Potential problem and solution of lateral plate postposition for the posterolateral tibial plateau fracture.

BACKGROUND: There has been controversial for the treatment of the posterolateral tibial plateau fractures (PTPF). This study aimed to evaluate clinic outcomes of the lateral locking compression plate (LCP) postposition, analyze the feasibility of LCP postposition through anatomical measurement, and address the potential problems of LCP postposition through the biomechanical assessment. METHODS: 39 patients with PTPF undergoing LCP fixation between June 2019 and June 2022 were retrospectively evaluated. All cases were divided into two group: Group A (15 cases) employed plate transverse arm postpositioning with posterolateral (PL) fracture fixation using two raft screws, while Group B (24 cases) utilized non-postpositioning with fixation by a single raft screw. Surgical duration, intraoperative blood loss, the change of lateral tibial plateau angle (LTPA), lateral tibial plateau posterior slope angle (LPSA) and fracture collapse between immediate postoperative and last follow up, range of motion (ROM), HSS knee score, and Lysholm knee score were recorded. CT measurements of the fibular head superior space and LCP transverse arm were taken in 50 healthy adult knees to assess postposition feasibility. Finally, three fracture models were established using finite element analysis: Model A with plate postposition and PL split fracture fixed by two raft screws of transverse arm, Model B with plate non-postposition and PL split fracture fixed by one raft screw, and Model C with plate non-postposition and PL split fracture fixed by one raft screw and anterior-posterior tension screws. Loadings of 250N, 500N, and 750N were applied for the analysis of the displacement degree, von Mises stress distribution. RESULTS: Results indicate comparable operative duration and intraoperative hemorrhage between groups. Complications were minimal in both groups. Group A demonstrated superior outcomes in terms of radiographic parameters, functional scores, and fracture collapse prevention. CT measurements revealed compatibility in 72% of healthy knees with the postpositioning technique. Finite element analysis indicated favorable biomechanical stability. CONCLUSION: Not all patients with PTPF were applicable to the management of the plate postposition and two raft screws fixation, even though this technique exerted good biomechanical stability and achieved satisfactory clinic outcomes. When the PL fracture was fixed by only raft screw through LCP owing to various reasons, two anterior-posterior tension screws might be necessitated to maintain the fracture stability.

Biomechanics and finite element analysis comparing posterior T-plates with LCP for fixation of posterolateral tibial plate fractures.

Objective: The treatment for posterolateral tibial plateau fractures (PTPF) have been subjects of controversy. We conducted a study to improve the fixation of PTPF through a lateral approach. Methods: We utilized 40 synthetic tibias and categorized the fracture models into five groups based on the locking compression plate (LCP) and T-distal radius plate (TPP) via various forms of fixation with screws through the posterolateral (PL) fracture fragments. I: Two-screw fixation using two locking screws (LPTL). Ⅱ: Two-screw fixation with both variable angle locking screws (LPTV). Ⅲ: One-screw fixation with one locking screw (LPOL). Ⅳ: One-screw fixation with one locking screw and two anteroposterior lag screws (LPOLTL). Ⅴ: a distal radius plate with three locking screws (TPP). Biomechanical tests were conducted to observe the axial compression displacement of the PL fracture fragments at force levels of 250 N, 500 N, and 750 N, as well as to determine the failure load and the axial stiffness for each respective group. Results: Under a 750 N load condition, the displacements within the five experimental groups exhibited the following trend: Ⅴ < Ⅱ < Ⅰ< Ⅳ < Ⅲ. However, there were no significant differences between Group V and Group II, Group I and Group IV (p > 0.05), and only Group Ⅲ demonstrated a displacement exceeding 3 mm. The failure load and the axial stiffness exhibited the same trend. Conversely, statistical significance was identified among the remaining group compared with Group Ⅲ (p < 0.05). Regarding the finite element analysis, the maximum displacements for the five models under the load of 750 N exhibited the following trend: Ⅴ < Ⅱ < Ⅰ< Ⅳ < Ⅲ. The following trends were observed in maximum von Mises stresses for these models under the load of 750 N: Ⅴ < Ⅱ < Ⅳ< Ⅰ < Ⅲ. Conclusion: It is crucial to address the inadequate mechanical strength associated with single screw fixation of LCP for fixing PL fractures in a clinical setting. The biomechanical strength of two-screw fixation surpasses that of single-screw fixation. Introducing variable-angle screws can further enhance the fixation range. Furthermore, the addition of two lag screws threaded from anterior to posterior can compensate the mechanical stability, when PL fracture is fixed with single screw in clinic.

Incidence and risk factors of isolated calf muscular venous thrombosis after tibial plateau fractures surgery.

BACKGROUND: The risks associated with deep vein thrombosis (DVT) have gained significant recognition over time. A prevalent form of distal DVT is isolated calf muscular venous thrombosis (ICMVT). Despite its common clinical occurrence, data on ICMVT subsequent to tibial plateau fracture (TPF) surgery are scarce. This study aimed to examine the epidemiological characteristics and associated risk factors (RFs) of ICMVT following TPF surgery. METHODS: For this retrospective analysis, we included patients from our hospital, who underwent TPF surgery between March 2017 and March 2021. Patients' electronic medical records were reviewed, including admission details, fracture classification, surgical procedures, and laboratory biomarkers. The HSS (The American Hospital for Special Surgery) and Rasmussen scores were employed to evaluate the clinical effect. A Color Duplex Flow Imager (CDFI) was regularly used to detect pre- and postoperative venous thrombosis in the lower limbs. Finally, uni- and multivariate logistic regression analyses were used to identify independent RFs associated with ICMVT. RESULTS: Overall, 481 participants were recruited for analysis. Postoperative ICMVT occurred in 47 patients. All ICMVTs occurred on the affected side. Four of the 47 ICMVT patients exhibited sudden postoperative swelling in the affected limb. The HSS and Rasmussen scores in the non-ICMVT cohort (87.6 ± 8.2, 16.0 ± 1.7) were markedly different from the ICMVT cohort (84.8 ± 8.2, 15.5 ± 1.6) (p = 0.014, p = 0.031). This study finally identified five postoperative ICMVT-related RFs, which were age (> 55 years old) (OR 3.06; 95% CI 1.47-6.37; p = 0.003), gender (female) (OR 2.67; 95% CI 1.37-5.22; p = 0.004), surgical duration (> 114 min) (OR 3.14; 95% CI 1.44-6.85; p = 0.004), elevated white blood cell content (OR 2.85; 95% CI 1.47-5.51; p = 0.002), and hyponatremia (OR 2.31; 95% CI 1.04-5.12; p = 0.040). CONCLUSION: The epidemiological findings of this study may help predict ICMVT risk after surgery thus facilitating the development of individualized clinical assessments and targeted prevention programs.

Theaflavin-3,3'-Digallate Protects Cartilage from Degradation by Modulating Inflammation and Antioxidant Pathways.

Background: Osteoarthritis (OA) is a common degenerative joint disease that may be closely linked to inflammation and oxidative stress destroying the balance of cartilage matrix. Theaflavin-3,3'-digallate (TFDG), a natural substance derived from black tea, has been reported to restrict the activity of inflammatory cytokines and effectively eliminate reactive oxygen species (ROS) in various diseases. However, it is not clear whether TFDG can improve OA. Methods: Chondrocytes were treated with or without IL-1ß and 20 µM and 40 µM TFDG. The effect of TFDG on the proliferation of chondrocytes was detected by CCK8. RT-qPCR was used to detect the gene expression of inflammatory factors, extracellular matrix synthesis, and degradation genes. Western blot and immunofluorescence assays were used to detect the protein expression. The fluorescence intensity of reactive oxygen species labeled by DCFH-DA was detected by flow cytometry. We established an OA rat model by performing destabilized medial meniscus (DMM) surgery to observe whether TFDG can protect chondrocytes under arthritis in vivo. Results: TFDG was found to inhibit proinflammatory factors (IL-6, TNF-α, iNOS, and PGE) and matrix-degrading enzymes (MMP13, MMP3, and ADAMTS5) expression and protected extracellular matrix components of chondrocytes (ACAN, COL2, and SOX9). TFDG accelerated the scavenging of ROS caused by IL-1ß according to the Nrf2 signaling pathway activation. At the same time, TFDG suppressed the PI3K/AKT/NF-κB and MAPK signaling pathways to delay the inflammatory process. The cartilage of DMM rats receiving TFDG showed lower Osteoarthritis Research Society International (OARSI) scores and expressed higher levels of COL2 and Nrf2 compared with those of rats in the DMM group. Conclusion: TFDG could protect cartilage from degradation and alleviate osteoarthritis in rats, which suggests that TFDG has potential as a drug candidate for OA therapy.

The Study of Biomechanics and Clinical Anatomy on a Novel Plate Designed for Posterolateral Tibial Plateau Fractures via Anterolateral Approach.

There is no consensus about the optimal internal fixation selection for treatment of posterolateral tibial plateau fracture. This study described a novel plate through an anterolateral approach for posterolateral tibial plateau fractures (PTPFs). We evaluated the biomechanical performance of a novel plate and two conventional internal implants and investigated the anatomic feasibility of the novel plate. The fracture models were randomly assigned into six groups: Groups A-C were the model groups of posterolateral split fracture, fixed with the posterior buttress plate, the lateral locking plate, and the novel plate, respectively. Groups D-E were the model groups of posterolateral depression fracture, fixed with the posterior buttress plate, the lateral locking plate, and the novel plate, respectively. We evaluated the biomechanical performance of six model groups by the biomechanical testing and finite element analysis. Progressively increasing axial compressive loads were applied to each synthetic fracture model by using a customized indentor under 250-750 N loads. Meanwhile, we dissected 12 fresh frozen knee specimens and fixed them with the novel plate through the anterolateral approach. We recorded the adjacency of the novel plate to important anatomic structures. Biomechanical testing showed that the novel plate had the least displacement, followed by the posterior buttress plate, and the lateral plate had the most displacement in posterolateral split fracture. There was no significant difference in the displacement between the novel plate and the lateral plate at different loads in posterolateral depression fractures. And the posterior buttress plate showed the most displacement. In the finite element analysis, the maximum stress values of Groups A, B, and C were 383.76, 414.63, and 305.07 MPa under the load of 750 N, respectively. The maximum stress values of Groups D, E, and F were 474.28, 436.31, and 413.4 MPa under the load of 750 N, respectively. In the anatomic study, the placement of the novel plate had a low risk of damage to the important anatomic structures of knee posterolateral corner. The novel plate could be a great choice for the treatment of PTPFs due to better biomechanical performance and easy manipulation.