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Fuller: Chapter 31: Orthopedic Surgery

Terms in this set (73)

1. •Synarthrosis (suture joint): A joint with limited movement or fixed articular surfaces, such as between the skull bones.

2. •Amphiarthrosis (cartilaginous joint): A joint in which the bones are connected by cartilage and only slightly moveable. The symphysis joints are included in this category (e.g., symphysis pubis).

3. •Diarthrosis (synovial joint): A joint that is freely moveable, such as the hip or the shoulder. Most joints of the body are diarthroses. They are also called synovial joints because the joint capsule contains a fluid called synovial fluid.

a. •Hinge joint: A joint that has rocker and cradle components, which allow extension and flexion only (e.g., the elbow).

b. •Saddle joint: A joint in which the two components have a complementary convex-concave shape, and the bones slide over each other. The body has only one saddle joint, which is in the thumb. This joint allows flexion, extension, abduction, and adduction.

c. •Gliding joint: A joint in which relatively flat surfaces of bone slide over each other (e.g., the vertebrae, movement of which allows the spine to flex).

d. •Ball-and-socket joint: A joint with a spherical component and a concave component. Movement occurs in several planes, making this joint the most freely moveable type (e.g., the hip and the humerus). Ball-andsocket joints allow flexion, extension, abduction, adduction, rotation, and circumduction.

e. •Pivot joint: A joint composed of a bony protuberance and an open collar component (e.g., the first and second vertebrae of the neck). This type of joint allows rotation.

f. •Condyloid joint: A joint in which a small protrusion (condyle) slides within a slightly elliptical component (e.g., the carpal bones of the wrist). Condyloid joints allow flexion, extension, abduction, and adduction.
static, or neutralization, plate spans a two-fragment fracture and is fixed in place with lag screws. This is a simple means of stabilizing (i.e., neutralizing) force acting on the bone fragments with no mechanical action on the fracture line. This type of plate is used when the fragments can be compressed manually and the fracture is stable (Figure 31-26). The plate also is used to reduce a fracture

reconstruction plate may be bent to fit the contours of the bone surface. First, an aluminum template is fitted over the bone to duplicate its contour. The template then is taken to the back table and the implant plate is shaped with pliers, a plate press, and other instruments. More delicate reconstruction plates may be shaped and cut to size by hand. This type of plate is used commonly in facial and cranial fractures

locking plate has threaded screw holes that lock the screws into the plate. This prevents rocking of the screws, which tends to loosen them or cause them to back out.

dynamic compression plate has screw holes that are inclined (sloped) and offset. This design feature provides reduction and compression of the fragments. Anchor screws are inserted into one fragment. As the screws are tightened, the plate slides along the bone, drawing the two bone fragments together (Figure 31-29). The term dynamic refers to the compression of bone fragments produced by the natural load exerted on the bones by the body itself. A low-contact dynamic compression plate is designed to reduce contact between the plate and the bone.

The tension band plate is placed on the convex or gap side of the fracture to counteract the load and prevent the gap from widening.

buttress is a supporting structure that prevents an adjoining object or structure from collapsing. a buttress plate is used to give added strength or to "prop" one structure against another.

condylar plate often is used in conjunction with a compression screw for fixation of fractures of the condyle (the rounded

During healing, the plate-nail combination shifts the load from the trochanter (normal loading) to the long axis of the femur, removing excess pressure from the trochanter
Many implants, including joint components, are supplied by the manufacturer individually in sterile packages. Plates, screws, pins, and rods are not wrapped individually but supplied in sterile sets, from which the appropriate size is selected during surgery. Joint and other specialty implants that are sterilized and packaged by the manufacturer are opened onto the sterile field only after the exact size and type have been determined. This reduces environmental exposure during surgery, as well as the need for an excessive implant inventory. Implants must not be flash-sterilized except in extreme emergency. The Association for the Advancement of Medical Instrumentation (AAMI), which institutes international protocols for patient safety, states that "careful planning, appropriate packaging, and inventory management in cooperation with suppliers can minimize the need to flash-sterilize implants." 1 The Association of periOperative Registered Nurses (AORN) recommends that if an emergency situation makes flash sterilization unavoidable, a biological monitoring device must be used, along with a chemical indicator. The implant must not be used until the biological indicator provides a negative result. 2 The patient's permanent operative record must reflect the details of the sterilization process and the outcome of the biological and chemical indicators. The sterilizer log (computer printout), which includes all sterilization parameters achieved when the implant was flashed, must be included in the patient's chart. The AAMI provides yearly updates of accepted sterilization practices through its Standards Registry. Standard ST79 provides current practices regarding steam sterilization for implants and should be consulted yearly for updated information.