Imaging:
The patient’s right shoulder was scanned with magnetic resonance imaging
(MRI) ten months prior to the injury because of chronic shoulder pain
lasting for two years. At that point, the range of motion was normal.
The MRI study showed intact rotator cuff, but degenerative cystic
changes and bone marrow edema at the supraspinatus insertion were
believed to result of chronic tractional forces. In addition, there were
edematous changes at the posteroinferior part of the glenoid joint and
the inferior glenohumeral ligament, probably due to a soft tissue injury
to the capsule. The protocol covered the right proximal latissimus dorsi
and the teres major in the coronal and sagittal planes, but there were
no pathological changes in that area.
The patient was scanned again ten months later, one week post-injury.
The MRI was performed as a standard shoulder protocol with a proton
density fat-saturated sequence (PD fat sat) in all three planes, coronal
T2 and sagittal T1. However, the technician added ten more axial slices
because of soft tissue edema seen below the shoulder joint, covering 12
cm in the craniocaudal direction (standard coverage in the current
shoulder MRI protocol is 9 cm) (Fig. 7a and b).
The scanner used for these two first MRI scans was an older model (1.5T
GE Optima MR 360).
Despite some movement artifacts, the MRI showed extensive hematoma and
edema in the soft tissues medial and anterior to the right proximal
humerus, below the level of the subscapularis muscle and the axillary
neurovascular bundle. The hematoma continued dorsally between the muscle
belly of the proximal triceps laterally and the latissimus dorsi
medially. The hematoma along the humerus measured 5 x 3 x 1.5 cm, and in
this area a completely ruptured and avulsed tendon of the latissimus
dorsi was identified, retracted 1.5-2.5 cm from its original attachment.
The teres major, normally having a shorter tendinous attachment than the
latissimus dorsi, was partially torn at its insertion at the proximal
humerus. There was extensive edema in the bellies of both muscles near
the musculotendinous junction, particularly in the latissimus dorsi,
which had extensive muscle fiber defects and intramuscular hematoma
(Fig. 8a-d).
The right shoulder was imaged again on three additional occasions with a
1.5T Siemens Aera MRI scanner:
- Seven weeks post-injury the hematoma was largely resorbed, but a small
amount of fluid along the now 4 cm retracted tendon of the latissimus
dorsi remained. The attachment of the muscles to the humerus was not
possible to identify, apart from probably a small remaining teres
major component. (Fig. 9a and 9b)
- Eleven weeks post-injury, some edema along the course of the teres
major and latissimus dorsi was seen, but no hematoma. The ruptured end
of the latissimus dorsi was, in both this and the previous scan,
somewhat thickened and maybe scarred, and there was slight edema in
the myotendinous junction (Fig. 10a-c). In contrast to the initial
post-traumatic MRI, a subdeltoid bursitis and a partial rupture of the
infraspinatus tendon attachment were visible.
- Thirty-eight weeks post-injury, the hematoma and edema were completely
resorbed. Some scar tissue had formed at the musculotendinous
junction. Even though parts of the muscle could now be seen connecting
to the humerus, the tendon and the distal muscle fibers were thin and
slender compared to the left side and the imaging before the injury
(Fig. 11a-d) (Fig. 12a and b (left side)).