Richard L. McGough

Preoperative Screening/Decolonization for Staphylococcus aureus to Prevent Orthopedic Surgical Site Infection Prospective Cohort Study With 2-Year Follow-Up

We quantified surgical site infections (SSIs) after preoperative screening/selective decolonization before elective total joint arthroplasty (TJA) with 2-year follow-up and 2 controls. Concurrent controls (n = 2284) were patients of surgeons not participating in screening/decolonization. Preintervention controls (n = 741) were patients of participating surgeons who underwent TJA the previous year. Staphylococcus aureus nasal carriers (321/1285 [25%]) used intranasal mupirocin and chlorhexidine baths as outpatients. Staphylococcal SSIs occurred in no intervention patients (0/321) and 19 concurrent controls. If all SSIs occurred in carriers and 25% of controls were carriers, staphylococcal SSI rate would have been 3.3% in controls (19/571; P = .001). Overall SSI rate decreased from 2.7% (20/741) in preintervention controls to 1.2% (17/1440) in intervention patients (P = .009). Preoperative screening/selective decolonization was associated with fewer SSIs after elective TJA.

VEGF and BMP expression in mouse osteosarcoma cells.

Osteosarcoma is the most common primary bone malignancy. Despite improvements in therapy, approximately 30% of patients experience pulmonary metastasis. Expression of several growth factors, including VEGF and BMPs, has been implicated in tumor progression and metastatic potential. We hypothesized increased metastatic potential of mouse osteosarcoma cells positively correlates with the expression of VEGF and BMPs. We studied the expression patterns of these growth factors in two murine osteosarcoma cell lines with varying degrees of metastatic potential: K7M2 (highly metastatic) and K12 (minimally metastatic). Expression of VEGF and BMP2 were higher in the metastatic K7M2 cell line. We also investigated the effects of the BMP antagonist noggin on osteosarcoma growth characteristics in vitro. We noted decreased motility, altered morphology, and increased cell death in the highly metastatic K7M2 cell line. Less metastatic K12 cells showed substantial cell death without clear alteration of motility or morphology. These data suggest BMP2 expression may be an important factor in osteosarcoma metastasis and noggin administration theoretically could block its actions. Inhibition of BMPs and VEGF should be investigated further as a possible strategy for decreasing the incidence of pulmonary metastases in osteosarcoma.

Angiogenic cytokines in cartilage tumors.

Pathologic neovascularization has been described in numerous types of cancers. The angiogenic cytokines vascular endothelial growth factor and basic fibroblast growth factor are thought to be the primary inducers of angiogenesis in these tumors. Hypoxia-inducible transcription factor is a nuclear transcription factor that promotes vascular endothelial growth factor expression. Prior studies have shown pathologic neovascularization in chondrosarcoma, which correlates with pathologic grade of the tumor. Angiogenic and nonangiogenic cartilage tumors were studied for expression of vascular endothelial growth factor, basic fibroblast growth factor and hypoxia-inducible transcription factors by immunohistochemistry and Northern blot analysis. Expression of vascular endothelial growth factor and hypoxia-inducible transcription factor were increased significantly in angiogenic tumors. Fibroblast growth factor expression was similar in angiogenic and nonangiogenic specimens. This may have implications for tumor grading and surgical decision-making, and potential treatment with antiangiogenesis chemotherapeutic agents.

Pathologic neovascularization in cartilage tumors

Tumor-induced angiogenesis is necessary to sustain radial growth of tumors. Increased microvascularity has been correlated with increased metastatic potential in breast, gastrointestinal, and gynecologic tumors, but has not been well studied in cartilaginous tumors. Grade II and Grade III chondrosarcomas have increased metastatic potential compared with Grade I tumors. One reason for this may be pathologic neovascularization. The purpose of the current study was to quantify the microvessel density of cartilage tumors. Seven Grade III, 17 Grade II, and eight Grade I chondrosarcomas, and 22 benign cartilage tumors were examined. Specimens were stained with antiCD34 antibody. Microvessel densities then were determined by direct counting and estimated using the Chalkley technique. Microvessel densities for Grade III and Grade II chondrosarcomas were 45.9 and 46.2 per high-power field and for Grade I and benign tumors the microvessel densities were 9.3 and 10.3. Microvessel densities of the aggressive tumors (Grades III and II) were greater than the microvessel densities of the nonaggressive tumors (Grade I and benign). Chalkley estimates confirmed the results. Microvascularity in cartilage tumors correlates with their biologic aggressiveness and seems promising as a variable to help with histopathologic grading and as a target for new treatment modalities.

Primary versus secondary distal femoral arthroplasty for treatment of total knee arthroplasty periprosthetic femur fractures.

Current methods of fixing periprosthetic fractures after total knee arthroplasty (TKA) are variable, and include open reduction and internal fixation (ORIF) via plating, retrograde nailing, or revision using standard revision TKA components or a distal femoral arthroplasty (DFA). The purpose of this study is to compare patients who failed plating techniques requiring subsequent revision to DFA to patients who underwent primary DFA. Of the 13 patients (9.2%) who failed primary ORIF, causes included nonunion (53.8%), infection (30.8%), loosening (7.7%), and refracture (7.7%). There were significantly more surgical procedures for ORIF revision to DFA compared to primary DFA. Complications for patients who underwent primary reconstruction with DFAs included extensor mechanism disruption (8.3%), infection (5.6%), and dislocation (2.8%). Primary reconstruction via ORIF is beneficial for preserving bone stock, but primary DFA may be preferred in osteopenic patients, or those at high risk for nonunion.

Chondromyxoid fibroma of rib with a novel chromosomal translocation: a report of four additional cases at unusual sites

BackgroundChondromyxoid fibromas (CMFs) are rare benign chondroid/myxoid matrix-producing tumors that occur in metaphyses of long tubular bones, and very rarely in small bones of hands and feet. Flat bone involvement is even more uncommon. Prior cytogenetic analyses have identified complex abnormalities involving chromosome 6 in the majority of cases.MethodsA search for CMF over an 8-year period (1999–2006) from the surgical pathology files of our institution yielded 16 cases. Four cases occurred in relatively unusual regions, three from the small bones of distal extremities and one from the rib. The rib lesion wassubmitted forroutinecytogenetic analysis.ResultsRadiographic studies revealed that all four lesions were well-defined expansile radiolucent lesions which expanded the bony cortices with lobulated margins, sclerotic rim, septation, and no calcification. Morphologically, all four lesions showed typical features of CMF and had low proliferative index with Ki-67. Cytogenetic analysis on the rib lesion revealed a novel chromosomal translocation, t(1;5)(p13;p13). None of the four patients had a recurrence after a mean duration of follow-up of 24 months.ConclusionCMF originating in unusual locations should be distinguished from chondrosarcomas, especially on small biopsies, and should be included in the differential diagnosis. As previously noted in the literature, the cells can be positive for actin but unlike conventional chondroid neoplasms can be negative for S-100. To our knowledge, this is the first report describing a novel chromosomal translocation, t(1;5)(p13;p13) in CMF.

Malignant granular cell tumor of the ulnar nerve with novel cytogenetic and molecular genetic findings

We report an unusual case of ulnar nerve-based malignant granular cell tumor characterized by gains of chromosome 10 and loss of P16 detected by conventional karyotyping and by fluorescence in situ hybridization, respectively, in a 74-year-old male. To our knowledge, these findings have never been reported previously in malignant granular cell tumors.

Clinical outcome of osseointegrated prostheses for lower extremity amputations: a systematic review of the literature

Background:Extremity amputation is a common procedure for a variety of indications, including vascular problems, tumors, infections, and traumatic events. The socket prosthesis has always been the standard but has a low patient satisfaction and high skin complication rate. The aim of the present study was to evaluate the outcome of osseointegrated prostheses (those that eliminate the socket in favor of direct skeletal attachment) for lower extremity amputees. Methods:A systematic review of the literature was performed using MEDLINE (January 1946–May 2014), EMBASE (Jan 1980–May 2014), and SCOPUS (Jan 1996–May 2014). All studies evaluating the clinical outcome of an osseointegrated prosthesis for patients with a lower extremity amputation were included. All included studies were evaluated for methodological quality using the GRADE checklist. Results:Thirteen studies with a total of 540 subjects were included. Between 82–90% of patients used their prosthesis on a daily basis. Ninety-five percent of patients were happy with their osseointegrated prosthesis. Short Form (SF)-36 and Questionnaire for Persons with Transfemoral Amputation (Q-TFA) scores were satisfactory. There was a high complication rate, including skin problems (30–54%), skin infections (28–55%), implant infections (2–41%), loosening (2–6%), periprosthetic fracture (0–9%), revision surgery (8–67%), and explants (3–20%). Most of the included studies had more than one flaw in their study design, decreasing their methodological quality. Meta-analysis of the data was not possible due to publication bias. Conclusions:This systematic review showed that osseointegrated prostheses resulted in a good quality of life and patient-reported outcomes. However, skin problems and infections were common and patients often needed revision surgery.

Angiomyomatous hamartoma of a popliteal lymph node: an unusual cause of posterior knee pain.

Angiomyomatous hamartoma is a primary vascular tumor primarily found in the inguinal and femoral lymph nodes characterized by the replacement of nodal tissue by smooth muscle cells and fibrous tissue in sclerotic lymphatic stroma. There has been 1 report of an angiomyomatous hamartoma of a cervical lymph node, and this is the first reported case occurring in an extremity. We present a case of angiomyomatous hamartoma occurring in a single popliteal lymph node.

Metastatic mixed tumor arising in bone. A case report and review of the literature.

Mixed tumors, or pleomorphic adenomas, are the most common benign tumors of the salivary gland1. Minsen2 first described them in 1874 as heterogeneous tumors of the parotid gland containing both mesenchymal and epithelial features3. An entity known as benign metastasizing mixed tumor has also been described4,5. It occurs when a histologically benign mixed tumor metastasizes to other sites, such as soft tissue, the liver, and bone4-7. Rarely, malignant mixed tumors arise in extrasalivary locations, including bone4,8. We know of one case report in which a mixed tumor with malignant characteristics arose in bone and metastasized to the lungs9. We report the first case that we are aware of in which a histologically benign mixed tumor arising in bone metastasized to the lungs. Histologic examination of the metastatic lesion revealed tissue identical to the primary lesion, with no evidence of malignant degeneration. A forty-two-year-old woman presented in 1995 with a left pretibial mass. No systemic symptoms were noted at that time. Radiographs revealed a lytic lesion in the proximal part of the tibia (Fig. 1-A). A computed tomographic scan demonstrated the lytic lesion eroding the anterior tibial cortex, with no internal characteristics (Fig. 1-B). A bone scan showed increased activity in the proximal part of the tibia and no other osseous lesions (Fig. 1-C). Open biopsy was performed, followed by curettage and packing with methylmethacrylate (Fig. 1-D). Pathologic examination revealed a mixed tumor with an entirely benign histologic appearance, and consultation with two bone pathologists confirmed the benign nature of the lesion. Evaluation of the head and neck for evidence of a primary tumor consisted of a computed tomographic scan of the neck, direct laryngoscopy, and examination by an otolaryngologist. There was …