Explore the vast range of titles available.

In this original and controversial book, historian and philosopher Reviel Netz explores the development of a controlling and pain-inducing technology—barbed wire. Surveying its development from 1874 to 1954, Netz describes its use to control cattle during the colonization of the American West and to control people in Nazi concentration camps and the Russian Gulag. Physical control over space was no longer symbolic after 1874. This is a history told from the perspective of its victims. With vivid examples of the interconnectedness of humans, animals, and the environment, this dramatic account of barbed wire presents modern history through the lens of motion being prevented. Drawing together the history of humans and animals, Netz delivers a compelling new perspective on the issues of colonialism, capitalism, warfare, globalization, violence, and suffering. Theoretically sophisticated but written with a broad readership in mind, Barbed Wire calls for nothing less than a reconsideration of modernity.

Category: Midfoot/Forefoot; Trauma Introduction/Purpose: The great toe plays a large role in activity, including maintenance of balance and substantial weight bearing capabilities. Fractures of the hallux distal phalanx, especially when displaced or unstable, can lead to significant dysfunction of the interphalangeal joint (IP) and pain and may need operative intervention. Surgical options include wire pinning, screw fixation, external fixation, arthrodesis, or amputation. For patients with significant comminution and shortening who would like to attempt toe salvage without fusion, external fixation can lead to great outcomes. Unfortunately, the use of these devices is hindered by cost, size, and availability. We recommend the use of a novel low cost external fixation device that can be made intraoperatively using common materials found in the operative room. Methods: A 27-year-old female, with a severely comminuted right distal phalanx fracture with interphalangeal (IP) joint dislocation, presented 4 days after a skiing accident. We discussed treatment may require IP joint arthrodesis or partial amputation, however, salvage fixation could be attempted initially. First, a transverse percutaneous wire was placed through the distal phalanx tip since the fragment was still mostly intact. The wire exited the skin medially. Two Kocher clamps to each side of the wire were applied for distraction of the fracture site while simultaneous manual manipulation of the more proximal fragments was performed. Once reduced, three more proximal transverse wires were placed through a 3cc syringe, which acted as a rail to hold the fracture length stable. The distal transverse wire was then impaled through the rail so that all four wires were within the rail providing two points of fixation in the distal phalanx and proximal phalanx. Results: The patient's weight-bearing status was non-weight bearing to the right lower extremity for 6 weeks. This was actually being dictated by the more proximal tibial plateau fracture for which she was non-weight bearing. With regard specifically to the hallux fracture, she could have been heel weight beared immediately. At her most recent post-operative visit at 6 weeks, she was doing well with minimal pain. The external fixation device was removed in clinic and she was transitioned to a post-op shoe and allowed to weight bear as tolerated. She was motor and sensate intact with the ability to actively range her IP joint. Radiographs at the most recent visit revealed excellent alignment of the toe with minimal articular step off. Conclusion: With severely unstable hallux distal phalanx fractures, operative intervention should be considered. For those with a significant degree of comminution who still would like to undergo salvage fixation, external fixation is an excellent option. Unfortunately, the use of these devices is hindered by cost, size, and availability. Hand surgeons solved this problem by introducing small, low cost external fixators composed of common materials such as needle sheaths, IV cannulas, and syringes. We adapted their model to the toes and were able to obtain great clinical outcomes with low cost, all the while maintaining the patient's expectations for cosmesis.

Category: Bunion; Midfoot/Forefoot Introduction/Purpose: Distal 1st metatarsal chevron osteotomy is one of the most frequently performed procedures for treatment of mild to moderate hallux valgus, though the optimal method of fixation remains in question. The use of Kirschner wires (K-wires) is an established technique of temporary internal fixation that offers a simple and cost-effective strategy. Previous studies have reported removal of K-wires ranging from 4-8 weeks following a chevron osteotomy, though even earlier removal may be acceptable and serve to decrease the risk of complications. The purpose of this study was to determine if early removal of K-wires is adequate to maintain correction of a hallux valgus deformity following distal 1st metatarsal chevron osteotomy. Methods: We conducted a retrospective review of patients who had their 1st metatarsal K-wire removed at their first (2week) postoperative visit after undergoing primary chevron osteotomy for treatment of a hallux valgus deformity with a single foot and ankle fellowship-trained orthopaedic surgeon from 2010-2018. Exclusion criteria consisted of revision osteotomies, K-wire removal >=21 days postoperatively, concomitant midfoot or hindfoot procedures, and lack of preoperative or at least 3-month postoperative radiographs. Preoperative, 6-week, 3-month, and longer-term intermetatarsal angles (IMA) were measured on weightbearing anteroposterior (AP) radiographs by an individual blinded to and not involved in the care of the patients. The pre- and postoperative tibial sesamoid position according to the Hardy and Clapham classification (grades 1-7) was also recorded on those with longer-term AP radiographs on file. From 2010-2018, 275 patients underwent 295 primary chevron osteotomies by the senior author, with 72 osteotomies (24.4%) excluded, leaving 223 (75.6%) available for analysis. Results: Patients had a mean preoperative IMA of 11.4 +- 2.0 degrees. At 6 weeks, 3 months, and longer-term follow-up averaging 24.6 months, patients had mean IMA of 3.8 +- 1.7, 4.6 +- 1.7, and 4.6 +- 2.2 degrees, respectively, all of which were significantly less (P<0.0001) than the mean preoperative IMA. Of those with longer-term follow-up (n=56, 25.1%), the tibial sesamoid position decreased from 4.6 +- 0.8 preoperatively to 2.3 +- 0.7 at 6 weeks, 2.4 +- 0.8 at 3 months, and 2.6 +- 0.9 at final follow-up. All 3 postoperative time points of tibial sesamoid positions were significantly less (P<0.0001) than the mean preoperative position. Conclusion: Our findings demonstrate that removal of K-wires less than 3 weeks following a distal 1st metatarsal chevron osteotomy is sufficient to maintain correction of hallux valgus deformity. The loss of correction in this study is in line with previous studies, where K-wires were removed at later postoperative time points. Delayed wire removal has been shown to lead to increased complications, such as pin tract infection and bending or breakage of the K-wire, which can require not only additional office visits but also potential revision procedures. Removing the K-wire in the early postoperative period should be considered effective and safe.

Wire electrical discharge machining (WEDM) is an important technology, which demands high-speed cutting and high-precision machining to realize productivity and improved accuracy for manufacturing hard materials. WEDM has experienced explosive growth and complexity of equipment as well as rising demand for the basic process tool (the wire electrode). Greater taper angles, thicker workpieces, automatic wire threading, and long periods of unattended operation make the selection of the ideal wire a much more critical basis for achieving successful operation. This paper focuses on the evolution of EDM wire electrode technologies from using copper to the widely employed brass wire electrodes and from brass wire electrodes to the latest coated wire electrodes. Wire electrodes have been developed to help user demand and needs through maximum productivity and quantity by choosing the best wire. In the final part of the paper, the possible trends for future WEDM electrode research are discussed.

Category: Bunion, Midfoot/Forefoot Introduction/Purpose: The lapidus procedure is a longstanding operation performed for the treatment of hallux valgus deformity with a concomitant hypermobile first ray. Orthopaedic surgeons have a myriad of options to choose from in performing the lapidus procedure. The implantation of orthopaedic implants comes with the risk of iatrogenic injury to surrounding anatomy. Several cadaveric studies in the humerus and femur have described potential neurovascular structures at risk during placement of intramedullary nail systems. The purpose of this study was to determine the proximity of nail insertion and interlocking mechanisms in the Lapidus Phantom Intramedullary Nail System (Paragon 28, Inc.) to neurologic and tendinous structures in the foot. Methods: A titanium intramedullary nail was inserted from the first metatarsal to the medial cuneiform spanning the first tarsometatarsal joint in 10 fresh-frozen cadaver feet. K-wires were inserted in the proximal lateral, proximal medial, and distal medial-to-lateral interlock screw paths. The tibialis anterior tendon, extensor hallucis longus tendon, and superficial peroneal nerve were carefully dissected and exposed, and the distance from each of these anatomic landmarks were then measured and recorded from four different aspects of the nail: Proximal lateral interlocking screw path, proximal medial interlocking screw path, nail insertion, distal interlocking screw path. Distances were averaged, ranges were determined. Results: The tibialis anterior tendon was in closest proximity to the proximal medial interlock K-wire with an average distance of 0.4 mm. The proximal medial interlock bisected the tibialis anterior tendon in three of the specimens. The extensor hallucis longus tendon was in closest proximity to the nail insertion with an average distance of 1.2 mm. A branch of the superficial peroneal nerve was in closest proximity to the distal interlock K-wire with an average distance of 7.5 mm, however, the nerve came in direct contact with the proximal medial interlock K-wire in two of the specimens. Conclusion: The Lapidus intramedullary nail’s proximal medial interlock screw poses the greatest threat to the tibialis anterior tendon, with the distance from the tendon to the interlock K-wire being 3 mm or less in all specimens tested. The extensor hallucis longus tendon is at risk of injury with insertion of the nail. Medial to lateral interlocking poses the greatest danger to a branch of the superficial peroneal nerve. Blunt dissection should be performed using this system with a path to bone before instrumentation to reduce the risk of nerve and tendon injury in the foot.

Aiming at enhancing the forward and inversion efficiency of grounded long wire source TEM (Transient ElectroMagnetic method), a new rapid layered medium forward method is proposed in the paper. This forward method is based on two points, one is to approximate the vertical magnetic component in frequency domain of a grounded long wire source by the response of several circular loops, and the other is to introduce the technique of \"flow through\" into the digital filtering calculation of sinusoidal transformation. The result of model tests shows that the calculation efficiency of proposed method is improved greatly (dozens of times) compared with that of the conventional method.

In the present study, our emphasis was directed towards the fabrication process of long multi-core superconducting wires, each spanning several hundred meters. These wires feature an in situ MgB2 core, an ex situ MgB2 barrier, and a copper shield. The cost-effectiveness of these constituent materials, coupled with a judicious arrangement of internal components, facilitates the utilization of an economical shielding material for the resulting wire. Our ongoing efforts have successfully yielded several hundred-meter-long wire sections possessing favorable superconducting characteristics, making them suitable for self-field applications, such as direct current (DC) power lines.

Helical steel wire ropes generate deterministic topology induced structural magnetic fields in the surrounding air under permanent magnet excitation, which superpose with defect induced incremental fields and complicate magnetic flux leakage interpretation. This work formulates the exterior magnetostatic problem in a homogeneous non magnetic air domain and derives an explicit kernel integral representation in which the free space kernel is invariant and the geometry enters only through helical parameterization and phase shift superposition. The analysis explains coupled circumferential and axial periodicities of intact responses, predicts lift off induced attenuation and smoothing of structural fluctuations, and accounts for the oblique spatial bias of single wire break responses as a topology driven shift along the local lay direction. Three dimensional finite element simulations for rod 1S19W and 7S133W configurations corroborate these trends.