Bucket handle tears of the medial meniscus: meniscal intrusion rather than meniscal extrusion

Objective To determine the frequency of medial meniscal extrusion (MME) versus “medial meniscal intrusion” in the setting of bucket handle tears. Images were evaluated for previously reported risk factors for MME, including: medial meniscal root tear, radial tear, degenerative joint disease and joint effusion. Methods Forty-one consecutive cases of bucket handle tear of the medial meniscus were reviewed by consensus by two musculoskeletal radiologists. Imaging was performed using a 1.5 GE Signa MR unit. Patient age, gender, medial meniscal root integrity, MME, medial meniscal intrusion, degenerative joint disease, effusion and anterior cruciate ligament (ACL) tear were recorded. Results Thirteen females and 27 males (age 12–62 years, median=30 years) were affected; one had bucket handle tear of each knee. Effusion was small in 13, moderate in 9 and large in 18. Degenerative joint disease was mild in three, moderate in two and severe in one. 26 ACL tears included three partial and three chronic. Medial meniscal root tear was complete in one case and partial thickness in two. None of the 40 cases with an intact or partially torn medial meniscal root demonstrated MME. MME of 3.1 mm was seen in the only full-thickness medial meniscal root tear, along with chronic ACL tear, moderate degenerative joint disease and large effusion. Medial meniscal intrusion of the central bucket handle fragment into the intercondylar notch was present in all 41 cases. Conclusion Given an intact medial meniscal root in the setting of a “pure” bucket handle tear, there is no MME.     

Effect of gelatin hydrogel incorporating fibroblast growth factor 2 on human meniscal cells in an organ culture model

Efforts to use growth factors to enhance the healing potential of the meniscus have been impeded because their half-lives are too short to maintain the biological activity. The thread was coated with gelatin hydrogel and fibroblast growth factor 2 (FGF 2) was biologically stabilized by incorporating in a gelatin hydrogel-coated thread. The purpose of this study is to investigate the effect of gelatin hydrogel-coated thread incorporating FGF 2 on human meniscal cells in an organ culture. Twenty-five menisci were cut into small pieces, and selected pieces were sutured with gelatin hydrogel-coated thread incorporating FGF 2 (FGF(+) group) or physiologic saline (FGF(−) group), followed by organ culture. The meniscal samples histologically evaluated 4, 7, and 14 days later. The cell density and the number of PCNA-positive cells for the FGF(+) group were higher than those of the FGF(−) group, while the number of TUNEL-positive cells was lower. These results suggest that FGF 2 stimulates the proliferation of meniscal cells and inhibits meniscal cell death. Gelatin hydrogel-coated threads releasable FGF 2 may be useful to promote repairing of human meniscus.     

Parameniscal cyst formation after arthroscopic meniscal repair with biodegradable meniscal arrow: a case report

A 22-year-old male underwent an arthroscopic meniscal repair, using meniscal arrows, due to bucket-handle medial meniscus tear. Magnetic resonance images (MRI) at 3 years revealed a large parameniscal cyst protruding into the extra-capsular popliteal space. Arthroscopic partial cystectomy, removing only the intra-articular portion of the cyst was performed, leaving the extra-articular part of the cyst. Sixteen months postoperatively MRI revealed no cyst remnants, and the patient was free of symptoms.     

Quantitation of polymorphonuclear leukocyte adherence to endothelial cells by electronic particle size discrimination

A method for quantitating the number of polymorphonuclear leukocytes (PMNs) adhering to endothelial cells in vitro is presented. Confluent human umbilical vein endothelial cells cultured in 24-well multiplates and treated with tumor necrosis factor (TNF ) were incubated subsequently wioth PMNs which adhere to the endothelial cell as a function of TNF concentration. Adherent PMNs and endothelial cells were proteolytically dissociated from the multiwell and, using an electronic particle counter, the number of endothelial cells and PMNs were determined simultaneously on the basis of size. The average number of PMNs adhering per endothelial cell was then calculated. The method is rapid and precise and offers an alternative to both tedious microscopic counting and the hazardous radiolabeling of PMNs.     

膝关节半月板损伤的MRI诊断

目的 回顾性研究膝关节半月板不同程度损伤的MRI表现。方法 对手术或临床证实的20例共31个损伤的半月板进行回顾性MRI分析。结果 在20例40个半月板中有31个损伤的半月板，其中单纯内侧损伤4个，单纯外侧损伤3个，两侧半月板同时损伤12例24个。将31个损伤的半月板按Stoller的4级分法分类，其中0级0个，Ⅰ级7个，Ⅱ级11个，Ⅲ级13个。17例出现并发症，其中半月板囊肿1例，内侧副韧带损伤3例，外侧副韧带损伤1例，前后交叉韧带同时损伤2例，内外侧副韧带前后十字交叉韧带同时损伤2例，骨折3例，关节囊积液17例。结论 MRI是一种无创伤性的能准确诊断半月板损伤并进行分级，还能发现多种并发症的成像方法。     

A Strategy of Underexpansion and Ad Hoc Post-Dilation of Balloon-Expandable Transcatheter Aortic Valves in Patients at Risk of Annular Injury: Favorable Mid-Term Outcomes

ObjectivesThe aim of this study was to evaluate a strategy of intentional underexpansion of excessively oversized balloon-expandable transcatheter heart valves (THVs) in terms of clinical outcomes, valve function, and frame durability at 1 year.BackgroundTranscatheter aortic valve replacement requires the selection of an optimally sized THV to ensure paravalvular sealing and fixation without risking annular injury. However, some patients have “borderline” annular dimensions that require choosing between a THV that may be too small or another that may be too large.MethodsWe evaluated 47 patients at risk of annular injury who underwent transcatheter aortic valve replacement (TAVR) with an oversized, but deliberately underexpanded, THV followed by post-dilation if required. Clinical evaluation, echocardiography, and cardiac computed tomography were performed pre-TAVR, post-TAVR, and at 1 year.ResultsDeployment of oversized THVs with modest underfilling of the deployment balloon (<10% by volume) was not associated with significant annular injury. Paravalvular regurgitation was mild or less in 95.7% of patients, with post-dilation required in 10.7%. THV hemodynamic function was excellent and remained stable at 1 year. Computed tomography documented stent frame circularity in 87.5%. Underexpansion was greatest within the intra-annular THV inflow (stent frame area 85.8% of nominal). There was no evidence of stent frame recoil, deformation, or fracture at 1 year.ConclusionsIn carefully selected patients with borderline annulus dimensions and in whom excessive oversizing of a balloon-expandable SAPIEN XT valve (Edwards Lifesciences, Inc., Irvine, California) is a concern, a strategy of deliberate underexpansion, with ad hoc post-dilation, if necessary, may reduce the risk of annular injury without compromising valve performance.     

Biomechanical performance of a collagen meniscus implant with regard to suture material and irrigation fluid

Background

The role of meniscus scaffolds remains controversial as failure rates remain high. The aim of this study was to evaluate the pullout strength of different suture materials used for fixation of the Collagen Meniscus Implant (CMI) regarding different suture materials, and type or temperature of irrigation fluid.