, and fD*) were obtained on days 0, 2, 4, 6, and 8 after bevacizumab treatment. After MRI, the microvessel density (MVD), pericyte coverage, and hypoxia-inducible factor-1α (HIF-1α) were assessed. Electron microscope observation was performed at each time point. STATISTICAL TESTS: One-way analysis of variance and Student's t-tests were used to compare differences within and between groups. Spearman's correlation coefficient (r) assess the correlation between IVIM and pathological parameters. The intragroup correlation coefficient was determined to assess the repeatability of each IVIM parameter. RESULTS: The IVIM-DWI perfusion parameters (f and fD*) of the treated group were higher than the control group on days 2 and 4. Compared to the control group, MVD decreased on days 2 and pericyte coverage increased on days 4 in the treatment group. Electron microscopy showed that the tight junctions of the treatment group were prolonged on days 2-4. In the control group, f had the highest correlation with MVD (r = 0.689). In the treated group, f had a good correlation with pericyte coverage (r = 0.557), HIF-1α had a moderately positive correlation with f (r = 0.480) and fD*(r = 0.447). DATA CONCLUSION: The vascular normalization time window of bevacizumab treatment of glioma was days 2-4 after antiangiogenesis treatment, which could be monitored noninvasively by IVIM-DWI. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 3.

Calcar fracture gapping: a reliable predictor of anteromedial cortical support failure after cephalomedullary nailing for pertrochanteric femur fractures.

BACKGROUND: Maintaining anteromedial cortical support is essential for controlling sliding and decreasing postoperative implant-related complications. However, adequate fracture reduction with cortical support in immediate postoperative fluoroscopy is not invariable in postoperative follow-ups. This study was conducted to investigate the risk factors leading to anteromedial cortical support failure in follow up for pertrochanteric femur fractures treated with cephalomedullary nails. METHODS: This retrospective study enrolled 159 patients with pertrochanteric fractures (AO/OTA- 31A1 and 31A2) that fixed with cephalomedullary nails. All patients were evaluated as adequate fracture reduction in immediate postoperative fluoroscopy before leaving the operation theater. The patients were separated into two groups based on the condition of the anteromedial cortex in the postoperative 3D CT with full-range observation: those with calcar support maintained in Group 1 and those with calcar support lost in Group 2. Demographic information, fracture classification, TAD (tip-apex distance), Cal-TAD, Parker ratio, NSA (neck-shaft angle), reduction quality score, and calcar fracture gapping were collected and compared. Logistic regression analysis was conducted to explore the risk factors leading to anteromedial cortex change. RESULTS: Anteromedial cortical support failure was noted in 46 cases (29%). There was no significant difference between the two groups concerning age, sex, side injury, TAD, Cal-TAD, Parker ratio, or NSA. There was a significant difference in the AO/OTA fracture classification in univariate analysis but no difference in the multivariable analysis. The reduction quality score, calcar fracture gapping in the AP (anteroposterior), and lateral views were significantly associated with anteromedial cortical support failure in follow-up after cephalomedullary nailing in the multivariable analysis. The threshold value of calcar fracture gapping for the risk of loss was 4.2 mm in the AP and 3.8 mm in the lateral fluoroscopies. Mechanical complications (lateral sliding and varus) were frequently observed in the negative anteromedial cortical support group. CONCLUSIONS: Good reduction quality was a protective factor, and larger calcar fracture gapping in the AP and lateral views were risk factors leading to the postoperative loss of anteromedial cortical support. Therefore, we should pay close attention to fracture reduction and minimize the calcar fracture gap during surgery.

A Baeyer-Villiger monooxygenase from Cupriavidus basilensis catalyzes asymmetric synthesis of (R)-lansoprazole and other pharmaco-sulfoxides.

Biocatalytic synthesis of pharmaco-chiral sulfoxides has gained interest in recent years for its environmental friendliness. However, only a few natural biocatalysts can be used for the efficient synthesis of pharmaco-sulfoxides, including (R)-lansoprazole, a chiral proton pump inhibitor used to treat gastrointestinal diseases. In this study, the sequence of BoBVMO (Baeyer-Villiger monooxygenase from Bradyrhizobium oligotrophicum) was used as a probe to identify BVMOs via genomic mining for the highly efficient synthesis of (R)-lansoprazole and other pharmaco-sulfoxides. After virtual sequence filtering, target gene cloning, heterologous expression, and activity screening for lansoprazole sulfide (LPS) monooxygenation, seven new BVMOs were identified among more than 10,000 homologous BVMOs. According to the conserved sequence and phylogenetic tree analysis, these discovered enzymes belong to the family of type I BVMOs and the ethionamide monooxygenase subtype. Among them, CbBVMO, Baeyer-Villiger monooxygenase from Cupriavidus basilensis, showed the highest efficiency and excellent enantioselectivity for converting LPS into (R)-lansoprazole. Moreover, CbBVMO showed a wide substrate spectrum toward other bulky prazole-family sulfides. The results indicate that CbBVMO is a potential enzyme for extending the application of BVMOs in pharmaceutical industry. KEY POINTS: • CbBVMO is the most efficient biocatalyst for (R)-lansoprazole biosynthesis. • CbBVMO catalyzes the conversion of various bulky prazole sulfides. • CbBVMO is a promising enzyme for the biosynthesis of pharmaco-sulfoxides.

A new fluoroscopic view for evaluation of anteromedial cortex reduction quality during cephalomedullary nailing for intertrochanteric femur fractures: the 30° oblique tangential projection.

BACKGROUND: Anteromedial cortex-to-cortex reduction is a key parameter for stable reconstruction of the fracture fragments during the intertrochanteric fracture fixation. This paper introduces the oblique fluoroscopic projection as a novel method to evaluate the quality of anteromedial cortical apposition. METHODS: Three proximal femur specimens were marked with steel wires along five anatomic landmarks: Greater trochanter, Lesser trochanter, Intertrochanteric line, Anterolateral tubercle and the Anteromedial cortical line. After obtaining the standard femoral neck AP and lateral fluoroscopic images, the C-arm was rotated by every 5°increments until a clear tangential view of the antero-medial-inferior corner cortex was observed. 98 cases of intertrochanteric hip fractures were enrolled from April 2018 to October 2019. After fixation with the nails, the intra-operative anteromedial cortex reduction quality was evaluated from the AP, the true lateral, and the new anteromedial oblique fluoroscopic images. The fluoroscopic results were compared with the post-operative 3D-CT reconstruction images. RESULTS: The specimen study showed that internal rotation of the C-arm to approximately 30 ° can remove all the obscure shadows and clearly display the antero-medial-inferior cortical tangent line. Clinically,the positive, neutral and negative apposition of different cortices via intra-operative fluoroscopic images showed79, 19 and 0 cases of medial cortical apposition in AP views; 2, 68 and 28 cases of anterior cortices in lateral views;and 22, 51 and 25cases of anteromedial cortical apposition in oblique views respectively. The post-operative 3D-CT reconstruction images revealed that the final anteromedial cortical contact was noted in 62 cases (63.3%), and lost in 36 cases (36.7%). The overall coincidence rate between intra-operative fluoroscopy and post-operative 3D-CT was 63.3% (62/98) in AP view,79.6% (78/98) in lateral view, and 86.7% (85/98) in oblique view(p < 0.001). Negative cortical apposition in oblique view was highly predictive of a final loss of cortical support on 3D CT (24/25 cases, 96%).And non-negative cortical apposition in oblique view was highly associated with true cortical support on 3D CT images (61/73 cases, 83.6%) (p < 0.001). CONCLUSIONS: Besides the AP and lateral projections, an anteromedial oblique view of 30° certifies to be a very useful means for evaluation of the fracture reduction quality of anteromedial cortical apposition.

Distally Based Sural Adipofascial Turnover Flap for Coverage of Complicated Wound in the Foot and Ankle Region.

BACKGROUNDS: Distally based perforator propeller flap from the lower leg region is a versatile local reconstructive technique for the foot and ankle defects. However, flap venous congestion remains a tough nut to crack. We hypothesize that raising an adipofascial flap with turnover mode of transposition can improve venous drainage and enhance flap safety. METHODS: Based on the 2 rows of septocutaneous perforators in the posterior distal third of the lower leg, distally based adipofascial flap was raised from medial sural region nourished by 1 perforator bundle from the posterior tibial artery or from the lateral sural region from the peroneal artery. The superficial dissection was performed in subdermal plane and deep in to the subfascial space. The flap was nourished by perforator-plus-adipofascial pedicle and turned over 180 degrees upside down to reach the distal wounds. One week later, a split-skin graft was used to cover the exposed fascial flap. Postoperatively, flap survival, complications, and patient functional recovery were evaluated. RESULTS: Distally based sural turnover adipofascial flaps were used in 12 cases with complicated wounds of the distal third lower leg, foot, and ankle region. All wounds were caused by trauma and experienced fracture implants fixation and 5 with osteomyelitis. The comorbidities include diabetes in 9 cases and smoking in 7. There were 8 medial ural flaps and 4 lateral sural flaps. The adipofiscial flaps measured from 6.0 cm × 5.0 cm to 17.0 cm × 6.0 cm (mean, 61.3 cm). Postoperatively, all flaps survived uneventfully without any complication such as flap ischemia and/or necrosis. Two minor donor site complications were encountered, one was postoperative hematoma, and another was hyperproliferative scar. After a mean of 14.6 months of follow-up, the adipofascial flap plus skin graft showed a durable esthetic coverage, with normal shoe wearing and walking. CONCLUSIONS: Distally based sural adipofascial turnover flap is a simple and reliable wound coverage technique. It avoids venous congestion as usually seen in distally based fasciocutaneous flaps.

Lesser Trochanteric Fragments in Unstable Pertrochanteric Hip Fractures: A Morphological Study Using Three-Dimensional Computed Tomography (3-D CT) Reconstruction.

BACKGROUND The lesser trochanter (LT) posterior cortical extension (LTPE) fragment is important for joint stability during reconstruction in unstable pertrochanteric hip fractures. This study aimed to investigate the morphological characteristics of the LT fragments using three-dimensional computed tomography (3-D CT) reconstruction and to compare clinical outcomes in different subgroups of 31A2 fractures. MATERIAL AND METHODS A retrospective study included CT images of 58 cases of 31A2 type unstable pertrochanteric fractures, using the Arbeitsgemeinschaft für Osteosynthesefragen and Orthopedic Trauma Association (AO/OTA) classification. After 3-D CT reconstruction, all the displaced fragments were reduced and the morphologic parameters of the LT fragments were measured. RESULTS At the mid-level of the LT, the mean cortical extension of the LT fragment was 33.5 mm in the posterior wall (83%), 19.0 mm in the medial wall (53%). The mean distal cortical extension from the lower edge of the LT was 13.0 mm. The LT fragment occupied 38% of the whole cortical circumference. Comparison of the subgroups showed that the LT fragment of A2.3 had a larger cortical extension in the posterior, medial, and distal cortex. The mean fracture collapse was 4.7 mm in A2.2 fractures and 5.4 mm in A2.3 fractures (p=0.311). Despite the increased size of the LT fragment in subtype A2.3 fracture compared with subtype A2.2 fracture, this did not influence the clinical outcome. CONCLUSIONS The 3-D morphology of the LT fragment from CT imaging provided a better understanding of the characteristics of subgroups of unstable pertrochanteric fractures, which may improve and guide implant choice.

Anteromedial cortical support reduction in unstable pertrochanteric fractures: a comparison of intra-operative fluoroscopy and post-operative three dimensional computerised tomography reconstruction.

PURPOSE: Anteromedial cortical support reduction is favourable for secondary stability after limited sliding in unstable pertrochanteric fractures. The aim of this study was to compare the accuracy and agreement between intra-operative fluoroscopy and post-operative 3D reconstruction. MATERIALS AND METHODS: A retrospective analysis of 28 patients (mean 81.6 years) treated with short cephalomedullary nails was performed. All patients had full sets of intra-operative fluoroscopy and post-operative 3D CT images. Observation was focused on the position of the anteromedial cortices of the inferior corner between the head-neck fragment and femoral shaft, and their relationship was categorised into three types: positive, neutral and negative. The percentage of subsequent changes in cortical reduction quality between fluoroscopy and 3D CT was calculated and compared. RESULTS: There were 24 positive (85.7%), four neutral and no negative positions in the anteroposterior (AP) view and one positive, 20 neutral (71.4%) and seven negative positions in the lateral view from fluoroscopy. On post-operative 3D CT images with a full range of rotation, definitive anteromedial cortical contact (positive and neutral support) was observed in 18 cases (64.3%). Ten cases lost the anteromedial cortical buttress. With the posteromedial region of the lesser trochanter detached, a positive AP cortical position combined with a positive/neutral lateral position on fluoroscopy (17 cases) was highly predictive of reliable, definitive cortical support (15 cases, 88.2%) on 3D CT. A negative lateral position on fluoroscopy (seven cases), regardless of the combination in the AP view, was likely to predict the final loss of cortical support (six cases, 85.7%) on 3D CT; a positive/neutral lateral position (21 cases) was only associated with loss of support in four cases (19.1%) (p < 0.05). CONCLUSIONS: A lateral negative position of the anterior cortex on fluoroscopy for unstable pertrochanteric fractures may be highly predictive of post-operative final loss of the anteromedial cortical buttress, which should be avoided during operation.

[Clinical manifestations and genetic diagnosis of paroxysmal kinesigenic dyskinesia].

The clinical manifestations of five children with paroxysmal kinesigenic dyskinesia (PKD) were retrospectively analyzed and their gene mutations were analyzed by high-throughput sequencing and chromosome microarray. The 5 patients consisted of 4 males and 1 female and the age of onset was 6-9 years. Dyskinesia was induced by sudden turn movement, scare, mental stress, or other factors. These patients were conscious and had abnormal posture of unilateral or bilateral extremities, athetosis, facial muscle twitching, and abnormal body posture. The frequency of onset ranged from 3-5 times a month to 2-7 times a day, with a duration of <30 seconds every time. Electroencephalography showed no abnormality in these patients. Three patients had a family history of similar disease. The high-throughput sequencing results showed that a heterozygous mutation in the PRRT2 gene, c.649_650insC (p.R217PfsX8), was found in two patients; the mutation c.436C>T (p.P146S) was found in one patient; a splice site mutation, IVS2-1G>A, was found in one patient. The two mutations c.436C>T and IVS2-1G>A had not been reported previously. The chromosome microarray analysis was performed in one patient with negative results of gene detection, and the chromosome 16p11.2 deletion (0.55 Mb) was observed. Low-dose carbamazepine was effective for treatment of the 5 patients. PKD is a rare neurological disease. The detection of the PRRT2 gene by multiple genetic analysis can help the early diagnosis of PKD.

[Association between gene polymorphism of CD40 gene and coronary artery lesion in Kawasaki disease].

OBJECTIVE: To study the association between two single nucleotide polymorphisms (rs4810485 and rs1535045 in CD40 gene) and Kawasaki disease (KD) in Han Chinese children. METHODS: A case-control study was performed on 184 children with KD and 206 normal controls. The polymorphisms of two SNPs in CD40 gene were detected using PCR-RFLP. RESULTS: There were no significant differences in the genotype distribution and allele frequency of SNP rs4810485 in CD40 gene between the KD and normal groups (P>0.05). The genotype distribution of SNP rs1535045 in CD40 gene in the KD group was significantly different from the control group (P<0.05). T allele of SNP rs1535045 was shown as a risk factor for development of KD (OR=1.592, 95%CI: 1.182-2.144, P=0.004). There were no association between the polymorphisms of the two SNPs and coronary artery lesions (P>0.05). CONCLUSIONS: SNP rs1535045 may be associated with the development of KD in Han Chinese children, while SNP rs4810485 may not.

Discovery and Engineering of a Bacterial (+)-Pulegone Reductase for Efficient (-)-Menthol Biosynthesis.

The biosynthesis of valuable plant-derived monoterpene (-)-menthol from readily available feedstocks (e. g., (-)-limonene) is of great significance because of the high market demand for this product. However, biotransforming (+)-pulegone into (-)-menthone, the (-)-menthol precursor, through (+)-pulegone reductase (PGR) catalysis is inefficient because of the poor protein expression or catalytic efficiency (kcat/Km) of plant origin PGRs. In this study, a novel bacterial PGR from Pseudomonas resinovorans (PrPGR) was identified, and the most successful variant, PrPGRM2-1 (A50 V/G53 W), was obtained, showing respective 20-fold and 204-fold improvements in specific activity and catalytic efficiency. PrPGRM2-1 was employed to bioreduce (+)-pulegone, resulting in 4.4-fold and 35-fold enhancements in (-)-menthone titers compared with the bioreductions catalyzed by wild-type (WT) PrPGR and MpPGR, respectively. Furthermore, a whole-cell biocatalyst containing PrPGRM2-1, MpMMR, and BstFDH was constructed and achieved the highest (-)-menthol titer reported to date without externally supplemented NADPH/NADP+. Overall, this study details an efficient PGR with high catalytic efficiency that possesses great potential for (-)-menthol biosynthesis.

Morphological characteristics and a new classification system of the inferior pole fracture of the patella: A computer-tomography-based study.

PURPOSE: The objective of this study was to measure the morphological characteristics of inferior pole fracture of the patella (IPFP) and develop a practical classification system to determine the corresponding treatment protocols for different IPFPs with specific patterns. METHODS: A retrospective radiographic review was performed on a series of 71 patients with IPFP. The preoperative CT data were collected and measured using image processing software. The number of fragments, maximum fracture fragment anteroposterior length (MFFAL), maximum fracture fragment transverse length (MFFTL), fracture fragment coronal angle (FFCA), fracture fragment sagittal angle (FFSA), maximum fracture fragment height (MFFH) and maximum transverse sectional area (MTSA) were analysed. RESULTS: The mean number of fracture fragments was 3.8. The average MFFAL was 14.9 mm, the average MFFTL was 23.5 mm, the average FFCA was 92.1°, the average FFSA was 93.0°, the average MFFH was 13.6 mm, and the average MTSA was 299.3 mm2. A new classification system was introduced to describe the varied patterns of IPFP, summarized as (I) simple IPFP; (II) comminuted IPFP; (III) simple IPFP with simple patellar body fracture; and (IV) comminuted patellar fracture involving the inferior pole. With the four-type classification system, 12 type I, 22 type II, 21 type III, and 16 type IV lesions were observed, each with specific morphological characteristics. CONCLUSION: Most IPFPs exhibited a diversiform pattern, demonstrating that coverage fixation was likely needed. The four-type classification system might offer a valuable approach to help orthopaedic surgeons make individual treatment plans.

Treatment of posterolateral tibial plateau fractures: a narrative review and therapeutic strategy.

The posterolateral tibial plateau is crucial for maintaining knee stability during flexion, and fractures in this area often involve ligament and meniscus injuries, necessitating effective management. However, treating posterolateral tibial plateau fractures (PLF) poses significant challenges due to the complex anatomy. Therefore, this review aims to explore contemporary concepts of PLF, from identification to fixation, and proposes a comprehensive treatment strategy. In this article, the authors detail the injury mechanisms, fracture morphology, PLF classification systems, surgical approaches, and techniques for open reduction and internal fixation (ORIF) as well as arthroscopic-assisted internal fixation (ARIF). The findings indicate that PLF is typically caused by flexion-valgus forces, resulting in depression or split-depression patterns. For isolated PLF, the supra-fibular head approach is often preferable, whereas posterior approaches are more suitable for combined fractures. Additionally, innovative plates, particularly the horizontal belt plate, have shown satisfactory outcomes in treating PLF. Currently, the 'bicondylar four-quadrant' concept is widely used for assessing and managing the tibial plateau fractures involving PLF, forming the cornerstone of the comprehensive treatment strategy. Despite challenges in surgical exposure and implant placement, ORIF remains the mainstream treatment for PLF, benefiting significantly from the supra-fibular head approach and the horizontal belt plate. Furthermore, ARIF has proven effective by providing enhanced visualization and surgical precision in managing PLF, emerging as a promising technique.

Importance of the Posterior Plate in Three-Column Tibial Plateau Fractures: A Finite Element Analysis and Clinical Validation.

OBJECTIVE: Dual-plate fixation was thought to be the gold standard for treating complicated bicondylar tibial plateau fractures, yet it was found to be hard to accommodate the posterior column in three-column fractures. Currently, column-specific fixation is becoming more and more recognized, but no comprehensive investigation has been performed to back it up. Therefore, the objective of this study was to validate the importance of posterior column fixation in the three-column tibial fractures by a finite element (FE) analysis and clinical study. METHODS: In FE analysis, three models were developed: the longitudinal triple-plate group (LTPG), the oblique triple-plate group (OTPG), and the dual-plate group (DPG). Three loading scenarios were simulated. The distribution of the displacement and the equivalent von Mises stress (VMS) in each structure was calculated. The comparative measurements including the maximum posterior column collapse (MPCC), the maximum total displacement of the model (MTD), the maximum VMS of cortical posterior column (MPC-VMS), and the maximum VMS located on each group of plates and screws (MPS-VMS). The clinical study evaluated the indicators between the groups with or without the posterior plate, including operation time, blood loss volume, full-weight bearing period, Hospital for Special Surgery Knee Scoring system (HSS), Rasmussen score, and common postoperative complications. RESULTS: In the FE analysis, the MPCC, the MPC-VMS, and the MTD were detected in much lower amounts in LTPG and OTPG than in DPG. In comparison with DPG, the LTPG and OTPG had larger MPS-VMS. In the clinical study, 35 cases were included. In the triple-plate (14) and dual-plate (21) groups, the operation took 115.6 min and 100.5 min (p < 0.05), respectively. Blood loss in both groups was 287.0 mL and 206.6 mL (p < 0.05), and the full-weight bearing period was 14.5 weeks and 16.2 weeks (p < 0.05). At the final follow-up, the HSS score was 85.0 in the triple-plate group and 77.5 in the dual-plate (p < 0.05), the Rasmussen score was 24.1 and 21.6 (p < 0.05), there were two cases with reduction loss (9.5%) in the dual-plate group and one case of superficial incision infection found in the triple-plate group. CONCLUSION: The posterior implant was beneficial in optimizing the biomechanical stability and functional outcomes in the three-column tibial plateau fractures.

Tension-band wiring through a single cannulated screw combined with suture anchors to treat inferior pole fracture of the patella.

PURPOSE: To evaluate the feasibility and clinical outcomes of tension-band wiring through a single cannulated screw combined with two suture anchors in treating inferior pole fracture of the patella. METHODS: Between September 2018 and September 2021, a total of 22 patients with a mean age of 55 years who sustained inferior pole fracture of the patella and were treated by tension-band wiring through a single cannulated screw combined with two suture anchors were enrolled. X-ray radiographs were performed to observe the bone union time. The duration of each operation was recorded to reflect the complexity of surgical treatment. Functional measurements, comprising range of motion (ROM), the Böstman scale, and the Knee Injury and Osteoarthritis Outcome Score (KOOS), were taken. Postoperative complications including fixation failure, incision infection, loss of reduction, and malunion were evaluated. RESULTS: All patients were followed up for an average of 17 months (range: 12-25 months). The average clinical bone union time was 8 weeks (range: 6-12 weeks), and the radiographic bone union time was 11 weeks (range: 8-12 weeks). At the final follow-up, the mean ROM was 136° (range: 115°-140°), the KOOS was 85 (range: 68-100) and the Böstman score was 28 (range: 20-30); these outcomes were classified as excellent in 17 cases and good in 5 cases, with no instances of poor results. Loss of reduction occurred in one case, while no cases of incision infection, fixation failure or malunion were observed. CONCLUSION: For inferior pole fracture of the patella, tension-band wiring through a single cannulated screw combined with suture anchors can offer sufficient fixation stability to achieve a satisfactory clinical outcome with reduced operational complexity; this procedure should be recommended in clinical practice.

Research on Elastic and Elastic-Plastic Buckling Load of Cylindrical Shell with an Inclined through Crack under Axial Compressive Load.

By experimental methods, 26 specimens were designed to conduct elastic and elastic-plastic buckling tests on cylindrical shells containing cracks. This study discusses the influence of factors such as the length-diameter ratio, the diameter-thickness ratio, the crack length, the inclination of the crack, etc., on the buckling load. Additionally, finite element models were established to compare with experimental results. For the PMMA cylindrical shell, the results showed that as the length-diameter ratio of the cylindrical shell increased, the buckling load first decreased and then increased. For the 6063 aluminum alloy cylindrical shell, with increasing length-diameter ratio, diameter-thickness ratio, and crack length of the cylindrical shell, the buckling load decreased accordingly. However, concerning the crack inclination, as the crack inclination increased, the buckling load increased accordingly. This indicates that the larger the crack inclination, the higher the load capacity of the cylindrical shell containing cracks. Through finite element simulations of cylindrical shells with cracks, it was found that through compressive mechanical properties, both elastic and elastic-plastic buckling loads yielded results that are closer to the experimental results. Additionally, the inclusion of contact effects in numerical simulations further improved the agreement with the experimental results, and the variation trend of the buckling load in the finite element simulation was consistent with the experimental results. The research findings provide valuable references for the assessment of load capacity in structures containing cracks.

Separate vertical wiring plus bilateral anchor girdle suturing fixation for the fractures of the inferior pole of the patella.

BACKGROUND: The fixation of inferior pole fractures of the patella (IPFPs) is still a great challenge for surgeons. MATERIALS AND METHODS: We introduced a new fixation method for IPFP fixation, that is, separate vertical wiring plus bilateral anchor girdle suturing fixation (SVW-BSAG). Three finite element models including the anterior tension band wiring (ATBW) model, separate vertical wiring (SVW) model and SVW-BSAG model, were built to evaluate the fixation strength of different fixation methods. A total of 41 consecutive patients with IPFP injury were enrolled in this retrospective study, including 23 patients in the ATBW group and 18 patients in the SVW-BSAG group. The operation time, radiation exposure, full weight-bearing time, Bostman score, extension lag versus contralateral healthy leg, Insall-Salvati ratio, and radiograph outcomes were employed to assess and compare the ATBW group and SVW-BSAG group. RESULTS: The finite element analysis confirmed that the SVW-BSAG fixation method was as reliable as the ATBW fixation method in terms of fixed strength. Through retrospective analysis, we found that there was no significant difference between the SVW-BSAG and ATBW groups in age, sex, BMI, fracture side, fracture type, or follow-up time. There were no significant differences between the two groups in the Insall-Salvati ratio, 6-month Bostman score, and fixation failure. Compared with the ATBW group, the SVW-BSAG group showed advantages in intraoperative radiation exposure, full weight-bearing time, and extension lag versus the contralateral healthy leg. CONCLUSION: The finite element analysis and clinical results showed that SVW-BSAG fixation methods are a reliable and valuable for IPFP treatment.