Surgical treatment of post-traumatic vertebral osteonecrosis including intravertebral expansive implants-clinical, functional and imaging outcomes and a center experience over 7 years.

Background: The effective treatment of post-traumatic vertebral osteonecrosis continues to be an under discussion and controversial subject. Armed kyphoplasty with expansive intravertebral implants is an emerging procedure, which, in theory, allow for a more effective preservation of the restored vertebral height. The development of the indications for these recent devices has given rise to auspicious outcomes in vertebral non-union situations. The aim of this study is to evaluate the clinical, functional and imaging outcomes of the surgical treatment of situations of post-traumatic vertebral necrosis, following a therapeutic algorithm that includes armed kyphoplasty with intravertebral expansive implants and bridge pedicular stabilization, according to a predefined necrosis stage.

Methods: We present a retrospective observational study, in which 35 patients took part, including a total of 35 cases of post-traumatic vertebral osteonecrosis submitted to surgical treatment over 7 years (between 2016 and 2023) at the same center according to a defined therapeutic algorithm. The cases were staged according to vertebral morphology (non-plana or plana) and mobility (mobile or immobile)-stages 1m (mobile necrotic vertebra non-plana), 1i (immobile necrotic vertebra non-plana), 2m (mobile necrotic vertebra plana), and 2i (immobile necrotic vertebra plana)-and the following surgeries were performed: armed kyphoplasty with intravertebral expansive implants filled with bone cement, associated or not to adjacent pedicle instrumentation; or bridge pedicle fixation of the adjacent levels. Clinical results [Patient Global Impression of Change (PGIC), Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI)] as well as imaging outcomes (restoration and preservation of the heights of the vertebral body) were studied. The mean follow-up time corresponded to 3.17 years (range, 1-7.5 years).

Results: Most of the clinical-functional and imaging parameters showed important improvements after surgical treatment, with few complications. A statistically significant greater degree of functional improvement was found in plana vertebrae when compared to non-plana, which reflects that the first are quite symptomatic and disabling at the beginning and improve a lot with surgical treatment. Significant indirect correlations were found between the time from the initial fracture to surgical intervention after diagnosis of vertebral necrosis and the anterior sagittal height in the immediate postoperative time and at the ending of the follow-up. Also, a significant direct correlation was identified between this time and the VAS for pain at the end of the follow-up and the PGIC scale in the same period. It was also found that patients with surgical complications had a statistically significantly longer time between the initial fracture and surgery for post-traumatic necrosis.

Conclusions: We present the results of a surgical therapeutic algorithm that includes the use of recent expansive intravertebral implants at post-traumatic vertebral osteonecrosis, resulting in satisfactory clinical, functional and imaging results. This work shows a pioneering statistical demonstration of the clinical, functional and imaging importance of early detection of this condition (ideally in vertebrae non-plana morphology stages), so that there is still sufficient bone tissue in the vertebral body to permit the stabilization and restoration of its anatomy through a minimally invasive interior reconstruction, with percutaneous access and quicker convalescence, that is to say, armed kyphoplasty, avoiding the unwanted disease progression that will require more aggressive surgical solutions that doesn't allow anatomical restauration.