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dard arthroscope. Special cannulated obturators also allow passage of the cannula/obturator assembly over a Nitanol guidewire prepositioned in the joint through 6-inch, 17-gauge spinal needles (Figure 10.7). The

FIGURE 10.6. A standard arthroscopic cannula (a) is compared with the extra-length cannula (b). A modified bridge (c) has been shortened to accommodate the extra-length cannula with a standard length arthroscope. Extra-length blades (d) are also available compared with the standard length blades (e).

FIGURE 10.6. A standard arthroscopic cannula (a) is compared with the extra-length cannula (b). A modified bridge (c) has been shortened to accommodate the extra-length cannula with a standard length arthroscope. Extra-length blades (d) are also available compared with the standard length blades (e).

scrub nurse's Mayo stand contains the instruments routinely needed for each case (Figure 10.8). The 5.0mm cannula is used for initial introduction of the arthroscope while the inflow is attached. The diameter allows adequate flow for the fluid management system attached through the bridge. Once all three portals have been established, the inflow can be switched to one of the other cannulas and the 5.0-mm cannula replaced with a 4.5-mm cannula. The use of three 4.5mm cannulas allows complete interchangeability of the arthroscope, instruments, and inflow. The 5.5-mm cannula is available for larger shaver blades.

Extra-length blades are available. Curved designs are especially helpful for maneuvering within the spherical geometry of the joint. These can be passed through specially designed slotted cannulas (Figure 10.9) that accommodate the curved shaver blades as well as other hand instruments. Specially designed hand instruments must be longer, but also of sturdy construction to minimize the risk of instrument breakage.

Thermal ablation devices demonstrate specific advantages in the hip. The small diameter allows access

FIGURE 10.7. The cannulated obturator system allows for greater ease and reliably establishing the portals once proper positioning has been achieved with the spinal needle. The 6-inch, 17-gauge spinal needle (a, b) accommodates passage of a Nitanol wire (b, c). Specially treated, the wire is resistant to kinking. The cannulated obturator allows for passage of the obturator/cannula assembly over the guidewire (c).

FIGURE 10.7. The cannulated obturator system allows for greater ease and reliably establishing the portals once proper positioning has been achieved with the spinal needle. The 6-inch, 17-gauge spinal needle (a, b) accommodates passage of a Nitanol wire (b, c). Specially treated, the wire is resistant to kinking. The cannulated obturator allows for passage of the obturator/cannula assembly over the guidewire (c).

to recesses within the joint difficult to access with mechanical blades. Also, because of the limits on maneuverability, it can be difficult for the shaver to excise damaged articular cartilage or labrum and create a stable edge. Thermal devices are often much more effective at creating a smooth transition zone, preserving more healthy tissue.

FIGURE 10.9. A slotted cannula with its accompanying cannulated obturator accommodates passage of curved shaver blades and larger hand instruments into the joint.
Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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