Illinois Prosthetics Technology
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Types of Joint Prosthetics January 16, 2015

The cartilage pads the in-between of the bones in a joint. It can wear down over time which will lead the bones to be rubbing against each other and this will be causing severe pain as well as decreased movement. The prosthetics are the ones commonly used in replacing the joints which have already been damaged. Prosthesis is the replacement of a missing part by making use of an artificial substitute. The replacement or the addition of structural elements which are within a joint for the enhancement and improvement of the function of the joint is referred to as joint prosthesis.

Joint arthroplasty is the most common orthopedic procedure that is performed following a fracture fixation. The major indications for the joint replacement include the inflammatory arthropathy, complicated fractures, degenerative joint disease, and avascular necrosis. Joint arthroplasty is contraindicated for systemic and joint infection as well as for neuropathic joint.

hip-joint-prostheticsBelow are the various types of joint prosthetics:

• Hip Replacement – It is a surgical procedure wherein the joint in the hip is being replaced with a prosthetic implant. It may be performed as a half replacement which replaces only the femoral head. It can also be performed as a total replacement wherein it replaces both of the femoral head and the acetabulum.

• Knee Replacement – It is otherwise known as the knee arthroplasty. It is a surgical procedure for the replacement of the weight-bearing surfaces of the knee joint for the purpose of relieving both pain and disability. The performance of the knee replacement surgery can be as a total or partial knee replacement. Generally, the surgery consists of the replacement of the damaged or diseased joint surfaces of the knee using metal and plastic components which are shaped to let the knee have the continued motion.

• Shoulder Replacement – It is a surgical procedure wherein a part of all of the glenohumeral joint is being replaced with a prosthetic implant. The general purpose of the joint replacement surgery is for the relief of arthritis pain or to fix severe physical damage of the joint.

• Ankle Replacement – It is otherwise known as the ankle arthroplasty. It is a surgical procedure performed for the replacement of the damaged articular surfaces of the ankle joint in humans using the prosthetic components. The key feature of the ankle replacement is to restore the range of motion. Its prosthesis replicates the original joint function as it restores the appropriate kinematics at the joint that is being replaced. It permits a good fixation of the components where there is involvement of an appropriate load transfer to the bone and will have minimal risk of loosening. It provides a guaranteed longevity of the implant that is particularly related to wear resistance.

Like any other surgical procedure, joint replacement may pose some risks. It is essential to consult with the doctors to know the potential risks and complications especially those that are related to the surgery itself or those which may happen over time following the surgery.

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Types of Arm Prosthesis October 29, 2014

Prosthesis refers to the artificial device used for the replacement of a missing body part which may be lost due to a disease, trauma, or congenital conditions. The rehabilitation of the prosthetic amputee is primarily being coordinated by the prosthetist as well as the inter-disciplinary team of health care professionals like the physiotherapists. The prostheses these days are durable, light-weight, and most essentially fully functional. They have been made of materials including silicone, aluminum, carbon fiber, titanium, and plastics. The components include the socket, the pylon or frame, or the suspension system. There are some prosthetics which are being attached to the body with the use of a strap and a harness system. Other prosthetics are making use of suction.

arm-prosthesisThere are various types of prosthetic arm devices and each of which has been designed for the satisfaction of the specific needs of the amputee. Below are the different types of arm prosthesis:

Body-Powered – it is a kind of prosthesis that utilizes a cable harness system that is being attached to the residual limb and it relies according to the movement of the limbs in controlling the prosthesis. The three cable system will let the person have the control to grasp, flex the elbow, and lock the elbow. It has two main types including the Voluntary Open, wherein the hand is being opened with the cable and then automatically closes, and the Voluntary Close, wherein the hand will close upon the application of tension to the cable. This kind of prosthesis is inexpensive with high reliability making it dependable as well as accessible. There are some levels of amputation or deficiency which may let an elbow system to be added for functional improvement.

Electrically Powered – it makes use of electrical impulses coming from the residual limb muscles. It requires no usage of a harness or cable which is the reason why it can be built to look like similar to the real arm. It is operated with the use of rechargeable batteries making both the body movement as well as the body strength to be not as vital for their operation. This device is able to provide a strong grip force which is usually exceeding to 20 to 30 pounds.

Hybrid – it utilizes the sensors as well as the microprocessors in interpreting the electric impulses and then controlling the function of the artificial arm. It is a combination of the electrical power and the body power. Majority of the hybrid prostheses are being used for people having trans-humeral amputations or deficiencies located above the elbow.

Activity-specific – it is the prosthesis that is designed to be used in sports, specific occupations, or other daily activities. Its design is for activities requiring some function as well as durability that other prostheses may not be able to provide. These kinds of prostheses will allow the person to get out and become active. Its innovative creation will let the individuals get into various kinds of hobbies, sports, and recreation including swimming, hunting, weight-lifting, fishing, golfing, riding bicycle, and other music or work-related activities.

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Video Lecture of Advances in Prosthesis Design September 27, 2014

In this video David Chandonnet the Chief of Prosthetics at the VA Health Care System in Providence, RI and Dan LeBlanc, the retired Director of Veterans Services, in New Bedford, MA talk about questions, issues and concerns regarding amputation and advances in prosthesis.

There are many different types of prosthesis and their components. The prescription of these devices can be quite varied depending on the individual and their age and lifestyle. In the lecture you can hear first hand experience from an amputee and how they coped with the grief process and adjusting to the changes associated with the loss.

This video is brought to you by Bridgewater State Universities, Children’s Physical Developmental Clinic Guest Lecturer Series. You can learn more about the series by visiting – www.bridgew.edu/cpdc

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Categories: Prosthetic Devices

Types of Prosthetic Hands August 27, 2014

About 10,000 new cases of upper extremity amputations are recorded annually with trauma and surgery as the top two most typical reasons for undergoing the procedure. Although there are many individuals who have upper extremity amputation, only half of the amputee population uses some kind of prosthesis.

The importance of wearing hand prosthetics is reflected through its various purposes in everyday living. Aside from providing favorable aesthetic results, this procedure can also help in accomplishing the daily, recreational and vocational tasks of the person. Every individual has a unique and special need in completing activities of daily living so the management of hand prosthesis is done in a personalized approach.

Similar to the technological innovations applied to the lower extremity prosthetics, the field of medicine has also witnessed some important developments in the utilization of upper extremity prosthetics. With the advent of computer technology, the use of hand prosthetics has immensely advanced in terms of its aesthetic and functional features.

prosthetic-handsHand prosthetics can be classified into three main types:

1. Conventional or Body Powered Hand Prosthetics

This type of upper extremity prosthetic device works with the use of a harness system. Performing a specific movement of the body will control the harness system. The heavy duty structure of the body powered prosthetics makes it more durable. Because of its construction, it is also good at proprioception and is less heavy as compared to the myoelectric ones. Conventional types are cheaper than the other forms and will not require as much maintenance to the user.

2. External Power or Myoelectric Hand Prosthetics

External hand prosthetics does not need the use of a harness system. Instead, the device is controlled by utilizing an electric motor that is powered by batteries. EMG signals coming from the skin are perceived by the sensors implanted in the socket. The EMG signals are then transmitted to a processor which takes charge of how the motor should function. For more positive results of this prosthetic usage, intensive training is required.

3. Cosmetic or Passive Functional Hand Prosthetics

Cosmetic hand prosthetics is considered as an aesthetic device because it copies the appearance of the amputated hand and serves as a replacement. However, it can also function by assisting in simple carrying and balancing of things. This type of prosthetic device is aesthetically helpful, requires minimum maintenance and is not heavy to use.

4. Hybrid Prosthetics

Combing the functions of a conventional and myoelectric hand prosthetics will result in a hybrid type of prosthetic device. Hybrid hand prosthetics is best applied to individuals with above-the-elbow (transhumeral) amputations which can bring back the function of the hand and elbow. Both the harness system and external power source control the elbow joint device.

5. Recreational or Adaptive Hand Prosthetics

An adaptive or recreational hand prosthetics is custom-made according to a specific activity or function needed. Recreational activities like playing instruments, sports (fishing, golfing and skiing), shooting pool and construction work may require some specific kind of upper extremity prosthetic that suits how the person might want to use it.

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Prosthetic Knees July 21, 2014

Knee replacement or knee arthroplasty is the reconstruction of the knee joint which is damaged by means of a surgical procedure. It aims in relieving pain as well as restoring joint motion and stability. Early attempts in treating severe joint destruction have made used of soft interpositional materials like human, animal, and synthetic membranes but none succeeded due to the materials which are not able to withstand the wear or even maintain the stability of the joint. Metallic implant materials have been developed beginning 1940 and the ceramic or metal prostheses since then became part of the knee reconstruction. The knee replacement refers to the usage of hinge-type prostheses. These days, all of the contemporary prostheses will be resurfacing the degraded joint surfaces and still the procedure is considered as replacement for the knee joint.

prosthetic-kneeNowadays, all of the prostheses make use of polyethylene intended for the tibial and frequently the patellar articulating surfaces. The metal-on-metal implants have been originally used however the corrosion occurred which led to the limitation of their success. Polyethylene has been constantly used for over forty years for the surgical procedure of knee replacement. Knee prostheses are being secured to the underlying bone with the utilization of acrylic resins or porous metal surface for anchoring cement.

The kind of knee being used for the above knee prosthesis depends on the client’s level of activity, strength as well as ability of knee control, weight of the client, length of the residual limb, preference of the patient, and funding. Friction is utilized in the knees for controlling the knee joint when walking. The friction is responsible to control the distance and speed of the knee bending and straightening during gait. There are knees that have mechanical friction and others have the hydraulic resistance. The computerized knees control the knee speed depending on the gait of the client. The mechanical knees are responsible for the provision of constant friction. The computerized knees and hydraulic knees are responsible for the knee speed change based on the speed of the walking client.

Manual Locking Knee – It is the most stable knee utilized in prosthetics wherein the knee is locked at the time of gait and the client releases the lock mechanism so that he or she can sit down. These knees are intended for clients having very short residual limbs or poor hip strength as well as for those losing abilities in controlling the knee.

Single Axis Constant Friction Knees – These are basic knees that can bend freely and are utilized by kids having a lower center of gravity or for clients having excellent musculature control that walks at only one speed.
Weight Activated Stance Control Knee – It is widely used and is a single axis constant friction having a braking mechanism.

Polycentric Knees – It has variable center of rotation that allows having stable gait phases. It lets the knee to have easy bending for sitting.

Hydraulic Knees – These allow adjustments for the speed of walking using hydraulics, which include either air or liquid, within the knee.

Programmable or Computerized Knees – These make use of remote handheld, programs, or software for the adjustment of one’s gait and speed in walking.

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Categories: Prosthetic Devices