Figure 1
Computed Tomography
Isthmic spondylolisthesis
SectionNeuroradiology
Case TypeClinical Cases
AuthorsFeutry G, Vargas M-I.
Connected authors
40 years, female
Clinical History
A forty-year-old woman with no particular medical history consulted her general practitioner for lower back pain for several years, urinary incontinence for three months, and fecal incontinence for one month. She was referred to the emergency department for imaging.
Imaging Findings
Computed tomography revealed grade III anterolisthesis of L5 on S1 according to Meyerding classification and a bilateral defect in pars interarticularis. Voluminous anterior osteophytes on S1 confirmed a chronic affection.
Magnetic resonance imaging realized the same day showed a severe stenosis of the spinal canal with compression of the cauda equina, responsible for the patient's symptoms. It also showed bilateral foraminal stenosis and Modic type 1 endplate signal anomalies.
In view of her neurological symptoms, surgery was performed. She benefited from posterior decompression and postero-lateral fixation from L4 to S1, as well as L5-S1 discectomy and interbody cage placement.
Postoperative CT showed that the sagittal alignment was satisfying and the disc height had been restored.
Complete regression of symptoms after surgery.
Magnetic resonance imaging realized the same day showed a severe stenosis of the spinal canal with compression of the cauda equina, responsible for the patient's symptoms. It also showed bilateral foraminal stenosis and Modic type 1 endplate signal anomalies.
In view of her neurological symptoms, surgery was performed. She benefited from posterior decompression and postero-lateral fixation from L4 to S1, as well as L5-S1 discectomy and interbody cage placement.
Postoperative CT showed that the sagittal alignment was satisfying and the disc height had been restored.
Complete regression of symptoms after surgery.
Discussion
Spondylolisthesis is the forward translocation of a vertebral segment over the one beneath it.
There are five types of spondylolisthesis: Isthmic, dysplastic, degenerative, traumatic and pathologic [1]. We will discuss the isthmic pattern, since the clinical context of our patient directs us to that pathophysiology. In this group, anterolisthesis occurs in 50 to 70% of people with spondylolysis [2].
A conjugation of mechanical and anatomical factors lead to the development of spondylolysis. It can be considered a fatigue fracture caused by mechanical stress on the lower lumbar spine when learning to walk in childhood or excessive sports training.
Spondylolysis is twice as frequent in men as in women, but slippage affects women two to three times more than men [1].
Moreover, there are significant ethnic variations of spondylolysis, with a prevalence of up to 54% in adult Inuits and 6% to 11.5% for Caucasians [3].
The most commonly affected level, for about 90% of the patients, is the lumbo-sacral joint [3].
Generally asymptomatic, spondylolisthesis can however manifest as lower back pain and even, as in our case, a cauda equina syndrome. It results from impingement on the nerve root or on the cauda equina.
Meyerding grading system is used to describe the percentage of displacement of the cranial vertebra on the one beneath it. Grade I means a translation of up to 25%, grade II of up to 50%, grade III of up to 75% and grade IV of up to 100%.
Work up of these patients includes CT and MR imaging. CT is used for the analysis of bone structures to identify the spondylolysis. MR is used to identify complications such as nerve root impingement or cauda equina syndrome.
Most patients with axial or radicular pain related to lumbar spondylolysis will improve with non-surgical treatment, non-steroidal anti-inflammatory drugs and muscle relaxants.
If the slippage is over Meyerding grade III, or in case of intractable pain or neurologic symptoms, the patient may benefit from surgical decompression and stabilization.
There are five types of spondylolisthesis: Isthmic, dysplastic, degenerative, traumatic and pathologic [1]. We will discuss the isthmic pattern, since the clinical context of our patient directs us to that pathophysiology. In this group, anterolisthesis occurs in 50 to 70% of people with spondylolysis [2].
A conjugation of mechanical and anatomical factors lead to the development of spondylolysis. It can be considered a fatigue fracture caused by mechanical stress on the lower lumbar spine when learning to walk in childhood or excessive sports training.
Spondylolysis is twice as frequent in men as in women, but slippage affects women two to three times more than men [1].
Moreover, there are significant ethnic variations of spondylolysis, with a prevalence of up to 54% in adult Inuits and 6% to 11.5% for Caucasians [3].
The most commonly affected level, for about 90% of the patients, is the lumbo-sacral joint [3].
Generally asymptomatic, spondylolisthesis can however manifest as lower back pain and even, as in our case, a cauda equina syndrome. It results from impingement on the nerve root or on the cauda equina.
Meyerding grading system is used to describe the percentage of displacement of the cranial vertebra on the one beneath it. Grade I means a translation of up to 25%, grade II of up to 50%, grade III of up to 75% and grade IV of up to 100%.
Work up of these patients includes CT and MR imaging. CT is used for the analysis of bone structures to identify the spondylolysis. MR is used to identify complications such as nerve root impingement or cauda equina syndrome.
Most patients with axial or radicular pain related to lumbar spondylolysis will improve with non-surgical treatment, non-steroidal anti-inflammatory drugs and muscle relaxants.
If the slippage is over Meyerding grade III, or in case of intractable pain or neurologic symptoms, the patient may benefit from surgical decompression and stabilization.
Differential Diagnosis List
Grade III L5-S1 spondylolisthesis
Post acute trauma displacement
Ephiphysitis
Final Diagnosis
Grade III L5-S1 spondylolisthesis
References
[1] Serena S. Hu, MD; Clifford B. Tribus, MD; Mohammad Diab, MD; Alexander J. Ghanayem, MD J Bone (2008) Spondylolisthesis and Spondylolysis. The Journal of Bone & joint surgery 90 (3): 656 -671 (PMID: 18326106)
[2] Jones TR, Rao RD (2009) Adult Isthmic Spondylolisthesis. Journal of the American Academy of Orthopaedics Surgeons 17(10):609-17 (PMID: 19794218)
[3] Tsirikos AI, Garrido EG (2010) Spondylolysis and spondylolisthesis in children and adolescents. Journal of Bone & Joint Surgery, British Volume vol. 92-B no. 6 751-759 (PMID: 20513868)
Case information
| URL: | https://eurorad.org/case/12214 |
| DOI: | 10.1594/EURORAD/CASE.12214 |
| ISSN: | 1563-4086 |
Post-operative CT
Sagittal post-op CT shows reduction of the slippage.
HUG
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