Knee arthroscopy

SUMMARY

  • Knee arthroscopy is keyhole surgery of the knee
  • It is normally performed through 2 or 3 small incisions at the front of the knee
  • Most arthroscopies are done as a day case procedure
  • During knee arthroscopy, various procedures can be performed, such as cartilage trimming or repair


 
Arthroscopy of the knee means keyhole surgery of the joint. Knee arthroscopy was first introduced into the UK in the 1970s and has grown to be one of the most commonly performed Orthopaedic procedures.

Why might I need a knee arthroscopy?

There are a large number of different conditions that can cause symptoms within the knee joint. The main symptoms that typically might suggest that a knee arthroscopy could be necessary are:-

  • Pain in the knee (especially sudden sharp pain)
  • Intermittent swelling (this is often associated with conditions such as meniscal tears)
  • 'Giving way' (this is where the knee ligaments are damaged, causing instability, or it can be caused by loose or torn pieces of cartilage catching inside the knee)
  • Locking (which can be due to cartilage loose bodies or unstable flaps from meniscal cartilage tears).

How is an arthroscopy performed?

Knee arthroscopy is normally performed under a short general anaesthetic, lasting usually somewhere between 30 to 45 minutes. Two small (1cm) incisions ('portals') are made at the front of the knee (either side of the patellar tendon). Sometimes it is necessary to create additional incisions if better visualisation inside the knee is necessary.

The knee is filled with pressurized fluid, to help give a good view of the interior of the joint. A 3.5mm diameter telescope is inserted into the knee with a digital camera attached to the end, giving a high quality image on a monitor, viewed by the operating surgeon. Special probes and other tools can be inserted through the second portal, enabling minimally invasive interventional surgery to be performed.

 
Intra-articular view of a knee through an arthroscope: 
top = femoral condyle, 
bottom = tibial plateau, 
back = meniscus, 
front = arthroscopy probe.

What arthroscopic procedures can be performed?

The range of procedures that can be performed at the time of standard knee arthroscopy include:-

 

Loose bodies in synovial chondromatosis 

  • Microfracture for treatment of bare bone cartilage defects
  • Medial plica excision
  • Excision of scarring of the fat pad
  • Lateral release to correct patellar tilting / maltracking
  • Debridement of ragged ligament tissue from ACL ruptures

What should I expect post-operatively?

At the end of the procedure the knee is filled with local anaesthetic. In addition, painkillers are normally administered by the anaesthetist. It is normal to have some discomfort in the knee initially on waking up from the anaesthetic. However, if the knee is significantly painful then it is important for you to indicate this to the nursing staff in the recovery section of the theatres department or back on the ward, as they have ready access to whatever additional strong painkillers might be necessary.

How one feels in the early post-op period depends on the length of the anaesthetic given, the patient's reaction to the anaesthetic, the pathology found within the knee and the amount and magnitude of the surgical procedures undertaken arthroscopically.

If only relatively minor surgery has been performed inside the knee, then most patients can fully weight bear pretty much straight away post-operatively, often without any aids but sometimes with the temporary help of a crutch. However, if more major surgery (such as articular cartilage repair or meniscal repair) has been performed, then a slower, more careful rehab regime will be needed in order to protect the knee and the surgical repairs. This can involve the use of a hinged knee brace plus crutches for up to 6 weeks, with regular intensive physiotherapy treatments.