Case report: Low trauma posterior native hip dislocation in
A 60-year-old gentleman was admitted with weakness of both legs. He had presented 2 days prior complaining only of lower abdominal pain. In the following 2 days he complained of an increasingly unsteady gait with tingling in both his hands and feet. This culminated in a simple fall while trying to get out of bed on the morning before the day of admission. He was unable to mobilise after this point.

Examination revealed an internally rotated and shortened left leg however, he was able to perform straight leg raise to some extent. Hypotonia was noted in both lower limbs. Bilateral distal upper limb weakness graded 4/5 and lower limb weakness graded 3/5 proximally and 2/5 distally. He had sensory deficit level of T12 on the Right and L2 on the Left, reduced vibration sensation up to the knee and abolished lower limb reflexes. His cranial nerve examination was normal and other systemic examinations were unremarkable.

Radiographs of the left hip revealed a posteriorly dislocated native hip with no obvious associated bony injury. T2 weighted MRI with gadolinium contrast of the whole spine revealed extensive spinal cord signal abnormality predominantly involving the cervical and lower thoracic regions including the conus suggestive of longitudinal acute transverse myelitis. CT of the chest revealed Left lower lobe consolidation with peripheral areas of ground glass change in the Right lung. Nasopharyngeal swab for SARS-CoV-2 was positive with initial blood tests showing a raised C-Reactive Protein (CRP).

Patient was taken to theatre to successfully reduce his hip and was commenced on intravenous methylprednisolone for which he received a total of 4.5 g followed by high dose prednisolone. His folate and vitamin B12 were also replaced and was kept on bed rest for 2 weeks prior to being mobilised by the physiotherapists. 3 weeks after admission, a new leg length discrepancy was noted, and x-rays confirmed a re-dislocation of the Left hip. The patient did not complain of any pain which is most likely due to sensory loss caused by transverse myelitis. This was again successfully reduced in theatre.

The patient was kept on bed rest with a de-rotation boot. Daily leg length measurement was caried out with comparison to the normal side. Repeat T2 Weighted MRI 6-weeks after admission reported complete resolution of previously seen cord signal change. The patient's sharp and soft touch sensory loss and motor weakness had completely resolved.