A torn Achilles tendon is repaired by surgically stitching the two torn ends back together, typically through an incision on the back of the lower leg. The procedure is ideally performed within two weeks of the injury, and full recovery takes 6 to 9 months. While non-surgical treatment with structured rehabilitation is an option for some patients, surgery remains the most common approach, especially for active individuals who want to return to sports.
Open Repair vs. Minimally Invasive Repair
There are two main surgical approaches. In a traditional open repair, the surgeon makes an incision several centimeters long directly over the rupture site on the back of the ankle. This gives full visibility of the torn tendon ends, making it easier to align and stitch them precisely. The tradeoff is a larger wound, which carries a higher risk of infection and slower skin healing.
Minimally invasive techniques use smaller incisions. A mini-open approach, for example, uses a 2 to 3 centimeter incision at the rupture site with tiny 5-millimeter incisions on either side. This still allows the surgeon to see the repair directly, which helps protect the sural nerve, a sensory nerve running along the outer edge of the foot and ankle. Percutaneous (through-the-skin) repair uses even smaller puncture wounds and specialized instruments to pass stitches through the tendon without opening the skin widely. It heals faster cosmetically but is more technically demanding and carries a slightly higher risk of nerve injury because the surgeon is working without full visual control.
What Happens During the Procedure
Most Achilles repairs are done under spinal anesthesia, which numbs the body from the waist down. A newer option is a nerve block behind the knee, which numbs only the lower leg while preserving movement in the rest of the limb. This approach extends pain relief into the hours after surgery and tends to cause fewer side effects than spinal anesthesia.
You’re typically positioned face-down on the operating table. Once the surgeon reaches the torn tendon, the frayed ends are cleaned up and brought back together. Strong sutures are woven through both ends in a specific locking pattern to hold the repair under tension while it heals. The most common stitching patterns are the Krackow and Bunnell techniques, both of which loop through the tendon tissue in a way that prevents the sutures from pulling out. In cadaver testing, both techniques showed only a 16.7% failure rate under extreme loads, significantly outperforming simpler stitching methods. The repaired tendon is set at the right tension so the ankle rests in a slightly toes-down position, and the skin is closed.
Repairing Chronic or Large-Gap Tears
When an Achilles rupture goes untreated for weeks or months, the torn ends retract and scar tissue fills the gap. A straightforward stitch-together repair is no longer possible if the gap exceeds 1 to 2 centimeters. In these cases, surgeons typically perform a tendon transfer, borrowing a nearby tendon to bridge the defect. The most commonly used donor is the tendon of the flexor hallucis longus, a muscle that runs along the back of the lower leg and normally helps curl the big toe. This tendon is rerouted into the heel bone to take over the pushing-off function of the Achilles. Losing it causes minimal impact on toe strength for most people, and the procedure has a strong track record for restoring walking and moderate activity.
Surgery vs. Non-Surgical Treatment
Not every torn Achilles requires an operation. Conservative treatment involves immobilizing the ankle in a boot with the foot angled downward, allowing the torn ends to heal on their own, followed by a structured rehabilitation program. The key question is re-rupture risk.
A large meta-analysis of over 1,100 patients found that surgery reduces the overall re-rupture rate by about 62% compared to conservative treatment. However, when non-surgical patients followed an accelerated functional rehabilitation protocol (early controlled movement rather than rigid casting), the re-rupture rates between the two groups were statistically equal. This means the rehabilitation program matters enormously. If you have access to a structured, early-movement rehab protocol, non-surgical treatment can achieve similar outcomes. Without one, surgery offers a meaningful protective advantage.
Risks and Complications
The most common surgical complications involve the wound itself. Open repair carries a notable risk of wound breakdown and infection because the skin over the Achilles has relatively poor blood supply. Minimally invasive techniques reduce this risk by using smaller incisions.
Sural nerve injury is the other significant concern. This nerve runs close to the Achilles tendon, and instruments or sutures can damage it during repair. In cadaver studies using one popular minimally invasive device, the nerve was hit in 28% of specimens. Damage to this nerve causes numbness or tingling along the outer edge of the foot. It’s rarely debilitating but can be permanent. Mini-open techniques, which allow the surgeon to see and protect the nerve directly, appear to lower this risk.
Re-rupture after surgical repair is uncommon. One long-term study reported a re-rupture rate of just 1%.
Recovery Timeline Week by Week
The first two weeks after surgery are a protection phase. You’ll be non-weight-bearing, using crutches, with the ankle immobilized. Even during this early stage, gentle exercises like toe taps, toe spreading, and ankle circles help maintain circulation and prevent stiffness in the surrounding muscles.
At week 2, you transition into a walking boot and begin putting weight on the leg with crutch support. Most people ditch the crutches by week 4. The boot stays on, and you start doing weight shifts and light loading exercises to begin rebuilding the connection between your calf muscles and the healing tendon.
By week 8, the boot comes off entirely. This is when standing heel raises begin, initially with both legs sharing the load. Balance training on unstable surfaces starts around the same time. Weeks 8 through 12 focus heavily on rebuilding calf strength and ankle stability.
After week 12, the focus shifts to functional training. Running and jumping typically start between weeks 12 and 16 for those progressing well. Return to sport generally falls in the 6 to 9 month window, though higher-impact sports like basketball or soccer may push closer to 9 to 12 months.
Long-Term Strength and Function
Even with successful surgery and diligent rehab, the repaired leg rarely returns to 100% of its pre-injury strength. At one year after surgery, most people still have a 10 to 30% deficit in calf pushing power compared to the uninjured side. Heel-rise endurance (how many times you can go up on your toes) typically remains 20 to 30% lower for over a year. The calf muscle itself undergoes significant shrinkage after the injury and repair, and rebuilding that volume takes sustained effort.
These deficits aren’t just about muscle weakness. The repaired tendon can end up slightly longer than the original, which changes the mechanical advantage of the calf muscle and makes it particularly weak at the end of its range, right when you’re pushing off during walking or running. Long-term studies show that some calf performance deficits persist as far out as 7 years after the injury.
Despite these measurable differences, most people function well. About 81% of surgical patients return to their previous level of activity, though roughly 16% experience some lasting reduction in ankle range of motion. For recreational athletes, the strength gap is often unnoticeable in daily life but becomes apparent during high-demand activities like sprinting or jumping.