Figure A is the lateral radiograph of a 44-year-old male who sustained a fall on his outstretched hand while rollerblading. The patient reports pain localized to the posterior elbow and refuses to attempt elbow extension secondary to pain and swelling. Which of the following is the most likely diagnosis in this patient?
Exacerbation of elbow arthritis
Olecranon bursitis
Lateral collateral ligament tear
Triceps rupture
Triceps rupture
The flake sign, as seen in Figure A is pathognomonic of a triceps tendon rupture.

Tricep tendon ruptures are rare injuries to the elbow extensor mechanism that most commonly occur as a result of forceful elbow contraction. Diagnosis can be made clinically, as patients with complete ruptures are unable to extend the elbow against gravity. An MRI may be useful in the diagnosis in patients whom are too painful to examine or who may have partial tears of the triceps tendon. Surgical repair is indicated in patients with complete rupture or in those with >50% tears and significant weakness.

Yeh et al. review distal triceps ruptures. They report that these injuries are commonly caused by a fall on an outstretched hand or a direct blow. If identifiable on plain radiograph a flake sign or avulsion of the olecranon tip will be appreciated. They conclude that diagnosis may be difficult initially in a painful elbow, however, a combination of plain radiographs and MRI can assist in making the correct diagnosis.

Beazley et al. review distal biceps and triceps injuries. They report that these injuries most commonly occur in middle-aged males as a result of eccentric loading of the tendon. They conclude that patients who undergo early diagnosis and surgical treatment can expect to have excellent outcomes.

Keener et al. review distal tricep tendon injuries. They report that most complete tears are treated surgically in medically fit patients. Partial-thickness tears are managed according to the tear severity, functional demands, and response to conservative treatment. They conclude that anatomic footprint repair of the triceps with optimal tendon to bone healing results in an acceptable functional outcome.

Figure A is the lateral radiograph of an elbow demonstrating a flake sign from the olecranon tip indicative of a triceps rupture.

Incorrect Answers:
Answer A: The patient does not show significant elbow degenerative disease on plain radiographs.
Answer C: Olecranon bursitis is not likely to worsen acutely after a fall, nor are there any other indications of this diagnosis in the present patient.
Answer D: While lateral collateral ligament tears may occur following a fall on an outstretched arm, there is no indication that an elbow dislocation occurred here and based on current radiographs a triceps rupture is more likely.
Answer E: Anconeus avulsions fractures are identified as lateral epicondyle fractures.