Osteoarthritis is the most common form of arthritis that affects the knee. In this condition, the slippery cartilage that covers the ends of bones in knee joint wears down. This video also explores a treatment option called a fixed knee replacement.
over 5 years ago
So you're sitting in a bus when you see a baby smile sunnily and gurgle at his mother. Your automatic response? You smile too. You're jogging in the park, when you see a guy trip over his shoelaces and fall while running. Your knee jerk reaction? You wince. Even though you're completely fine and unscathed yourself. Or, to give a more dramatic example; you're watching Titanic for the umpteenth time and as you witness Jack and Rose's final moments together, you automatically reach for a tissue and wipe your tears in whole hearted sympathy ( and maybe blow your nose loudly, if you're an unattractive crier like yours truly). And here the question arises- why? Why do we experience the above mentioned responses to situations that have nothing to do with us directly? As mere passive observers, what makes us respond at gut level to someone else's happiness or pain, delight or excitement, disgust or fear? In other words, where is this instinctive response to other people's feelings and actions that we call empathy coming from? Science believes it may have discovered the answer- mirror neurons. In the early 1990s, a group of scientists (I won't bore you with the details of who, when and where) were performing experiments on a bunch of macaque monkeys, using electrodes attached to their brains. Quite by accident, it was discovered that when the monkey saw a scientist holding up a peanut, it fired off the same motor neurons in its brain that would fire when the monkey held up a peanut itself. And that wasn't all. Interestingly, they also found that these motor neurons were very specific in their actions. A mirror neuron that fired when the monkey grasped a peanut would also fire only when the experimenter grasped a peanut, while a neuron that fired when the monkey put a peanut in its mouth would also fire only when the experimenter put a peanut in his own mouth. These motor neurons came to be dubbed as 'mirror neurons'. It was a small leap from monkeys to humans. And with the discovery of a similar, if not identical mirror neuron system in humans, the studies, hypotheses and theories continue to build. The strange thing is that mirror neurons seem specially designed to respond to actions with clear goals- whether these actions reach us through sight, sound, smell etc, it doesn't matter. A quick example- the same mirror neurons will fire when we hop on one leg, see someone hopping, hear someone hopping or hear or read the word 'hop'. But they will NOT respond to meaningless gestures, random or pointless sounds etc. Instead they may well be understanding the intentions behind the related action. This has led to a very important hypothesis- the 'action understanding' ability of mirror neurons. Before the discovery of mirror neurons, scientists believed our ability to understand each other, to interpret and respond to another's feeling or actions was the result of a logical thought process and deduction. However, if this 'action understanding' hypothesis is proved right, then it would mean that we respond to each other by feeling, instead of thinking. For instance, if someone smiles at you, it automatically fires up your mirror neurons for smiling. They 'understand the action' and induce the same sensation within you that is associated with smiling. You don't have to think about what the other person intends by this gesture. Your smile flows thoughtlessly and effortlessly in return. Which brings us to yet another important curve- if mirror neurons are helping us to decode facial expressions and actions, then it stands to reason that those gifted people who are better at such complex social interpretations must be having a more active mirror neuron system.(Imagine your mom's strained smile coupled with the glint in her eye after you've just thrown a temper tantrum in front of a roomful of people...it promises dire retribution my friends. Trust me.) Then does this mean that people suffering from disorders such as autism (where social interactions are difficult) have a dysfunctional or less than perfect mirror neuron system in some way? Some scientists believe it to be so. They call it the 'broken mirror hypothesis', where they claim that malfunctioning mirror neurons may be responsible for an autistic individual's inability to understand the intention behind other people's gestures or expressions. Such people may be able to correctly identify an emotion on someone's face, but they wouldn't understand it's significance. From observing other people, they don't know what it feels like to be sad, angry, surprised or scared. However, the jury is still out on this one folks. The broken mirror hypothesis has been questioned by others who are still skeptical about the very existence of these wonder neurons, or just how it is that these neurons alone suffered such a developmental hit when the rest of the autistic brain is working just dandy? Other scientists argue that while mirror neurons may help your brain to understand a concept, they may not necessarily ENCODE that concept. For instance, babies understand the meaning behind many actions without having the motor ability to perform them. If this is true, then an autistic person's mirror neurons are perfectly fine...they were just never responsible for his lack of empathy in the first place. Slightly confused? Curious to find out more about these wunderkinds of the human brain? Join the club. Whether you're an passionate believer in these little fellas with their seemingly magical properties or still skeptical, let me add to your growing interest with one parting shot- since imitation appears to be the primary function of mirror neurons, they might well be partly responsible for our cultural evolution! How, you ask? Well, since culture is passed down from one generation to another through sharing, observation followed by imitation, these neurons are at the forefront of our lifelong learning from those around us. Research has found that mirror neurons kick in at birth, with infants just a few minutes old sticking their tongues out at adults doing the same thing. So do these mirror neurons embody our humanity? Are they responsible for our ability to put ourselves in another person's shoes, to empathize and communicate our fellow human beings? That has yet to be determined. But after decades of research, one thing is for sure-these strange cells haven't yet ceased to amaze and we definitely haven't seen the last of them. To quote Alice in Wonderland, the tale keeps getting "curiouser and curiouser"!
over 7 years ago
Knee injuries are common and of emergency appartment acute injury admissions, the knee is the joint most often affected. This talk focuses on the injuries most often experienced by professional sportsmen. It provides an interesting environment from which to learn about injuries we are all likely to see if we work in A+E. The talk covers knee anatomy, common signs and symptoms of knee injuries, how to examine the knee and general management of the injuries.
over 10 years ago
The largest and longest bone in the human body is the femur, and it is located in the upper leg. The femur connects to the knee at one end and fits into the hip socket at the...
over 5 years ago
Although used less commonly than knee or hip replacement, shoulder replacement surgery removes diseased or damaged bone in the shoulder and replaces it with an artificial joint. If arthritis pain is unrelieved by other methods, you may need replacement surgery.
over 5 years ago
Orthopedic surgeons at Baptist Medical Center in Jackson, Miss., are among the first in the Metro Jackson area to use computers to help pinpoint perfect alignment…
over 6 years ago
Kaleb Michaud, Ph.D., has for a long time listened to patients with rheumatoid arthritis (RA) talking about improved quality of life after their total joint replacements.
about 6 years ago
Review of orthopaedic services: Prepared for the Auditor General for Scotland. March 2010. Website http://www.audit-scotland.gov.uk/media/article.php?id=128 "In recent years, the National Health Service (NHS) in Scotland has significantly reduced the length of time people are waiting to receive orthopaedic procedures such as hip replacements and knee operations. Over 95% of patients are now treated within 26 weeks of referral, compared to only 66% in 2003. But there is scope to make savings by working more efficiently. An Audit Scotland report, Review of orthopaedic services, says there is high demand for these services. Orthopaedic care is particularly important for older people, who have the highest rates of fractures and joint replacement."
over 11 years ago
A 54 year old man presented to his general practitioner because of a fullness in his left lateral thigh that he first noticed while playing golf, although it was not related to an identifiable injury. He had a history of hypertension and fibromyalgia and was taking atenolol, ramipril, pregabalin, and tramadol but was otherwise well. The GP thought that the swelling was caused by a muscular injury, but the patient re-presented four months later because the mass had grown from a small bump to a swelling of 8 cm in diameter. It was also beginning to cause some knee stiffness but no pain. On examination he had a large firm swelling in his lateral thigh. On this occasion his GP referred him on a two week wait to the regional plastic surgery department. An ultrasound scan showed a 6 × 8 cm intramuscular mass with cystic changes and patchy neovascularity, but no inguinal or pelvic lymphadenopathy. Ultrasonography was followed by magnetic resonance imaging, with and without gadolinium contrast (fig 1⇓).
over 7 years ago
Anterior knee pain is common in children and adolescents. Evaluation and management is challenging and requires a thorough history and physical exam, and understanding of the pediatric skeleton. This article will review common causes of chronic anterior knee pain in the pediatric population with a focus on patellofemoral pain.
almost 6 years ago