Neneman discusses Pars Fractures and Spondylolisthesis

Figure 2: SPECT CT Alpha series that initially demonstrates very high osteoblastic activity in a right pars defect with less uptake on the left in a professional rugby player (lock forward). The right-sided activity virtually disappears four months later following strict conservative treatment, but the left becomes more active and the player remains highly symptomatic with pain preventing him from playing or training. In this case, the SPECT CT shows that there is no residual capacity for fracture healing on the right and the instability caused by the pars non-union is causing increased stress on the left therefore surgical treatment is warranted.

Spondylolisthesis, Pars Defect & Stress fracture

If the fracture gap at the pars widens, then the condition is called Spondylolisthesis

Spondylolisthesis with pars defect - …

Repetitive trauma means extension movements of the spine, with lateral flexion, which increase the shearing stress at the pars interarticularis and result in a stress fracture.

Spondylolysis and Spondylolisthesis - OrthoInfo - AAOS

Spondylolysis (spon-dee-low-lye-sis) and spondylolisthesis (spon-dee-low-lis-thee-sis) are separate, yet related conditions. Spondylolysis usually comes first, though not always. The term comes from "spondylo," which means "spine," and "lysis," which means to divide. Spondylolysis is a breakdown or fracture of the narrow bridge between the upper and lower facets, called the pars interarticularis. It can occur on one side (unilateral) or both sides (bilateral) and at any level of the spine, but most often at the fourth or fifth lumbar vertebra (Fig. 2). If spondylolysis is present, then you have the potential to develop spondylolisthesis.

What Are Spondylolysis and Spondylolisthesis? Spondylolysis is a defect or fracture of part of the vertebral bones called the pars interarticularis.

Three stages of injury to the pars interarticularis—the ..

The lytic (subtype a) results from the separation or dissolution of the pars. The incidence of this type of Spondylolisthesis increases from less than 1 percent in children 5 years of age to 4.5 percent in children 7 years of age. The remaining 0.8 to 1 percent increase occurs between the ages of 11 to 16 years, presumably because of stress fractures caused by athletic activity. Extension movements of the spine, with lateral flexion, can increase the shearing stress at the pars interarticularis and result in Spondylolysis.

Many people with spondylolysis and spondylolisthesis never become ..

A unilateral pars defect (spondylolysis) may not demonstrate any degree of slippage; thus, a patient may have spondylolysis without spondylolisthesis. The reverse is also true as in the degenerative-type slips described below.

The stress fracture of the pars ..

Spondylolisthesis is generally defined as an anterior or posterior slipping or displacement of one vertebra on another. A unilateral or bilateral defect (lesion or fracture) of the pars interarticularis without displacement of the vertebra is known as Spondylolysis. The pars interarticularis is the posterior plate of bone that connects the superior and inferior articular facets of a vertebral body.

Spondylolysis | Radiology Reference Article | …

Type I. Dysplastic: This type results from congenital abnormalities of the upper sacral facets or inferior facets of the fifth lumbar vertebra that allow slipping of L5 on S1. There is no pars interarticularis defect in this type. The sacrum is not strong enough to withstand the weight and stress. Thus, the pars and inferior facets of L5 are deformed. If the pars elongates, it is impossible to differentiate it by x-ray from the isthmic (type II b) Spondylolisthesis. If the pars separates, it becomes impossible to differentiate it by x-ray from the isthmic lytic (type II a) Spondylolisthesis. This type is also associated with sacral and neural arch deficiencies. It has a familial tendency.

resulting in stress fracture of the pars ..

In traumatic spondylolisthesis, any part (usually not the pars) of the neural arch can be fractured, leading to the unstable vertebral subluxation.