Manubriosternal joint (MSJ) dislocation is often poorly tolerated, with pain, and both static and dynamic dysfunction in breathing. This injury is rare, and treatment includes both surgical and non-surgical interventions. Moreover, the treatment needs to be personalised to a specific case. We present a case of a 19-year-old Comorian man who had chest pains that were exacerbated by movements after falling from a tree. Careful physical examination revealed that the man had a 'stair step'-looking deformity located at the anterior chest wall at the level of the MSJ. A computed tomography scan confirmed the diagnosis of manubriosternal disruption. The patient underwent a surgical intervention under general anaesthesia and had an uneventful recovery.