Rest Before Physical Therapy Is Not Necessary to Achieve Bony Healing of Lumbar Spondylolysis in Adolescent Athletes.

Background: Bony healing rates of spondylolysis on magnetic resonance imaging (MRI) are low, and it is unknown how timing of physical therapy (PT) affects healing. Hypothesis: It was hypothesized that (1) initiating PT immediately after spondylolysis diagnosis would not have a negative effect on the healing of active lumbar spondylolysis on MRI in adolescent athletes and (2) baseline characteristics, as well as follow-up measures of pain and function, would not be associated with healing on 3-month MRI. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: This multicenter trial randomized adolescent athletes with lumbar spondylolysis to Immediate PT or Rest Before PT. A blinded radiologist assessed changes in edema and lysis on the initial and 3-month MRIs to determine healing. No rigid bracing was used in any participant. Results: A total of 53 participants (25 in the Immediate PT group and 28 in the Rest Before PT group) completed a baseline and 3-month follow-up MRI. At 3 months, 81% of participants demonstrated healing on MRI, 8% demonstrated no change, and 11% demonstrated worsened findings. Participants in the Immediate PT group were not more likely to have worse findings on the 3-month MRI than the Rest Before PT group ( Conclusion: Prolonged rest may not be necessary to promote healing on MRI in adolescent athletes with lumbar spondylolysis. PT can begin immediately without negatively affecting healing of spondylolysis on MRI. Registration: NCT05505981.