Distal Triceps Tendon Tears: Magnetic Resonance Imaging Patterns Using a Systematic Classification

Objective This study aimed to evaluate distal triceps tendon tear patterns using a systematic classification based on the tendon's layered structure. Methods We retrospectively identified Magnetic resonance imaging (MRI) examinations with triceps tendon tears that underwent reconstructive surgery. Magnetic resonance images were reviewed independently by 2 musculoskeletal radiologists to determine tendon layer involvement and ancillary findings, including tear size, involvement of triceps lateral expansion, and presence of olecranon bursal fluid. Surgical reports were scrutinized for level of anatomic detail and correlation with imaging findings. Results We identified 69 triceps tendon tears in 68 subjects (61 men, 7 women; mean age, 45 ± 12 years) who underwent surgical reconstruction. On MRI, the superficial layer was always involved with either a partial or full-thickness tear. The most common tear pattern was a combination of superficial layer full-thickness tear with deep layer partial tear (25 of 69 [36%]). Mean tear length was 24 ± 12 mm. We found no cases of isolated deep layer tears. Involvement of triceps lateral expansion and presence of bursal fluid correlated positively with tear severity of superficial and deep layers (P < 0.001). Detailed surgical correlation was limited, with only 9 of 69 (13%) of surgical reports containing information specifically addressing individual tendon layers. Conclusions Triceps tendon tears show tear patterns following its layered structure and can be assessed by MRI. Radiologists and surgeons are encouraged to describe tear patterns considering both superficial and deep tendon layers.