Spinopelvic Instability in Conversion Total Hip Arthroplasty: A Complicated Case of Loeys-Dietz Syndrome.

A 53-year-old patient with a history of Loeys-Dietz syndrome (LDS) presented with cutout after a right femoral neck fracture treated with a dynamic hip screw. This was treated with conversion total hip arthroplasty (THA), the second reported THA in a patient with LDS and the first in a post-traumatic reconstruction setting. The patient had 2 episodes of posterior hip dislocations within 2 weeks after the operation requiring a revision THA utilizing dual-mobility bearing to achieve stability. LDS is a connective-tissue disorder that is associated with joint hypermobility and spinal deformities, among other features. These factors can affect hip pathology, approaches to treatment, and outcomes. Patients with LDS should have a comprehensive musculoskeletal evaluation and history such as those with Marfan syndrome or Ehlers-Danlos syndrome, especially if undergoing THA. Further research on the implications of LDS on the hip and spine should be performed.