A total knee replacement (TKR) implant typically adds about 0.6 to 1 pound (270 to 450 grams) of weight to the knee joint, as studies show the implant and cement are heavier than the bone and tissue removed, with average weight gain around 290-450 grams depending on the study and patient's body, though some implants are lighter. This slight increase in local weight, combined with post-surgery pain and inflammation, often causes the sensation of a "heavy" feeling in the knee during recovery.
The approximate mean knee replacement weight limit of the new knee (plus the cement used) is 509 grams (1.12 pounds) for men and 345.5 grams (0.76 pounds) for women. The weight of an individual knee implant may vary depending on the specific requirement.
Most patients gain weight in the 2 years after total knee arthroplasty: comparison to a healthy control group - PMC.
Two main themes were identified: 1) when describing chronic postsurgical pain, some participants also described sensations of discomfort, including heaviness, numbness, pressure, and tightness associated with the prosthesis; 2) participants reported a lack of felt connection with and agency over their replaced knee, ...
Implants used for knee replacements are on average 0.6 lbs heavier than a natural knee.
Stratification of patients by pre- and post-operative body mass index. Postoperative analysis showed a decrease in weight in 41 patients (46%) and weight gain in 50 (54%). Mean postoperative BMI was 27.16 kg/m2; overall, a slight decrease of 0.08 kg/m2 was observed.
While 90% were satisfied with the function of their new knee, about one-third reported that their knee did not feel "normal." Up to one half reported at least some continued symptoms or trouble with function.
Here are some of the most common types of pain patients may encounter during recovery from knee surgery:
Note: Side sleeping is usually an option several weeks into recovery, not immediately after surgery. Always check with your physical therapist or surgeon before trying this position.
Discussion. Numerous reports have noted that not all patients are satisfied after their primary total knee replacement with only 82–89% expressing satisfaction [2, 9, 11, 12, 14, 22, 23, 26].
Post-surgical knee stiffness, often referred to as “arthrofibrosis,” is one of the most reportedissues following procedures such as total knee replacement or ACL reconstruction. It occurs when scar tissue forms around the knee joint, restricting your range of motion.
As with any surgery, knee replacement does carry risks. Some potential complications include: Infection: Though rare, post-surgical infections can occur and may require additional treatment. Blood Clots: Patients are at risk for blood clots in the leg following surgery, which need careful management.
A reasonable goal for maximum bend after knee replacement is at least 120 degrees — the range of motion that allows patients to get in and out of a car or ride a bike. However, patients may reach around 115 degrees at this stage.
Superior Strength-to-Weight Ratio
Titanium knee implants are strong but light. This helps the bone and tissue around the knee. This is key for quick recovery and lasting results.
Most of the knee replacement designs require the removal of the ACL, even if, as shown by our study, the majority of patients still have this ligament intact.
After knee replacement, regular exercise is encouraged. However, patients should avoid heavy lifting and high-impact exercise and sports. That means no more jogging or basketball and no lifting more than 50 lbs.
Weeks 3 to 6 After Total Knee Replacement
Around four to six weeks, many people can climb a flight of stairs more smoothly using the railing, and some can do so without a walking aid. Others may still use a cane or take one step at a time, which is also normal.
Proper walking is the best way to help your knee recover. At first, you will walk with a walker or crutches. Your surgeon or therapist will tell you how much weight to put on your leg. Stand comfortably and erect with your weight evenly balanced on your walker or crutches.
Most patients use controlled pain medications for the first four weeks after surgery. Opioid alternatives, like iovera®, can also improve post-operative pain after knee replacement. By six weeks after surgery, most patients can stop controlled pain medications.
These medications reduce inflammation and relieve pain. Examples of NSAIDs include diclofenac, ibuprofen and naproxen. Two other anti-inflammatory painkillers with a similar effect are celecoxib and etoricoxib. These are COX-2 inhibitors (also known as coxibs).
New parts are fitted over the ends of both bones to create the new joint. The parts are usually made of metal and plastic. Some people may also have the back of the kneecap replaced with a new part. The kneecap is put back into place.
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Knee replacement surgery is generally recommended in more advanced stage 3 or stage 4 osteoarthritis of the knee.
The #1 mistake making bad knees worse is excessive rest and a sedentary lifestyle, leading to weaker supporting muscles, stiffness, and a vicious cycle of more pain; instead, gentle, consistent movement (like walking, swimming) is crucial to strengthen the joint and improve function, though it must be balanced with avoiding activities that cause sharp pain. Other major errors include ignoring pain signals, carrying excess weight, wearing unsupportive shoes, and poor movement patterns, says Parkside Sports Physiotherapy and Coastal Empire Orthopedics.