Sacroiliac joint syndrome after lumbosacral fusion.

INTRODUCTION: One-third of low back pain cases are due to the sacroiliac (SI) joint. The incidence increases after lumbosacral fusion. A positive Fortin Finger Test points to the SI joint being the origin of the pain; however, clinical examination and imaging are not specific and minimally contributory. The gold standard is a test injection of local anesthetic. More than 70% reduction in pain after this injection confirms the SI joint is the cause of the pain. The aim of this study was to evaluate the decrease in pain on a Numerical Rating Scale (NRS) after intra-articular injection into the SI joint. We hypothesised that intra-articular SI injection will significantly reduce SI pain after lumbosacral fusion. METHODS: All patients with pain (NRS>7/10) suspected of being caused by SI joint syndrome 1 year after lumbosacral fusion with positive Fortin test were included. Patients with lumbar or hip pathologies or inflammatory disease of the SI joint were excluded. Each patient underwent a 2D-guided injection of local anesthetic into the SI joint. If this failed, a second 2D-guided injection was done; if this also failed, a third 3D-guided injection was done. Reduction of pain on the NRS by>70% in the first 2 days after the injection confirmed the diagnosis. Whether the injection was intra-articular or not, it was recorded. Ninety-four patients with a mean age of 57 years were included, of which 70% were women. RESULTS: Of the 94 patients, 85 had less pain (90%) after one of the three injections. The mean NRS was 8.6/10 (7-10) before the injection and 1.7/10 after the injection (0-3) (p=0.0001). Of the 146 2D-guided injections, 41% were effective and 61% were intra-articular. Of the 34 3D-guided injections, 73% were effective and 100% were intra-articular. DISCUSSION: This study found a significant decrease in SI joint-related pain after intra-articular injection into the SI joint in patients who still had pain after lumbosacral fusion. If this injection is non-contributive when CT-guided under local anesthesia, it can be repeated under general anesthesia with 3D O-arm guidance. This diagnostic strategy allowed us to confirm that pain originates in the SI joint after lumbosacral fusion in 9 of 10 patients. CONCLUSION: If the first two CT-guided SI joint injections fail, 3D surgical navigation is an alternative means of doing the injection that helps to significantly reduce SI joint-related pain after lumbosacral fusion. LEVEL OF EVIDENCE: IV, retrospective study.

Early mortality and morbidity of odontoid fractures after 70 years of age.

INTRODUCTION: Odontoid fractures are very common in older adults and are associated with a high mortality rate. The aim of this study was to evaluate the outcomes after conservative treatment of non-displaced odontoid fractures and surgical treatment of displaced fractures in patients older than 70 years. It was hypothesized that early mortality of displaced fractures is higher than in non-displaced fractures. MATERIAL AND METHODS: This was a single-center retrospective observational study of odontoid fractures (type II in the Anderson and Alonzo classification) in patients older than 70 years that occurred between 2014 and 2017. Conservative treatment with immobilization for 3 months was proposed when the fracture was displaced less than 2 mm (non-displaced fracture group). Surgical treatment in the form of anterior screw fixation was proposed when the fracture displacement was more than 2 mm (displaced fracture group). The primary endpoint was the mortality rate at 3 months. RESULTS: The study included 79 patients (46 women) who had a mean age of 85 years (70-105). The 3-month mortality in the entire cohort was 27% and the 1-year mortality was 30%. Conservative treatment was provided to the 36 patients with non-displaced fractures. The 3-month mortality rate in this group was 11%. A displaced fracture occurred in 43 patients: 17 were treated surgically by anterior screw fixation; 20 could not be operated on because of anesthesia contraindications and 6 died within 24hours of the fracture event. The 3-month mortality rate in this group was 40%; 3 of the 17 operated patients died from postoperative respiratory complications; 8 of the 20 patients with contraindications died, in addition to the 6 that died soon after the fracture occurred. DISCUSSION: This study confirms that mortality and morbidity are high following odontoid fractures. The mortality rate was significantly higher in patients with displaced fractures, confirming our hypothesis. The mortality rate was especially high when patients with displaced fractures could not undergo surgery because of anesthesia contraindications. Also, there was a high rate of respiratory complications after anterior screw fixation of displaced fractures. CONCLUSION: Given our findings, conservative treatment should be compared to surgical treatment for displaced fractures and the anterior approach should be compared to the posterior one for surgical cases. LEVEL OF EVIDENCE: IV.