Unilateral Pars-Defect; Early Diagnosis and Chiropractic Management (IRCA Monthly Conferences, May 28, 2015) Introduction Back Ground: Incidence of pars defect is about 5 to 7% of the general population. Even so, this condition is a major contributor to progressive biomechanical dysfunction . . . You should be signed up and logged in and approved by Admin to see this content.