The bone ends are covered with smooth surface to allow the joint to move without catching. This can be damaged and result in pain and swelling (as well as a catching sensation).

Depending on the size and position of this injury, it may be possible to either smooth this cartilage (to limit the catching and progression) or attempt to fill in the hole in the cartilage.

Most procedures are performed via two small (1-2 cm) incisions at the front of the knee. The knee is filled with water and a camera is used to look around the joint.

Chondroplasty - this procedure uses either an electrical field or a mechanical shaver to remove loose fragments and seal the injury to prevent it increasing in size.

Microfracture - when there is a small area of damage that extends down to the bone, it may be possible to fill the hole with scar tissue to give a smooth surface back. This involves drilling small holes in the base of the defect to get some bleeding in the area and encourage a scab to form. This is not the same as the original cartilage but can relieve some of the symptoms.

Both procedures take about 30 minutes with the anaesthetic and recovery meaning the operation takes about 1-1.5 hours.

Most patients have a general anaesthetic. Following the procedure, local anaesthetic is used to control post-operative pain. The incisions are closed with sutures and a dressing is applied. A bandage is used to limit swelling and pain after the operation.

Most patients can be discharged the same day. Following chondroplasty, most patients will be allowed to start using the knee immediately. Following microfracture, it is important to give the area time to heal so crutches are used for 6 weeks and specific exercises are given.

Most patients require simple painkillers for upto  2 weeks and are comfortable by 6 weeks.

The bandage can be removed 24-48 hours following the operation.

Patients are routinely reviewed at 2 weeks (to ensure the wounds have healed and remove sutures) and 6-8 weeks (to ensure pain is settling and function is returning). Further appointments are often necessary following microfracture.