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INTRODUCTION: Very early stage lumbar spondylolysis is thought to be pre-fracture condition, which can be detected only by high signal change on MRI STIR images. Most of them don’t feel pain in daily life but sports activities. We had treated them with bracing and pausing sports activity in order to prevent from progressing to fracture. However, some of them didn't want to pause the sports and they continued sports withuout severe pain in short term. The purpose of this study was to compare the difference between the case of continuing sports and bracing for bone union.    

SUBJECTS and METHODS: We included 44 patients (36 boys and 8 girls), who were diagnosed as very early stage, and had unilateral or bilateral spondylolysis. Pseudo-bilateral (contralateral side was already terminal stage) patients were excluded in this study (average age: 14.5 years; range: 11–17 years). We have followed them for at least one year (Mean follow-up periods: 17 months; 12-32 months). Twelve patients continued sports activities (Group S). Remaining 32 patients (Group B) were instructed to put on soft brace, start exercise after the pain subsided and return to sports when MRI showed no signal change. We compared these two groups about bone union rate, recurrence rate and sports activity. We rated their sports activity into four ranks: 1) Excellent; no pain, full activities, 2) Good; occasional pain, full activities, 3) Fair; occasional pausing of sports activities due to low back pain, 4) Poor; pain on daily living, or quit sports.

RESULTS: In Group S, 4 out of 12 patients progressed to fracture. On the other hand ,in Group B, no one failed to union (p<0.01). Recurrence occurred 1 patient in addition to the above 4 patients in Group S, 5 in Group B (p=0.544). As to sports activity during  follow-up period, in Group S ,5 patients were rated “excellent”, 3 “good”, 5 ” fair”. In Group B, 25 “excellent”, 4 “good”, and 5 “fair” (p<0.01). Group B patients returned to sports within 4 week to 9 week, average of 6.5 week. Two patients in Group S resulted in bilateral spondylolysis. There was no significant difference as to age and level of affected laminae.

DISCUSSION: All patients in this study were able to return to sports with or without pain. However, even very early stage patients had risk of fracture if they continued sports, and had to pause their activity for a while because of pain. Therefore, we recommended all patients with very early stage spondylolysis to wear soft brace and to pause their sports activity until high signal change diminishing on MRI. As a result, it often can return faster. Not a few recurrences were observed regardless of the treatment. We believe that tightness of the body, such as thorax, shoulder girdle and hip joint, which is thought to be main causes of spondylolysis, had not been resolved in these cases.