Rheumatology Advance Access originally published online on October 18, 2005
Rheumatology 2006 45(2):209-211; doi:10.1093/rheumatology/kei134
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Degenerative spondylolysis: a concise report of scintigraphic observations
Departments of Nuclear Medicine, 1 Rheumatology, 2 Orthopedics and 3 Radiology, Concord Hospital and 4 University of Sydney, Sydney, Australia.
Correspondence to: H. Van der Wall, Department of Nuclear Medicine, Concord Hospital, Hospital Road, Concord 2139, Australia. E-mail: hansv{at}nmrf.org.au
 |
Abstract |
|---|
 Top Abstract IntroductionMethodsResultsDiscussionConclusionReferences |
|---|
Objectives. Spondylolysis is traditionally thought to be a diagnosis of adolescence and childhood, and is ascribed to mechanical stress through the immature pars interarticularis. Over the last 4 yr we have noted a presentation of spondylolysis in association with hypertrophic zygapophyseal joint disease in the lumbar spine in an older age group.
Methods. Records of 94 patients presenting with low back pain were examined. A pattern of intense zygapophyseal joint uptake in association with extended uptake in the pars interarticularis was ascribed as degenerative spondylolysis.
Results. The ages of the 94 cases ranged from 33 to 80 yr (mean 64 yr). There were 53 males and 41 females. In the group with degenerative spondylolysis the mean age was 72 yr, with four females and two males. None of these six patients gave a history of childhood spinal disease or back pain and all were relatively inactive in terms of current participation in sport. All cases of spondylolysis were confirmed by computed tomography scanning.
Conclusion. The finding of hypertrophic zygapophyseal joint disease in association with spondylolysis is easily recognized by scintigraphic tomographic imaging.
KEY WORDS: Scintigraphy, Degenerative spondylolysis, Fracture, Facet joint
|
Introduction |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionConclusionReferences |
|---|
Spondylolysis has traditionally been a diagnosis made in adolescents or young adults who generally engage in sporting activity [1–3]. The pathophysiology is predicated on a stress or overuse injury [4] and/or, less commonly, on a congenital abnormality of the pars [5]. The finding of spondylolysis in later life is rare. The dominant patterns of presentation are with degenerative disease of the intervertebral disc, vertebral body and facet joints. Rarely, older patients may present with degenerative spondylolisthesis without a pars interarticularis fracture and this occurs in a subgroup with sagitally oriented facet joints [6] which fail to lock the vertebral bodies together.
Degenerative disease may affect the spine in later life, predominantly involving the intervertebral disc and facet joints [7]. Severe facet joint disease is occasionally characterized by exuberant osteophyte formation and marked reduction in movement at the level of the facet joint. This may transfer the extremes of flexion–extension and rotational forces from the facet joints to the pars interarticularis, leading to increased stress and eventual secondary spondylolysis. These forces have been investigated in cadaveric models of the childhood variety of spondylolysis and shown to be important in development of the fracture [8]. We have observed the concurrence of severe facet joint disease and fracture of the pars interarticularis in a number of older patients on bone scintigraphy, a finding that has not been reported previously.
|
Methods |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionConclusionReferences |
|---|
Patients
Records of all consecutive patients presenting with low back pain were drawn from a database maintained in nuclear medicine. The maintenance of a musculoskeletal database was approved by the institutional ethics committee and is stored in a secure password-protected computer database. The subgroup of patients undergoing scintigraphic single-photon emission computed tomography (SPECT) of the lumbar spine was drawn from this database. Records from patients under the age of 20 yr were discarded in order to remove the athletic subgroup with the more common form of spondylolysis. The majority of patients (74%) gave a history of chronic low back pain of greater than 6 months duration but with progressively worsening pain. A smaller subgroup (18%) presented with acute worsening (<3 months duration) of chronic back pain (>6 months duration). The remainder had stable but significant low back pain of greater than 3 months duration.
Imaging
All patients routinely underwent three-phase bone scanning. Patients were imaged on either a dual-headed or triple-headed gamma camera (MS2 or MS3, Siemens, Chicago, IL, USA) after injection of 900–1000 MBq of 99mTc methylene diphosphonate (MDP). Planar and SPECT images of the spine were obtained and reconstructed in the three standard projections. All studies were reported by a senior nuclear medicine physician on an Icon workstation (Siemens). The criterion for diagnosis of facet joint disease was increased uptake of tracer in the posterolateral elements of the lumbar spine at the level of the intervertebral disc (Fig. 1). Pars interarticularis fractures were diagnosed if increased uptake was evident in the posterolateral elements but at the level of the vertebral body [8] or by the triangular pattern of uptake (Fig. 1), which has been described previously [9]. X-ray computed tomography (CT) scans were also reviewed for each patient and films reported in a blinded fashion for patients with facet joint disease/spondylolysis. The angle of orientation of the facet joint in the sagittal plane was determined as described elsewhere [6].
|
Data analysis
Due to the small number of patients with the condition, only descriptive statistics were undertaken.
|
Results |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionConclusionReferences |
|---|
Patients
Records of 94 patients were reviewed. Ages ranged from 33–80 yr (mean 64 yr). There were 53 males and 41 females. In the group with degenerative spondylolysis, the mean age was 72 yr with four females and two males. All patients gave a history of chronic low back pain with acutely worsening symptoms. All cases were at L5, with one being bilateral (Fig. 2). None of these six patients gave a history of childhood spinal disease or back pain and all were relatively inactive in terms of current participation in sport.
|
|
Imaging
The patterns of uptake are shown in Table 1. Six of the 94 patients showed the pattern of facet joint and pars interarticularis uptake characterizing degenerative spondylolysis. A variety of patterns of uptake were found in the others. These included zygapophyseal joint changes, spondylotysis, unexpected metastatic malignancy, compression fractures, peridiscal uptake and, in a small group, no significant scintigraphic abnormality. The six patients with spondylosis had CT scans confirming both osteophytic hypertrophic zygapophyseal joint disease and spondylolysis (Fig. 2). All patients had relative thickening of the pars around the fracture site. The angles of the zygapophyseal joints were in the normal range (<45°), as reported by Grobler et al. [6]. None of these patients had previous CT scans or films that could be utilized to evaluate the possibility of remote pre-existing pars interarticularis fractures.
|
|
Discussion |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionConclusionReferences |
|---|
Low back pain is a common phenomenon with a plethora of causes extending from intervertebral disc disease to zygapophyseal degeneration, compression fracture, metastatic malignancy and a number of soft tissue processes. This complaint is one of the most common in the general community and has been reported in up to two-thirds of some populations [10, 11]. To attempt imaging in everyone with low back pain would be a monumental task and involve major costs to the health-care system. Imaging in our group of patients was mostly for progressive or acute worsening of pain on a background of chronicity of greater than 6 months duration. Many of these patients routinely undergo CT scanning and SPECT bone scintigraphy as a prelude to symptomatic treatment of zygapophyseal joint disease with a mixture of steroid and long-acting local anaesthetic under CT guidance. The joints are selected on the basis of intense scintigraphic uptake. This may in fact have led to some degree of selection bias in the group of patients studied with scintigraphy in this study.
While spondylolysis in our group of patients was characterized by acutely worsening pain, this pattern of pain was also found in patients with joint disease only and sometimes with no abnormality on the scintigraphic study. The high prevalence (86%) of at least some scintigraphic abnormality is not unexpected as there was some patient selection bias. Furthermore, tomographic studies were acquired on all patients with a high-resolution multiheaded gamma camera and even minor changes were reported for the purposes of the study.
In general, the most common cause of low back pain is thought to be intervertebral degenerative disc disease [7]. The combination of hypertrophic degenerative zygapophyseal joint disease and spondylolysis has not been recorded previously and was not found in a computerized search of the Medline database. There are, however, reports of degenerative spondylolisthesis in a subgroup of patients without a pars interarticularis fracture, but with sagittally orientated zygapophyseal joints [6], who present with either increasing lower back pain or symptoms of radiculopathy/spinal canal stenosis. The mechanism is thought to be progressive slippage of one vertebral body on another due to a failure of locking of the zygapophyseal joints. None of the patients in our series presented with spondylolisthesis and all had zygapophyseal joint angles that were within the normal limits.
The other potential explanation of the combination of degenerative zygapophyseal joint disease and spondylolysis is of the possibility of a pre-existing spondylolysis, dating back to childhood, with secondary zygapophyseal joint disease. This combination would, however, be unlikely on a mechanical basis as spondylolysis would unload the ipsilateral zygapophyseal joint from the effects of stress during flexion–extension–rotational movement. It may in fact lead to an increased load on the contralateral zygapophyseal joint, predisposing the contralateral pars to a possible fracture, as occurred in one of the patients (Fig. 2). Importantly, in all 6, both zygapophyseal joints at the level of the spondylolysis demonstrated hypertrophic degenerative disease. Moreover, in long-term follow-up of symptomatic adolescents with spondylolysis, the majority will have resolution of their symptoms by adulthood. This was the finding in 20 of 31 patients with spondylolysis followed up for 28 yr [12].
The likeliest mechanism for spondylolysis in this setting is a lever-arm phenomenon on the pars [1] resulting from increasing immobility of the ipsilateral zygapophyseal joint. Immobility would increasingly transfer the stresses of extension and flexion to the adjacent pars interarticularis, subjecting it to chronic stress. This mechanism is supported by the observation that all patients affected had relative thickening of the involved pars, suggesting a hypertrophic response to the increased load according to Wolff's law [13]. The immobility would result from the hypertrophic response to stress-induced degenerative changes on the zygapophyseal joint, such that there is effective ankylosis. The occurrence of the fracture may then be characterized by a change in the pattern of lower back pain.
|
Conclusion |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionConclusionReferences |
|---|
The finding of hypertrophic zygapophyseal joint disease in association with ipsilateral spondylolysis occurs in a small proportion of patients and is easily recognized by scintigraphic tomographic imaging. We postulate that the mechanism is related to increasing immobility at the zygapophyseal joint with subsequent transfer of stress to the ipsilateral pars. This is associated with thickening of the pars prior to eventual fracture.
The authors have declared no conflicts of interest.
|
References |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionConclusionReferences |
|---|
- Hutton WC, Cyron BM. Spondylolysis. Acta Orthop Scand 1978;49:604–9.[Web of Science][Medline]
- Mandell GA, Harcke HT. Scintigraphy of spinal disorders in adolescents. Skeletal Radiol 1993;22:393–401.[CrossRef][Web of Science][Medline]
- Oakley RH, Carty H. Review of spondylolisthesis and spondylolysis in paediatric practice. Br J Radiol 1984;57:877–85.
[Abstract/Free Full Text] - Jackson DW, Wiltse LL, Dingeman RD, Hayes M. Stress reactions involving the pars interarticularis in young athletes. Am J Sports Med 1981;9:304–12.
[Abstract/Free Full Text] - Abraham T, Holder L, Silberstein C. The retroisthmic cleft. Scintigraphic appearance and clinical relevance in patients with low back pain. Clin Nucl Med 1997;22:161–5.[CrossRef][Medline]
- Grobler LJ, Robertson PA, Novotny JE, Pope MH. Etiology of spondylolisthesis. Assessment of the role played by lumbar facet joint morphology. Spine 1993;18:80–91.[CrossRef][Medline]
- Andersson GB. What are the age-related changes in the spine? Baillieres Clin Rheumatol 1998;12:161–73.[Medline]
- Gates GF. Oblique angle bone SPECT imaging of the lumbar spine, pelvis and hips. Clin Nucl Med 1996;21:359–62.[Medline]
- Van der Wall H, Storey G, Magnussen J et al. Distinguishing scintigraphic features of spondylolysis. J Pediatr Orthop 2002;22:308–11.[CrossRef][Medline]
- Manek NJ, MacGregor AJ. Epidemiology of back disorders: prevalence, risk factors, and prognosis. Curr Opin Rheumatol 2005;17:134–40.[CrossRef][Web of Science][Medline]
- Scutellari PN, Rizzati R, Antinolfi G, Malfaccini F, Leprotti S, Campanati P. The value of computed tomography in the diagnosis of low back pain. A review of 2012 cases. Minerva Med 2005;96:41–59.[Medline]
- Hefti F, Brunazzi M, Morscher E. Natural course in spondylolysis and spondylolisthesis. Orthopade 1994;23:220–7.[Medline]
- Frost HM. A 2003 update of bone physiology and Wolff 's law for clinicians. Angle Orthod 2004;74:3–15.[Web of Science][Medline]
CiteULike 
Connotea 
Del.icio.us What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||