Will Individuals Who Have Had Mild Bulbar Polio with No Functional Limb Impacts Develop Post-Polio Limb Weakness?

Question: Will individuals who had mild bulbar polio with no functional limb impacts develop post-polio limb weakness? Is anything known about extra risks to recovery from major orthopedic surgery such as knee replacement to post-polio individuals?

Marny Eulberg, MD: It is possible that persons who had mild bulbar polio but no functional limb weakness could develop post-polio limb weakness over time because they may also have had some mild deficits in the nerves going to muscles in their limbs. Generally, there is no noticeable weakness until a muscle has lost about 50% of its motor nerve supply. So, if a muscle lost 45% of its motor nerve supply, there would be no noticeable weakness but if the effects of aging and the normal loss of motor units now crosses the 50% threshold, they may for the first time notice some weakness that can SLOWLY progress.

The good news is that if you, like most polio survivors in the developed world, are in your 70s or greater, it is likely that if you have not developed PPS by now, you have a good chance of not developing any significant limb weakness related to your prior polio.

As for your question about major orthopedic surgery such as a knee replacement in post-polio individuals, it depends a lot on whether the proposed surgery is on a limb that has muscle weakness from polio versus a “polio-unaffected limb.” In my experience, polio survivors do as well as people who never had polio if the joint replacement is on the polio-non-affected limb (and that is also the one that most often wears out because of necessary overuse). Often, if a joint is on the polio-affected limb, especially if severe, the surgeon will refuse to perform surgery on that limb even though it might be possible, as long as the person and the surgeon accept that that limb will need to be braced after the surgery.

If you were asking for yourself, from what you are telling us in your submission, you likely would do well after a knee joint replacement. It would be recommended that any lower extremity surgery be done under spinal or local anesthesia because of your bulbar involvement, but most surgeons/hospitals recommend those forms of regional anesthesia rather than general anesthesia for nearly all of their hip or knee joint replacement patients.

Post-Polio Health (Vol. 39, No. 4, Fall 2023)