The first week after ACL surgery is about controlling swelling, protecting the graft, and starting gentle knee movement. Most of what you do during these seven days revolves around four priorities: keeping pain and inflammation in check, hitting early range-of-motion targets, waking up your quadriceps muscle, and caring for your incision. Here’s what each of those looks like in practice.
Swelling Control Sets the Tone for Everything Else
Swelling is the single biggest obstacle in your first week. It drives pain, it shuts down your quad muscle, and it limits how much you can bend or straighten your knee. Everything you do to reduce swelling pays off across all your other recovery goals.
Keep your leg elevated whenever you’re sitting or lying down, with pillows stacked so your ankle sits above your heart. Keep your knee straight while elevated. Do not place a rolled towel under the knee for comfort, even though it feels natural. That position can lead to a loss of full extension that becomes harder to recover later.
Ice your knee consistently. Apply cold therapy for 15 to 20 minutes at a time, multiple times throughout the day. If your surgeon sent you home with a cold-therapy unit that circulates ice water through a pad, use it. Compressive cryotherapy (cold plus compression together) has been shown to reduce swelling, pain, and medication use more than icing alone in the first three days. Cooling also helps counteract the reflexive muscle shutdown that happens after surgery by altering sensory signals traveling from your knee to your spinal cord.
What to Expect With Pain
Many surgeons now use a nerve block during the procedure. A single-injection block typically provides roughly 23 to 26 hours of pain relief, so expect a noticeable increase in discomfort on the first night or the morning after surgery as it wears off. Some patients go home with a small catheter that delivers local anesthetic continuously for three to five days, which smooths out that transition considerably.
Beyond the nerve block, your pain plan will likely include a combination of anti-inflammatory medication and, for breakthrough pain, a short course of opioid medication. The current approach is to layer several different types of pain relief together so that no single medication has to do all the work. Take your anti-inflammatory on a schedule rather than waiting until pain spikes. Staying ahead of pain is easier than chasing it.
Days two through four tend to be the peak for discomfort and swelling. By days five through seven, most people notice a meaningful drop in baseline pain, though the knee will still ache after exercises or periods of activity.
Range of Motion: Your Week-One Targets
You have two motion goals this week: full knee extension (straightening) and gradually increasing flexion (bending).
Extension is the more urgent target. In one large study tracking patients after ACL reconstruction, 95% achieved normal extension within the first week. Aim to straighten your knee completely, matching your other leg. Spending time with your leg propped up in a straight position counts as extension work, and it doubles as swelling control. Some surgeons recommend lying face-down and letting gravity gently pull your knee into extension, or placing your heel on a pillow with nothing supporting the back of your knee so it sags toward straight.
For flexion, a reasonable benchmark by the end of week one is around 90 degrees, roughly the angle your knee makes when you sit in a chair with your feet on the floor. Some patients reach well past that, with averages around 109 degrees reported in studies, but this varies by graft type, swelling level, and individual pain tolerance. Don’t force it. Gentle, repeated heel slides on a bed or smooth floor are the standard way to work on bending during this stage.
Waking Up Your Quadriceps
After ACL surgery, your brain’s ability to fire your quadriceps muscle drops dramatically. This isn’t just weakness from disuse. It’s a neurological reflex called arthrogenic muscle inhibition. Swelling inside the joint activates nerve fibers that send inhibitory signals to the motor neurons controlling your quad, essentially putting a governor on the muscle before you even try to use it. Pain amplifies the effect through a separate set of nerve fibers.
This is why quad activation exercises start immediately, often on the day of surgery or the day after. The core exercise is the quad set: while sitting or lying with your leg straight, tighten the muscle on top of your thigh and try to press the back of your knee flat into the surface beneath it. Hold for five to ten seconds, then relax. Three sets of ten repetitions, done daily, is a common starting protocol.
If you can’t get the muscle to fire at all, you’re not doing anything wrong. That inhibition reflex is powerful. Some physical therapists use neuromuscular electrical stimulation, which sends a mild electrical current through pads on your thigh to contract the quad externally while you try to contract it voluntarily. Biofeedback devices that show you the muscle’s electrical activity on a screen can also help you learn to recruit fibers you can’t yet feel. Ask your PT about these tools if your quad feels completely silent.
Other exercises typically assigned in the first week include ankle pumps (pointing and flexing your foot to promote blood flow), straight leg raises if your quad is firing well enough to keep your knee locked straight, and heel slides for flexion range of motion.
Walking and Weight Bearing
For a straightforward ACL reconstruction without meniscus repair or other ligament work, the standard approach is weight bearing as tolerated from day one. That means you can put as much weight through the leg as your pain allows, using crutches for balance and support. Most people use two crutches for the full first week and begin weaning off them in week two or three as confidence and quad control improve.
If your surgery involved a meniscus repair, cartilage procedure, or other additional work, your surgeon may restrict weight bearing or limit your range of motion. This is an important distinction. The “early weight bearing for everyone” approach has come under scrutiny in recent years, with orthopedic experts arguing that complex or multi-ligament knees need a more cautious, individualized plan. Follow whatever specific instructions your surgeon gave you, because they reflect what was actually done inside your knee.
Your Brace and Sleep
Most surgeons send you home in a hinged knee brace locked in full extension. Wear it whenever you’re up and moving during the first week. You should also wear it while sleeping for the first seven to ten days. This keeps you from accidentally bending the knee into a position that stresses the graft while you’re not awake to control it.
Sleeping will be uncomfortable. The best position for most people is on their back with the leg elevated on pillows. Some people manage to sleep on their side with a pillow between their knees, but the brace makes this awkward. Expect to wake up several times a night in the first few days. Icing before bed and timing your pain medication so a dose is active overnight can help.
Caring for Your Incision
You can change the surgical dressing 24 hours after the procedure. Remove any gauze but leave the small adhesive strips (steri-strips) over the incision in place. Cover the wounds with light gauze or adhesive bandages.
Once the incisions are dry and no longer draining, usually about two days after surgery, you can shower. Keep it brief, let water run over the incisions without scrubbing, and pat them dry with a clean towel immediately afterward. Do not soak in a bathtub, pool, or hot tub until your sutures or staples have been removed, which typically happens at your first post-operative visit around 10 to 14 days.
Warning Signs That Need Immediate Attention
Blood clots are a real risk after any lower-extremity surgery. The combination of reduced mobility, swelling, and surgical trauma creates conditions where clots can form in the deep veins of your leg. Watch for calf pain or tenderness that feels different from your surgical site pain, new swelling in your lower leg (not just the knee), warmth in one area of your leg, or skin that looks red or discolored.
A clot that travels to the lungs is a medical emergency. Symptoms include sudden shortness of breath, chest pain that worsens with breathing, and coughing up blood. If any of these occur, call emergency services immediately.
At the incision site, some drainage and bruising in the first 48 hours is normal. Signs of infection include increasing redness spreading outward from the incision, warmth at the wound site, thick or foul-smelling drainage, and fever above 101°F that persists.