Three-dimensional printing and modeling has evolved significantly since first introduced in the 1980s. In the last 5 years, this revolution in technology has become far more accessible and affordable, and is already mainstream in many areas of medicine. Nowhere is this more apparent than in orthopedics, and many surgeons already incorporate aspects of 3D modeling and virtual procedures in their routine clinical practice. However, this technology promises to become even more prevalent as creative applications continue to be developed, and further innovations are certain to come. There are important public policy aspects to consider, both economic and regulatory. Regulatory issues are currently still under development, but will need to take into account sterilization, quality assurance, and product liability. The mechanical integrity of 3D-printed implants is influenced by the unique characteristics of the print process, including the energy density of the laser, the resolution of the print, and the orientation of the print on the build platform. Introduction of expensive new technology should only be done after careful consideration of the costs associated, the potential benefits, and the value that can be derived. The value in 3D modeling and printing can be considered relative to the initial costs, the experience of a 3D modeling unit, the complexity of a particular case, and the clinical expertise of the surgeons involved. There is significant potential value derived from modeling most displaced intra-articular fractures, once a 3D modeling unit is established and proficient. However, the greatest value comes from modeling the most highly complex cases. When the pathology is most abnormal, 3D modeling/printing can be a valuable clinical adjunct for even the most expert and experienced surgeons. Although currently hospital-based 3D modeling/printing units are uncommon, they will soon become far more common. For surgeons in developing nations, 3D printing may currently be prohibitively expensive, but 3D modeling is relatively inexpensive and therefore far more accessible. As 3D printer prices continue to fall, the ability to rapidly manufacture prototypes and patient-specific models will inevitably spread through these regions as well. However, the future for 3D-printed medical models, devices, and implants will be limited unless we are able to document their clinical superiority and confirm their value with respect to patient outcomes. Level of Evidence: Level V—expert opinion.

BackgroundOsteoporosis is one of the commonest bone diseases in which bone fragility is increased. Over 300,000 patients present to hospitals in the UK with fragility fractures each year, with medical and social care costs - most of which relate to hip fracture care - at around £2 billion. The number of these fractures rises by 2% a year. The 30 days mortality is 10% and 30% at 1 year. The purpose of this study is to review the current practice according to NICE and BOA guidelines of secondary prevention of osteoporosis and to suggest changes to these guidelines.MethodsPatients over 50 years old admitted as inpatients to our facility with non-neck-of-femur (NOF) fragility fractures in March and September 2008 were studied. Retrospectively (March), looking for risk factors and if treated or not, then prospectively (September), after introducing the new trauma admission sheet. Also cross-sectional study was performed by comparing the services provided for NOF and non-NOF fragility fractures in September. Two-sample t test is used to compare between percentages.ResultsTwenty-nine percent of fragility fractures are non-NOF fractures with a mean age of 70 years, while the remaining 71% are NOF fractures with a mean age of 80 years. There is a great difference in the care provided to these patients: non-NOF fragility fractures got less attention for assessment of osteoporosis (25%) and obtained less interest in investigations by medical staff (11%) and, finally, less intentions to treat osteoporosis (35%), compared to NOF fractures in which 35% of cases were assessed, 47% were investigated and 71% were treated for osteoporosis. Twenty-five percent of NOF fracture patients were found to have previous fragility fractures in the preceding years, while only 6% were on osteoporosis treatment before the fracture.ConclusionOsteoporosis (a new epidemic) is the most common disease of the bone and its incidence is rising rapidly as the population ages. Though treatable, it is often left untreated. We believe that treating patients with non-NOF fragility fractures from osteoporosis before proceeding to NOF fractures would improve their quality of life and reduce the burden on hospital services and funding.

Axons in vitro respond to mechanical stimulus and can be stretched mechanically to increase their rate of growth. This type of accelerated growth under the influence of tensile forces alone appears independent of chemical cues and growth cones. The stretch-growth of axonal tracts ex vivo and their transient lengthening have been discussed in literature extensively; however; evidence of in vivo investigations is scarce. Stretching axons, although practical ex vivo, is more challenging in vivo due to the difficulties of applying in situ axial tensile forces. Here, a technique has been developed to apply axial tensile forces to a peripheral nerve in vivo. A device has been constructed, called a Nerve Stretcher, which makes use of negative gauge pressure to pull sectioned nerve stumps in a confined nerve prosthesis. This article presents the development of this device and a discussion of the methodology used to hold sciatic nerve stumps in a Tshaped nerve prosthesis. The findings of this study will form the basis of future nerve-stretch growth studies.

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Background: Various modalities to facilitate nerve regeneration have been described in the literature with limited success. We hypothesized that negative pressure applied to a sectioned peripheral nerve would enhance nerve regeneration by promoting angiogenesis and axonal lengthening. Methods: Wistar rats’ sciatic nerves were cut (creating ~7 mm nerve gap) and placed into a silicone T-tube, to which negative pressure was applied. The rats were divided into 4 groups: control (no pressure), group A (low pressure: 10 mm Hg), group B (medium pressure: 20/30 mm Hg) and group C (high pressure: 50/70 mm Hg). The nerve segments were retrieved after 7 days for gross and histological analysis. Results: In total, 22 rats completed the study. The control group showed insignificant nerve growth, whereas the 3 negative pressure groups showed nerve growth and nerve gap reduction. The true nerve growth was highest in group A (median: 3.54 mm) compared to group B, C, and control (medians: 1.19 mm, 1.3 mm, and 0.35 mm); however, only group A was found to be significantly different to the control group (** P < 0.01). Similarly, angiogenesis was observed to be significantly greater in group A (** P < 0.01) in comparison to the control. Conclusions: Negative pressure stimulated nerve lengthening and angiogenesis within an in vivo rat model. Low negative pressure (10 mm Hg) provided superior results over the higher negative pressure groups and the control, favoring axonal growth. Further studies are required with greater number of rats and longer recovery time to assess the functional outcome.