Sunday, February 24, 2019

My Patient Had A Microfracture Done In The Knee

Articular cartilage is white, with the bone exposed
A fellow physiotherapist who works in a hospital came to see me after a microfracture procedure done on her knee. There was a grade 4 articular cartilage defect on her knee and this led to swelling and pain while climbing stairs and after weight training.

Outerbridge articular cartilage classification
All of us have a layer of articular cartilage covering the ends of  our bones, especially the joint surfaces. It is normally tough and resilient. This helps to protect the joint during load bearing and reduce friction during movement. Injury or damage to the articular cartilage can result from trauma (during sports) or from daily wear and tear. As articular cartilage has poor/ no blood supply, it does not heal well after injury.

There is no standard and uniform approach to managing articular cartilage injuries in the knee. Left untreated it can progress to significant joint destruction. The patient may then need a total knee replacement in the worse case scenario.

Treatment options include microfracture, arthoscopic drilling, mosaicplasty and chondrocyte transplantation to restore the joint surface.

A microfracture technique is where the surgeon performs key hole surgery to cause bleeding on the bone surface to promote healing (picture below). It is performed by the surgeon puncturing holes in the subchondral bone layer to allow bleeding to occur.  After the blood clots and heals, a layer of fibrocartilage is formed. This technique was first made popular more than 20 years ago by Dr Richard Steadman from Vail, Colorado who has since retired.

My patient had the microfracture procedure done (in the picture above) and as you can imagine, the rehabilitation to return to sport can be lengthy. There is usually a period of non weight bearing for the first six to eight weeks to allow healing while using continuous passive motion (CPM)  machine at night. Use of the CPM machine is to stimulate movement to enable nutrition in the articular cartilage since the patient is non weight bearing. Yes, correct movement is necessary for our articular cartilage to recuperate.

Most surgeons here do not usually suggest use of the CPM machine after performing the microfracture technique which I feel is critical in order for optimal healing to occur in the articular cartilage.

Lots of patience and consistency are required by the patient and physiotherapist to slowly regain functional range of movement and strength before any return to sport work can be done.

Fortunately, articular cartilage injuries are my area of interest having had them myself (and requiring 3 knee surgeries) and my postgraduate research was in this area.

I'll write more about mosaicplasty and and the chondrocyte transplantation procedure in the next post. Stay tuned.


Hurst JM, Steadman JR et al (2010). Rehabilitation Following Microfracture For Chondral Injury In The Knee. Clin Sports Med. 29(2): 257-265. DOI: 10.1016/j.csm.2009012.009.

Steadmann JR, Rodkey WG et al (1997). Microfracture Technique For Full-thickness Chondral Defects. Oper Tech Orthop. 7:300-304.

Here's what the surgeons use to cause bleeding in the bone

Sunday, February 17, 2019

Is CrossFit Safer Than Running?

Picture by Kylie Siu 
There, I thought that headline will catch your attention. More on that statistic later in the article.

CrossFit comprises of calisthenics, Olympic weightlifting, powerlifting, plyometrics, high intensity interval training (HIIT), gymnastics, running, rowing and other exercises. Participants complete daily WODs (workouts of the day) to build cardiovascular endurance, stamina, strength, flexibility, power, speed, agility etc.

CrossFit Inc was founded by Greg Glassman and Lauren Jenai in 2000 in Santa Cruz, California. It was started earlier as Cross-Fit In 1996. After the couple fell out, Glassman bought over her share with a huge loan.

CrossFit was also made popular by military personnel, law enforcement agencies, fire departments etc who can do WODs anywhere by accessing it online.

I've seen many CrossFit athletes come to our clinic, mostly by word of mouth referral. I'm told by some of them that they like to see me because I don't ask them to stop training as they're often when they see someone else when they have an injury.

Other doctors and other health care practitioners often tell them that CrossFit has a high risk of musculoskeletal injury. I usually allow them to train (modified of course) while getting them better. One such patient asked if I can write about CrossFit injuries.

So here's what I found from published articles. Those of you reading this because of the title, thank you for reading this far.

Most of the research suggest that CrossFit is not more dangerous than other strength based training. like weight or power lifting. Researchers found CrossFit results in roughly 2.1 injuries per 1000 training hours. It was actually higher for endurance sports like running. Recreational running resulted in 8 injuries per 1000 hours of training. For novice runners the figure shot up to 18.

Athletes new to CrossFit (less than 6 months) were definitely injured more often. This finding is important and coaches and athletes need to focus on correct movement patterns. Workouts need to be modified for beginners.

Common injury locations were in the knee, lower back and shoulder. Majority of the injuries were reported as chronic/ overuse in nature. Possible causes included bad/incorrect form to lift a heavier weight, fatigue, old injury and too little/ bad coaching.

Because the WODs were constantly changing and varied, CrossFit athletes are often sore or will have some discomfort from training. This can result in an inability to do the next day's workout fresh, resulting in a higher chance of injury.

Majority of injuries we see in our clinics tend to be chronic/ overuse in nature. They can definitely be remedied by coaches through modification of complexity, volume and intensity of workouts. The healthcare practitioner treating such athletes will need to modify their training around their current injuries. A simple example is an athlete with a Right lower limb injury is still able to continue CrossFit by training the upper body and L lower limb.

Bear in mind that CrossFit for general strength and fitness is different from competing in CrossFit competitions. While competing, you need to go all out with fixed weight and exercises. When performing workouts for general fitness, you can reduce the weight, drop the reps or change to a similar but less technical exercise.


Claudino JG, Bourgeois F et al (2018). CorssFit Overview: Systematic Review And Meta-analysis. Sports Med Open. 4:11. DOI: 10.1186/s40798-018-0124-5.

Mehrab M, De Vos R et al (2017). Injury Incidence And Patterns Among Dutch CrossFit Athletes. Orth J Sp Med. DOI:

Poston WSC, Haddock CK et al (2016). Is High Intensity Training(HIFT)/ CrossFit Safe For Military Fitness Training. Mil Med. 181(7): 627-637. DOI: 10.7205/MILMED-D-15-00273.

Monday, February 11, 2019

Carbon Fiber Bikes Failure

See the fork break
If you're a cyclist in Singapore, you would have probably seen the pictures of yesterday's crash from the failure of a carbon fiber fork. The fork snapped when the rider attempted to sprint. His teammate crashed as a result and broke his collar bone. Thankfully only one rider hurt.
Another look 
It looked like the epoxy bonding came off on one side of the fork and then the other side of the fork snapped. The cyclist is from the Integrated Riding Club and they were using Boardman bike frames previously. They just changed sponsors to this current 2019 Genesis frame.

Almost everyone who likes high performance bicycles uses a carbon fiber bike now. It's considered the norm and a wonder material since it's strong and extremely light to boot. Downside is damage to bikes with carbon fiber frames and/ or components can be hard to spot and potentially catastrophic as seen in the crash yesterday.

Of course these kinds of accidents are rare though they do happen. There was an article from Outside magazine last year highlighting other examples of carbon fiber bikes failing seemingly out of nowhere.

I spoke to Kenneth Tan from Cycleworx yesterday and he said that carbon fiber technology is "very advanced" now and not so prone to failure. In most cases, it's probably a legitimate design or manufacturing defect in the carbon fiber that leads to failure under normal conditions. Problem is it's difficult to see cracks with the naked eye before the cracks get worse and fail big time often without warning.

Kenneth says shoddy manufacturing and especially counterfeits, bikes that look like a "real" Pinarello (that Cycleworx is the agent) are the real problems. Counterfeit bikes pose a much greater risk than factory defects from a reputable brand. For those of you who don't know, Pinarello bikes are the Crème de la crème of bicycles. I've been going to Cycleworx since they opened in 1996 at the first Cycleworx location at Serangoon Gardens. And I used to ride a Fondriest and Pinarello before.

If you crashed your bike or plan to get a used carbon fiber one, get it checked by an expert. A foolproof test is to get an ultrasound scan done, but's it's pricey and not easily available here anyway. A simple test may be using a coin to tap the carbon fiber. When there's a defect in the carbon fiber it sounds a little flat compared to a "solid" sound.

Don't get me wrong, I'm not saying you need to abandon carbon fiber bikes. You just need to be aware that carbon fiber bikes need regular inspections and maintenance. Read the owner's manual and don't overtighten carbon fiber components (I'm sometimes guilty of that as I'm fearful of parts loosening and maybe causing a fall).

Me? I'm a fan of steel bikes although I do use a carbon fiber fork and seat post. Make sure you stay safe on the roads.
Steel is real for me
*From the Outside Magazine article.

"There's already a cottage industry of people who specialise in lawsuits resulting from bike accidents, including a growing cadre of attorneys and forensic experts who specialise in carbon fibre. Now that use of the material, once reserved for high-end bikes, has become widespread in the bike industry, reports of accidents and mysterious failures are on the rise. Kowal's case signals that bike manufacturers - even overseas brands - may be accountable. The result could be a dramatic spike in the number of lawsuits brought against makers of carbon fibre bike parts".  

Saturday, February 9, 2019

Trade Offs In Triathlon Training

The fastest triathlon bike?
I did my first triathlon when I was 16 years young. Coming from a cross country/ track and field background, my strongest leg was naturally the run. Though I finished somewhere in the middle of that race (there was only the open category then), I ended up with a run time that was among the top ten fastest.

My swim and bike time was closer to the bottom half naturally. Yes, I learnt to swim when I was seven and definitely rode a bike from time to time, but my  swim/ bike timings in that race was not fast as I didn't have the specific training that I put in as a runner. Slow transitions and fumbling with my cycling cleats didn't help either.

It isn't surprising then that a particularly good performance in my run section will come at the cost of sub-par performances in the other two disciplines.

That's what I tried to explain to one of my triathlete patients (who swam competitively in school) who had an unusually fast swim but slower than normal bike and/or run splits in a recent race. Of course it may also be a simple question of pacing.

Other reasons may be genetic. His broad shoulders may work against him on the bike especially in the aerodynamics area and run for carrying the extra muscles in the upper body.

Unless you are a professional athlete, there will be a finite amount of time and energy to train. If you spend too much time on one discipline, it will be at the expense of the other two.

Sometimes, we don't observe the trade offs due to the "big houses, big cars" effect (Van Noordwijk and de Jong, 1986). Just because someone who spends a lot of money on a fancy car does not mean he/ she will not have enough money left to buy a fancy house and vice versa. In reality, we do know people who can afford big houses and many fancy cars to boot.

This scenario is usually more obvious in slower triathletes compared to faster triathletes in Ironman distances. For the triathletes with slower finishing times, faster than average bikers are very likely to have slower than average run splits and vice versa.

This is less likely as the overall finishing times get faster. In male triathletes who are capable of finishing sub nine hours, those with a faster than average bike split are also likely to have a faster than average run split. These are your athletes who can afford the "big fancy houses and big fancy cars".

The above pattern emerges when comparing different triathletes, and this may reflect differences in innate talent and/ or training levels.

However, while comparing multiple races from a single triathlete, results suggest that pacing strategies are more important. What researchers found in slower triathletes was recording a faster than usual bike time was associated with a slower than faster run time and vice versa.

The faster triathletes were not subject to this pattern. A good time on the bike did not necessarily mean a good or bad run time.

Exceptions are when you have a very good bicycle (a form of resource allocation) which can provide aerodynamic and mechanical advantages that don't have a trade off elsewhere (except your wallet).

Here's the simple truth, for mere mortals with normal jobs, with children especially, it's pretty much impossible to reach the starting line of an Ironman with sufficient / optimal preparation for all three disciplines.


Calsbeek R and Careau V (2019). Survival Of The Fittest: The Multivariate Optimization Of Performance Phenotypes. Med Sci Sports Ex. 51(2): 330-337. DOI: 10.1249/ MSS. 0000000000001788.

Van Noordwijk AJ and de Jong G (1986). Acquisition And Allocation Of Resourses: Their Influence On Variathlon In Life History Tactics. The Am Naturalist. 128(1): 137-142.

Me (left) at the 2005 SEA Games triathlon event
When I was racing, during my peak training periods, I swam up to 20 km, rode 400 km and ran 70 km a week. All this for Olympic distance racing.

I'll wake up at 4.20 am, eat a little before leaving at 4.50 am. I'll ride to the pool where we plunge in at 5.30 am sharp. This was when I swam with Joseph Schooling, Quah Ting Wen etc under Centre of Excellence (COE) coach John Dempsey. We usually end at around 7 am after which I'll ride my bike to work at the old National Stadium. (Sometimes I have to treat some of my fellow swimmers before going to work).

If I'm up to it I would do a short run before showering and seeing my first patient at 8.30 am. This was when I was working full time as a physiotherapist at the Singapore Sports Council (Sport Singapore now).

No children then and a very understanding wife definitely helps. And we definitely didn't have a big house or a fancy car then and even now. We only bought a three year old car after my first boy turned one.
Here's a closer look at my bike then

Monday, February 4, 2019

Leg Length Discrepancy?

I've seen many patients come to our clinic being told by another health care practitioner they saw previously that they have an "obvious" leg length discrepancy. Meaning one leg is longer than the other. The patients are often worried about their difference in leg length and are usually prescribed orthotics by the doctor, physiotherapist, chiropractor, osteopath, podiatrist etc.

Remember my patient with collapsed arches? She was prescribed two pairs of orthotics and told that if they failed to help her, she will require surgery.

I usually just shrug my shoulders and explain it's not that big a deal usually. Almost everyone will have one leg longer or shorter than the other. It's perfectly normal. Don't believe anyone who tells you that it is abnormal. Nobody is perfectly symmetrical. My right leg is half a centimeter longer than my left. But my left foot is slightly longer than my right.

ASIS to medial malleolus
Some people measure a person's leg length from the umbilicus to the medial malleolus. Here's how I measure a patient's leg length in our clinic if I want to be absolutely sure. From the patient's anterior superior iliac spine (or ASIS) to the medial malleolus.

There are also "short cuts" we use without using measuring tapes if we're rushed for time. Getting the patient to bridge (or lift their buttocks) and straighten the legs. Just tricks of our trade ....
Get the patient to lift their bottom
Compare leg lengths
Many people will have a "temporary" leg length discrepancy due to overworked hamstrings, standing a lot on one leg or having hips that tilt forward.

See the difference?
Here's a more obvious picture, R hip higher
Problems that may arise from a temporary leg length difference are usually increased load to the muscles and joints working to counteract the imbalance.

Most of the pavements we run on are banked such that when it rains, water doesn't accumulate on the pavement. If you consistently run the same route during your daily training, (because of the sloping pavement) it creates a temporary difference in leg length. The "longer" leg is making more contact and taking slightly more load compared to the "shorter" leg.

If the muscles work too hard (when you increase your running distance or speed), they are not used to the new load, then an injury can happen.

In other cases, leg length discrepancies may be due to a structural problem like scoliosis in their spine. However, many patients that I have treated with scoliosis manage to adapt without any real issues. And that's probably a different post.

Now you know. So don't be too worried when your health care practitioner tells you that you have an "obvious" leg length difference.


Sabharwal S and Kumar A (2008). Methods For Assessing Leg Length Discrepancy. Clin Orthop Relat Res. 466(12): 2910-2922. DOI: 10.1007/s11999-008-0524-9.