Electromagnetic navigation reduces radiation exposure for retrograde drilling in osteochondrosis dissecans of the talus.

BACKGROUND: Retrograde drilling in osteochondrosis dissecans (OCD) is a widely used surgical intervention. A radiation-free electromagnetic navigation system (ENS)-based method was compared with the standard freehand fluoroscopic (SFF) method regarding clinical applicability. METHODS: We performed a clinical cohort study at a department of Orthopaedics in a Level 1 children's hospital with 40 patients (20 SFF and 20 ENS). Retrograde drilling of the talar dome was used in patients with unstable medial OCD (MRI stage 2 according to Hepple's revised classification; stage 2 according to the International Cartilage Repair Society). The outcome measurements were: (a) Intraoperative fluoroscopy exposure and length of surgery and (b) Postoperative serial follow-up MRIs every 6 months. RESULTS: 22 female and 18 male patients aged 13.8 ± 1.6 years (range: 11-17 years) were included. Using the ENS technique, length of surgery was significantly reduced to 20.2 ± 6.4 min compared to 36.1 ± 11.8 min (p < 0.01) for the SFF technique. The average x-ray radiation time for the SFF technique was 23.5 ± 13.5 sec and 1.9 ± 1.7 sec for the ENS technique (p < 0.01). Radiation exposure was significantly reduced from 44.6 ± 19.7 mSv (SFF technique) to 5.6 ± 2.8 mSv (ENS technique) (p < 0.01). Intraoperative perforation of cartilage occurred once in the SFF group. Correct placement of the drilling channel was verified in all patients on follow-up MRI after six months and a timely healing was seen after two years. CONCLUSIONS: The ENS method provides for a significant reduction in length of surgery and radiation exposure. ENS was without intraoperative cartilage perforation. The clinical and radiological follow-up parameters are comparable for SFF- and ENS-guided retrograde drilling. TRIAL REGISTRATION: WF - 085/20, 05/2020 "retrospectively registered" https://www.aerztekammer-hamburg.org/ethik_kommission.html .

Routine use of perfusion computed tomography for the detection of delayed cerebral ischemia in unconscious patients after aneurysmal subarachnoid hemorrhage.

BACKGROUND: Delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) is difficult to diagnose in unconscious patients, but it is essential for the prognosis. We analyzed the diagnostic value of routinely performed perfusion computed tomography (rPCT) to detect DCI-related hypoperfusion in this subgroup of patients. METHODS: Retrospective analysis of unconscious aSAH patients who underwent rPCT according to a predefined protocol. We exclusively analyzed PCT examinations in patients who were clinically and functionally asymptomatic with regard to transcranial Doppler ultrasound (TCD) and invasive neuromonitoring at the time of the PCT examination. The perfusion maps were quantitatively evaluated to detect DCI-related hypoperfusion. Possible clinical risk factors for the occurrence of DCI-related hypoperfusion in rPCT imaging were analyzed by multivariate analyses. RESULTS: One hundred thirty-six rPCTs were performed in 55 patients. New onset of DCI-related hypoperfusion was observed in 18% of rPCTs. The positive predictive value of rPCT to detect angiographic CVS was 0.80. Between examination days 6 and 10, the rate of DCI-related hypoperfusion was increased significantly (p < 0.05). After rPCT imaging with proof of DCI-related hypoperfusion, short-term follow-up showed secondary cerebral infarction (SCI) in 38%, compared with 5% for patients with normal perfusion on rPCT. The parameters "high risk phase (examination days 6-10)" and "new onset of DCI-related SCI" were significantly associated with the occurrence of DCI-related hypoperfusion in rPCT. CONCLUSIONS: In unconscious and asymptomatic aSAH patients, rPCT identifies DCI-related hypoperfusion in a relevant number of examinations. However, despite timely endovascular rescue therapy, a significant proportion of secondary infarction still occurs in this subgroup.

Clusters of spreading depolarizations are associated with disturbed cerebral metabolism in patients with aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: We studied the dynamics of extracellular brain tissue concentrations of glucose, lactate, pyruvate, and glutamate during the occurrence of spreading depolarizations (SDs) in patients with aneurysmal subarachnoid hemorrhage. METHODS: In this prospective observational study, patients with aneurysmal subarachnoid hemorrhage received multimodal cerebral monitoring, including intracranial pressure, cerebral microdialysis, and subdural electrocorticography. RESULTS: Seven of the 17 recruited patients had intracerebral hemorrhage, acute ischemia and severe brain oedema leading to acute ischemic neurological deficits associated with early disturbance of metabolism at the recording site. They displayed a total of 130 SDs. The remaining 10 patients without acute ischemic neurological deficits exhibited 138 single SDs and 68 SDs in clusters. In patients without acute ischemic neurological deficits, clustered SDs were associated with a significant transient decrease in glucose and increase in lactate compared with baseline during the first 140 minutes after SDs. Moreover, the number of clustered SDs correlated with the outcome (R=-0.659; P<0.01). CONCLUSIONS: SDs can propagate in nonischemic human brain tissue. Clusters of SDs are related to metabolic changes suggestive of ongoing secondary damage in primarily nonischemic brain tissue.

Does Juvenile Idiopathic Arthritis Affect the Course of Legg-Calvé-Perthes Disease? A Case-Control Study with a Mean Follow-Up of 8 Years.

BACKGROUND: This study aimed to determine the clinical and radiological course in children who had Legg-Calvé-Perthes disease (LCPD) associated with juvenile idiopathic arthritis (JIA). METHODS: In a retrospective chart review between 2007 and 2019, eight consecutive JIA patients diagnosed with concomitant LCPD were identified and compared with a case-control group of 10 children with LCPD only. RESULTS: LCPD was diagnosed at a mean age of 8.1 years (3.0-14.7) in children with JIA as compared to 6.1 years (2.9-10.0) in controls. According to the modified Harris Hip Score (mHHS), four children with JIA and all controls had an excellent result. Regarding the fragmentation severity and the duration of each stage, we found no differences using the lateral pillar and modified Elizabethtown classification. Five hips were classified as Stulberg I/II, two hips as Stulberg III, and one hip as Stulberg V with no evidence of hip dysplasia or severe overcoverage in either group. CONCLUSIONS: The radiological outcome of LCPD did not differ between both groups, while the clinical outcome was slightly better in controls. Physicians should be aware that children with LCPD may have JIA too. In suspicious cases, further investigations are recommended, and patients should be referred to pediatric rheumatologists.

Cerebral Vasospasm After Spontaneous Subarachnoid Hemorrhage: Angiographic Pattern and Its Impact on the Clinical Course.

OBJECTIVE: To analyze angiographic characteristics of cerebral vasospasm (CVS) after spontaneous subarachnoid hemorrhage (sSAH) and their potential impact on secondary infarction and functional outcome. METHODS: Demographic, clinical, and imaging data of sSAH patients with angiographic CVS admitted over a 6-year period were retrospectively analyzed. RESULTS: A total of 85 patients were included in the final analysis. A total of 311 arterial territories in 85 angiographies demonstrated angiographic CVS. The anterior cerebral artery (ACA) was the most common site of angiographic CVS (42.1%), followed by the middle cerebral artery (MCA) (26.7%). In 29 angiographies (34%) CVS was found in more than 3 vessels and a bilateral pattern was identified in 53 cases (62%). Older age (OR 3.24 [95% CI 1.30-8.07], P = 0.012) was identified as the only significant risk factor for CVS-related infarction (OR 22.67, P = 0.015). Unfavorable outcome was associated with older age (OR 3.24, P = 0.023) and poor World Federation of Neurosurgical Societies grade (OR 3.64, P = 0.015). Analyses of angiographic characteristics did not reveal any risk factors for unfavorable outcome. We identified distal CVS as a significant risk factor for CVS-related infarction (OR 2.89, P = 0.026). CONCLUSIONS: Angiographic CVS after sSAH shows a specific distribution pattern in favor of ACA and MCA and in most cases 2-3 affected vessels are affected, often bilaterally. Patients exhibiting distal CVS have a higher risk for CVS-related infarction and should be observed closely. Nonetheless, the majority of angiographic characteristics did not allow conclusions about functional outcome nor the occurrence of CVS-related infarction in sSAH patients.

Preliminary evidence that ketamine inhibits spreading depolarizations in acute human brain injury.

BACKGROUND AND PURPOSE: Spreading depolarizations, characterized by large propagating, slow potential changes, have been demonstrated with electrocorticography in patients with cerebral hemorrhage and ischemic stroke. Whereas spreading depolarizations are harmless under normal conditions in animals, they cause or augment damage in the ischemic brain. A fraction of spreading depolarizations is abolished by N-methyl-d-aspartate receptor antagonists. Summary of Case- In 2 patients with severe acute brain injury (traumatic and spontaneous intracranial hemorrhage), spreading depolarizations were inhibited by the noncompetitive N-methyl-d-aspartate receptor antagonist ketamine. This restored electrocorticographic activity. CONCLUSIONS: These anecdotal electrocorticographic findings suggest that ketamine has an inhibitory effect on spreading depolarizations in humans. This is of potential interest for future neuroprotective trials.