Biceps tendinitis is inflammation of the tendon around the long head of the biceps muscle. Biceps tendinosis is caused by degeneration of the tendon from athletics requiring overhead motion or from the normal aging process.
Inflammation of the biceps tendon in the bicipital groove, which is known as primary biceps tendinitis, occurs in 5 percent of patients with biceps tendinitis. Biceps tendinitis and tendinosis are commonly accompanied by rotator cuff tears or SLAP (superior labrum anterior to posterior) lesions.
Patients with biceps tendinitis or tendinosis usually complain of a deep, throbbing ache in the anterior shoulder. Repetitive overhead motion of the arm initiates or exacerbates the symptoms. The most common isolated clinical finding in biceps tendinitis is bicipital groove point tenderness with the arm in 10 degrees of internal rotation.
Pathology of the biceps tendon is most often found in patients 18 to 35 years of age who are involved in sports, including throwing and contact sports, swimming, gymnastics, and martial arts. These patients often have secondary impingement of the biceps tendon, which may be caused by scapular instability, shoulder ligamentous instability, anterior capsule laxity, or posterior capsule tightness. Secondary impingement may also be caused by soft tissue labral tears or rotator cuff tears that expose the biceps tendon to the coracoacromial arch.
Biceps tendinitis may also refer to tendinosis, which is a syndrome of overuse and degeneration. Older patients (athletes older than 35 years or non-athletes older than 65 years) may have acute biceps tendinitis caused by sudden overuse, or biceps tendinosis caused by use over time.
Primary impingement syndrome is considered the most common cause of biceps tendinosis or tenosynovitis ( inflammation of the tendon sheath). Primary impingement is a mechanical impingement under the coracoacromial arch caused by bone spur formation of the acromion, an unfused acromial apophyses, or thickening of the coracoacromial ligament. It may also be caused by osteoarthritic spurs impinging on the bicipital groove.
Primary impingement in athletes older than 35 years leads to a higher incidence of rotator cuff tears than in younger athletes.