A knee scope, formally called knee arthroscopy, is a minimally invasive surgery where a surgeon inserts a small camera and surgical tools through tiny incisions in your knee. The camera projects a live image of the inside of your joint onto a screen, allowing the surgeon to diagnose problems and repair damage without opening up the entire knee. It’s one of the most commonly performed orthopedic procedures in the United States.
How the Procedure Works
During a knee scope, your surgeon makes a few small incisions around the knee. Through one, they insert the arthroscope, a thin tube with a camera and light on the end. Through the others, they insert narrow surgical instruments to cut, shave, stitch, or remove damaged tissue. A sterile fluid is pumped into the joint to expand the space and improve visibility on the monitor.
The surgery can be done under general anesthesia (where you’re fully asleep), spinal or epidural anesthesia (where you’re numb from the waist down), or in some cases even local anesthesia. Regional options like spinal anesthesia tend to result in shorter hospital stays compared to general anesthesia. Most knee scopes are outpatient procedures, meaning you go home the same day.
Why You Might Need One
A knee scope is used both to diagnose and to treat a range of knee problems. The most common reasons include:
- Meniscus tears: The rubbery cartilage pads that cushion your knee are prone to tearing, especially during twisting movements or with age-related wear.
- Ligament tears: Damage to the ACL, PCL, MCL, or LCL can be repaired or reconstructed through the scope.
- Kneecap instability: If your kneecap repeatedly slips out of place, a scope can help correct the underlying problem.
- Arthritis-related damage: Loose fragments of cartilage or bone floating in the joint can be removed to reduce pain and catching.
Meniscus Surgery: Trim vs. Repair
Since meniscus tears are the single most common reason for a knee scope, it’s worth understanding the two main approaches. A partial meniscectomy trims away only the torn, unstable portion of the meniscus, leaving the rest intact. It’s the most frequently performed orthopedic operation in the country. A meniscal repair, by contrast, stitches the torn tissue back together to preserve the full meniscus.
Which approach your surgeon recommends depends on where the tear is located, how long you’ve had symptoms, your age, and whether the torn piece can be repositioned into place. Repair generally produces better long-term outcomes because keeping the meniscus intact preserves three critical functions: absorbing the forces that travel through your knee with every step, stabilizing the joint by improving how the bones fit together, and helping the joint surfaces glide smoothly. Removing meniscal tissue, even partially, increases the risk of developing osteoarthritis in that knee down the road.
What Recovery Looks Like
Recovery varies significantly depending on what was actually done during the procedure. A simple meniscus trim has a much shorter recovery than an ACL reconstruction or a meniscus repair, even though both go through the same small incisions.
For straightforward procedures like a partial meniscectomy, many people can bear weight the same day and return to desk work within a week or two. For more complex repairs, you may be restricted from putting weight on the leg for four to six weeks, using crutches in the meantime. Some protocols for combined ligament and meniscus repairs keep patients at partial weight-bearing for up to three months.
In the first two weeks, the focus is on managing swelling, restoring your range of motion, and getting your quadriceps muscles firing again. Icing and elevating your knee during this phase helps control pain and fluid buildup. From weeks two through six, physical therapy shifts toward building strength, walking with a normal gait, and improving your balance. After six weeks, the goal becomes returning to your previous activity level, whether that’s recreational sports, running, or simply walking without limitations.
Risks and Complications
Knee arthroscopy is considered low-risk as surgeries go, but no procedure is risk-free. Infection is the most common adverse event, though it remains rare. Blood clots in the leg (deep vein thrombosis) occur in roughly 0.4% to 2% of patients, depending on the study and whether preventive blood thinners are used. Major bleeding is very uncommon, occurring in about 0.1% of cases. Minor bleeding at the incision sites is more frequent but typically resolves on its own.
Other possible complications include stiffness if rehabilitation is delayed, nerve irritation near the incision sites, and persistent swelling. The small incisions heal quickly in most cases, leaving minimal scarring compared to traditional open knee surgery.
Physical Therapy After a Knee Scope
Rehabilitation is where the real work of recovery happens. A typical protocol moves through three phases. In the first two weeks, the priority is getting your knee to bend to about 120 degrees (roughly the angle of sitting in a low chair) and waking up your thigh muscles, which tend to shut down after knee surgery. During weeks two through six, you’re building endurance, working toward full pain-free range of motion, and retraining your body’s sense of joint position, which surgeons call proprioception. After six weeks, therapy progresses to sport-specific or activity-specific exercises aimed at getting you back to where you were before the injury.
How closely you follow your rehabilitation plan has a direct impact on your outcome. Skipping physical therapy or returning to activity too early increases the chance of re-injury or lingering stiffness. For meniscus repairs in particular, compliance with weight-bearing restrictions in the early weeks is essential to allow the stitched tissue to heal properly.