ACL reconstruction failure and revisions - a course by Frank Noyes, MD

This course by Frank Noyes MD covers the issue of why an anterior cruciate ligament (ACL) reconstruction might fail, and what options remain for a patient when this happens. If the procedure is re-done, then that is called a 'revision'. Dr Noyes is one of the world's foremost knee surgeons, researcher and author of hundreds of leading publications of many many topics to do with the knee.

Introduction to ACL reconstruction failure and revisions

• Definitions
• Relevant anatomy

What happens to an ACL graft after implantation?

• Revascularisation
• Remodelling
• Ligamentisation

Surgical choices for the initial ACL reconstruction

• Primary repair
• Extra-articular iliotibial band procedure
• Intra-articular reconstructions
  • autograft
  • allograft
  • synthetic graft
• Graft fixation

What constitutes ACL graft failure and how do you measure it?

• The patient's subjective evaluation of instability
• The surgeon's objective evaluation of laxity
  • Lachman test
  • Pivot shift test
  • KT 2000
• Confirmatory radiographic evaluation

Most common causes of ACL graft failure

ACL graft failure due to graft inadequacy

• Inappropriate use of primary repair
• Poor structural mechanical property of the graft prior to implantation
• Failure of ACL graft ligamentisation

ACL graft failure due to graft impingement

• Causes of graft impingement
• Cyclops lesion

ACL graft failure due to problems in graft tensioning and fixation

• Improper tensioning of graft prior to fixation
• Inadequate graft fixation

ACL graft failure due to failure to address associated instabilities

• Failure to adequately address the posterolateral corner
• The issue of simultaneous multiligament surgery
• Failure to stabilise existing meniscal damage

ACL graft failure due to inadequate rehabilitation programme

• Inappropriate speed of rehabilitation
• Failure to recognise early arthrofibrosis

ACL graft failure due to traumatic re-injury

• Injury related to proprioception deficit
• Injury related to muscle imbalance
• Injury related to returning to activities inappropriate for stage of healing

Compounding problems that must be addressed in revision ACL surgery

• Existing articular cartilage damage
• Damaged meniscus
• Bow legs (varus mal-alignment)
• Loss of secondary ligament restraints
• Weakened bone stock
• Pre-existing bony tunnels
• Notch problems
• Other problems

Graft options in revision ACL

• Allograft
• Ligament augmentation devices
• Synthetic grafts
• Autograft

Contraindications to ACL revision

• Partial function of a prior ACL reconstruction
• No symptoms (pain,swelling, giving way) in a patient who does not participate in strenuous or high risk activities
• Prior joint infection
• Obesity (body mass index >30)
• Bowed legs where the patient refuses to undergo a high tibial osteotomy before or with the ACL revision reconstruction
• Severe muscle atrophy (wasting)
• Poor patient motivation or expectations
• Knee arthrofibrosis
• Deficiency of the posterolateral structures where the patient refuses to undergo an associated posterolateral reconstruction with the ACL revision.

What can one expect after ACL revision?

• Outcomes