Few topics in knee replacement have generated as much controversy as the topic of patella resurfacing. Every surgeon literally has his own view. The world has three types of surgeons.Those that resurface always, those that never resurface and the 'selective resurfacers'. The last group think they are the smartest (I wish that were true!!) The literature obviously has articles in favour of all three groups.
Resurfacing theoretically reduces anterior knee pain, improves quadriceps strength and stair climbing ability. But it brings with it its own set of problems like patellar instability (subluxation and dislocation), fracture, wearing/loosening of the patellar component, patellar clunk and patellar ligament tear.
So lets see if I can put some sense in this chaos. With controversial topics, reviews and meta analysis are the best bet.
The most recent meta analysis is from China by He Jy et al published in KNEE in 2011. They concluded that not resurfacing the patella, increased the risk of re operation for patello femoral problems significantly. Importantly there was no difference between the two groups in terms of anterior knee pain rate, knee pain score, knee society score and knee function score. And analysis of high quality studies showed no advantage of resurfacing.
Another review from China published in 2011 had the same conclusion. There is an increased risk of re operation. This suggests that, if the patient has post-op anterior knee pain and the surgeon finds the patella unresurfaced, he will most probably open the knee!! This remains a non evidence based practice as was proved by Burnett and Bourne in 2004. They stressed that many factors play a role in the development of anterior knee pain after surgery and it should not be assumed that the pain is from the unresurfaced patella.
So the way I see it, both options work! However there is a slight trend in literature in favour of resurfacing.
Surgical technique (as usual) remains the most important variable to eliminate complications after resurfacing.
In cases where the patella is not resurfaced, the temptation to re operate for patello femoral problems should be resisted. In all probability the re surgery will fail.
And a word of caution for the 'smart selective resurfacers' - there are no proven pre or intra op criteria to decide which patellae to resurface!
Happy Replacing !
Dr Qaed Dhariwal
MS Ortho
Specialist in Joint Replacement
qaedjohar@gmail.com
Resurfacing theoretically reduces anterior knee pain, improves quadriceps strength and stair climbing ability. But it brings with it its own set of problems like patellar instability (subluxation and dislocation), fracture, wearing/loosening of the patellar component, patellar clunk and patellar ligament tear.
So lets see if I can put some sense in this chaos. With controversial topics, reviews and meta analysis are the best bet.
The most recent meta analysis is from China by He Jy et al published in KNEE in 2011. They concluded that not resurfacing the patella, increased the risk of re operation for patello femoral problems significantly. Importantly there was no difference between the two groups in terms of anterior knee pain rate, knee pain score, knee society score and knee function score. And analysis of high quality studies showed no advantage of resurfacing.
Another review from China published in 2011 had the same conclusion. There is an increased risk of re operation. This suggests that, if the patient has post-op anterior knee pain and the surgeon finds the patella unresurfaced, he will most probably open the knee!! This remains a non evidence based practice as was proved by Burnett and Bourne in 2004. They stressed that many factors play a role in the development of anterior knee pain after surgery and it should not be assumed that the pain is from the unresurfaced patella.
So the way I see it, both options work! However there is a slight trend in literature in favour of resurfacing.
Surgical technique (as usual) remains the most important variable to eliminate complications after resurfacing.
The correct patellar component size, the proper thickness of the cut, medial placement of the patellar component, rule of no thumb and lateral retinaculum release when needed, should be followed when performing patellar resurfacing during TKR.
And a word of caution for the 'smart selective resurfacers' - there are no proven pre or intra op criteria to decide which patellae to resurface!
Happy Replacing !
Dr Qaed Dhariwal
MS Ortho
Specialist in Joint Replacement
qaedjohar@gmail.com
The patella remains an unsolved problem and generates controversy even today!
ReplyDeleteHowever in the Indian context the bones are usually porotic and the bone stock is usually less when compared to the Caucasian population.
In my personal experience a patellaplasty gives good consistent results.
In this procedure I would recommend shaving the poles of the patella with a controlled saw gesture to make it flush with the tendon of the Qx. Any circumferential osteophytes can be removed.I also use cautery around the patella to denervate it.
If there are any chondral blisters or defects then these can be debrided or drilled.
In this way with modern implants having deeper trochleae and left and right femur implants the patellofemoral joint remains congrous and symptomfree.
One must also ensure that the knee replacement procedure is done with minimal soft tissue trauma and balanced gaps.
Success is always ensured!
Happy Replacing indeed!
thats a great topic and a good forum.
ReplyDeleteI almost never resurface the patella except in RA patients.
Also in most of my patients the thickness of patella is mostly around 19 mm + - 2 mm. also in some RA + ladies the thickness is even lesser. I have left them un-replaced. still have not faced problems.
Comments from Quad and Kiran
True Qaed, patella does present a vexing issue in TKA's and being "selective" is the way to go as aptly summed up by you.However, of the various surgical steps mentioned like medialization of patella or need for lateral retinacular release to ensure better tracking,the most vital aspect would be achieve accurate rotational orientation of your femoral and tibial components. If the patella maltracks during your trial check,one needs to go back to review and correct malrotation.Unfortunately lateral retinacular release is just a cosmetic solution to a graver underlying problem.
ReplyDeletehi sinu, what you said about the lateral retinacular release is very true. recently learned a way to solve slight lifting of medial facet of patella while doing a trial check; learned it from dr rajgopal, he removes a 3-4 mm of lateral edge of patella in such cases, and the patella tracks beutifully.
ReplyDeleteI dont resurface patella. So far no problem.
ReplyDeleteAs for removing 3-4mm of lateral edge of patella for better patellar tracking, it is a novel idea !