Knee Arthroscopy

Patient information — Dr Christopher Spelman, Orthopaedic Surgeon

Overview

Knee arthroscopy is keyhole surgery of the knee. Through two small incisions (portals), a camera and fine instruments are placed into the joint, allowing the surfaces to be inspected and many problems treated with less disruption than open surgery. It is usually performed as day surgery, under general or spinal anaesthetic.

What it is used for

Knee arthroscopy is a versatile tool. Common reasons include:

●      Meniscal tears – repairing the meniscus (stitching it) where the tear is suitable, or trimming the torn portion, especially where the knee is catching or locking

●      Cartilage injuries – assessing and treating focal cartilage defects

●      Removing loose fragments of cartilage or bone (loose bodies), which can cause locking

●      As part of ligament surgery, such as ACL reconstruction, and to treat some problems of the joint lining (synovium)

Importantly, knee arthroscopy is not an effective treatment for osteoarthritis on its own, and is not used simply to “wash out” or “clean up” an arthritic knee.

Recovery

For simple procedures such as trimming a meniscus or removing a loose body, recovery is usually quick, with a return to most daily activities over a few weeks and crutches for only a short period. Procedures such as a meniscal repair or cartilage surgery need a more protected and longer rehabilitation – often a period of restricted weight-bearing and limited bending – because the tissue must heal.

What the evidence shows

High-quality evidence has refined when knee arthroscopy is worthwhile. For a degenerative meniscal tear, or for knee arthritis without true mechanical locking, several randomised trials have shown arthroscopy to be no better than physiotherapy or a placebo (sham) procedure – so it is not recommended in that setting. It retains a clear and important role for mechanical symptoms (catching, locking), repairable (usually traumatic) meniscal tears, focal cartilage injuries, loose bodies and ligament reconstruction, where it is genuinely effective.

Complications

Knee arthroscopy is one of the safest surgical procedures, with a low overall complication rate, but risks include:

●      Infection (septic arthritis) – uncommon (well under 1%) but serious, and may require further surgery and antibiotics

●      Blood clots – deep vein thrombosis and, rarely, pulmonary embolism; the risk is low, and the need for blood-thinning prophylaxis is judged individually

●      Stiffness or an effusion (swelling) that takes time to settle

●      Numbness around the incisions, particularly a small patch below the knee from a skin nerve (the infrapatellar branch of the saphenous nerve)

●      Persistent or recurrent symptoms, particularly where there is underlying cartilage wear, and (rarely) a persistent pain condition such as complex regional pain syndrome

Summary

Knee arthroscopy is an effective, minimally invasive way to treat meniscal tears, cartilage injuries and loose bodies, and to perform ligament surgery – but it is not a treatment for arthritis alone. Dr Spelman will advise whether arthroscopy is appropriate for your knee and what it can realistically achieve.