Stress Fractures of Pars Interarticularis in Adolescent Athletes a Classification System with MRI and CT Enabling Evaluation of The Healing Process

Introduction: The purpose of this study was to evaluate healing frequency in different stages of stress reactions in the Pars Interarticularis (PI) using a classification system with MRI and CT. The intervention was 3-month rest from physical activity, without a brace, with the exception of activities of daily living. Materials & Method: Twelve adolescent athletes with different stages of Spondolysis were included in the study. They had pathology in the Pars Interarticularis and were clinically examined with MRI and CT 3-6 weeks after debut of Low Back Pain (LBP) and re-evaluated after 3 months intervention with rest from physical activity. Results: A combination of MRI and CT scanning to investigate suspected injuries to Pars Interarticularis in adolescent athletes revealed 6 different stages of Spondolysis that ranged from marrow oedema to pseudoarthrosis. After 3 months of rest from physical activity the early stages of Pars Interarticularis injuries healed significantly better than the later stages with rest from physical activity. Conclusion: The combination of MRI and CT revealed 6 stages of stress reactions instead of 4 as in Hollenberg’s staging with MRI only. In the 3 earliest stages, of these 6, rest from physical activity for 3 months can heal the stress reaction. Keywords: Low Back Pain; Oedema; Pseudoarthrosis; Spondylolysi