Wednesday, May 23, 2012

Frozen Shoulder

I see many patients daily with a certain degree of stiffness of the joint contributing to their shoulder pain.  Sometimes the loss of motion is obvious and dramatic and sometimes it is very subtle and only noted when we compare the other shoulder.  Below is some educational information from the AAOS that I found very helpful for patients.

Frozen shoulder, also called adhesive capsulitis, causes pain and stiffness in the shoulder. Over time, the shoulder becomes very hard to move.
Frozen shoulder occurs in about 2% of the general population. It most commonly affects people between the ages of 40 and 60, and occurs in women more often than men.
Your shoulder is a ball-and-socket joint made up of three bones: your upper arm bone (humerus), your shoulder blade (scapula), and your collarbone (clavicle).
The head of the upper arm bone fits into a shallow socket in your shoulder blade. Strong connective tissue, called the shoulder capsule, surrounds the joint.
To help your shoulder move more easily, synovial fluid lubricates the shoulder capsule and the joint.
The shoulder capsule surrounds the shoulder joint and rotator cuff tendons.
Reproduced and modified from The Body Almanac. (c) American Academy of Orthopaedic Surgeons, 2003.
In frozen shoulder, the shoulder capsule thickens and becomes tight. Stiff bands of tissue — called adhesions — develop. In many cases, there is less synovial fluid in the joint.
The hallmark sign of this condition is being unable to move your shoulder - either on your own or with the help of someone else. It develops in three stages:


In the"freezing" stage, you slowly have more and more pain. As the pain worsens, your shoulder loses range of motion. Freezing typically lasts from 6 weeks to 9 months.


Painful symptoms may actually improve during this stage, but the stiffness remains. During the 4 to 6 months of the "frozen" stage, daily activities may be very difficult.


Shoulder motion slowly improves during the "thawing" stage. Complete return to normal or close to normal strength and motion typically takes from 6 months to 2 years.
In frozen shoulder, the smooth tissues of the shoulder capsule become thick, stiff, and inflamed.
The causes of frozen shoulder are not fully understood. There is no clear connection to arm dominance or occupation. A few factors may put you more at risk for developing frozen shoulder.
Diabetes. Frozen shoulder occurs much more often in people with diabetes, affecting 10% to 20% of these individuals. The reason for this is not known.
Other diseases. Some additional medical problems associated with frozen shoulder include hypothyroidism, hyperthyroidism, Parkinson's disease, and cardiac disease.
Immobilization. Frozen shoulder can develop after a shoulder has been immobilized for a period of time due to surgery, a fracture, or other injury. Having patients move their shoulders soon after injury or surgery is one measure prescribed to prevent frozen shoulder.
Pain from frozen shoulder is usually dull or aching. It is typically worse early in the course of the disease and when you move your arm. The pain is usually located over the outer shoulder area and sometimes the upper arm.
Doctor Examination

Physical Examination

Your doctor will test the range of motion in your shoulder.
Reproduced with permission from JF Sarwark, ed: Essentials of Musculoskeletal Care, ed 4. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2010.
After discussing your symptoms and medical history, your doctor will examine your shoulder. Your doctor will move your shoulder carefully in all directions to see if movement is limited and if pain occurs with the motion. The range of motion when someone else moves your shoulder is called "passive range of motion." Your doctor will compare this to the range of motion you display when you move your shoulder on your own ("active range of motion"). People with frozen shoulder have limited range of motion both actively and passively.

Imaging Tests

Other tests that may help your doctor rule out other causes of stiffness and pain include:
X-rays. Dense structures, such as bone, show up clearly on x-rays. X-rays may show other problems in your shoulder, such as arthritis.
Magnetic resonance imaging (MRI) and ultrasound. These studies can create better images of problems with soft tissues, such as a torn rotator cuff.
Frozen shoulder generally gets better over time, although it may take up to 3 years.
The focus of treatment is to control pain and restore motion and strength through physical therapy.

Nonsurgical Treatment

More than 90% of patients improve with relatively simple treatments to control pain and restore motion.
Non-steroidal anti-inflammatory medicines. Drugs like aspirin and ibuprofen reduce pain and swelling.
Steroid injections. Cortisone is a powerful anti-inflammatory medicine that is injected directly into your shoulder joint.
Physical therapy. Specific exercises will help restore motion. These may be under the supervision of a physical therapist or via a home program. Therapy includes stretching or range of motion exercises for the shoulder. Sometimes heat is used to help loosen the shoulder up before the stretching exercises.. Below are examples of some of the exercises that might be recommended.
  • External rotation — passive stretch. Stand in a doorway and bend your affected arm 90 degrees to reach the doorjamb. Keep your hand in place and rotate your body as shown in the illustration. Hold for 30 seconds. Relax and repeat.
  • External Rotation - Passive Stretch
    Reproduced with permission from JF Sarwark, ed: Essentials of Musculoskeletal Care, ed 4. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2010.
  • Forward flexion — supine position. Lie on your back with your legs straight. Use your unaffected arm to lift your affected arm overhead until you feel a gentle stretch. Hold for 15 seconds and slowly lower to start position. Relax and repeat.
  • Forward Flexion - Supine Position
    Reproduced with permission from JF Sarwark, ed: Essentials of Musculoskeletal Care, ed 4. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2010.
  • Crossover arm stretch. Gently pull one arm across your chest just below your chin as far as possible without causing pain. Hold for 30 seconds. Relax and repeat.
  • Crossover Arm Stretch
    Reproduced with permission from JF Sarwark, ed: Essentials of Musculoskeletal Care, ed 4. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2010.

Surgical Treatment

If your symptoms are not relieved by therapy and anti-inflammatory medicines, you and your doctor may discuss surgery. It is important to talk with your doctor about your potential for recovery continuing with simple treatments, and the risks involved with surgery.
The goal of surgery for frozen shoulder is to stretch and release the stiffened joint capsule. The most common methods include manipulation under anesthesia and shoulder arthroscopy.
Manipulation under anesthesia. During this procedure, you are put to sleep. Your doctor will force your shoulder to move which causes the capsule and scar tissue to stretch or tear. This releases the tightening and increases range of motion.
Shoulder arthroscopy. In this procedure, your doctor will cut through tight portions of the joint capsule. This is done using pencil-sized instruments inserted through small incisions around your shoulder.
In many cases, manipulation and arthroscopy are used in combination to obtain maximum results. Most patients have very good outcomes with these procedures.
These photos taken through an arthroscope show a normal shoulder joint lining (left) and an inflamed joint lining damaged by frozen shoulder.
Recovery. After surgery, physical therapy is necessary to maintain the motion that was achieved with surgery. Recovery times vary, from 6 weeks to three months. Although it is a slow process, your commitment to therapy is the most important factor in returning to all the activities you enjoy.
Long-term outcomes after surgery are generally good, with most patients having reduced or no pain and greatly improved range of motion. In some cases, however, even after several years, the motion does not return completely and a small amount of stiffness remains.
Although uncommon, frozen shoulder can recur, especially if a contributing factor like diabetes is still present.

From the AAOS



Osteonecrosis of the Knee

A relatively common cause of knee pain in older women occurs when a segment of bone loses its blood supply and begins to die. This condition is called osteonecrosis, which literally means "bone death." More than 3 times as many women as men are affected; most are over the age of 60 years.

In the knee, the knobby portion of the thighbone on the inside of the knee (the medial femoral condyle) is most often affected. However, osteonecrosis of the knee may also occur on the outside of the knee (the lateral femoral condyle) or on the flat top of the lower leg bone (tibial plateau).

The exact cause of the osteonecrosis of the knee is not yet known. One theory is that a stress fracture, combined with a specific activity or trauma, results in an altered blood supply to the bone. Another theory supposes that a build-up of fluid within the bone puts pressure on blood vessels and diminishes circulation.
Osteonecrosis of the knee is also associated with certain conditions and treatments, such as obesity, sickle cell anemia, lupus, kidney transplants, and steroid therapy. Steroid-induced osteonecrosis frequently affects multiple joints and is usually seen in young patients.
Regardless of the cause, if the disease is not identified and treated early, it can develop into severe osteoarthritis.

  • Sudden pain on the inside of the knee, perhaps triggered by a specific activity or minor injury
  • Increased pain at night and with activity
  • Swelling over the front and inside of the knee
  • Heightened sensitivity to touch in the area
  • Limited motion due to pain

Osteonecrosis of the knee develops through four stages, which can be identified by symptoms and X-rays.
Stage I: Symptoms are most intense in the earliest stage. Symptoms may continue for 6 to 8 weeks and then subside. Because X-rays are normal, a positive bone scan is needed to make the diagnosis. Treatment at this point is not surgical. The focus is on pain relief and protected weightbearing.
Stage II: It may take several months for the disease to progress to Stage II. At this point, X-rays will show that the rounded edge of the thighbone is starting to flatten out. An MRI or bone scan can be used to diagnose the disease. A computed tomography (CT) scan may also be used to measure the affected area.
Stage III: By the time the disease reaches stage III (3 to 6 months after onset), it is clearly visible on X-rays and no other diagnostic tests are needed. The articular cartilage covering the bone begins to loosen as the bone itself begins to die. Surgical treatments may be considered at this point.
Stage IV: At this point, the bone begins to collapse. The articular cartilage is destroyed, the joint space narrows, and bone spurs may form. Severe osteoarthritis results and joint replacement surgery may be necessary.

Nonsurgical Treatment

In the early stages of the disease, treatment is not surgical. If the affected area is small, this treatment may be all that is needed.
Options include:
  • Medications to reduce the pain
  • A brace to relieve pressure on the joint surface
  • A conditioning program with exercises to strengthen your thigh muscles
  • Activity modifications to reduce knee pain

Surgical Treatment

If more than half of the bone surface is affected, you may need surgical treatment. Several different procedures may be used to treat osteonecrosis of the knee.
Among the surgical options are:
  • Arthroscopic cleansing (debridement) of the joint
  • Drilling to reduce pressure on the bone surface
  • Procedures to shift weightbearing away from the affected area
  • Unicompartmental or total knee replacement



Monday, January 23, 2012

Post Arthroscopy Osteonecrosis of the Knee

Osteonecrosis is the death of bone tissue. There are three types of knee osteonecrosis: 1) spontaneous (occurs without a known cause), 2) post-arthroscopy (occurs after an arthroscopic procedure), and 3) secondary to some other condition such as lupus, use of steroids, or alcohol abuse.
Spontaneous osteonecrosis of the knee is also referred to as SPONK. It usually occurs in one compartment or section of the knee, while secondary osteonecrosis (caused by disease or medical therapy) affects more than one compartment. The bottom, round part of the femur(thighbone) called the femoral condyle is affected most of the time.
Spontaneous osteonecrosis usually occurs in patients older than 55 years, while secondary osteonecrosis can occur at any age. Women are affected by SPONK three times more often than men. The reason for this is unknown.
Osteonecrosis of the knee is uncommon after arthroscopy. It usually occurs when some form of heat such as laser or other thermal devices were used during the procedure. The patient starts to develop worse pain after arthroscopy than before. Knee swelling is a common feature of this problem.  (Dr. M comment: This is one reason that I never use these laser or thermal devices for knee arthroscopy.  The other reason is that they are not necessary.)
MRIs are relied upon to identify and diagnose osteonecrosis of the knee. In more advanced cases, a plain x-ray may reveal the problem.  Bone scans are only reliable 56 per cent of the time. Osteonecrosis shows up on MRIs 100 per cent of the time. The main disadvantage of MRIs is the delay in findings after symptoms have started. Early on in the disease process, nothing unusual shows up on MRIs. The exact best timing for identifying this condition using MRIs remains unknown.
Once the condition has been diagnosed, then treatment begins. Everything is done to preserve the joint and prevent further breakdown of the bone. Early lesions can be treated conservatively (without surgery). The types of lesions that respond to nonoperative care have no low-density lines deep in the femoral condyles (as viewed on MRI scans) and no defects in the shape of the femoral condyles.
Patients are directed to avoid putting weight on the knee along with activity limitations. They must be patient as this protective process can take from three to eighteen months. Bone resorption may be stopped by the use of medications called bisphosphonates. Knee pain can be managed with analgesics (pain relievers). Treatment with bisphosphonates is fairly new and has not been proven effective for all patients yet. Further study of these drugs must be completed to guide the surgeon in knowing when and how to use bisphosphonates, as well as which patients would benefit the most.
Another newer drug treatment for knee osteonecrosis is tumor necrosis factor alpha (TNFA). This substance is injected right into the knee joint. Case reports show rapid (one-week later) improvement in pain and stiffness. Signs of healing are seen on MRIs after only one month.
But when the case is too far advanced or when nonoperative care doesn't work, then surgery to repair the lesion may be needed. The type of surgery done depends on where the damage is located and how severe it is. The surgeon can drill holes in the bone, a procedure called core decompressionDebridement (scraping the damaged area) followed by bone grafting to replace the missing bone has also been tried.
There haven't been very many cases treated with these various techniques. So, which one works best and for what types of knee osteonecrosis are also unknown factors. The most information we have is on the outcomes using unicompartmental knee arthroplasty. In this procedure, the surgeon replaces just the half of the joint that's been affected by the necrosis (rather than doing a full knee joint replacement).  Some patients may require a total knee replacement if there is evidence of arthritis elsewhere in the knee or if the knee joint is malaligned due to arthritis or osteonecrosis.
Results reported from a limited number of studies report excellent results with this technique. Researchers consider the unilateral knee arthroplasty a very promising approach, but once again, more studies are needed to confirm these results and to see what happens in the long-run.
Right now, we only have limited information and understanding of what causes knee osteonecrosis and how to treat it. At the present time, research efforts are directed toward finding ways to preserve the joint, rather than replace it. Nonoperative treatments with new methods of tissue engineering may eventually provide a breakthrough in the treatment of this disease.

Bisphosphonate treatment for knee osteonecrosis offered rapid pain relief and radiological consolidation of the osteonecrotic area, according to Swiss researchers.
In a prospective, researchers studied how bisphosphonate treatment affected 28 patients with spontaneous or arthroscopy-induced knee osteonecrosis. Patients had osteonecrotic lesions and bone marrow edema. Twenty-two patients developed osteonecrosis after knee arthroscopy, and six patients developed spontaneous osteonecrosis.
First, patients received 120 mg of intravenous pamidronate in three to four perfusions over a 2-week period, followed by 70 mg/day of the oral bisphosphonate alendronate for 4 to 6 months.
The results showed that bisphosphonate treatment was beneficial to patients. Bisphosphonate treatment quickly relieved pain, with Visual Analog Scores (VAS) dropping from 8.2 ± 1.2 at baseline to 5.02 ± 0.6 at 4 to 6 weeks postoperative (< .001). The VAS decreased by 80% at 6 months (<. 001). Fifteen of 28 patients had complete symptom resolution at 6 months follow-up; 6 patients had minimal symptoms (VAS 1 or 2).Magnetic resonance imaging revealed that in 18 of 28 patients, bone marrow edema completely resolved. The edema was significantly reduced in the remaining patients. In some cases, the researchers observed complete resolution of the osteonecrotic area; in others, they saw demarcation with sclerotic changes.
Two patients had an unsatisfactory treatment effect; they both underwent arthroplasty.
The observations of the study are certainly consistent with the antiresorptive mechanism of bisphosphonates. In disorders of which the pathophysiology is dependent on turnover of bone or substantial osseous resorption, bisphosphonates present a potential therapeutic strategy.
However, without a true control group (as the authors note), this study does not rigorously show that the medication altered the natural history of the ON.

I perform many knee arthroscopies (~150-200+) every year and have done so for 20 years. If we see a problem post-operatively, the most common problem we may see in patients with knee osteoarthritis, is a continuation or increase in their knee pain from the arthritis. The pain from their meniscus tear may be improved, but how the arthritis will respond to an arthroscopic surgery can be unpredictable.  
Post knee arthroscopy osteonecrosis is more uncommon but below are some examples of my own patients over many years who have had this problem.  They have, in turn, gone on to require a knee replacement with good results.  

Here is a standing x-ray of a patient pre-op.  You can see that in his right knee there is some mild narrowing of the  joint on the inside (medial side) of the knee.  This is a result of early arthritis.  His meniscus tear was causing pain, and an arthroscopy was performed to relieve that pain.  He did well for many months after the surgery and came back with an increase in pain .

Here is that patient's x-ray many months later showing loss of the medial joint space and collapse of the femoral condyle due to osteonecrosis.  He is bone on bone with collapse of the medial joint.

These are the x-rays of a second patient, who seemed to have no signs of any arthritis on the pre-op films before his knee arthroscopy.  After the surgery, the pain from his meniscus tear was relieved for well over a year.

Just over a year, from his knee arthroscopy, he returned in pain and a follow up x-ray was performed.  It clearly shows collapse of the medial femoral condyle due to osteonecrosis.  This patient, like the one above, went onto a knee replacement, with an excellent result.  

So what's the point.  

Under the best of circumstances, even with an experienced surgeon, a simple knee arthroscopy for a meniscus tear can have develop problems.  While the risk of surgery, like a knee scope, is relatively low, the risk is never "zero".  

We do not really know what causes post arthroscopy osteonecrosis in these knees.  

The references for the science are below.  The patients are mine.



Maria S. Goddard, and Harpal S. Khanuja, MD. Special Focus. Knee Reconstruction. Osteonecrosis of the Knee. In Current Orthopaedic Practice. January/February 2009. Vol. 20. No. 1. Pp. 65-72.a
Bisphosphonates may offer benefit for knee osteonecrosis
Kraenzlin ME, Graf C, Meier C, et al. Knee Surg Sports Traumatol Arthrosoc. DOI 10.1007/s00167-008-0673-0

Thursday, January 19, 2012

Knee Replacement Surgery

If your knee is severely damaged by arthritis or injury, it may be hard for you to perform simple activities, such as walking or climbing stairs. You may even begin to feel pain while you are sitting or lying down.
If nonsurgical treatments like medications and using walking supports are no longer helpful, you may want to consider total knee replacement surgery. Joint replacement surgery is a safe and effective procedure to relieve pain, correct leg deformity, and help you resume normal activities.
Knee replacement surgery was first performed in 1968. Since then, improvements in surgical materials and techniques have greatly increased its effectiveness. Total knee replacements are one of the most successful procedures in all of medicine. According to the Agency for Healthcare Research and Quality, more than 600,000 knee replacements are performed each year in the United States.
Whether you have just begun exploring treatment options or have already decided to have total knee replacement surgery, this article will help you understand more about this valuable procedure.
Normal knee anatomy.
The knee is the largest joint in the body and having healthy knees is required to perform most everyday activities.
The knee is made up of the lower end of the thighbone (femur), the upper end of the shinbone (tibia), and the kneecap (patella). The ends of these three bones where they touch are covered with articular cartilage, a smooth substance that protects the bones and enables them to move easily.
The menisci are located between the femur and tibia. These C-shaped wedges act as "shock absorbers" that cushion the joint.
Large ligaments hold the femur and tibia together and provide stability. The long thigh muscles give the knee strength.
All remaining surfaces of the knee are covered by a thin lining called the synovial membrane. This membrane releases a fluid that lubricates the cartilage, reducing friction to nearly zero in a healthy knee.
Normally, all of these components work in harmony. But disease or injury can disrupt this harmony, resulting in pain, muscle weakness, and reduced function.
The most common cause of chronic knee pain and disability is arthritis. Although there are many types of arthritis, most knee pain is caused by just three types: osteoarthritis, rheumatoid arthritis, and post-traumatic arthritis.
  • Osteoarthritis. This is an age-related "wear and tear" type of arthritis. It usually occurs in people 50 years of age and older, but may occur in younger people, too. The cartilage that cushions the bones of the knee softens and wears away. The bones then rub against one another, causing knee pain and stiffness.
  • Rheumatoid arthritis. This is a disease in which the synovial membrane that surrounds the joint becomes inflamed and thickened. This chronic inflammation can damage the cartilage and eventually cause cartilage loss, pain, and stiffness. Rheumatoid arthritis is the most common form of a group of disorders termed "inflammatory arthritis."
  • Post-traumatic arthritis. This can follow a serious knee injury. Fractures of the bones surrounding the knee or tears of the knee ligaments may damage the articular cartilage over time, causing knee pain and limiting knee function.
Osteoarthritis often results in bone rubbing on bone. Bone spurs are a common feature of this form of arthritis.
A knee replacement (also called knee arthroplasty) might be more accurately termed a knee "resurfacing" because only the surface of the bones are actually replaced.
There are four basic steps to a knee replacement procedure.
  • Prepare the bone. The damaged cartilage surfaces at the ends of the femur and tibia are removed along with a small amount of underlying bone.
  • Position the metal implants. The removed cartilage and bone is replaced with metal components that recreate the surface of the joint. These metal parts may be cemented or "press-fit" into the bone.
  • Resurface the patella. The undersurface of the patella (kneecap) is cut and resurfaced with a plastic button. Some surgeons do not resurface the patella, depending upon the case.
  • Insert a spacer. A medical-grade plastic spacer is inserted between the metal components to create a smooth gliding surface.
(Left) Severe osteoarthritis. (Right) The arthritic cartilage and underlying bone has been removed and resurfaced with metal implants on the femur and tibia. A plastic spacer has been placed in between the implants. The patellar component is not shown for clarity.
Is Total Knee Replacement for You?
The decision to have total knee replacement surgery should be a cooperative one between you, your family, your family physician, and your orthopaedic surgeon. Your physician may refer you to an orthopaedic surgeon for a thorough evaluation to determine if you might benefit from this surgery.

When Surgery Is Recommended

There are several reasons why your doctor may recommend knee replacement surgery. People who benefit from total knee replacement often have:
A knee that has become bowed as a result of severe arthritis.
  • Severe knee pain or stiffness that limits your everyday activities, including walking, climbing stairs, and getting in and out of chairs. You may find it hard to walk more than a few blocks without significant pain and you may need to use a cane or walker
  • Moderate or severe knee pain while resting, either day or night
  • Chronic knee inflammation and swelling that does not improve with rest or medications
  • Knee deformity — a bowing in or out of your knee
  • Failure to substantially improve with other treatments such as anti-inflammatory medications, cortisone injections, lubricating injections, physical therapy, or other surgeries

Candidates for Surgery

There are no absolute age or weight restrictions for total knee replacement surgery.
Recommendations for surgery are based on a patient's pain and disability, not age. Most patients who undergo total knee replacement are age 50 to 80, but orthopaedic surgeons evaluate patients individually. Total knee replacements have been performed successfully at all ages, from the young teenager with juvenile arthritis to the elderly patient with degenerative arthritis.
Orthopaedic Evaluation
An evaluation with an orthopaedic surgeon consists of several components:
  • A medical history. Your orthopaedic surgeon will gather information about your general health and ask you about the extent of your knee pain and your ability to function.
  • A physical examination. This will assess knee motion, stability, strength, and overall leg alignment.
  • X-rays. These images help to determine the extent of damage and deformity in your knee.
  • Other tests. Occasionally blood tests, or advanced imaging such as a magnetic resonance imaging (MRI) scan, may be needed to determine the condition of the bone and soft tissues of your knee.
(Left) In this x-ray of a normal knee, the space between the bones indicates healthy cartilage (arrow). (Right) This x-ray of an arthritic knee shows severe loss of joint space and bone spurs (arrows).
Your orthopaedic surgeon will review the results of your evaluation with you and discuss whether total knee replacement is the best method to relieve your pain and improve your function. Other treatment options — including medications, injections, physical therapy, or other types of surgery — will also be considered and discussed.
In addition, your orthopaedic surgeon will explain the potential risks and complications of total knee replacement, including those related to the surgery itself and those that can occur over time after your surgery.
Deciding to Have Knee Replacement Surgery

Realistic Expectations

An important factor in deciding whether to have total knee replacement surgery is understanding what the procedure can and cannot do.
More than 90% of people who have total knee replacement surgery experience a dramatic reduction of knee pain and a significant improvement in the ability to perform common activities of daily living. But total knee replacement will not allow you to do more than you could before you developed arthritis.
With normal use and activity, every knee replacement implant begins to wear in its plastic spacer. Excessive activity or weight may speed up this normal wear and may cause the knee replacement to loosen and become painful. Therefore, most surgeons advise against high-impact activities such as running, jogging, jumping, or other high-impact sports for the rest of your life after surgery.
Realistic activities following total knee replacement include unlimited walking, swimming, golf, driving, light hiking, biking, ballroom dancing, and other low-impact sports.
With appropriate activity modification, knee replacements can last for many years.

Possible Complications of Surgery

The complication rate following total knee replacement is low. Serious complications, such as a knee joint infection, occur in fewer than 2% of patients. Major medical complications such as heart attack or stroke occur even less frequently. Chronic illnesses may increase the potential for complications. Although uncommon, when these complications occur, they can prolong or limit full recovery.
Discuss your concerns thoroughly with your orthopaedic surgeon prior to surgery.
Blood clots may develop in leg veins.
Infection. Infection may occur in the wound or deep around the prosthesis. It may happen while in the hospital or after you go home. It may even occur years later. Minor infections in the wound area are generally treated with antibiotics. Major or deep infections may require more surgery and removal of the prosthesis. Any infection in your body can spread to your joint replacement.
Blood clots. Blood clots in the leg veins are the most common complication of knee replacement surgery. These clots can be life-threatening if they break free and travel to your lungs. Your orthopaedic surgeon will outline a prevention program, which may include periodic elevation of your legs, lower leg exercises to increase circulation, support stockings, and medication to thin your blood.
Implant problems. Although implant designs and materials, as well as surgical techniques, continue to advance, implant surfaces may wear down and the components may loosen. Additionally, although an average of 115° of motion is generally anticipated after surgery, scarring of the knee can occasionally occur, and motion may be more limited, particularly in patients with limited motion before surgery.
Continued pain. A small number of patients continue to have pain after a knee replacement. This complication is rare, however, and the vast majority of patients experience excellent pain relief following knee replacement.
Neurovascular injury. While rare, injury to the nerves or blood vessels around the knee can occur during surgery.
Preparing for Surgery

Medical Evaluation

If you decide to have total knee replacement surgery, your orthopaedic surgeon may ask you to schedule a complete physical examination with your family physician several weeks before the operation. This is needed to make sure you are healthy enough to have the surgery and complete the recovery process. Many patients with chronic medical conditions, like heart disease, may also be evaluated by a specialist, such as a cardiologist, before the surgery.


Several tests, such as blood and urine samples, and an electrocardiogram, may be needed to help your orthopaedic surgeon plan your surgery.


Tell your orthopaedic surgeon about the medications you are taking. He or she will tell you which medications you should stop taking and which you should continue to take before surgery.

Dental Evaluation

Although the incidence of infection after knee replacement is very low, an infection can occur if bacteria enter your bloodstream. To reduce the risk of infection, major dental procedures (such as tooth extractions and periodontal work) should be completed before your total knee replacement surgery.

Urinary Evaluations

People with a history of recent or frequent urinary infections should have a urological evaluation before surgery. Older men with prostate disease should consider completing required treatment before undertaking knee replacement surgery.

Social Planning

Although you will be able to walk on crutches or a walker soon after surgery, you will need help for several weeks with such tasks as cooking, shopping, bathing, and doing laundry.
If you live alone, your orthopaedic surgeon's office, a social worker, or a discharge planner at the hospital can help you make advance arrangements to have someone assist you at home. They also can help you arrange for a short stay in an extended care facility during your recovery, if this option works best for you.

Home Planning

Several modifications can make your home easier to navigate during your recovery. The following items may help with daily activities:
  • Safety bars or a secure handrail in your shower or bath
  • Secure handrails along your stairways
  • A stable chair for your early recovery with a firm seat cushion (and a height of 18 to 20 inches), a firm back, two arms, and a footstool for intermittent leg elevation
  • A toilet seat riser with arms, if you have a low toilet
  • A stable shower bench or chair for bathing
  • Removing all loose carpets and cords
  • A temporary living space on the same floor because walking up or down stairs will be more difficult during your early recovery
Your Surgery
You will most likely be admitted to the hospital on the day of your surgery.


After admission, you will be evaluated by a member of the anesthesia team. The most common types of anesthesia are general anesthesia (you are put to sleep) or spinal, epidural, or regional nerve block anesthesia (you are awake but your body is numb from the waist down). The anesthesia team, with your input, will determine which type of anesthesia will be best for you.


The procedure itself takes approximately 1 to 2 hours. Your orthopaedic surgeon will remove the damaged cartilage and bone, and then position the new metal and plastic implants to restore the alignment and function of your knee.
Different types of knee implants are used to meet each patient's individual needs.
(Left) An x-ray of a severely arthritic knee. (Right) The x-ray appearance of a total knee replacement. Note that the plastic spacer between the bones does not show up in an x-ray.
After surgery, you will be moved to the recovery room, where you will remain for several hours while your recovery from anesthesia is monitored. After you wake up, you will be taken to your hospital room.
Your Hospital Stay
You will most likely stay in the hospital for several days.

Pain Management

After surgery, you will feel some pain, but your surgeon and nurses will provide medication to make you feel as comfortable as possible. Pain management is an important part of your recovery. Walking and knee movement will begin soon after surgery, and when you feel less pain, you can start moving sooner and get your strength back more quickly. Talk with your surgeon if postoperative pain becomes a problem.

Blood Clot Prevention

Your orthopaedic surgeon may prescribe one or more measures to prevent blood clots and decrease leg swelling. These may include special support hose, inflatable leg coverings (compression boots), and blood thinners.
Foot and ankle movement also is encouraged immediately following surgery to increase blood flow in your leg muscles to help prevent leg swelling and blood clots.

Physical Therapy

To restore movement in your knee and leg, your surgeon may use a knee support that slowly moves your knee while you are in bed. The device, called a continuous passive motion (CPM) exercise machine, decreases leg swelling by elevating your leg and improves your blood circulation by moving the muscles of your leg.  In many cases, I have found to be unnecessary and studies demonstrate that the initial use of a CPM will not affect long term motion of the knee. 
Most patients begin exercising their knee the day after surgery. A physical therapist will teach you specific exercises to strengthen your leg and restore knee movement to allow walking and other normal daily activities soon after your surgery.

Preventing Pneumonia

It is common for patients to have shallow breathing in the early postoperative period. This is usually due to the effects of anesthesia, pain medications, and increased time spent in bed. This shallow breathing can lead to a partial collapse of the lungs (termed "atelectasis") which can make patients susceptible to pneumonia. To help prevent this, it is important to take frequent deep breaths. Your nurse may provide a simple breathing apparatus called a spirometer to encourage you to take deep breaths.
Your Recovery at Home
The success of your surgery will depend largely on how well you follow your orthopaedic surgeon's instructions at home during the first few weeks after surgery.

Wound Care

You will have stitches or staples running along your wound or a suture beneath your skin on the front of your knee. The stitches or staples will be removed several weeks after surgery. A suture beneath your skin will not require removal.
Avoid soaking the wound in water until it has thoroughly sealed and dried. You may continue to bandage the wound to prevent irritation from clothing or support stockings.


Some loss of appetite is common for several weeks after surgery. A balanced diet, often with an iron supplement, is important to help your wound heal and to restore muscle strength.


Exercise is a critical component of home care, particularly during the first few weeks after surgery. You should be able to resume most normal activities of daily living within 3 to 6 weeks following surgery. Some pain with activity and at night is common for several weeks after surgery.
Your activity program should include:
  • A graduated walking program to slowly increase your mobility, initially in your home and later outside
  • Resuming other normal household activities, such as sitting, standing, and climbing stairs
  • Specific exercises several times a day to restore movement and strengthen your knee. You probably will be able to perform the exercises without help, but you may have a physical therapist help you at home or in a therapy center the first few weeks after surgery.
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You will most likely be able to resume driving when your knee bends enough that you can enter and sit comfortably in your car, and when your muscle control provides adequate reaction time for braking and acceleration. Most people resume driving approximately 4 to 6 weeks after surgery.
Avoiding Problems After Surgery

Blood Clot Prevention

Follow your orthopaedic surgeon's instructions carefully to reduce the risk of blood clots developing during the first several weeks of your recovery. He or she may recommend that you continue taking the blood thinning medication you started in the hospital. Notify your doctor immediately if you develop any of the following warning signs.
Warning signs of blood clots. The warning signs of possible blood clots in your leg include:
  • Increasing pain in your calf
  • Tenderness or redness above or below your knee
  • Increasing swelling in your calf, ankle, and foot
Warning signs of pulmonary embolism. The warning signs that a blood clot has traveled to your lung include:
  • Sudden shortness of breath
  • Sudden onset of chest pain
  • Localized chest pain with coughing

Preventing Infection

A common cause of infection following total knee replacement surgery is from bacteria that enter the bloodstream during dental procedures, urinary tract infections, or skin infections. These bacteria can lodge around your knee replacement and cause an infection.
After your knee replacement, you must take preventive antibiotics before dental or surgical procedures that could allow bacteria to enter your bloodstream.
Warning signs of infection. Notify your doctor immediately if you develop any of the following signs of a possible knee replacement infection:
  • Persistent fever (higher than 100°F orally)
  • Shaking chills
  • Increasing redness, tenderness, or swelling of the knee wound
  • Drainage from the knee wound
  • Increasing knee pain with both activity and rest

Avoiding Falls

A fall during the first few weeks after surgery can damage your new knee and may result in a need for further surgery. Stairs are a particular hazard until your knee is strong and mobile. You should use a cane, crutches, a walker, hand rails, or have someone to help you until you have improved your balance, flexibility, and strength.
Your surgeon and physical therapist will help you decide what assistive aides will be required following surgery and when those aides can safely be discontinued.

How Your New Knee Is Different

Improvement of knee motion is a goal of total knee replacement, but restoration of full motion is uncommon. The motion of your knee replacement after surgery can be predicted by the range of motion you have in your knee before surgery. Most patients can expect to be able to almost fully straighten the replaced knee and to bend the knee sufficiently to climb stairs and get in and out of a car. Kneeling is sometimes uncomfortable, but it is not harmful.  It is usually advisable to avoid kneeling directly on the knee cap as this can damage the bone (creating a fracture) or the connection between the knee cap bone and the plastic joint surface.
Most people feel some numbness in the skin around your incision. You also may feel some stiffness, particularly with excessive bending activities.
Most people also feel or hear some clicking of the metal and plastic with knee bending or walking. This is a normal. These differences often diminish with time and most patients find them to be tolerable when compared with the pain and limited function they experienced prior to surgery.
It can take a year or more for you to reach maximum benefit from your knee replacement.  While the joint surface is replaced and no longer causes pain, the tendons, ligaments and other soft tissues around the knee can be sore and painful for about a year.  Most patients can return to light work at about 2-3 months depending on their pace of recovery.  Every patient is different.  
Your new knee may activate metal detectors required for security in airports and some buildings. Tell the security agent about your knee replacement if the alarm is activated.

Protecting Your Knee Replacement

After surgery, make sure you also do the following:
  • Participate in regular light exercise programs to maintain proper strength and mobility of your new knee.
  • Take special precautions to avoid falls and injuries. If you break a bone in your leg, you may require more surgery.
  • Make sure your dentist knows that you have a knee replacement. You should be given antibiotics before all dental surgery for the rest of your life.
  • See your orthopaedic surgeon periodically for a routine follow-up examination and x-rays, usually once a year for the first 2 years and then every other year after that.

Extending the Life of Your Knee Implant

Currently, more than 90% of modern total knee replacements are still functioning well 15 years after the surgery. Following your orthopaedic surgeon's instructions after surgery and taking care to protect your knee replacement and your general health are important ways you can contribute to the final success of your surgery.

Here is a link to other knee replacement information on my web site.