Hamstring injury - grade BAC 2c with re-injury

Case contributed by Dr Henry Knipe


Sports injury. Posterior thigh pain.

Patient Data

Age: 30 years
Gender: Male

High signal along the distal lateral aspect of biceps femoris involving predominantly the distal myotendinous junction and to a less extent the myofascial fibers. Localized tendon slip/aponeurosis involvement with slight redundancy over 2.8 cm length. Less than 50% of the cross-sectional area. is involved. Increased T2 signal extending distally into the free tendon but not into the conjoint tendon. Craniocaudal extent of muscle fiber increased signal is 12.2 cm.

High intensity is noted around the posteromedial aspect of the knee, involving the pes anserine knee tendons, in particular the distal myotendinous junction of sartorius without extension into the free tendon.

Distal biceps femoris injury involving the distal myotendinous junction, myofascial fibres and localised intratendinous/aponeurosis involvement with slight redundancy over 2.8cm length. Distally extending increased T2 signal of the biceps femoris tendon. BAC grade 2c. 

A follow-up MRI was performed one month later. 

The muscle fiber T2 hyperintensity of the distal femoris muscle belly with a reduction in craniocaudal extent from 12 cm to 6 cm and involving ~50% cross-sectional area. 

The central tendon slip/aponeurosis is thickened and hyperintense but without redundancy. 

No new area of signal abnormality is seen.

Case Discussion

The return to play based on BAC grade 2c is typically 6-8 weeks but ended up being 12 weeks with re-injury of the proximal MTJ on the repeat scan. 

"C" denotes intratendinous involvement and is usually associated with longer return to play than other injury sites (i.e. myofascial or myotendinous) and there is a moderate association with type c injuries with increased re-injury.

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Case information

rID: 69741
Published: 21st Jul 2019
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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