Assessing the biomechanical properties of nitinol staples in normal, osteopenic and osteoporotic bone models: A finite element analysis.

Objective: Bone staples are internal fixation devices that are frequently used in the foot, ankle, and hand to provide stabilization. Fixation stability is vital after fusion or fracture surgeries to ensure proper bone healing. Patients undergoing surgeries that require fixation to keep bones aligned and stable may present with diminishing bone mechanical properties, and this may compromise the ability of the fixation hardware to maintain a stable construct.

Soft-Tissue Tumors: A Pictorial- and Case-Based Guide to Diagnosis and Management.

General orthopaedic surgeons must learn how to appropriately evaluate patients with soft-tissue masses who present at their office. Although the incidence of benign soft-tissue sarcomas substantially outnumbers that of malignant soft-tissue sarcomas, the mismanagement of soft-tissue tumors markedly increases a patient's morbidity. The appropriate use of imaging modalities helps general orthopaedic surgeons accurately diagnose a soft-tissue mass, initiate appropriate management of a soft-tissue mass, and gain a better understanding of which patients with soft-tissue lesions should be referred to an orthopaedic oncologist.

Malakoplakia of Bone: A Case Report and Review of the Literature.

Case: A sixty-one-year-old woman presented with right knee pain. Imaging demonstrated osteonecrosis, pathologic fracture, and a permeative lesion. A biopsy with irrigation and debridement was performed.

Allograft cortical strut for reconstruction of space-occupying bone lesions.

Space-occupying bone lesions present orthopedic surgeons with clinical and operative challenges. Multiple reconstructive procedures have proven successful for small bone lesions but lack the structural support necessary for reconstruction of larger lesions. This study reports the clinical outcomes of patients undergoing excision and reconstruction of large bone lesions with allograft cortical struts without additional internal fixation.

Maximizing phenotype constraint and extracellular matrix production in primary human chondrocytes using arginine-glycine-aspartate concentration gradient hydrogels.

New systematic approaches are necessary to determine and optimize the chemical and mechanical scaffold properties for hyaline cartilage generation using the limited cell numbers obtained from primary human sources. Peptide functionalized hydrogels possessing continuous variations in physico-chemical properties are an efficient three-dimensional platform for studying several properties simultaneously. Herein, we describe a polyethylene glycol dimethacrylate (PEGDM) hydrogel system possessing a gradient of arginine-glycine-aspartic acid peptide (RGD) concentrations from 0mM to 10mM.

Primary human chondrocyte extracellular matrix formation and phenotype maintenance using RGD-derivatized PEGDM hydrogels possessing a continuous Young's modulus gradient.

Efficient ex vivo methods for expanding primary human chondrocytes while maintaining the phenotype is critical to advancing the sourcing of autologous cells for tissue engineering applications. While there has been significant research reported in the literature, systematic approaches are necessary to determine and optimize the chemical and mechanical scaffold properties for hyaline cartilage generation using limited cell numbers. Functionalized hydrogels possessing continuous variations in physico-chemical properties are, therefore, an efficient three-dimensional platform for studying several properties simultaneously.

ECM production of primary human and bovine chondrocytes in hybrid PEG hydrogels containing type I collagen and hyaluronic acid.

The development of advanced materials that facilitate hyaline cartilage formation and regeneration in aging populations is imperative. Critical to the success of this endeavor is the optimization of ECM production from clinically relevant cells. However, much of the current literature focuses on the investigation of primary bovine chondrocytes from young calves, which differ significantly than osteoarthritic cells from human sources.

Potential for thermal damage to articular cartilage by PMMA reconstruction of a bone cavity following tumor excision: A finite element study.

Benign, giant cell tumors are often treated by intralesional excision and reconstruction with polymethylmethacrylate (PMMA) bone cement. The exothermic reaction of the in-situ polymerizing PMMA is believed to beneficially kill remaining tumor cells. However, at issue is the extent of this necrotic effect into the surrounding normal bone and the adjacent articular cartilage.

Bacterial Pyomyositis.

Bacterial pyomyositis has been defined as a subacute, deep bacterial infection of the soft tissues. The entity was originally described only in tropical climates, but it is increasing in incidence in temperate climates, such as in the United States. This is mainly attributed to the presence of immunocompromising states such as HIV/AIDS or liver disease.

Enchondroma and chondrosarcoma of bone: clinical, radiologic, and histologic differentiation.

Intraosseous cartilage tumors are commonly encountered by orthopaedic surgeons during evaluation of a patient for undetermined pain; however, the possibility of missing a malignancy during examination is cause for concern. Surgery for enchondromas is not generally necessary but when clinical and radiographic features suggest a potential chondrosarcoma, prompt referral is necessary. Chondrosarcoma almost always occurs in adults.

Osteochondritis dissecans involving the trochlea: report of two patients (three elbows) and review of the literature.

Osteochondritis dissecans (OCD) is an idiopathic lesion of subchondral bone resulting in separation of the articular cartilage and subchondral bone. Osteochondritis of the elbow primarily involves the capitellum. Only two cases involving the trochlea have been reported, one in the English literature and one in the German literature.