We Work with Spine Surgeons
How can peripheral nerve surgery benefit the spine surgeon? – By providing effective solutions for:
- Radiating or “radicular-like” pain or paresthesias which persist in the upper extremities following cervical spine surgery.
- “Sciatica” or “radicular-like” pain or paresthesias which persist in lower lower extremities following lumbosacral spine surgery.
- Radiating, “sciatica,” or “radicular-like” pain or paresthesias in upper or lower extremities for which MRI imaging provides no clear etiology at the spine level.
- Persistent weakness after trauma or spine surgery – foot drop, wrist drop, sciatic or femoral nerve palsies, neurogenic thoracic outlet syndrome, piriformis syndrome, etc.)
- Certain types of lumbosacral “back pain” that persists after spine pathology has been adequately addressed (superior and middle cluneal compression/injury, piriformis syndrome, etc.)
Bottom Line – Pain, motor weakness, and paresthesias of neurogenic origin can only come from one of two places, either the central nervous system or the peripheral nervous system. Once the central nervous system has been ruled out, it’s a peripheral nerve problem until proven otherwise. A significant amount of pathology that has traditionally been viewed as “coming from the spine,” particularly the low back, actually involves the peripheral nervous system.
Generally speaking, the default position of most physicians is to consider the presence of radiating pain, motor weakness, or paresthesias in the shoulder/pelvic girdles and upper/lower extremities to be due to “a spine problem,” period. This view has thrived mainly due to a widespread lack of knowledge regarding detailed peripheral nerve anatomy and how peripheral nerve problems typically present. While CT and MRI imaging can render detailed views of the skull, brain, spine, spinal cord, and nerve roots, allowing for close examination of these structures, no such corollary exists for interrogating the peripheral nervous system. Practically speaking, peripheral nerves are essentially “invisible” to the same imaging systems that give such detailed information regarding the components of the central nervous system. In addition, although regularly utilized, electromyography and nerve conduction studies tend to add little diagnostic information in the setting of complex peripheral nerve pathology.
Compounding these issues is the fact that overwhelmingly, the main byproduct of peripheral nerve pathology is essentially chronic pain. The history of pain management has, to a greater or lesser degree, been the story of “one size fits all.” While pain medication has been very successful in the area of treating acute pain, for many patients suffering with chronic pain, it has failed miserably. Despite this reality, a dogged persistence in doling out narcotics, primarily for lack of a better option, has remained the approach for treating the chronic pain patient.
General physician ignorance regarding peripheral nerve anatomy, the lack of reliable techniques to obtain “objective” data about peripheral nerves, and the traditional focus on managing symptoms, the pain, rather than trying to discover and eliminate the source, the pain generator, has essentially resulted in the peripheral nervous system assuming the role of a medical “black box.” The key to stripping the shroud of mystery away from the peripheral nervous system is to have an intimate knowledge of peripheral nerve anatomy. This is really the “Rosetta Stone” that unlocks the secrets of many chronic pain problems which have traditionally been considered untreatable.
For the spine surgeon in particular, trying to diagnose the source of pain in a patient whose primary issue involves upper or lower extremity pain, by relying solely on MRI imaging or physical exam maneuvers designed to unmask or confirm a radiculopathy, without having a clear picture of the status of the peripheral nervous system, certainly increases the risk of error. Very often a patient may have a lesion at the spine level coexisting with one or more peripheral nerve compressions or peripheral nerve damage. Operating on the spine will likely resolve the spine issue but may leave the patient unsatisfied if the peripheral pain remains. In situations where the peripheral pain is not clearly due to a radiculopathy, having the patient undergo a comprehensive peripheral nerve evaluation can set realistic expectations for both the spine surgeon and patient in terms of what’s achievable with spine surgery alone. Likewise, if a patient who has already undergone spine surgery and demonstrates no further compressive lesions at the spine level, continues to experience peripheral symptoms, then the spine surgeon can discuss the possibility of ongoing peripheral nerve pathology and refer the patient for consultation. This tends to increase patient satisfaction while at the same time making life easier on the spine surgeon.
While peripheral nerve surgery is not a substitute for traditional spine surgery and can’t address pathology involving the bony spine, nerve roots or spinal cord, one of the newer facets of peripheral nerve surgery is geared towards addressing peripheral nerve pathology which can closely mimic the same kind of low back or pelvic pain that comes from true spine pathology. Sometimes these nerve can be the primary cause of the pain and sometimes they become an issue following a primary spine procedure. These nerves include the dorsal rami of all the intervertebral nerves, in particular the superior cluneal nerve that are highly vulnerable to developing compression neuropathies where they pierce the thick lumbosacral fascia at the level of the posterior iliac crest. Middle and inferior cluneal, as well as the lateral branch of T12 or the iliohypogastric nerve are also potential pain generators that can mimic low back pain when compressed or damaged. Maybe one of the most under diagnosed sources of “sciatica” pain is compression of the sciatic nerve at the level of the piriformis muscle (piriformis syndrome). This peripheral nerve compression can cause anything from isolated deep posterior buttock pain to pain which can perfectly mimic a lumbosacral radiculopathy. Piriformis syndrome is a frequent confounder for spine surgeons who promised their patient that the lumbar spine fusion would completely resolve the problem, only to have to face an irate patient who is still experiencing severe pain in a lower extremity despite having undergone back surgery.
For the spine surgeon, keeping the possibility of a peripheral nerve lesion at the forefront of the differential diagnosis, especially in patients with extremity pain or “atypical” pain symptoms from a spine standpoint, is always a good idea. In reality, any patient who has undergone the prescribed course of treatment or surgery from a spine approach, or who clearly has no identifiable lesion involving the spine, but who still experiences extremity or lumbosacral low back pain is a good candidate for a peripheral nerve evaluation.
We Work with Orthopedic Surgeons
How can peripheral nerve surgery benefit the orthopedic surgeon? – By providing effective solutions for:
- Chronic pain after total joint arthroplasty
- Chronic pain after nonsurgical orthopedic trauma
- Chronic pain after orthopedic trauma requiring surgical intervention
- Chronic pain after elective orthopedic surgery
- Many types of chronic pain which may resemble a specific orthopedic problem but for which no “orthopedic etiology” can be identified
- Persistent weakness after orthopedic trauma or surgery – foot drop, wrist drop, sciatic or femoral nerve palsy, neurogenic thoracic outlet syndrome, etc.)
Bottom Line – patients who continue to experience persistent pain, paresthesias, or weakness after orthopedic trauma or surgery should be considered to have an undiagnosed peripheral nerve injury until proven otherwise.
The subspecialty field of peripheral nerve surgery geared towards eliminating pain of nerve origin is without a doubt the most significant advancement in treating chronic pain since the discovery of the opium poppy. Despite the advances of modern medicine, patients who continue to experience debilitating pain after surgery or traumatic injury are still often left with treatment options that would have been familiar to the ancient Egyptians more than 5 millennia ago – opium based pain medication. In the 21st century, we can now replace painful arthritic knee joints with engineering marvels made of metal alloys, plastic, and ceramic components. Ironically, if the patient still experiences chronic debilitating “knee pain” after a total knee arthroplasty, they invariably end up being treated with technology that’s essentially 5,000 years old.
This relatively new field of peripheral nerve surgery represents a “hand in glove” symbiosis which can provide solutions for some of the most difficult problems the orthopedic surgeon faces in trying to diagnosis and treat disorders of the musculoskeletal system. One important concept to understand is that the type of injury mechanisms that produces orthopedic injuries, as well as the type of surgery that is often required to address orthopedic pathology puts patients at significant risk of sustaining concomitant injuries to the peripheral nervous system. Peripheral nerve’s are the musculoskeletal systems’ “silent partner,” if you will. In the setting of acute trauma, injuries to bones, ligaments and tendons are readily diagnosed with the latest imaging techniques. These serious injuries can then be addressed in the appropriate manner, sometimes with conservative treatment, but very frequently requiring surgical intervention. Unless a peripheral nerve injury involves major damage to an important motor nerve, the pain and weakness that accompanies peripheral nerve pathology will usually be “masked” or “blend in” with the rest of the pain generated by the orthopedic trauma. This is equally applicable to nerve damage resulting from elective orthopedic procedures. In the case of nerve compression, it may takes weeks or months for the patient to even start to experience pain. Because peripheral nerves are not imaged well with CT scans or MRIs, and because orthopedic physical examination is not designed to pick up most peripheral nerve injuries, they will often be missed in the acute setting and remain undiagnosed over the long term.
For most orthopedic procedures, wether it be an IM nail for a long bone fracture or a total joint arthroplasty, the surgeon usually has a fairly good idea of the timeframe required for recovery. So what does an orthopedic surgeon do when the patient starts to fall off the “recovery curve,” due to acute pain or weakness that persists long enough to become “chronic?” There are the usual steps of ruling out infection, hardware or implant defects, and making sure that the procedure was performed correctly, but when all those boxes have been checked what options are left? Returning to the knee replacement example above, what is an orthopedic surgeon to do in the case of the patient with a “perfect” total knee arthroplasty (TKA) and no post-operative complications, who continues to complain about debilitating knee pain? In an article published in the journal “Pain” in 2011, 15% of patients reported experiencing “severe-extreme” persistent pain 3 to 4 years following a total knee arthroplasty. Approximately 700,000 total knee arthroplasties are performed annually in the US. Using the “15%” figure, this translates to over 100,000 people a year continuing to experience debilitating knee pain even after the pathologic joint has been completely removed! This is a problem that is widely recognized in the orthopedic community, but for which no one has any diagnosis or solution.
The answer to the scenario of the TKA patient with no post-operative complications but continued, debilitating knee pain is that the orthopedic surgeon is no longer dealing with an orthopedic problem. He is now trying to solve a peripheral nerve puzzle. It’s like expecting the carpenter to fix an electrical issue!
The reason patients have persistent knee pain after TKA is that in most cases, the original sensory nerves to the knee joint, as well as the sensory nerves innervating the soft tissue envelope around the knee have all be left behind. Due to damage or entrapment in scar tissue, these nerves are now simply serving as chronic pain generators, sending constant pain signals to the brain. In these situations, it doesn’t matter how many additional orthopedic procedures the patient undergoes, the pain will never get better. In fact, at this stage, additional surgery aimed at solving a nonexistent orthopedic problem will often compound the situation leading to even more morbidity for the patient. Post-TKA neurogenic pain is often misdiagnosed as some type of “unrecognized or under treated” preexisting pathology, a problem with the implant itself, or “chronic infection,” often leading to additional, unnecessary surgery for the patient.
From the orthopedic surgeon’s perspective, peripheral nerve surgery provides an excellent alternative to consigning their “chronic pain” patients to languish forever in the pain management setting, by offering definitive, permanent relief of chronic neurogenic pain in most cases. Remember, for patients who develop chronic pain following trauma or surgery, and especially for patients with pain for which imaging provides no clear orthopedic etiology, keep the possibility of a peripheral nerve problem near the top of your differential diagnosis list.