Posterior hinge fixation for the treatment of unstable traumatic sacroiliac joint injuries.

INTRODUCTION: Posterior hinge fixation (PHF) is a sacroiliac joint fixation method indicated for the surgical treatment of unstable pelvic ring fractures (tile C). HYPOTHESIS: PHF yields good functional outcomes based on the Majeed score at more than 1 year of follow-up. METHODS: A single-center, retrospective study of patients who had a Tile C pelvic ring fracture, who were operated by PHF and who were evaluated at a minimum follow-up of 1 year. The functional outcome was determined using the Majeed score and pain was evaluated by the patients using a visual analog scale (VAS). The preoperative, intraoperative and postoperative data, complications and sequelae were documented. A CT-scan was done at least 1 year after the surgical treatment to determine the SI joint's reduction and fusion. RESULTS: Included were 22 patients (59% men) who had a mean age of 37.3±11.9 years; 21 of these patients were reviewed at a mean of 4.8±4 years. The mean Majeed score at the final assessment was 76.4 points±15.3, with 24% of patients having excellent results (n=5), 53% having good results (n=11), 19% having average results (n=4) and 5% having poor results (n=1). The mean pain level on VAS was 28±23mm. Of the eight surgical site infections, seven occurred in the PHF (88%). CT-scans taken at 1 year postoperative were compared to the preoperative scans. The pelvic opening was reduced by -9±6 (p<0.01), SI diastasis by -11mm±9 (p<0.001), vertical displacement by-7mm±8 (p<0.001), symphysis opening by -15mm±15 (p<0.001), median transverse diameter by -10mm±9 (p<0.001) and bispinal diameter by -5mm±7 (p<0.001). SI fusion was confirmed in 43% of patients (n=9). CONCLUSION: PHF is a surgical instrumentation method that provides satisfactory long-term reduction of Tile C pelvic ring fractures. The clinical outcomes are good or excellent in 77% of cases. The perioperative morbidity is marked by surgical site infections, all of which healed. LEVEL OF EVIDENCE: IV; retrospective, non-comparative cohort study.

Impact of assessment of bone status before corrective surgery of lumbar spine in patients over 50 years old.

Background and objective: There is absence of data on the prevalence of osteoporosis before corrective surgery of the lumbar spine. We do not know the impact of bone assessment before corrective spine surgery, regarding the prevalence of osteoporosis, risk factors for osteoporosis, and prescription of osteoporotic treatment. Our objective was to evaluate the impact of assessment of bone status before corrective surgery of the lumbar spine. Methods: This retrospective study was conducted over a period of 30 months. Patients included were over 50 years old and had been referred to rheumatology consultation prior to corrective surgery of the lumbar spine with osteosynthesis, for scoliosis or spondylolisthesis. Assessment of bone status consisted in looking for risk factors for osteoporotic fracture, performing bone densitometry with the calculation of TBS (trabecular bone score) and the possible introduction of treatment for osteoporosis. Data were collected on complications related to bone fragility during follow-up. Results: Twenty-eight patients with a median age of 71.2 years (55.5-84.8) were included; 89% were women. T score was <-2.5 in 14.3% (4/28) and -1 to -2.5 in 42.9% (12/28) on at least one of the three sites analyzed. Fifty percent of patients had a TBS <1.2, a history of more than four falls per year, a duration of more than 20 s in the Timed Up and Go Test, and/or sedation treatment. Vitamin-calcium supplementation and treatment for osteoporosis were prescribed in 71.4% and 17.8% of cases, respectively. During follow-up, 3 patients had one or more osteoporotic vertebral fractures and 4 patients had loosening of implanted devices. Conclusion: Despite a low prevalence of densitometric osteoporosis and therapeutic management, one in four patients had a bone complication, suggesting the superiority of TBS as an indicator of bone status.

CT analysis of C2 pedicles morphology and considerations of useful parameters for screwing.

INTRODUCTION: Surgery of cervical spine steadily requires realizing posterior osteosynthesis. The anchoring of instrumentation in C2 steadily constitutes an important stake of prognosis. Pedicle screwing is one of the best options and remains associated with a low morbidity. The aim of this CT study is to provide, from a wide population, the descriptive anatomical parameters of C2 pedicles. The data enable this analysis of feasibility of C2 pedicles screwing. MATERIALS AND METHODS: A continuous and retrospective series have explored 100 CT scans of the cervical spine without finding C2 fracture. The software OSIRIX v5.0.2 has been used. The dimensions of the pedicles in C2 as length, diameter, and distance from the vertebral foramens have been measured from the preset posterior entry point. Their orientation has been described in the axial and sagittal plan by the pedicle transverse angle, the sagittal angle and the pedicle-lamina angle used as a visible mark during the procedure. At least, the feasibility of pedicle screwing has been evaluated using a diameter criterion higher than 4 mm. RESULTS: The dimensions analysis of 200 studied pedicles has found an average length as 26.18 mm, an average diameter as 5.18 mm and an average distance between the entry point and the vertebral foramen as 9.06 mm. Their orientations have an average PTA as 36.6° and a SA as 25.8°. The average of the PLA was 81.3. The screwing feasibility has been evaluated as 92.5 % in the whole series. CONCLUSION: These morphological data come from a large series give some help for the C2 pedicle screwing preoperative planning. These lean on 3D measures but also on accessible mark during the procedure and despite the difference of the patient orientation. A CT preoperative planning of the pedicle screwing remains essential because more than 7 % of the pedicles have a diameter lower than 4 mm.