Antonio Mazzotti

Current concepts in the biopsy of musculoskeletal tumors: AAOS exhibit selection.

BACKGROUND A musculoskeletal tumor biopsy can involve fine needle aspiration, core needle biopsy, or incisional biopsy. Controversy regarding the diagnostic yield of these biopsy techniques continues. The purpose of this article is to summarize the current concepts in the biopsy of musculoskeletal tumors. METHODS We performed a literature review of clinical articles reporting on the biopsy of bone and soft-tissue primary tumors. Clinical articles were excluded on the basis on abstract content if they represented case reports, review or opinion articles, or technique descriptions. Eighteen of the thirty-nine articles that remained were excluded because the results did not indicate the diagnostic accuracy of the various biopsy techniques. Thus, twenty-one articles with diagnostic data on the biopsy of bone and soft-tissue tumors were included in this review. RESULTS Core needle biopsy appeared to be more accurate than fine needle aspiration, and incisional biopsy appeared to be more accurate than both of these techniques, but the differences did not reach significance. Incisional biopsy was more expensive than the percutaneous biopsy methods. In deep musculoskeletal tumors, incorporation of ultrasonography or computed tomography for guidance is easy and safe and can be useful for increasing the accuracy of the biopsy. Advantages of a percutaneous technique compared with an incisional one are the low risk of contamination and the minimally invasive nature. Certain anatomic locations and histologic types were associated with diagnostic difficulty. Vertebral tumors had the lowest diagnostic accuracy regardless of the biopsy technique. Myxoid, infection, and round cell histologies were associated with the lowest diagnostic accuracy. CONCLUSIONS The current literature has not clarified the optimal biopsy technique for the diagnosis of bone and soft-tissue tumors. However, core needle biopsy is usually preferable to incisional biopsy because of the low risk of contamination and the low cost. In addition, the use of imaging guidance increases the diagnostic accuracy of musculoskeletal biopsies and reduces the risk of complications. If the result of a percutaneous biopsy is nondiagnostic, a small incisional biopsy should be performed. LEVEL OF EVIDENCE Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Atypical femoral fractures.

Bisphosphonates (BPs) represent the most widely used therapy for osteoporosis. Recently, a relationship between long-term treatment with BPs and a subset of atypical femoral fractures (AFFs) from below the lesser trochanter to the sovracondilar line has been described. Many etiopathogenetic theories have been invoked to explain AFFs: reduced bone turnover and increased osteoblast bone apposition with accumulation of microdamage and decreased bone toughness with subsequent increased risk of micro-cracks and duration fractures, collagen fiber cross-linking and vascularization impairment. Based on published studies, a task force of the American Society for Bone and Mineral Research has redacted the diagnostic criteria of AFFs by classifying them according to their major and minor criteria. The treatment for displaced AFFs is osteosynthesis, but there is a lack of evidence for undisplaced AFFs and the duration of fracture treatment. BPs have a proven efficacy in osteoporotic fracture reduction as well as in the treatment of other bone diseases caused by the downregulation of osteoclast activity. BPs have an excellent benefit-to-risk ratio; however, minor adverse events, such as AFFs, occur in a variable percentage of patients treated over a long period of time.

Surgical Treatment of Cavus Foot in Charcot-Marie-Tooth Disease: A Review of Twenty-four Cases

Charcot-Marie-Tooth disease is the single most common diagnosis associated with cavus foot. The imbalance involving intrinsic and extrinsic muscles has been suggested as the main pathogenetic cause of cavus foot in this disease. The goal of surgical treatment is to correct the deformity to obtain a plantigrade foot. In the presence of a flexible deformity and the absence of degenerative arthritis, preserving as much as possible of the overall range of motion of the foot and ankle is advisable. Twenty-four cavus feet in twelve patients with Charcot-Marie-Tooth disease were included in the study. Clinical evaluation was summarized with the Maryland Foot Score. Radiographic evaluation assessed calcaneal pitch, Meary angle, Hibb angle, and absence of degenerative joint changes. Only patients who had a flexible deformity, with varus of the heel reducible in the Coleman-Andreasi test, and did not have degenerative joint arthritis were included in this study. Surgical treatment consisted in plantar fasciotomy, midtarsal osteotomy, extensor hallucis longus tendon transfer to the first metatarsal (Jones procedure), and dorsiflexion osteotomy of the first metatarsal. Mean follow-up was six years (range, two to thirteen years). The mean Maryland Foot Score was 72 preoperatively and 86 postoperatively. The postoperative result was rated as excellent in twelve feet (50%), good in ten (42%), and fair in two (8%). Mean calcaneal pitch was 34° preoperatively and 24° at the time of the latest follow-up, the mean Hibb angle was 121° preoperatively and 136° postoperatively, and the mean Meary angle was 25° preoperatively and 2° postoperatively. Plantar fasciotomy, midtarsal osteotomy, the Jones procedure, and dorsiflexion osteotomy of the first metatarsal yielded adequate correction of flexible cavus feet in patients with Charcot-Marie-Tooth disease in the absence of fixed hindfoot deformity. The fact that the improvement in the outcome score was only modest may be attributable to the lack of motor balance.

Pedicle screw insertion techniques: an update and review of the literature.

Pedicle screw construct have become one of the most practiced procedure in spinal surgery. Despite commonly used, questions remain about their safety especially for the thoracic spine and in deformity where difficulty in positioning can lead to pedicle breach and adjacent structures injury. Misplacement rates have been reported to be from 5 to 41% in the lumbar spine and from 3 to 55% in the thoracic spine. Hence, various procedures have been described in order to improve pedicle screw insertion accuracy. Aim of this study is to evaluate current concepts on pedicle screws placement techniques to better understand recent attitude and clarify some doubts when selecting the most proper method.

Chondrogenic differentiation of human adipose mesenchimal stem cells: Influence of a biomimetic gelatin genipin crosslinked porous scaffold

Human adipose derived stem cells have shown chondrogenic differentiation potential in cartilage tissue engineering in combination with biomimetic materials. In this study, the chondrogenic potential of a porous gelatin based scaffold genipin (GNP) crosslinked was investigated in human mesenchymal stem cells obtained from adipose tissue. Cells were cultured up to 4 weeks on the scaffold and on monolayer, MTT assay was performed to evaluate cell viability, light, and transmission electron microscopy were carried out to demonstrate cell proliferation, scaffold adhesion, and cell colonization inside the porous architecture of the biomaterial. The expression of chondrogenic markers such as SOX9, collagen type II, aggregan, and versican was investigated by Real Time PCR. Results showed an high cell viability, adhesion, and colonization of the scaffold. Real Time PCR data demonstrated an upregulation of all the chondrogenic markers analyzed. In conclusion, 3D gelatin GNP crosslinked porous scaffold provides an improved environment for chondrogenic differentiation of stem cells compared with cell monolayer culture system. Microsc. Res. Tech. 77:928–934, 2014.

In vitro osteogenic and odontogenic differentiation of human dental pulp stem cells seeded on carboxymethyl cellulose-hydroxyapatite hybrid hydrogel

Stem cells from human dental pulp have been considered as an alternative source of adult stem cells in tissue engineering because of their potential to differentiate into multiple cell lineages. Recently, polysaccharide based hydrogels have become especially attractive as matrices for the repair and regeneration of a wide variety of tissues and organs. The incorporation of inorganic minerals as hydroxyapatite nanoparticles can modulate the performance of the scaffolds with potential applications in tissue engineering. The aim of this study was to verify the osteogenic and odontogenic differentiation of dental pulp stem cells (DPSCs) cultured on a carboxymethyl cellulose—hydroxyapatite hybrid hydrogel. Human DPSCs were seeded on carboxymethyl cellulose—hydroxyapatite hybrid hydrogel and on carboxymethyl cellulose hydrogel for 1, 3, 5, 7, 14, and 21 days. Cell viability assay and ultramorphological analysis were carried out to evaluate biocompatibility and cell adhesion. Real Time PCR was carried out to demonstrate the expression of osteogenic and odontogenic markers. Results showed a good adhesion and viability in cells cultured on carboxymethyl cellulose—hydroxyapatite hybrid hydrogel, while a low adhesion and viability was observed in cells cultured on carboxymethyl cellulose hydrogel. Real Time PCR data demonstrated a temporal up-regulation of osteogenic and odontogenic markers in dental pulp stem cells cultured on carboxymethyl cellulose—hydroxyapatite hybrid hydrogel. In conclusion, our in vitro data confirms the ability of DPSCs to differentiate toward osteogenic and odontogenic lineages in presence of a carboxymethyl cellulose—hydroxyapatite hybrid hydrogel. Taken together, our results provide evidence that DPSCs and carboxymethyl cellulose—hydroxyapatite hybrid hydrogel could be considered promising candidates for dental pulp complex and periodontal tissue engineering.

Ultrastructural analysis of human bone marrow mesenchymal stem cells during in vitro osteogenesis and chondrogenesis

The main purpose of this article was to describe the morphology of mesenchymal stem cells (MSCs) differentiated in vitro towards osteogenic and chondrogenic lineages and to focus on the ultrastructural features associated with these processes. Human mononuclear cells (hMNC) were isolated, expanded, and analyzed for the expression of specific cell surface markers to demonstrate their stem cell characteristics. Human mononuclear cells were differentiated in vitro in an osteogenic and in a chondrogenic sense for 7, 14, 21, and 28 days. Subsequently, they were processed using electron microscopic analysis (FEISEM). Alizarin red and alcian blue staining were carried out to demonstrate the deposition of mineral salts and proteoglycans in the extracellular matrix. Undifferentiated MSCs showed a cell surface covered by filopodia and ondulopodia. During differentiation, the MSCs changed their shape from a round to a fibroblastic‐like shape. At the end of the differentiation, several filaments with a parallel orientation in the osteogenic samples as well as a network organization in the chondrogenic samples were detected in the extracellular spaces. This study demonstrated that there are morphological features associated with the undifferentiated and differentiated states of the MSCs, which could be utilized as new parameters for identifying and classifying these cells. Microsc. Res. Tech., 2012.

New couplings, old problems: Is there a role for ceramic-on-metal hip arthroplasty?

Ceramic-on-metal (CoM) total hip arthroplasty (THA) theoretically combines both the advantages of ceramic-on-ceramic (CoC) and metal-on-metal (MoM) bearings: negligible rupture risk of the liner with a limited ion release. As primary endpoint, we asked whether serum cobalt, chromium and molybdenum concentrations in 20 CoM-THA patients at an average of 3-years follow-up were higher than those measured in the pre-operative population and correlate with clinical/radiological parameters. As secondary endpoint, we wanted to verify whether ion levels in CoM-THA patients were different from those obtained in a similar cohort of 29 MoM-THA patients at the same average follow-up. Ion values were measured by atomic absorption spectrometry. Functional outcome was assessed with Harris Hip Score and UCLA scale. Presence of radiographic radiolucencies around the implant, and acetabular inclination angle were evaluated. Chromium and cobalt levels in CoM-THA patients were significantly higher (p < 0.001) at 3-years follow-up than before surgery. Molybdenum concentrations were not significantly different (p = 0.45). No signs of implant loosening were recorded. Functional outcome was excellent with HHS and UCLA scale rising from 50 and 3.6 pre-operatively to 90.8 and 6.3, respectively at 3-years follow-up (p < 0.001). Chromium serum levels were significantly lower in CoM-THA than in MoM-THA group (p = 0.02) while cobalt values, even if lower, did not reach statistically significance (p = 0.054). Our results show that CoM-THA patients achieve excellent clinical outcome with a limited chromium release at 3-years follow-up.

Changes in the gene expression of co-cultured human fibroblast cells and osteosarcoma cells: the role of microenvironment

Background The progression of malignant tumors does not depend exclusively on the autonomous properties of cancer cells; it is also influenced by tumor stroma reactivity and is under strict microenvironmental control. By themselves, stromal cells are not malignant, and they maintain normal tissue structure and function. However, through intercellular interactions or by paracrine secretions from cancer cells, normal stromal cells acquire abnormal phenotypes that sustain cancer cell growth and tumor progression. In their dysfunctional state, fibroblast and immune cells produce chemokines and growth factors that stimulate cancer cell growth and invasion. In our previous work, we established an in vitro model based on a monolayer co-culture system of healthy human fibroblasts (HFs) and human osteosarcoma cells (the MG-63 cell line) that simulates the microenvironment of tumor cells and healthy cells. The coexistence between MG-63 cells and HFs allowed us to identify the YKL-40 protein as the main marker for verifying the influence of tumor cells grown in contact with healthy cells. Methods In this study, we evaluated the interactions of HFs and MG-63 cells in a transwell co-culture system over 24 h, 48 h, 72 h, and 96 h. We analyzed the contributions of these populations to the tumor microenvironment during cancer progression, as measured by multiple markers. We examined the effect of siRNA knockdown of YKL-40 by tracking the subsequent changes in gene expression within the co-culture. We validated the expression of several genes, focusing on those involved in cancer cell invasion, inflammatory responses, and angiogenesis: TNF alpha, IL-6, MMP-1, MMP-9, and VEGF. We compared the results to those from a transwell co-culture without the YKL-40 knockdown. Results In a pro-inflammatory environment promoted by TNF alpha and IL-6, siRNA knockdown of YKL-40 caused a down-regulation of VEGF and MMP-1 expression in HFs. Conclusions These findings demonstrated that the tumor microenvironment has an influence on the gene expression of healthy surrounding tissues and on the process of tumorigenicity and it is emerging as attractive targets for therapeutic strategies.

Bioabsorbable Calcaneo-Stop Implant for the Treatment of Flexible Flatfoot: A Retrospective Cohort Study at a Minimum Follow-Up of 4 Years

ABSTRACT Arthroereisis of the subtalar joint is a common surgical technique in Europe for the management of flexible flatfoot in the pediatric population. In most cases, it is performed using a calcaneo‐stop metallic screw. Despite the good clinical results, screw removal is always advised after 2 to 3 years. The use of a bioabsorbable screw might overcome the need for a second operation to remove a nonabsorbable device. We report the results of a biodegradable calcaneo‐stop screw at a minimum of 4 years of follow‐up. Eighty‐eight procedures were performed on 44 children. All patients were clinically and radiologically evaluated preoperatively and at a minimum 4‐year follow‐up period. Patient satisfaction and plantar collapse using Viladots classification were recorded. Mearys talus–first metatarsal angle and talocalcaneal angle were measured on radiographs preoperatively and at the last follow‐up visit. The presence of the device at the last follow‐up examination was assessed by magnetic resonance imaging. The mean follow‐up duration was 56 months. Of the 44 patients, 33 (75%) reported excellent clinical outcomes, 9 (20.5%) good outcomes, and 2 (4.5%) poor. Foot print improvement was registered for all patients. The mean Mearys talus–first metatarsal angle had improved from 160.6° ± 7.7° preoperatively to 170.6° ± 6.5° at the last follow‐up visit (p < .001). The talocalcaneal angle had decreased from 39.9° ± 5.2° preoperatively to 29.4° ± 4° at the last follow‐up examination (p < .001). At the 4‐year follow‐up point, the implant could be seen to have almost completely biodegraded on magnetic resonance imaging. Two screw breakages occurred. The bioabsorbable calcaneo‐stop screw seems to be an effective solution for flexible flatfoot in pediatric patients. Also, owing to its biodegradable composition, the need of a second operation for implant removal will not always be necessary. &NA; Level of Clinical Evidence: 4