Synchronic multiple stress fractures of L5 left hemilamina: a case of an unusual type of lumbar spondylolysis.

Lumbar spondylolysis is a stress fracture that commonly occurs in adolescent sports players. It is found in approximately 6% of the adult general population. The condition is usually detected as a defect in the pars interarticularis, sometimes in the pedicle (pediculolysis), and rarely in the lamina (laminolysis). Such fractures are typically seen as one defect in each side of the lamina: multiple stress fractures in the same side of the lamina rarely occur synchronically. Here, we report an unusual type of lumbar spondylolysis in the form of synchronic multiple stress fractures of the L5 left hemilamina in an adolescent baseball player. Conservative treatment was effective for bony healing. Although this type of spondylolysis is very rare, to avoid overlooking it, it is essential to examine reconstructed CT images and take the patient's history carefully. If an accurate diagnosis is made early, conservative treatment may be sufficient to achieve bony healing.