A 56-year old man who underwent posterior fixation with vertebroplasty using hydroxyapatite (HA) blocks for an L4 burst fracture developed fever and worsening low back pain 19 days after surgery. We suspected a surgical site infection, but initial imaging studies did not identify a focus. A few weeks later, the affected vertebral body collapsed and HA blocks were found scattered along the psoas major muscle, suggesting the incidence of surgical site infection. Debridement of HA blocks and anterior fixation with autologous bone grafting were performed due to instability. Intraoperative computed tomography (CT) with a navigation system was useful for detecting and removing HA blocks in the adherent psoas muscle. On day 11 after the second operation, high fever, altered consciousness, muscle rigidity, tremor, tachycardia, hypertension, diaphoresis, and an elevated creatine phosphokinase level were observed. The patient was diagnosed with neuroleptic malignant syndrome (NMS), and was treated with sodium dantrolene, bromocriptine, and diazepam.
Surgical site infection (SSI) after spinal instrumentation surgery can result in serious secondary complications, including neurological disorders, sepsis, and death. Deep incisional SSI without obvious superficial manifestations is sometimes difficult to diagnose, especially after vertebroplasty. We describe a rare case of vertebral infection after vertebroplasty using HA blocks. The infection was successfully treated using intraoperative CT with a navigation systems to remove the HA blocks.
Although NMS is rare, it is a potentially fatal condition that occurs in association with the use of neuroleptic medications. Among patients with spinal disorders, it is not uncommon to find those with psychiatric disorders or those who use causative drugs. Surgery, dehydration, poor nutritional status, and infections are possible risk factors, and spinal surgeons should consider NMS in the differential diagnosis.
View full abstract