Wound or intra-articular infection (<1%).

Bleeding - this is common, but usually not significant.

Nerve or vascular injury : usually this is only numbness around the scars, but rarely can involve the major nerves that control the lower leg, or the vessel that supplies blood to the lower leg. Injury to either of these structures results in permanent disability.

Chondromalacia patella : softening of the articular cartilage of the kneecap,more common after patellar tendon graft.

Patellar fracture or patellar tendinitis -only if we use the patellar tendon graf.

Loss of bending strength (<8% total strength) in the case that we use the hamstrings tendons as a graft.

Loss of quadriceps strength - particularly after use of the patellar tendon graft.

Breakage of the surgical instruments inside the knee: rare.

Graft failure: 5 - 10% at 10 years.

Knee stiffness can be mild during the rehab, or sometimes serious with permanent loss of knee motion.

Deep venous thrombosis: blood clot in the leg.

Anesthetic complications.

The goal of the surgery is to get a stable knee, but we can't get rid of the degenerative wearing changes caused by the previous instability.