Jess Lonner, MD

About Dr. Lonner Am I a Candidate? About Knee Surgery What and When Can I? Before, During and After Surgery Is it Normal?

Patients often have questions about knee replacement surgery. This section highlights many of the frequently asked questions and common responses that we may give to those questions. We encourage you to ask us any question you'd like about knee replacement surgery. (This section is intended for educational purposes. It is not meant to substitute for the consultation with Dr. Lonner and the professional associates in the practice.)


About Dr. Lonner

1. Does Dr. Lonner only perform Minimally Invasive Knee Replacement Surgery?
   

   In Dr. Lonner's practice, while approximately 90% of patients are candidates for minimally invasive total knee replacement surgery, some will be treated with a traditional approach. This decision is based upon a variety of factors including size of the limb, ligament stability, deformity, scarring, and prior trauma. Generally, Dr. Lonner's unicompartmental, patellofemoral, and bicompartmental replacements are performed with minimally invasive approaches unless there are unique situations which preclude that opportunity.

2. Why don't all doctors use minimally invasive approaches or perform partial knee replacements given the results that you promote?

   Unlike Dr. Lonner, not all surgeons are comfortable operating through smaller incisions or have observed improvements in outcomes with minimally invasive techniques. Dr. Lonner has spent years refining the techniques of minimally invasive total and partial knee replacement surgery and in his experience, the results of these procedures have been highly satisfying both for his patients and his team.

Am I a Candidate?

3. How do I know if I am a candidate for a total knee replacement or a partial knee replacement?

   The decision regarding whether you will receive a total knee replacement, or unicompartmental, patellofemoral, or bicompartmental resurfacing is made after an analysis of your particular pattern of arthritis and location of knee pain, and only after having had a discussion with you about your activity levels and expectations. Dr. Lonner uses the option of resurfacing only those compartments of the knee that are arthritic because it is a more conservative approach than total knee replacement. And while many patients with knee arthritis are in fact only candidates for a total knee replacement, others (approximately 20% of knee replacement candidates) have localized arthritis, good ligament stability, and minimal deformity, making them ideal candidates for the various partial knee replacements.

4. Am I a candidate for the knee replacements made specifically for females?

   The lower part of the thigh bone (femur) is shaped differently in women than men. There have been some recent implant design modifications in both total knee and patellofemoral replacements that accommodate these differences and allow us to better fit the implant to our female patients. Generally, Dr. Lonner uses these implants in his female patients unless there are unusual and extraneous circumstances that he would discuss with you prior to surgery.

5. I am young; can I still have a total knee replacement?

   The average age of our patients undergoing knee replacement surgery has decreased considerably over the last decade, as our confidence in the procedures has grown and "baby boomers" present more frequently with advanced arthritis. While there may be alternatives for extremely young patients with arthritis such as cartilage transplantation or bone realignment, knee replacement surgery may provide the most predictable and effective solution, even if you are young. Additionally, Dr. Lonner may discuss the possibility of a partial knee replacement as a bridging procedure before an eventual need for a total knee replacement. Many middle-aged patients see Dr. Lonner for partial and total knee replacement surgery.

About Knee Surgery

6. How long does it take to perform knee replacement surgery through a minimally invasive approach?

   Typically, knee replacement surgery will take between 45 and 90 minutes, depending on the complexity of the case and challenges that are encountered during surgery. Evolving and innovative techniques may require additional time.

7. How much does a total knee replacement weigh?

   A typical total knee replacement weighs approximately ¼ pound. Revision implants weigh more; partial knee replacement implants weigh considerably less.

8. Do you perform knee replacement surgery on both knees under the same anesthetic?

   The majority of patients have one knee replaced at a time but approximately 15% of Dr. Lonner's patients will undergo bilateral (both knees) surgery. This decision is made depending on the severity of painful arthritis in the knees and the presence of deformity. Occasionally, leaving a severely deformed limb untreated will compromise the rehabilitation and outcome of the replaced or resurfaced knee; therefore, at times Dr. Lonner will advocate that the patient have both knees replaced during the same anesthetic setting. The duration of recovery is not doubled when both knees are replaced; however, it is slightly lengthened compared to unilateral (one side) surgery. Some patients will opt to have both knees replaced simultaneously if they want to minimize overall time off from work, since replacing both knees simultaneously will reduce the overall duration of time off from work compared to the sum of time if they come in for two hospitalizations to have each knee replaced separately. There are some increased medical risks (particularly cardiac and pulmonary) associated with bilateral simultaneous knee replacement surgery; therefore the option of having both knees replaced simultaneously is often reserved for patients who are relatively young and healthy.

9. How long will my knee replacement last?

   Both partial and total knee replacements are durable -- we expect that approximately 90% will last ten to fifteen years. Some implants will begin to fail at various stages because of wear, loosening, or other reasons. Newer implant designs and bearing surfaces, and improved accuracy provided by contemporary techniques, such as robotic-assisted techniques, may enhance the long-term success of knee replacement surgery. But there is no guarantee that the implant will last the rest of your life. If you place undo stress on the implant, it can fail sooner. Dr. Lonner will discuss what activities would be appropriate after knee replacement, the signs and symptoms that may signify that your implant may be failing, and what will need to be done if your implant loosens or wears out.

10. What are the risks of partial and total knee replacement surgery?

    In general, complications occur infrequently after knee replacement surgery. However there are anesthetic and medical risks, as well as those related to the knee replacement surgery. The anesthesiologist will speak to you about the specific risks of anesthesia. The medical consultant that sees you preoperatively will review medical risks, but generally these include cardiopulmonary (heart and lung) problems, blood clots, pulmonary embolism, urinary tract infection, stroke - all of which are uncommon. The risk of death within thirty days after surgery is approximately one-tenth of one percent. Surgical risks include eventual loosening or wear (6-10% within 10-15 years), infection (less than 1% in Dr. Lonner's practice), bleeding, pain, fracture, tendon or ligament injury, nerve or blood vessel injury, limb lengthening, stiffness, instability, numbness, weakness, implant breakage, swelling, blisters, and wound breakdown. In the case of partial knee replacements, since only a portion of the knee is resurfaced with the artificial components, the joint can become painful if arthritis develops in the remaining compartments of the knee or if a ligament or meniscus tear occurs. If you have a total knee replacement, you cannot develop further arthritis in the knee. Refer to the section on Risks of Knee Replacement Surgery for additional details.

What and When Can I?

11. What activities can I expect to do after knee replacement surgery?

    The purpose of the knee replacement is to allow you to resume activities that you had enjoyed before the onset of pain and debilitating arthritis. With this in mind, however, you should avoid excessive running, jumping, or unusually strenuous activities after surgery. These activities can put undo stress on the implants, increasing the risk of discomfort, swelling and even premature loosening or wear of the components. Many of our patients typically can perform low impact aerobic activities such as biking, swimming, walking several miles, gentle hiking, golfing, doubles tennis, and yoga. Fifty percent of patients are unable to kneel after total knee replacement.

12. When can I walk independently?

    Initially in the hospital, you will be trained to ambulate with crutches or a walker and then be transitioned onto a cane as your balance and strength improve. Many patients who have unilateral (one side) surgery through a minimally invasive approach can get off their cane within two to three weeks after knee replacement surgery, whereas it may take up to 3 months to stop using a cane if you have a more traditional approach. Some patients, particularly those who are deconditioned or who have marked weakness of their quadriceps (thigh) muscles before surgery, may take six to twelve weeks until they can comfortably and safely transition off the cane. With the robotically assisted approach to unicompartmental knee replacement, some patients are off their canes as soon as 3 days after surgery

13. When can I drive?

    If you have had a right knee replacement, we typically recommend that you refrain from driving for six weeks after surgery, but this will vary from patient to patient. The important determinant of how soon you can drive is how easily you can move your foot from the gas pedal to the brake pedal without delay. When you feel ready to drive you should practice in a vacant lot with a family member or friend before transitioning to the roads. Presently Dr. Lonner is performing an investigation to evaluate when brake reaction times normalize after minimally invasive knee replacement surgery (in other words, we are studying whether patients can drive sooner with this surgical technique). If your left knee has been replaced, you should be able to drive as early as two weeks after surgery, as long as you are no longer taking narcotic medications. If you drive a car with standard transmission (a stick shift), you should likely wait 4-6 weeks. You can sit in a car as a passenger immediately after surgery, but frequent stops for long trips is advisable to minimize your discomfort; additionally, you should perform calf pumps and move your legs to help reduce the risk of a blood clot when you sit in a car for the first six weeks after surgery.

14. When can I fly after surgery?

    Many patients come from out-of-state or from other countries for surgery with Dr. Lonner; others, because of their new-found pain relief are eager to travel. In general, we suggest that you wait seven to ten days before flying. There is a slight increased risk of developing a blood clot while sitting for a prolonged period of time if you travel during the initial three months after knee replacement surgery, so you should use thromboembolic stockings (which we will prescribe) and frequently move your feet and ankles up and down during travel to help reduce the risk of a blood clot.

15. When can I shower?

    You can shower once the wound is dry, even if staples or sutures are still in place. Don't scrub the wound, and pat it dry; don't rub it.

16. Can I kneel?

    Studies have shown that there is likely no harm to the knee replacement if you kneel after knee replacement surgery. However, in several published series, approximately 50% of patients are able to comfortably kneel after any of the various types of knee replacements; others feel too uncomfortable or awkward to kneel. The use of a pad beneath your knee can make it easier for you to kneel.

17. When can I resume sexual activities?

    It is safe for you to resume sexual activities when you feel comfortable enough to do so. Make sure that your knee is not put in an awkward or uncomfortable position. Specifically, you should keep pressure off your knee while you are still recovering from surgery.

18. When can I cross my legs?

    Unlike hip replacement surgery, dislocating your knee replacement is unlikely to occur if you cross your legs. Therefore, after knee replacement surgery you can cross your legs, although you should wait six weeks from surgery when the risk of forming a blood clot in the veins of your leg is reduced. In theory, crossing your legs before the six week point can cause some compression of the veins in the back of your thigh, knee, or leg, increasing the risk of developing a blood clot.

19. When can I bathe or swim?

    Do not completely submerge your knee in water until three or four weeks after the surgical wound has completely healed. Swimming is a wonderful form of postoperative physical therapy.

20. When can I return to work?

    Your ability to return to work after a knee replacement depends on how quickly your pain improves, your ability to get around independently, and the job requirements. Some patients with sedentary (desk) jobs are able to return to work on a part-time basis as soon as one to two weeks after surgery, although most patients will require four weeks to return to a sedentary job and often they still have some discomfort. Therefore, you may wish to delay return to full time work for additional time. Patients who have more physically demanding jobs may need to be out of work for two to six months. Occasionally patients are advised to change jobs to less risky or strenuous positions. The robotically-assisted approach to unicompartmental replacement is enabling patients to return to work even sooner.

Before, During and After Surgery

21. What should I bring to the hospital?

    Essentials

    • A list of current medications and dosages
    • Insurance documentation
    • Documents requiring your doctor's signature
    • Identification
    • Eye
    • glasses
    • Nightgown/Pajamas
    • Robe
    • Comfortable clothing (sweatpants, loose shirts)
    • Slippers
    • Shoes
    • Toiletries
    • Book/Pen/Paper
    • Do not bring jewelry, watches or contact lenses



22. Is aquatic therapy of use before or after knee replacement surgery?

    Aquatic therapy is extremely useful both before and after knee replacement surgery. It is an excellent way to condition yourself, strengthen your muscles, and improve knee range of motion. The buoyancy provided by the water reduces stress and strain on the knee. After surgery you should refrain from submerging yourself in the water until several weeks after the staples are removed and the incision is completely healed, to avoid contamination of the surgical incision.

23. How long will I need to take antibiotics before dental work or other surgical procedures once I've had a knee replacement?

    You should take antibiotics before going to the dentist or having surgery for the rest of your life. Click here to see a list of antibiotics to take when you go to the dentist or have surgery. Click for List of Antibiotics

24. Will my leg be made longer and straighter as a result of total knee replacement surgery?

    Since arthritis destroys the cartilage that covers the knee joint, there is often a subtle loss of length of the affected limb. This can be even more pronounced when there is an associated deformity. Sometimes the deformity is very obvious, with marked bowing (outward or inward), and occasionally there is loss of full extension (meaning that you are unable to fully straighten your knee). Total knee replacement surgery not only restores the lost cartilage space but it also straightens the knee. This process generally makes the limb longer than it was immediately before surgery. The difference can be as as much as 2 centimeters (almost one inch), but on average the limb is lengthened between 5 mm and 8 mm (roughly one quarter of an inch). Unicompartmental and patellofemoral resurfacing are less likely to cause lengthening of the limb.

25. When do I begin physical therapy after knee replacement surgery?

    Your limb may be placed in a continuous passive motion machine (CPM) in the recovery room, which flexes (bends) and extends (straightens) your knee(s), although not all patients will receive this treatment, depending on the circumstances of surgery. For instance, patients who had a significant flexion contracture (were unable to straighten their knee fully) before surgery may not be prescribed this machine initially after surgery; instead the limb may be placed in a specialized sling that assists in stretching the back of the knee. You will begin working with the physical therapists (gait training, stretching, and isometric strengthening) on either the same day of surgery or the following day.

26. Will I need to take iron supplements?

    Iron supplements may be prescribed to help build up your blood count. If they are prescribed, you should begin taking the supplements prior to surgery and continue them for four weeks after surgery. In some cases (particularly bilateral surgery) the supplements may be continued for a longer period of time. They can be discontinued earlier if they cause undo constipation or other side effects. If you are having a unicompartmental, bicompartmental or patellofemoral knee replacement you typically don't need to take iron supplements.

27. Will I need a transfusion?

    The minimally invasive surgical techniques used by Dr. Lonner, as well as specialized methods of blood conservation, reduce significantly the need for blood transfusions after a single knee replacement. Typically patients undergoing replacement of one knee will not be asked to donate a unit of their own blood for later transfusion. On the other hand, patients who undergo bilateral total knee replacement surgery (both knees), may require transfusions of at least one or two units of blood. Therefore, Dr. Lonner typically has patients undergoing bilateral total knee replacement surgery (but not partial knee replacement surgery) donate one or two units of their own blood prior to surgery, just in case they need a transfusion. The alternative is to get a transfusion (if necessary) using blood from the blood bank. Additionally, at Pennsylvania Hospital, where your surgery will take place, we have a state of the art Center for Bloodless Surgery which addresses a variety of strategies for patients who do not want to accept blood transfusions for philosophical, religious, or other reasons. Patients undergoing unicompartmental, patellofemoral, or bicompartmental resurfacing typically do no need to donate blood prior to surgery.

28. How long will I need to be hospitalized?

    Most patients can be discharged within one to three days after surgery but occasionally an additional stay in inpatient rehabilitation may be necessary, particularly when both knees are replaced. On some occasions, patients who receive a robotically-assisted unicompartmental replacement may be able to go home on the day of surgery.

29. Will I be discharged to home or to an inpatient rehabilitation facility?

    Many patients who undergo unilateral total knee replacement surgery (one side) are able to go home between one and three days after surgery, but this varies from patient to patient. Some prefer an additional period in a subacute rehabilitation facility for additional therapy and care, particularly if they have limited help at home. Patients who undergo unicompartmental replacement and patellofemoral replacement generally go home one to two days after surgery and do not need inpatient rehabilitation. Patients who undergo bilateral total knee replacement surgery (both sides) may require a short stay of up to an additional week in an acute rehabilitation facility for additional training before being discharged to home.


30. What happens once I'm discharged home?

    Arrangements will be made for a physical therapist to perform physical therapy at your home two or three days a week for 4 weeks. You will be trained to walk independently and to climb stairs. Additionally, exercises will be given to you to improve your flexibility and range of motion of your knee and to perform isometric exercises to strengthen your quadriceps. Friends or family should be at home with you during the initial phase of recovery to help prepare meals and assist you with activities of daily living and routine chores. We will arrange for a visiting nurse to come to your home 14 days after surgery to remove your staples. If you come from out of state or abroad, this may need to be done by your local physician.

31. Can I use weights on my legs after surgery?

    Dr. Lonner generally does not recommend use of weights after surgery because excessive weight lifting may damage the implants or cause premature wear or loosening. However, once you've achieved full extension (that is, your knee is completely straight) you can use light ankle weights in an isometric fashion (straight leg raises). Please discuss these exercises with your physical therapist or us.

32. Will I feel depressed after surgery?

    Many patients that Dr. Lonner treats were extremely independent before the development of arthritis and before surgery. Patients who undergo knee replacement surgery may be dependent on others for assistance for several months after surgery. This may contribute to the occasional depression that we see after knee replacement surgery. Generally, this depression is short-lived and improves as patients wean off medication and get back to independent living. However, if a patient's sense of despair or depression persists, we would recommend that they speak to a specialist. If this happens to you we can give you guidance.

33. After surgery will I need to sleep on my back?

    During the initial few weeks after surgery, Dr. Lonner likes his patients to sleep on their backs, to reduce the risk of developing a flexion contracture (a bent knee). If you sleep on your side, there is a tendency to curl up in a fetal position and this can hinder the recovery of full extension (keeping it straight). Once adequate motion has been reasonably achieved and maintained, you can lay on your side or your stomach.

34. Can I put moisturizer on my knee?

    It is not unusual for the skin around the knee to become dry and flaky during the initial few weeks after knee replacement surgery. Once the surgical incision is completely healed, you can certainly put moisturizer on the knee -- any moisturizer is fine. Some patients like to put Vitamin E lotion on their incision, hoping that it will improve the appearance of the scar. However, no studies have definitively shown improvement in the scar appearance with the use of Vitamin E lotion.

35. How much pain will I have while I'm recovering from knee replacement surgery?

    This will vary from patient to patient, since everyone has a different pain tolerance. Some patients have relatively little pain, but others have a good deal of pain after knee replacement surgery. Most patients have a considerable reduction in their pain by two weeks after surgery. Once you have completely recovered from surgery, your knee may occasionally ache. We are generally successful in bringing the post-surgery pain down to a level of 1 or 2 on a pain scale of 10, but pain may be greater if you over-do it or strain the knee. It has been our experience that after surgery, the nighttime pain which patients often have and the pain associated with descending stairs take the longest to resolve (usually in the order of several months). The discomfort associated with these activities should improve over time as the inflammation of the knee is reduced and the healing process is finished. Remember, you have an artificial knee. Some discomfort may persist as part of the healing process for a year or more after surgery.


36. How long will I need narcotic pain medicines after my knee replacement?

    Some patients can discontinue narcotic medications within a week after surgery whereas others may require some sort of pain medicine for three to six months (or longer) after knee replacement surgery. This depends on a variety of factors, including the extent of surgery, type of procedure, your pain tolerance, and your progress.

37. Once I've recovered from surgery, how much pain relief will I experience?

    Total and partial knee replacement surgeries reduce pain and improve function in well over 90% of patients. Complete elimination of pain may not be achievable in all patients. Knee replacement specialists, including Dr. Lonner, often advise patients that occasionally some discomfort will persist, particularly with over-activity. Even patients who consider their outcomes "perfect" may have some mild discomfort with certain activities, relieved quickly with rest, ice, or over-the-counter medication. Dr. Lonner counsels his patients that typically they should expect their knee pain to be reduced to a level of 1 or 2 on a 10-point pain scale.

Is it Normal?

38. My knee clicks. Is this normal?

    The knee replacement does not work like a hinge. There are separate unlinked components of the implant that are held together by tendons and ligaments. During surgery, a normal amount of laxity is left in your knee; therefore, as the hard metal and plastic bearing surfaces move against each other, they will click. This is a routine occurrence. However, after several years, if your previously well-performing knee replacement begins to click more frequently than it had previously or if the click becomes painful, there may be a problem, such as loosening or wear. In those situations, please call us to discuss your symptoms.

39. The outer part of my knee is numb. Is this normal?

    All patients who have a vertical or slightly diagonal incision up the knee will have numbness lateral to the incision (on the outer side of the incision). This is because there are some small nerves that provide sensation to the outer part of the knee that need to be cut to gain exposure to the knee joint during knee replacement surgery. Over several years, the area of numbness may shrink a little, but it will always be there.

40. My knee is always a little bit swollen. Is this normal?

    Swelling is normal for the initial few months after surgery but typically improves over time. A small amount of swelling may persist forever after knee replacement surgery. Once you've recovered from surgery, if you develop a sudden increase in swelling, please call our office, as this may signify a problem with your knee replacement.

41. My knee is always a bit warm. Is this normal?

    After knee replacement surgery, the tissues around the knee become inflamed as part of the healing process. This will cause the knee to feel warm for six to twelve months after surgery. Even in the best functioning knees, there may be some chronic warmth which is not necessarily problematic. However, if your knee becomes considerably warmer than it ever had been, particularly in the presence of increased swelling or pain, you should notify us immediately because there may be a problem such as an infection or loosening.

42. Why is the hair growth on my knee different than it was before?

    After knee replacement surgery is performed there is an increase in local blood flow to the knee as part of the healing process. This can cause an increase in hair growth on the knee.

43. My knee is stiff. Is that normal?

    It is very common for knees to feel stiff for up to a year after knee replacement surgery, particularly after prolonged sitting or inactivity, even if your knee motion is satisfactory by objective measures. Usually the knee "loosens up" once you resume walking or exercise.

44. Will my knee replacement set off a metal detector?

    Most metal detectors at airports and other facilities will detect knee replacements. We will provide you with a card that states you have metallic implants in your knee(s); however, security personnel will typically have you step aside so they can scan your knee(s). To make your travels a little less difficult and stressful, we advise you to wear loose fitting pants or skirts and give yourself plenty of travel time.