Urolithin a attenuates IL-1ß-induced inflammatory responses and cartilage degradation via inhibiting the MAPK/NF-κB signaling pathways in rat articular chondrocytes.

BACKGROUND: Osteoarthritis (OA) is characterized by inflammation and extracellular matrix (ECM) degradation and is one of the most common chronic degenerative joint diseases that causes pain and disability in adults. Urolithin A (UA) has been widely reported for its anti-inflammatory properties in several chronic diseases. However, the effects of UA on OA remain unclear. The aim of the current study was to investigate the anti-inflammatory effects and mechanism of UA in interleukin-1ß (IL-1ß)-induced chondrocytes. RESULTS: No marked UA cytotoxicity was noted, and UA protected cartilage from damage following IL-1ß stimulation in micromasses. Moreover, UA promoted the expression of anabolic factors including Sox-9, Collagen II, and Aggrecan while inhibiting the expression of catabolic factors such as matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4) in rat chondrocytes. Protective effects of UA were also observed in ex vivo organ culture of articular cartilage. Mechanistically, IL-1ß significantly activated and upregulated the expression of p-ERK 1/2, p-JNK, p-P38, and p-P65, while UA protected chondrocytes against IL-1ß-induced injury by activating the mitogen-activated kinase (MAPK)/nuclear factor-κB (NF-κB) signaling pathways. CONCLUSION: Our results provide the evidence that UA could attenuate IL-1ß-induced cell injury in chondrocytes via its anti-inflammatory action. UA may be a promising therapeutic agent in the treatment of OA.

Combined approaches for fixation of Schatzker type II tibial plateau fractures involving the posterolateral column: a prospective observational cohort study.

INTRODUCTION: This study aimed to investigate the surgical techniques and the clinical efficacy of combined approaches for the treatment of Schatzker type II tibial plateau fractures involving the posterolateral column [lateral and posterolateral columns (LPCs) fractures] in a prospective cohort. MATERIALS AND METHODS: From January 2007 through December 2010, a total of 65 patients with LPCs underwent dual-plate fixation via a combined anterior and posterior approach. The anterior and posterior approaches were the conventional anterolateral approach and a posteromedial inverted L-shaped approach, respectively, with the patients in a floating position. RESULTS: Ultimately, 41 patients were followed up for a mean period of 52.5 months. All fractures healed. The mean time to radiographic bony union was 15.2 weeks and the mean time to full weight-bearing was 18.7 weeks. No parameter associated with knee alignment changed significantly between immediately postoperation and 2 years postoperation. No collapse of the reduced articular surface was detected. Two years postoperation, the mean Hospital for Special Surgery score was 92.3; the mean Short Form-36 score was 90.1, and the mean range of knee motion was 1.7°-123.6° (extension-flexion). Two patients suffered dehiscence of the anterolateral incision and another suffered partial necrosis at the margin of the posteromedial incision postoperatively. All healed in response conservative treatment. Another two patients experienced numbness in the posteromedial inferior region of the calf. No implant loosening, breakage, fixation failure, or other complication was observed during follow-up. CONCLUSIONS: LPCs are not uncommon. Careful preoperative analysis of computed tomography images and impeccable preparation are necessary to avoid neglecting a posterolateral column fracture. It is inappropriate to generalize one scenario for all Schatzker type II fractures: a single approach cannot address all subtypes of these fractures. Dual-plate fixation via a combined approach is an effective treatment for LPCs.

Pathoanatomy and incidence of the posterolateral fractures in bicondylar tibial plateau fractures: a clinical computed tomography-based measurement and the associated biomechanical model simulation.

OBJECTIVES: The aim of our study is to evaluate the incidence and pathoanatomy of posterolateral fragments and analyze the associated fracture mechanism in bicondylar tibial plateau fractures. METHODS: From 1.1.2008 to 3.15.2012, all patients suffering bicondylar tibial plateau fractures were identified, scanned and analyzed at the Shanghai Clinical Trauma Center. Furthermore cadaver knees were selected into three groups of 30/60/90 knee flexion to simulate the posterolateral tibial plateau fracture by an impact device. RESULTS: One hundred and sixty-four (44.32 %) bicondylar tibial plateau fractures finally satisfied our requirements. Fifty-three and ninety-four cases were measured eventually in the groups of posterolateral split and depression. The posterolateral articular fragment proportion was 15.43 %. The posterolateral articular fragment angle showed an average of 12.94°. The posterolateral fragment cortical height was on average 2.96 cm. The posterolateral sagittal fragment angle averaged at 72.06°. Ninety-four cases were measured in the posterolateral depression group. The average posterolateral articular depression proportion was 16.74 %. The average posterolateral articular depression height was 2.47 cm. In the biomechanical modeling of such kinds of fracture patterns, posterolateral split fractures in 30° and 60° flexion are significantly more than those in 90° flexion. Posterolateral splits combined with anterolateral depression fractures in 30° flexion are significantly more than those in 90° flexion. CONCLUSION: The incidence of posterolateral fractures is 44.32 % in bicondylar tibial plateau fractures. The morphology of posterolateral area can be referenced for the surgeon in the future clinical work. The information is also helpful for the design of locking plate and fracture modeling in biomechanical test. In addition, that posterolateral split and posterolateral depression might be caused by different injury mechanisms. Different angles of knee flexion under the axial impact loading are possibly the interpretations for these two fracture patterns.