Retroperitoneal arterial bleeding caused by an undisplaced conservatively treated hyperextension injury of the lumbar spine – A case report

Background: Hyperextension fractures of the thoracolumbar spine are commonly seen in ankylotic disorders due to the rigidity of the spine. The known complications include instability, neurological deficits and posttraumatic deformity but there is no report of a hemodynamic relevant arterial bleeding in undisplaced hyperextension fractures. An arterial bleeding poses a life-threatening complication and may be difficult to recognize in an ambulatory or clinical setting. Case presentation: A 78-year-old male was brought to the emergency department after suffering a domestic fall with incapacitating lower back pain. X-rays and a CT scan revealed an undisplaced L2 hyperextension fracture which was treated conservatively. 9 days after admission, the patient complained about unprecedented abdominal pain with a CT scan disclosing a 12 × 9 × 20 cm retroperitoneal hematoma on grounds of an active arterial bleeding from a branch of the L2 lumbar artery. Subsequently, access via lumbotomy, evacuation of the hematoma and insertion of a hemostatic agent was performed. The therapy concept of the L2 fracture remained conservatively. Conclusions: A secondary, retroperitoneal arterial bleeding after a conservatively treated undisplaced hyperextension fracture of the lumbar spine is a rare and severe complication that has not been described in literature yet and may be difficult to recognize. An early CT scan is recommended in case of a sudden onset of abdominal pain in these fractures to fasten treatment and hence decrease morbidity and mortality. Thus, this case report contributes to the awareness of this complication in a spine fracture type with increasing incidence and clinical relevance

Cement-augmented screw fixation for calcaneal fracture treatment: a biomechanical study comparing two injectable bone substitutes

Background The role of cement-augmented screw fixation for calcaneal fracture treatment remains unclear. Therefore, this study was performed to biomechanically analyze screw osteosynthesis by reinforcement with either a calcium phosphate (CP)-based or polymethylmethacrylate (PMMA)-based injectable bone cement. Methods A calcaneal fracture (Sanders type IIA) including a central cancellous bone defect was generated in 27 synthetic bones, and the specimens were assigned to 3 groups. The first group was fixed with four screws (3.5 mm and 6.5 mm), the second group with screws and CP-based cement (Graftys (R) QuickSet; Graftys, Aix-en-Provence, France), and the third group with screws and PMMA-based cement (Traumacem (TM) V+; DePuy Synthes, Warsaw, IN, USA). Biomechanical testing was conducted to analyze peak-to-peak displacement, total displacement, and stiffness in following a standardized protocol. Results The peak-to-peak displacement under a 200-N load was not significantly different among the groups; however, peak-to-peak displacement under a 600- and 1000-N load as well as total displacement exhibited better stability in PMMA-augmented screw osteosynthesis compared to screw fixation without augmentation. The stiffness of the construct was increased by both CP- and PMMA-based cements. Conclusion Addition of an injectable bone cement to screw osteosynthesis is able to increase fixation strength in a biomechanical calcaneal fracture model with synthetic bones. In such cases, PMMA-based cements are more effective than CP-based cements because of their inherently higher compressive strength. However, whether this high strength is required in the clinical setting for early weight-bearing remains controversial, and the non-degradable properties of PMMA might cause difficulties during subsequent interventions in younger patients