Printed From:

Dealing with Knee Problems

Medical Director
The Orthopaedic Centre


Dr David Su, Medical Director at The Orthopaedic Centre, shares the common causes of chronic knee pain and other knee problems like knee osteoarthritis and Anterior cruciate ligament (ACL) tears.

Chronic knee pain for people below 45 is commonly caused by overdoing and overuse from sports. As for those above 45, the common cause is age-related wear and tear leading to degenerative knee conditions. Three common knee pain problems are Patellofemoral Pain Syndrome (runner’s knee), knee osteoarthritis and knee ligament and cartilage injuries.

Runner’s knee happens when the kneecap is misaligned and rubs against the lower end of the femur. This is often caused by repetitive stress on the knees due to an excessive running or cycling routine. Dr David Su recommended that runners incorporate cross-training in their fitness routine to get a good mix of load on joints and muscles. Some supplements can help to stimulate the formation and repair of the cartilage or keep it from deteriorating.

Knee osteoarthritis, which is the wearing away of the knee cartilage, is the most common form of knee arthritis. There is no cure for this degenerative disease but there are ways to decelerate the cartilage erosion. Shedding 5kg of weight, especially for those who are overweight, can reduce knee pain by 50%. Knee joint injections like hyaluronic acid and platelet rich plasma (PRP) therapy are common temporary measures as well.

ACL tear is the most common ligament injury, especially for soccer players. Physical therapy is often used to restore the knee. However, orthopaedic specialists may advise for ACL reconstruction in the case of complete ACL tears.

DR Kannan
Senior Consultant
Centre for Foot and Ankle Surgery, Singapore

Article 3: Heel pain

Q: My 42 yr old aunt does a lot of running. She has heel pain problem, the pain goes where the Achilles tendon attaches to the heel bones, which interfere with her normal activities, particularly when she exercises. What are the causes factors? What can she do?

She most likely has Achilles tendon inflammation. There are two types of Achilles tendinosis (inflammation of the tendon), based upon which part of the tendon is inflamed- insertional tendinosis and non-insertional.

Pain occurring in the area where the Achilles tendon attaches to the heel bone is known as insertional Achilles tendinitis involving the lower portion of the tendon. This type of Achilles tendinosis is more common in the middle to older age group. A small group of patients may also have associated plantar heel pain (pain on the sole of the heel) due to plantar fasciitis (inflammation of the plantar fascia).

In non-insertional Achilles tendinitis, fibers in the middle portion of the tendon have begun to degenerate. Tendinitis of the middle portion of the tendon more commonly affects younger people.

Bone spurs (extra bone growth) often form with insertional Achilles tendinosis as a response to repetitive stress to the tendon. The tendinosis is typically not related to a specific injury and is a chronic degenerative condition. The bone spur (extra bone growth) where the Achilles tendon attaches to the heel bone can rub against the tendon and cause pain. Some patients experience pain and swelling that is present all the time and it gets worse throughout the day with activity.

In most cases, nonsurgical treatment options will provide pain relief, although it may take a few months for symptoms to completely subside. A structured physiotherapy program helps to condition and strengthen the Achilles tendon.

Surgery should be considered to relieve Achilles tendinosis only if the pain does not improve and it becomes difficult to wear shoes or preform simple day to day activities. It is best to discuss the options with your Orthopedic specialist. The specific type of surgery depends on the location of the tendinitis, amount of bone spurs and the amount of damage to the tendon. The goal of this operation is to remove any excessive bone spurs and repair the damaged part of the Achilles tendon. There are several techniques ranging from keyhole surgery to mini-open surgery for insertional Achilles tendinosis.

Heel pain 

Visual adapted from: Last assessed on 20.3.2018

Dr Tan Chyn Hong
Shoulder Knee Elbow
The Orthopaedic Centre
TMBBS (Singapore), MRCS (Edinburgh),
MMED (Ortho), FRCS (Edinburgh)

Article 2:

Seeking treatment early may prevent need for replacements

I always observe how patients with knee pain walk into my consultation room. From that, I can tell which leg is hurting, and how bad it is hurting .

After all, knee pain is one of the most common symptoms that I see in my practice.

Mr X hobbled into my clinic one day, complaining of pain in both knees. He could not play golf, and even walking around a shopping centre with his wife was painful.

He had tried medication (painkillers, supplements, traditional Chinese medicine), medicated plasters, gels, walking aids, physiotherapy, lubricant injections and even had special shoes designed to shift the stress away from the knees.

He had read up extensively about the surgical options available and he wanted my opinion.

After looking at his X-ray scans, which showed severe osteoarthritis, and considering his age of 69, I recommended the most reliable operation for someone in his situation: A total knee replacement.

He then asked a question that I had heard many times before.

Was there any way to preserve his knee and avoid replacing it with metal and plastic?

My answer was no, not in his case - his arthritis was too advanced.

But I have wondered if I could have preserved his knees had he come to see me years earlier.


Knee preservation surgery is a broad concept that uses minimally invasive keyhole techniques (arthroscopy) to preserve the vital components of the knee.

Knee arthritis occurs when there is cartilage damage, which causes pain and stiffness. Vital components of the knee that contribute to its longevity are the meniscus, cartilage and ligaments.

The meniscus is a crescent-shaped structure made of cartilage. It absorbs shock and stabilises the knee. Forty years ago, surgeons routinely removed the entire meniscus when it was torn.

We now know that removing the whole meniscus is a bad idea. Without it, the knee will almost always develop arthritis .

There is now a big push to repair a meniscal tear and even if you cannot repair it, only the torn potion should be removed.

The cartilage is the white shiny layer covering the ends of the bones. It has lubricating and shock-absorbing qualities. Once you damage it, however, it has limited potential of healing itself.

But we know that cartilage damage in the knee should be treated early. By the time the damage is widespread, there is little doctors can do to regenerate the cartilage.

The patient may have no choice but to undergo a knee replacement with metal and plastic components.

Mr Y, 49, a university lecturer, was fortunate. He sought help early and managed to preserve his knees.

An avid basketball player, he started to experience pain in both knees after a game. It worsened to a point where he could not stand in front of his class for more than 15 minutes.

Magnetic resonance imaging scans showed cartilage damage, as well as "loose bodies" in his knees - little pieces of bone and cartilage that form during the degeneration process. These free-floating objects occasionally jam up the knee, causing a sudden locking sensation.

It is like having a pebble in your shoe when you are walking.

The loose bodies accelerate cartilage damage, grinding away the cartilage when the knee moves.

The advantage of keyhole surgery is that even if both knees are operated on at the same time, the patient can often walk out of the hospital the next day.

Mr Y eventually underwent keyhole cartilage regeneration and removal of loose bodies in both knees. He is now able to stand and teach for an hour.

More importantly, he started playing "old man basketball". He described it as more passing, less running and jumping, and playing with people his own age.

If he continues to take care of his knees and modify his activities to avoid further wear and tear, he might not require a knee replacement at all.

Consultant Orthopaedic Surgeon
MBBS (London), MRCS (Edin),
M.Med (Orth), FRCS (Orth & Trauma)



Osteoarthritis of the knee is the most common disease of the joint. The elderly are most commonly affected.1 Arthritis of the knee causes pain, swelling, stiffness and deformity.2,3 This results in limitation of daily activities such as walking or climbing stairs.3 Initial treatment usually includes the use of medications, rest and physiotherapy.2,4 Adjuncts such as a walking stick or knee brace can also be used.5

Intra-articular injections to the knee are very useful.5 Depending on the condition during assessment, either a special gel consisting of hyaluronic acid or a combination of a local anaesthetic and steroid can be used.5,6 There is promising data from recent studies that PRP (platelet-rich plasma) injections are beneficial. PRP is a special preparation drawn from the patient's blood, which is high in concentration of growth factor proteins. These proteins aid in healing of injuries and tissue regeneration.7

Surgery to the knee may be recommended if conservative treatment does not provide sufficient improvement. Surgery is also an alternative to a more long-term solution.8,9 Joint replacement surgery is a safe and effective procedure to relieve knee pain, correct deformity and restore function to the diseased knee.9

Knee replacement surgery was first performed in 1968. Knee replacement surgery is currently one of the most successful procedures in all of medicine. More than 90% of patients who have undergone knee replacement surgery will experience dramatic improvement in pain and ability to perform common daily activities.10

Depending on the severity of the arthritis as well as the age of the patient, various state of the art modalities can be employed to ensure a smooth and uneventful recovery from surgery.11

Minimally invasive knee surgery was very much in vogue about 10–15 years ago. MIS reduces soft tissue trauma and blood loss allowing for a quicker recovery. This concept has evolved over the years on using advanced surgical techniques and instruments, precise soft tissue handling to ensure excellent outcomes in all patient groups.12,13

Computer-aided surgery is where the surgeon uses the computer with special sensors to fine-tune the entire surgery process at every single step. Computer-aided surgery allows for a high level of precision during knee replacement and results in very accurate placement of the prosthetic knee components.14-16 The result: the knee functions better with longer-lasting implants.15 This technique is now successfully combined with MIS techniques for an even better surgical outcome.17

One of the most exciting advances in knee replacement surgery is to use custom made instruments. These "Patient-Specific Instruments" are custom made to the individual's knee anatomy to allow for a high level of precision during surgery. This technique requires the patient to undergo a high definition MRI (Magnetic Resonance Imaging) scan of the affected leg before the customised instruments are produced.18,19

This technique allows the surgeon to achieve precise alignment and positioning of the knee prosthesis, resulting in high functioning outcomes and increased longevity of the implant. This technique can also be performed via a minimally invasive surgical approach.20

A unicompartmental knee replacement is an option for a selected group of patients, where the osteoarthritis is limited to a single part of the knee (unicompartment). The knee is divided into 3 distinct compartments: the medial, the lateral and the patellofemoral compartment. In a unicompartment knee replacement, only the affected part of the knee is replaced, leaving the other compartments as well as the ligaments of the knee intact.21,22


  • Smaller scar
  • Significantly faster recovery rates
  • Less pain after surgery
  • Less blood loss
  • More natural

The treatment of osteoarthritis of the knee has evolved over the years with multiple treatment modalities available. Patients should consult an orthopaedic surgeon specializing in this condition to ensure an accurate diagnosis and best in class care is provided.


  1. Hunter DJ, Felson DT. Osteoarthritis. BMJ. 2006;332(7542):639–642.
  2. Hunter DJ, Bierma-Zeinstra S. Osteoarthritis. Lancet. 2019;393(10182):1745–1759.
  3. Hunter DJ, et al. The symptoms of OA and the genesis of pain. Rheum Dis Clin North Am. 2008;34(3):623–643.
  4. Bhatia D, et al. Current interventions in the management of knee osteoarthritis. J Pharm Bioallied Sci. 2013;5(1):30–38.
  5. Anandacoomarasamy A and March L. Current evidence for osteoarthritis treatments. Ther Adv Musculoskel Dis. 2010;2(1):17–28.
  6. Jagdish RK, et al. Effectiveness and safety of a combination of intra-articular corticosteroid and local anesthetic in Indian patients with knee osteoarthritis: A pilot study. Austin J Orthopade & Rheumatol. 2018;5(1):1061.
  7. Southworth TM, et al. The use of platelet-rich plasma in symptomatic knee osteoarthritis. J Knee Surg. 2019;32(1):37–45.
  8. Hofstede SN, et al. Designing a strategy to implement optimal conservative treatments in patients with knee or hip osteoarthritis in orthopedic practice: A study protocol of the BART-OP study. Implement Sci. 2014;9:22.
  9. Mayo Clinic. Knee Replacement. Available from: Accessed on 24 April 2020.
  10. OrthoInfo. Total Knee Replacement. Available from: Accessed on 24 April 2020.
  11. Mora JC, et al. Knee osteoarthritis: Pathophysiology and current treatment modalities. J Pain Res. 2018;11:2189–2196.
  12. Picard F, et al. Minimally invasive total knee replacement: Techniques and results. Eur J Orthop Surg Traumatol. 2018;28(5):781–791.
  13. Wright JG. Evidence-based orthopaedics. The Best Answers to Clinical Questions. Elsevier. 2009, pp. 576–577.
  14. Ritacco LE, et al. Computer-Assisted Musculoskeletal Surgery. Springer. 2016, pp. 51–145.
  15. Chotanaphuti T, et al. Comparative study between computer assisted-navigation and conventional technique in minimally invasive surgery total knee arthroplasty, prospective control study. J Med Assoc Thai. 2008;91(9):1382–1388.
  16. Bae DK, et al. Computer assisted navigation in knee arthroplasty. Clin Orthop Surg. 2011;3(4):259–267.
  17. Chandrasekaran S and Molnar RB. Minimally invasive imageless computer-navigated knee surgery: Initial results. J Arthroplasty. 2008;23(3):441–445.
  18. Beal MD, et al. Improving outcomes in total knee arthroplasty—do navigation or customized implants have a role? J Orthop Surg Res. 2016;11:60.
  19. Mattei L, et al. Patient specific instrumentation in total knee arthroplasty: A state of the art. Ann Transl Med. 2016;4(7):126.
  20. Ng VY, et al. Improved accuracy of alignment with patient-specific positioning guides compared with manual instrumentation in TKA. Clin Orthop Relat Res. 2012;470(1):99–107.
  21. Jean-Noel AA and Dalury DF. Partial knee arthroplasty. Springer. 2019, p. 9.
  22. Redish MH and Fennema P. Good results with minimally invasive unicompartmental knee resurfacing after 10‑year follow‑up. Eur J Orthop Surg Traumatol. 2018;28(5):959–965.

Senior Consultant
Orthopaedic Surgeon
MBBS (NUS), MMed (Singapore) FRCSEd (Orth), FACS

Subspecialties in Joint Reconstruction,
Sports Orthopaedics, Fracture Surgery


The Knee
The knee joint, the largest and complex joint of the human body, takes an enormous amount of pressure for even simple day-to-day activities. For example, when climbing stairs or running, each knee joint may absorb three times the body weight. This is one reason why the knee joint is prone to experiencing wear-and-tear, called osteoarthritis. This refers to progressive damage of the cartilage, excruciating pain, restricted movement and reduced quality-of-life.

Knee Injuries
Injuries are the other quite common issues that are associated with knee problems. Some of the problems which are associated include conditions such as anterior cruciate ligament (ACL) tears, medial collateral ligament (MCL) tears, meniscus tears, cartilage injuries and patella dislocations. A lot of people, e.g. skilled sportspersons, sustain ACL tears due to activities such as football, basketball and skiing. An ACL tear, in a young patient, is best treated with surgery to reconstruct a new ACL, therefore giving the patient a good knee for the years to come.

Dr Ang Chia Liang is an orthopaedic surgeon with more than 17 years of experience in the field of orthopaedics (please click on the link to know more: Dr Ang Chia Liang | Centurion Orthopaedic Centre). In his clinical practise, he uses the patient’s hamstring tendons to make a new ACL, thus ensuring the best clinical outcome.

A tissue-healing stimulant injection is useful for injuries with delayed healing, which further stimulates healing in injured tissues.

Osteoarthritis Treatment
The treatment methods for early osteoarthritis include medications, self-therapy exercises and viscosupplementation (e.g. Hylan GF-20). In suitable cases, Hylan GF-20 can give effective pain relief that lasts for 12 months or more. Doctors use information from patients’ symptoms, examinations, X-rays and sometimes MRI to determine patients’ suitability for Hylan GF-20.

Glucosamine and collagen can help in reducing pain and maintaining the joint in early stages.

More advanced stages may require bone marrow concentrate injection, arthroscopic surgery to reconstruct cartilage or knee replacement surgery.

Symptoms of Knee Problems
Common symptoms of knee problems include:

  • The occurrence of severe pain on prolonged walking or standing
  • The occurrence of pain, especially, when the person gets up after sitting for a prolonged time
  • Hearing a sound of pop in the knee followed by swelling
  • Giving way or ‘weakness’ of the knee
  • Feeling movement inside the knee

Risk and Prevention
It is risky to ignore persistent pain. For example, many patients who regularly run report that they have had knee pains after running for a short period of time. They may have ignored it as they felt they could still run. However, by ignoring it, the pain can intensify and stop them running, which in turn promts them to consult a doctor. Sometimes, by this stage, the cartilage would have been damaged significantly, requiring a more advanced treatment method such as keyhole surgery. In general, ignoring the persistent pain for a month or longer period of time is dangerous and may lead to more severe injuries. Hence, consulting a doctor in the early stage is effective and highly recommended to prevent significant damage to the knee.


  1. Lim JB, Ang CL, Pang HN. Acetabular prosthetic protrusio after bipolar hemi-arthroplasty of the hip: case report and review of the literature. J Orthop Case Rep. 2016;6(3):28–31.
  2. Zhu M, Ang CL, Yeo SJ, et al. Minimally invasive computer-assisted total knee arthroplasty compared with conventional total knee arthroplasty: A prospective 9-year follow-up. J Arthroplasty. 2016;31(5):1000–4.
  3. Ho SWL, Ang CL, Ding CSL, et al. Necrotizing fasciitis caused by Cryptococcus gattii. Am J Orthop. 2015;44(12):E517–E522.
  4. Ang CL, Yeo SJ. Quality of cementation in conventional versus minimally invasive total knee arthroplasty. J Orthop Surg (Hong Kong). 2016;24(1):7–11.
  5. Teo EY, Ang CL, Sathappan SS. A variant of patellar clunk syndrome after bilateral total knee arthroplasty: clinical manifestations and arthroscopic images. Orthop Surg. 2014;6(4):326–8.
  6. Ang CL, Foo LS. Multiple locations of nerve compression: an unusual cause of persistent lower limb paresthesia. J Foot Ankle Surg. 2014;53(6):763–7.
  7. Ang CL, Fook S, Chia SL, et al. Unconstrained arthroplasty in type II valgus knees: posterior stabilized or cruciate retaining? Knee Surg Sports Traumatol Arthrosc. 2014;22:666–73.
  8. Ang CL, Phak-Boon Tow B, Fook S, et al. Minimally invasive compared with open lumbar laminotomy: No functional benefits at 6 or 24 months after surgery. Spine J. 2015;15(8):1705–12.
  9. Ang CL, Lim YJ. Recurrent admissions for diabetic foot complications. Malays Orthop J. 2013;7(3):21–6.
  10. Ang CL, Foo LS, Sun S, et al. Positive ProbeTecTM tests in fresh specimens from malignant musculoskeletal tumours: a case series. Orthop Surg. 2013;5(1):29–32.