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.

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.

Two-Part Intertrochanteric Femur Fractures with Bisection of the Lesser Trochanter: An Irreducible Fracture Pattern.

Objective: To introduce the clinical features of and surgical techniques for a rare type of irreducible pertrochanteric femur fracture pattern with bisection of the lesser trochanter. Methods: From January 2017 to December 2019, 357 patients with per/intertrochanteric femur fractures underwent surgery by closed reduction and internal fixation, of whom 12 patients were identified with rare preoperative imaging features, the lesser trochanter was almost equally bisected. The main fracture pathoanatomy of these cases included: The anterior fracture line passed along the intertrochanteric line to the medial lesser trochanter and bisected it into 2 equal parts from mid-level of the lesser trochanteric protrusion. The proximal part of the lesser trochanter connected to the head-neck fragment and attached by the psoas major tendon, while the distal part of the lesser trochanter connected to the femoral shaft and attached by the tendon of the iliac muscle. These fractures were irreducible by a closed maneuver and were reduced with limited assistance by some devices, and short intramedullary nails were used for fixation of these fractures. Results: All patients were followed up for an average of 14.2 ± 2.1 months. Clinical fracture union occurred at an average of 10.8 ± 1.5 weeks, while radiographic union occurred at an average of 12.7 ± 1.2 weeks. No cut out of the helical blade was visible on radiographs. The average Parker-Palmer score was 6.9 ± 1.3 (range, 5-9) at the last follow up, including 8 cases rated as excellent, 2 as good and 2 as fair. Conclusion: Two-part pertrochanteric femur fractures with bisection of the lesser trochanter have an irreducible fracture pattern with cortical locking and soft tissue incarceration. Soft tissue release and short cephalomedullary nail fixation for this fracture pattern provide stable fixation and allow early exercise. This treatment appears to have excellent outcomes in the short and medium terms.

Increased Anxiety-like Behaviors in Adgra1-/- Male But Not Female Mice are Attributable to Elevated Neuron Dendrite Density, Upregulated PSD95 Expression, and Abnormal Activation of the PI3K/AKT/GSK-3ß and MEK/ERK Pathways.

Adhesion G protein-coupled receptor A1 (ADGRA1) belongs to the G protein-coupled receptor (GPCR) family, and its physiological function remains largely unknown. We found that Adgra1 is highly and exclusively expressed in the brain, suggesting that Adgra1 may be involved in the regulation of neurological behaviors including anxiety, depression, learning and memory. To this end, we comprehensively analyzed the potential role of ADGRA1 in the neurobehaviors of mice by comparing Adgra1-/- and their wild-type (wt) littermates. We found that Adgra1-/- male but not female mice exhibited elevated anxiety levels in the open field, elevated plus maze, and light-dark box tests, with normal depression levels in the tail-suspension and forced-swim tests, and comparable learning and memory abilities in the Morris water maze, Y maze, fear condition, and step-down avoidance tests. Further studies showed that ADGRA1 deficiency resulted in higher dendritic branching complexity and spine density as evidenced by elevated expression levels of SYN and PSD95 in amygdalae of male mice. Finally, we found that PI3K/AKT/GSK-3ß and MEK/ERK in amygdalae of Adgra1-deficient male mice were aberrantly activated when compared to wt male mice. Together, our findings reveal an important suppressive role of ADGRA1 in anxiety control and synaptic function by regulating the PI3K/AKT/GSK-3ß and MEK/ERK pathways in amygdalae of male mice, implicating a potential, therapeutic application in novel anti-anxiety drug development.

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.

Sub-Classification of AO/OTA-2018 Pertrochanteric Fractures Is Associated With Clinical Outcomes After Fixation of Intramedullary Nails.

BACKGROUND: The new edited AO/OTA-2018 classification of pertrochanteric fractures was revised and no longer based on the status of lesser trochanter. This paper aimed to explore the clinical and technical outcomes among the subgroups (31A1 and 31A2) of the new classification treated with cephalomedullary nails. METHODS: A retrospective research of 154 patients diagnosed with pertrochanteric fractures (AO/OTA-2018 31A1.2/3 and 31A2.1/2/3) treated with intramedullary nails was conducted. The baseline data and outcomes were compared among the subgroups. The outcomes included tip-apex distance (TAD), Cal-TAD, Parker ratio, neck shaft angle (NSA), blood loss, varus displacement, and over lateral sliding rate of the blade. RESULTS: There were 154 cases involving 48 males and 106 females. The average age was higher in the sub-classifications of A2.2 and A2.3 than A1.2. Furthermore, the subgroups of A2.2 and A2.3 presented inferior outcomes with regard to blood loss and reduction quality score than A1.2 and A1.3. The subgroup of A2.3 was further poor with respect to calcar fracture gapping in the anteroposterior view and excessive lateral migration occurrence rate than A1.2. CONCLUSIONS: Complex pertrochanteric fractures indicated inferior outcomes compared to simple sub-classifications, which might lead by the incompetent of lateral wall and instability of the fracture. The newly proposed AO/OTA-2018 classification was conductive to forecast the prognosis.

ADGRA1 negatively regulates energy expenditure and thermogenesis through both sympathetic nervous system and hypothalamus-pituitary-thyroid axis in male mice.

Adhesion G protein-coupled receptor A1 (ADGRA1, also known as GPR123) belongs to the G protein-coupled receptors (GPCRs) family and is well conserved in the vertebrate lineage. However, the structure of ADGRA1 is unique and its physiological function remains unknown. Previous studies have shown that Adgra1 is predominantly expressed in the central nervous system (CNS), indicating its important role in the transduction of neural signals. The aim of this study is to investigate the central function of Adgra1 in vivo and clarify its physiological significance by establishing an Adgra1-deficient mouse (Adgra1-/-) model. The results show that Adgra1-/- male mice exhibit decreased body weight with normal food intake and locomotion, shrinkage of body mass, increased lipolysis, and hypermetabolic activity. Meanwhile, mutant male mice present elevated core temperature coupled with resistance to hypothermia upon cold stimulus. Further studies show that tyrosine hydroxylase (TH) and ß3-adrenergic receptor (ß3-AR), indicators of sympathetic nerve excitability, are activated as well as their downstream molecules including uncoupling protein 1 (UCP1), coactivator 1 alpha (PGC1-α) in brown adipose tissue (BAT), and hormone-sensitive lipase (HSL) in white adipose tissue (WAT). In addition, mutant male mice have higher levels of serum T3, T4, accompanied by increased mRNAs of hypothalamus-pituitary-thyroid axis. Finally, Adgra1-/- male mice present abnormal activation of PI3K/AKT/GSK3ß and MEK/ERK pathways in hypothalamus. Overexpression of ADGRA1 in Neuro2A cell line appears to suppress these two signaling pathways. In contrast, Adgra1-/- female mice show comparable body weight along with normal metabolic process to their sex-matched controls. Collectively, ADGRA1 is a negative regulator of sympathetic nervous system (SNS) and hypothalamus-pituitary-thyroid axis by regulating PI3K/AKT/GSK3ß and MEK/ERK pathways in hypothalamus of male mice, suggesting an important role of ADGRA1 in maintaining metabolic homeostasis including energy expenditure and thermogenic balance.

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.

A reliable method for intraoperative detection of lateral malleolar malrotation using conventional fluoroscopy.

OBJECTIVE: To introduce a new method for intraoperative detection of rotational malreduction of the lateral malleolus using conventional fluoroscopy. MATERIAL AND METHODS: From January 2014 to December 2017, 56 Weber type C unstable lateral malleolar fractures with syndesmosis injury were identified. The fibular fracture patterns were simple oblique or transverse in 20, comminuted in 25, and Maisonneuve injury with fibular neck fractures in 11 cases. 47 cases were operated with ORIF, and 9 cases of Maisonneuve fractures were operated with CRIF. The mortise view of the contralateral uninjured ankle was used for intraoperative comparison. Two indexes were applied for fluoroscopic detection of distal fibula malrotation, i.e. the contour profile change in lateral malleolar shape, and the intrinsic structure appearance of lateral malleolar fossa cortex. Postoperative talofibular joint congruency was measured on axial CT scan to confirm the reduction quality. RESULTS: Using the two radiographic parameters for intraoperative fluoroscopic evaluation, we finally achieved satisfying reduction and fixation of the lateral malleolus in all 56 cases. A more spoon-shaped fibula profile and disappearance of the lateral fossa cortex shadow indicates an internal rotation, while a more pointed blade-shaped fibula profile and disappearance of lateral fossa cortex shadow indicates an external rotation. Postoperative CT scanning identified distal fibular no rotation in 44 cases (78.6%), mild rotation less than 5° in 12 cases (21.4%), with 7 cases internal rotation (mean 3.1°) and 5 cases external rotation (mean 2.8°). CONCLUSION: Using conventional intraoperative fluoroscopy on mortise view, new radiographic parameters can provide reliable method to detect rotational malreduction of the lateral malleolus.

Inferior calcar buttress reduction pattern for displaced femoral neck fractures in young adults: a preliminary report and an effective alternative.

BACKGROUND: Fracture reduction quality is of paramount importance for osteosynthesis. The aim of this study was to report the outcome of an inferior cortical buttress non-anatomic reduction pattern and internal fixation for displaced femoral neck fractures (Garden types III and IV) in young adults. METHODS: A retrospective analysis of 46 displaced femoral neck fractures was performed, which were treated by closed reduction and internal fixation with parallel cannulated screws. There were 20 males and 26 females, with an average age of 50.3 years (19-60). According to the inferior cortical reduction quality seen in recorded intraoperative fluoroscopy, the patients were divided into two groups. Group I (n = 30) was anatomic cortical apposition as the two inferior cortices were smoothly contacted, and group II (n = 16) was buttress cortical apposition as the two inferior cortices were located in positive support contact (Gotfried reduction pattern). With a mean follow-up of 22.0 months, femoral neck length, neck-shaft angle, and clinical outcomes were compared. RESULTS: Thirty-nine patients (84.8%) achieved uneventful fracture union. Complications occurred in seven patients, six in group I (20%) and one in group II (6.3%), including displacement to varus, neck shortening, early fixation failure, nonunion, and avascular necrosis of the femoral head. No significant difference existed in the complication rate between the two groups (p = 0.216). Four patients (13.3%) in group I were converted to prosthetic replacement, but none in group II. CONCLUSIONS: For closed reduction and fixation of displaced femoral neck fractures in young adults, an inferior cortical buttress reduction pattern, though non-anatomic, can produce sustainable fracture stability and predictable clinical outcomes.

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.