The anatomy of the human knee has been studied for centuries now so it was quite a revelation at the end of 2013 that researchers had identified a ‘new’ knee ligament, the anterolateral ligament, or ALL.
It is not technically new (its always been there in our knee joints). In fact, many surgeons over the years have described a similar structure. But it was only when this anterolateral part of the knee was studied again using modern scanning techniques and careful micro dissections was the ALL described in detail.
What does the ALL do?
This tough but thin strip of connective tissue joins the thigh bone and shin bone along the outer surface of the knee joint. It is crucial for the stability of the joint during twisting movements, such as turning to put something in the boot of your car.
If your ALL tears, you can experience the embarrassment of your knee giving way completely at such moments.
Why reconstruct the ALL if it tears?
Although only discovered recently, Mr Adrian Wilson, Consultant Orthopaedic Surgeon at The Berkshire Independent Hospital and a leading knee specialist, has already developed an operation to reconstruct a damaged ALL.
“Quite often, people who have a knee injury and tear their anterior cruciate ligament, ACL, find that their knee remains unstable after the ACL is repaired or reconstructed. This is because we didn’t know it existed, let alone that it was torn. Now that the ALL has been found, we can check it is intact and, if not, replace it with tissue from the hamstring at the top of the thigh,” explains Mr Wilson.
ALL reconstruction surgery
Although this is sometimes described as ALL repair, it is not actually a repair. The thin tissue disintegrates when it tears and its function needs to be taken over by connective tissue from the hamstring.
Mr Wilson worked with the researchers from Belgium who discovered the ALL, Dr Steven Claes and Professor Johan Bellemans, to develop a keyhole surgery technique to replace the damaged tissue.
The operation takes about 20 minutes, and is usually performed during a standard ACL reconstruction. Only two small incisions are made in the knee; the 10cm long piece of hamstring is put into place and fixed securely.
The 50 or so patients who have had a combined ACL and ALL reconstruction have been very satisfied with the results. To date, after two-years of follow up, all of Mr Wilson’s patients have made an excellent recovery, with no failures. Other surgeons who carry out ALL reconstruction in conjunction with ACL surgery are getting similar improvements in their results.
“The problem of persistent knee joint failure after an ACL repair or replacement does not occur in these patients so we are confident we have more understanding of what the ALL does and how repairing it can restore a higher level of function to the knee joint,” explains Mr Wilson.
Who can benefit?
ALL reconstruction should be considered in patients who:
Have suffered a sporting injury with knee ligament damage Require a revision of their ACL reconstruction due to ongoing problems Have rotatory laxity of the knee joint, whether due to injury or not
For more information about ALL repair contact The Berkshire Independent Hospital on 0118 902 8114.