This meta-analysis found no evidence that using patient-specific cutting blocks provides superior accuracy to using manual instrumentation during TKA.

The biomechanical properties of each potential ALL graft can be factored in when deciding which type of graft to use.

ORTHOUNION is a multicentre, open, comparative, three-arm, randomized clinical trial (EudraCT number 2015-000431-32) to compare the efficacy, at one and two years, of autologous human bone marrow-derived expanded mesenchymal stromal cell (hBM-MSC) treatments versus iliac crest autograft (ICA) to enhance bone healing in patients with diaphyseal and/or metaphysodiaphyseal fracture (femur, tibia, and humerus) status of atrophic or oligotrophic nonunion (more than 9 months after the acute fracture, including recalcitrant cases after failed treatments). The primary objective is to determine if the treatment with hBM-MSCs combined with biomaterial is superior to ICA in obtaining bone healing. If confirmed, a secondary objective is set to determine if the dose of 100 × 106 hBM-MSCs is noninferior to that of 200 × 106 hBM-MSCs. The participants (n = 108) will be randomly assigned to either the experimental low dose (n = 36), the experimental high dose (n = 36), or the comparator arm (n = 36) using a central randomization service. The trial will be conducted in 20 clinical centres in Spain, France, Germany, and Italy under the same clinical protocol. The confirmation of superiority for the proposed ATMP in nonunions may foster the future of bone regenerative medicine in this indication. On the contrary, absence of superiority may underline its limitations in clinical use.

Homeostasis of the intervertebral disc relies on nutrient supply and waste clearance through the dense capillary network that is in contact with the cartilage endplate (CEP). We developed a micro-computerized tomography (micro-CT) method to quantify the marrow contact channel surface (MCCS) with the CEP and to validate the hypothesis according to which MCCS was correlated to the effective permeability of the vertebral endplate (VEP) and influenced by the mechanical stimuli. The influence of compression loading on local vascularization was investigated. Six 4-week-old skeletally immature pigs were instrumented with left pedicle screws and rod at both T5-T6 and L1-L2 levels to create asymmetrical spine tethers. After 3 months of growth, three cylindrical specimens of the VEP (one central and two lateral right and left) were obtained from both the instrumented and the control levels. We used a previously validated method for measuring permeability. Micro-CT analysis (resolution 12 mm) yielded a gray-scale 2D-image of the discal end of each specimen converted into a binary 2D-image to derive the MCCS. Correlations between MCCS and effective permeability were assessed. Effective permeability and MCCS were significantly decreased compared to the control group especially on the tethered side (À41.5%, p ¼ 0.004 and À52.5%, p ¼ 0.0009, respectively). Correlations were significant and showed maximal value (r 2 ¼ 0.430, p < 0.0001) on the tethered side involving maximal compressive loadings. Mechanical stimuli, due to unbalanced growth, altered the vascularization and the convective properties of the CEP. The cascade of mechanobiological events should offer perspectives for research on disc degeneration and attempted treatment. Keywords: vertebral endplate; permeability; vascular network; spine; micro-CT scan Solutes are transported to and from the intervertebral disc (IVD) by passive diffusion and mostly by an active convection mechanism. The latter mainly takes place through the cartilage endplate (CEP) of the vertebral endplate (VEP).1 Nutrients' transport is facilitated by the presence of a complex vascular network.2,3 Vascular buds are in direct contact with the CEP through marrow contact channels crossing the calcified layer of the VEP 4,5 which represents a barrier to solute transport. 4,6 There is a link between permeability and vascular supply as permeability is greater in the center of the VEP [6][7][8] where vascular network is the more dense.3,4,6 Oki et al. 9 have shown that the density of the vascular buds does not vary significantly between the region of the CEP facing the annulus and the one facing the nucleus pulposus. However, they demonstrated some morphologic differences: vascular buds in the annulus region form simple loops whereas those facing the nucleus pulposus are organized in complex multiple loop networks. This latter morphology allows a greater capillary contact surface in the center of the VEP than in the periphery thus facilitating solutes transport in the center. Benneker et al. 5...

The biomechanical properties of a four-strand gracilis construct are comparable to the ones of standard grafts. This type of graft would be useful in the reconstruction of the anteromedial bundle in patients with partial ACL ruptures.