From the Guidelines
Bicep tendon ruptures primarily occur due to a combination of sudden trauma and the culmination of repetitive stress and degeneration over time, with the most common causes including lifting heavy objects, falling onto an outstretched arm, or chronic overuse from repetitive overhead activities, as supported by recent studies such as 1.
The etiology of bicep tendon ruptures is multifactorial, involving both intrinsic and extrinsic factors. Intrinsic factors include age-related degeneration, as tendons naturally weaken with age, making people over 40 more susceptible to ruptures 1. Certain risk factors increase the likelihood of rupture, including smoking, steroid use (both corticosteroid injections and anabolic steroids), and conditions like tendinitis that cause inflammation and weakening of the tendon.
Some of the key points to consider in the context of bicep tendon ruptures include:
- The role of repetitive stress and degeneration, which can lead to partial or complete tears of the tendon 1.
- The importance of anatomical considerations, such as the position and mechanical stresses endured by the long head of the biceps at the shoulder, making it particularly vulnerable to injury 1.
- The impact of traumatic events, such as falls onto an outstretched arm, which can cause sudden and severe damage to the tendon 1.
- The potential for chronic overuse from repetitive overhead activities to contribute to the development of bicep tendon ruptures, as seen in athletes and individuals with occupations involving heavy lifting or overhead work 1.
In terms of diagnosis and assessment, MRI has been shown to be particularly useful in the evaluation of biceps tears, with improved sensitivity for the detection of partial tears of the biceps and triceps tendons 1. The use of nonstandard imaging views, such as the flexion-abduction-supination (FABS) MRI view, can also provide valuable information in the assessment of distal biceps tendon pathology 1.
From the Research
Causes of Bicep Tendon Ruptures
- Bicep tendon ruptures can occur due to various reasons, including eccentric extension load applied to the elbow, which typically happens in middle-aged males 2.
- The rupture can also be associated with rotator cuff tears, especially those involving the subscapularis, and tendinopathy of the long head of the biceps (LHB) tendon 3, 4.
- In some cases, bicep tendon ruptures can occur simultaneously with other injuries, such as acute rotator cuff tears, as seen in a strongman competitor who attempted a 300-pound overhead axle press 5.
Risk Factors and Mechanisms
- The exact mechanism of bicep tendon ruptures is not fully understood, but it is believed that inflammation of one tendon can lead to inflammation of another, increasing the risk of rupture 3.
- The long head of the biceps tendon is a known pain generator of the shoulder, and its disorders can cause anterior shoulder pain, especially in the presence of rotator cuff tears 6.
- The short head of the distal biceps may be a more powerful flexor, and the long head may be a more powerful supinator, which can contribute to the risk of rupture 2.
Types of Bicep Tendon Ruptures
- Distal bicep tendon ruptures typically occur at the radial tuberosity, where the tendon inserts, and can be diagnosed using physical examination maneuvers such as the biceps squeeze and hook tests, as well as imaging studies like MRI or ultrasound 2.
- Proximal biceps tendon ruptures can occur in association with rotator cuff tears and can be managed with tenotomy or tenodesis, which can provide effective pain relief 3, 4, 6.