Use of a newly developed minimally invasive bilateral fixed angle locking system in the treatment of pathological pelvic fractures: a case series.

Background: Metastatic bone disease (MBD) and its complications have a significant impact on patients' quality of life. Pathological fractures are a particular problem as they affect patient mobility and pose a high risk of non-union. The pelvis is frequently affected by MBD and its fixation is challenging. We present a case series of three pathological sacral fractures treated with a new minimally invasive bilateral fixed angle locking system.

Case presentation: Case 1 and 2 suffered a pathological transforaminal sacral fracture without adequate trauma in stage 4 carcinomas (gastric cancer and breast cancer). Both were initially treated with non-surgical treatment, which had only a limited effect and led to imminent immobility. Both were operated on with fluoroscopic navigation and underwent transsacral SACRONAIL^® stabilisation according to CT morphology (S1 + S2 and S1 respectively). Immediately after the operation, pain decreased and mobilisation improved. Case 3 had a pathological transalar sacral fracture during the 2nd cycle of chemotherapy due to non-Hodgkin's lymphoma. He soon became immobile and could only move in a wheelchair. The operation was performed with CT navigation due to the very small corridors and an implant was inserted in S1 and S2. The patient reported immediate pain relief and his ability to walk improved over the following months. Despite continued chemotherapy, no wound complications occurred.

Conclusions: The cases show the advantages of the minimally invasive bilateral fixed angle locking system SACRONAIL^® in the treatment of patients with pathological sacral fractures. It allows immediate full weight bearing and the risk of secondary surgical complications is low. All cases showed an improvement in pain scores and mobility.