Here's an overview of the surgical interventions beyond drug injections that let us provide better, faster, cheaper treatment for back pain.

Vertebroplasty and kyphoplasty
These 2 procedures are designed to treat spinal compression fractures, which commonly result from osteoporosis. In about 65% of the 700,000 compression fractures reported in the United States each year, these procedures provide the patient with excellent pain relief and spine stability.

Vertebroplasty involves placing a cannulated trochar through the pedicle of a compression fracture into the vertebral body. This may be done using a uni-pedicular or bi-pedicular technique. In either case, once the trochar has been positioned under fluoroscopic guidance, a methyl methacrylate cement mixed with radiopaque contrast is injected into the fracture. Fluoroscopic imaging assists in ensuring the cement adequately fills the fracture and doesn't leak into the spinal canal.

Kyphoplasty also injects cement into a compression fracture, but it employs a balloon catheter before the injection to allow the reduction of the fracture through the restoration of vertebral body height. The description for the kyphoplasty code (now entitled vertebral augmentation) has changed to describe a procedure that creates a void within the vertebral body by one of several mechanical means. This allows the use of alternative and, in many cases, more cost-effective devices in creating the cavity before the cement injection.

Each procedure has its pros and cons. In most, if not all, cases, vertebroplasty can be performed with conscious sedation and in a short period of time. Kyphoplasty, on the other hand, often requires general anesthesia and takes longer to complete. But it can reduce acute compression fractures and allows the injection of cement under low pressure.

Spinal cord & peripheral nerve stimulation
In spinal cord stimulation (SCS), leads are implanted in a patient's spinal canal to electrically stimulate the spinal cord and relieve lower back and, often more effectively, leg pain. This procedure is indicated for cases of failed back surgery syndrome, complex regional pain syndrome and radiculopathy that isn't amenable to surgery.

SCS can be performed in either of 2 ways. In one technique, long, thin catheter leads containing stimulating electrodes are percutaneously implanted through a needle into the epidural space along the posterior aspect of the spinal cord. In the other, paddle leads impregnated with the electrodes are implanted into the epidural space by way of a surgical laminotomy. Both techniques require the surgical implantation of a lithium battery to power the leads. This hardware is typically placed in a posterior flank or upper buttock subcutaneous pocket, with the leads tunneled to the pocket and attached to the battery. The advantage of the percutaneous approach is that patients can receive conscious sedation or monitored anesthesia care (MAC), rather than the general anesthesia necessary for the laminotomy method.

Peripheral nerve stimulation (PNS) uses the same technology and equipment as SCS, but the targeted structures are the peripheral nerves rather than the spinal cord. PNS is indicated for the treatment of lower back pain, but not leg pain. PNS's implantation techniques differ in the placement locations of the leads, but are identical with regard to the battery and lead tunneling.

While no one understands entirely how SCS and PNS work, the prevailing theory suggests a neuromodulating effect on the transmission of pain. Electrical stimulation of the spinal cord or peripheral nerves produces vibration signals that travel to the brain at 60 meters per second, beating the slower pain signals traveling about 1 meter per second. As a result, the brain is bombarded by the vibration sensations, which leave no room for the pain signals to have any impact. All patients undergo a 3- to 5-day temporary percutaneous trial first to assess whether these modalities will effectively treat their pain before they commit to an implant.

Medicare's reimbursement rates for stimulator procedures will limit the type of battery that you can implant in an ASC. Given the expense of the rechargeable and the higher-end non-rechargeable batteries, and Medicare's fixed facility fees, only the least expensive non-rechargeable battery is feasible to implant in an ASC.

Intrathecal drug delivery pumps
When all other means of conservation care have failed to provide a patient with relief from chronic malignant or non-malignant pain or reduced the tone of his spasticity, intrathecal drug delivery pumps may be an option.

Intrathecal infusion bypasses the blood-brain barrier, enabling direct access to the brain and spinal cord neuroceptors. Less medication is required to obtain the desired result, so there's less risk of side effects from the medications. The FDA has approved only morphine, baclofen and ziconotide (an N-type calcium channel blocker) for infusion into human spinal fluid, but several other medications have been used off-label in the pumps.

An intrathecal pump system consists of an intrathecal catheter and a programmable (computerized, battery-operated devices that can dispense medication at different rates throughout the day, and can deliver a bolus) or non-programmable (different volumes and different fixed rates) pump.

Patients can be administered MAC or general anesthesia for the procedure, depending on their status. The catheter is inserted into the intrathecal space by way of a 14-gauge needle. The pump is placed in a subcutaneous abdominal pocket. The catheter is tunneled to the pocket and connected to the pump, which doses medication into the intrathecal space. As with stimulator implants, perform temporary trials on all patients in the weeks before surgery to ascertain the effect the pumps will have on their pain before they're implanted.

Percutaneous discectomy
The treatment of a herniated lumbar disc accompanied by radiculopathy once required a laminectomy, with its large incision, stripping of spinal muscles and breaking of lamina to reach the disc. With percutaneous discectomy, however, ruptured, protruding or otherwise degenerated discs can be decompressed through a small incision, with little scarring and with no musculoskeletal damage.

This procedure is most effective when used to treat smaller, contained disc protrusions. It's easily performed in the ASC, with patients under conscious sedation and local anesthetics, and with surgeons guided by fluoroscopic imaging. Device manufacturers offer many products designed to probe the spine, remove part of the disc's nuclear material and suction it out to shrink the disc's volume and relieve the pressure of its mass on nerves.

Putting it all together
It's estimated that 90% of Americans will suffer from lower back pain during their lifetimes. The feasibility of performing these procedures on Medicare patients depends on the cost of the implants (for SCS, PNS and intrathecal drug delivery, where the hardware can total to tens of thousands of dollars) and disposables (for percutaneous discectomy, where the necessary supplies can cost $200). Some commercial insurers won't reimburse for peripheral nerve stimulator or percutaneous discectomy procedures, even though they'll cover spinal cord stimulator and intrathecal pump procedures.