Medicosnext
Time has its own anatomy for humans. No one escapes from this naturally laid framework, especially with aging. One of the most common ravages of age is knee disease. Over time, the wear-and-tear of routine life takes a toll on one’s cartilage, the natural cushioning of knee bone. Once the cartilage starts deteriorating, the joints start to become painful and stiff, thus affecting joint movement and limiting performance of activities. One might feel significantly affected with this, as you lose your ability to move as painlessly and fluidly as before. It has a depressing impact on your mind and your quality of life.
But, we live in an era where technological advances and marvels of science are abundant, and in a sense, seamless. These advancements have facilitated best treatment options for almost every disease, including painful knees. The keyword here is, ‘knee replacement’.
What is knee replacement?
Knee replacement is one of the most common bone surgeries to resurface and treat a damaged knee. Also known as knee arthroplasty, which actually means surgical repair of a joint, knee replacement surgery reconstructs and replaces the degenerated joints using prosthetics or artificial body parts.
In clinical anatomy, a knee is a modified hinge joint, which allows motion through extension and flexion, along with required amount of internal as well as external rotation. The knee is formed of three bone types, viz. tibia, femur, and patella. To ensure limited friction, these bones are covered with a fine layer of cartilage. Meniscus forms the lateral and medial sides of the tibial plateau, which works as a shock absorber. All the three bones are retained together by ligaments and surrounded by a capsule.
Composition of a knee
• Tibia: shin bone or large bone of the lower leg
• Femur: thighbone or bone of upper leg
• Patella: kneecap
• Cartilage: a type of tissue covering the bone’s surface at a joint
• Ligament: tough and elastic connective tissue surrounding the joint
• Meniscus: curved part of the cartilage in a knee, acting as a shock absorber
• Tendon: tough tissue connecting muscles to bones and aiding in control of joint movement
• Synovial membrane: tissue which lines the joint and seals it into the capsule
When all these components of the knee are damaged or distressed, knee replacement becomes vital and necessary. This surgery can help to relieve pain and restore functioning of severely damaged knee joints, thereby disabling osteoarthritis of the knee.
When and why is knee replacement necessary?
Knee replacement surgery is needed when a knee joint has been worn out or damaged extensively, causing reduced mobility and acute pain. One of the most common causes to undergo knee replacement is osteoarthritis, a chronic condition in which the cartilage breaks down, leading to severe damage. Symptoms associated with osteoarthritis are: pain in joints, stiffness, limited movement and mobility, swelling of the joint, or even deformity.
Experts would suggest a person to undergo knee replacement if they suffer from the following:
• Pain in the knee, which comes on with performing any activity and limits the person to undertake the activity further.
• Pain in the knee after performing an activity, also known as delayed pain.
• Knee pain, preventing the person to sleep, or at times, wakes up the person due to the pain caused by movements during sleep.
• Changes in the appearance of the knee: inflammation, swelling, or stiffness.
• Difficulty in movement, especially in bending the knee, for example, sitting down on a low seat in a car or couch.
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Knee replacement is also strongly suggested and recommended by experts in case of patients diagnosed with rheumatoid arthritis or psoriatic arthritis. In some cases, gout, unusual bone growth, death of a bone in knee joint, knee injury, or knee deformity can also cause the patient to undergo knee replacement.
Studies have shown that two-thirds of the patients opting for knee replacement surgeries have degeneration in both the knee joints. Furthermore, it has also been observed that patients undergoing knee replacement in one knee will opt to undergo the same for the second knee within just two years after replacement of the first knee.
In case of patients diagnosed with bilateral knee disease, they can opt for undergoing one-stage surgical procedures for both the knees, which means, surgery for both knees can be performed at the same time. It is also possible to perform knee replacement for both knees in two separate surgeries, ideally at the same hospital, or by the same surgeon, in a time frame of 1 to 12 months.
Types of knee replacement surgeries
Total knee replacement
Traditionally, one of the most common types of knee replacement is the total knee replacement, commonly referred to as TKR. In TKR, the articular surfaces of a knee joint, viz. femoral condyles and tibial plateau, are replaced. The implants, or the replacements, are of several types, which are made of cobalt, titanium, chrome, and polyethylene (plastic). The implants can be fixed to the bone with acrylic cement or press-fit, enabling the bone to grow within the fitted implant.
In this kind of surgery, a strong and polished metal alloy replaces the femur portion of the knee. Similarly, the tibia is replaced by a strong and durable polymer tray, while the patella is replaced by a plastic prosthetic joint; thus removing the damaged cartilage and the bone.
Partial knee replacement
In a situation where only one part or compartment of the knee is damaged and is required to be replaced, rather than the whole joint, partial knee replacement is performed. In this type of surgery, implant is surgically inserted for either tibia, femur, or patella portion through a smaller incision. Such surgeries require very less hospital stay, sometimes just overnight.
Minimally invasive knee replacement
This type of surgery is garnering a lot of attraction and appreciation in recent times. The newer minimally invasive knee replacement (MIS) uses specialized techniques to reduce the standard incision of 8-12 inch to 3-5 inch. This facilitates recovery with lesser scar tissue formation, reduced pain, and quick healing period.
Right time for knee replacement
Ideally, there is no defined age or weight restriction or suitability associated with undergoing knee replacement. Widely, surgeons and experts recommend knee replacement surgeries based on the knee pain and disability of the patients, irrelevant of their age. It is, however, observed that the world over, majority of individuals opting for knee replacement surgery are between 50 and 80 years of age.
In some cases, TKR has also been performed on young people (below the age of 50) and even teenagers suffering from juvenile arthritis or severe injuries. Studies have shown that more than 95% of knee replacements in this patient age-group were functioning even 10 years after the implants.
Benefits of knee replacement surgery
It has been researched that more than 90% of those who have undergone any type of knee replacement surgery experience a significant reduction in knee pain, which enables them to efficiently perform activities of their choice, in addition to normal, day-to-day activities. Given below are specific benefits of undergoing knee replacement surgery.
• Pain relief: Knee replacement surgery brings significant pain reduction, and thus provides relief to the patients affected with knee-related diseases.
• Improved mobility: Research has shown that 90% of the patients who have undergone knee replacement have been able to overcome mobility barriers, which affected them prior to the surgery. This includes walking, jogging, swimming, cycling, and performing day-to-day activities, as well.
• Improved quality of life: Knee pain or deformity often puts a person’s lifestyle on sudden hold, where one feels depressed and distressed because of the limitations due to acute pain in the knees. After undergoing knee replacement, patients feel motivated and optimistic, as they are able to commute and undertake activities smoothly and painlessly. This creates a positive impact on the overall quality of life.
Knee replacement surgery in India
India has excellent state-of-the-art hospitals for knee replacement surgery. These hospitals have the best-suited infrastructure and abundant resources for conducting knee replacement surgeries, not just for Indian patients, but also for numerous ailing patients worldwide. This is visible from the figures collected in 2017 with regard to patients traveling to India from top 15 countries for knee replacement surgeries.
India is best-suited for knee replacement surgery because of the low cost of surgery, establishment of speciality hospitals, and tourism options, as well. The top hospitals for knee replacement surgery in India are located in Delhi, Mumbai, Ahmadabad, Chennai, Bengaluru, Noida, and Hyderabad, to name a few. These hospitals are equipped with the latest technology, which uses minimal invasive techniques to reduce pain and ensure faster recovery. Knee replacement surgeons in India have extensive subject knowledge and vast experience in conducting the surgeries, and are accredited by national as well as international agencies and medical institutions across the globe.
Noteworthy developments in knee replacement
Knee replacement has come a long way since the mid-1800s, when a German surgeon named Themistocles Gluck imagined crafting hinge joints made of ivory! Talking about the reported and published facts, knee replacement surgeries are being performed since many decades, with the first surgery being done in 1968. Since then, modern techniques and advancements in surgeries have evolved; opening a new chapter in high-performance and focused knee implants, the most recent being minimally invasive surgery (MIS). Here are some of the noteworthy developments and contributions made by specialists and experts of knee replacement.
• One of the most significant technologies is computer-navigated TKR surgery. This type of surgery uses specialized software, infrared camera, and trackers. While performing this surgery, the trackers are attached to the patient’s knee, which then transmits specific data to the infrared camera. Making use of this data, the surgeon designs the surgery by planning the bone cuts, customizing knee implant position, and inserting the artificial joint accurately. This kind of surgery was first performed in France two decades ago; and since then, it has undergone extensive up-gradation.
• ConforMis, a medical technology company based in Billerica, MA, combines advanced 3D imaging technology with latest manufacturing potential to design and produce a unique implant for each of the ailing patients. The company uses its proprietary iFit Image-to-Implant technology to develop and manufacture these replacement implants, which are shaped and sized separately for each individual. Their iTotal CR, a cruciate-retaining TKR implant, has demonstrated significant outcomes and greater patient satisfaction ratio.
• Assistant Prof Sherry Towfighian of Binghamton University, USA, led a team of researchers as the principal investigator to conduct a study on ‘Smart Knee Implants’. According to Towfighian, they are working on a knee implant that will have built-in sensors that can monitor the amount of pressure being put on the implant. These sensors will enable the doctors to determine which movement of the patient’s knee is causing damage or impact on the implant. This will enable them to advise the patient to adjust accordingly, thus avoiding more damage to the implant. It is said that these implants will not only help the specialist doctors and surgeons, but will also aid the researchers in developing more effective implants in the future. The research, conducted with the support of National Institute of Health, was published in the journal Smart Materials and Structures.
• Jeffery C Davis, MD and orthopaedic surgeon at Andrews Sports Medicine & Orthopaedic Centre, Birmingham, AL, utilizes ‘MRI-specific Cutting Guides’ which aid in expediting the surgery, in addition to enhancing accuracy and minimizing blood loss.
• Surgeons at the Ohio State University’s Wexner Medical Centre have just completed successful implant of ‘Calypso’; a shock absorber that protects the knee, relieves pressure, and acts in a similar way to cartilage, providing a cushioning to the joint.
Summary
Knee replacement is a reliable surgery that relieves the patient from pain caused by arthritis or injuries by replacing the damaged component with implants. After the surgery, the patient feels steep substantial decline in the pain and increased mobility; thus feeling more active, comfortable, and motivated. Certain risks are associated with this surgery, as in case of any other major procedure, but knee replacement is definitely a good quality-of-life decision. While advancements in techniques, coupled with research and development, have almost eliminated the risks associated with these surgeries, we should be hopeful that in the near future, more effective, less time-consuming, and quick recovery techniques of knee replacement will be made available to the people around the globe.
