Partial Knee Joint Replacement

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Dr Sean Mackay: Today I’d like to welcome to the PodMd studio Dr Saeed Asadollahi, Saeed is an orthopaedic surgeon in Victoria. His specialty/ special interest involves hip and knee arthroplasty, partial knee replacement and revisions, trauma (all aspects of adult and paediatric)

Question1
The topic of today’s discussion is on partial knee replacement

Saeed, can you describe for our listeners what is involved in a partial knee replacement?

Sure. A partial knee replacement is a surgical procedure for relieving disability and arthritic knee pain trauma to the remaining healthy bone and soft tissue is reduced during a partial knee replacement because only the damaged surface of the joints are replaced. And that’s a big advantage compared to a fully replacement with everything in the knee will be replaced, including the knee cap. Most of the times, I think this is an excellent question. The most common presenting symptom is pain over the medial or inside aspect of the knee, which interferes with people’s activities of daily living. This includes eye pain. When people try to manage a flight of stairs, a walking example to do their shopping, or simply rising from a chair, the pain can also sometimes interfere with the night’s sleep. A significant number of patients have difficulty kneeling down or when they try to get up after that, occasionally I see patients who also experience mechanical symptoms such as giving by clicking and locking because of the knee colitis.

Question 2 
How would a patient needing a partial knee replacement typically present?

That’s a great question, Sean, the presenting complaint, which is usually pain and the degree of stiffness along with findings on the weightbearing X Ray, which are reduced joint space osteophytes involving the medial or lateral compartment, we’ll confirm the diagnosis uni compartmental knee replacement is indicated only when one out of the three compartments of the knee joint is involved. So if we have more than one compartment involved, for example, a bar compartment or try compartmental disease, then unfortunately patient cannot have a union compartment to knee replacement. So preoperative, extra weight bearing X Ray would be crucial.

Question 3
How would a GP initially know if a patient would need a partial or total knee replacement?

Look, I think this is a fantastic question. The only recommendation that I have is avoiding surgery. If the radiographic changes do not show bone and bone changes in simple words, if they are Titus is not bad enough, I’ll repeat that if the R truck is, is not bad enough, I don’t think the patient should have either a partial or full knee replacement. And the reason for that is there are multiple studies which have shown in the lack of presents of a bone on bone arthritis. The outcome of knee replacement can be unpredictable. So if a patient presents with some arthritis involving the knee and he or she has got symptoms consistent with them, I strongly recommend trying the non-operating pathway first and then referring patient to us.

Question 4
What is the most common cause of a total knee replacement?

This is excellent. The most common cause of partial knee replacement universal in Australia is actually osteoarthritis involving only one compartment of the knee. That much less common causes would be osteonecrosis of the femoral condyle and in rare cases, a secondary osteoarthritis after trauma. But I would say at least 97% of cases who ended up having a partial knee replacement just fall into the category of primary osteoarthritis involving the knee joint.

Question 5
What is the prehab and rehab like?

For preparation for the surgery, patients will have routine preoperative blood tests that would include full blood count electoral laws, coagulation profile. If the patient is on any blood thinners and MSU of the urine to ensure patient doesn’t have a concurrent UTI, the radiographic series will need to be completed. And that includes getting a full weight bearing X Ray of the knee joint, as well as the skyline view in the pre-admission clinical nursing staff arranged for ACG and chest xray.
And finally, our anaesthetist will see the patient before the surgery. As far as the post operative phase go, we will have postoperative care program in place to help the patient to recover after the surgery. Post-surgery, they’ll be encouraged to walk and try to bend their knee as much as they can in terms of bending the knee. It’s not super critical in the setting of a partial knee replacement because we’ve noticed that in the first two or three days, excessive knee bending can cause excessive pain. And that causes some inhibition in terms of adhering to the exercises. But I would encourage patients to try to bend any knee as soon as they can, as much as the pain allows and depending on the social situation and the postoperative conditions people will have. Usually one or two days of hospital stay. Um, a positive attitude is shown to be critical in terms of having a successful recovery. It’s not uncommon to see patients who get a partial knee replacement and go home same day

Question 6
How can a GP aid in the surgery, treatment or recovery for a patient getting a partial knee replacement?

I think the GP role is fundamental appropriate assessment by getting weight bearing X Ray of the knee, and also getting an a skyline view of the patella will confirm or rule out the diagnosis. Once we’ve diagnosed a uni compartmental involvement of the knee joint temp, we need to find out whether there are bone on bone changes or it’s just a partial thickness boneless. Regardless of the, the two that I explained, I think the first phase of treatment would be a trial of non operative treatment, which will be medications, anti-inflammatory tablets and physiotherapy. I think operative and surgical treatment comes into action and becomes a choice only if a nonoperative treatment has been trolled and fight, and we’ll be delighted to help them with that.

Thank you for your time here today in the PodMD studio. To sum up for us, could you please identify the three key take home messages from today’s podcast on a partial knee replacement.
Yeah, I would say the partial knee replacement is really indicated in selected group of patients with osteoarthritis of the knee where only one compartment is involved.
It’s not the operation for every month with knee osteoarthritis patients have a significant, faster recovery compared to total knee replacement, and they can go back to the activities of daily living that enjoy. They enjoy such as golfing and swimming.
General practitioners can help us identifying this group of patients who will benefit from the surgery by organizing weightbearing X rays of the knee skyline view of the patella and initiating the trial of non-operative management.

Thanks for your time and the insights you’ve provided.

Thanks Sean. I appreciate it.