Failed Back Surgery Syndrome (FBSS)
In a sense this diagnosis is self-explanatory. Patients have failed to have an adequate response to their back surgeries. In many cases these patients may have more pain than prior to intervention.
There are a number of reasons why back surgery may fail. In some cases the surgery may have been technically good but the wrong diagnosis was made, resulting in no benefit being attained. Alternatively, there may be complications from the surgery itself or worsening of the underlying pathology.
While discectomy for radicular pain has a very high rate of success (around 90%) other more complex surgeries for back pain do not achieve the same outcomes.
Spinal fusions in particular are more controversial. There is data from Rick Derby in California that demonstrates that there may be varied outcomes from different types of fusions relating to the sensitivity of the disc during provocative discography. Discs that are markedly painful at low pressure discography may have poorer surgical outcomes with posterior instrumentation (screws and plates) compared to disc removal and interbody fusion.
Often when one of the instrumentation procedures has failed there is consideration for removal of the metal apparatus, however, there is limited evidence to support better outcomes with removal of screws and rods in the failed back surgery patient.
Sometimes the body’s reactions to surgery, including scar formation traversing the nerve roots, can cause persisting radicular or neuropathic type pain. Neuropathic pain may respond to some medications (especially anti-epileptics and tri-cyclic anti-depressants), radicular pain can be controlled occasionally by a series of transforaminal epidurals.