Surgical Treatment of Spinal Fracture in a Patient With Ankylosing Spondylitis: An Opportunity To Correct Spinal Deformity Simultaneously With Fracture Fixation?

Iatrogenic vertebral fracture in ankylosed spine during liver transplantation: a case report and biomechanical study using finite element method

PURPOSE

The occurrence of an iatrogenic vertebral fracture during non-spinal digestive surgery is an exceptional event that has not been previously documented. Our study aims to explain the occurrence of this fracture from a biomechanical perspective, given its rarity. Using a finite element model of the spine, we will evaluate the strength required to induce a vertebral fracture through a hyperextension mechanism, considering the structure of the patient's spine, whether it is ossified or healthy.

METHODS

A 70-year-old patient was diagnosed T12 fracture during a liver transplantation on ankylosed spine. We use a finite element model of the spine. Different mechanical properties were applied to the spine model: first to a healthy spine, the second to a osteoporotic ossified spine. The displacement and force imposed at the Sacrum, the time and location of fractures initiation were recorded and compared between the two spine conditions.

RESULTS

A surgical treatment is done associating decompression with posterior fixation. After biomechanical study, we found that the fracture initiation occurred for the ossified spine after a sacrum displacement of 29 mm corresponding to an applied force of 65 N. For the healthy spine it occurred at a sacrum displacement of 52 mm corresponding to an applied force of 350 N.

CONCLUSION

The force required to produce a type B fracture in an ankylosed spine is 5 times less than in a healthy spine. These data enable us to propose several points of management to avoid unexpected complications with ankylosed spines during surgical procedures.

LEVEL OF EVIDENCE

IV.

Surgical treatment of thoracolumbar fracture in ankylosing spondylitis: A comparison of percutaneous and open techniques

BACKGROUND CONTEXT

Posterior percutaneous long-segment internal fixation and open fixation with long-segment screws have been used to treat thoracolumbar fractures in ankylosing spondylitis patients.

PURPOSE

To observe the clinical effect of posterior percutaneous long-segment internal fixation in 26 ankylosing spondylitis (AS) patients with thoracolumbar fractures.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

Forty-seven AS patients who were diagnosed with thoracolumbar fractures and treated from December 2014 to December 2018.

OUTCOME MEASURES

Visual analog scale score, Cobb angle, American Spinal Injury Association Grade, SF-Qualiveen score, pedicle screw misplacement rate, operative duration, blood loss, complications, bed rest duration and modified MacNab score.

METHODS

All patients were divided into the percutaneous group (PG) and the open group. Twenty-six patients were treated with percutaneous long-segment internal fixation, and the remaining 21 underwent open fixation with long-segment screws. The minimum follow-up period was 12 months.

RESULTS

The operations were successful in both groups. A patient in the PG showed class C wound healing, while the others showed class A healing, and some patients experienced perioperative complications. All patients were followed up for 12-48 months (mean, 33.81 months), and all patients showed clinical osseous fracture healing. Significant differences were found in operative duration, intraoperative blood loss and postoperative bed rest duration between the two groups (P < 0.05). No significant difference was found in improvement of the visual analog scale score, Cobb angle of spinal kyphosis or neurological function after the operation (P > 0.05).

CONCLUSIONS

As a minimally invasive procedure, posterior percutaneous long-segment internal fixation requires less time, results in less blood loss and causes less trauma. This procedure can also improve patients' pain, neurological function and kyphotic deformity and achieve effects similar to those of traditional methods. With this curative clinical effect, this procedure can be used as an ideal surgical treatment for thoracolumbar fractures in AS patients, especially for elderly patients with underlying diseases and high surgical risk.