Thoracic outlet syndrome as a consequence of isolated atraumatic first rib fracture

Abstract

Neurogenic thoracic outlet syndrome (nTOS) resulting from an isolated first rib fracture is extremely infrequent. We report a case of performance limiting nTOS in a college athlete who was initially evaluated and treated for upper extremity ligamentous injury with only transient improvement. Subsequent noninvasive studies were consistent with TOS physiology and MRA showed a large hypertrophic callus on the first rib adjacent to the brachial plexus. With continued athletic limitations and radiographic findings consistent with TOS, surgical decompression was performed resulting in resolution of symptoms. Although apparent atraumatic isolated first rib fractures are infrequently reported etiologies for TOS in athletes, they are a reasonable consideration in this population with corresponding presentations.

Nontraumatic First Rib Fractures Secondary to Opposing Muscle Contractions

“…Instances of non-traumatic first rib fractures have been reported in athletes participating in swimming [1,2], baseball [3,4], football [5,6], soccer [3], tennis [6], powerlifting [7], rowing [8], lacrosse [9], martial arts [10,11], basketball [10], and surfing [12]. Many of these athletes participated in weight training for their respective sport [1,2,7].…”

“…Many of these athletes participated in weight training for their respective sport [1,2,7]. Athletes with non-traumatic first rib fractures frequently participate in sports with repetitive overhead arm movements or heading (soccer) movements [1,2,4,7,9,11,13].…”

“…One study on elite-level rowers found that rowers who had non-traumatic first rib fractures were more likely than their elite-level peers to have low bone mineral density, although their bone mineral density averages were equal to that of the general population [8]. Nontraumatic first rib fractures, resulting from either chronic stress over time [3,5,6,11] or from a sudden, forceful contraction of opposing muscles [1,4,6,9,11] are exceedingly rare. They tend to occur in adolescent or teenage athletes, perhaps due to bony maturation lagging behind muscle development [16].…”

“…On the inferior surface the serratus anterior and intercostal muscles attach. The scalene muscles pull superiorly and the serratus anterior and intercostals pull inferiorly on the first rib at these subclavian grooves [1,4,9,10,11]. Figure 3 Originally labeled Surfer's Rib in 1985, in the absence of direct sudden trauma, the first rib tends to fracture at the subclavian grooves, the weakest point, when these opposing muscles are both suddenly and forcefully engaged [12].…”

“…Horner's syndrome as a consequence of first rib fracture has been described, but never in a non-traumatic fracture case [13]. The most common complication is pseudarthrosis or non-union, however these patients, like the athlete in case 1, have generally been asymptomatic despite the pseudarthrosis and have returned to sport successfully [1,4,6,9,11,17]. This case series brings attention to an injury pattern in young athletes that though uncommon, is well-documented and could be overlooked on shoulder or chest x-ray without deliberate consideration.…”