Knee Arthroscopy
What Is Knee Arthroscopy?
Knee arthroscopy is keyhole knee surgery in which the inside of the joint is inspected through a slim camera (an arthroscope) passed through incisions only a few millimetres long and, where necessary, repaired in the same session with fine instruments. Because the view is projected onto a screen, the articular cartilage, both menisci, the cruciate ligaments and the joint lining can be assessed under magnification. Sparing the surrounding soft tissue generally means less early pain and swelling than open surgery and an earlier start to movement. Arthroscopy is nevertheless a means of access rather than a treatment in itself: the outcome depends on what is found inside the joint and on the procedure used to address it.
Arthroscopy is now rarely used for diagnosis alone. Magnetic resonance imaging (MRI) shows most of the structures inside the knee without an operation, so the decision weighs the history, the examination and the imaging together, and surgery is considered only when a treatable mechanical problem has been identified. For a broader picture of how the knee is built and the conditions that affect it, the knee overview is a useful starting point.
Which Problems Is It Used For?
Arthroscopy helps most when there is a mechanical block inside the knee or a repairable structural injury. Common indications include:
- Meniscal tears that cause catching, locking or giving way, and root or bucket-handle tears that are suitable for repair.
- Anterior or posterior cruciate ligament tears, where the reconstruction is carried out under arthroscopic guidance.
- Contained cartilage defects with well-defined edges, and selected cartilage repair or restoration procedures.
- Removal of loose fragments of cartilage or bone that move within the joint and cause it to catch.
- Selected soft-tissue problems such as persistent inflammation of the joint lining (synovitis) or symptomatic plica.
- Certain fractures that extend into the joint, where the fracture line is assessed and reduced with arthroscopic assistance.
Each of these headings must be judged on its own merits. A meniscus tear in a young athlete that is amenable to stitching is not managed in the same way as an age-related degenerative tear. Likewise, when a knee cartilage injury is found, the size and depth of the lesion and the alignment of the leg directly affect which treatment is appropriate.
Who Is a Candidate, and Who Is Not?
The best candidates are people whose examination and imaging findings match their symptoms, who have true catching, locking or a clear structural injury, and whose function remains limited despite an adequate course of non-operative treatment. By contrast, routine arthroscopic washout and debridement is not recommended in advanced knee osteoarthritis, where the joint space is markedly narrowed and the pain is diffuse. Degenerative meniscal tears without mechanical symptoms are also best managed first with a structured exercise programme. Active skin infection over the planned incisions, uncontrolled systemic illness and circumstances in which rehabilitation cannot realistically be followed may delay the operation or change the plan. The non-operative steps for a worn joint are set out on the knee osteoarthritis treatment page.
Preparation Before Surgery
Before surgery the history, a detailed knee examination and the imaging are reviewed together: weight-bearing X-rays show the joint space and the alignment of the leg, while MRI shows the state of the menisci, ligaments and cartilage. Medication, blood thinners, smoking and coexisting illnesses are reviewed, and blood tests or a separate anaesthetic assessment are requested where needed. The scope of the operation, the expected benefit, the alternatives, the risks and the length of rehabilitation are explained, along with how the plan might change if something unexpected is found inside the joint. Quadriceps exercises started beforehand make it easier to regain thigh muscle control afterwards, and practical arrangements such as fasting times, transport home and crutches are best organised in advance.
How the Operation Is Done: Techniques
Two or three portals a few millimetres wide are usually made around the knee. The camera passes through one and fine instruments through another, and the joint is gently distended with sterile fluid to open up the view. The surgeon first inspects the whole joint systematically: the articular cartilage, the medial and lateral menisci, the cruciate ligaments, the joint lining and the surface between the kneecap and the thigh bone are each examined in turn, which can reveal findings not fully visible on preoperative imaging.
The appropriate procedure is then carried out for whatever has been found. A torn meniscus is stitched back together if its position and blood supply allow; where a tear is not repairable, only the torn portion is trimmed and as much healthy tissue as possible is preserved. Cartilage lesions may be managed by tidying the edges, by techniques that stimulate the bone marrow or, in selected cases, by graft-based restoration. In cruciate ligament reconstruction the graft is passed through bone tunnels created under arthroscopic guidance and fixed in place. The options for the meniscus are covered on the meniscus surgery page.
Anaesthesia and Duration
Knee arthroscopy may be performed under general anaesthesia or under regional (spinal) anaesthesia; the choice depends on general health, the planned scope of the operation and the assessment of the anaesthetic team. A nerve block, or a long-acting local anaesthetic placed in and around the joint, may be added to help with pain in the first hours afterwards. Operating time varies considerably with what is done: a limited meniscal procedure can be short, whereas a ligament reconstruction or a cartilage restoration takes appreciably longer. Most isolated procedures are planned as day surgery, while an overnight stay may be preferred for more extensive work.
The First Period After Surgery
For the first few days the knee is usually bandaged and somewhat swollen. Ice, elevating the leg above the level of the heart and the prescribed pain relief help settle pain and swelling, and the dressings are kept clean and dry until the surgical team advises otherwise. Ankle pumping movements and static quadriceps contractions are encouraged from the first day, as they maintain muscle activation and support circulation in the leg. Weight-bearing and the use of crutches depend on what was done: early weight-bearing may be allowed after a limited meniscal trim, whereas a meniscal repair, a cartilage procedure or ligament surgery often calls for a period of protected weight-bearing. Increasing leg pain with one-sided calf swelling, redness and tenderness should be assessed for deep vein thrombosis.
Rehabilitation and Physiotherapy
Rehabilitation is one of the strongest determinants of the result after arthroscopic knee surgery, and it is guided by goals reached rather than by a fixed calendar. The first phase aims to control swelling, restore full extension and switch the quadriceps back on. Range of motion is then increased in stages alongside strengthening that also addresses the hip and calf, followed by balance, proprioception and single-leg control, and finally by movements specific to the person's job or sport. The pace differs with the procedure: after a meniscal repair or a cartilage restoration, movement and load are deliberately restricted for a defined period, while progress can be quicker after a limited trim.
Return to Work and Sport
Return to desk-based work is often possible fairly soon, once swelling and pain are controlled and you can move about safely; jobs that involve prolonged standing, stairs, squatting or carrying loads take longer. Driving is resumed only when reflexes and muscle control are reliable, protected weight-bearing has ended and sedating pain medication is no longer being taken. Return to sport is governed by criteria rather than by dates: absence of swelling, full range of motion, thigh strength approaching that of the other leg and pain-free running and controlled hop tests. How long that takes varies with the procedure, the starting condition of the knee and adherence to rehabilitation, so no fixed date is promised.
Risks and Complications
Although arthroscopy is minimally invasive, it remains an operation and carries its own risks. These include bleeding into the joint (haemarthrosis), superficial or deep infection, stiffness and excessive scar tissue formation (arthrofibrosis), numbness around the portals from irritation of the small skin nerves, persistent swelling, injury to nerves or blood vessels, and clot formation in the leg veins. The general risks of anaesthesia are assessed separately. A repair may also fail to heal as hoped, or symptoms may persist, in which case further assessment and sometimes a further procedure are needed. Marked and progressive loss of movement should be addressed early, because established stiffness is harder to treat. The overall risk profile varies with age, coexisting illness, smoking and the extent of the procedure performed.
Factors Affecting the Outcome and Alternatives
The result is shaped mainly by the type and size of the problem found, the overall condition of the articular cartilage, the alignment of the leg, the person's age and activity level, and adherence to rehabilitation. In a knee where the cartilage is widely worn, the gain expected from arthroscopy is more limited than in a knee with healthy cartilage and an isolated meniscal tear; discussing that difference openly beforehand is what builds a realistic expectation. Alternatives include structured exercise and physiotherapy, weight management, activity modification, intra-articular injections in selected cases and, where malalignment is significant, a knee osteotomy that shifts load onto the healthier compartment. In advanced arthritis, partial or total knee replacement is a separate option.
When Should You See a Doctor?
After surgery, pain that increases and does not respond to the prescribed medication, swelling that keeps growing, drainage from the incisions, redness, fever, one-sided calf swelling and tenderness, numbness or weakness in the foot, or sudden shortness of breath should all be assessed without delay. Before surgery, a knee that locks, that repeatedly gives way or swells, or that remains painful and limits daily life despite an adequate course of non-operative treatment is reason enough for a proper assessment. To have your knee symptoms evaluated, you can contact Assoc. Prof. Serkan Sürücü.