The Role of Bone SPECT/CT in Evaluation of Persistent or Recurrent Back Pain Following Spine Surgery
The Role of Bone SPECT/CT in Evaluation of Persistent or Recurrent Back Pain Following Spine Surgery
-  To evaluate the role of SPECT/CT in assessment of the osteoblastic activity in patients
 with persistent or recurrent back pain after spine surgery with inconclusive CT/MRI
 findings.

 -  To assess the value of bone SPECT/CT in the management of back pain.
Low back pain is a common disorder, with international studies having found prevalence rates
 between 12% and 35% and life time prevalence rates ranging from 49% to 80%.

 It is caused mainly by degenerative spinal disorders, such as spondylolisthesis, degenerative
 scoliosis, degenerative disc disease and recurrent disc herniations.

 The management of low back pain varies from conservative to more invasive methods, such as
 spinal stabilization surgery that involves the placement of metallic screws, rods, plates or
 cages. Such surgery is increasingly performed to improve spinal stability in a variety of
 spine pathologies, including disc degeneration, spinal stenosis and spondylolisthesis.

 On the other hand, spinal fusion surgery is performed in patients with severe chronic back
 pain when segmental instability is believed to cause the symptoms. The rationale for this is
 that pain relief will be achieved once the fusion restricts motion in the painful segments.
 For this purpose, a wide array of techniques has been proposed, including dorsal or
 dorsoventral spondylodesis, either in a one-step or two-step procedure.

 It is estimated that more than 300,000 lumbar spinal fusion procedures are performed annually
 in the United States, and a continuously rising trend has also been observed in other parts
 of the world.

 Unfortunately, recurrent pain after spinal surgery is a well known problem. It is reported
 that up to 10-20% of patients experience persistent/recurrent pain after lumbar spinal
 instrumentation and fusion , with studies estimating the surgical reintervention rate to be
 around 14% over a 4-year follow-up period and 19% over 11 years.

 This may be related to loosening of the metallic implants or to a failure of a stably
 implanted graft to immobilize the fused segments. A further differential diagnosis is
 degenerative disease involving the spinal segments above or below the instrumented region.
 This so-called adjacent instability (AI) or adjacent level disease (ALD) may be precipitated
 by arthrodesis, as this procedure alters the biomechanics of the spine, thereby increasing
 motion of a mechanical load on the segments neighboring the graft. The differentiation
 between these conditions has therapeutic consequences as the treatment varies according to
 the cause.

 Standard evaluation of patients with persistent or recurrent pain following spinal
 stabilization surgery includes clinical examination and conventional imaging using plain
 radiography, CT or MR imaging.

 Conventional imaging is performed for the evaluation of hardware position (changes), hardware
 failure, fusion evolution, alignment of the vertebrae, possible pseudarthrosis and hardware
 loosening.

 In general, because of the presence of nonspecific postoperative changes and metal-related
 imaging artifacts, the interpretation of CT images is often challenging and inconclusive.
 Thus, whether surgical reintervention is indicated based on conventional imaging may prove
 difficult to ascertain.

 The value of bone scintigraphy with single-photon emission tomography/computed tomography
 (SPECT/CT) in patients with persistent or recurrent back pain after spine stabilization
 surgery has been addressed in a number of studies and the technique has been suggested to be
 a useful diagnostic tool for identification of postsurgical spine pathology.

 Although most of these studies were based on a small sample size and lacked robust reference
 standards; it has been concluded that the use of SPECT/CT adds value in assessing patients
 following spinal surgery.
Inclusion Criteria:

 -  Patients with persistent/recurrent back pain after spine surgery and inconclusive
 conventional imaging.

 -  All patients will be clinically assessed by orthopedic surgeons or neurosurgeons
 specialized and experienced in spine surgery.

 Exclusion Criteria:

 -  Patients less than 18 years old.

 -  Patients in whom stabilization surgery is secondary to a destructive bone malignancy
 (including multiple myeloma).

 -  Patients with known metabolic bone disease (such as Rheumatoid Arthritis, AS & SLE)