ACL Reconstruction Risks

When you have an injury to your ACL, your surgeon may recommend reconstruction to help relieve your pain, and restore function and stability to your knee. Most people who undergo an ACL reconstruction have a good outcome and do not have any complications however, any surgical procedure carries some risks. Some of these risks are seriousso, it is important to consider this with your surgeon before making the decision to proceed.

The most common risk associated with an ACL reconstruction is the risk of re-rupture. The chance of rupturing your “new” ACL is between 5-10%. This is higher if you return to impact or pivoting sports.

Other common risks (affecting 2-5% of patients) include:

  • Pain:
    The knee will be painful after the procedure. Pain killers will be given to reduce this as much as possible
  • Numbness:
    The skin around the knee or shin may be temporarily or more permanently numb due to damage of small nerves
  • Swelling/Haemarthrosis:
    This is a collection of fluid or blood in the knee joint. In most cases, the body will absorb the fluid itself. If the swelling becomes too large, the surgeon may feel an operation is necessary to drain
  • Stiffness:
    You may have difficulty in straightening your knee or squatting
  • Persistent Pain:
    Pain may persist after the procedure – despite successful surgery. A repeat arthroscopy or other knee operation may be required
  • Continued instability:
    Weakness and instability may occur despite adequate surgery

Rare risks (affecting less than 1% of patients) include:

  • Infection:
    The wound sites may become red, painful and hot. There may also be a discharge. These are signs of infection and can usually be treated by antibiotics. The infection may spread to the knee joint itself (requiring a washout) and removal of the graft. Infection may also spread to the blood (sepsis) requiring intravenous antibiotics
  • Deep Vein Thrombosis (DVT) or Pulmonary Embolism (PE):
    A DVT is a blood clot, usually in the calf/ leg. They can cause swelling and pain. Very rarely may they travel to the lungs (a PE) and cause a serious medical emergency
  • Damage to the Structures Within the Knee:
    This is rare, but may cause further damage and symptoms. This may need further treatment including operation. These include fracture, meniscal surgery or debridement of scar tissue
  • Abnormal Wound Healing:
    The scars may become thick, red and painful (keloid scar). This is more common in in patients of certain races. There may also be delayed healing or wound oozing
  • Compartment Syndrome:
    This is a build up of pressure within the lower leg and can cause nerve damage, blood vessel damage and muscle damage. If this occurs, an emergency operation will have to be performed to prevent death of tissue of the lower leg/foot
  • Osteoarthritis:
    This can be more common after knee injuries and operations