Total+Knee+Arthroplasty+Prognosis

 " According to the American Academy of Orthopaedic Surgeons, approximately 581,000 total knee arthroplasties are performed each year" (10). Primary indications for total knee arthroplasty include significant, disabling pain and decreased function (often caused by severe arthritis or injury). The ideal patient is older than 60 years old and less than 180 pounds. Major contraindications include infection, severe or uncontrolled hypertension, and progressive neurological disease. The four basic steps to a knee replacement procedure include preparing the bone, positioning the metal implants, resurfacing the patella, and inserting a spacer (5). The surgeon removes the damaged bone and cartilage and then positions the new metal and plastic implants to restore the alignment and function of the knee. The procedure typically takes 1-2 hours . To see a surgical animation of total knee arthroplasty, visit the following link:

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__Factors That Influence the Durability of a Primary Total Knee Prosthesis__

Failure of TKA can be problematic. Factors that can influence the durability of a primary total knee prosthesis include type of implant, age and gender of the patient, type of fixation, diagnosis, and design of the patellar component.



Survivorship of the primary knee replacements was 96% at five years, 91% at ten years, 84% at fifteen years, and 78% at twenty years.


 * __ Age: __ **

Prosthetic survivorship was significantly better for the patients who were older than seventy years of age than it was for those between the ages of fifty-six and seventy years or for those who were fifty-five years of age or less (1).

Prosthetic survivorship was also significantly better for the patients between the ages of fifty-six and seventy years than it was for those fifty-five years of age or less (1).

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">The results of this study were similar to the results that the researchers found from their previous study. They found that prosthetic survivorship for patients who were sixty years of age or older was better than that for those who were younger than sixty years of age (1). Therefore, you should be cautious when considering TKA on younger patients.


 * <span class="paragraphsection" style="font-family: Arial,Helvetica,sans-serif;">__ Diagnosis: __ **

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Survivorship was 90% for patients with osteoarthritis, 95% for those with inflammatory arthritis, 86% for those with post-traumatic arthritis, 84% for those with osteonecrosis, and 76% for those with another diagnosis (1).

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">From this data, you can see that patients with inflammatory arthritis had a significantly greater survivorship of implants when compared to the patients with osteoarthritis and those with post-traumatic arthritis. This could be due to the higher activity level for those with osteoarthritis. Those with inflammatory arthritis may also have a higher risk of failure from late metastatic infection than people with osteoarthritis (1).


 * <span class="paragraphsection" style="font-family: Arial,Helvetica,sans-serif;">__ Prior Surgery: __ **

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Survivorship at ten years was 92% for those without prior surgery compared with 86% for knees with prior surgery (1).


 * <span class="paragraphsection" style="font-family: Arial,Helvetica,sans-serif;">__ Posterior Cruciate Ligament: __ **

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Survivorship at ten years was 91% for the designs that retained the posterior cruciate ligament, 76% for the posterior stabilized implants, 93% for the constrained condylar implants, and 93% for the posterior cruciate-sacrificing designs (1).

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">This shows that posterior stabilizing designs have a significantly worse survival rate than posterior cruciate-retaining designs.


 * <span class="paragraphsection" style="font-family: Arial,Helvetica,sans-serif;">__ Design: __ **

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Survivorship at ten years was estimated to be 92% for the prostheses with a nonmodular metal-backed tibial component, 90% for those with a modular metal-backed tibial component, and 97% for those with an all-polyethylene tibial component (1).

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Survivorship at ten years was estimated to be 93% for implants with an all-polyethylene patellar component, 76% for those with a metal-backed patellar component, and 87% for those without patellar resurfacing (1).

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">At ten years, the survivorship of prostheses fixed with cement (92%) was significantly greater than that of cementless prostheses or that of prostheses with hybrid fixation (1).


 * <span class="paragraphsection" style="font-family: Arial,Helvetica,sans-serif;">__ Gender: __ **

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;"> The 93% ten-year survivorship of total knee prostheses in women was significantly greater than the 88% value for men (1).

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">A study by Liebs et al. found that although women had a greater functional limitations at the time of surgery than men, they recovered faster after TKA. Their function was similar at 12 and 24 months though. The women were also found to have greater improvement of WOMAC scores than the men (2).


 * <span style="font-family: Arial,Helvetica,sans-serif;">__ Ideal Scenario: __ **

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">A woman over the age of 70 with inflammatory arthritis with a nonmodular, metal-backed tibial component, cement fixation, an all-polyethylene patellar component, and retention of the posterior cruciate ligament (1).

<span style="color: #0000ff; font-family: Arial,Helvetica,sans-serif; font-size: 18px; text-decoration: none;">

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">The estimated five and ten-year survival rates for this ideal replacement were 99% and 98%.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 22px;">__How Age Effects Total Knee Arthroplasty (9)__

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">The Effect of Age on Pain, Function, and Quality of Life After Total Hip and Knee Arthroplasty
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">study that looked at how age affects the outcome of TKA
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;"> compared pain, functional, and health related quality of life outcomes for 2 different groups; 55-79 years old and 80 years old and over.
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Results:
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Pre and post op scores were similar between the 2 age groups
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Regardless of age, patients all had significant improvements in function, pain, and stiffness
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Both age groups had a similar number of hospital complications

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Another study that looked at differences of age groups for TKA was Total knee arthroplasty in patients over 80 years of age (11)
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Compared two different TKA groups; mean ages of the groups were 84 and 69 respectively.
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">While the older age group had a higher incidence of post operative complications, TKA has been shown to be a safe and effective treatment for patients over the age of 80.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">A third study showed that older age was not associated with worse clinical outcomes or longer recovery from surgery (5).

__<span style="font-family: Arial,Helvetica,sans-serif; font-size: 22px;">Other Prognostic Factors in a Total Knee Arthroplasty __ <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">The following is a collaboration of multiple reserach studies. The main points are listed below.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 18px;">Obesity
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">“Obesity is an independent risk factors for poor recovery in TKA (3)
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Severe obesity (BMI>35) was seen to be a risk factor to predict worse pain and functional recovery 6 months. There was no difference 3 years following the TKA. (3)
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Obese patients tend to have more surgically related complications. (3)
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Longer lengths in stay are associated with obese patients with co-morbidities like cardiac disease and diabetes mellitus. (3)
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Long term recovery for severe obese patients is slower in functional improvement. (3)
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Patients with a BMI of 35 or greater are at higher risk of complications post op including infections, which will increase their lifetime reoperation risk (6).

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 18px;">Functional Outcomes
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Preoperative TKA status was a significant predictor of higher WOMAC scores six months post-surgery (4)
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Better preoperative function is associated with better postoperative levels of function (8).

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 18px;">Improved Function From Progressive Strengthening Interventions <span style="font-family: Arial,Helvetica,sans-serif; line-height: 24px;"><range type="comment" id="233566"> []
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Article used in case study presentation from post-professional student, Natalie Garboriault-Whitcomb (12)
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Compared progressive strengthening with conventional rehabilitation
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">The progressive strengthening group demonstrated better functional performance at 12 months
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">Standard of care group data in comparison to progressive strengthening:
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;"> 24% longer on the TUG (Timed Up and Go)
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">44% longer to complete the SCT (Stair-Climbing Test)
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">15% shorter distance walked on the 6MW (6-Minute Walk)

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 18px;">Mortality
 * <span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">No study provided information on predictors of mortality after knee arthroplasty (7).<range type="comment" id="832249">

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<span style="font-family: Arial,Helvetica,sans-serif; font-size: 16px;">__<span style="font-family: Arial,Helvetica,sans-serif; font-size: 22px;"><range type="comment" id="644203">Citations __

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">1. Rand, James, Robert Truesdale, Duane Ilstrup, and Scott Harmsen. "Factors Affecting the Durability of Primary Total Knee Prostheses." //The Journal of Bone and Joint Surgery//. Feb. 2003. Web. 27 Mar. 2012. [].

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">2. Liebs, T. R., W. Herzberg, R. Kroeger, W. Ruther, and J. Hassenpflug. "Women recover faster than men after standard knee arthroplasty." //National Center for Biotechnology Information//. U.S. National Library of Medicine, Oct. 2011. Web. 27 Mar. 2012. @http://www.ncbi.nlm.nih.gov/pubmed/21698485.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;"> 3. Jones, CA, V. Cox, GS Jhangri, and ME Suarez-Almazor. "(3) Delineating the Impact of Obesity and Its Relationship on Recovery after Total Joint Arthroplasties." //Osteoarthritis Research Society// (2012). //Pubmed//. Web. @http://www.ncbi.nlm.nih.gov.proxy.kumc.edu:2048/pubmed/22395039.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;"> 4. Caracciolo, B., and S. Giaquinto. "Determinants of the Subjective Functional Outcome of Total Joint Arthroplasty." //Archives of Gerontolgy and Geriatrics// 41.2 (2005). //Pubmed//. Web. [].

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">5. American Academy of Orthopaedic Surgeons. //OrthoInfo//. December 2011. Web. 27 March 2012. [].

<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 110%;">6. Ghandi, R., D. Wasserstein, and F. Razak. "BMI Independently Predicts Younger Age at Hip and Knee Replacement." //Obesity// 18.12 (2010). //Pubmed//. Web. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">[].

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;"> 7. Santaguida, PL, GA Hawker, and PL Hudak. "Patient Characteristics Affecting the Prognosis of Total Hip and Knee Joint Arthroplasty: A Systematic Review." //Canadian Journal of Surgery// 51.6 (2008). //Pubmed//. Web. [].

<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 110%;">8. Kennedy, DM, PW Stratford, and DL Riddle. "Assessing Recovery and Establishing Prognosis following Total Knee Arthroplasty." //Physical Therapy// 88.1 (2008). //Pubmed//. Web. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">[].

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">9. Jones, Allyson, Donald Voaklander, William Johnston, and Maria Suarez-Almazor. "The Effect of Age on Pain, Function, and Quality of Life After Total Hip and Knee Arthroplasty ." //Archives of Internal Medicine//. 161.3 (2001): 454-60. Web. 27 Mar. 2012. [].

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">10. Bell, Karla A and Anna Shovestul. //Total Knee Arthroplasty.// 25 October 2011. Web. 27 March 2012. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">http://www.ptnow.org/ClinicalSummaries/QuickDetail.aspx?cid=96cc5bc9-263e-4b40-b388-a9b086981640

<span style="font-family: Arial,Helvetica,sans-serif;">11. Stroh, D Alex. "Total knee arthroplasty in patients over 80 years of age." //The Journal of Knee Surgery// (2011): 279-283. Web. 27 March 2012. http://www.ncbi.nlm.nih.gov.proxy.kumc.edu:2048/pubmed?term=22303757

12. Petterson, Stephanie C. "Improved function from progressive strengthening interventions after total knee arthroplasty: a randomized clinical trial with an imbedded prospective cohort." //Arthritis and rheumatism// (2009): 174-183. Web. 27 March 2012. http://onlinelibrary.wiley.com.proxy.kumc.edu:2048/doi/10.1002/art.24167/full.