Mechanism of injury (M)
Locations of injury (L)
Grading of severity (G)
Number of muscle reinjuries (R)
Hamstrings direct injuries
T (direct)
P Injury located in the proximal third of the muscle belly
0–3
0 First episode
1 First reinjury
2 Second reinjury and so on
M Injury located in the middle third of the muscle belly
D Injury located in the distal third of the muscle belly
Hamstrings indirect injuries
I (indirect) plus subindex s for stretching type or subindex p for sprinting type
P Injury located in the proximal third of the muscle belly. The second letter is a subindex p or d to describe the injury relation with the proximal or distal MTJ, respectively
0–3
0 First episode
1 First reinjury
2 Second reinjury and so on
M Injury located in the middle third of the muscle belly, plus the corresponding subindex
D Injury located in the distal third of the muscle belly, plus the corresponding subindex
Negative MRI injuries (location is pain related)
N plus subindex s for indirect injuries stretching type or subindex p for sprinting type
N p proximal third injury
0–3
0 First episode
1 First reinjury
2 Second reinjury and so on
N m middle third injury
N d distal third injury
Grading of injury severity
0
When codifying indirect injuries with clinical suspicion but negative MRI, grade 0 injury is codified. In these cases the second letter describes the pain locations in the muscle belly
1
Hyperintense muscle fiber edema without intramuscular hemorrhage or architectural distortion (fiber architecture and pennation angle preserved). Edema pattern: interstitial hyperintensity with feathery distribution on FSPD or T2 FSE+ STIR images
2
Hyperintense muscle fibers and/or peritendon edema with minor muscle fiber architectural distortion (fiber blurring and/or pennation angle distortion) ± minor intermuscular hemorrhage, but no quantifiable gap between fibers. Edema pattern, same as for grade 1
3
Any quantifiable gap between fibers in craniocaudal or axial planes. Hyperintense focal defect with partial retraction of muscle fiber ± intermuscular hemorrhage. The gap between fibers at the injury’s maximal area in an axial plane of the affected muscle belly should be documented. The exact % CSA should be documented as a subindex to the grade
r
When codifying an intra-tendon injury or an injury affecting the MTJ or intramuscular tendon showing disruption/retraction or loss of tension exists (gap), a superscript (r) should be added to the grade
The best classification should be reproducible, capable of distinguishing between different categories, easy to remember, and related to the prognosis.
33.2 New Proposal “MLG-R”
Our proposal describes the injury based on mechanism “M,” location “L,” and its relation with the muscle tendon junction (MTJ) and connective tissue evaluation, grading by imaging description “G,” and, finally, reinjury “R.” This classification system is summarized in Tables 33.2, 33.3, and 33.4. Imaging diagnosis techniques, both MRI and US, are essential in correctly describing the injury [36]. US is capable of providing a description of the location [37, 38], but the best description will be based on the MRI features of the muscle injury [39–41]. This classification has been designed for hamstrings because it is the most frequently injured muscle group in almost all sports worldwide. In the future, another muscles and special situations must be considered. The specific muscle that has been injured should also be named.
Table 33.2
Summary of the “MLG-R” classification system (part 1)
Mechanism | Location | Grade | Reinjury |
|---|---|---|---|
T (direct) | p Injury located at the proximal third of the muscle belly | ||
m Injury located at the middle third of the muscle belly | |||
d Injury located at the distal third of the muscle belly | |||
Hamstrings indirect injuries | |||
I plus subindex S for Indirect injuries Stretching type, or subindex P for Sprinting type. | P Injury located at the proximal third of the muscle belly. The second letter has a subindex p or d describe the injury relation with the proximal or distal MTJ. | ||
M Injury located at the middle third of the muscle belly, plus the corresponding subindex. | R0 1st episode R1 1st reinjury R2 2nd reinjury ..and so on. | ||
D Injury located at the distal third of the muscle belly, plus the corresponding subindex. | See below | ||
Rectus Famoris indirect injuries | |||
I Indirect injuries | P Injury located at the proximal third of the muscle belly. The second letter has a subindex P or D to describe the injury relation with the proximal or distal MTJ. | ||
M Injury located at the middle third of the muscle belly, plus the corresponding subindex. | |||
D Injury located at the distal third of the muscle belly, plus the corresponding subindex. | |||
Table 33.3
Summary of the “MLG-R” classification system (part 2)
 | |
|---|---|
• 0 When codifying indirect injuries with clinical suspicion but negative MRI, we will codify a Grade 0 injury. In this cases the second letter will describe the pain locations at the muscle belly. • 1 Hyperintense oedema without intramuscular haemorrhage or architectural distortion (fibres architecture and penation angle preserved). Oedema pattern: interstitial hyperintensity with f eathery distribution on FSPD or T2 FSE+ STIR images. • 2 Hyperintense oedema with small +/– intramuscular/intermuscular haemorrhage or architectural distortion (fibres architecture or penation angle distortion); but no quantifiable gap between fibres. Oedema pattern: interstitial hyperintensity plus feathery distribution on FSPD or T2 FSE+ STIR images. • 3 Hyperintense hemorrhage with quantifiable gap between fibres in craniocaudal or axial planes. Interstitial hyperintensity with focal hyperintensity representing hemorrhage in muscle belly +/– intramuscular fluid. Hyperintense focal defect with partial retraction of muscle fibers. We will record the gap between fibers at the injury’s maximal area, in an axial plane of the affected muscle belly. • When codifying an injury affecting the MTJ or intramuscular tendon showing disruption/retraction or loss of tension exist (gap), we have to add a superscript (r) to the grade.
Related posts: Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
Get Clinical Tree app for offline access
| |
