The goal of this study is to determine safety and tolerability of Losartan when used for treatment of an acute grade II or III hamstring strain and determining the effect of losartan on recovery of hamstring muscle function. Subjects will be adults age 18 and older with grade 2 or 3 hamstring injury who participate in greater than 100 hours per year in Level 1 or Level 2 athletics or have a similar activities or physical work load (e.g. military personnel). Subjects will undergo examination, MRI, and functional assessment before, during, and after 4 weeks of losartan (50mg QD) or placebo.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
TRIPLE
Enrollment
8
Cozaar
University of Pittsburgh
Pittsburgh, Pennsylvania, United States
Reported Effects of Losartan for Hamstring Injury for Safety and Tolerability
Directly related to specific aim 1- Side effects, safety, and tolerability will be monitored by measuring vital signs, lab values via blood work, and number of adverse events, serious adverse events, and patient reported side effects.
Time frame: 4 weeks
Recovery of Hamstring Muscle Function
For specific aim 2, hamstring muscle function of the injured leg was measured and compared to the contralateral leg using isometric hamstring force at 30, 60, and 90 degrees of knee flexion at 6 weeks and 6 months. Data are expressed as a Limb Symmetry Index (LSI), which is the percent force of the injured hamstring compared to the force of the non-injured hamstring muscle.
Time frame: 6 weeks; 6 months
Recovery of Hamstring Structure
For specific aim 2, recovery of hamstring structure was measured as the length of injury at 6 months as well as the change in proximal-distal length of injury from baseline to 6 month post-treatment MRI. Greater change in length represents greater healing.
Time frame: 6 months
Recovery of Hamstring Structure
For specific aim 2, hamstring structure was measured in terms of the volume of fibrosis at 6 month MRI, as such smaller volume of fibrosis represents greater healing of the hamstring muscle. Hamstring structure was also determined by comparing the change of pre-treatment volume of the injury on the baseline MRI to the volume of fibrosis on the 6 month MRI.
Time frame: 6 months
Return to Prior Level of Function
Return to prior level of function will be measured by the number of days from injury to full, unrestricted return to practice. This could have occurred at any timepoint after 6 weeks, so this did not necessarily occur at 12 months but it was monitored until the 12 month timepoint.
Time frame: 12 months
Recurrence of Injury
Number of recurrent injuries will be monitored during the duration of the subjects participation.
Time frame: 12 months
Recovery of Hamstring Structure
For specific aim 2, restoration of hamstring structure was operationally defined as the ratio of the volume of the injured to contralateral leg hamstring volume 6 months after injury 6 months post-injury. The percent of hamstring volume of the injured leg was expressed as a percentage of the hamstring volume of the contralateral normal leg. The difference in volume between the involved and non-involved hamstring muscles was divided by the non-involved hamstring muscle volume and multiplied by 100.
Time frame: 6 months
Return to Prior Level of Function
For specific aims 3 and 4, return to prior level of sports activity was measured by the Marx Activity Scale Score, which ranges from 0 to 16, with 16 being the highest level of sports activity. The frequency of participants who achieved the same or better Marx score at follow-up compared to baseline was calculated. Differences from baseline to each follow-up timepoint were calculated by subtracting the follow-up scores from baseline. Any difference of 0 or a negative number indicated the participants achieved the same level of sports activity or better. Positive differences indicated they did not return to their prior level of sports activity.
Time frame: 4 Weeks, 6 Weeks, 3 Months, 4 Months, 6 Months, 12 Months
Recovery of Hamstring Flexibility
For specific aim 2, hamstring muscle flexibility of the injured leg was measured and compared to the contralateral leg using the popliteal angle at 6 weeks and 6 months after randomization. The popliteal angle was measured with a goniometer. Recovery of hamstring flexibility was operationally defined as the difference in the popliteal angle between the contralateral normal leg minus the hamstring injured leg. Positive differences between the contralateral and injured leg indicated decreased hamstring flexibility.
Time frame: 6 weeks; 6 months
Recovery of Hamstring Muscle Function
For specific aim 2, hamstring muscle function of the injured leg was measured and compared to the contralateral leg using isometric hamstring force at 1 week, 2 weeks, 3 weeks, and 4 weeks. Data were expressed as a Limb Symmetry Index (LSI), which is the percent strength of the injured hamstring in comparison to the strength of the non-injured hamstring muscle.
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Time frame: 1 week; 2 weeks; 3 week; 4 weeks
Recovery of Hamstring Muscle Function
For specific aim 2, hamstring muscle function of the injured leg was measured on the Biodex and compared to the contralateral leg using isokinetic peak torque at 60 degrees and 180 degrees per second at 6 weeks and 6 months. Data were expressed as a Limb Symmetry Index (LSI), which is the percent peak torque of the injured hamstring compared to the peak torque of the non-injured hamstring muscle. The isokinetic testing was not consistently collected, so there are limited results to present at 6 months.
Time frame: 6 weeks, 6 months
Recovery of Hamstring Muscle Function
For specific aim 2, hamstring muscle function of the injured leg was measured on the Biodex and compared to the contralateral leg using isokinetic total hamstring work at 60 degrees per second and 180 degrees per second at 6 weeks and 6 months. Data were expressed as a Limb Symmetry Index (LSI), which is the percent total work of the injured hamstring compared to the total work of the non-injured hamstring muscle. The isokinetic testing was not consistently collected, so there are limited results to present at 6 months.
Time frame: 6 weeks, 6 months
Recovery of Hamstring Muscle Function
For specific aim 2, the ratio of hamstring peak torque to quadriceps peak torque at 60 degrees per second of the injured and non-injured legs were measured on the Biodex at 6 weeks. The isokinetic testing was not consistently collected, so there are limited results to present at 6 months.
Time frame: 6 weeks, 6 months
Recovery of Hamstring Muscle Function
For specific aim 2, the ratio of hamstring work in the last 3 repetitions to work in the first 3 repetitions at 180 degrees per second of the injured leg was measured on the Biodex at 6 weeks. The isokinetic testing was not consistently collected, so there are no results to present at 6 months.
Time frame: 6 weeks, 6 months