Yes, you can still grow after ACL surgery. The vast majority of young patients who undergo ACL reconstruction continue growing normally afterward. In a large systematic review covering 2,693 pediatric ACL reconstructions, only 2.6% experienced any measurable growth disturbance. Modern surgical techniques are specifically designed to protect the growth plates in younger patients, and surgeons choose their approach based on how much growing you have left to do.
That said, the concern is legitimate. ACL surgery involves drilling tunnels through bone to anchor the new ligament, and in skeletally immature patients, those tunnels can come close to or cross through the growth plates near the knee. Understanding how surgeons manage that risk can help you know what to expect.
Why Growth Plates Matter in ACL Surgery
The knee has two major growth plates: one at the bottom of the thighbone (femur) and one at the top of the shinbone (tibia). These are the areas responsible for most of your leg’s lengthening during adolescence. In a standard adult ACL reconstruction, the surgeon drills tunnels straight through both of these growth plates. For someone who’s done growing, that’s no problem. For a teenager or younger child, a tunnel through a growth plate can potentially disrupt the cells that drive bone lengthening.
The amount of disruption depends on how much of the growth plate is affected. Research using MRI scans after surgery found that even techniques designed to spare the growth plates still touched the tibial growth plate in most patients, but the area disturbed was small, averaging about 1.7% of the total plate area with the most protective methods. Compare that to a partial transphyseal technique, which disturbed about 7.3% of the tibial growth plate. In both cases, the femoral growth plate was rarely affected, with disturbance around 1.5% when it occurred at all.
How Surgeons Protect Growing Bones
Surgeons don’t use a one-size-fits-all approach for younger patients. They select a technique based on your stage of physical development (assessed using Tanner staging, which tracks puberty markers) and how much growth you have remaining. A hand and wrist X-ray, evaluated using a method called the Greulich-Pyle atlas, helps estimate your bone age and remaining growth potential.
For the youngest patients (Tanner stages 1 and 2, typically girls under 10 and boys under 12) who still have more than 5 to 7 centimeters of growth left, surgeons use techniques that completely avoid the growth plates. These include all-epiphyseal methods, where tunnels are placed entirely within the bony caps above and below the growth plates, or extra-articular reconstructions that route the graft around the outside of the joint.
For patients in mid-puberty (Tanner stage 3), a hybrid approach is common. The femoral side uses a growth plate-sparing method while a single vertical tunnel crosses the tibial growth plate. This balances the need for a stable reconstruction with growth protection. By this stage, patients typically have only 1 to 5 centimeters of growth remaining.
Adolescents nearing skeletal maturity (girls around 13 to 14, boys around 15 to 16) with less than a centimeter of growth left generally receive the same transphyseal reconstruction adults get. At this point, the growth plates are nearly closed and the risk of disturbance is negligible.
What Growth Disturbance Looks Like
When growth problems do occur after ACL surgery, they fall into a few categories. Among the 70 cases of growth disturbance identified across nearly 2,700 surgeries in one systematic review, 26 involved the leg angling inward (valgus), 17 involved the leg angling outward (varus), 13 resulted in the operated leg being shorter, and 14 actually resulted in the leg growing longer than the other side. Five patients developed a change in the angle of the tibial plateau.
These numbers are reassuring in context. A 2.6% overall rate means roughly 97 out of 100 young patients experience no measurable growth issue. And among those who do, many cases are mild enough to require no additional intervention. Significant angular deformity or leg length difference that needs correction is rare.
Monitoring Growth After Surgery
If you’re still growing when you have ACL surgery, your surgeon will track your leg growth with regular check-ups and standing X-rays that image both legs in full length. This monitoring continues until you reach skeletal maturity, which is typically around age 18 to 19 for males and 17 to 18 for females. These follow-up images can catch any developing asymmetry early, when it’s easiest to address.
The practical takeaway: if your surgeon knows you’re still growing, they’ll choose a technique matched to your developmental stage and monitor you until your growth plates close. The combination of growth plate-aware surgical planning and consistent postoperative surveillance is what keeps the complication rate low. Most young athletes who tear their ACL go on to reach their full adult height without any issues from the surgery itself.