Fracture of the Inferior Articular Process of the Lumbar Spine.

We report four cases with fractures of the inferior articular process of the lumbar spine.Case 1 was a 16-year-old male, who complained of low-back pain after playing soccer. Radiographs showed a fracture of the left inferior articular process of the second lumbar spine.Case 2 was an 18-year-old female who complained of low-back pain after falling from a bicycle. Radiographs revealed a fracture of the bilateral inferior articular processes of the fourth lumbar spine.Case 3 was an 18-year-old male, who had developed low-back pain after lifting a barbell. Radiographs disclosed a fracture of the right inferior articular process of the fourth lumbar spine.Case 4 was a 24-year-old male, complaining of low-back pain after playing tennis. He had a history of intermittent low-back pain for four years.X-rays revealed non-union of the bilateral inferior articular processes of the third lumbar spine. In three out of the four cases the defects did not unite by conservative treatment.Therefore, it is considered that non-union dose not always cause low-back pain.