Graft options
| Graft | Advantages | Considerations |
|---|---|---|
| Hamstring (most common) | Smaller scar, less anterior knee pain, faster early recovery | Slightly higher re-injury risk in young high-demand athletes |
| Patellar tendon | Larger, more robust graft; lower re-injury risk | Longer recovery; potential for anterior knee pain |
| Allograft (donor tissue) | No donor-site morbidity; useful in revision and multi-ligament surgery | Slower graft incorporation; not typically used in young athletes |
Surgical technique
The operation is performed arthroscopically. Bone tunnels are drilled through the tibia and femur along the path of the original ACL. The graft is threaded through these tunnels and fixed using endo-buttons, screws or similar devices.
Pre-surgery preparation
The knee should regain full range of motion and have only minimal swelling before surgery. Pre-operative physiotherapy ("pre-hab") significantly improves outcomes.
Graft healing
The graft takes around 8 weeks to bond into the bone tunnels and a further several months to fully mature into ligament-like tissue. Full strength is regained at 12–18 months.
Phased recovery timeline
- 0–2 weeks: protected weight-bearing, range of motion, swelling control.
- 2–6 weeks: increasing weight-bearing, quadriceps strengthening.
- 6–12 weeks: gym work, gentle running once strength benchmarks are met.
- 3–6 months: running, agility, sport-specific drills.
- 9–12 months: return to twisting and pivoting sports.
- 12–18 months: final return of strength and confidence.
Driving and work
Driving is usually safe between 2 and 6 weeks depending on which side was operated on, vehicle type and confidence with emergency braking. Office-based work is often possible within 1–2 weeks. Manual or labour-intensive jobs take longer.
Re-rupture rate
The re-rupture rate after ACL reconstruction is approximately 5%. Risk factors include young age, return to high-pivot sport, contralateral knee laxity and poor graft technique.