Most arthroscopic knee surgeries take about one hour in the operating room. Simpler procedures like removing loose cartilage can wrap up in under an hour, while more complex repairs may take up to two hours. But the time you actually spend at the surgical facility is longer than the procedure itself, typically three to five hours from check-in to discharge.
Operating Room Time by Procedure
The specific work being done inside your knee is the biggest factor in how long surgery takes. A straightforward diagnostic arthroscopy, where the surgeon inserts a small camera to inspect the joint, is one of the shortest procedures and often finishes well under an hour. Trimming or removing a torn piece of meniscus (a partial meniscectomy) also falls in that range, usually around an hour total.
A meniscus repair, where the surgeon stitches the torn cartilage back together rather than removing it, takes longer because the suturing is more precise work. ACL reconstruction is on the longer end, typically running one to two hours. That range widens if the surgeon needs to address multiple areas at once, such as repairing a ligament and trimming damaged cartilage in the same session.
What Adds Time to the Procedure
Several factors can push a surgery past its expected window. Higher body mass index is one of the strongest predictors of a longer operation, because more tissue between the skin and the joint makes access and visualization harder. Scar tissue from previous surgeries, the severity of arthritis, existing hardware in the knee, and unexpected findings once the camera is inside can all extend the procedure. Surgeons sometimes discover damage during the arthroscopy that wasn’t visible on imaging, which means additional work they hadn’t originally planned.
Time in the Recovery Room
After surgery, you’ll be moved to a recovery area where staff monitor you as the anesthesia wears off. This typically adds another one to two hours. The type of anesthesia plays a role here. General anesthesia (where you’re fully asleep) tends to clear faster than certain types of spinal anesthesia, which can numb your legs for a longer period and delay discharge. In one study comparing the two approaches for outpatient knee procedures, patients under general anesthesia spent roughly 30 fewer minutes in recovery than those given a longer-acting spinal block, though they reported more pain and nausea afterward.
Most people are alert and ready to leave within two hours of the procedure ending. You won’t be able to drive yourself home, so plan for someone to pick you up.
Your Full Day at the Facility
The surgical clock doesn’t capture your whole experience. You’ll typically arrive one to two hours before your scheduled procedure time. During that window, staff will check you in, confirm your medical history, place an IV line, mark the correct knee, and administer anesthesia. Adding that prep time to the surgery itself and the recovery room stay, most people spend somewhere between three and five hours at the facility for a standard arthroscopy.
Knee arthroscopy is almost always an outpatient procedure, meaning you go home the same day. There’s no overnight hospital stay unless complications arise or the surgery is combined with a more involved reconstruction.
Recovery Timeline After You Leave
How long the surgery takes in the operating room doesn’t necessarily predict how long your recovery will be. A partial meniscectomy, one of the shorter procedures, has a relatively quick recovery of about six weeks. A meniscus repair takes the same amount of time (or less) on the table but requires up to three months of healing, because the stitched cartilage needs time to knit back together inside the joint. ACL reconstruction carries the longest recovery, often six to nine months before full return to sports.
In the first few days after any arthroscopy, expect swelling, stiffness, and the need to ice and elevate the knee. Most people use crutches for at least a few days. Your surgeon will outline a specific plan for weight-bearing and physical therapy based on what was done during the procedure.