530 - Unusual case of grade II L5-S1 Spondylolisthesis in a very active amateur rower

Case Diagnosis: Grade II anterolisthesis of L5 on S1

Case Description: A 69-year-old male with a distant history of back trauma from football 50 years ago, presented to the outpatient clinic with progressive numbness in the left lower leg and foot over past year. Of note, he has done recreational rowing for many years. Then he gradually has had increased numbness in the left leg and foot with rowing. He reports he only gets this numbness while rowing on the boat, and it resolves in few minutes after the session. He denies any weakness or pain during daily activities. On physical examination, neurological examination was overall intact with normal motor and sensory of bilateral lower limbs except for palpable L5 step-off with extension. Subsequent X-rays of lumbosacral spine demonstrated salient finding of grade II anterolisthesis of L5 on S1 and severe degenerative disc disease at L5-S1.

Discussions: Unusual case of spondylolisthesis which only certain position (rowing in the boat) induces left L5 radicular paresthesia in consideration of relatively high percentage (~50%) of anterior slippage on the image. Spondylolisthesis has a high prevalence in rowers due to repetitive loading from frequent lumbar extension and rotation during the rowing stroke causing stress at pars interarticularis. Thus, it’s crucial to identify common back injuries early in rowing population with thorough physical examination with diagnostic modalities. Furthermore, prompt therapy with emphasis on activity modification such as analyzing rowing stroke to optimize lumbo-pelvic motion to minimize lumbar spine loading, and core endurance-training program can be beneficial to prevent potential injury.

Conclusions: Identifying spondylolisthesis patients in rowing population is essential to prevent further injury with emphasis on appropriate activity modification. This case reinforces the observation that clinical presentation does not mirror severity of radiographic abnormalities.