Related Experiment Video
Updated: Nov 15, 2025
Measuring 3D In-vivo Shoulder Kinematics using Biplanar Videoradiography
Published on: March 12, 2021
Humeral lesser tuberosity avulsion fractures - magnetic resonance imaging characteristics in the pediatric population
Maria A Bedoya1,2, Christian A Barrera3, Jenny T Bencardino4
1Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce St., Philadelphia, PA, 19104, USA. bedoya3@yahoo.com.
Insights
Lesser tuberosity avulsion fractures in children are rare, difficult-to-diagnose injuries. Magnetic resonance imaging (MRI) is crucial for identifying these fractures, often missed on initial X-rays, enabling prompt treatment.
Area of Science:
- Pediatric Orthopedics
- Radiology
- Sports Medicine
Background:
- Avulsion fractures of the humeral lesser tuberosity are uncommon in skeletally immature individuals.
- These injuries frequently present diagnostic challenges, leading to delayed identification and treatment.
Purpose of the Study:
- To characterize the demographics, injury mechanisms, and magnetic resonance imaging (MRI) findings of lesser tuberosity avulsion fractures in pediatric patients.
- To highlight the diagnostic utility of MRI in identifying these rare fractures.
Main Methods:
- A retrospective review of pediatric patients with MRI-confirmed lesser tuberosity avulsion fractures.
- Analysis of patient demographics, injury mechanisms, MRI characteristics, and treatment modalities.
- Radiographic evaluation, including assessment of initial interpretations and retrospective findings.
Main Results:
- Thirteen male patients (median age 13.8 years) were identified, with sports-related blunt or hyperextension injuries being the most common mechanism.
- All patients were skeletally immature; 10/13 had isolated avulsion fractures at the subscapularis footprint.
- Radiographs were often normal or misleading (e.g., concerning for tumor), with MRI proving essential for diagnosis. The axillary view was optimal for radiographic identification.
Conclusions:
- Lesser tuberosity avulsion fractures are rare, radiographically occult injuries in children, necessitating high clinical suspicion.
- MRI is effective in detecting these fractures at the subscapularis tendon footprint, with variable fragment size and displacement.
- Awareness among radiologists is vital for accurate and timely diagnosis, avoiding unnecessary procedures.
Background:
Avulsion fractures of the humeral lesser tuberosity are rare injuries in skeletally immature patients and can pose a diagnostic challenge that often leads to delayed identification.
Objective:
To describe the demographics, mechanism of injury and magnetic resonance imaging (MRI) findings of lesser tuberosity avulsion fractures in children.
Materials And Methods:
A retrospective search of children with lesser tuberosity avulsion fractures on MRI was done. Available radiographs were evaluated. Demographics, mechanism of injury, MRI characteristics and treatment were recorded.
Results:
Thirteen children, all male, were included (median age: 13.8 years, range: 12.5-16.8 years). The most common mechanism was blunt, overhead or hyperextension traumatic injury related to sports. All patients were skeletally immature and 10/13 demonstrated isolated avulsion fractures at the footprint. Only one patient had associated osteochondral injury to the humeral head and labral tear. Two children demonstrated medial dislocation/subluxation of the biceps tendon. The median size of the avulsed fragment was 15 mm (range: 5-29 mm), median anteroposterior displacement was 3 mm (range: 0-6 mm) and medial displacement was 1 mm (range: 0-20 mm). There was no correlation between age and the size of the avulsed fragment (P=0.29). Common injury patterns were complete avulsion of the subscapularis footprint (6/13) and partial avulsion of inferior footprint (6/13). Two-thirds of the radiographs were initially reported as normal, but retrospectively showed two missed fractures. One of the initial radiographs raised concern for bone tumor. The best view for identifying an avulsion fragment was the axillary view. Seven patients of the 13 patients underwent internal fixation.
Conclusion:
Avulsion fractures of the lesser tuberosity are rare, challenging to diagnose and often radiographically occult. MRI can identify the injury at the subscapularis tendon footprint with variable size and displacement. The long head of the biceps tendon is usually normal in location. Although this entity is rare, radiologists should be aware of it to allow for correct and prompt diagnosis and prevent unnecessary biopsy or contrast administration.
Related Concept Videos
01:24Magnetic Resonance Imaging
01:19Bones of the Upper Limb: Humerus