Purpose:The aim of this study was to compare the effectiveness of 2 different meniscal scaffolds in treating patients with irreparable partial medial meniscal tear and patients complaining of pain in the medial compartment of the knee due to a previous partial medial meniscectomy. Based on previous studies, we hypothesized that both the scaffolds are effective in improving clinical outcomes in these patient populations.Material and Methods:Twenty-eight patients underwent collagen-based medial meniscus implantation (CMI-Menaflex) and 25 with a second-generation scaffold (Actifit). All patients were assessed with Lysholm, Tegner scale, and MRI evaluation—preoperatively, at 6 months, at 12 moths, and followed-up for a minimum of 2 years. Second look arthroscopy and concomitant biopsy were performed in 7 and 12 patients of CMI and Actifit groups, respectively.Results:The CMI group at final follow-up showed improvement in Lysholm score from 58.4 ± 17.3 to 94.5 ± 6.0, while the Actifit group showed improvement from 67.0 ± 15.7 to 90.3 ± 13.1; the improvement was statistically significant in both the groups but intergroup difference was not statistically significant (P = 0.1061). Tegner Activity Scale score improved in both the groups, but intergroup difference was not statistically significant (P = 0.5918). MRI evaluation showed in situ scaffold and no progression of degenerative arthritis in both the groups at final follow-up. Histological evaluation showed more fibrous tissue with blood vessels in the CMI group and the Actift group showed avascular cartilaginous features.Conclusion:Both the scaffolds are effective in improving patients’ symptoms and joint function at short-term follow-up.

Background:Trabecular Metal (TM) is a new highly porous material made of tantalum (Zimmer, Warsaw, Indiana, USA). Its three-dimensional structure is composed of a series of interconnected dodecahedron pores that are on average 550 μm in diameter. This size is considered optimal for bone ingrowth and is similar to trabecular bone. The elastic modulus of TM (3 GPa) is more similar to that of cancellous (0,1-1,5 GPa) or cortical (112-18 GPa) bone and is significantly less similar to that of Titanium (110 GPa) and Co-Cr alloys (220 GPa). These features enable bone apposition and remodeling. The purpose of the present study was to evaluate the histology of the bone-implant interface in a human specimen.Materials and Methods:A highly porous tantalum cup (Zimmer, Warsaw, Indiana, USA) was removed for recurrent dislocations three years after implantation. In order to obtain a slice of the cup, two cuts were made on the centre using an Exakt cutting machine. Then the slice was embedded in a Technovit resin and a Hematoxylin-eosin stain was used to study the bone tissue. Bone ingrowth was calculated using a method based on simple calculations of planar geometry.Results:The histological evaluation of the periprosthetic tissues revealed a typical chronic inflammation with few particles of polyethylene that were birefringent using polarized light. The quantitative evaluation of bone ingrowth revealed that more than 95% of voids were filled with bone.Discussion:In the literature, a lot of studies focused on tantalum were carried on animal model. Up to now little information is available about the histology of the bone-tantalum interface in a human artificial joint. We had an opportunity to remove a well integrated cup hence this study. The histology confirmed the strong relationship between the structure of this material and bone. The morphometric analysis revealed a high percentage of bone ingrowth.

The skeleton of the batoid fish consists of a mixture of calcified and uncalcified cartilage with a typical layout of mineral deposition toward the outer border, leaving an uncalcified central core in most of the skeleton segments. An exception is observed in the radials, where mineral deposition is central. Joints and endoskeleton segments were studied in two adult samples of Raja cf. polystigma. Histomorphology, mineral deposition pattern, and zonal chondrocyte duplication activity were compared among several endoskeleton segments, but with particular attention to the fin rays; in the first, the uncalcified cartilage is central with an outer layer ranging from mineralized tesserae to a continuous calcified coating, whereas in the second, the uncalcified cartilage surrounds one or more central calcified columns. The diarthroses have a joint cavity closed by a fibrous capsule and the sliding surfaces rest on the base of mineralized tesserae, whereas the interradial amphiarthroses show a layer of densely packed chondrocytes between the flat, calcified discs forming the base of neighboring radials. In the endoskeleton segments, three types of tesserae are distinguished, characterizing the phases of skeletal growth and mineralization which present differences in each endoskeleton segment. The chondrocyte density between central core, subtesseral layer, and radial external cartilage did not show significant differences, while there was a significant difference in chondrocyte density between the latter zones and the type c tesserae of the pelvic girdle. The histomorphology and morphometry observed in Raja cf. polystigma suggest a model of cartilage growth associated with structural stiffening without remodeling. A key point of this model is suggested to be the incomplete mineralization of the tesseral layer and the continuous growth of cartilage, both enabling fluid diffusion through the matrix fibril network of scattered, uncalcified cartilage zones inside and between the tesserae.

The relationship between cartilage growth – mineralization patterns were studied in adult Rajidae with X‐ray morphology/morphometry, undecalcified resin‐embedded, heat‐deproteinated histology and scanning electron microscopy. Morphometry of the wing‐fins, nine central rays of the youngest and oldest specimens documented a significant decrement of radials mean length between inner, middle and outer zones, but without a regular progression along the ray. This suggests that single radial length growth is regulated in such a way to align inter‐radial joints parallel to the wing metapterygia curvature. Trans‐illumination and heat‐deproteination techniques showed polygonal and cylindrical morphotypes of tesserae, whose aligned pattern ranged from mono‐columnar, bi‐columnar, and multi‐columnar up to the crustal‐like layout. Histology of tessellated cartilage allowed to identify of zones of the incoming mineral deposition characterized by enhanced duplication rate of chondrocytes with the formation of isogenic groups, whose morphology and topography suggested a relationship with the impending formation of the radials calcified column. The morphotype and layout of radial tesserae were related to mechanical demands (stiffening) and the size/mass of the radial cartilage body. The cartilage calcification pattern of the batoids model shares several morphological features with tetrapods' endochondral ossification, that is, (chondrocytes' high duplication rate, alignment in rows, increased volume of chondrocyte lacunae), but without the typical geometry of the metaphyseal growth plates. Research Highlights 1. The wing‐fins system consists of stiff radials, mobile inter‐radial joints and a flat inter‐radial membrane adapted to the mechanical demand of wing wave movement. 2. Growth occurs by forming a mixed calcified‐uncalcified cartilage texture, developing intrinsic tensional stresses documented by morphoanatomical data.

This study aims at presenting a case of symmetrical and bilateral thinning observed in a skull belonging to the skeleton of a mature woman from the medieval cemetery of Caravate (north Italy). Macroscopical, radiological, and histological analyses were performed to investigate the condition. The analyses allowed us to detect a progressive loss of both the outer table and the diploe, and the sparing of the inner table. As a controversial condition in the clinical and paleopathological literature, this case poses some difficulties in discussing the differential diagnosis. However, the sex determination, estimation of the age-at-death and different characteristics observed at the level of the postcranial bones, in particular the fractures recorded on different vertebral bodies, allowed us to correlate the biparietal thinning found in this subject to ageing and osteoporosis.