Pars defects and

Spondylolisthesis

Dr Paul Licina

Dr Mark Young

Pars Interarticularis

Pars and Pedicle fracture

Spondylolysis: A defect in the pars interarticularis of the vertebral arch

Spondyolisthesis

Spondylolisthesis (anterolisthesis): Forward displacement of a

superior vertebral body over the vertebral body below (include

isthmic, dysplastic and others)

Pars Fractures

• Combination of hereditary and lifestyle factors

• Family history, racial preponderance

• Approx 50/50 developmental v repetitive trauma

• 85% L5

• Spinabifida Occulta

• 8% of population have pars # (+/- symptoms)

• PM- approx 4% pars #, 2% isthmic spondylolisthesis

Athletic Pars fractures

• ??Adolescence

• Extension sports (esp gymnastics, cricket

bowling, divers, throwing athletes, ?ball

sports)

• Usually symptomatic

• Contralateral side

• Some sports L4 > L5

Extension produces inferior Pars

tension stress

Imaging

• MRI (with “pars protocol”) for diagnosis

• Limited (spiral/helical) CT scan for staging

– early, progressive or terminal (‘pars defect’)

• Xray – ??to monitor spondylolisthesis

• Bone scan – if claustrophobic, or cant have

MRI

– sensitive but not specific

Brisbane Radiology

“Pars Protocols”

• Qscan – Sagittal T1, Sagittal T2 fat sat, Axial T2

• BPI – 3D STIR Sagittal + Axial, 3D T1 + gradient echo (tailored for water), T2 Axial

• Qld Xray – 3D STIR Coronal & Axial, T2, T1 Sagittal STIR (gradient echo), T2 Axial +/- limited CT scan

Treatment is Multidisciplinary

• Rest from provoking activity – how long?

• Core stability exercises (avoid extension)

• Cross train - sports specific (add pain free cycle at 1-2 weeks & swim 2-3 weeks, run around 6 weeks, return to sport 12-18 weeks)

• Correct biomechanical factors

• ?Vit D/BMD

• ?BRACE

• ?RE-IMAGE