Spondylolysis
A fatigue fracture of the pars inter-articularis is also called spondylolysis. This may be unilateral or bilateral. It can be the cause of back pain. It is common in sports such as cricket, football, gymnastics, diving, rugby and weight lifting. It is diagnosed on MRI, though CT scans are better at assessing the site and type of the defect.
Treatment is usually conservative and includes physiotherapy , bracing and local injections. Surgery is sometimes required to repair the defect.