The ankle reflex predicts outcome after lumbar disc surgery?

An ankle reflex is a test of mainly the first sacral nerve root, or S1 as an abbreviation. When S1 is working normally, a small strike of the achilles tendon , also called calcaneal tendon, with a tendon hammer causes the muscle attached to the tendon, gastrocnemius, to contract, which in turn causes the foot to flex downward.

The ankle reflex is performed as part of a neurologic examination of the legs, which is part of the investigation of sciatica. The ankle reflex is often not quite normal when the lowest lumbar disc, or L5/S1 disc, is compressing the S1 nerve root. People often ask whether this is relevant and, according to a group of spinal surgeons from Iran, it has a predictive influence on surgical outcome. They found that although roughly 90% of people who underwent L5/S1 discectomy surgery had improved outcomes, the results were not quite as good in those who did not have a normal ankle reflex before their surgery. The group also found that the weaker ankle reflexes tended to be associated with more sciatica pain prior to surgery.

Is this recent publication relevant to us? Probably. If you ever find yourself discussing the prospect of having a lumbar discectomy with a spinal surgeon, then you will want to know the likelihood of having a good outcome from the operation. One question ought to be whether your ankle reflex is normal, as this will help to predict your surgical outcome.

You can download the free publication on the ankle reflex here.