Typical hospitalization times usually range from three to four days for most total knee replacement surgeries, with the partial (unicondylar) knee replacement patients usually needing less time in the hospital (usually two or three days). The events leading up to and surrounding the surgery are similar for all joint replacement surgeries and are detailed in a later chapter, including information about preoperative testing, blood donation, anticoagulation, etc.
In general, most of the patients treated in our practice can expect a general timeline similar to the one presented here, although there certainly can be variability depending on other medical issues and the exact type of surgery performed.
Day of Surgery
Most patients arrive at the hospital early on the morning of total and partial knee replacement surgeries. This process is detailed in a later chapter because the process is the same for both hip and knee replacement surgeries. The surgery usually takes about 60 to 90 minutes for routine primary (first time) surgeries, although it certainly can take longer if the patient has had prior surgery, is very muscular or obese, is having more than one procedure performed, etc. In our practice, partial knee replacements tend to take about 20 to 30 minutes less than a total knee replacement.
The time in the operating room for most surgeries is actually longer than the time needed for the procedure itself, because the anesthesiologist needs time to perform the spinal or general anesthesia, the patient needs to be positioned and prepped with antiseptic scrub, and sterile drapes have to be placed.
Most patients are in the recovery room for two or three hours after the surgery, at which time routine xrays are taken to check on the implants and surrounding bones. Patients also need to be fully awake and have a stable blood pressure before being transferred to their hospital room upstairs. However, many knee replacement surgery patients can actually get up with assistance that first evening, just to stand or take a few steps.
After Surgery
Physical therapy starts in earnest on the second day of hospitalization. Most patients are allowed to fully bear weight on the affected knee (or knees, if both were replaced at the same time), but it is important to work with the physical therapist to ensure that there is no dizziness from medications or anesthesia. We typically allow most patients to fully weightbear right away if the postoperative x-rays show everything to be in good position and there are no special circumstances. Most surgeons (as in our practice) prefer to start full weightbearing as soon as possible, as this has been demonstrated to have a positive effect on recovery. Your surgeon and physical therapist will let you know your weightbearing status after surgery.
Most patients use a walker at first, and when they are ready and steady enough, they progress to a cane. There is a great deal of variability in how long the process takes, because everyone has different levels of physical stamina, balance, muscle strength, etc. As a general rule, younger and more active patients and thinner patients will graduate to using a cane quicker than their older or heavier counterparts. Patients who have had surgery on just one leg will progress more quickly than patients who have had both knees operated on.
Most IV lines, urinary catheters (if you have one - not all patients require this), and surgical drains (again, if you have one) are removed on the first or second day after surgery. Most of our patients do not have any drains, but they are occasionally employed depending on the size of the patient and surgical factors. Although many patients may be apprehensive about removal of drains or catheters, most are somewhat surprised to find that this is not usually as uncomfortable as they expected and literally takes only seconds.
There are typically daily blood tests to monitor hemoglobin levels and metabolic parameters, and patients are monitored to make sure that they do not have any complications after surgery such as a blood clot or a serious hematoma (more on this later). Blood thinners of some sort (either aspirin, heparin / enoxaprin injections, or warfarin) are usually started the day after surgery also (the exact regimen depends on the patient, surgeon, and medical factors). In our practice, enoxaprin injections are usually used for several weeks after significant knee surgery to prevent blood clots.
In contrast to total hip replacement patients, who have a list of precautions to follow so that the hip does not dislocate in the initial weeks while the soft tissues are healing, knee replacement patients are limited more by their stamina and ability to move on their own. Nearly all knee replacement patients are allowed to place full weight on the knee right away (unless there are special circumstances, such as a fracture), and knee replacements do not have the risks of dislocation that a hip replacement presents. One of the primary concerns with knee replacements is stiffness in the weeks and months after surgery, and for this reason range of motion exercises are extremely important. The physical therapist works with you to practice your recommended exercise regimen and learn what you should and should not do after leaving the hospital.
Some surgeons and hospitals employ an automated machine called a continuous passive motion (CPM) machine, which is a mechanized cradle that fits under the leg and slowly bends the knee back and forth while the patient is in bed. There are pros and cons to using such a device, and in general, most surgeons would agree that working with a physical therapist or nurse is a better work out for the knee. Additionally, we would prefer that the knee muscles are actively moving if possible. CPM machines are frequently used when a patient is either unable to get up and fully participate because of other medical issues or when there is a less than optimal amount of physical therapy time and therapists available.
Leaving The Hospital
After two to three days, most partial knee replacement patients are typically ready to graduate to home with visiting nurses and therapists. Discharge to a rehabilitation facility is not as common for partial knee replacements as it is for total knee and hip replacement patients, although sometimes there are physical or social factors that make a short stay at a rehabilitation center a good idea. Common reasons may include having both knees operated on, very large patient size, patients who live by themselves, or other related factors.
After three or four days, most total knee replacement patients are ready to graduate either to home with visiting nurses/physical therapy or to a short term rehabilitation facility. This depends on how well the patient is able to get around on their own and their age, but most often the need for a rehabilitation center is dependent on social factors. If a patient lives alone or does not have adequate help, or if the living arrangements cannot be changed to accommodate staying on one level, then a short stay at a rehabilitation center is more likely.
Post-operative Visits
The first post-operative visit is usually between 3 and 6 weeks after surgery. If there are staples or nonabsorbable sutures, these are usually removed by the visiting nurse at 2 weeks after the surgery. Patients are discharged with a detailed list of instructions on what to do, what not to do, and what to call about (such as fevers, wound breakdown, calf swelling, etc.). These are described in greater detail in a later chapter.
Please remember the information on this site is for educational purposes only and should not be used to make a decision on a condition or a procedure. All decisions should be made in conjunction with your surgeon and your primary care provider.
