Chondromalacia Patella
What is chondromalacia patella?
Chondromalacia patella refers to softening, roughening or breakdown of the articular cartilage on the underside of the patella (kneecap) — the smooth cartilage surface that normally allows the patella to glide frictionlessly through its groove on the femur during knee movement. When this cartilage is damaged, the normally smooth gliding surface becomes irregular, producing pain, crepitus (a grinding or grating sensation) and inflammation in the patellofemoral joint.
It is graded on a scale of one to four based on severity, from superficial softening of the cartilage surface (grade 1) through partial thickness fissuring and fibrillation (grades 2 and 3) to full thickness cartilage loss exposing the underlying bone (grade 4). Grade 4 chondromalacia represents the end stage of a process that, if it continues, can contribute to patellofemoral osteoarthritis.
It is worth distinguishing chondromalacia from patellofemoral pain syndrome (PFPS). PFPS is a clinical diagnosis based on symptoms — anterior knee pain without necessarily any confirmed cartilage damage. Chondromalacia is a structural finding, confirmed on MRI or arthroscopy, indicating actual cartilage pathology. Many people with PFPS do not have chondromalacia, and some people with mild chondromalacia have no symptoms at all. The two conditions overlap but they are not the same thing.
What causes chondromalacia patella?
The most common cause is abnormal patellar tracking — where the patella doesn't move smoothly through its femoral groove during knee flexion and extension, instead tilting, rotating or shifting laterally in a way that concentrates pressure on specific areas of the cartilage rather than distributing it evenly. Over time this uneven loading causes cartilage breakdown in the areas of highest stress.
The factors that drive abnormal patellar tracking are similar to those in PFPS — weakness of the hip abductors and external rotators allowing femoral internal rotation under the patella, inhibition or weakness of the VMO affecting medial patellar stability, tightness of the lateral retinaculum pulling the patella laterally, and foot pronation increasing tibial internal rotation. A high Q-angle — the angle between the line of pull of the quadriceps and the patellar tendon — is also associated with lateral patellar tracking problems and chondromalacia.
Acute cartilage damage from a direct blow to the kneecap or a patellar dislocation can also cause chondromalacia independent of tracking problems. In these cases the damage is traumatic rather than degenerative.
What are the symptoms?
The classic symptom is aching pain at the front of the knee, behind or around the kneecap, that worsens with activities loading the patellofemoral joint — squatting, kneeling, going up and down stairs, prolonged sitting with the knee bent, and running or jumping. A grating or grinding sensation — crepitus — with knee movement is common and can be felt or heard. Swelling within the joint may occur with more significant chondral damage or following aggravating activity.
The pain of chondromalacia is often poorly localised and diffuse — patients frequently describe it as being "under" or "behind" the kneecap rather than at a specific point — which distinguishes it from patellar tendinopathy where the pain is more precisely located at the tendon.
How is it diagnosed?
Chondromalacia is confirmed on imaging — MRI is the most sensitive non-invasive method for assessing patellar cartilage, and can identify changes in cartilage signal, surface irregularity and subchondral bone changes. Arthroscopy, while more invasive, allows direct visualisation and grading of the cartilage and is sometimes performed diagnostically alongside therapeutic interventions such as chondroplasty (smoothing of irregular cartilage surfaces).
Clinical assessment by a physiotherapist will assess patellar tracking, mobility, and the strength of the surrounding musculature, and can identify contributing mechanical factors even before imaging is available.
How can physiotherapy help?
Physiotherapy cannot regenerate damaged cartilage — once cartilage is lost it does not fully recover. What physiotherapy can do is address the biomechanical factors driving the abnormal loading that caused the damage, reduce pain and inflammation, and slow or halt the progression of cartilage breakdown. For many patients, this is sufficient to return them to comfortable, active function.
The approach mirrors that for PFPS in its mechanical components — hip strengthening, VMO retraining, patellar taping, and movement pattern correction — but load management is even more important in chondromalacia given that the cartilage surface is already compromised and more vulnerable to further damage from excessive or incorrectly distributed load. High-impact activity, deep squatting and prolonged stair climbing may need to be significantly modified or temporarily avoided while symptoms are active and tissue quality is being addressed.
Real time ultrasound assists in retraining VMO activation where quadriceps inhibition is affecting patellar tracking. Clinical Pilates is a particularly valuable tool — the ability to load the lower limb in controlled positions with precise adjustment of knee flexion angle and load allows meaningful strengthening without provoking the patellofemoral compression that worsens symptoms.
For patients with grade 3 or 4 chondromalacia where conservative management has not been sufficient, surgical options including chondroplasty, microfracture or cartilage grafting procedures may be discussed with an orthopaedic surgeon. Physiotherapy plays an important pre and post-operative role in these cases.
Our physiotherapists Eliane Machado, Emma Cameron and Bethany Kippen all have experience in patellofemoral conditions and knee rehabilitation. Eliane's doctoral research specifically in patellofemoral pain and biomechanics is directly relevant to the management of chondromalacia patella. All are members of the Australian Physiotherapy Association.
To book or find out more, call us on 07 3706 3407 or book online below. We see patients from across Brisbane's southside including Tarragindi, Coorparoo, Holland Park, Greenslopes and Mt Gravatt.
Chondromalacia patella refers to softening, roughening or breakdown of the articular cartilage on the underside of the patella (kneecap) — the smooth cartilage surface that normally allows the patella to glide frictionlessly through its groove on the femur during knee movement. When this cartilage is damaged, the normally smooth gliding surface becomes irregular, producing pain, crepitus (a grinding or grating sensation) and inflammation in the patellofemoral joint.
It is graded on a scale of one to four based on severity, from superficial softening of the cartilage surface (grade 1) through partial thickness fissuring and fibrillation (grades 2 and 3) to full thickness cartilage loss exposing the underlying bone (grade 4). Grade 4 chondromalacia represents the end stage of a process that, if it continues, can contribute to patellofemoral osteoarthritis.
It is worth distinguishing chondromalacia from patellofemoral pain syndrome (PFPS). PFPS is a clinical diagnosis based on symptoms — anterior knee pain without necessarily any confirmed cartilage damage. Chondromalacia is a structural finding, confirmed on MRI or arthroscopy, indicating actual cartilage pathology. Many people with PFPS do not have chondromalacia, and some people with mild chondromalacia have no symptoms at all. The two conditions overlap but they are not the same thing.
What causes chondromalacia patella?
The most common cause is abnormal patellar tracking — where the patella doesn't move smoothly through its femoral groove during knee flexion and extension, instead tilting, rotating or shifting laterally in a way that concentrates pressure on specific areas of the cartilage rather than distributing it evenly. Over time this uneven loading causes cartilage breakdown in the areas of highest stress.
The factors that drive abnormal patellar tracking are similar to those in PFPS — weakness of the hip abductors and external rotators allowing femoral internal rotation under the patella, inhibition or weakness of the VMO affecting medial patellar stability, tightness of the lateral retinaculum pulling the patella laterally, and foot pronation increasing tibial internal rotation. A high Q-angle — the angle between the line of pull of the quadriceps and the patellar tendon — is also associated with lateral patellar tracking problems and chondromalacia.
Acute cartilage damage from a direct blow to the kneecap or a patellar dislocation can also cause chondromalacia independent of tracking problems. In these cases the damage is traumatic rather than degenerative.
What are the symptoms?
The classic symptom is aching pain at the front of the knee, behind or around the kneecap, that worsens with activities loading the patellofemoral joint — squatting, kneeling, going up and down stairs, prolonged sitting with the knee bent, and running or jumping. A grating or grinding sensation — crepitus — with knee movement is common and can be felt or heard. Swelling within the joint may occur with more significant chondral damage or following aggravating activity.
The pain of chondromalacia is often poorly localised and diffuse — patients frequently describe it as being "under" or "behind" the kneecap rather than at a specific point — which distinguishes it from patellar tendinopathy where the pain is more precisely located at the tendon.
How is it diagnosed?
Chondromalacia is confirmed on imaging — MRI is the most sensitive non-invasive method for assessing patellar cartilage, and can identify changes in cartilage signal, surface irregularity and subchondral bone changes. Arthroscopy, while more invasive, allows direct visualisation and grading of the cartilage and is sometimes performed diagnostically alongside therapeutic interventions such as chondroplasty (smoothing of irregular cartilage surfaces).
Clinical assessment by a physiotherapist will assess patellar tracking, mobility, and the strength of the surrounding musculature, and can identify contributing mechanical factors even before imaging is available.
How can physiotherapy help?
Physiotherapy cannot regenerate damaged cartilage — once cartilage is lost it does not fully recover. What physiotherapy can do is address the biomechanical factors driving the abnormal loading that caused the damage, reduce pain and inflammation, and slow or halt the progression of cartilage breakdown. For many patients, this is sufficient to return them to comfortable, active function.
The approach mirrors that for PFPS in its mechanical components — hip strengthening, VMO retraining, patellar taping, and movement pattern correction — but load management is even more important in chondromalacia given that the cartilage surface is already compromised and more vulnerable to further damage from excessive or incorrectly distributed load. High-impact activity, deep squatting and prolonged stair climbing may need to be significantly modified or temporarily avoided while symptoms are active and tissue quality is being addressed.
Real time ultrasound assists in retraining VMO activation where quadriceps inhibition is affecting patellar tracking. Clinical Pilates is a particularly valuable tool — the ability to load the lower limb in controlled positions with precise adjustment of knee flexion angle and load allows meaningful strengthening without provoking the patellofemoral compression that worsens symptoms.
For patients with grade 3 or 4 chondromalacia where conservative management has not been sufficient, surgical options including chondroplasty, microfracture or cartilage grafting procedures may be discussed with an orthopaedic surgeon. Physiotherapy plays an important pre and post-operative role in these cases.
Our physiotherapists Eliane Machado, Emma Cameron and Bethany Kippen all have experience in patellofemoral conditions and knee rehabilitation. Eliane's doctoral research specifically in patellofemoral pain and biomechanics is directly relevant to the management of chondromalacia patella. All are members of the Australian Physiotherapy Association.
To book or find out more, call us on 07 3706 3407 or book online below. We see patients from across Brisbane's southside including Tarragindi, Coorparoo, Holland Park, Greenslopes and Mt Gravatt.
