Convolutional neural network-based automated segmentation and labeling of the lumbar spine X-ray

PURPOSE

This study investigated the segmentation metrics of different segmentation networks trained on 730 manually annotated lateral lumbar spine X-rays to test the generalization ability and robustness which are the basis of clinical decision support algorithms.

METHODS

Instance segmentation networks were compared to semantic segmentation networks based on different metrics. The study cohort comprised diseased spines and postoperative images with metallic implants.

RESULTS

However, the pixel accuracies and intersection over union are similarly high for the best performing instance and semantic segmentation models; the observed vertebral recognition rates of the instance segmentation models statistically significantly outperform the semantic models' recognition rates.

CONCLUSION

The results of the instance segmentation models on lumbar spine X-ray perform superior to semantic segmentation models in the recognition rates even by images of severe diseased spines by allowing the segmentation of overlapping vertebrae, in contrary to the semantic models where such differentiation cannot be performed due to the fused binary mask of the overlapping instances. These models can be incorporated into further clinical decision support pipelines.

Results of Four-Level Anterior Cervical Discectomy and Fusion Using Stand-Alone Interbody Titanium Cages

Study Design

This is a retrospective study with a minimum follow-up of 2 years.

Purpose

The aim of this study is to assess the long-term outcomes after performing the four-level anterior cervical discectomy and fusion (ACDF) in the treatment of degenerative cervical spine disease using stand-alone titanium cages.

Overview of Literature

Over the last decades, a rapid increase in the use of stand-alone cages for ACDF has been observed. However, research on their application in the treatment of four-level diseases is insufficient.

Methods

In this study, 130 patients presenting with symptomatic cervical spondylosis who underwent four-level ACDF using stand-alone cages in our institution between 2008 and 2016 were assessed. Fifty-two patients were women and 78 men with a mean age of 60.5 years. Their clinical and radiological outcomes were assessed. The results of the Neck Disability Index (NDI) and Visual Analog Scale as well as bony fusion were evaluated, and the revisions were analyzed. All of the patients underwent the four-level microscopic ACDF using the same titanium rectangular cage.

Results

The mean follow-up was 47±11.4 months. A fusion of all four levels was achieved in 80.72% of the patients. In 25 patients (19.23%), an incomplete bony bridging was observed in at least one fusion level at the final follow-up. However, only two patients (1.5%) were symptomatic and underwent revision. The mean NDI improved significantly from 39.4±9.3 at presentation to 8.3±6.6 at the final follow-up. Cervical lordosis improved significantly from a mean of 5.5° preoperatively to a mean of 15° postoperatively. Cage sinking and loss of segment height during healing had a mean of 3 mm.

Conclusions

Overall, the application of four-level ACDF using titanium cages in a stand-alone technique has been proven to be a safe and effective treatment method for degenerative disease. In a large cohort, a high rate of good long-term clinical and radiological results was achieved.

Symptomatic Intracranial Hemorrhage after Dural Tear in Spinal Surgery-A Series of 10 Cases and Review of the Literature

OBJECTIVE

Intracranial hemorrhage (IH) after spinal surgery is a rare but potentially life-threatening complication. Knowledge of predisposing factors and typical clinical signs is essential for early recognition, helping to prevent an unfavorable outcome.

METHODS

A retrospective analysis was performed of patients with IH after spinal surgery treated in our institution between 2012 and 2018. The literature dealing with IH complicating spinal surgery was reviewed.

RESULTS

Our investigation found 10 patients with IH (6 female and 4 male). To the best of our knowledge, this is the largest series reported so far. The assumable incidence of IH after spinal surgery in our population was 0.0657%. Durotomy was noticed in 6 patients, all of whom were treated according to a local standard protocol. In 4 patients, the dural tear was occult. Hemorrhage occurred mostly in the cerebellar compartment. Eight of 10 patients had long-standing arterial hypertension, which seems to be a risk factor (hazard ratio, 1.58). Five patients were treated conservatively, whereas 3 required a cerebrospinal fluid (CSF) diversion procedure. In 2 patients, revision surgery with duraplasty was necessary. Seven patients were discharged with little to no neurologic symptoms, and 3 had significant deterioration. One patient died because of brainstem herniation. Review of the literature identified 54 articles with 72 patients with IH complicating spinal surgery.

CONCLUSIONS

Patients with intraoperative CSF loss should be kept under close supervision postoperatively. After opening of the dura, a watertight closure should be attempted. The use of subfascial suction drainage in cases of a dural tear as well as preexistent arterial hypertension seems to be a risk factor for the development of IH. Intracranial bleeding must be considered in every patient with unexplained neurologic deterioration after spinal surgery and should be ruled out by cranial imaging. To ensure early recognition and prevent an unfavorable outcome, a high index of suspicion is required, especially in revision spinal surgery. The treatment is specific to the extent and location of the IH, thus dictating the outcome. In most patients, conservative treatment led to a good outcome. CSF diversion measures may be necessary in patients with compression or obstruction of the fourth ventricle. Large hematomas with mass effect may require decompressive surgery.

Safety and Accuracy of Ultrasound-guided Burr Hole Brain Abscess Aspiration

BACKGROUND

 Ultrasound-guided burr hole biopsies or catheter placements are quick and safe procedures. The use of these procedures for treatment of brain abscesses has been reported, but larger series are missing. The aim of our study was to evaluate the accuracy and safety of the methods.

PATIENTS

 Twenty-five brain abscess aspirations in 17 patients were analyzed. Fourteen procedures were performed to evacuate abscesses in eloquent regions; another 3 were located deeply in the cerebellar hemispheres.

RESULTS

 In all the procedures, a histopathologic diagnosis could be established. Only one transient deterioration of a hemiparesis occurred; other operative complications were not observed. Six patients needed more than one operation due to a relapse of the abscess. Two out of three cerebellar abscesses could be cured with one aspiration. Thirteen patients had an excellent outcome, and 2 remained severely disabled. One patient died from cerebritis and another from a neoplasm. In every procedure, a proper visualization of the abscess and monitoring of the penetration and aspiration could easily be performed.

CONCLUSION

 Ultrasound-guided burr hole aspiration is minimally invasive, quick, and has a very low complication rate. It offers the advantage to adapt to intraoperatively changing anatomy. The rate of recurrence is not lower than in other treatment modalities.

Reoperation rate after anterior cervical discectomy and fusion using standalone cages in degenerative disease: a study of 2,078 cases

BACKGROUND CONTEXT

Over the last two decades, there has been a rapid increase in the use of cervical spine interbody fusion cages. Reoperation rate remains an important determinant of procedural efficacy and safety.

PURPOSE

To evaluate the rate and reasons for reoperations in cervical spondylosis patients undergoing anterior decompression and fusion using stand-alone cervical interbody fusion cages.

STUDY DESIGN

A retrospective study of 2,078 consecutive cases of degenerative cervical spine disease undergoing fusion using stand-alone cages.

PATIENT SAMPLE

Between January 2005 and December 2014, 2,078 patients underwent anterior cervical decompression and fusion using stand-alone cages in our institution.

OUTCOME MEASURES

The reoperations were analyzed and classified into early (during the first 90 days postoperatively) and late (after 90 days) reoperations. The rate and the causes of reoperation in both groups were reported and the results were compared.

METHODS

In 1,558 patients, a short segment fusion (≤2 levels) was performed, while the remaining 520 patients underwent a long segment fusion (≥3 levels).

RESULTS

The overall incidence of reoperation was 5.63%. The rate of early reoperations was 2.07%, mostly due to postoperative hematoma, and the rate of late reoperations was 3.56%, mostly due to adjacent segment disease. Revision due to pseudarthrosis was performed in 0.58% of cases. The early reoperation rate was significantly higher in the group with a long segment fusion, while the late reoperation rate was significantly higher in patients undergoing a short segment fusion.

CONCLUSION

Following anterior cervical decompression and fusion with a stand-alone cage, the overall incidence of symptomatic pseudarthrosis is low. Patients undergoing long segment fusion should be closely observed in the early postoperative period as they have a higher early complication rate. On the other hand, long segment fusions have a lower incidence of adjacent segment disease over the years.

Surgical treatment of type II odontoid fractures in elderly patients: a comparison of anterior odontoid screw fixation and posterior atlantoaxial fusion using the Magerl-Gallie technique

PURPOSE

This single-centre retrospective study compared anterior odontoid screw fixation and posterior atlantoaxial fusion in the surgical treatment of type II B odontoid fractures according to Grauer in elderly patients.

METHODS

Between 1994 and 2014, 133 consecutive patients above 60 years presenting with type II B odontoid fracture were treated surgically in our department. They were divided retrospectively into two groups. Group A included 47 patients in whom anterior odontoid screw fixation was performed. Group B with 86 patients underwent posterior atlantoaxial fusion. The clinical and radiological data were analysed. Any reoperation during the follow-up was recorded and evaluated.

RESULTS

The mean age in group A (74.19 years) was significantly less than in group B (78.16 years). The mean operative time in group A (64.5 min) was significantly shorter than in group B (116 min). Again, the mean amount of blood loss in group A (79 ml) was significantly less than in group B (379 ml). The mean postoperative hospital stay was significantly shorter in group A (17.4 days) than in group B (30 days). The mean follow-up was 29.3 months in group A and 32 months in group B. The rate of pseudoarthrosis was significantly higher in group A (25.5%) than in group B (3.5%). Furthermore, the need for revision surgery was significantly increased in group A (23.4%) than in group B (10.47%).

CONCLUSIONS

Odontoid screw fixation is a less invasive surgery for type II B odontoid fractures in elderly patients. However, posterior atlantoaxial fusion provides a superior surgical outcome regarding fracture healing and the need for surgical revisions. These slides can be retrieved under Electronic Supplementary Material.

[Surgical management of ankylosing spondylitis (Bechterew's disease)]

Ankylosing spondylitis is an inflammatory rheumatic disease that is often associated with back pain and restricted spinal movement. In the later stages of the disease, complete ossification of the entire spine and severe deformity can occur, often resulting in a marked reduction in quality of life and an increased risk of loss of independence due to diminished visual field. Patients with ankylosing spondylitis are at greater risk of spinal fractures. These are generally complex fractures associated with high morbidity and mortality; in addition, neurological deficits are not unusual. Conventional radiological diagnosis is often insufficient to establish a diagnosis. Conservative treatment of fractures of the spine in this patient group is unsatisfactory. Surgical procedures, if necessary combined with decompression, are often the preferred treatment of choice in the fractured or malaligned ankylosed spine. Rebalancing of the sagittal profile with normalization of the visual axis and an improvement of quality of life is achieved through corrective osteotomies. Despite the high rate of complications, long-term results following spinal surgery in patients with ankylosing spondylitis are good. Minimally invasive surgery is appropriate for a further reduction in the complication rate. Meticulous preoperative planning is essential in the treatment of patients with ankylosing spondylitis.

Real-time ultrasound monitoring during intracranial needle biopsies: operative results and detection of complications in 100 cases

OBJECTIVE

Intraoperative ultrasound displays dynamic processes intraoperatively. Performing burr-hole biopsies under a real-time visual control is an interesting option for the neurosurgeon. However, the percentage of conclusive diagnoses obtained by this technique and the rate of complications must be evaluated in a larger series.

METHODS

One hundred consecutive intracranial biopsies were analyzed. Through a burr hole, the lesion was localized by ultrasonography, and the planned needle trajectory was superimposed onto the image. Intracranial vessels were imaged by Doppler flow signals. Biopsies were taken in a mean depth of 41 mm (maximal 65 mm) from different parts of each tumor.

RESULTS

Thirty-six lesions involved the corpus callosum, 16 lesions were located deeply within the white matter, five in the internal capsule, and one in the upper brainstem. There were three cerebellar and 17 temporal lesions. Ten tumors did not exceed a diameter of 15 mm in any plane. The mean time interval from skin incision to the end of suturing was 45 minutes, and the mean time from the surgeons entering the operating theater to leaving the theater was 63 minutes. In 95% of the lesions, a diagnosis could be established. Transient neurologic deficits occurred in five patients, which were permanent in three. In 42 patients without postoperative neurological symptoms, postoperative computed tomography scans were obtained within 24 hours; a visible hemorrhage occurred in eight (19%), six of which were seen intraoperatively.

CONCLUSION

When intraoperative ultrasound-navigated biopsies were used they obtained a similar percentage of conclusive diagnoses as stereotactic biopsies. The complication rate is comparable as well. Emerging intracranial complications such as hemorrhages can be observed. However, their incidence cannot be decreased.

Intra-operative diagnosis and image-guided management of an intracerebral haemorrhage occurring during ultrasound-guided biopsy

Haemorrhagic complications occurring after burr-hole procedures are diagnosed only in symptomatic patients or when postoperative imaging is performed routinely. We report the development of an intracerebral haematoma which occurred during ultrasound-guided burr-hole biopsy. Real-time ultrasound through the same burr-hole enabled us to determine the dynamics of the bleeding and its terminal volume. The operation was finished without further complications and the patient did not experience an impairment of her neurological state. Intra-operative ultrasound is capable of detecting "invisible" complications during burr-hole procedures.