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Dr Simon Coffey is an orthopaedic surgeon in Sydney, Australia. He specialises in Hip and knee surgery, and has a particular interest in sports related injuries, hip and knee reconstructive surgery and joint replacement.
When performing Total Knee Replacement it is important to have the implants well aligned. This enables the weight bearing axis to fall evenly through the implant, and thus ensure its longevity.
In much the same way as poor wheel alignment in your car causes uneven tyre wear, if your knee replacement is poorly aligned it can result in early failure and an uncomfortable or unstable knee.
Computer Navigation allows the surgeon to use a computer and associated graphical representation on a monitor to more closely and reproducibly align the components well. The surgeon can also record this data so that proof of alignment is seen.
Computer navigation is especially useful in cases where past surgery or injury has distorted anatomy, making conventional techniques difficult or impossible.
Generally, it is safe to travel long distances by plane from 6 weeks post joint replacement. This seems to be the higher risk period for complications such as Deep Vein thrombosis (DVT) and Pulmonary Embolus (PE). After 6 weeks, the risk has returned to normal background levels. Of course, all patients present different individual risk profiles, and the specific issue of travel after joint replacement should be discussed with your surgeon.
Recently there has been discussion of the role of knee arthroscopy in the presence of degenerative osteoarthritis. This has led to some confusion among patients and doctors as to when such surgery is suitable, and when it should be avoided.
The Australian Knee Society through the Australian Orthopaedic Association has published a document dealing with some of these issues. Some relevant findings are as follows:
Arthroscopic debridement, and/ or lavage, has been shown to have no beneficial effect on the natural history of osteoarthritis, nor is it indicated as a primary treatment in the management of osteoarthritis. However, this does not preclude the judicious use of arthroscopic surgery, when indicated, to manage symptomatic coexisting pathology, in the presence of osteoarthritis or degeneration.
When is knee arthroscopy appropriate?
There are certain clinical scenarios in which arthroscopic surgery, in the presence of osteoarthritis, may be appropriate – albeit after considered discussion with the patient. These include, but are not necessarily limited to, the following:
- known or suspected septic arthritis
- Symptomatic meniscal tears after an appropriate trial of non-operative treatment
- Symptomatic loose bodies
- Locked or locking knees
- Meniscal tears that require repair
- Inflammatory arthropathy requiring synovectomy
- Synovial pathology requiring biopsy or resection
- Unstable chondral pathology causing mechanical symptoms
- As an adjunct to, and in combination with, other surgical procedures as appropriate for osteoarthritis: for example high tibial osteotomy and patellofemoral realignment
- Diagnostic arthroscopy when the diagnosis is unclear on MRI or MRI is not possible, and the symptoms are not of osteoarthritis
When to Proceed?
The paper ends by stating that decision to proceed with arthroscopic surgery in the presence of osteoarthritis or degeneration should be made by the treating orthopaedic surgeon:
- After careful review of the clinical scenario: particularly the assessment of the relative contributions of the osteoarthritis, and the arthroscopically treatable pathology, to the patient’s symptoms
- With knowledge of the relevant evidence base, as listed in this document
- After an appropriate trial of non-operative treatment
- After thoughtful discussion with the patient about the relative merits of the procedure versus ongoing non-operative treatment
Over the past few months I have been travelling a lot, both within the country and overseas.
In May I travelled to Ho Chi Minh city in Vietnam to assist in education for some of the local orthopaedic surgeons. Ceramic hip replacement has been introduced into Vietnam, and I was part of a group to assist that process. In addition to some lectures, we performed two hip replacements as part of the training and education process.
Shortly after that it was down to Melbourne to examine for the Royal Australasian College of Surgeons. Four days of tough examination for the candidates.
In June it was off to Lyon, France for ISAKOS (International Society of Arthroscopy Knee Surgery and Orthopaedic Sports Medicine) Meeting. This is a sports and knee surgery meeting held every two years and was a great programme showcasing latest thinking and techniques.
I am often asked whether patients should have a partial knee replacement as it is seen to be less invasive to the patient, giving a faster recovery and better function.
Before answering this question, it is best to understand the fundamental differences between the two types of prostheses.
A partial knee replacement is designed to treat a localised area of knee arthritis, preserving less worn ligaments and bone. Usually the medial, or inner, joint between tibia and femur is resurfaced. The benefits are that more of the patients tissues are retained, speeding recovery and reducing blood loss. After recovery, function is often closer to that of a ‘normal’ knee.
In a total knee replacement, all surfaces of the joint are resurfaced (patellofemoral, medial and lateral tibiofemoral). This option has stood the test of time to offer long term pain relief and functional improvements.
The key to successful outcomes with partial knee replacement is patient selection. If strict inclusion criteria are used, partial knee replacement can offer near normal function with excellent durability. Alternatively, if arthritis in the rest of the knee is quite advanced, then the longer term results deteriorate, occasionally requiring revision total knee replacement.
Partial Knee Replacement.
Total Knee Replacement
Discussion with your surgeon as to which option is best for you is important. Some patients are best suited to a total knee replacement rather than a partial knee replacement as a successful total knee replacement is always better than a painful partial knee replacement.
Computer navigated total knee arthroplasty is a proven and useful technique to help plan, execute and document knee replacement procedures. During the operation, the surgeon digitises preoperative information about alignment and instability and then plans the appropriate surgery in real time on the computer. The surgeon then places cutting jigs on the bone according to the accurate planning that has just taken place.
The advantage of computer navigated knee replacement is to improve the accuracy of the procedure, with potential improvement in both short and long term outcomes.
Dr Coffey has been using computer navigation techniques in Knee replacement for over ten years and sees the technique as a useful tool in delivering accurate and safe surgery.
The figure below shows the range of motion and stability parameters of a knee before replacement surgery. It confirms a varus (bowed) knee with poor movement.
After surgery, the knee moves better and demonstrates a more normal alignment.
Surgeons and patients benefit from the information computer navigation brings to the operating theatre.
I recently travelled to Chengdu, China for the recent APAS (Asia Pacific Arthroplasty Society) meeting. This was an international meeting, hosted by the West China University Hospital and co-chaired by Prof Pei Fuxing. I was privileged to co-chair the scientific committee where a prestigious international faculty from the U.S., U.K, China, Korea, Pakistan and India, as well as Australia met to discuss latest trends and current thinking in hip and knee replacement. A particular emphasis of the APAS 2014 meeting was to highlight the education of orthopaedic joint replacement surgeons in China, India and other parts of the rapidly growing Asian orthopaedic community.
Chengdu is a fascinating city, home to the Panda and Hot Pot, which is one of China’s fastest growing hubs.
Following the meeting I had the opportunity to travel to Guan An, a smaller city 3 hours drive from Chengdu where I gave a lecture on Revision Hip Replacement. After this I visited the Kwong Wah Hospital in Hong Kong to meet with Dr William Chan. Four years ago I performed surgery and lectured with Dr Chan and this time had the opportunity to meet our patient from 4 years ago.
Hospital entrance in Guan An, Schezuan Province, China