The most common reason for knee arthroscopy is a tear of the meniscus (or “cartilage”) within the knee. This usually presents as a localized area of pain in the knee and often has a sudden onset after a minor twisting episode. It has often but not always been confirmed using an MRI scan prior to surgery. Usually a period of a few weeks will be given to see if the tear will settle spontaneously and thus avoid the need for surgery.
Other common reasons for surgery include locking of the knee joint where a patient notices on occasion that they are unable to either bend or fully straighten the knee. This can be due to either a large tear of the meniscus or a loose body moving around the joint. Also occasionally, localised damage to the surface of the joint itself can be addressed with arthroscopy however as a rule, arthroscopy is a poor choice of operation for patients with well established arthritis.
Knee arthroscopy is usually performed under a general anaesthetic i.e you are fully put to sleep for the duration of the operation. Occasionally, a spinal anaesthetic may be used whereby the legs are numbed from an injection of local anaesthetic into your back however this can be discussed with the Anaesthetist prior to surgery.
A tight band or tourniquet is inflated around your thigh to ensure a bloodless view during the surgery. Occasionally your thigh may be mildly uncomfortable or look bruised after surgery because of this.
A knee arthroscopy or keyhole surgery involves the insertion of a small camera (just smaller than a pencil) into the knee joint via a stab incision. A second stab incision allows instruments such as a probe or shaver to be inserted. In addition, the joint itself is filled with sterile fluid to make it easier to fully assess the joint and perform any tasks deemed necessary.
The most common finding is a torn meniscus or torn cartilage as it is often called. Because of the relatively poor blood supply to the meniscus, most tears are not repairable and in this case, only the torn portion of the meniscus is removed - a partial meniscectomy. If the tear is large and deemed to have the potential to heal, it can be sutured back in place - a meniscal repair.
Meniscal tear and post-menisectomy picture
Damage to the surface of the joint itself can be dealt with by drilling some small holes into the area, a process known as microfracture. This hopefully stimulates the production of healing cartilage in the area but is only used when the damage is relatively small and localized.
Any loose bodies that are moving around the joint can also be removed.
The bulky wool & crepe bandage can be removed 24 hours after surgery. It is normal for the waterproof dressings underneath to have a small amount of blood on them and they can be replaced at this point. It is fine to shower but avoid getting too much water directly on the dressings. Some of the fluid that was used to fill the knee joint during the surgery can also leak out in the first couple of days and this is normal.
Normally 2 but up to 4 scars will be present around the kneecap depending on the exact procedure performed. These will be approximately 1 cm long. They are closed with paper stitches (steristrips) that can be removed 7 to 10 days after the surgery.
At the end of the procedure, some local anaesthetic is injected into the knee joint. This will usually but not always ensure minimal pain following the surgery. However, as the local anaesthetic begins to wear off (usually approximately 12 - 24 hours post surgery), some discomfort can return. Simple analgesia such as Paracetamol or Paracetamol with codeine or occasionally an anti-inflammatory should suffice at this point.
Whilst early activity is generally encouraged, you may also find that elevating the leg and placing an ice pack (or bag of frozen peas), wrapped in a towel, across the knee greatly helps to alleviate both pain and swelling.
Obviously this depends on both the individual & nature of the work. As a rule, an office worker can expect to return to work after 2 - 3 days whereas a manual worker may require 1 - 2 weeks off. Whilst a return to normal activities is in general recommended, an increase in pain and / or swelling may simply mean that activities need to be reduced somewhat for a couple of days.
Compiled October 2015
Review date: March 2016
Review date: March 2016