What Is A Hardware Blocks?

Spinal pain is one of the most common reasons why people seek treatment from their physicians. With the aging population, it is expected that the number of people suffering from spinal pain will increase dramatically throughout the coming years. When a patient’s spinal pain does not improve with conservative treatment options, including non-steroidal anti-inflammatory medication, physical therapy, massage therapy, acupuncture, spinal manipulation, and nerve blocks, among others, a patient’s physician may recommend spinal surgery.

In the United States, it is estimated that 300,000 spinal fusion surgeries are performed each year. Spinal fusion surgery involves permanently joining two or more vertebrae in the spine so that there is no movement between the joints. Most of these procedures are performed because of spinal pain due to degeneration of the spine. However, other conditions including spinal instability, scoliosis, spondylolysis, and spondylolithesis can result in chronic spinal pain that requires spinal fusion surgery.

Spinal-Fusion-DiagramDuring a spinal fusion surgery, hardware is usually placed to maintain alignment of the spine until biological fusion takes place. Hardware that is placed can include screws, metal plates, and metal rods. Oftentimes, however, patients can develop chronic pain from the hardware that was placed during their spinal fusion surgery.

Chronic pain is defined as pain that persists for longer than three months. According to the National Institute of Neurological Disorders and Stroke, approximately 20% of individuals affected by acute spinal pain will develop chronic spinal pain that persists beyond one year despite treatment. Not only does chronic pain affect the body, it can have serious implications for a patients’ mental health as well. Chronic pain is often associated with depression, anxiety, and other mood disorders.  It is therefore important to discuss all of your symptoms with your physician to make an educated decision about your treatment options.

A hardware block procedure is a diagnostic procedure that is non-invasive and recommended for patients who suffer from chronic pain following spinal fusion surgery. A hardware block procedure allows the physician to determine if the hardware placed during spinal fusion surgery is actually the cause of a patient’s chronic pain. If it is determined that the hardware is the source of pain, patients are able to try a variety of pain management therapies.

How Is A Hardware Blocks Performed?

Spinal-Fusion-X-RayPatients are placed in either a prone or seated position to expose the area of the spine that is affected. A local anesthetic is then injected into the area where the hardware is located. Lidocaine is a commonly used anesthetic for hardware blocks, as it is effective and has a high potency rate. After the anesthetic is injected, patients are asked to perform some spinal movements.

Following a hardware block, if the patient reports a decrease in pain symptoms, it indicates that the hardware that was placed during the spinal fusion surgery is likely the source of their chronic pain. Conversely, if the patient reports no pain relief following a hardware block procedure, then it is unlikely that the hardware placed during their spinal fusion surgery is the source of their chronic pain. After the hardware block is completed, patients are moved to a recovery room to be monitored for any adverse reactions.

Hardware block procedures are performed in an outpatient setting as it is a non-surgical technique and requires less than an hour to perform. The pain associated with a hardware block is minimal because of the small needle size and short period of time it takes to complete the procedure. Patients are advised to minimize activities for 24 hours following a hardware injection block.

While hardware block procedures are minimally invasive and considered safe, there are risks associated with the procedure, including:

  • Dizziness
  • Nausea
  • Injection site tenderness
  • Headache
  • Infection
  • Hematoma
  • Allergic reaction
  • Local anesthetic toxicity

Patients should consult with their physician if they experience any adverse reactions following a hardware block.

Conditions Related To Hardware Blocks

Human Back DiseaseHardware blocks have been shown to be beneficial for patients experiencing chronic pain following spinal fusion surgery. A hardware block allows the physician to determine if the hardware that was inserted into the patient is the source of pain. The diagnostic information obtained from hardware blocks has proven to be very useful for patients and physicians. The results obtained from this procedure allow physicians to determine the next course of treatment for pain relief, including the potential removal of hardware from a patient’s spine.


A hardware block procedure is a non-surgical, minimally invasive, diagnostic option for patients suffering from chronic pain following spinal fusion surgery. The nerve block can help a physician determine if a patient’s chronic pain is being caused by the hardware that was placed during their spinal fusion surgery or if the pain is originating from elsewhere. A hardware block is not a pain relief treatment; it helps to isolate the source of a patient’s chronic pain.

Once the source of pain is determined, the physician can discuss pain management options with the patient. Pain management options may include a multi-disciplinary approach to address both the physical and mental aspects of a patient’s health. Furthermore, the physician can determine if removal of the surgical hardware is warranted.


  1. Boswell MV, Trescot AM, Datta S, et al.Interventional techniques: evidence-based practice guidelines in the management of chronic spinal pain. Pain Physician. 2007;10(1):7–111.
  2. Camillo FX. Arthrodesis of the spine. In: Canale ST, Beaty JH, eds. Campbell’s Operative Orthopaedics. 11th ed. Philadelphia, PA: Mosby; 2007:1851–74. 70.
  3. Deyo RA, Nachemson A, Mirza SK. Spinal-fusion surgery – the case for restraint. N Engl J Med. 2004;350(7):722-6.
  4. Manchikanti L, Boswell MV, Singh V, et al. Comprehensive evidencebased guidelines for interventional techniques in the management of chronic spinal pain. Pain Physician. 2009;12:699–802.
  5. Mokhtar SA, McCombe PF, Williamson OD, Morgan MK, White GJ, Sears WR. Health-related quality of life: a comparison of outcomes after lumbar fusion for degenerative spondylolisthesis with large joint replacement surgery and population norms. Spine J 2010;10(4):306–312.
  6. nih.gov, (2015). Low Back Pain Fact Sheet: National Institute of Neurological Disorders and Stroke (NINDS). [online] Available at: http://www.ninds.nih.gov/disorders/backpain/detail_backpain.htm [Accessed 9 Jan. 2015].
  7. Ragab, A, deShazo, R. Management of Back Pain in Patients with Previous Back Surgery. The American Journal of Medicine. 2008;121(4):272-278.
  8. Sitzman BT. Pharmacology for the spine injectionist. In: Fenton DS, Czervionke LF, eds. Image-guided spine intervention. Philadelphia: Saunders; 2003:287-92.
  9. Slone RM, McEnery KW, Bridwell KH, Montgomery WJ. Fixation techniques and instrumentation used in the thoracic, lumbar, and lumbosacral spine. Radiol Clin North Am. 1995;33:233–265.
  10. Von Korff M, Crane P, Lane M, Miglioretti DL, et al. Chronic spinal pain and physical-mental comorbidity in the United States: Results from the national comorbidity survey replication. Pain. 2005;113(3):331-9.Affiliations