Is TKR surgery better than non-operative treatment for knee arthritis?
Monday, 01 July 2019, 14:16

Is it time for Total Knee Replacement (TKR) surgery?









Osteoarthritis (OA) is the third-leading cause of life-years lost to disability worldwide. By the age of 65 years half of the population have OA, and this prevalence is expecting to rise as the population ages in demographic terms. 

Nearly 1 million knee replacements (TKR) are performed annually in United States. Rates of TKR surgery tripled in the last 20 years and projections in US show further increase in demand by 6 fold (673%) by 2030.(1,2) A similar rise in TKR surgery is also expected in Ireland.


Since 1970’s, when first performed, TKR surgery has been a successful procedure that gives mobility and independence back to people suffering with knee arthritis.  However TKR surgery comes with risks. The risks of clot formation, pulmonary embolus, infection, and fracture range from 0.1 to 1.0%, with higher risks among older persons and those with a higher number of coexisting conditions.(3,4) Also, the procedure is not always successful; approximately 20% of patients after TKR have residual pain 6 or more months after surgery.(5)


There are other non-operative alternatives for treatment of moderate knee arthritis and I have written about those in a previous article - “The Young Arthritic Knee”. Clinical trials have shown that physical therapy (including exercises and manual therapies) can reduce pain and improve function in patients with moderate and advanced knee osteoarthritis.(6-8)


Until now, we have lacked rigorously controlled comparisons between TKR surgery and its non-operative alternatives. 




A prospective randomized control study is the gold standard for a clinical trial and provides the most credible evidence when assessing different treatment effects on patients. These are carefully designed and executed studies to eliminate bias and establish the best available treatment.


Recently (October 2015), New England Journal of Medicine, a highly esteemed medical journal, published a study entitled “A Randomized, Controlled Trial of Knee Replacement”. Interestingly, prior to this publication NEJM published only 4 original articles on arthroscopic knee surgery and all with ‘negative’ results. I have made reference to those articles in one of my previous article (“The Young Arthritic Knee”).


The recent study was performed by a Danish group of researchers over a number of years and involved 100 patients with symptomatic moderate and severe knee osteoarthritis.  Patients were split in two different groups and assigned to undergo either total knee replacement followed by a rigorous 12-week nonsurgical-treatment regimen (TKR group) or to receive only the nonsurgical treatment (Nonsurgical-treatment group), which consisted of supervised exercise, education, dietary advice, use of insoles, and pain medication. Improvement in pain and function was assessed at 1 year after initiating treatment to see the effect on both treatments on the similar group of patients.





TKR surgery proved markedly superior to non-surgical treatment alone in terms of pain relief and functional improvement. The percentage of patients who had a significant improvement in pain after 1 year was 85% in the total-knee-replacement group and 68% in the nonsurgical-treatment group. In fact, one in four patients in the nonsurgical-treatment group elected to have TKR before in the first year, and more patients are likely to cross over as follow-up extends further.


It is noteworthy that more than two thirds of the patients in the nonsurgical-treatment group had clinically meaningful improvements in pain and that this group had a lower risk of complications compared with the TKR surgery-treatment group.


When discussing treatment options for moderate and severe knee OA patients face choices that are associated with different levels of symptomatic improvement and risk





When compared with non-operative treatment, TKR surgery gives better pain control and better function despite the inherent higher risk of adverse events. Each patient along with their surgeon must weigh these considerations and make the decision that best suits the patient’s values and expectations.


The right time to have knee replacement surgery is when the patient is having symptoms that are affecting his or her quality of life and they want something done about it. This is a personal and very subjective decision. I always advise patients to take their time, really think it over and have surgery when it suits them.



I certainly stress to my patients that surgery of any kind carries risks and it is important for them to fully understand what they are. However, in the hands of a good surgeon, experienced nursing staff and in an excellent hospital facility, complications are unlikely.


With modern technology, implant design, materials and surgical techniques, knee replacement surgery has become one of the most successful operations available to patients with moderate or severe knee arthritis. Successful knee replacement surgery reduces or eliminates knee pain and improves joint function, enabling patients to get back to a normal active lifestyle.






  1. Agency for Healthcare Research and Quality. Healthcare Cost and Utilization Project database. 2012 (http://hcupnet.ahrq .gov/HCUPnet.jsp.)
  2. Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg Am 2007;89:780-5
  3. Kennedy JW, Johnston L, Cochrane L, Boscainos PJ. Total knee arthroplasty in the elderly: does age affect pain, function or complications? Clin Orthop Relat Res 2013;471:1964-9.
  4. SooHoo NF, Lieberman JR, Ko CY, Zingmond DS. Factors predicting complication rates following total knee replacement. J Bone Joint Surg Am 2006;88:480-5.
  5. Beswick AD, Wylde V, Gooberman-Hill R, Blom A, Dieppe P. What proportion of patients report long-term pain after total hip or knee replacement for osteoarthritis? A systematic review of prospective studies in unselected patients. BMJ Open 2012; 2(1):e000435.
  6. Jansen MJ, Viechtbauer W, Lenssen AF, Hendriks EJ, de Bie RA. Strength training alone, exercise therapy alone, and exercise therapy with passive manual mobilisation each reduce pain and disability in people with knee osteoarthritis: a systematic review.J Physiother 2011;57:11-20.
  7.  McAlindon TE, Bannuru RR, Sullivan MC, et al. OARSI guidelines for the non-surgical management of knee osteoarthritis. Osteoarthritis Cartilage 2014;22:363-88. 11.
  8. Skou ST, Roos EM, Simonsen O, et al. The efficacy of nonsurgical treatment on pain and sensitization in patients with knee osteoarthritis: a pre-defined ancillary analysis from a randomized controlled trial. Osteoarthritis Cartilage (in press).