Dysbaric osteonecrosis of the humeral head in a patient with type 2 decompressive sickness.

INTRODUCTION: Dysbaric osteonecrosis, albeit rare, have been reported in patients with decompression sickness. We report a patient with dysbaric osteonecrosis, diagnosed 60 days after presenting with decompression sickness.

CASE PRESENTATION: A 38-year-old, previously fit and healthy male, noted his tank running out of air at approximately 40-50 m while diving, surfaced rapidly before losing consciousness. Upon gaining consciousness, he noted loss of power on all four limbs. He completed 26 sessions of hyperbaric oxygen treatment. Magnetic resonance (MR) of the spine noted T2 abnormality in the upper cervical spine, with some involvement of the central grey matter and the remainder of the cord. According to the International Standards for Neurological Classification of Spinal Cord Injury, it was noted clinically that the patient had a T9 neurological level with ASIA impairment scale A. MR imaging (MRI) of the shoulder was performed, 60 days since initial presentation, after the patient complained of shoulder pain, noted non-specific subcortical oedema of the humeral head, which suggested early osteonecrosis.

DISCUSSION: Dysbaric osteonecrosis is rare but remains extremely important to be recognised as a potential complication from decompressive sickness. The increased risk of pathological fractures with dysbaric osteonecrosis plays an important role as it may alter the rehabilitation prescription. One of the unique features of this case, apart from its rarity, was that it was diagnosed 60 days from his initial presentation, when he has passed his acute phase of illness.