By Oxford Orthopaedics
By Oxford Orthopaedics
A small pop happens during a warmup, then another occurs as you bend your knee a bit more, and it reacts in a way you don’t usually expect it to. Unlike the aches that follow routine activity, this isn’t the sharp snap or clear-cut strain that comes with a sudden misstep. As the sensation returns with movement or when you bend your knee again, you begin to recognise that it’s coming from deeper within the joint rather than the surrounding tissues, so it naturally stands out more than the usual post activity discomfort or pain.
And as this continues, many begin to notice where the sensation sits within the knee. From here, some describe a firm pressure, while others feel an aching pain in the knee that lingers longer than expected after movements that once felt effortless. Because these sensations don’t behave like normal fatigue, they become harder to interpret as time goes on. This is usually when questions arise about which structure is taking on the strain, and a closer look becomes necessary, since cartilage can be affected in different ways and each injury tends to manifest differently during daily movement.
When cartilage is involved, the sensations you notice can vary because the knee relies on several different cartilage structures, each handling load and movement in its own way. Damage in one area might feel different from changes in another, which is why these injuries are grouped into specific types.
Here are the main categories:
Articular cartilage, the smooth hyaline tissue covering the ends of the knee’s bones, can develop localised areas of damage known as chondral defects. These injuries often follow trauma, repeated overload, or gradual wear and tend to create swelling or a deep aching pain after activity. Lesions may be partial or full thickness, and they can appear as small focal defects or more diffuse surface changes linked with early arthritis. Key features include:
The meniscus is a C shaped fibrocartilage pad that helps cushion the knee and distribute load, and it can tear from twisting, sudden stops, awkward landings, or age-related wear. These tears often cause pain along the joint line, swelling, catching, or locking during movement. Tear patterns vary and influence how the knee behaves during daily activities. Common types include:
Osteochondral injuries occur when damage affects both the articular cartilage and the underlying bone, often from a direct impact or sudden load. These injuries can lead to loose bodies that move within the joint or, in some cases, to osteochondritis dissecans, where a segment of bone and cartilage separates due to reduced blood supply. They tend to create deep, activity related pain and unpredictable mechanical symptoms. Key features include:
The cartilage behind the kneecap can soften or develop surface irregularities, leading to conditions such as chondromalacia patellae (runner’s knee). These changes are common in runners, cyclists, and individuals who frequently climb stairs or squat. Symptoms typically include pain at the front of the knee, discomfort during load bearing movements, and stiffness after sitting with the knee bent. Key features include:
Because different cartilage structures support the knee in their own ways, the symptoms of injury often overlap and can appear during various movements. As mentioned earlier, these sensations tend to surface during bending, twisting, or other load bearing activities, and might begin showing up during routine walking or after periods of rest as the injury progresses. Common symptoms include:
Stiffness or reduced ability to fully bend or straighten the knee
Swelling that appears after activity or returns repeatedly
Clicking, popping, or grinding sensations in the joint
Pain that increases with bending, twisting, stairs, weight bearing, or impact
Catching, locking, or a noticeable snag during movement
A feeling that the knee might give way or struggle with weight
Difficulty with running, squatting, kneeling, or other load heavy activities
Knee cartilage injuries can occur in different ways, and the manner in which the joint moves or absorbs force will determine which area is affected. Some happen in a single moment, while others develop over time when similar movements are repeated without enough time for the joint to recover. These factors relate to how load is placed through the knee, not to how the injury feels or behaves. Common contributors include:
Repetitive stress from running, jumping, squatting, or frequent changes in direction
A sudden twist, direct impact, or awkward landing during sports or daily activities
Biomechanical factors such as malalignment, muscle imbalance, or previous knee injuries
Higher joint load linked with excess body weight or regular high impact exercise
Early arthritis, which can contribute to surface roughening and reduced durability
A clear diagnosis often involves a review by a specialist who can identify which part of the knee is affected and how significant the injury may be. The assessment typically begins with a clinical examination, followed by imaging when more details are needed.
In Singapore, the following methods are commonly used to evaluate cartilage injuries:
Treatment is guided by the type of cartilage involved, the extent of damage, and how the knee responds during daily movement or sport. The following are the treatment options commonly available in Singapore, with care typically planned by a specialist to reduce ongoing joint stress while preserving natural tissue where possible.
For early-stage injuries or milder cartilage changes, non-surgical care is often the starting point. These approaches focus on reducing stress through the knee, improving movement control, and supporting the joint while symptoms are monitored over time.
When non-surgical measures are no longer sufficient, or when imaging identifies a focal cartilage defect, joint preservation surgery would be recommended. These procedures focus on stabilising damaged cartilage or restoring smoother joint surfaces while preserving as much natural tissue as possible. The choice of approach depends on how localised the injury is and how the knee responds to load.
In selected cases, additional techniques are used alongside repair to support healing and improve durability. These are considered on a case-by-case basis and discussed during specialist review.
Beyond the cartilage surface itself, the meniscus plays an important role in how load is distributed across the knee. When meniscus damage contributes to uneven stress or ongoing symptoms, treatment would involve addressing the meniscus to restore cushioning and support overall joint mechanics alongside cartilage care.
In some cases, addressing the cartilage and meniscus alone might be insufficient, particularly when broader mechanical factors influence joint loading. When leg alignment contributes to persistent stress or when degeneration is more advanced, procedures that redistribute force or replace damaged joint surfaces might be considered to improve function.
Knee cartilage injuries can range from mild surface changes to deeper defects that affect how the joint tolerates everyday load. In clinical practice, these differences are often described in grades, reflecting how much of the cartilage surface is involved. What matters more for patients, however, is how the knee behaves over time.
When certain changes begin to appear or persist, a review can help clarify what is happening within the joint and what options are available. Seeking assessment at this stage often allows the widest range of treatment approaches to be considered, with the best chance of preserving joint function and avoiding unnecessary progression. Situations where review is commonly recommended include:
At this point, assessment by a specialist helps determine the extent of cartilage involvement and whether monitoring, non-surgical care, or surgery aimed at preservation of the knee joint offers the most appropriate next step.
Knee cartilage problems are often noticed when stiffness or pain manifests during specific movements, such as bending the knee, the climbing of stairs, or bearing of weight. In some cases, discomfort is felt only after activity or the following day. Because these symptoms don’t always follow a consistent pattern, determining which structure within the knee is involved usually requires assessment by an orthopaedic specialist.
At Oxford Cartilage & Sports Centre, findings are reviewed in detail before any next steps are discussed. Dr Francis Wong explains what has been identified and outlines appropriate options, which might include rehabilitation and load adjustment, targeted non-surgical care, or surgery aimed at preserving the knee joint when appropriate. To speak to our specialist, please contact the clinic to arrange for a consultation.
Movements that repeatedly load the knee can aggravate damaged cartilage. Deep bending, squatting, jumping, sudden direction changes, and frequent stair use place higher stress across cartilage surfaces. If symptoms worsen during or after these activities, reducing load until the knee is assessed helps prevent further irritation.
Cartilage related symptoms tend to persist longer than routine muscle soreness. Ongoing stiffness, swelling after activity, aching that returns with movement, or mechanical sensations such as clicking or catching suggest deeper joint involvement rather than simple fatigue.
Some cartilage injuries develop gradually. Repeated loading from daily movement or sport can exceed the cartilage’s ability to recover over time. Age related changes, alignment differences, previous knee injuries, or increased joint load can all contribute even without a single traumatic event.
The knee contains multiple cartilage structures that handle load differently. Articular cartilage damage often causes deep aching after activity, meniscus tears might lead to joint line pain or catching, and patellar cartilage issues commonly affect the front of the knee during stairs or squatting. Symptoms vary depending on which structure is involved.
Diagnosis usually begins with a clinical examination to assess movement, swelling, and stability. X-rays help evaluate bone alignment and joint spacing, while MRI provides detailed imaging of cartilage surfaces, the meniscus, and surrounding tissues. Arthroscopy might be used in selected cases when direct visual confirmation is required.
Early or mild cartilage changes might improve with non-surgical care such as physiotherapy, activity modification, and load management. However, cartilage has limited healing capacity because it lacks a direct blood supply and relies on joint fluid for nutrition, which restricts how effectively damaged areas can repair under ongoing load. Symptoms that persist or repeatedly return often require targeted treatment based on the type and extent of damage.
Surgery might be recommended when there is a focal cartilage defect, unstable cartilage surface, associated meniscus damage, or when symptoms continue despite appropriate non-surgical care. It’s also considered when cartilage injury limits daily activity or sport and joint preservation strategies are needed.
By Oxford Orthopaedics