- Clinical science
The term spondylolisthesis defines a condition in which the vertebral bodies slip forward in relation to the vertebrae beneath. Most commonly L5 slips over S1. The disease affects approx. 6–9% of the population. The condition most commonly occurs in children, adolescents, and in individuals > 50 years old. Risk factors are repetitive hyperextension of the spine (e.g., gymnastics), trauma, bone pathologies, or degenerative spine disease. Spondylolisthesis may be asymptomatic or cause lumbar pain on exertion, gait problems, radiculopathic pain, or urinary incontinence. In some patients a step-off at the lumbosacral area is palpable. Diagnosis is established through imaging. Most patients achieve good results with conservative treatment (e.g., physical therapy). Surgical treatment (e.g, vertebral fusion, decompression of the nerves) is reserved for patients with refractory cases and neurologic deficits. Overall, children and adolescents achieve better results than adults and elderly.
- Affects up to 10% of the population
- Most common in children < 6 years, 12–17 years (congenital and spondylolytic form) and adults aged > 50 years (degenerative form)
- Sex: ♂ > ♀ (congenital and spondylolytic form); ♀ > ♂ (degenerative form)
- Defect most commonly occurs in the lumbar spine (L5 in 80% of cases), L4 in 15% of cases
Epidemiological data refers to the US, unless otherwise specified.
- Risk factors:
- Congenital malformation (dysplasia or hypoplasia) of the lumbosacral joints in L5–S1
Repetitive hyperextension and rotation movements at L5–S1
- Commonly associated with gymnastics, swimming, and weight lifting
- Spondylolysis: lytic defect in the pars interarticularis, permitting forward slippage of the superior vertebra
- Degenerative disease: most commonly in the elderly at L4–L5
- Local or systemic pathology (e.g., tumor, , , )
- Asymptomatic (∼ 90% of cases)
- Chronic lumbar pain that worsens with exertion and/or when reclining
- Gait problems (e.g., waddling gait)
- Possibly urinary or bowel incontinence
- Step-off sign: In advanced stages, a noticeable step-off at the lumbosacral area may be palpated or even seen when the patient is standing.
- : A straight leg raise with the patient lying on the back causes pain and therefore triggers elevation of the entire trunk (to relieve the pain).
- Tight, contracted hamstring muscles
- Possible weakness and atrophy in lower legs; reduced sensation and reflexes
- Provocative test: The relief from pain after local injection of lidocaine at the level of the pars interarticularis may help confirm the diagnosis.
- Conventional x-ray of lumbosacral spine
- Indication: to evaluate the vertebral structures, the degree and severity of forward slippage, the slip angle, and the presence of concomitant spine pathologies
- Usually spondylolisthesis is an incidental finding.
- Meyerding classification → 5 stages: The amount of forward translation of the cranial vertebra over the caudal vertebra is measured in percentage on a lateral radiograph.
- Specific signs:
- Scotty dog with a collar sign in spondylolysis: normal appearance of the lumbar spine in an oblique projection at 45° is referred to as "Scotty dog sign" → in spondylolysis, the fracture line appears as the "dog's collar"
- Inverted Napoleon's hat sign in spondyloptosis: in the case of severe subluxation of L5 over S1
- Conventional x-ray of lumbosacral spine
- CT scan: used to rule out other causes of pain (e.g., tumor), in traumatic cases, and to guide surgical treatment.
- MRI: helps visualize the compression of the nerve roots
- SPECT (Single-photon emission computed tomography): useful in detecting stress injuries or defects, their progression and healing potential, guiding the treatment
Facet joint syndrome
- Irritation of the facet joints, usually due to spondyloarthritis
The differential diagnoses listed here are not exhaustive.
- Indication: patients with low-grade spondylolisthesis (< 50% slippage of cranial vertebra over the caudal vertebra) and degenerative spondylolisthesis with no neurological deficits
- Physical therapy emphasizing training of back and abdominal muscles
- Activity modification: avoid sports which contribute to spondylolisthesis
- Orthotic braces
- Facet or epidural steroid injections to relieve radicular pain.
- Regular follow-ups every 6 months
- Indication: high-grade spondylolisthesis (> 50% slippage of cranial vertebra over the caudal vertebra), neurologic deficits, traumatic spondylolisthesis or if symptoms progress despite conservative treatment
- Standard procedure: vertebral fusion
- Nerve decompression in the case of radiculopathic pain or bowel/bladder dysfunction
- Conservative treatment gives satisfactory results in 80% of cases.
- The rate of success from surgical treatment is higher in children than in adults.