Keyhole procedure for cartilage repair provides greater convenience to patients with early kneecap osteoarthritis

Patients with early kneecap osteoarthritis and knee pain due to holes in the knee cartilage need about two months before they can fully regain mobility after traditional open knee surgery, and for active patients, a year before they can start running. But a new keyholebased procedure available at the Sengkang General Hospital (SKH) now shortens this time by half.

Cartilage is tissue that lines bone surfaces. It protects joints from stress by providing a smooth surface so bones can move against each other well. Osteoarthritis causes the cartilage in the knee joint to become thin and lose quality. As the cartilage wears out, holes form in the knee, causing pain, stiffness and reduced mobility.

Those who frequently squat or run, such as childcare teachers, cleaners and sportsmen, are most at risk. In early osteoarthritis, especially that of the patellofemoral region (kneecap), patients will feel pain when climbing stairs, said Dr Francis Wong, Consultant, Department of Orthopaedic Surgery, SKH. “The front or side of the knee aches. Next, the knee swells because the cartilage is not in its optimum condition, and more fluid builds up to increase the cushioning,” he said.

Another cause of early osteoarthritis, other than wear and tear of the cartilage,may be due to injury that causes the shock absorber of the knee, called the meniscus, to tear, resulting in pain.

During diagnosis, x-rays of the bones are taken to determine the severity of the arthritis and also to check for alignment of the knees. An MRI scan is also done to establish the sources of the defect, the location of the hole that is affecting the knee and how severe the condition is.

Initial treatment of osteoarthritis is conservative. Apart from physiotherapy to strengthen their thigh muscles, patients are advised to make lifestyle changes, such as to lose weight or modify their sporting activities by reducing intensity, or change their sport of choice. They may also be given medications and injections.

Operating table

Surgery is recommended as the last resort, or when the pain persists despite other measures.

During the operation, bone marrow is taken from the tibia below the patient’s injured knee. The marrow is then used to activate a synthetic piece of filler called a “scaffold”, which provides an environment that supports tissue growth, thus enabling the cartilage to re-form.

In conventional open knee surgery for kneecap osteoarthritis, the scaffolds are inserted into the knee and patients are then put on a knee brace for six weeks, during which they will require the use of crutches or frames. Due to its large size, the wound takes two to three weeks to heal. The joint eventually gets stronger and patients should be able to walk normally in about eight weeks. Open surgery is normally required to insert the scaffold for kneecap lesions due to their location, making keyhole surgery difficult. This leads to the large wound in the front of the knee, which then leads to a longer duration of recovery.

With the keyhole method, or arthroscopy, that SKH is pioneering in Singapore for early kneecap osteoarthritis, two small cuts, each less than 1cm in length, are made on either side of the knee. One cut is used to introduce the scaffolds into the knee; the other cut is where a camera is inserted during surgery for the surgeon to see the inside of the joint on a TV monitor. Patients stay in the hospital for two days, their wound heals in 10 days, and they are are able to start walking normally in three to four weeks. When they return home, patients are provided with an exercise regime based on their physiotherapist’s recommendations. They then receive followup physiotherapy every fortnight.

Recovery time for such patients is much shorter than via conventional surgery.

“They are moving around very well in three to four weeks, so they can take the brace out early,” said Dr Wong, adding that active patients who undergo keyhole surgery can usually go back to running in six months.

“We advise patients to seek help early when they realise that squatting hurts, or if knee pain lasts for more than two weeks. The earlier we detect the condition, the better we can provide solutions.”

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