Contents
Muscle belly lesion
Definition
- Pain which is felt at the mid-arm, in which the lesion itself may lie in the muscle belly, usually the lower half
Cause
- Often a result of a single excessive strain typically involved with lifting
Localization
- Posterior aspect of the muscle belly (most common)
- May be difficult to palpate
- At lower arm, at the musculotendinous junction
- At tenoperiosteal insertion at the tuberositas radii
Development
- Spontaneous cure may take 2 year
- Pain may continue indefinitely
- Especially with active patients who participate in sports or occupational manual labor
Indications
- Pain at the lower arm may indicate a musculotendinous junction lesion
- Pain at the anterior aspect of the elbow may indicate lesion to the tenoperiosteal insertion
Examination
- Resisted flexion is painful
- Resisted supination is painful
- When the lesion lies at tenoperiost at tuberositas radii
- Full passive pronation is painful in addition
- Palpation is negative
Distal biceps rupture
Definition
- Either a complete rupture or a partial rupture of the biceps tendon at the distal aspect of the muscle that usually occurs at the insertion of the tendon at the tuberositas radii
Occurrence
- Prevalence is around 2.55 per 100000 patient years 1
- More than 95% of patients are male
- Usually happens between 35-54 years of age2
Cause
- Occurs during excessive eccentric flexion force is applied to the arm towards a stretched position3
- Typically occurs during
- Weightlifting
- Wrestling
- Labor intensive jobs
Localization
- Usually at the insertion on the tuberositas radii
Risk factors
- Age
- Smoking
- Obesity
- Use of corticosteroids
- Over-exertion
- Musculotendinous ruptures are common injuries among athletes4,5
Development
- Pain can persist for weeks to months after the injury, pain will usually diminish faster if the tendon is completely torn
- Proximal biceps rupture patients generally recover with non-operative treatment and experience no long-term deficits in shoulder or elbow strength
- Distal biceps rupture, on the other hand, can cause persistent pain and forearm supination weakness6
- In complete distal biceps rupture
- Thetendon can retract significantly and later repair in chronic cases would be technically challenging. Therefore quick diagnosis of distal biceps rupture is critical, especially in a young active patient.
Indications
- Patient may complain of a sharp sudden pain in the elbow after an eccentric force is applied to the flexed elbow
- The patient may notice an audible ‘pop’ in the arm as it occurs
Observation
- Bruising and swelling may be present in the antecubital fossa
- Popeye sign may be present (bulge of the biceps in the mid-arm visible when patient flexes the arm), as the muscle is retracted to the upper arm and the distal tendon can be palpated
Examination
- Hook test
- Palpating and noticing an absence of the distal tendon of the biceps
- Position the patients arm in 90 degree of flexion and supination
- Hook the tendon underneath the skin
- When intact the examiner will be able to hook the index finger under the biceps tendon
- Test has high sensitivity and specificity7
- Resisted flexion - weakness
- Not necessarily good prediction as the brachialis will perform much of the force in flexion, and weakness can be hard to detect even though the biceps tendon is ruptured
Treatment
- Surgery is generally indicated for faster recovery and return to sports after complete distal biceps rupture8
- Surgery is also adviced to regain maximal strength of the forearm supination and to relieve pain in the antecubital fossa
References
- https://www.ncbi.nlm.nih.gov/books/NBK513235/
- https://pubmed.ncbi.nlm.nih.gov/26063401/
- https://www.ncbi.nlm.nih.gov/books/NBK513235/
- https://pubmed.ncbi.nlm.nih.gov/8947416/
- https://pubmed.ncbi.nlm.nih.gov/17548884/
- https://www.ncbi.nlm.nih.gov/books/NBK513235/
- https://pubmed.ncbi.nlm.nih.gov/17687121/
- https://pubmed.ncbi.nlm.nih.gov/30300219/