ACL reconstruction surgery typically takes about 90 to 120 minutes from the first incision to the final dressing. An experienced surgeon working without trainees averages around 95 minutes, with individual cases ranging from 60 to 125 minutes depending on complexity. If a surgical resident is involved, as is common at teaching hospitals, the procedure averages closer to 137 minutes and can take up to 210 minutes.
What Affects the Length of Surgery
The single biggest factor in how long your surgery takes is who is performing it. A study from the University of Iowa tracked ACL reconstructions and found that attending surgeons completed the procedure in about 95 minutes on average, while cases involving residents averaged 137 minutes. That 40-minute difference is significant but expected. Residents are learning the procedure under supervision, and the additional time does not affect outcomes.
Beyond surgeon experience, several other factors influence total operating time. Additional damage inside the knee, such as a torn meniscus that needs repair, can add 15 to 45 minutes. The type of graft used matters too. Procedures using tissue harvested from your own body (like part of the patellar tendon or hamstring tendons) require extra time for graft preparation compared to using donor tissue. If your surgeon discovers unexpected cartilage damage once the camera is inside the joint, that extends the procedure as well.
Total Time You’re at the Hospital
The surgical time itself is only part of the picture. You’ll arrive one to two hours before your scheduled procedure for check-in, pre-operative preparation, and anesthesia. After surgery, you’ll spend one to two hours in a recovery room as the anesthesia wears off. Most people go home the same day, so the total time from arrival to discharge is roughly four to six hours.
If your surgery is scheduled at a teaching hospital and a resident will be assisting, it’s reasonable to expect the upper end of that range. You can ask your surgeon’s office ahead of time whether trainees will be involved.
What Happens During the Procedure
ACL reconstruction is performed arthroscopically, meaning the surgeon works through a few small incisions rather than opening the knee completely. A tiny camera goes into the joint so the surgeon can see the damage on a screen. The torn ligament is removed, and tunnels are drilled into the thighbone and shinbone to anchor the replacement graft. The graft is threaded through those tunnels and secured with small screws or other fixation devices.
Most of the surgical time is spent on graft preparation and precise tunnel placement. Getting the angles right on those bone tunnels is critical for long-term knee stability, so surgeons take care at this step rather than rushing. The actual removal of the torn ACL remnant is one of the quicker parts of the operation.
Anesthesia and What You’ll Feel
You’ll be under general anesthesia for the procedure, meaning you’re fully asleep and feel nothing. Some surgeons also use a regional nerve block, which numbs the leg and provides pain relief for several hours after you wake up. The nerve block is typically placed before surgery begins and is one reason you arrive well ahead of the scheduled start time.
When you wake up, your knee will be wrapped in a bulky dressing and often placed in a brace. Pain levels vary, but the nerve block keeps most people comfortable for the first 12 to 24 hours. Your surgical team will give you a pain management plan before you leave.
Recovery Timeline After Surgery
The short procedure time can be misleading. Although surgery takes under two hours, recovery is measured in months. Most people use crutches for two to four weeks and begin physical therapy within the first week. You can typically return to desk work in one to two weeks, though jobs requiring physical activity take longer.
The graft needs time to incorporate into the bone and develop its own blood supply, a biological process that takes about three months. Full return to cutting and pivoting sports like soccer, basketball, or skiing generally happens at six to nine months, assuming rehabilitation milestones are met. Some surgeons recommend waiting a full year before returning to high-level competition, particularly for younger athletes.