Do you struggle with a nagging, deep, aching pain in the front of your knee, with grinding and clicking under your kneecap? Do you also feel like you can predict pain after strenuous activities? These are signs and symptoms linked to Chondromalacia patella. Chondromalacia is defined as the breakdown of a smoothening gel-like structure called cartilage, which covers the surfaces inside your knee joint. Cartilage degeneration can happen in any joint in your body, but when it’s in your kneecap, it is a unique name known as chondromalacia patella. 15-20% of young adults around 25 get it, especially in women. Mainly from repetitive stress on their knees, they are at high risk of wearing out the cartilage underneath their kneecap. This article will discuss the causes, symptoms, and treatment options for Chondromalacia patella, as well as some preventative measures that may help reduce the risk of developing knee pain underneath your patella.

How does cartilage fit into your knee joint?

Muscle Tendon Ligament and Bones

Passive and active structures move and keep your patella in its groove. The kneecap is given its stability through multi-structures that work together to allow the smooth gliding of the patella. The patella is a small bone that slides up and down during knee movement. It sits in a bony groove known as the intercondylar groove. Think of the intercondylar groove as a track, with the kneecap being a sled that slides on the track when bending or straightening your knee. The patella makes contact with different bones during motion.


The cartilage covers the surfaces at the back of your patella, femur, and tibia. This particular type of cartilage lubricates the joint surface to help the patella slide onto the intercondylar groove. When you have chondromalacia patella, there is a degenerative breakdown of this lubricating gel behind your patella. A chronic state of inflammation after activity stimulates a chemical process that progressively destroys the cartilage. This stimulates bone erosion because of bone scraping on bone.

Cells called chondroblasts make up the cell matrix of cartilage. Chondroitin sulfate mixes with proteins in the cartilage, forming a proteoglycan. Together, they form the ground substance of cartilage. The perichondrium is the fibrous sheath around the cartilage that separates it from surrounding structures. The perichondrium is further separated into two layers: the outer fibrous layer, which provides support and protection, and the inner cellular structure, which is responsible for the growth and maintenance of the cartilage.

Three types of cartilage:

  • Hyaline cartilage has a smooth surface, and it is rigid and flexible, allowing the tissues or bones to move freely
  • Fibrous cartilage is the strongest because of its fiber alignment, allowing it to be tough and rigid while still providing support.
  • Elastic cartilage is springy and yellow. Its outer sheath allows it to be flexible and strong.

What does cartilage do and how does it affect the patella?

Cartilage is considered a non-vascular type of connecting tissue, which means it has a low direct blood supply. It is flexible and mainly allows bones to slide over each other. Every place where two surfaces connect makes up a joint. Chondrocytes are scattered and concentrated in the middle of the cartilage, supported by collagen and elastic fibers. Cartilage gets its nutrients via diffusion across the cell borders. Cartilage repair after an injury is very slow because cells cannot reach the injured area.

Articular cartilage provides a smooth, lubricated bony surface for the patella to glide and even balance the force coming through your knee, easing the force coming through your joint. Damage, degeneration, and lesions to the cartilage underneath your kneecap disrupt various knee functions, leading to chronic flare-ups of pain over the front of your knee. 

The Risk factors which lead to the development of Chondromalacia patella:

  • Abnormal gliding of your patella.
  • Boney deformity or mal-alignment of your knee.
  • History of patella dislocations.
  • Trauma or infection to your kneecap.

I have chondromalacia patella … How did it happen?

Cartilage in your knee needs some degree of loading to keep it healthy, but sometimes things go wrong, disrupting normal chemical processes. Chondromalacia patella is one of these disruptions. Repetitive stress forces on your knee joint trigger normal inflammation. This is your body’s way of healing tissue by removing damaged and repairing injured cells. However, it becomes a problem when the knee is now in a constant state of inflammation.

The normal appearance of healthy hyaline cartilage on the deep surface of the patella is bluish-white, smooth, glistening, and resilient. The earliest change in chondromalacia is that the cartilage becomes dull or slightly yellowish-white, soft, and swollen. Characteristically, the site is almost always in the middle, about 2 cm in diameter.

In this constant inflammatory state, the cartilage begins to weaken and become damaged more easily. Following this, it becomes abnormally soft and starts a phase of fissuring. This means that due to its abnormality, it will now begin to develop micro-tears in the cell matrix itself. Repetitive micro-trauma is the leading cause of chondromalacia patella. Micro-trauma is minor scratches, bruises, cuts, lacerations, and tears to the cartilage. The surface becomes uneven over time, leading to an imbalance of forces being translated through your knee.

As the condition progresses, irregular deep cracks and holes develop, and the affected area becomes cartilage flakes anchored to the subchondral bone. Chondromalacia of the patella starts most frequently on the medial facet. This area gradually grows while the cartilage is eroded down to the bare bone at its center. Gradually, the changes extend to the outer edges until the whole patella is affected.

Because cartilage has a poor blood supply, it struggles to keep up with repair. Being unable to fix itself leads to more widespread cartilage destruction, where it begins to erode and irreversibly degenerate. This process is repeated over and over for years until the cartilage is destroyed and the bone scrapes on the bone, causing blisters that shove into the bone core called subchondral cysts.

Stages of Cartilage damage:

The changes of chondromalacia of the patella are classified into four grades. In grade 1, there is softening and swelling of the cartilage; in grade 2, there is fragmentation, slits, and cracks in an area 2 cm or less in diameter; grade 3 is the same as grade 2, but an area more than 2 cm in diameter is involved; and in grade 4, there is erosion of cartilage down to bone.

Causes of chondromalacia patella

A combination of factors often contributes to this condition.

  • Repetitive Trauma: A fracture, dislocation, or repeated patella subluxation causes the hyaline cartilage to wear down faster than usual. However, research indicates that trauma that goes unnoticed or is quickly forgotten may play a bigger role in developing chondromalacia patella.
  • Overuse: Repetitive knee movements, incorrect movement patterns, and technique contribute to increased friction over your kneecap.
  • Muscles: There are imbalances, weakness, and delayed firing patterns in the muscles around your knee, especially the quadriceps.
  • Bone Alignment: The alignment of your hips, knees, and ankles forms the Q-angle. People with a bigger Q-angle usually have “knock knees,” and people with a smaller Q-angle have “bow legs.” Both of these abnormalities result in an abnormal pull on your patella. With time, the wear and tear of the cartilage of your patella makes you more prone to chondromalacia patella.
  • Patella shape: A patella with a flatter shape or knee that is hypermobile can cause chondromalacia.
  • Rheumatoid or osteoarthritis: Arthritis is a systemic condition that degenerates cartilage faster.

Symptoms of chondromalacia patella

Tests that you can do to see if you have a chondromalacia patella

  • Stand on top of a step of at least 30cm.
  • Stand only on your injured side.
  • Lower down slowly so that you touch the floor only with your unaffected side.
  • Push back up without stepping down completely.
  • Repeat the movement 3 times by lowering down and touching the floor.
  • The test is positive for Chondromalacia patella if it brings on your pain while stepping down.
  • Stand comfortably with your legs shoulder-width apart.
  • Start by doing a squat or crouching down low.
  • Then jump up as high as you can. Repeat this jump 5 times within 10 seconds.
  • Repeat the test by jumping only from one leg and landing only on that same leg.
  • The test is positive for Chondromalacia patella if it brings on your pain while jumping or fails to do it in 10 seconds.
  • Kneel on a soft yoga mat or carpet.
  • Firstly, compare the pressure you feel when you put your knees down on the carpet or yoga mat.
  • Sit down until your buttocks are on your feet.
  • Repeat this hunch movement 5 times in 20 seconds.
  • The test is positive for Chondromalacia patella if it brings on your pain or fails to do it in 20 seconds.
  • Sitting upright on a chair or the bed.
  • Straighten your injured knee as far out as you can.
  • As you straighten it, tighten your thigh muscles as much as possible. Repeat this three times in 30 seconds.
  • Once you have it straightened, use the web of your hand to put extra pressure onto the front of your patella.
  • If this causes knee pain or limited range of motion when straightening your knee or with the added pressure, the test is positive for Chondromalacia patella.

How severe is my chondromalacia patella?

Chondromalacia patella is graded into four stages.

Stage 1

The first signs are due to repeated degeneration of the hyaline cartilage under your kneecap, which becomes more spongy and soft. Your patella joint pain depends on how much you exert your knee. The intensity of the pain is still bearable, even after training vigorously, but it is annoying. Noticeable, especially when climbing stairs or long runs. The pain lasts about 5-10 minutes but doesn’t exceed an hour. Stiffness and ‘readiness to move’ becomes noticeable. Standing up after sitting is uncomfortable, and settling takes about 10 steps. The pain is mainly after strenuous training; it’s usually uncomfortable initially, eases off, and worsens afterward.

Stage 2

Stage 2 is confirmed by blisters forming in the cartilage. Blisters push into the bone, making cracks between the cartilage fibers, but the underlying bone stays unaffected.

The pain lingers for longer after activity and starts becoming painful with walking. The discomfort progresses to mild pain in certain positions. Kneeling becomes difficult, or even standing up from a crouched position. The pain is more restricting. Morning stiffness takes longer to disappear. You notice driving and getting out of the car is quite a challenge. Your pain starts limiting your training, and you become hesitant to do specific motions.

Stage 3

Further progression and worsening of the cartilage damage with added subchondral bone cysts, where more than 50 % of the surface area is destroyed, are accompanied by blisters pushing into the gaps and piercing the underlying bone, reaching deeper into the eroded bone.

In this stage, the cartilage under your kneecap is very bad. Your patella joint pain is more constant than before but relieves with rest. The intensity of the pain is very limiting and even stops you from training or exercising. You know you can expect pain from certain activities, like getting out of the car. Standing up after sitting for just a few minutes is painful, and you put your knee in a specific position to avoid the pain. The pain rarely settles. The pain is mainly after light everyday activity. Stiffness is almost constant.  Puffiness and swelling around your kneecap are common.

Stage 4

The last stage of knee joint cartilage damage where more than 50% of the underlying bone surface is destroyed. Complete erosion and degeneration of the cartilage and osteophytes occur on the underlying bone. The patella grinds and scraps over the femoral condyles as you move. The patella and knee joints are constantly painful and more intense. Even anti-inflammatory medications only give short-term relief, and it keep you from doing everyday tasks. The pain does not go away, and spikes of pain are unavoidable. Bending or straightening your knee is limited and painful, even with no load. The swelling around your kneecap is constant, with pain spreading into your thigh and calf.


Diagnosing chondromalacia patella can be challenging because you may experience a variety of symptoms. Our physiotherapists are experts in anatomy, pathology, and movement and can quickly identify the root cause of your knee pain. We have experience working with complex assessments and determining the hierarchy of the structures that take priority to your unique circumstances. A thorough physical knee examination where we stress test all the structures around your knee, including muscles, ligaments, tendons, nerves, and joints. Our practitioners have the skill to pick up any abnormality and grade your injury’s severity. This helps us control the healing environment and limit activities that may worsen it. Our practitioners will attend to the secondary compensation that your body uses to accommodate.

One of the components we’ll test is the knee range of motion. Looking at the available range, quality, and control of motion combined with the patella’s gliding is an essential aspect of diagnosing your Chondromalacia patella. Muscle strength, length, power, and, more importantly, the firing pattern and ensuring the sequence of muscle contraction is correct are also important. Ligament stability is a significant component, so we’ll stress test all the ligaments in your knee. If we suspect your knee classifies as a Stage 3 or 4, we will refer you for X-rays and measure the extent of cartilage erosion.

Chondromalacia patella is common in people between the ages of 15 and 35, especially females. If you are highly active and have a considerable dull ache behind your knee cap, assessing it before it progresses into stage 3, chondromalacia patella is best.


X-rays are still useful in the early stages of the Chondromalacia patella, as imaging provides a baseline to measure the progression over the years. Good quality X-rays even show the stress reactions and force concentration over the bone. There’s no special X-rays needed, the standard AP, Lateral and axial views are helpful to see deformities, integrity of the patella, bone oedema, surface area of fraying or focal defects and subchondral cyst and degree of cartilage erotion. We even measure the position of your patella and the depth of the femoral intercondylar groove.

Your physiotherapist can refer you to get x-rays taken if necessary.

Computerised Tomography

A CT scan is a more detailed image that visualizes any bony abnormalities such as fractures, patella tilt, or trochlear dysplasia. Surface area defect under the patella is clearly visible, and cracks, lesions, and lacerations are seen in more detail. It’s rarely done, and MRI is rather opted for. In the first and second stages, the defect may be difficult to expose the extent of the damage. A CT scan can be used in ongoing pain but is not recommended in favor of an MRI scan.

If you need a CT scan, your physio will refer you.


An MRI remains one of the best tools in diagnosing Chondromalacia patella in borderline stages 2 and 3. It is a must-have in state 4. It allows an in-depth look at the patella, trochlear groove, patella alignment, ligaments, tendons, and, more importantly, cartilage.

Degeneration and secondary bone damage help us diagnose by identifying any space loss and surface loss between the knee cap and underlying bone. Subchondral cysts and bone edema are measured accurately. An MRI is useful when the macroscopic dysfunction is not detectable on X-rays or when there are any early signs of degeneration.

We may refer you to the right specialist if your physiotherapist suspects anything more serious.

Why is the pain not going away?

With Chondromalacia patella, function and capacity are expected to worsen over time. Chondromalacia is the degeneration of the cartilage under your kneecap. Pushing through the pain is one reason patients neglect to seek help. Especially if you continue running, walking long distances, or going to the gym, don’t ignore the early signs and symptoms. We have years of expertise in these types of conditions, so get it assessed before it worsens.

The core function of your patella is disrupted, and the longer abnormal forces go through your knee, the more friction is caused on the joint surface under your kneecap.

Compounded by the poor blood supply, adequate healing is very long and slow. The time cartilage takes to repair damaged areas is long, and it is unable to keep up with the rate of damage. The repetitive micro-trauma to the patella, femoral, and tibial connecting surface stays in a mode of constant inflammation, causing pain under your kneecap.

Overloading the knee while it’s already compromised lowers its capacity to tolerate compression and fore dispersion over the patella. This can accelerate the destruction to the point where everyday activities aggravate it. Rest is also not the solution, as it may even weaken the thigh muscles that stabilize the patella, leading to even more grinding and translation of the patella. We are skilled in dealing with the loading in each phase of healing.

What NOT to do

  • Continuous use of anti-inflammatory medication.

  • Manage the pain through medication alone.

  • Walk, run or gym through the pain.

  • Wear a knee brace continuously without knowing what you’re dealing with.

  • Ignore pain that gets worse over months.

What you SHOULD do

  • Rest as needed.

  • Do safe movements and exercise within limits of your pain.

  • Make an appointment to confirm the diagnosis.

  • Determine how severe the tissue damage is.

  • Finish your treatment and rehabilitation programme for better long-term results.

Making it worse

  • Sitting in crouched position

  • Driving for long hours

  • Squats and lunges

  • Crouching down

  • Running

  • Jumping

  • Climbing stairs

  • Wearing unsupportive shoes

  • Hiking

  • Trail running

  • Kicking a ball

Problems we see when patients come to us with chondromalacia patella

Various complications can arise if you do not get the correct treatment following your Chondromalacia kneecap. We can prevent and mitigate these complications from happening or getting worse.

Waiting too long

The longer you wait, the bigger your chances of causing permanent damage to your kneecap. Treatment must start within the early stage 1 of the chondromalacia patella. We aid the healing process by performing techniques that decrease the pain and swelling. We prescribe gradual progressive exercises to ensure smooth gliding of your patella without causing a flare-up. Don’t avoid treating it. This compensation and adaption can be avoided if treatment starts sooner, making the treatment more complex.

Wearing a brace or knee guard for too long

A knee brace or guard is a helpful tool when treating chondromalacia patella. Usually worn for two days to one week, a brace restricts the kneecap by not allowing too much movement. It also protects the patella, which still requires work. Dependence on the brace is a problem because the compression on the patella crushes the joint surfaces, accelerating the rate of degeneration.


During the initial treatment phase, medication is helpful to manage the inflammatory process of your chondromalacia patella. However, medication alone is not the solution to the problem. Apart from the side effects, medication is a tool to manage pain, not tissue correction. Taking medication to get through it, you must accept that cartilage damage may get worse. As long as there’s recovery time spaced in intervals, but in most cases we’ve treated, medication is used continuously to numb the pain, which gives you a false sense of recovery. We want to wean you off the medication as soon as possible.

Physiotherapy treatment for Chondromalacia patella

We can deliver the best clinically suited program and protocol for your Chondromalacia patella. Our thorough approach provides the necessary guidance, education, and answers to ensure that you can confidently return to the activities that you love.

Apart from severe late-stage 4 chondromalacia patella, a non-surgical treatment program of 12 weeks is crucial for recovery from chondromalacia patella. We use various forms of treatment that focus not only on your knee but also on the surrounding structures, like muscle-firing patterns of the quadriceps, hamstring, calves, and glutes. Supporting ligaments for stability. We can isolate and strengthen these ligaments. Knee joint interactions between every connection of the patella with the femur and tibia.

Treatment comprises of Two main Themes:

Monitoring over months and years determines the rate of cartilage destruction and makes decisions about the intensity of activity that’s safe to do or cut back on. Our goal evolves around preventing the damage from getting worse and slowing down the rate of cartilage erosion.

Treatment focuses on controlling the pain and components of function, getting it back under control, and defining the barriers to capacity. Assessing your daily tasks and functional capacity will guide us in advising you on what to do and avoid.

We use our whole arsenal of treatment techniques for chondromalacia patella. Techniques such as taping or strapping allow the patella to move within its pain-free range by redirecting forces. This taping prevents your patella from sliding into a degenerative zone, which causes further damage. A combination of strengthening, manual therapy, and laser therapy is best suited for the rehabilitation of a Chondromalacia patella.

Phases of rehabilitation

1st Phase: Protection & Establish capacity (Week 0 – 2)

The main focus in the initial phase is to rest and protect the patella. Due to the previous repetitive trauma that the cartilage, patella, and knee joint have sustained, rest and unloading from weight-oriented activities such as running are essential during this phase.

We will determine your capacity limits by guiding you on what’s safe to do and what to avoid to prevent your chondromalacia patella from worsening. This will help you understand what changes are happening in your patella and why. We’ll discuss the short-term milestones, objectives, and expectations. Various strapping techniques are available for pain and swelling. Quadricep, hamstring, and glute muscle isometric exercises are the starting point.

By the end of week 2, you should be able to walk comfortably with about 3/10 pain and able to stand up with ease.

2nd Phase: Range (Week 2 – 4)

Now, we focus on increasing the load on the patella-femoral joint and regaining a pain-free range of motion in the knee joint. the quality of movement is important as we aim to promote flexion and extension in an unloaded position while avoiding a flare-up of cartilage inflammation. Our practitioners also use modalities such as laser therapy, dry needling, and strapping. This is to aid optimal healing in your chondromalacia patella.

To progress to the next phase, you should be able to walk 10 stairs comfortably and sit in a crouch and lunge position.

3rd Phase: Load (Week 4 – 6)

Increasing the amount of stress load through the knee joint and patella is essential in this phase. Exercises will be progressed to mimic the effect of weighted activities and continue a progressive loading program. Starting with simple simple step-down within your pain-free range, as you get stronger – we progress. We will regulate the amount of load through our knees.

By the end of this phase, you should be able to walk 5 flights of stairs without pain and stand endurance for about 30 minutes without pain.

4th Phase: Strength (Week 6 – 8)

During this phase of treatment, it becomes more challenging and intensive as your patella is now stable and pain-free. This allows more stresses and loading in the patella-femoral joint, which is still within your boundaries. Progression of exercises for more targeted forces going through the patella. Strength exercises will progress into more challenging movements like squats, knee extensions, and hamstring curls. Our hands-on treatments continue to be used in this phase to mitigate any flare-ups mainly.

Able to perform 10 pain-free squats, with 30 lunges and 10 countermovement jumps.

5th Phase: Reintegration (Week 8 – 10)

By phase 5, you should be able to perform and re-integrate into your everyday activities easily and confidently. We will look at the reintegration in this Phase, building into your final Phase. This means that we have completed your foundation and progressions. The main focus in this Phase is to mimic movements and stresses that you must be able to do to keep yourself safe. Loading your patella with these types of stresses so that it will not surprise your patella when you return to training.

Our treatment program for Chondromalacia patella focuses on explosive and agility movements, such as agility drills that build up speed, single-leg hopping, rotational hopping while landing on one leg, and dynamic strengthening exercises such as a bear crawl, squat jumps, and box jumps. These stresses will set you up for your final Phase and ensure no stone is left unturned. Once cleared, you will have the confidence and guidance to know exactly how strong and stable your patella is.

To progress to the next Phase, you should be able to skip for 5 minutes and jog at 70% without pain.

6th Phase: Clearance (Week 10 – 12)

By stressing, reassessing, and continuing the end-stage treatment of your chondromalacia patella, we must ensure that the injured structure is now stronger, stable, and able to withstand forces. The final two weeks are for fine-tuning. This allows us to give you the all-clear and consider the Chondromalacia patella under control. However, long-term monitoring will still be needed every year to assess the rate of degeneration. You should be able to walk, jog, sprint, jump, land, and without pain for medical clearance. You should know how to manage your patella in case of a flare-up.

Healing time

A non-surgical treatment for Chondromalacia patella recovery requires a 12-week treatment program to control the pathology and halt cartilage degeneration. The stage of degeneration, commitment to the program, and patience determine the success of rehabilitation. A clinically based and objectively measured program of 4 months shows the best results for long-term recovery.

If surgery is considered after the non-surgical approach has failed, arthroscopy is the best option. Healing time after your surgery can be between 16 – 21 weeks. Surgery for chondromalacia patella is a lengthy recovery, as the surgery only corrects the structural dysfunction. The tissue adaption and optimal safe loading muscle strengthening take much longer if the damage to the cartilage is so severe.

You will need to see your physiotherapist weekly or, in more severe cases, twice a week. After two months, your intervals between sessions are spaced at once a week.

Other forms of treatment

  • Medication: A doctor can prescribe non-steroidal anti-inflammatory drugs (NSAIDs) or cortisone as a form of treatment. Unfortunately, the relief will be temporary if you don’t treat mechanical problems.
  • Stem Cell Therapy: Mesenchymal Stem Cell (MSc) treatment has gained momentum over the last two decades. Research has advocated for it to be safe, effective, and promising in treating chondromalalcia patella. However, it is still an experimental and expensive form of treatment.
  • Knee braces: A brace or knee guard is used in the first phase of recovery, but it must be limited to two weeks. It provides stability and helps decrease strain on the knee joint.
  • Foot orthoses: Insoles and orthoses distribute your weight evenly based on your foot arch and structure. This can help ease your symptoms and alignment.

Is surgery an option?

Surgery for a Chondromalacia patella is the last resort once a non-surgical rehabilitation approach has failed. The type of surgery depends on your age, level of activity, and your history of trauma to your knee.

In addition, there are a few indicators that you should “qualify” for before having surgery for Chondromalacia patella. These are:

  • Failed non-surgical approach.
  • Extensive cartilage and joint space loss in stages 3 & 4.
  • Low trochlear depth refers to the track on which your patella slides. Research has shown a low trochlear depth and the angle at which your patella tilts when moving.
  • Boney changes in severe Stages 3 and 4.
  • Displaced fractures.
  • Excessive patella mal-tracking.

The types of surges that can be done once all the factors above are checked include:

  • Patellectomy – Can be a partial or total. It is only recommended for patients with excellent quadriceps muscle strength.
  • Tibial Tuberosity surgeries—In severe stage 3 or 4 cases, your leg bones will be affected. This surgery aims to restore joint function in your knee.
  • Arthroscopy is the most common type of surgery for a Chondromalacia patella. The aim is to smooth out any rough parts of cartilage in your knee and is used in stages 2, 3, and 4. Research has shown that only 10% of patients with chondromalacia patella need this type of surgery.

These surgeries aim to correct structural problems in the knee joint, and rehabilitation focuses on adapting to this new change and limiting complications. We are experts at navigating the rehabilitation following a patella surgery. Allow us to guide you through this process while getting you back to your best as fast as possible.

What else could it be?

  • Osteoarthritis is a degenerative disease that affects joints. It is similar to chondromalacia patella but typically affects the tibiofemoral joint rather than just the patellofemoral joint.
  • Patella Subluxation – Hypermobility or an injury that causes the patella to move/dislocate in and out of its groove. Repetitive subluxation leads to an unstable knee joint.
  • Hoffa’s fat pad syndrome is inflammation of the fat pad that sits underneath and behind the knee cap. It is caused by repetitive trauma or injury and causes many of the same symptoms as the chondromalacia patella.
  • Runners Knee
  • Knee bursitis
  • Knee tendinitis
  • Knee ligament Tear

Also known as

  • Runner’s Knee
  • Anterior knee syndrome
  • Patella-femoral pain syndrome
  • Knee-cap pain