Age / Sex : 14 / M

Age / Sex : 14 / Male

1) What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

* Send Application Answers to In Sook Lee, MD ([email protected])

Courtesy : Sung Gyu Moon, MD, Konkuk University Medical Center

Little Leaguer’s shoulder

Discussion

Findings:

Figure 1. Shoulder radiograph shows focal widening of the lateral aspect of the proximal humeral physis

Figure 2. Fat-saturated T2-W coronal MR image shows subtle widening and irregularity of humeral head physis, abnormal high signal in adjacent epiphysis and metaphysis interpreted as marrow edema.

Figure 3. Follow-up radiograph shows remodeling and normalization of the widened proximal humeral physis.

Diagnosis:  Little Leaguer’s shoulder (proximal humeral epiphysiolysis)

Discussion:

Little Leaguer’s shoulder is a stress-related injury to the proximal humeral physis encountered in adolescent athletes participating in a competitive sport which requires a repetitive throwing-type motion.

The radiographic findings of Little Leaguer’s shoulder are lateral physeal widening, lateral metaphyseal fragmentation, demineralization adjacent to the physis, and sclerosis of the proximal humeral metaphysic in patients with symptoms longer than 3 weeks. However, radiographs are usually normal if symptoms have been present less than 10 days.

MRI findings of Little Leaguer’s shoulder are physeal widening and bone marrow edema on both sides of the physis, adjacent periosteal edema and a small subchondral cyst adjacent to the physis.

The most commonly accepted theory to date suggests the mechanism involves repeated torque and possibly distraction on the proximal humeral physis. Torque refers to the external rotational stress applied to the proximal humeral physis during the act of throwing, which is greatest in the late cocking phase of the throwing motion. Distraction refers to the force exerted on the physis created by forward arm motion and the opposing proximally directed force generated by the rotator cuff and encountered at the point of ball release.

Treatment consists of relative rest from throwing for an average of 3 months, while using ice and analgesic medications for pain.

References:

1. Obembe OO, Gaskin CM, Taffoni MJ, Anderson MW. Little Leaguer's shoulder (proximal humeral epiphysiolysis): MRI findings in four boys. Pediatr Radiol. 2007 Sep;37(9):885-9.

2. Song JC, Lazarus ML, Song AP. MRI findings in Little Leaguer's shoulder. Skeletal Radiol. 2006 Feb;35(2):107-9.

3. Carson WG Jr, Gasser SI. Little Leaguer's shoulder. A report of 23 cases. Am J Sports Med. 1998 Jul-Aug;26(4):575-80.