Size of the devices:
The role of the large-diameter ASR devices in males are linked with considerably lower metal ion levels in contrast to the BHR devices, proposing that under perfect in vivo conditions the ASR has a less wear rate than the BHR device (Underwood et al. 2011). Although, problems also occurred with the smaller hip resurfacing implants among women and small men. It was discovered that these implants did not lubricate as well, unlike the bigger implants and therefore they produced a large amount of metal debris and produced a very concentration of metal ions in the blood. (Cohen 2012).
Acetabular component:
The BHR hip device is more innovative than the ASR device as it has a hole used for wires to fix the introducer. The ASR device does not have this. (Underwood et al. 2011).
Positioning of the components:
The difference can be seen in the sub optimally positioned components within 10° of Lewinnek’s safe zone in the occurrence of edge loading and rate of wear in both the ASR and the BHR devices (Underwood et al. 2011).
Wear and inclination of the acetabular component:
A major positive correlation was seen between the wear and inclination of the acetabular component with the BHR device (p = 0.01) which was not seen with the ASR device (p = 0.6). This suggests either that the ASR devices have a higher wear rate at all inclinations or that the ‘safe zone’ that escapes edge loading is a lot thinner than that of the BHR device (Underwood et al. 2011).
The magnetic field generated by the MRI is so strong that metal-containing items are strongly attracted to the magnet. Because the hip joint is made of metal, a lead shield must be used during the procedure.
Considering some of the negative experiences surgeons discussed in relation to the second generation polymers, Synthes could potentially damage its reputation as a provider of the highest quality and most secure products in the market. Synthes’ relationship with AO is a tremendous asset that creates a brand image that is difficult for competitors to replicate. Thus Synthes could be risking arguably its most vital success factor by launching products that have not been entirely clinically proven. Another major problem is the fact that the second generation polymers would be mainly applicable to injuries to short bones such as hands, wrists, feet, and ankles. According to Table A, fractures to long bones are a significantly larger portion of the market, which is a segment Synthes would forgo should it launch products using the second generation
Synthes has several threats to consider in the near and upcoming future. The first threat we can talk about is with regards to imitation. Imitation is a big deal in the internal fixation device industry. Synthes has become the leader in this market due to several competitive advantages, for example the affiliation with AO, which surgeons take as a sign of confidence. These advantages have been able to sustain them with huge market share and very high sales during the last 20 years. They have also created other competitive advantages within
The acetabular components have a "spherical outer surface with at least one hole to permit the surgeon to determine if the prosthesis is fully impacted into place" (Skinner 399). The inner surface of the acetabular component then locks the UHMWPE to limit rotation and dissociation (Skinner 399). There are two crucial factors when choosing the implants. First, if the prosthesis is too stiff then the patient may suffer from proximal osteopenia. Second, the stiffer the prosthesis is the more likely the patient will experience pain in the thigh. To avoid these two factors the surgeon should elect to use titanium ally instead of the cobalt chromium alloy.
Total joint replacements are very common in the United States, and are becoming even more common with increasing obesity rates and an increase in life expectancy. Long-lasting and high-performance implants are needed for the younger, active population that receives them. The Agency for Healthcare Research and Quality states more than 285,000 total hip arthroplasties (THA) and 600,000 total knee arthroplasties (TKA) are performed in the United States alone each year (2). Longevity of these joint replacements is dependent on several factors: the durability of the fixation of the implant surface to the bone, the bearing surface’s wear rate, and the accuracy of the surgeon in implantation of the total joint (2). Of these total joint replacements, periprosthetic osteolysis and aseptic loosening occurs in about twenty percent of cases, and aseptic loosening is responsible for about seventy-five percent of total joint replacement failures (2). This is
Long-leg. X-ray evaluations were also performed to assess final MA alignment. Values of MA larger than 3° were considered as outlier.
Total hip arthroplasty (THA), commonly known as hip replacement, is a reconstructive orthopedic procedure that involves the surgical excision of the head and proximal neck of the femur and removal of the acetabular cartilage and subchondral bone(A). The damaged joint is replaced with an implant that mimics the motion of the natural joint and is made from combinations of metal, plastic and/or ceramic components(D).
The bone structure of a normal hip consists of an acetabular and a femoral head, which is covered with articular cartilage, a smooth and strong cover. There is then a ring of cartilage which is called the acetabular labrum. This provides stability, maintains joint fluid pressure and distributes weight to the femoral head. With poor coverage of the femoral
From peg legs and hooks to robotic arms and legs, prosthetics have made an outstanding leap. Prosthetics have enabled amputees to regain mobility and their lives. The advancements in prosthetics have also led to a better understanding in surgical amputation and the construction of prosthetics. The question is what influenced the advancements of prosthetics and how it affected prosthetics. The answer lies within the history and the physiological components of prosthetics. Mobility and function, physiological components, and war all played an important role in the advancements of prosthetics.
The Association for the Study of Internal Fixation (AO) formed in 1958 to improve and standardize the state of internal
Joint replacements are among the most common and successful orthopedic surgeries, giving more people the opportunity to remain active well into their golden years. (American) The American Academy of Orthopaedic Surgeons estimates there are more than 300,000 total hip replacements (THRs) and 600,000 total knee replacements (TKRs) performed every year—numbers that will only increase in the future. Most patients who undergo total joint replacement, or arthroplasty, experience a dramatic reduction in pain and a significant improvement in their ability to function in daily life. (American Hip)
The continuous aging of the human body combined with the stress of physical activities create a repeated stress on the joints of our bodies that carry the potential risk of developing osteoarthritis. Osteoarthritis is one of the most common forms of arthritis that is the worsening of the joints occurring particularly in the hands, knees, and hip. Osteoarthritis occurs primarily with elderly individuals who have severely worsened their joints leading to disability. When studying joint deterioration “radiographic signs of OA include joint space narrowing, subchondral bone sclerosis, and osteophyte formation” (Bennell, Poquet, Williams, 2016, P. 1689). These signs prove detrimental for some individuals who begin to suffer severe pain leading to the inability of performing simple tasks such as writing and/or walking. Hip disabilities are especially common as a result of osteoarthritis, leaving individuals with several choices of treatment. Whether it’s physical therapy, exercise, or taking medicine, these options might not prove helpful depending on the severity of the hip joint. In this essay, I will be comparing minimally invasive hip replacement to traditional hip replacement to determine why someone need’s a hip replacement procedure, which option more favorable, and the physical therapy following post-replacement.
The two actuators have different actuation voltages, power consumption, response time1, and force output4. Electrostatic actuators have a high actuation voltage, low power consumption, and a fast response time. On the other hand, thermal actuators have a low actuation voltage, high power consumption and a low response time1. Compared to the electrostatic actuators, the thermal actuators are able to generate forces that are three orders of magnitude higher, higher forces making it easier to move the electrode within tissue4. Due to the nature of the devices with movable electrodes in which these actuators are being used, it is difficult to make the space around the actuators hermetically sealed, allowing for moisture to get inside. This can pose a problem since enough moisture can interfere with the actuation of both types of actuators. Another advantage that the thermal actuators have over the electrostatic ones is that the thermal actuators are able to better handle the mechanical vibrations that are present during chronic implantationn4. One disadvantage of using thermal actuators in implantable devices is the fact that the actuators themselves can heat up to several hundred degrees Celsius. While the temperature only remains that high for a few hundred milliseconds and only a few microns from the actuators4, if the actuators are actuated at a high enough frequency, this can lead to a sustained high temperature of over one hundred degrees Celsius, which can lead to tissue damage if implanted into the
The recent push for approval of silicone implants is particularly problematic. Doctors and patients often prefer the silicone implants because they more closely mimic the look and feel of breast tissue ((1)). Although there is little evidence supporting the claims made against silicone breast implants in the 1980's (which said that they contributed to autoimmune and connective tissue disorders), it can be said that silicone implants cause more problems than saline implants. When a saline implant ruptures, it deflates almost immediately, creating visible evidence of the problem ((1)). Silicone implants may show symptoms of rupturing, but many women have a "silent rupture" in which the scar tissue around the implant holds in the saline gel. Since these women have no symptoms, the only way to identify the rupture is through MRI ((5)). What makes this particularly alarming is that the long term effects of having the silicone gel sitting indirect contact with scar and breast tissue is unknown, which is one of the reasons that the chairman of the FDA advisory panel, which voted in favor of approving silicone implants, asked that the FDA ignore the panel's advice ((6)). Long term safety of silicone implants has simply not been demonstrated by any studies presented to the FDA, yet many in the
Despite contrary belief, hip replacement is not necessarily negative. Many Americans believe that in order to have a hip replacement, your condition must be terrible. A survey conducted in 2012 said that almost 1/3 of respondents to the hip replacement survey felt they would have benefited from having their surgery done earlier. This procedure has and continues to change the lives’ of many people in our world. Hip replacement, or arthroplasty, is a surgical procedure in which the diseased parts of the hip joint are removed and replaced with new, artificial parts. These artificial parts are called the prosthesis. The goals of hip replacement surgery include increasing mobility, improving the function of the hip joint, and relieving pain. According to the Centers for Disease Control and Prevention, 332,000 total hip replacements are performed in the United States each year. “Hip Replacement.” Questions and Answers about. N.p., n.d. Web. 21 Oct. 2013.