Bilateral Patellar Cubiti: A Case Report

Abstract

P atell cubiti is a patella-like sesamoid bone in the triceps brachii tendon. 1 Its etiology is unknown and theories include congenital, developmental or traumatic injury. Normal radiography shows an ossicle projected posterior to the elbow joint. This case study aims to increase the awareness about the existence of patella cubiti. Case reportA 39 year-old-man with acute left elbow pain after a motor vehicle accident was admitted. At presentation, he was found to have swelling and tenderness at the distal third of the caudal aspect of the left elbow. Examination revealed tenderness with a palpable gap at the triceps brachii tendon insertion, proximal to the olecranon. The triceps brachii tendon of the left elbow joint had full function and full range of motion. AbstractPatella cubiti is a rare anomaly of the elbow, which can be unilateral or bilateral. It is a sesamoid bone in the triceps brachii tendon. The patella cubiti can be asymptomatic or symptomatic, with limitation of motion, stiffness or pain. Radiography shows a smooth well-corticated ossicle projected posterior to the elbow joint. This can be mistaken for a post-traumatic non-union of an old fracture of the olecranon tip. Radiology data and clinical examination are both important and key to an accurate diagnosis. In the case of an abnormal proximal migration of the patella cubiti, a ruptured triceps brachii tendon should be considered.

Presumed bilateral patella cubiti in a six‐month‐old German shepherd dog

“…Secondly, specific radiological signs such as smooth non-sclerotic margins and intact cortex of the bone fragments support the diagnosis of patella cubiti in human medicine. 13 In the present case, the authors highly suspected that the fragment represented a patella cubiti because the radiographic appearance of both ulnas is consistent with the description used in people. Unlike the cases described in human and veterinary literature, this dog also had radiological signs of bilateral elbow dysplasia with bilateral medial coronoid fragmentation.…”

Osseous variability around the elbow joint

“…It is still unclear whether those two bones are separate entities. According to the review by Mittal et al, there are only 18 cases described in the literature (38), but several cases could be missing (39)(40)(41)(42)(43)(44)(45)(46). Through the last century, there have been numerous articles arguing the etiology of this ossicle congenital versus traumatic (37,38,42,47).…”

Elbow Imaging: Variants and Asymptomatic Findings

“…Surgery is usually performed in symptomatic patients presenting with pain, trauma, or a fixed flexion deformity. [10][11][12] On radiographs, the patella cubiti is seen as a well-defined ossicle with a smooth contour and intact cortical surface adjacent to the olecranon process (►Fig. 1d).…”

“…Another mimic of a patella cubiti is an ununited olecranon apophysis, typically seen in preadolescent or adolescent athletes involved in overhead throwing activities such as in baseball, manifesting as a widened physis with sclerotic margins on imaging. [10][11][12] Os Supratrochleare Dorsale The os supratrochleare dorsale is an accessory ossicle located in the olecranon fossa, commonly seen in the dominant arm in males aged 15 to 40 years. 1,13 Multiple theories have been proposed about its origin, but the most popular is that it is derived from a separate ossification center in the olecranon fossa because it has a well-defined cortex and cancellous bone, gaining its nutrition from the synovial capsule.…”