Korean J Sports Med.  2021 Dec;39(4):193-197. 10.5763/kjsm.2021.39.4.193.

Atypical Spondylolysis of the Fifth Lumbar Vertebra in Baseball Players: Two Cases Report

• Cho HL
• Kim DY
• Jin HK
• Kim JH

• KMID: 2523235
• DOI: http://doi.org/10.5763/kjsm.2021.39.4.193

Abstract

Lumbar spondylolysis is a frequent cause of low back pain especially in adolescents involved in sporting activities. It is considered as a fatigue-type defect in the pars interarticularis or isthmus resulted from repetitive hyperextension and rotation on the spine; however, there is still confusion in regard to imaging findings of the location and direction of the defect. We report two unique cases of fifth lumbar spondylolysis in professional baseball hitter and adolescent pitcher; early-stage unilateral incomplete isthmus fracture and bilateral fracture in a different configuration, respectively. Computed tomography demonstrated vertical and more coronally oriented fracture lines compared with typical spondylolytic defect, and repetitive rotation in the same direction of pitching might cause a different type of fracture on the contralateral isthmus with the preexisting unilateral defect. Intriguingly, early-stage unilateral fracture in hitter was united after only 6 weeks of rest and rehabilitation and able to return to the game.

Keyword

Low back pain; Spondylolysis; Atypical; Stress fracture; Isthmus