Articular Cartilage Injuries
Articular cartilage is the tissue covering the ends of bones that allows the joint surfaces to glide almost without friction. Its capacity for self-repair is very limited, because it contains no blood vessels. Cartilage injuries therefore require a different approach from other tissues.
Why Can Cartilage Not Repair Itself?
Cartilage has no blood supply; it is nourished by joint fluid. The bleeding–inflammation–repair sequence seen in other tissues after injury does not operate in cartilage. For that reason damage to the surface does not close on its own and can spread to the surrounding area over time.
Injury can arise from a sudden trauma (a twist, a blow, an impact accompanying a ligament injury) or from repeated loading. A limited, sharply defined defect and widespread wear (osteoarthritis) are different conditions and their treatments differ.
Symptoms
- Deep joint pain whose exact site cannot be pointed to
- Symptoms increased by loading, difficulty with stairs and squatting
- Recurrent swelling and fluid collection in the joint
- Catching or locking — if a fragment of cartilage has become loose within the joint
- A sense of insecurity in the joint and early fatigue
Symptoms can be confused with meniscal tears and ligament injuries; these structures are frequently damaged together.
Diagnosis
- History: mechanism of injury, history of locking and swelling, accompanying ligament injury.
- Examination: range of movement, joint fluid, area of tenderness, alignment and ligament stability.
- X-ray: to assess the joint space, alignment and degree of osteoarthritis.
- MRI: shows the site and depth of the cartilage damage and the state of the bone beneath it.
- Arthroscopy: where needed, the true extent of the damage is assessed by direct vision during surgery.
The grade of the MRI finding does not always match the severity of symptoms; the decision rests on the clinical picture, not on imaging.
Treatment
Non-surgical treatment
In small, asymptomatic defects and where widespread wear is also present, the first approach is not surgical.
- Strengthening the muscles around the joint — this directly affects load distribution
- Weight control
- Activity modification: reducing impact activities, favouring alternatives such as cycling and swimming
- Pain management
- Intra-articular injection treatments in selected cases
Surgical options
Surgery is considered in patients with a limited, sharply defined defect causing mechanical symptoms who have not responded to non-surgical treatment. The method is chosen according to the size, depth and site of the defect and the patient’s age and activity level.
- Removal of a loose cartilage fragment, or fixation back in place where suitable
- Methods that stimulate the bone beneath the cartilage to form repair tissue
- Methods based on cartilage or cartilage-and-bone grafting
- Corrective surgery to shift load to the healthy side where an alignment problem is present
An important point: repair tissue does not have exactly the same properties as natural cartilage. Expectations are therefore discussed openly before surgery. In addition, if an accompanying ligament injury or alignment problem is not corrected, less benefit is expected from the cartilage procedure.
After Surgery
The protection period after cartilage procedures is longer than after many other knee procedures; weight-bearing and range of movement are increased gradually. Adherence to this process is among the factors that most directly affect the outcome. For detail see the Knee Arthroscopy Aftercare Guide.
When Should You Seek Assessment?
- If your joint swells repeatedly
- If you experience catching or locking
- If you have persistent deep joint pain after an injury
- If stairs and squatting restrict your daily life
- If you have had a ligament injury and symptoms persist
When to Seek Medical Help Without Delay
- Redness, warmth and severe pain in the joint together with fever
- Inability to bear any weight on the joint after an injury
- The joint remaining locked and unable to straighten at all
- One-sided pain, swelling and tenderness in the calf
These findings require urgent assessment. Outside office hours, go to the nearest emergency department.
Frequently Asked Questions
Does cartilage regenerate on its own?
The capacity of articular cartilage for self-repair is very limited, because it is a tissue without blood vessels. Damage to the surface therefore does not close on its own. The aim of treatment is to reduce symptoms and distribute load through the joint correctly.
Does a cartilage injury mean osteoarthritis?
No. A limited, sharply defined defect and wear spread across the whole joint (osteoarthritis) are different conditions. However, some untreated defects can over time predispose to widespread wear.
If I have a graft, will my cartilage be as it was?
The tissue formed after repair or grafting does not have exactly the same properties as natural articular cartilage. The aim is to reduce symptoms and improve function; no guarantee of a specific result is given.
Do supplements repair cartilage?
The evidence for these products is debated and the results are not consistent. If you are considering them, it would be appropriate to consult your physician regarding interactions with your current medication.
When can I walk after surgery?
The protection period after cartilage procedures is generally longer and weight-bearing is increased gradually. Your physician determines the exact timing according to the method used and your recovery.
Can I run?
Return to impact activities depends on the size of the defect, the method used and the course of recovery. Return is planned by criteria rather than the calendar; cycling and pool work are generally recommended earlier.
Academic Work
Assoc. Prof. Bertan Cengiz, MD has scientific work published in national and international peer-reviewed journals in the field of knee arthroscopy and joint-preserving surgery and related areas. The publication list and verifiable academic sources are available on the Publications page.
Related Pages
- Knee Arthroscopy
- Knee Osteoarthritis (Gonarthrosis)
- Meniscus Tear
- Anterior Cruciate Ligament (ACL) Injury
- Knee Arthroscopy Aftercare Guide
The information on this page is for general guidance and does not replace an in-person medical examination. Diagnosis and treatment require a physician’s clinical assessment. Outcomes of any treatment or surgical intervention may vary from person to person; no guarantee of a specific result or timeframe is given on this page.