Comparative outcome of different treatment options for fragility fractures of the sacrum
Authors: Andresen Julian Ramin , Radmer Sebastian , Andresen Reimer , Prokop Axel , Schröder Guido , Nissen Urs , Schober Hans-Christof 
Published: December 2022

Abstract
Background
Fragility fractures of the sacrum (FFS) have been detected more and more frequently in recent times, and the incidence will continue to increase due to increasing life expectancy. The aim of this study was to compare the clinical outcome of conservative, interventional and surgical treatment of FFS.

Methods
Retrospectively, 292 patients (276 women, 16 men) with confirmed FFS were followed up over a period of 2 years. The age of the women was Ø 81.2 (58 - 99) and that of the men Ø 78.1 (76 - 85) years. The pain was quantified using a VAS. Fractures were classified in accordance with the Rommens and Hofmann and with the Denis classification using conventional X-rays, CT and MRI. A QCT of the lumbar spine was performed to quantify bone mineral density. Concomitant diseases of every patient were recorded. An interdisciplinary case conference determined the individual treatment concept considering the age, type of fracture, pain level and comorbidities with classification into conservative, interventional (any type of sacroplasty) or surgical treatment. Over the course pain and independence were measured, complications and patient satisfaction were documented. A vitamin D determination was done, and existing comorbidities were included.

Results
Patients with a pain level of ≤5 benefited from the conservative therapy measures, with pain levels > 5 significantly delaying the development of mobility. After sacroplasty, the pain reduced significantly, which caused a rapid improvement in mobility without any significant difference being found between vertebro- (VSP), balloon (BSP), radiofrequency (RFS) and cement sacroplasty (CSP). In terms of pain reduction and mobilization, the surgical treated patients benefited from osteosynthesis, although more complex fracture types with lumbopelvic stabilization took longer. Overall, there were no deaths during the hospital stay. Mortality after 12 months was 21.7% for the conservative, 8.4% for the interventional and 13.6% for the surgical therapy group; the differences are significant. For patients in the conservative therapy group who were difficult to mobilize due to pain, the mortality increased to 24.3%. Over 24 months, patients achieved the best independence after sacroplasty. At 12 and 24 months, subjective satisfaction with the therapies was best after sacroplasty, followed by osteosynthesis and conservative measures. All patients had a pronounced vitamin D deficiency and manifest osteoporosis. Cardiovascular pathologies were the main concomitant diseases.

Conclusions
Patients with FFS with a low level of pain benefit from conservative therapy measures, whereby complications and mortality increase significantly in the case of persistent immobilizing pain. Patients with an unacceptable level of pain resulting from non-dislocated fractures benefit significantly from sacroplasty. Patients with unstable and displaced fractures (Rommens and Hofmann type III and IV) should be operated on promptly. Different techniques are available for sacroplasty and osteosynthesis, which lead to an improvement of independence and a reduction in mortality.