Knee care at Northern Arizona Orthopaedics

In the Arthritis and Fracture Care Center and the Sports Medicine Center, we specialize in these important weight-bearing joints, helping patients find comfort and mobility again after pain. Knee problems are common among young and old, and professional athletes and light recreational activity-goers. Knee pain can be caused by a condition that has developed over time or from overuse like osteoarthritis, arthritis, and runner’s knee, or from sports injury, such as a meniscus tear or dislocated kneecap.

Candidates for knee replacement surgery typically report chronic knee pain that:

  • Limits everyday activities, including walking, climbing stairs, sitting down and resting
  • Continues during daytime or nighttime rest
  • Causes knee inflammation and swelling that doesn’t improve with medication
  • Knee deformity (knee bows in or out)
  • Isn’t adequately relieved with anti-inflammatory drugs, physical therapy or walking aids
  • Other Knee Surgeries

According to the American Academy of Orthopedic Surgeons, 90 percent of people who have a knee replacement have a lot less pain. Most of these people are able to perform daily activities and stay active. In many cases, they’re able to resume activities like golf and walking that their arthritic pain made them give up years ago. Advancements in knee surgeries have resulted in significant benefits for patients. Arthroscopic techniques and partial knee joint replacement, which conserves healthy bone, are two proven minimally invasive approaches that can help patients relieve their pain and return to their activities. A total knee replacement (TKR) is also known as a total knee arthroplasty (TKA) and it relies on a mechanical implant to replace your actual knee. Our surgeries have excellent success rates, with our surgical implants lasting well over 20 years. Current advancements in implants now allow for some TKRs to last 30 years (see more information on our 30-Year Knee).

We take great pride in the positive patient outcomes and high patient satisfaction scores of those who have trusted Northern Arizona Orthopaedics to care and treat their knee pain.

Patient Education

For Knee:


All information provided on this website is for information purposes only. Please see a healthcare professional for medical advice. If you are seeking this information in an emergency situation, please call 911 and seek emergency help.

All materials copyright © 2015 Smith & Nephew, All Rights Reserved.


Is Total Knee Replacement Surgery for You?

Knee Surgery

The good news is that if you are considering total knee replacement surgery, you're not alone. According to the American Academy of Orthopaedic Surgeons, more than 600,000 such procedures are performed in the US each year.1 Even better news is that the US Department of Health and Human services considers total knee replacement to be one of the most successful and cost effective interventions in medicine. In fact, the success rate for knee replacements 10 years after surgery is 90-95%.

Of course, the decision to have knee replacement surgery should be a cooperative one made by you, your family, your primary care doctor, and your orthopaedic surgeon. The process of making this decision typically begins with a referral by your primary care doctor to an orthopaedic surgeon for an initial evaluation.

Important Safety Notes:

Knee replacement surgery is intended to relieve knee pain and improve knee functions. However, implants may not produce the same feel or function as your original knee. There are potential risks with knee replacement surgery such as loosening, fracture, dislocation, wear and infection that may result in the need for additional surgery. Longevity of implants depends on many factors, such as types of activities and weight. Do not perform high impact activities such as running and jumping unless your surgeon tells you the bone has healed and these activities are acceptable. Early device failure, breakage or loosening may occur if you do not follow your surgeon's limitations on activity level. Early failure can happen if you do not guard your knee joint from overloading due to activity level, failure to control body weight or accidents such as falls. Talk to your doctor to determine what treatment may be best for you.

The information listed on this site is common guidance and is not meant as medical advice. Every patient's case is unique and each patient should follow his or her doctor's specific instructions. Please discuss nutrition, medication and treatment options with your doctor to make sure you are getting the proper care for your particular situation.


All information provided on this website is for information purposes only. Please see a healthcare professional for medical advice. If you are seeking this information in an emergency situation, please call 911 and seek emergency help.

All materials copyright © 2015 Smith & Nephew, All Rights Reserved.


How is Knee Replacement Surgery Performed?

Knee Surgery

During knee replacement surgery, the surgeon surgically removes the damaged bone and cartilage of the joint and replaces it with smooth, artificial implants - thereby eliminating painful bone-on-bone contact.

Almost all knee replacement implants consist of a four-part system:

  • The tibial (shin) side has two elements and replaces the top of the shin bone. This portion of the implant is made up of a metal tray attached directly to the bone and a plastic spacer that provides the lower half of the new joint's bearing surface.
  • The femoral (thigh bone) side is a single element that replaces the bottom of the thigh bone and provides the top half of the new joint's bearing surface. This component also replaces the groove where the patella, or kneecap, sits.
  • Finally, the patellar component replaces the surface of the kneecap, which rubs against the femur. The patella protects the joint, and the newly resurfaced patellar button will slide smoothly on the front of the joint

Important Safety Notes:

Knee replacement surgery is intended to relieve knee pain and improve knee functions. However, implants may not produce the same feel or function as your original knee. There are potential risks with knee replacement surgery such as loosening, fracture, dislocation, wear and infection that may result in the need for additional surgery. Longevity of implants depends on many factors, such as types of activities and weight. Do not perform high impact activities such as running and jumping unless your surgeon tells you the bone has healed and these activities are acceptable. Early device failure, breakage or loosening may occur if you do not follow your surgeon's limitations on activity level. Early failure can happen if you do not guard your knee joint from overloading due to activity level, failure to control body weight or accidents such as falls. Talk to your doctor to determine what treatment may be best for you.


All information provided on this website is for information purposes only. Please see a healthcare professional for medical advice. If you are seeking this information in an emergency situation, please call 911 and seek emergency help.

All materials copyright © 2015 Smith & Nephew, All Rights Reserved.


Could You Be Allergic to Your Knee Implant?

The surprising answer to this question is yes.

Implant Allergy

While the majority of patients might not make the association between a knee implant and allergies, for anyone who has ever had an adverse reaction to things like jewelry, watches or metal buttons, the link is much clearer and more important. That's because your body's potential reaction to an orthopaedic implant may be predicted by your skin's reaction to items containing nickel or chromium - two metals present in stainless steel and in most metal knee implants. In many cases, sensitivity to these allergens has resulted in revisions for knee replacement patients.1-3

allergy chart

Although tests show that less than 10% of the population has a current sensitivity to these metals5, it is possible to develop new allergies over the course of your lifetime. And while it is not clear what triggers new allergies, studies have shown that the rate of metal allergy increases to 25% in people who have a metal implant in their body and to 60% of patients who need to have their first implant surgically replaced.6

VERILAST? Technology uses our proprietary OXINIUM? Oxidized Zirconium for the femoral - or thighbone portion - component rather than the more commonly used cobalt chrome. Our OXINIUM alloy has less than 0.0035% nickel content, and less than 0.02% chromium content compared to up to 0.5% and 30.0% respectively in cobalt chrome.7 Moreover, oxidized zirconium is a nearly inert material that has not been reported to induce immune reactions.8

allergy chart

Important Safety Notes:

Knee replacement surgery is intended to relieve knee pain and improve knee functions. However, implants may not produce the same feel or function as your original knee. There are potential risks with knee replacement surgery such as loosening, fracture, dislocation, wear and infection that may result in the need for additional surgery. Longevity of implants depends on many factors, such as types of activities and weight. Do not perform high impact activities such as running and jumping unless your surgeon tells you the bone has healed and these activities are acceptable. Early device failure, breakage or loosening may occur if you do not follow your surgeon's limitations on activity level. Early failure can happen if you do not guard your knee joint from overloading due to activity level, failure to control body weight or accidents such as falls. Talk to your doctor to determine what treatment may be best for you.

1 Niki, Yasuo et al. "Screening for symptomatic metal sensitivity: a prospective study of 92 patients undergoing total knee arthroplasty." Biomaterials 26 (2005) 1019–1026
2 Nesser, s. "Biology of foreign bodies: tolerance, osteolysis, and allergy", Total Knee Arthroplasty, J. Bellemans, M.D. Ries, and J. Victor (eds.), Springer Verlag, Heidelberg, Germany, 2005, pp. 343-352
3 Granchi, Donatella et al. "Sensitivity to implant materials in patients with total knee arthroplasties." Biomaterials 29 (2008) 1494-1500
4 Hallab NJ, Anderson S, Stafford T, Glant T, Jacobs JJ. "Lymphocyte responses in patients with total hip arthroplasty." J Orthop Res 2005; 232:384e91.
5 Hallab, Nadim et al. Metal Sensitivity in Patients with Orthopaedic Implants, The Journal of Bone & Joint Surgery, Vol 83-A No. 3. March 2001 p428-436
6 Hallab, Nadim et al. Metal Sensitivity in Patients with Orthopaedic Implants, The Journal of Bone & Joint Surgery, Vol 83-A No. 3. March 2001 p428-436
7 ASTM International Standard Specification for Wrought Zirconium-2.5Niobium Alloy for Surgical Implant Applications (UNS R60901) Designation: F 2384 – 05 and Standard Specification for Cobalt-28 Chromium-6 Molybdenum Alloy Castings and Casting Alloy for Surgical Implants (UNS R30075): Designation: F 75 – 07
8 Zardiackas, Lyle D., Kraay, Matthew J., Freese, Howard L, editors. Titanium, Niobium, Zirconium, and Tantalum for Medical and Surgical Applications ASTM special technical publication; 1471. Ann Arbor, MI: ASTM, Dec. 2005

The information listed on this site is for informational and educational purposes and is not meant as medical advice. Every patient's case is unique and each patient should follow his or her doctor's specific instructions. Please discuss nutrition, medication and treatment options with your doctor to make sure you are getting the proper care for your particular situation.


All information provided on this website is for information purposes only. Please see a healthcare professional for medical advice. If you are seeking this information in an emergency situation, please call 911 and seek emergency help.

All materials copyright © 2015 Smith & Nephew, All Rights Reserved.


Our LEGION CR Knee with VERILAST Technology was lab-tested to simulate the number of steps the average person takes in 30 years.1-7

Verilast Knee

OXINIUM + XLPE VERILAST Technology

If knee replacement is in your future, you've come to the right place to learn about one of the truly significant advancements in joint replacement materials in the past 20 years, VERILAST Knee Technology.

It's important to remember that not every knee implant is the same. VERILAST Knee Technology directly addresses one of the most commonly cited concerns associated with knee replacement implants, implant wear.

Whether or not to undergo knee replacement surgery is a very important decision. No matter how statistically safe and successful knee replacement surgery has proven to be, every surgery has risks. Before making any surgical decision, conversations should take place with your family, your primary care doctor and your orthopaedic surgeon to make sure that knee replacement with VERILAST Technology is the right course of action for your particular situation.

Important Testing Note

VERILAST knee wear testing and results apply only to the VERILAST LEGION CR Primary Knee System only. Extended lab-testing for other VERILAST knee systems have not been performed. The results of laboratory wear simulation testing have not been proven to predict actual joint durability and performance in people. A reduction in wear alone may not result in improved joint durability and performance because other factors, such as bone structure, can affect joint durability and performance and cause medical conditions that may result in the need for additional surgery. These other factors were not studied as part of the testing.

Important Safety Notes:

Knee replacement surgery is intended to relieve knee pain and improve knee functions. However, implants may not produce the same feel or function as your original knee. There are potential risks with knee replacement surgery such as loosening, fracture, dislocation, wear and infection that may result in the need for additional surgery. Longevity of implants depends on many factors, such as types of activities and weight. Do not perform high impact activities such as running and jumping unless your surgeon tells you the bone has healed and these activities are acceptable. Early device failure, breakage or loosening may occur if you do not follow your surgeon's limitations on activity level. Early failure can happen if you do not guard your knee joint from overloading due to activity level, failure to control body weight or accidents such as falls. Talk to your doctor to determine what treatment may be best for you.

  1. Goldsmith AA et al., "Comparative study of the activity of the total hip arthroplasty patients and normal subjects". J Arthrop, (16)5:613-619, 2001.
  2. Morbidity and mortality weekly report, 55(40):1089-1092, October 13, 2006.(Accessed on October 30, 2009).
  3. Gioe TJ et al., "Knee Arthroplasty in the young patient - Survival in a community registry". Clin Orthop Relat Res, 464:83-87, 2007.
  4. Wallbridge N and Dowson D. "The walking activity of patients with artificial hip joints". Eng Med 11:95, 1982
  5. Wimmer M A et al., "Joint motion and daily activity profile of total knee patients in comparison with the ISO knee wear simulator". Paper 0159, 48th ORS, 2002.
  6. Huddleston J I et al., "How often do patients with high-flex total knee arthroplasty use high flexion?",Clin Orthop Relat Res, 467:1898-1906, 2009.
  7. Naal F D et al., "How active are patients undergoing total joint arthroplasty? A systematic review", Clin Orthop Relat Res, DOI 10.1007/s11999-009-1135-9, published online: 28 October 2009.


All information provided on this website is for information purposes only. Please see a healthcare professional for medical advice. If you are seeking this information in an emergency situation, please call 911 and seek emergency help.

All materials copyright © 2015 Smith & Nephew, All Rights Reserved.

Knee Medical Team

Expert Doctors in this Area

Expert PAs and NPs in this Area of Expertise

Tammy Doering, PA-C

Tammy Doering, PA-C

Greg Harris, PA-C

Greg Harris, PA-C

Ray Lieber, PA-C

Ray Lieber, PA-C

Keri McPherson, PA-C