Dorsal instrumentation with and without vertebral body replacement in patients with thoracolumbar osteoporotic fractures shows comparable outcome measures

Purpose In the surgical treatment of osteoporotic spine fractures, there is no clear recommendation, which treatment is best for the individual patient with vertebra plana and/or neurological deficit requiring instrumentation. The aim of this study was to evaluate clinical and radiological outcomes after dorsal or 360° instrumentation of osteoporotic fractures of the thoracolumbar spine in a cohort of patients representing clinical reality. Methods A total of 116 consecutive patients were operated on between 2008 and 2020. Inclusion criteria were osteoporotic fracture, thoracolumbar location, and dorsal instrumentation. In 79 cases, vertebral body replacement (VBR) was performed additionally. Patient outcomes including complications, EQ-5D at follow-up, and sagittal correction were analyzed. Results Medical and surgical complications occurred in 59.5% of patients with 360° instrumentation compared to 64.9% of patients with dorsal instrumentation only (p = 0.684). Dorsal instrumentation plus VBR resulted in a sagittal correction of 9.3 ± 7.4° (0.1–31.6°) compared to 6.0 ± 5.6° (0.2–22.8°) after dorsal instrumentation only, respectively (p = 0.0065). EQ-5D was completed by 79 patients after 4.00 ± 2.88 years (0.1–11.8 years) and was 0.56 ± 0.32 (− 0.21–1.00) for VBR compared to 0.56 ± 0.34 (− 0.08–1.00) without VBR after dorsal instrumentation (p = 0.994). Conclusion 360° instrumentation represents a legitimate surgical technique with no additional morbidity even for the elderly and multimorbid osteoporotic population. Particularly, if sufficient long-term construct stability is in doubt or ventral stenosis is present, there is no need to abstain from additional ventral reinforcement and decompression.

Does the Current State of Evidence Justify the Broad Use of Cross-Links in Dorsal Instrumentation? A Systematic Review

Cross-links increase the stability of screw-rod systems in biomechanical testing. The aim of this systemic review was to find evidence pertaining to the additional benefit of the implantation of cross-links in clinical practice in regard to different spinal diseases. Therefore, a systematic literature analysis of two online databases was performed according to the PRISMA statement. Inclusion criteria were prospective and retrospective studies investigating the use of cross-links in dorsal instrumentation. Biomechanical studies and case series were excluded. A total of seven retrospective studies remained for final full-text evaluation. In total, two studies each address the use of cross-links in adolescent idiopathic scoliosis, neuromuscular scoliosis or atlantoaxial fusion, one study in congenital scoliosis. In atlantoaxial fusion the additional use of cross-links may provide earlier bony fusion. In surgical treatment for pediatric scoliosis the additional use of cross-links does not provide additional benefit. Radiological outcome and complication rate did not differ in between groups. No study addressed the use of cross-links in short- or long-segment fusion due to degenerative or traumatic disorders of the spine. There is a deficiency in published literature towards the impact of cross-links in spinal surgery. The current clinical evidence data do not confirm the biomechanical advantages of cross-links in clinical practice. Further studies are needed to warrant the use of cross-links in the future.

Accuracy of Intraoperative Computed Tomography Assisted Dorsal Instrumentation in Spinal Revision Surgery

Purpose Instrumentation in spinal revision surgery is considered challenging. Altered or missing anatomical landmarks hinder the surgeons' intraoperative orientation. In recent history, the importance of navigated approaches to spinal screw placement is constantly increasing. A growing number of medical centers have introduced intraoperative CT (iCT) navigation as a new clinical standard. In this study, we compare the accuracy of dorsal iCT-navigated instrumentation in revision surgery versus primary interventions. Methods Between September 2017 and January 2019, we prospectively analyzed a consecutive series of dorsal instrumentation using iCT. Patients with previous operative interventions in the relevant spinal segments were included in the revision group and compared with a previously assessed group of primary interventions (nonrevision group). Each screw was assessed individually by an independent observer, making use of a modified Gertzbein and Robbins classification. Results In this period, 39 patients were treated in the revision group with a total amount of 269 implanted screws. We achieved an overall accuracy of 95.91% compared with 95.12% in the nonrevision group (46 patients, 287 screws). We found no significant difference in accuracy between the two groups or any anatomical region of the spine. Conclusion In summary, iCT-navigated screw placement yields a good accuracy in spinal revision surgery, without significant difference to primary interventions.

Percutaneous Dorsal Instrumentation of Vertebral Burst Fractures: Value of Additional Percutaneous Intravertebral Reposition—Cadaver Study

Purpose. The treatment of vertebral burst fractures is still controversial. The aim of the study is to evaluate the purpose of additional percutaneous intravertebral reduction when combined with dorsal instrumentation.Methods. In this biomechanical cadaver study twenty-eight spine segments (T11-L3) were used (male donors, mean age 64.9 ± 6.5 years). Burst fractures of L1 were generated using a standardised protocol. After fracture all spines were allocated to four similar groups and randomised according to surgical techniques (posterior instrumentation; posterior instrumentation + intravertebral reduction device + cement augmentation; posterior instrumentation + intravertebral reduction device without cement; and intravertebral reduction device + cement augmentation). After treatment, 100000 cycles (100–600 N, 3 Hz) were applied using a servohydraulic loading frame.Results. Overall anatomical restoration was better in all groups where the intravertebral reduction device was used (p<0.05). In particular, it was possible to restore central endplates (p>0.05). All techniques decreased narrowing of the spinal canal. After loading, clearance could be maintained in all groups fitted with the intravertebral reduction device. Narrowing increased in the group treated with dorsal instrumentation.Conclusions. For height and anatomical restoration, the combination of an intravertebral reduction device with dorsal instrumentation showed significantly better results than sole dorsal instrumentation.