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.

Atlantoaxial instability after a header in an amateur soccer player.

STUDY DESIGN: Case report and literature review. OBJECTIVE: To report a unique case of atlantoaxial instability after a header in a 37-year-old amateur soccer player and to discuss the injury pattern in relation to the impact of heading. SUMMARY OF BACKGROUND DATA: Although there is potential for cervical spine injuries, the rates in soccer are low compared with other contact or even noncontact sports. No cases of acute post-traumatic atlantoaxial instability after heading have ever been reported in a MEDLINE-listed article. METHODS: A 37-year-old male soccer player experienced acute upper neck pain and transient quadriplegia after heading a long-distance ball on 2 occasions during a match. Imaging revealed atlantoaxial instability. Persistent neurological symptoms on conservative treatment led to his referral to our department. The considerable instability required surgical intervention. RESULTS: Transarticular C1-C2 fixation and posterior fusion with structural iliac crest grafting were performed. The procedure immediately led to complete relief of the neurological symptoms. After an uneventful postoperative recovery, follow-up at 9 months revealed solid fusion. The patient remained symptom free. CONCLUSION: Heading the ball in soccer can potentially lead to atlantoaxial instability. Ligamentous damage can theoretically be caused by anteriorly directed and rotational overload. However, the causative mechanism remains unclear. Diagnostic workup should consider dynamic imaging in players with transient neurological symptoms after minor trauma to the cervical spine. LEVEL OF EVIDENCE: N/A.