Muscle Contusions: Extrinsic Muscle Lesions

Classification

Active flexion ROM

Walking

Minor

>90°

Normal

Moderate

45–90°

Antalgic

Severe

<45°

Severe limping

11.4.1 Minor Muscle Contusion

The athlete may or may not remember the incident and usually can keep playing. Soreness increases after effort or the following morning. During clinical examination, the articular active range of motion related to the injured muscle is limited from 5 to 20 %. Local palpation is tender and a minimal loss of force is found during contraction testing [9]. Imaging shows a diffuse swelling, but no structural damage or dilacerations of muscle fibers and no hematoma [10].

11.4.2 Moderate Muscle Contusion

The athlete remembers the incident but can continue playing despite increasing stiffness during breaks (half time). During clinical examination, the athlete is limping; the articular active range of motion linked to the injured muscle is limited to 20–50 %. Palpation and resisted contraction are painful and associated with loss of force [9]. Imaging shows damage to the muscular tissue of less than 50 % of the axial surface of the muscle with a non-collected spreading hematoma [10].

11.4.3 Severe Muscle Contusion

The athlete remembers the impact very well and usually had to stop playing. Bleeding progresses quickly and is difficult to control. Clinical examination reveals a deformity of the muscle with an increased volume sometimes associated with delayed ecchymosis. Palpation is very painful. Walking is difficult. The articular active range of motion related to the injured muscle is limited by more than 50 %. Loss of force is important [9]. Imaging shows damage to more than 50 % of the axial surface with a collected hematoma. The hematoma can be either intramuscular or perimuscular if the peripheral aponeurosis is torn [10].

11.5 Radiological Strategies

11.5.1 Diagnostic

Immediately after the injury, X-ray can be used if an associated bony lesion or other injuries are suspected.

Real time ultrasound seems to be the most used due to its accessibility, its cost and the ability to perform a guided puncture of any collected hematoma. The examination should be performed after at least 48 h [10] to avoid underestimating the seriousness of the contusion and to allow blood collection (Figs. 11.1–11.5). Ultrasound allows precise diagnosis of the injured muscle, measurement of the lesion size and a calculation of the axial injured surface. The examination should look carefully at the superficial aponeurosis. In some cases, local hematoma will be limited to the sub-cutaneous tissue without a muscle tissue lesion; the superficial aponeurosis will then be intact and show a concave shape. With a lesion of the aponeurosis, pain is inversely proportional to the size of the lesion. Small tears are very painful; large lesions allow the hematoma to drain and decrease intramuscular pressure. In the rare case of an isolated lesion, comparison with the non-injured side will show localized thickening inducing vascular and neural pain.

Fig. 11.1

Transverse ultrasound image at the mid third of the anterior thigh shows moderate diffuse hyperechoic signal within the left rectus femoris muscle (>50 % of muscle surface area). The normal right rectus femoris muscle is shown for comparison. RF rectus femoris, VI vastus intermedius, fe femur

Fig. 11.2

Transverse ultrasound image at the mid third of the anterior thigh shows severe heterogeneous hyperechoic signal with anechoic area signaling a hematoma at the rectus femoris (>50 % of muscle surface area). RF rectus femoris, VI vastus intermedius

Fig. 11.3

Longitudinal ultrasound image at the mid third of the anterior thigh shows chronic hyperechoic and organized fibrotic tissue (arrows) between the rectus femoris and vastus intermedius muscles aponeurosis from chronic hematoma. RF rectus femoris, VI vastus intermedius

Fig. 11.4

Transverse ultrasound image at the mid third of anterior thigh shows severe anechoic signal within the vastus intermedius due to collected hematoma. DF rectus femoris, VI vastus intermedius, VL vastus lateralis, VM vastus medialis, fe femur

Fig. 11.5

Longitudinal ultrasound image at the mid third of the anterior thigh shows severe anechoic signal within the vastus intermedius due to a collected hematoma. RF rectus femoris, VI vastus intermedius

If the muscle lesion is deep (e.g. the soleus) or ultrasound is not available, MRI remains the gold standard. With MRI the size of the lesion, local edema, the hematoma and muscle tissue damage can be investigated (Figs. 11.6–11.9).

Fig. 11.6

Axial fat-suppressed T2-weighted MRI of right mid-calf shows severe muscle contusion of the gastrocnemius lateralis associated with rupture of the deep and superficial aponeurosis

Fig. 11.7

Axial fat-suppressed T2-weighted MRI of right proximal thigh shows severe muscle contusion of the vastus intermedius

Fig. 11.8

Axial fat-suppressed T2-weighted MRI of right mid-thigh discloses moderate muscle contusion of the vastus lateralis without aponeurosis rupture

Fig. 11.9

Axial fat-suppressed T2-weighted MRI of left mid-thigh shows combined severe muscle contusion of the vastus lateralis and vastus intermedius

11.5.2 Follow-Up

The healing process can be followed with real time ultrasound. Doppler signal activity, initially localized on the central zone of the lesion, will progressively migrate to the peripheral zone and slowly disappear.

A few days after hematoma evacuation, an ultrasound examination should be undertaken to rule out any recurrent bleeding.

MRI is the most sensitive examination to follow muscle healing Figure 11.10. Hematoma will decrease after 10 days [