Knee Arthroscopy

Arthroscopy means looking inside the joint through small incisions with a camera. It is often called keyhole surgery. It is a precise tool for specific problems and it has been widely overused for problems it does not solve.

When it is the right operation

• Meniscal tear causing mechanical symptoms: locking, catching, giving way, or a knee that will not straighten
• Loose body in the joint
• Cartilage procedures in selected cases
• Suspected joint infection, for washout and sampling
• As part of ligament reconstruction, such as ACL reconstruction

When it is not

For established osteoarthritis, arthroscopic washout and debridement does not provide meaningful benefit over non-surgical management, and recommending it for that indication is not supported by current evidence.

This matters because an arthritic knee often also has a degenerate meniscal tear on MRI. The tear is a finding, not necessarily the cause of the pain. Operating on the finding rather than the problem leads to a disappointed patient and an unchanged knee.

If your imaging shows arthritis and you are being offered an arthroscopy, ask what specific mechanical problem it is intended to fix, and what is expected to be different afterwards.

Repair or trim: an important distinction

• Meniscectomy trims away the torn portion. Quick recovery, but it removes tissue that protects the joint surface, which has consequences over years.
• Meniscal repair stitches the tear so the meniscus is preserved. Better for the long-term health of the joint, but it requires protected weight-bearing and restricted movement for several weeks and the recovery is much longer.

Not every tear is repairable. It depends on the pattern, the location, the blood supply and your age. Ask which is planned, and what the fallback is if the tear turns out not to be repairable once the surgeon can see it.

What the operation involves

Day surgery in most cases. Usually a general or spinal anaesthetic, two or three small incisions, and a procedure lasting typically 30 to 60 minutes depending on what is found and what is done.

Risks

Lower than open surgery, but not zero: infection, blood clots, stiffness, persistent swelling, injury to nerves or cartilage, and the possibility that symptoms are not resolved because the cause was not mechanical.

Common questions

Will an arthroscopy help my knee arthritis?

For established osteoarthritis, generally no. Arthroscopic washout and debridement for arthritic knees has been shown not to provide meaningful benefit over non-surgical management, and it is no longer recommended for that indication. It remains a useful operation for specific mechanical problems, which is a different situation from generalised joint wear.

What can an arthroscopy actually treat?

Repair or trimming of a torn meniscus, removal of loose bodies, treatment of a locked knee, cartilage procedures in selected cases, biopsy and washout for suspected infection, and as part of ligament reconstruction. The common thread is a specific mechanical target rather than general wear.

How long is the recovery?

Much shorter than open surgery. A simple arthroscopy for a trimmed meniscus often allows walking within days and return to desk work within a week or two. A meniscal repair, which is preserved rather than trimmed, requires protection for several weeks and a considerably longer recovery. Which one you have makes a large difference, so ask.

Related reading

Meniscus Tear

The difference between a traumatic and a degenerate meniscal tear, why that difference decides the treatment, and when surgery genuinely helps.

Knee Osteoarthritis

What knee osteoarthritis is, how it is assessed and graded, what actually helps at each stage, and when a joint replacement becomes the sensible option.