802 F-39 Clinical Case Slide ‑ Spine II Friday, May 31, 2019, 3:15 PM - 4:55 PM Room: CC-202C 2911 May 31 3:15 PM - 4:55 PM Chair: Sherrie L. Ballantine-Talmadge, FACSM. CU Sports Medicine and Performance Center, Boulder, CO. (No relationships reported) 2912 May 31 3:15 PM - 4:55 PM Discussant: Dina C. Janse van Rensburg, FACSM. University of Pretoria, Pretoria, South Africa. (No relationships reported) 2913 May 31 3:15 PM - 4:55 PM Discussant: Lindsay Ramey. University of Texas Southwestern Medical Center, Dallas, TX. (No relationships reported) 2914 May 31 3:15 PM - 3:35 PM Progressive Asymmetric Low Back Pain in a Young Basketball Player Marianne Luetmer, Edward Laskowski, FACSM. Mayo Clinic, Rochester, MN. Email: luetmer.marianne@mayo.edu (No relationships reported) HISTORY: A 23 year old otherwise healthy male basketball player developed acute onset of sharp right-sided low back pain upon landing after performing a slam dunk. He had no lower extremity radicular pain, focal weakness, or sensory loss; no constitutional symptoms. At first presentation he was diagnosed with mechanical low back pain. The prescribed physical therapy intervention was beneficial however his pain progressed. He returned to Sports Clinic one year later; the pain had spread to his right gluteal region and was exacerbated by impact exercise. He could no longer play basketball and pain interfered with daily activities. PHYSICAL EXAMINATION: On initial examination: tight hip internal and external rotators bilaterally, negative Stinchfield and FABER tests bilaterally, and tenderness to palpation over right lumbar paraspinals with an otherwise normal exam. One year later: strength, sensation, and reflexes remained intact. Focal tenderness over right SIJ. Normal lumbar ROM. FABER and Stinchfield tests reproduced right-sided SI region pain. FADIR and labral scour maneuvers negative. DIFFERENTIAL DIAGNOSIS: 1. Mechanical low back pain 2. Spondylolysis 3. Sacroiliitis 4. Femoral acetabular impingement 5. Labral pathology 6. Avascular necrosis TESTS AND RESULTS: -Lumbar radiographs, year 2017: Normal. -Pelvic radiographs, 2018: Mild iliac-sided sclerosis and irregularity bilateral SIJs, more prominent on right. No fracture or dislocation. -Lumbar and pelvic MRI, 2018: Extensive subchondral marrow edema right SIJ; right SIJ effusion with changes suggesting enthesitis. Compatible with marked asymmetric sacroiliitis. Normal lumbar spine. Copyright © 2019 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.