Bilateral ultrasound findings in patients with unilateral subacromial pain syndrome.

BACKGROUND

Subacromial pain syndrome is a common musculoskeletal shoulder problem. The accuracy of clinical tests is low and techniques such as ultrasound and magnetic resonance imaging have been added to set up a diagnosis. Previous researchers have usually only examined the symptomatic shoulder. However, there might be similar findings in the asymptomatic shoulder.

OBJECTIVE

The aim of the present study was to investigate the prevalence of structural abnormalities of both shoulders in patients with clinically diagnosed unilateral subacromial pain syndrome using diagnostic ultrasound.

METHODS

Bilateral ultrasound examinations were performed in 115 consecutive patients, 54 men and 61 women. The patients were recruited from primary care centers in the area of Stockholm, Sweden.

RESULTS

Abnormal ultrasound findings were found in both shoulders and increased with age (p = .0004). Bursitis was the most common ultrasound finding and significantly more prevalent in the symptomatic shoulder compared to the asymptomatic shoulder (90%:74%; p = .0021), though 73% of the bursitis were bilateral. Supraspinatus is the most vulnerable tendon of the rotator cuff in both shoulders. In terms of partial-thickness tears and tendinosis, the tendon was affected more commonly in the symptomatic shoulder compared to the asymptomatic shoulder (30%:14%: 14%; p = .0026) and (24%:10%; p = .0054), respectively, but for calcification no significant difference between the shoulders was found (18%:12%; 0.1988).

CONCLUSION

Ultrasound detected shoulder abnormalities were present in both symptomatic and asymptomatic shoulders. Bursitis and partial-thickness tears were more common in the affected shoulder when compared to the unaffected shoulder. Ultrasound as well as clinical examination findings and patient´s history should be taken into consideration when diagnosing patients with subacromial pain syndrome.