We used the following entry points: thoracic spine; 3 mm caudal to the junction of the transverse process and the lateral margin of the superior articulating process, and the sagittal trajectory was always orthogonal to the dorsal curvature of the spine at that level as described by Fennel et al, in lumbar spine; the junction of the pars interarticularis
, the midpoint of the transverse process and the inferior point of the superior articular facet, in sacral; the infero-lateral margin of the basis of the superior articular process of the sacrum We collected data on the number of patients, the number of inserted pedicle screws, and parameters of the surgical technique (entry point, axial, and sagittal trajectories).
Spondylolysis is a unilateral or bilateral anatomic defect in the pars interarticularis
without displacement of the vertebral body.
Spondylolysis is generally recognized as a fracture of the lumbar vertebrae through the pars interarticularis
, typically resulting from a variety of strenuous physical activities (Barnes 1994, 2012; Beutler et al.
Spondylolysis is defined as a defect in the pars interarticularis
of the vertebral arch, which is a bony bridge connecting the superior and the inferior articular facet joints.
Spondylosis is defined as a defect in the pars interarticularis
of the vertebral body, which connects the superior and inferior articular facets.
In our case, emergent occiput-C2 fixation was performed with bilateral C2 pars interarticularis
screws and an occiput plate with three midline screws placed in the occiput keel that were connected with precontoured occiput cervical rods.
Spondylolysis is known to be a part of a disease process, which describes a defect in the pars interarticularis
Developmental defect in pars interarticularis
, articulation between the upper and lower vertebrae in lower lumbar spine, can be seen approximately in 5% of young adults.
spondyloptosis) Etiologic (Wiltse (3)) classification * Type 1: Dysplastic Congenital defect of the neural arch * Type 2: Isthmic Pars interarticularis
defect (3 subtypes) a) Stress (fatigue) fracture (most common type, present in this case) b) Elongated pars c) Acute pars fracture * Type 3: Degenerative Facet joint osteoarthrosis * Type 4: Traumatic Acute fracture of the vertebral arch other than the pars * Type 5: Pathological Insufficiency fracture as a result of bone weakening diseases * Type 6: Iatrogenic Fracture secondary to spinal surgery such as laminectomy Table 2.
The lumbar curve is decreased in this position.3 A person with a disc protrusion or disc bulge, can have tight hamstrings4 and sciatic pain can also be associated with the disc herniation which may be due to hamstrings tightness.5 In Spondylolisthesis there are bilateral fractures in the pars interarticularis
of the spine and severe tightness is present in hamstrings group.6
X-ray of the lumbosacral spine revealed reduced intervertebral disc space at LV4/ LV5 and LV5/SV1 levels and grade-I spondylolisthesis at LV5/SV1 level with defect in pars interarticularis
of LV5 (figure 3).
The pedicle screws were then inserted bilaterally by starting at the junction of the transverse process, lateral facet, and pars interarticularis
(or ala and facet, for the sacrum) and then advancing in a lateral to medial and cranial to caudal fashion.