e686 Discovery of a novel articular cartilage skeletal stem cell

e687 Diagnostic Value of Ultrasound Imaging for Tibial Stress Fractures

e688 Isolated Medial Patellofemoral Ligament Reconstruction With and Without Bony Patellar Fixation In Young Patients - A Multicenter Comparison of Three Operative Techniques

e689 Effects of Obesity in Patient Reported Outcomes After Hip Arthroscopy

e690 Risk Factors for Not Achieving the Minimal Important Change of Patient Reported Outcomes at 2 Years Following ACL Reconstruction: An analysis from the UK National Ligament Registry