Can a Clinical Examination Demonstrate Intramuscular Tendon Involvement in Acute Hamstring Injuries?

Abstract

Background:Involvement of the intramuscular (central) tendon in acute hamstring injuries, as detected on magnetic resonance imaging (MRI), may prolong recovery times. To date, it is unclear whether hamstring injuries exhibiting intramuscular tendon involvement can be identified though routine clinical examinations that assess flexibility and strength.Purpose:To test whether MRI-detected intramuscular tendon involvement could be identified by a clinical assessment of muscle strength and flexibility.Study Design:Case-control study; Level of evidence, 3.Methods:Participants were drawn from a multicenter randomized controlled trial on the effect of platelet-rich plasma in acute hamstring injuries. Clinical parameters assessed within 5 days of injury were active knee extension and passive straight-leg raise for hamstring flexibility and isometric knee flexion force with 15° and 90° of knee flexion. Also, 1.5-T MRI of the thigh was performed within 5 days of injury and was evaluated for the presence of different types of intramuscular tendon involvement. One-way analysis of variance was used to determine whether clinical parameters could discriminate injuries with intramuscular tendon involvement from those without such involvement.Results:A total of 74 acute hamstring injuries were included, with 52 (70.3%) injuries affecting the myotendinous junction. Injuries exhibiting intramuscular tendon discontinuity on MRI had an increased mean absolute flexibility deficit for active knee extension (20.4° ± 14.9° vs 10.7° ± 9.0°, respectively; P = .006) and decreased mean strength at 15° (62.2 ± 26.7 N vs 76.6 ± 22.5 N, respectively; P = .05) compared with injuries without intramuscular tendon discontinuity. Flexibility and strength showed major overlap and variance among injuries with and without intramuscular tendon involvement.Conclusion:Hamstring flexibility and strength cannot be used to discriminate the presence of intramuscular tendon involvement.

Imaging-detected acute muscle injuries in athletes participating in the Rio de Janeiro 2016 Summer Olympic Games

“…The sports medicine community should be aware of the relevant frequency of ‘c’ injuries as it may affect prognosis, as they are responsible for longer recovery times. We contend this highlights the usefulness of imaging services during major competitions such as the Olympic Games, as clinical examination cannot depict intramuscular tendon involvement in muscle injuries 31. However, we acknowledge the controversy relating to prognosis of these intramuscular hamstring tendon injuries.…”

Association of the British Athletic Muscle Injury Classification and anatomic location with return to full training and reinjury following hamstring injury in elite football

“…Given that clinical examination alone is unable to discriminate the presence of intramuscular tendon involvement, MRI is needed in professional sport. 10 The first prospective study of 70 HMIs by van der Made et al 11 has put this increased TRFT and reinjury association with intramuscular tendon involvement into doubt. Their study of athletes from various sports does not support the notion that injuries involving the tendon are significantly more serious.…”

“…Given that clinical examination alone is unable to discriminate the presence of intramuscular tendon involvement, MRI is needed in professional sport. 10 …”

Complete resolution of a hamstring intramuscular tendon injury on MRI is not necessary for a clinically successful return to play

“…The intramuscular tendon is defined as the part of the tendon to which the muscle fibres attach 4. At this time, we cannot clinically differentiate between a hamstring injury with or without intramuscular tendon involvement 9. However, MRI can be used to evaluate the intramuscular tendon and its direct structural changes after a muscle injury 4 5 10.…”