Damage to the smooth lining inside your knee
A sports medicine knee surgeon and a physical therapist explain cartilage injuries
Smooth cartilage coats the ends of the bones in your knee. It’s separate from the two menisci, which act as cushions between the bones. A direct blow or a dislocated joint can damage that smooth coating. Sometimes the bone underneath is hurt too. Swelling, pain when you put weight on the leg or catching may linger after the first bruises fade. A piece that breaks free can cause the knee to lock. [1, 2]
What scans can and can't show
A regular X ray may reveal a piece of bone that broke off. It often misses cartilage damage that occurs on its own, though. An MRI may show the damaged area along with any ligament or meniscus damage. [1, 2]
Ask if the finding is a fresh injury in one spot or wear that is more widespread. Ask, too, whether any fragment has come loose in the joint. These details shape whether rehab, watching it over time or a procedure makes sense. [1, 2]
Pick a plan for your own knee
Some injuries can be handled by bringing down swelling, building strength and changing activity. A fragment that has moved out of place may lead to a talk about surgery. So can a defect in one spot that won’t go away. [1, 2]
Cartilage restoration procedures vary. Not everyone gets the same benefit from them. Ask what the proposed procedure is meant to fix. Find out what walking limits follow and how long rehab may take. Fixing an unstable ligament may matter as well. [1, 2]
Report a knee that won't straighten
Call your knee team if the joint will not straighten at all, keeps catching or swells again after normal activity. Get urgent care if your foot turns cold or pale after a severe knee injury. [1]
Questions about cartilage and loose pieces
- Is the damage to the joint surface cartilage, the meniscus or both?
- Is there a loose piece inside my knee?
- What would make a procedure worth it for me?
Keep a swelling and locking diary
Keep brief notes on swelling and on any times the knee catches or locks. [1]
Sources and further reading
- 1American Orthopaedic Society for Sports Medicine, articular cartilage injuries
- 2American Academy of Orthopaedic Surgeons, articular cartilage restoration
This article shares general information from knee surgeons and physical therapists. How big the damaged area of joint surface is and where it sits will guide treatment. So will any loose fragments, other injuries and your own goals.
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