Knee arthroscopy

Introduction

The word 'arthroscopy' is derived for the two Greek words for 'joints' ('arthro') and 'see' (scopy') and is the medical term for what is known more widely as 'keyhole' or 'minimally invasive' surgery. Arthroscopic surgery on the knee is conducted both to examine the knee joint and to perform surgical procedures on it.

The main benefits of arthroscopic surgery over conventional surgery are:

  • Generally shorter operations.
  • Shorter postoperative recovery (most patients can return home on the day of surgery).
  • Minimal scarring.

Arthroscopic techniques are generally used in the following knee procedures:

  • Diagnostic examinations.
  • Clearing infection.
  • Removing loose sections of bone / cartilage.
  • Cyst removal (Bakers cysts are the most common cysts that affect the knee joint).
  • Repair / reconstruction of cartilage / meniscus / ligaments – e.g. ACL reconstruction.
  • Correction of patello-femoral issues (problems affecting the kneecap).
  • Partial knee replacement.
  • Synovectomy (to correct overproduction of synovial joint fluid).

Preoperative Instructions

  • Existing medication(s) – some medications can impact surgery, especially any anti-coagulant medication and medicine for diabetes; we will advise if any of your medication needs to be stopped (and when) well ahead of the day of surgery. Any other medication should be taken the morning of surgery with a little water (half a cup maximum).
  • You should not shave (or wax) skin near where any surgical incisions will be made.
  • No solid foods (cow's milk and drinks containing cow's milk are considered food) should be consumed within 6 hours of surgery; clear fluids (e.g. water, cordial) may be consumed until 3 hours before surgery and then nil by mouth from that point.
  • Please advise us if you have a cold or fever, a cough or any other injuries or infections (e.g. urinary tract infection or cuts / tears to the skin) – your procedure may need to be postponed as any of these may make anaesthesia or surgery unsafe.
  • Please bring all imaging (e.g. x-rays / CT scans / MRI scans) with you to hospital.
  • Please come to hospital at least one hour before your planned surgery, unless we advise you otherwise.

In very general terms make sure you follow a healthy and balanced diet before surgery and continue any regular physical activity up until the day of the procedure.  If you smoke, you should ideally stop smoking at least four weeks before the procedure and otherwise as a minimum at least one week before.

Procedure

Arthroscopic knee procedures involve the insertion of a very small video camera and special arthroscopic surgical instruments through small incisions around the knee. These incisions – called portals - are small (much smaller than incisions needed for conventional open surgery) at around 5mm-10mm in length and most procedures need 3-4 of these.

Arthroscopy is conducted under a general anaesthetic, although some procedures can be conducted under a type of local anaesthetic called a 'spinal' or 'regional' anaesthetic where the patient is awake during the procedure. If performed under general anaesthetic, a femoral nerve block anaesthetic may also be used – this allows a lighter form of general anaesthetic to be used.

Once the anaesthetic has taken effect and the necessary incisions have been made, a saline solution is used to allow adequate visualisation of the knee structures and before arthroscopic instruments are inserted. Once the specific procedure is completed, all instruments are withdrawn, the saline solution is drained, and the incisions are closed and dressed.

Postoperative instructions

After an arthroscopic procedure the patient is sent to the recovery room for observation for around two hours and at that point is generally allowed to return home. Patients are strongly advised not to drive, return to work or make any important decisions until the next day, due to the continuing effect of the anaesthetic. A crutch may be given to the patient if needed before returning home.

There is normally some pain after an arthroscopic procedure, so pain medication is supplied, and patients are advised to keep the affected leg elevated and apply an ice pack to the knee to help reduce any swelling.

Full recovery generally takes several weeks (see sections on each procedure for specific recovery guidelines) after arthroscopic surgery. With many procedures a recovery exercise program should be followed to reduce recovery time and allow full recovery of knee joint function.

Risks

As with any surgery, with arthroscopic surgery there is always a risk of:

  • Pain.
  • Bleeding.
  • Scarring.
  • Infection (of the incision site, or in the chest).
  • Blood clot (leg or lung).
  • Stroke.
  • Heart attack.
  • Damage to nerves / blood vessels.

Specific risks of arthroscopic knee surgery include:

  • Numbness / loss of feeling at the sites of incisions.
  • Continued pain in the foot / calf.