What Is Knee Arthroscopy? Keyhole Knee Surgery Explained

You may have been told that you need ‘keyhole surgery’ on your knee, or perhaps you have heard the term ‘knee scope’. These phrases usually refer to a procedure called knee arthroscopy. It is a very common surgical technique used by orthopaedic surgeons to both diagnose and treat a wide range of problems inside the knee joint. This article offers a straightforward explanation of what a knee arthroscopy is, why it is performed, and what you can generally expect if you and your surgeon decide it is the right step for you. The goal is to provide clear information, but it cannot replace a personal medical consultation.

What Happens During a Knee Arthroscopy?

Knee arthroscopy uses a specialised camera, called an arthroscope, which is about the thickness of a pencil. This camera is connected to a high-definition monitor in the operating theatre.

Instead of making a large incision, the surgeon makes two or three very small cuts, often called portals, around your knee. These are typically less than a centimetre long. The arthroscope is passed through one portal, and fine surgical instruments are passed through the others.

To create a clear view, the knee joint is gently filled with a sterile fluid (saline). This expands the space within the joint, allowing the surgeon to see the internal structures, such as the cartilage surfaces, the meniscus, and the ligaments, in great detail on the screen.

This view allows the surgeon to confirm a diagnosis and, in most cases, carry out the necessary treatment during the same procedure. The entire operation is performed by watching the monitor, which provides a magnified and brightly lit view inside your knee.

Why Use Keyhole Surgery Instead of an Open Operation?

The primary advantage of an arthroscopy procedure is that it is minimally invasive. This means it causes far less disruption to the muscles, ligaments, and capsule around the knee joint compared to a traditional open operation which requires a much larger incision.

Because the surrounding healthy tissues are disturbed less, patients often experience less pain immediately after the surgery. This can help in the early stages of recovery.

It is important to understand that keyhole knee surgery is not suitable for every knee problem. Conditions like a complex fracture or the placement of a total knee replacement require an open approach. The decision about the best surgical method is always based on your specific diagnosis, a conclusion reached after a thorough discussion with your surgeon.

Common Reasons for a Knee Arthroscopy Procedure

Knee arthroscopy is a versatile tool. Some of the most common reasons a surgeon may recommend this procedure include:

Torn Meniscus: The menisci are two C-shaped pieces of shock-absorbing cartilage in the knee. Tears are common. Depending on the type and location of the tear, the surgeon may be able to trim away the damaged portion (a partial meniscectomy) or, in some cases, perform a meniscus repair.

Anterior Cruciate Ligament (ACL) Reconstruction: While the full operation is more involved than a simple arthroscopy, the keyhole technique is the standard way to prepare the knee and pass the new ligament graft during an ACL reconstruction.

Removal of Loose Bodies: Small fragments of bone or cartilage can break off and float within the joint, causing pain, catching, or locking. Arthroscopy is often used to find and remove these.

Treating Cartilage Damage: In some cases of localised damage to the smooth articular cartilage covering the ends of the bones, arthroscopy can be used for procedures aimed at encouraging new cartilage growth or smoothing the damaged area.

Diagnostic Arthroscopy: Occasionally, even after a physical examination and an MRI scan, the exact cause of knee pain remains unclear. In these selected situations, a diagnostic arthroscopy knee procedure allows the surgeon to look directly inside the joint, which can help clarify the diagnosis.

When Knee Arthroscopy Is Generally Not the Answer

It is just as important to understand what knee arthroscopy is not used for. A common question from patients is whether keyhole surgery can 'clean out' an arthritic knee.

For the vast majority of patients with established, widespread osteoarthritis, knee arthroscopy is not considered an effective treatment. Osteoarthritis is a condition that affects the entire joint surface, and simply 'washing out' the joint (a lavage) or 'tidying up' rough cartilage (a debridement) has not been shown in major studies to provide reliable, long-term relief from arthritic pain.

While a patient with arthritis might also have a problem like a meniscal tear that could benefit from arthroscopy, the procedure is not a cure for the underlying arthritis itself. Treatment for osteoarthritis is a separate pathway, involving options from physiotherapy and injections to knee replacement surgery, and this is best discussed in detail with your surgeon.

What to Expect on the Day of Your Surgery

On the day of your operation, you will be admitted to the hospital. You will meet the nursing staff and the anaesthetist, who will discuss the anaesthetic plan with you.

A knee arthroscopy is most commonly performed under either a general anaesthetic, where you are asleep for the procedure, or a spinal anaesthetic, where you are awake but numb from the waist down. The choice depends on your health and your preference, and is made in consultation with the anaesthetist.

The surgery itself is usually quite quick, often taking less than an hour, though the total time in the theatre area is longer. Afterwards, you will be taken to a recovery room to be monitored as the anaesthetic wears off.

You will wake up with a small, padded dressing on your knee. Many knee arthroscopy procedures are performed as day-case surgery, meaning you can go home the same day. However, an overnight stay may be planned depending on the specific surgery performed, the time of your operation, or your individual needs.

Recovery and Rehabilitation After Keyhole Knee Surgery

Your recovery journey depends almost entirely on what was done inside your knee. A simple diagnostic look or a minor trimming of a meniscus has a very different recovery path compared to a complex ligament reconstruction or a meniscus repair.

It is normal to have some swelling, stiffness, and discomfort in the first days and weeks. Your surgeon will advise on pain relief medication. Some patients may need to use crutches for a short period, either for comfort or to protect a repair.

Rehabilitation with a physiotherapist is often recommended to support recovery after many knee arthroscopy procedures. Your physiotherapist will guide you through exercises to restore your range of motion, strength, and function.

Timelines for returning to driving, work, and sports are highly individual. These decisions are not based on a fixed schedule but on your personal progress, and they will be discussed with you by your surgeon at your follow-up appointments.

Understanding the General Risks

Before you agree to any operation, your surgeon will have a detailed conversation with you about the potential risks and complications. This is a standard part of the consent process. For knee arthroscopy, the commonly discussed risks include:

Infection: A risk with any procedure that breaks the skin, though it is generally uncommon for arthroscopy.

Blood Clots: A clot in the deep veins of the leg (DVT) is a potential risk after any lower limb surgery. Your team will take steps to minimise this risk.

Stiffness: The knee can sometimes become stiff after surgery. Following the advice of your surgeon and physiotherapist can help manage or reduce it.

Nerve or Vessel Injury: There are small nerves and blood vessels around the knee that could potentially be bruised or damaged, which is rare. This can sometimes cause a small patch of numbness near one of the incisions.

Ongoing Symptoms: It is possible that the procedure may not fully relieve all of your symptoms, or that the findings inside the knee are different from what an MRI scan suggested.

Signs That May Require Prompt Medical Review

After you are discharged home, there are certain signs that are generally regarded as reasons for seeking prompt medical advice, rather than waiting for your next planned appointment.

These include developing a high temperature or fever, or feeling generally unwell; experiencing severe or escalating pain in the knee that is not managed by your prescribed pain medication; noticing significant redness, heat, or any fluid discharge from the incision sites; or developing sudden, severe pain, swelling, and tenderness in your calf muscle.

In any of these situations, it is advisable to contact the surgical team or the hospital where your procedure was performed for guidance.

Your Personalised Assessment

This article provides a general overview of knee arthroscopy, but it cannot tell you what is right for your specific situation. Every patient and every knee is unique. An effective treatment plan is typically based on an accurate diagnosis and a clear understanding of your symptoms, activities, and goals.

To discuss your knee problem and determine if keyhole knee surgery is an appropriate option for you, a formal consultation is essential. Dr. Farooq Azam Khan is a consultant orthopaedic and joint replacement surgeon in Lahore who consults on the choices for your care.