Knee Chondral Tears & Chondromalacia Patellae: What You Need To Know

Knee pain is one of the most common musculoskeletal complaints seen in physiotherapy. Two conditions frequently discussed - and often misunderstood - are chondral tears and chondromalacia patellae. While both involve the cartilage of the knee, they can present very differently and require an individualised rehabilitation approach.

Historically, cartilage injuries were viewed as a largely irreversible problem that inevitably progressed toward arthritis. However, modern research has shifted the focus toward improving load tolerance, movement quality, strength, and symptom management rather than relying solely on imaging findings.

Importantly, many people with cartilage changes on MRI remain highly functional and pain-free, while others with relatively minor imaging findings can experience significant pain.

What Is Articular Cartilage?

Articular cartilage is the smooth, white tissue that covers the ends of bones inside joints. In the knee, cartilage helps:

• Reduce friction

• Absorb force

• Distribute load

• Allow smooth movement

Unlike muscle or tendon tissue, cartilage has a very limited blood supply, which means tissue healing capacity is relatively poor.

When cartilage becomes damaged, irritated, softened, or develops defects, symptoms such as pain, swelling, stiffness, clicking, or reduced tolerance to loading can occur.

What Is a Chondral Tear?

A chondral tear refers to damage or injury to the articular cartilage lining the knee joint.

These injuries may involve:

• Small cartilage fissures

• Partial thickness defects

• Full thickness cartilage lesions

• Loose cartilage flaps

• Associated bone irritation

Chondral injuries can occur in multiple areas of the knee including:

• Patella (kneecap)

• Trochlea (groove underneath the kneecap)

• Femoral condyles (knuckle-like prominences at the bottom (distal) end of the femur (thigh bone))

• Tibial plateau (the flat, top surface of the tibia (shin bone) that forms the lower half of the knee joint)

  

Common Symptoms

Symptoms can vary significantly depending on the size and location of the lesion.

Common presentations include:

• Pain with stairs or squatting

• Swelling after activity

• Clicking or catching

• Pain during prolonged sitting

• Reduced running tolerance

• Stiffness after inactivity

• Pain with jumping or landing

• smaller lesions may be completely asymptomatic.

What Is Chondromalacia Patellae?

Chondromalacia patellae refers to softening, irritation, or degeneration of the cartilage on the underside of the kneecap (patella).

It is commonly associated with:

• Patellofemoral pain

• Increased patellofemoral joint loading

• Muscle weakness

• Altered lower limb mechanics

• Training load errors

Historically, the term was often used interchangeably with patellofemoral pain syndrome. However, modern understanding recognises that cartilage changes alone do not always explain pain. Many people with MRI evidence of chondromalacia have no symptoms at all.

Because of this, clinicians now place greater emphasis on:

• Load management

• Strength deficits

• Movement quality

• Irritability levels

• Functional capacity

rather than focusing purely on “cartilage wear and tear.”

How Do These Injuries Occur?

1.    Acute Trauma

Cartilage injuries can occur following:

• Twisting injuries

• ACL tears

• Patella dislocations

• Falls

• Direct impact injuries

• Sporting collisions

2.    Repetitive Overload

More commonly, chondromalacia and smaller cartilage irritations develop gradually due to repetitive overload.

Contributing factors may include:

• Rapid increases in running or sport volume

• Weak quadriceps or hip muscles

• Poor load management

• Deconditioning

• Reduced ankle mobility

• Biomechanical overload

• Repeated deep knee flexion loading

• High bodyweight loads

This is particularly common in:

• Runners

• Cyclists

• Court sport athletes

• Gym-based athletes

• Occupations involving kneeling or stairs

Latest Evidence

Imaging Does Not Equal Pain

One of the biggest developments in modern knee research is understanding that imaging findings do not always correlate with symptoms.

MRI studies frequently show cartilage changes in asymptomatic individuals.

This means:

• Cartilage findings are common

• Structural changes alone do not determine pain

• Rehabilitation should focus on function and symptom response rather than fear surrounding MRI terminology.

Load Management Is Critical

Modern evidence strongly supports progressive loading rather than complete rest.

Cartilage responds positively to:

• Strength training

• Progressive loading

• Cross-training to keep capacity high

• NOT complete unloading or long-term rest, this may actually reduce tissue capacity over time.

The goal of rehabilitation is therefore to:

• Improve the knee’s tolerance to load

• Gradually restore function

• Reduce symptom irritability

• Improve force absorption capacity

Strength Matters

Quadriceps strength is consistently linked to:

• Reduced pain

• Improved function

• Better patellofemoral joint mechanics

• Improved shock absorption

Hip strength (particularly gluteal musculature) also plays a major role in lower limb control.

Rehabilitation heavily prioritises:

• Quadriceps strength

• Calf strength

• Hip strength

• Single-leg control

• Plyometric capacity

• Deceleration mechanics

Surgery Is Not Always Necessary

Many cartilage injuries can be managed successfully without surgery.

Surgical intervention may be considered when there is:

• Large unstable cartilage flaps

• Mechanical locking

• Persistent swelling

• Failure of structured rehabilitation

• Associated ligament instability

• Significant functional loss

Even after surgery, rehabilitation remains the most important factor influencing outcome.

What Else Could It Be?

·      Patellofemoral Pain Syndrome

o   Often overlaps significantly with chondromalacia.

o   Pain around or behind the kneecap

o   Stairs aggravation

o   Squatting pain

o   Running intolerance

o   Prolonged sitting discomfort

·      Patella Tendinopathy

o   Localised pain at the inferior pole of the patella

o   Jumping pain

o   Tendon tenderness

o   Load-related stiffness

·      Meniscus Injury

o   Joint line pain

o   Locking

o   Catching

o   Twisting aggravation

o   Swelling episodes

·      Fat Pad Irritation

o   Pain below the patella

o   Hyperextension aggravation

o   Swelling around the fat pad

o   Sharp pinching pain

·      Osteoarthritis

o   More common in older populations and may involve:

o   Morning stiffness

o   Reduced joint space

o   Bony changes

o   Activity-related aching

Evidence-Based Rehabilitation Protocol

Rehabilitation should always be individualised depending on:

• Symptom irritability

• Training goals

• Strength deficits

• Functional demands

• Cartilage lesion severity

Phase 1: Settle Symptoms

Goals

• Reduce pain irritability

• Manage swelling

• Restore knee range of motion

• Improve baseline strength tolerance

Key Strategies = Load Modification. This does NOT mean complete rest.

Instead:

• Reduce aggravating loads temporarily

• Modify training volume

• Avoid repeated pain spikes

• Maintain cardiovascular activity where possible

• Early strength work

• Pain-free cross training to keep capacity high

Phase 2: Build Strength & Movement Control

Goals

• Improve force absorption

• Restore single-leg control

• Increase load tolerance

• Movement quality becomes increasingly important during this stage.

Particular focus is placed on:

• Knee control

• Hip stability

• Trunk positioning

• Deceleration mechanics

Phase 3: Energy Storage & Functional Loading

Once baseline strength improves, rehabilitation progresses toward:

• Plyometrics

• Running exposure

• Jumping and landing drills

• Change-of-direction work

• Sport-specific loading

Monitoring:

• Pain response

• Swelling response

• Recovery time

• Next-day symptoms helps guide progression.

Phase 4: Return to Sport or Full Function

Goals include:

• Full training tolerance

• Confidence restoration

• High-speed movement tolerance

• Deceleration capacity

• Sport-specific resilience

Testing may include:

• Single-leg strength testing

• Hop testing

• Running capacity

• Change-of-direction tolerance

• Plyometric control

What About Injections?

Injections may sometimes be considered for symptom management.

Common options include:

• Corticosteroid injections

• Hyaluronic acid injections

• Platelet-rich plasma (PRP)

Current evidence remains mixed.

While some individuals experience temporary symptom relief, injections should generally be viewed as an adjunct rather than a replacement for rehabilitation.

Key Takeaways

• Chondral tears and chondromalacia patellae involve cartilage irritation or damage within the knee.

• Imaging findings do not always correlate with pain levels.

• Many people improve significantly with high-quality rehabilitation.

• Progressive strength and load management are central to recovery.

• Complete rest is rarely beneficial long term.

• Rehabilitation should focus on improving function, movement quality, and load tolerance.

• Surgery is not always necessary and should be considered on an individual basis.

When to see a Physio

Cartilage-related knee pain can be frustrating, particularly because symptoms often fluctuate depending on loading and activity levels. However, modern evidence strongly supports active rehabilitation as the cornerstone of management.

With the right combination of strength training, load management, movement retraining, and progressive return to activity, many individuals can successfully return to running, sport, gym training, and high levels of function.

If you are experiencing persistent knee pain, recurrent swelling, or difficulty returning to activity, an assessment with a physiotherapist can help determine the primary driver of symptoms and guide an appropriate rehabilitation plan.

References

1. Hanna Englund, Guermazi A, Gale D, et al. (2008). Incidental Meniscal Findings on Knee MRI in Middle-Aged and Elderly Persons. New England Journal of Medicine, 359(11), 1108–1115.

2. Kay Crossley, van Middelkoop M, Callaghan MJ, et al. (2016). Patellofemoral pain consensus statement from the 4th International Patellofemoral Pain Research Retreat. British Journal of Sports Medicine, 50(14), 842–850.

3. Michael Rathleff, Rathleff CR, Crossley KM, Barton CJ. (2018). Is hip strength a risk factor for patellofemoral pain? British Journal of Sports Medicine.

4. David Culvenor, Ruhdorfer A, Juhl C, Eckstein F, Øiestad BE. (2019). Knee osteoarthritis following anterior cruciate ligament injury. British Journal of Sports Medicine, 53(18), 1169–1177.

5. Christian Barton, Lack S, Hemmings S, Tufail S, Morrissey D. (2015). The ‘Best Practice Guide to Conservative Management of Patellofemoral Pain’. British Journal of Sports Medicine, 49(14), 923–934.

6. Ewa Roos, Juhl CB. (2012). Osteoarthritis 2012 year in review: rehabilitation and outcomes. Osteoarthritis and Cartilage, 20(12), 1477–1483.

7. Clare Ardern, Glasgow P, Schneiders A, et al. (2016). 2016 Consensus statement on return to sport from the First World Congress in Sports Physical Therapy, Bern. British Journal of Sports Medicine, 50(14), 853–864.

8. Britt Smith, Selfe J, Thacker D, et al. (2018). Incidence and prevalence of patellofemoral pain. British Journal of Sports Medicine.

9. Lars Engebretsen et al. (2010–2023). Various cartilage and knee injury consensus papers from the International Olympic Committee and ESSKA on management of knee cartilage injuries and return to sport.