Keeping the blood flowing

A waterfall with beautiful softness illustrating the delicacy of flow

Keeping the venous blood flowing after knee arthroplasty is vital. The image is CC by Dominik Starosz

As always it is interesting with a randomized controlled trial (RCT). I recently stumbled upon Westrich et al’s RCT on prophylaxis after knee arthroplasties. They randomized between aspirin and enoxaparin (LMWH) where both groups received mechanical pumps immediately after surgery. The difference in DVT:s was really small, 14% vs 18% in favor for enoxaparin. This was not significant in 275 patients. Continue reading

To trust or not to trust an MRI

MRI images can be hard to interpret, especially the meaning of different findings. The image is CC by Becky Stern

In my daily clinical work I’m often confronted with long descriptions of MRI exams by radiologists, and frequently my final conclusion is: nothing out of the ordinary. It is therefore nice to see articles from Felson’s team, where they try to shed some light onto the issue.

Englund et al showed previously that an ostearthritic knee early on has degenerative meniscal changes, and the MRI-findings of these often cause distress among both GP:s and patients. Guermanzi et al’s study goes even further, and examines knees without osteoarthritis (Kjellgren-Lawrence 0) to see what an MRI can say about a painful knee in patients above 50 years of age.

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Killer hip implants?

A cemitary with a lonely tree at the center

An article in BMJ indicates that the best hip implants may actually be killing patients – an outrage or a statistical fluke? The image is CC by Wayne Wilkinson

An important question was raised by McMinn et al.: Can choice of hip arthroplasty have an impact on life & death?

While uncemented total hip arthroplasty implants are very popular, they’re often slightly more expensive, have a higher risk of peroperative fractures, and a have a higher overall risk of re-operations/revisions (although this has recently been put in question, as it may be part due to a few bad implants). McMinn’s study is interesting because it might add a new dimension to the choice of implants: should we also look at the mortality rates when choosing the best implant?

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Time to change gloves?

Surgical gloves

How often do surgical gloves fail? The picture (cc) is by A.Currell

Even though minor rifts in surgical gloves happen every now and then most surgeons don’t think too much about them. A study by Carter et al. indicate that we probably should be more worried: we miss to detect about 2/3  of the perforations. In 80 % of the cases we also failed to acknowledge that also the inner glove was perforated. Not surprisingly the surgeon had the highest rate of perforations, between 4-9 %, relating to procedure difficulty. Continue reading

How hard can it be – just glue some cartilage onto the bone (part IV)

It's nice to see some real orthopaedic rocket science

It’s nice to see some real orthopaedic rocket science. The picture (cc) is by Calsidyrose

It is rare to see long term follow-up studies ( > 5 years) and Bentley et al’s randomized controlled study on cartilage defects is therefore a rare bird! They randomized 1 00 consecutive patients to chondrocyte transplantation or mosaicplasty. After 10 years they were able to follow-up 94 % of all patients – a truly amazing accomplishment!

The method for chondrocyte transplantation was “simple”: harvest a few chondrocytes from the knee, grow them in a dish and the reinsert them and cover it up with a piece of tissue so that the cells don’t escape. I guess growing the cells requires a lot of expertise but apart from that no fancy gadgets were needed. Continue reading

How hard can it be – just glue some cartilage onto the bone (part III)

A picture of jello

A picture of jello – not really like the NeoCart-jello but it’s a cool picture. The picture (cc) is by Amayzun

Today’s blog is about gluing cartilage onto trauma-caused joint cartilage defects. Crawford et al report a new treatment option where they grow chondrocytes, attach them to a soft jelly (collagen matrix) and then glue it onto the defect! They randomized 21 to the NeoCart jelly and 9 patients to standard microfracturing and followed them for 2 years. Continue reading

How hard can it be – just glue some cartilage onto the bone (part II)

A mosaic representin the number 2

When doing a mosaicplasty you create a mosaic of ostechondral cylinders. These then cover the injury and protect the bone. The picture (cc) is by L D M

Although RCT’s are the golden standard for evaluating techniques, retrospective studies such as Krych et al’s study , “Activity Levels Are Higher After Osteochondral Autograft Transfer Mosaicplasty Than After Microfracture for Articular Cartilage Defects of the Knee: A Retrospective Comparative Study”, can be an interesting read.

They compare microfracturing (se previous post) with mosaicplasty. In mosaicplasty you harvest bone and cartilage cylinders (osteochondral transfer) from sites where it’s not needed and transfer it to the injury. The technique is nice and fairly straightforward although getting all the cylinders aligned perfectly so that none are higher/lower is virtually impossible. It can also be a problem that you don’t have enough unused cartilage to harvest.

The reason why Krych’s study is nice is that they implemented a prospective register in 1999 and have therefore good quality follow-up data. I think it’s really praiseworthy that they started a registry that early. These are rare injuries – it took the team 13 years to get this article published! Continue reading

How hard can it be – just glue some cartilage onto the bone (part I)

A figure skater representing the low cartilage friction coefficient

The friction coefficient of cartilage is very similar to ­ice skating. The picture (cc) is by Tsutomu Takasu

A systematic review by Jakobsen et al (2005) found that the average study quality on treating cartilage defects (= chondral injuries, traumatic, not osteoarthritis) was just 43 out of 100. They found only 260 randomized patients! We are therefore craving for new, good research.

In the June 2012 JBJS Am issue there were two nice articles on treatment of cartilage defects and together with Bentley et al’s awesome article in JBJS Br April issue there is now some new evidence, craving comments 🙂

I’m splitting this post into several:

  1. Basics about cartilage & microfracturing
  2. Krych retrospective study (JBJS Am)
  3. Crawford’s RCT (JBJS Am)
  4. Bentley’s 10 year follow-up RCT (JBJS Br)

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Is roentgen stereophotogrammetric analysis (RSA) the new black?

A physician’s job is to avoid “trial and terror” as one of my senior colleagues taught me early on. Preventing bad implants from reaching the market is vital in orthopaedics. This is especially true since the current implants have a > 95 % 10 year survival. It is therefore great to see Göran Selvik’s RSA method (Selvik et al. 1983) generating headlines in both Acta Orthopaedica and JBJS Am.

In JBJS Am. a valuable 10 year follow-up of 41 hip arthroplasties (Nieuwenhuijse et al. 2012) validate the use of RSA. They could see an impressive correlation between micro motion at 2 years and late follow-up. About one fourth of all the cups turned out to be loose at the end of the follow-up. The C-statistic or area under the receiver operating curve statistic was 0.88 which is close to the ideal 1. The C-statistic is a measure of the specificity (that only the right patients are identified) and sensitivity (that all that later show movement actually are discovered). Continue reading

Swedish orthopaedic surgery gets a bronze

Time for some bragging: In a paper from 2010 The 100 classic papers of orthopaedic surgery you can read that Sweden comes in third when looking at the most cited articles throughout orthopaedic times 🙂

At the top is (of course) USA with 77 articles, then comes England with 10 articles and by beating Canada with 1 article Sweden gets the bronze with 5 articles. For a country with only 9.5 million inhabitants I think that it’s rather impressive. Continue reading