Thomas Grove, DO
We saw a patient who underwent back surgery. The procedure did not provide significant relief. Eventually the patient’s situation improved through months of physical therapy instead. However, a complication arose after the operation: the patient developed a condition known as foot drop, a fairly common occurrence following such surgeries.
Having spent extensive time in operating rooms, I have learned that surgical positioning can sometimes lead to nerve compression. In this case, a nerve located behind the shin bone was pinched during the operation, even though the surgery was performed on the back. Surgical teams often place patients in various positions to access the area being operated on, but these positions can inadvertently compress nerves.
Whenever I encounter a case of foot drop, I consider whether the cause may originate from the back—specifically, whether a nerve was pinched or damaged during the procedure. It’s also possible that the compression was simply due to the patient’s position during surgery. This is analogous to waking up with a limb that feels numb after sleeping in an awkward position; the sensation results from nerve compression, and depending on the amount of pressure and duration, the nerve may not fully recover on its own.
This situation is known as peripheral nerve entrapment, where a nerve away from the spinal cord becomes pinched and produces symptoms such as numbness, tingling, or weakness. In this particular case, the patient’s foot drop prevented them from lifting their toes toward their head, making walking difficult and leading to frequent trips and falls. The patient sought our help as a last resort, believing the issue was simply a damaged nerve from surgery.
After a thorough physical examination and a dynamic ultrasound scan, we discovered the exact location where the nerve was compressed. This was a pivotal moment, as it allowed us to identify the source of the patient’s symptoms. The treatment applied was a nerve hydrodissection, where fluid is injected through a needle to decompress the nerve. Normally, a nerve should appear round, with bundles of wires insulated by fat, Schwann cells, and myelin sheath. When compressed and flattened, nerve signals cannot propagate effectively, resulting in symptoms like numbness, tingling, and weakness.
The nerve hydrodissection procedure is relatively advanced and new, made possible by improvements in ultrasound technology that allow us to visualize nerves more clearly. This highlights the importance of musculoskeletal ultrasound training to diagnose these conditions accurately.
In this case, the patient noticed significant improvement within a week or two after treatment, regaining some strength in their affected limb. This was a successful resolution for someone considering multiple back surgeries, as the underlying issue was actually a basic peripheral nerve entrapment.
Nerve entrapments can occur throughout the body, affecting various nerves and locations. One of the most well-known examples is carpal tunnel syndrome, which involves the median nerve at the wrist. Although the specific nerve and affected area may differ, the underlying principles for diagnosis and treatment remain consistent.