Clinical Scenario: Hamstring strains are common athletic injuries, with a high-recurrence rate (34%). Recently, platelet-rich plasma (PRP) injections have gained popularity as a potential treatment option to accelerate healing of hamstring injury. Focused Clinical Question: Does the combination of PRP injection and rehabilitation decrease recovery time of acute hamstring injury as compared to rehabilitation alone in college athletes? Summary of Key Findings: A literature search resulted in 3 randomized controlled trials. One study showed benefits in various outcome measures with PRP, compared to rehabilitation alone, while 2 showed no benefits. One study reported improved pain, ultrasonography regenerative indications, and recovery time with PRP injection following acute hamstring injury; however, larger studies have shown no benefits. The literature demonstrates conflicting evidence regarding benefits of PRP injections in hamstring injuries. Clinical Bottom Line: At this time, PRP injections cannot be recommended as having value for hamstring injuries, compared to rehabilitation alone. Strength of Recommendation: Due to inconsistent or limited quality patient-oriented evidence in existing literature, the strength of this recommendation is grade B, based on the strength of recommendation taxonomy.
Mary Lynn Manduca and Stephen J. Straub
Timothy J. Demchak, Stephen J. Straub and Lennart D. Johns
Ultrasound heating rates are known to differ between various manufacturers; it is unknown whether this difference exists within a manufacturer.
Determine if intramuscular heating differences exist between transducers from the same manufacturer.
3 × 10 repeated measures. Independent variables were Transducer (A, B, and C) and Time (10-min time points during the treatment).
Twelve volunteers (M = 4, F = 8; age: 23 ± 4 years; calf-girth: 37.94 ± 4.16 cm; calf-skinfold: 27 ± 17 mm).
Three 10-min 1MHz continuous ultrasound treatments performed at an intensity of 1.2 W/cm2, over an area 2x transducer.
Main Outcome Measures:
Calf temperature increase.
Heating curve generated for each transducer were significantly different (P = .034) but the overall temperature increases following 10 minutes of treatment were within 0.1°C (F = 1.023 P = .573).
Heating curves differ between transducers from the same manufacturer but peak heating at 10 minutes was similar.