Total Knee Replacement surgery has excellent results as management of end-stage painful knee conditions such as arthritis, with dramatic improvements in quality of life scores seen following successful surgery.
Total Knee Replacements last a long time. The Australian National Joint Replacement Registry documents that almost 95% of Total Knee Replacements implanted ten years ago have not required revision surgery(1). The knee replacement that I typically use is considered to have a low revision rate that is statistically the same as other well functioning Total Knee Replacements(1).
Total Knee Replacement components can be fixed to the bone by either using bone cement or by press-fitting and waiting until the bone grows onto the prosthesis. My preference is to use bone cement because cemented Total Knee Replacements have been shown to achieve more reliable and predictable fixation than cementless (or uncemented) Total Knee Replacements when very large numbers of joint replacements are studied(1-4).
Knee replacements have been used to treat painful knee conditions such as arthritis for a long time. Total knee replacement was first used routinely in the 1960’s and evolved rapidly through the 1970’s and 1980’s to become a successful and reliable operation. Further advances over the past 20 years have further improved the outcomes of total knee replacement surgery.
The native knee is a complicated joint. During flexion the knee hinges, rotates and translates in a complex motion, guided by complicated joint architecture, ligaments and muscles. During total knee replacement the arthritic bone is removed and replaced by artificial components. During the surgery it is necessary to remove some of the ligaments; often these ligaments have already been irreparably damaged by the underlying arthritis. Because of this, and because knee replacement components are currently unable to perfectly replicate the complicated native knee joint architecture, most patients who have had a knee replacement are aware of their new knee during normal activities. It is normal, and common, to experience clicking in a knee replacement.
Computer Navigation for Total Knee Replacement
Recent advances in component positioning have improved patient satisfaction following total knee replacement so that up to 95% of patients can be expected to be satisfied with their new knee(5). My preference is to use computer navigation to assist in accurate component position as this facilitates surgery to be truly tailored to your knee by allowing changes to component position to be made with confidence during the surgery. Custom cutting blocks have been shown to assist in accurately positioning components but they do not allow changes during the surgery(5). Traditional techniques used for component positioning are associated with reduced patient satisfaction rates of approximately 80%(6-8).
The computer navigation system I use (Articular Surface Mapping) is not associated with any increased surgical risks and does not require a longer incision or any additional incisions when compared to traditional techniques. While it may increase the operative time by a few minutes I believe this is a worthwhile investment to improve patient satisfaction.
References
- Graves S, deSteiger R, and Davidson D, Hip and Knee Arthroplasty. Annual Report 2012. Australian National Joint Replacement Registry, 2012: p. 1-220.
- Ellams D, et al., National Joint Registry For England and Wales. 2011: p. 1-173.
- New_Zealand_Orthopaedic_Association, New Zealand Joint Registry 12 year Report. 2011: p. 1-139.
- Register SHA, Annual Report 2008 (English). Swedish Hip Registry, 2010: p. 1-126.
- Howell SM, et al., Results of an initial experience with custom-fit positioning total knee arthroplasty in a series of 48 patients. Orthopedics, 2008. 31(9): p. 857-63.
- Bourne RB, et al., Patient satisfaction after total knee arthroplasty: who is satisfied and who is not? Clin Orthop Relat Res, 2010. 468(1): p. 57-63.
- Noble PC, et al., The John Insall Award: Patient expectations affect satisfaction with total knee arthroplasty. Clin Orthop Relat Res, 2006. 452: p. 35-43.
- Robertsson O, et al., Patient satisfaction after knee arthroplasty: a report on 27,372 knees operated on between 1981 and 1995 in Sweden. Acta Orthop Scand, 2000. 71(3): p. 262-7.