British athletics muscle injury classification: a new grading system

Abstract

The commonly used muscle injury grading systems based on three grades of injury, representing minor, moderate and complete injuries to the muscle, are lacking in diagnostic accuracy and provide limited prognostic information to the clinician. In recent years, there have been a number of proposals for alternative grading systems. While there is recent evidence regarding the prognostic features of muscle injuries, this evidence has not often been incorporated into the grading proposals. The British Athletics Muscle Injury Classification proposes a new system, based on the available evidence, which should provide a sound diagnostic base for therapeutic decision-making and prognostication. Injuries are graded 0–4 based on MRI features, with Grades 1–4 including an additional suffix ‘a’, ‘b’ or ‘c’ if the injury is ‘myofascial’, ‘musculo-tendinous’ or ‘intratendinous’. Retrospective and prospective studies in elite track and field athletes are underway to validate the classification for use in hamstring muscle injury management. It is intended that this grading system can provide a suitable diagnostic framework for enhanced clinical decision-making in the management of muscle injuries and assist with future research to inform the development of improved prevention and management strategies.

MR Imaging of Muscle Trauma: Anatomy, Biomechanics, Pathophysiology, and Imaging Appearance

“…The MTJ is located at a variable distance from the bone, and the tendinous portion located between the bone and the MTJ is referred to as the "free tendon" (25). Muscles with short free tendons, such as the gluteus maximus and deltoid, appear to insert virtually directly on the bone, whereas muscles such as the rectus femoris, biceps brachii, and plantaris have free tendons several centimeters in length (Fig 6).…”

“…This system also assigns a letter to each injury grade on the basis of whether the injury is localized to the epimysium/fascia, MTJ, or tendon, as recovery times are shortest for epimysial strain and longest if there is frank tendon damage (25) (Fig 38).…”

Perivascular Adductor Longus muscle injury: Ultrasound and Magnetic Resonance Imaging findings

“…The protocol included traversal (axial), sagittal and coronal T1-weighted spin-echo (T1w), fat-suppressed T2-weighted spin-echo (T2w) and short tau inversion recovery (STIR) sequences 20 . According to the most recent MRI-based classification systems 22,23 , the presence of isolated intramuscular oedema was indicative of a minor lesion, while the presence of perifascial liquid and/or intramuscular haematoma typically indicated a more severe injury. MRI was especially useful to accurately identify the site of injury (myofascial, myotendinous junction, intratendinous or a combination of these) 20,22,23 .…”

“…MRI investigation: routine protocol, specific requirements and guidelines MRI was considered the gold standard to confirm the presence of muscle injuries that were clinically and ultrasonographically suspected 19,[21][22][23][24] . The protocol included traversal (axial), sagittal and coronal T1-weighted spin-echo (T1w), fat-suppressed T2-weighted spin-echo (T2w) and short tau inversion recovery (STIR) sequences 20 .…”

Hip Imaging in Athletes: Sports Imaging Series

“…A more comprehensive MR imaging classification system for hamstring injuries has been recently proposed (the British Athletics Muscle Injury Classification) (162). With this new classification system, injuries are classified not only with respect to extent but also location of injury within the muscle (myofascial, myotendinous, intratendinous) (162).…”