Doctor On Call (DOC): Dr Sean Leo – Common Sports Injuries (Part 2)

DOC common sports injuries Q&A

Doctor On Call, or DOC for short, is a brand new series brought to you by Medical Channel Asia.  This series aims to bring doctors and specialists from various fields to give you an introduction to common health and medical topics that you and the Asian population are interested in. In our 1st DOC, held on 28 May (Friday), from 8pm to 9pm (GMT+8), we have Dr Sean Leo, orthopaedic surgeon from Orthokinetics, to talk to us about Common Sports Injuries.

For Part 1 of the forum, we have Dr Sean Leo give us a short presentation on some of the pointers regarding common sports injuries. In Part 2, Dr Sean Leo answers some of the questions posted LIVE by our audience. Read below to find out what are some common questions regarding sports injuries that the audience have asked, you may find some relevant to yourself as well!

Question and Answer

Q1: How can we reduce knee pain especially in the knee cap when cycling or jogging?

Dr Sean: Anterior knee pain (where the knee cap is at) can be a result of different things. It can be due to cartilage injury, or the muscles not as strong. This can lead to the knee caps not moving in a proper manner. To avoid making this situation worse, best to find out why you are having that pain. A GP should be able to do a primary assessment of the knee. If it is structural issues or more serious, he or she may likely refer to an orthopaedic surgeon.

What you can do is to rest the area, treat it with painkillers. You have already over-strained it, and there may be some inflammation going on. Pain-killers and rest may be sufficient to control it. For some conditions, you may see a physiotherapist to correct the posture (e.g. jumping and bending in the right manner). They can also target areas of muscles that are weak. If it is a structural problem (e.g. cartilage injury), you would likely require the help of an orthopaedic surgeon to address it.

Q2: Is meniscus posterior horn tear repairable?

Dr Sean: Yes it is. In fact, posterior horn or root tear have historically been difficult to repair due to the small space. But the meniscus is an interesting structure: it is anchored on the front (i.e. horns) and back (i.e. roots) ends. When these areas get cut off, the whole meniscus is unable to function properly as it displaces easily with weight. The repair usually involves putting a structure (i.e. a string) through the part. If it is near the roots or right at the end of the meniscus, we have to drill a hole through the bone and anchor the torn bit into the bone.

Today, there are a various new instruments that allow us to do this fairly easily and with minimal injury to the cartilage surrounding the area. Hence, we do see more people with root injuries have them repaired.

Q3: What can you recommend for flat foot runners? I tried using insoles but it didn’t really help.

Dr Sean: Flat feet is a fairly common occurrence. There are 2 kinds:

  • Rigid flat foot – your foot does not change in shape even when you tip-top. Usually a structural issue with the bones. Some of the bones may have fused with each other, hence they are unable to move. This is the more severe type of flat foot, which will require surgery to be done to treat it.
  • Flexible flat foot – more common type. Could sometimes be due to the ligaments or muscles being more lax.

Using insoles certainly help to put them in correct positions. However, they are not the only thing. You likely will need to strengthen the muscles, and your physiotherapist may be able to help to strengthen the right muscles (e.g. tibialis posterior tendon – important in holding up the medial arch). You can also see if certain shoes are able to help. People with flat feet tend to pronate, where the medial arch are pressed down. Certain shoes can help with over-pronation, and help in terms of the symptoms.

Q4: Osteoarthritis (OA): Are there any supplements that you can recommend for knee pain?

Dr Sean: Supplements are not considered medications. The standard for making the claims for supplements are not as stringent as for medications. Medications require robust studies and results to prove their claims. For supplements, the may have multiple claims of what they can do. There are differing results for different people. It is difficult to recommend supplements because the effect may not be as predictable and we cannot quantify the results.

For osteoarthritis, some common supplements that people use include omega 3 fish oils, glucosamine, and collagen. Some of my patients take this with very good effect and I encourage them to continue. However I also tell some patients who are starting to take it, I will tell them that if it is not helping them after 3 months or so, they can stop taking it.

Q5: Is past ACL reconstruction injury a cause of OA for old age?

Dr Sean: Another way of seeing is that, a previous ACL reconstruction does NOT prevent OA. Even if you had injured your knee and we have replaced the ACL, we cannot restore the function completely to what you were born with. Also, as the knee is injured, we may not only injure the ACL but also other parts of the knee. These things may have a longer term effect (months or years later). An example is bone bruise, where a bone knock against another bone causing injury. This is fairly common in patients with ACL injuries. In fact, the ‘pop’ sound that we hear during an ACL injury is due to the bone hitting against another bone, and not due to the ACL tear.

These may also result in cartilage injury over longer period of time which may not be present at the point of ACL reconstruction surgery. Hence, if we compared a knee with ACL reconstruction done and another knee without any injuries before, it would still tend to degenerate and get OA earlier.

Q6: I had an ACL reconstruction last April and was cleared to play competitive ice hockey after 6 months. Should I be concerned about the other tears shown on the MRI: partial MCL tear and menicocapsular separation?

Dr Sean: A partial MCL tear tends to be quite predictable. MCL is pretty vascular, and so it tends to be able to heal better, if it is not a complete, 3rd degree tear. Even if it is, it still is able to heal and be able to get back to activity, although not to 100% (will have some laxity remaining behind). Hence, I feel the MCL injury is not too worrying.

The meniscocapsular separation depends on the size. Usually a small one at the back of the knee can heal better and stabilise as it is more vascular (more blood supply). If it is a very large separation, it is more predictable if it is repaired.

If the surgeon and physiotherapist have cleared to play sports, I think you should be okay to do that.

Q7: I hear a crackle sound on both knees but it’s painless when they bend. Should I be concerned?

Dr Sean: Sometimes these clicks and pops happen, just like cracking of the knuckles. As long as it is not causing discomfort, it may be fairly normal to hear these clicks and pops. It can also be the result of a tendon or something else going over a bony prominence, which can cause the click and pop as well.

The main thing I would want to access is whether you feel any jamming of your knees. If you feel that when you are walking the clicks are associated with you being unable to straighten your legs or something getting stuck in the knees, it would be more worrying. Swelling of the knee as a result of this crackle could also mean that the cartilage is not smooth, and there may be cartilage injury.

It is not taken by itself. Rather, it is taken together with a whole other bunch of symptoms. Usually the doctor will start asking more questions with regards to them.

Q8: What do you think about PRP (platelet-rich plasma) injections? How effective is this and do you need to frequently repeat this?

Dr Sean: This is a new form of treatment, which I think over the last 7 to 10 years have became more popular. PRP involves drawing out blood and spinning it down to concentrate the platelets. It is then injected back to the injured area. Platelets contain growth factors, which helps to concentrate at the injured area. These growth factors are supposed to stimulate healing.

It has shown to have good results in certain indications: for e.g., in Achilles tendon tear which is surgically repaired, putting PRP has been shown to help repair that. For things like acute muscle tears or ligament and tendons injuries where no injuries are performed, PRP injections to the area have been shown to improve those symptoms as well.

Singapore’s Ministry of Health has approved for these 2 indications. Beyond these, for e.g. injecting to the joints and many other indications, are considered off-label. This means that the theory behind it is sound, but we do not have enough evidence for it to be used widely. For these off-label uses, we need to practice more caution and patients need to understand what is being done.

One concern is that in the market there is not a standardised version of the PRP (i.e. how much platelets within the injection) for the different preparations available. You can end up with a different amount of platelets between the injections. The amount being drawn up can also be different. Much of these are not being standardised yet, hence it is difficult to compare the studies that were conducted and conclude the use of PRP.

It is relatively safe, as we are injecting what we are drawing out of your body back into yourself. Hence, that could be the reason many people find it acceptable to doing it. There are also studies which show that injecting PRP into the knee does help with symptoms.

Q9: What are the criteria that doctors look into for allograft/ autograft when there is ruptured ACL?

Dr Sean: ACL reconstruction with allograft vs autograft. Autograft means using the own body’s graft. Allograft means using another person’s graft. Both are accepted treatments and come with their respective pros and cons.


  • Pros: Fast, no rejections, inexpensive
  • Several studies shown that using autograft has better results than using allograft, in terms of the laxity and re-rupture rates.
  • However, it is to be noted that these findings may not be applicable to everyone. Much of it depends on what kind of activities are being done. If you are not extremely active and are very careful with the knee, the risks would also be very low


  • Offers no donor site morbidity: no parts of your own body is being sacrificed to repair another part of your body. You maintain your own ligaments and grafts as you get them from other people. This can prevent further injury to other parts of the body.
  • You can select the graft of a particular size. If you used your own grafts and harvest your own hamstrings, you are stuck with whichever size that you have. However, if you are using somebody else’s graft, you can inform the particular size that you require in advance. This can benefit people who may be larger in size and usually have requirements for bigger grafts.
  • Revision cases: you want to avoid getting more grafts from yourself, hence allograft is a good alternative.

In general, I find that in my patient pool at least, they do fairly well with both autograft and allograft. I have done revision reconstruction for some of the high demand athletes using allograft, and they are still able to do their work just as well. Hence I believe that is it not such a straightforward answer, it really depends on what you think you are going to do, whether you feel that you want to sacrifice any parts of your body etc.

This needs to be discussed thoroughly with the patients, and I usually take 15 to 20 minutes to discuss the 2 choices. I don’t think there is a right or wrong answer, as long as you believe in the reasons why you are using a particular method.

Q10: Why would a doctor recommend conservative treatment instead of surgery for a 75% meniscus tear for an active basketball player aged 14yo?

Dr Sean: For a meniscus injury, a lot of it depends on where this tear occurs (peripheral vs central). I’m not too sure what 75% tear means? It could involve 75% of the area of the meniscus, or that it is not a full tear of the meniscus (only tear through 75% of the meniscus tissue). Sometimes a partial tear at the periphery can scar and heal by itself and not continue to tear through.

A lot of it will have to depend on what the MRI shows. Without looking at the MRI, it is difficult to comment. If it is an unstable tear (e.g. the meniscus flips in and out), it will be an indication for a surgery. However for a 75% tear, a lot of it depends on what the definition of it means.

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