52-year-old male patient who fell onto the outstretched arm, presented inflammation, pain and limited articular range, associated with a palpable defect in the posterior region of the elbow.
Lateral radiograph of the elbow shows a spur at the dorsum of the olecranon process with a small bony avulsion (‘flake sign’) located posterior to the distal humerus.
MRI showed proximal retraction and isolated rupture of the superficial triceps tendon (lateral and long heads), with an intact deep tendon (medial head).
Clinical Perspective: Sierra et al mentioned that rupture of the triceps tendon is a rare situation, with only 50 cases reported from 1987 to 2006 [1]. However, Koplas et al in his study referred that the prevalence of triceps tendon injuries was 3.8% (18 patients with partial tears and 10 with complete tears) [2]. Predisposing factors for triceps tendon tear include olecranon bursitis (local steroid injection), hyperparathyroidism and renal failure, weight-lifting (anabolic steroid use), and systemic corticosteroid use [2].
Imaging Perspective: The occurrence of partial-thickness triceps brachii tears selectively involving the superficial layer of the triceps may be explained by the unique anatomy of the distal tendon insertion on the olecranon [3].
The triceps brachii muscle is part of the posterior group of the elbow muscles and is formed by three heads (long, lateral, and medial), hence, its name [4].
The lateral and long heads converge distally to form a fused flattened tendon that inserts into the posterior part of the proximal end of the olecranon (Fig. 3). The medial head originates from the medial aspect of the radial groove of the humerus. The long and lateral heads give rise to a single tendon that inserts onto the olecranon. The superficial fibres continue as the triceps expansion and insert into the posterior crest of the ulna medially and the fascia of the extensor carpi ulnaris laterally (Fig. 3). The medial head remains muscular more distally until close to the insertion where it gives rise to a separate tendon that inserts in part to the olecranon, in part to the flattened fused tendon of the long and lateral heads, and in part to the posterior aspect of the elbow joint capsule (Fig. 3), preventing impingement of the capsule on extension of the elbow [5]. The tendon may have a bipartite appearance on MRI but histological studies have shown that the tendon fuses to form one unit before insertion on to the olecranon [6] (Fig. 3).
Presence of spur at the dorsum of the olecranon process and ectopic calcifications into the tendon can be related to enthesopathy and chronic tendinitis and may alter structural tendon integrity [7].
Outcome: Surgical repair of partial ruptures, however, remains controversial, because good results of conservative treatment are often sufficient and effective in these cases. However, the authors recommend surgical repair in strength workers or sportsmen and in young people [6].
Isolated tear of the superficial triceps tendon.
In the coronal and sagittal MRI sequences, the triceps tendon (mainly the superficial portion formed by the lateral head and long head after merging) near its insertion shows abnormal signals, accompanied by local soft tissue swelling. A small amount of high signal within the soft tissue spaces suggests a partial tear or rupture of the tendon fibers. In some images, bony outgrowths (“beak-like” or “spike-like” in appearance) are observed in the posterior elbow, consistent with common osteophytes at the olecranon. The X-ray plain film shows mild hyperplasia or calcification of the olecranon shape, with no obvious signs of an acute fracture.
There is visible swelling of the subcutaneous tissue, and no clear independent cystic lesion is found on the MR images; however, chronic inflammation or bursitis cannot be ruled out. No significant evidence of a major muscular tear or complete rupture is observed, but clinical examination is still required to confirm these findings.
Combining the patient’s age (52 years), injury mechanism (fall), clinical symptoms (posterior elbow pain, restricted joint movement, a palpable defect), and MRI findings of high signal changes in the superficial fibers of the triceps tendon, the most likely diagnosis is:
“Partial tear of the triceps tendon, with potential bony outgrowth and chronic enthesopathy at the insertion.”
If uncertainty remains, further evaluation using ultrasound or surgical exploration could clarify the extent of the tendon tear. If there is any doubt about the integrity of the tendon attachment, a dynamic ultrasound or repeat MRI evaluation could be considered.
Depending on the extent of the partial tear in the triceps tendon, the patient’s functional needs, and daily activities, the following strategies may be considered:
Rehabilitation/Exercise Prescription Suggestions:
Throughout the rehabilitation process, strictly follow the FITT-VP principle (Frequency, Intensity, Time, Type, Volume, Progression), and adjust dynamically based on the patient’s recovery. If the patient has osteoporosis or other underlying conditions, ensure the training intensity and exercise modalities are safe and feasible to avoid re-injury.
This report is a reference analysis based on existing imaging findings and clinical information. It does not replace in-person consultation or professional medical advice. If you have further questions or if your condition changes, please seek medical attention promptly.
Isolated tear of the superficial triceps tendon.
