The injuries of the acromio-clavicular joint require a differentiated diagnosis and treatment. The classification of the acromio-clavicular dislocations from grade I to grade III according to Tossy is proved. The diagnosis of a complete acromio-clavicular dislocation (Tossy III) is an indication for a surgical repair. Many and different methods are reported in the literature. 178 patients with a fresh acromio-clavicular dislocation (Typ Tossy II and III) were treated at the BG-Unfallklinik Tubingen from 1970 to 1987 by suturing the ligaments, inserting pins across the joint and tension wire bending. In old cases with Tossy III dislocation of the acromio-clavicular joint an oblique osteotomy combined with the reduction of the clavicle is recommended as a method of choice. The results of these procedures and there possible intra- and postoperative complications are reported. The incision along the clavicle quite often gives scar problems. Therefore the advantages of an arched incision across the acromio-clavicular joint is pointed out. Because of there biomechanical relationship fractures in the lateral third of the clavicle are similar to dislocations of the acromio-clavicular joint. The classification of these fractures according to Jager, Buschle and Breitner allows a differentiated management of these lesions.

Injuries of the acromioclavicular joint

The acromioclavicular joint is an important component of the shoulder girdle; it links the axial skeleton with the upper limb. This joint, a planar diarthrodial articulation between the clavicle and the acromion, contains a meniscus-like fibrous disk that is prone to degeneration. The acromioclavicular capsule and ligaments stabilize the joint in the horizontal direction, while the coracoclavicular ligament complex provides vertical stability. Dynamic stability is afforded by the deltoid and trapezius muscles during clavicular and scapular motion. The acromioclavicular joint is susceptible to a broad spectrum of pathologic entities, traumatic and degenerative disorders being the most common. Acromioclavicular joint injury typically affects young adult males and can be categorized by using the Rockwood classification system as one of six types on the basis of the direction and degree of osseous displacement seen on conventional radiographs. MRI enables the radiologist to more accurately assess the regional soft-tissue structures in the setting of high-grade acromioclavicular separation, helping to guide the surgeon's selection of the appropriate management. Involvement of the acromioclavicular joint and its stabilizing ligaments is also important for understanding and classifying distal clavicle fractures. Other pathologic processes encountered at this joint include degenerative disorders; overuse syndromes; and, less commonly, inflammatory arthritides, infection, metabolic disorders, and developmental malformations. Treatment options for acromioclavicular dysfunction include conservative measures, resection arthroplasty for recalcitrant symptoms, and surgical reconstruction techniques for stabilization after major trauma.

Imaging of the Acromioclavicular Joint: Anatomy, Function, Pathologic Features, and Treatment.

A standard handheld cellular telephone for obtaining diagnostic data is described. In at least one aspect, a standard handheld cellular telephone has a processor, a cellular transceiver, a signal transmitter, a signal receiver and memory for storing instructions for execution by the processor. The acoustic, electromagnetic, optical, and positioning functions of a cellular telephone are exploited. The standard handheld cellular telephone is configured to be capable of performing operations including causing the signal transmitter to transmit a signal through a medium when the signal transmitter is placed adjacent to the medium, receiving with the signal receiver one or more propagations of the transmitted signal after the transmitted signal has passed at least in part through the medium, and obtaining diagnostic data from the received one or more signal propagations.

Body measurement and imaging with a mobile device

This paper proposes an innovative technique for monitoring the healing of severe bone fractures using a pair of radio frequency monopoles implanted in the fractured bone. It is envisaged that the screws and external fixation used to stabilise and align the bone will also act as monopole antennas. The proposed antenna configurations were measured inside three novel heterogeneous bone phantoms representing the radius, tibia and phalange bones, and the results were compared to computer simulations with a voxel model of a 26-year-old female from CST Microwave Studio's Virtual Family. The power transmitted from one monopole to the other (S 21) was measured and evaluated as an indicator for fracture healing as blood emulating liquid was injected inside the phantom emulating the conditions of a bone fracture. Finally, for the validation of the phantom measurements, an ex-vivo measurement was conducted using a lamb femur bone. In all cases, the power transmitted from one monopole to the other through the fracture decreased significantly as the volume of the blood representing the fracture increased. The proposed system could provide doctors with a quantitative monitoring tool regarding the healing progress of a fractured bone through the reduction of the wound's hematoma during the first four weeks after the trauma that are critical for bone restoration.

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Bone fracture monitoring using implanted antennas in the radius tibia and phalange heterogeneous bone phantoms

Bone dielectric properties (DP) have been extensively studied. However, little literature has reported DP of bone from identical anatomical site under different status and its correlation with microstructure. Therefore, interrelationship between DP and microstructure of rat femurs with varying bone qualities (normal, osteoporotic and partially osteoporotic) was investigated. Diabetic osteoporosis was induced by streptozotocin (STZ) injection. 8 normal rats as control group together with 16 diabetic rats equally assigned to diabetes mellitus (DM) and DM treated by pulsed electromagnetic fields (PEMF) (DM + PEMF) group were used. DM + PEMF group was daily exposed to PEMF of 15 Hz, 1 mT for 8 weeks. After sacrifice, the femurs were harvested for microCT analysis and dielectric measurements (from 10 Hz to 1 MHz). It was found that DP (conductivity and permittivity) altered after PEMF stimulation improved femoral microstructures (p < 0.01). Significant correlations were found between microstructure indices (MI) and conductivity in the full frequency range (|r| ≥ 0.64, n = 24) as well as permittivity in middle and low frequencies (|r| ≥ 0.52, n = 24, from 1 Hz to 1 kHz). The findings demonstrated the good correlation between DP and MI of femoral bone in rats, which makes it possible to distinguish bone under different status and predict MI variation through dielectric measurements.

The Correlation Between Dielectric Properties and Microstructure of Femoral Bone in Rats with Different Bone Qualities

The medial coracoclavicular ligament: anatomy, biomechanics,and clinical relevance-a research study.

The increasing research on development of novel bio-materials has resulted in several studies on non-destructive evaluation methods for characterizing these materials and the biological materials receiving them. A broad range of techniques are available. As an alternative tool, electrical impedance spectroscopy, has become a widely used, non destructive and low cost technique in material quality evaluation. Particularly in bones, it has also been demonstrated that mechanical characteristics are strongly correlated to dielectric properties. In this work, non destructive estimation (the same samples can be tested using other techniques) of the dielectric properties of fresh trabecular bones (layered lossy structure) using coaxial probes is analyzed from 1MHz to 10MHz (in frequency domain) and from 80MHz to 1GHz (in both, frequency and time domain). Frequency domain system identification is used to build the estimation in the low frequency range and an orthonormal based identification approach, for the high frequency data. Comments on conductive samples, non Debye dielectrics and polarization effects are added. The methodology was applied to a particular human sample population of aged adult femur heads and results are presented here. A comparison with destructive test, in which the samples were machined into cylinders of 7mm diameter, is also performed.

Dielectric Properties in Fresh Trabecular Bone Tissue from 1MHz to 1000MHz: A Fast and Non Destructive Quality Evaluation Technique

Economical reasons to research and develop new materials are very strong and the main market for biotechnology is human health. Bone is one of the most studied biological material; data and models at different organization levels describe relevant features needed in different applications. Depending on the type of bone, the anatomical location, the human population considered and the level taken into account, the descriptions can differ substantially. In this work, we present a set of properties (mechanical and architectural ones) measured on fresh trabecular bones samples that were extracted from femur heads of live donors with hip total replacement. Standard procedures to preserve the samples were followed. Engineering and clinical tests were performed and custom-built tools were made to adapt the available equipment.

Experimental Techniques to Evaluate In Vitro Trabecular Bone Properties and Emerging Numerical Model

BackgroundDistal-ulna stump (DUS) instability often occurs when performing a distal radioulnar joint (DRUJ) arthroplasty. Recent studies suggest that the distal interosseous membrane (DIOM) reinfor...

Distal-Ulna Stump Stability: The Role of Distal Interosseous Membrane: Myth or Reality? Anatomical Research.

Three-dimensional (3D) printing includes a group of technologies by means of which it is possible to generate three-dimensional objects from binary information. Orthopedics and traumatology are fields of medicine in which 3D planning has had the greatest impact, especially in trauma and oncological orthopedics. Applications of this technique include diagnosis, surgical planning, intraoperative guide creation, custom implants, surgical training, orthotic and prosthetic impression, and bioprinting. Advantages have been demonstrated in its use, such as greater technical precision, shorter surgical times, decreased blood loss and less exposure to X-rays. Although the process is increasingly optimized and accessible due to advances in software and automation, it is a technique that requires adequate training. The objective of this review is to offer an approach to this technology and its basic principles.

Sergio Valente

Papers

The medial coracoclavicular ligament: anatomy, biomechanics,and clinical relevance-a research study.

Dielectric Properties in Fresh Trabecular Bone Tissue from 1MHz to 1000MHz: A Fast and Non Destructive Quality Evaluation Technique

Experimental Techniques to Evaluate In Vitro Trabecular Bone Properties and Emerging Numerical Model

Distal-Ulna Stump Stability: The Role of Distal Interosseous Membrane: Myth or Reality? Anatomical Research.

[Use of preoperative planning and 3D printing in orthopedics and traumatology: entering a new era].