Surgical techniques are continually evolving and improving in the quest for medical improvement as are surgical indications for specific surgeries. ACL reconstruction surgery is no exception to this rule.
ACL reconstruction is typically an excellent operation and deals with the intra-articular (inside the joint) aspect of an ACL rupture however extra-articular (outside the joint) structures are frequently injured when you tear your ACL. It makes sense that addressing only the intra-articular and NOT these extra-articular structures such has having an extra-articular tenodesis may leave the knee somewhat unstable in some of the population.
When you have a tear to the ACL frequently the anterolateral capulse of the knee is also injured, this capsular avulsion is called a Segond fracture. This lesion has been shown to be present in the majority of acute ACL injuries and is associated with significantly increased rotational knee laxity.
Anatomical studies have suggested
- There is a ligament which originates from the lateral femoral condyle and inserts on to the anterolateral tibial plateau.
- Over time this ligament can stretch out and cause more anterior laxity in the already ACL deficient knee.
It Just Makes Sense
If both intra and extra-articular structures are injured then repairing only one of them may well leave the knee somewhat unstable.
- Reconstruction outside the knee it is better at controlling tibial rotation and decreases the stress on the intra-articular reconstruction by about 40%.
- This could be especially useful in cases of revision ACL reconstruction.
The anatomy and biomechanics of the anterolateral structures of the knee remain largely undetermined, as it stands extra-articular tenodesis (surgery for these extra-articular structures) may well play a more involved role in the future of ACL surgery and the management of ACL ruptures.
- The challenge becomes for surgeons to work out which patients require a traditional athoroscopic ACL reconstruction and which patients may require an extra-articular tenodesis.
- Unfortunately we currently lack the practical clinical tools to objectively assess knee rotational laxities, MRI scanning and clinical examination are not yet accurate enough to help us with decision making.
There is concincing clinical evidence that lateral extra- articular augmentation should be used in a revision reconstruction where no clear reason for failure of the previous graft is seen. So what is the future involvement of extra-articular tenodesis? Sadly it is a case of watch this space.
Disclaimer: Sydney Physio Clinic does not endorse any treatments, procedures, products mentioned. This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific orthopaedic advice or assistance on Extra-Articular Tenodesis should consult his or her orthopaedic surgeon, general practitioner or physiotherapist.
Note: Content for this blog was taken and adapted from the “Medical Observer” specifically an article titled “Not all knee surgeries are the same”