Neurovascular injuries to the shoulder

A systematic review on posterior circumflex humeral artery pathology: sports and professions at risk and associated risk factors

INTRODUCTION

Posterior circumflex humeral artery (PCHA) aneurysm formation and thrombosis as overuse injury in the dominant shoulder can result in ischemia of the forearm, hand and digits due to arterial embolisms. Increased awareness among physicians is necessary as PCHA pathology (PCHAP) might be underdiagnosed. Knowledge of sports and professions at risk and risk-factors for obtaining PCHAP is essential for the development of future preventive measures. This study aims to identify sports and professions at risk as well as risk factors for PCHAP.

EVIDENCE ACQUISITION

The databases of MEDLINE, EMBASE, BIOSIS, CINAHL and SPORTDiscus were systematically searched.

EVIDENCE SYNTHESIS

Twenty-seven papers fulfilled the inclusion criteria and described 67 patients with PCHAP involved in seven sports and three professions. The sports (number of cases) were volleyball (41), baseball (13), swimming (1), tennis (3), American football (2), canoeing (1) and yoga (1) (2 unknown). The professions included a baseball coach, a circus trapeze artist and a mechanic. Apart from expert opinions, no studies have identified risk factors for PCHAP. An anatomic variation of the PCHA origin is suggested to be protective for PCHAP.

CONCLUSIONS

PCHAP is reported in seven overhead sports and three professions. No risk factors for PCHAP were identified. An anatomic variant of the PCHA origin was found to be a potential protective factor for PCHAP. Physicians should be cautious for distal embolization as a result of PCHAP in athletes and workers, both adult and adolescent, involved in repetitive powerful overhead movements.

Upper extremity blood flow changes in professional baseball pitchers between two consecutive seasons

BACKGROUND

Because of the tremendous forces produced and the repetitive nature of baseball, players have shown various shoulder adaptations in strength and range of motion. However, no research has identified whether alterations occur in the blood flow to the dominant arm among competitive baseball players.

METHODS

Twenty professional baseball pitchers and 16 position players participated. Measurements were taken on day 1 of 2 consecutive spring training seasons. Diagnostic ultrasound was used to measure blood flow of the throwing arm brachial artery. These measurements were taken in a standing position with the test arm resting at the participant's side and again with the test arm in a provocative shoulder position. Separate 1-way analyses of variance were conducted to compare blood flow between seasons (P < .05).

RESULTS

In a resting position, the blood flow of the pitchers did not change from 1 year to the next (P = .48). However, blood flow of the pitchers in the provocative position significantly decreased after the first year (P = .009). The position players did not have any significant changes in blood flow for either arm position (P > .11).

CONCLUSIONS

In a provocative shoulder position, the blood flow of pitchers significantly decreased after 1 competitive baseball season. These results indicate that after a competitive season, the blood flow to the upper extremity of pitchers may be compromised.

The effects of shoulder laxity on upper extremity blood flow in professional baseball pitchers

BACKGROUND

The repetitive overhand throwing can potentially cause physiologic or pathologic changes in musculoskeletal and vascular structures. The purpose of this study was to investigate the effects of throwing on upper extremity arterial blood flow before and after a controlled pitching session. The hypothesis is that pitchers with physical signs of shoulder laxity would demonstrate differential changes in upper extremity blood flow as compared to those without laxity.

METHODS

Eighteen professional male pitchers underwent a detailed shoulder physical evaluation, followed by a wrist/brachial index (WBI) vascular exam and a vascular ultrasound examination before and after a controlled throwing session.

RESULTS

Following a 50-pitch workout, the WBI was significantly lower (0.79-0.86) in pitchers with laxity on exam versus no laxity (P < .05). For all pitchers, the average arterial volume flow increased from 234 ml/min to 482 ml/min after 50 pitches. Pitchers without physical signs of laxity had an average arterial volume flow increase of 115%, while the pitchers with laxity signs increased 35%.

CONCLUSION

This study demonstrated a statistically significant decrease in arterial blood flow in the laxity group compared to the nonlaxity throwers.

Case reports: unusual cause of shoulder pain in a collegiate baseball player

The objective of reporting this case was to introduce a unique cause of shoulder pain in a high-level Division I NCAA collegiate baseball player. Various neurovascular causes of shoulder pain have been described in the overhead athlete, including quadrilateral space syndrome, thoracic outlet syndrome, effort thrombosis, and suprascapular nerve entrapment. All of these syndromes are uncommon and frequently are missed as a result of their rarity and the need for specialized tests to confirm the diagnosis. This pitcher presented with nonspecific posterior shoulder pain that was so severe he could not throw more than 50 feet. Eventually, intermittent axillary artery compression with the arm in abduction resulting from hypertrophy of the pectoralis minor and scalene muscles was documented by performing arteriography with the arm in 120 degrees abduction. MRI-MR angiographic evaluation revealed no anatomic abnormalities. The patient was treated successfully with a nonoperative rehabilitation program and after 6 months was able to successfully compete at the same level without pain.

Neurovascular injuries to the athlete's shoulder: part II

Athletes are at particular risk of compromise of the neurovascular structures of the shoulder-specifically, neurovascular conditions distal to the brachial plexus. These conditions include thoracic outlet syndrome, axillary artery occlusion, effort thrombosis, suprascapular nerve entrapment, quadrilateral space syndrome, and complex regional pain syndrome. When diagnosed properly and in a timely fashion, function of the limb can be preserved. To accomplish this, the physician must possess a detailed understanding of the various clinical presentations, diagnostic techniques, and treatment options.

Acrobatic vascular disease

Athletes performing repetitive movements can develop arterial injuries. These are uncommon. We present a case of bilateral subclavian/axillary artery stenosis in a female patient referred to the rapid access chest pain clinic with a presumptive diagnosis of angina. Her symptoms were related to limb ischemia rather than cardiac insufficiency. Detailed history from this patient revealed that she had spent 8 years working as an acrobat being swung by the arms twice daily during performances.

Surgical anatomy of the axillary nerve within the quadrangular space

Object. There is a paucity of literature regarding the surgical anatomy of the quadrangular space (QS), which is a potential site of entrapment for the axillary nerve. Muscle hypertrophy of this geometrical area and fascial bands within it have been implicated in compression of the axillary nerve.

Methods. Fifteen human cadavers (30 sides) were dissected for this study. Measurements of the QS and its contents were made. The mean height of this space was 2.5 cm and the mean width 2.5 cm; its mean depth was 1.5 cm. The axillary nerve was always the most superior structure in the space, and in all cases the nerve and artery hugged the surgical neck of the humerus just superior to the origin of the lateral head of the triceps brachii muscle. This arrangement placed the axillary nerve in the upper lateral portion of the QS in all cadaveric specimens. The nerve branched into its muscular components within this space in 10 sides (33%) and posterior to it in 20 sides (66%). The cutaneous component of the axillary nerve branched from the main trunk of the nerve posterior to the QS in all specimens. Fascial bands were found in this space in 27 (90%) of 30 sides.

Conclusions. Knowledge of the anatomy of the QS may aid the surgeon who wishes to explore and decompress the axillary nerve within this geometrical confine.

Embolisation of a traumatic aneurysm of the posterior circumflex humeral artery in a volleyball player

Repetitive minor vascular injuries caused by physical activity in athletes may lead to ischaemia of the upper extremities. In volleyball players in particular, traumatic aneurysm of the posterior circumflex humeral artery has been reported to be a cause of ischaemia of the arm and hand. Such an aneurysm is described here; it was treated successfully with endovascular embolisation.

Emergency department evaluation and treatment of the shoulder and humerus

The shoulder girdle is a versatile anatomic structure with a wide range of mobility and function. Its soft tissue and skeletal components are subject to a variety of injuries spanning from overuse syndromes to acute trauma. This article reviews the key historical and physical examination techniques of the shoulder, and special attention is paid to proper imaging in the emergency department, which aids in the diagnosis of specific disorders. This article also reviews the various therapeutic options, including surgery.

Upper extremity blood flow in collegiate and high school baseball pitchers A preliminary report

The arterial and venous volume blood flow in the dominant and nondominant upper extremities of five male pitchers, ages 16 to 21, was measured using color flow duplex ultrasound. Blood-flow measurements were obtained at baseline, after warm-up, and after each sequence of 20 pitches until 100 pitches were thrown. Blood flow was additionally determined 1 hour after the last pitch. The velocity of each pitch was recorded with a speed gun. Anthropomorphic measurements of the upper extremity were obtained at baseline and immediately after Pitch 100 using a standard measuring tape. The highest average arterial volume flow in the pitching arm occurred after 40 pitches, reaching a peak of 549 ml/min (56% increase from baseline). Thereafter, the average arterial blood flow steadily declined, reaching an average of 402 ml/min after the 100th pitch (14% increase from baseline). In contrast, the arterial blood flow in the nonpitching arm increased only slightly from baseline, reaching a maximal volume flow of 448 ml/min immediately after the warm-up period (10% increase from baseline). The volume flow then persistently fell to a level 30% below baseline after the 100th pitch. Although this small pilot study does not demonstrate causation between a decline in pitching performance and arterial blood flow, it suggests arterial flow in the dominant extremity falls as the pitch count increases.

Diagnosis and treatment of rotator cuff tears in the emergency department

This article will review the diagnosis and management of rotator cuff tears in the emergency department. Rotator cuff disease is a common source of shoulder pain. It encompasses a wide range of pathology of the rotator cuff tendons. These lesions can include impingement or tendinitis, and may progress to rupture of the tendons. In considering the emergency department management of cuff tears, it is useful to classify patients by the mechanism of their injury. Proper classification of patients requires a careful history and physical examination. Interpretation of these data is based on an understanding of the entire range of pathology that can affect the tendons of the rotator cuff.