Relationship Between the Pain Intensity at the Time of the Hamstring Muscle Injury and the Hyperintense T2 Weighted Volume of the Hamstring Muscle Lesion Measured by MRI

Objectives:The primary objective of this study was to analyze the correlation between the pain experienced at the time of a hamstring muscle injury and the hyperintense T2 weighted volume of the lesion measured on MRI. The secondary objectives were to analyze the differences in this pain with the lesion grade and the hamstring muscle head involved.Design:We performed a retrospective analysis of the data collected in a prospective, multicenter, noninterventional cohort study (HAMMER).Patients:A total of 61 patients were included in this analysis.Interventions:Patients with suspected hamstring muscle injury had an MRI after the injury.Main outcomes measures:They were evaluated for their pain intensity experienced at the time of injury with a Numeric Pain Rating Scale (NPRS) from 0 to 10.Results:There was a significant but weak correlation between the pain experienced at the time of hamstring muscle injury and the hyperintense T2 weighted volume (r = 0.287; P = 0.025). There were no significant differences in the pain according to the lesion grade (F(3,57) = 0.982; P = 0.408) nor according to the muscle involved (F(3,57) = 1.013; P = 0.394).Conclusions:Pain at the time of injury seemed to be weakly correlated with the extent of muscle lesion at medical imaging. Pain at the time of injury alone seems not enough to give us a clinical meaningful indication of the MRI hyperintense T2 weighted volume.