Hakan Ozalp

Nanoparticle silver ion coatings inhibit biofilm formation on titanium implants

The formation of bacterial biofilm on the surface of implanted metal objects is a major clinical problem. The antibacterial and antifungal effect of silver ions has been long known, and seems to give silver the capability to inhibit biofilm formation. To test the effect of silver ions, 20 New Zealand rabbits had bacteria applied to a screw insertion site at the iliac crest, and were then randomly divided into two groups: Group I, which had silver-coated screws applied, and Group II, which had uncoated titanium screws. After the rabbits were sacrificed on day 28, we examined the screws, the bone adjacent to the screws, and the liver, kidneys, brain and corneas of both groups under transmission (TEM) and scanning electron microscopy (SEM). We also analysed microbiological samples from the screw holes. All silver-coated screws, but only 10% of uncoated titanium screws, were sterile. All tissue samples appeared ultrastructurally normal in both groups. Biofilm formation was inhibited on all silver-coated screws, but all uncoated screws developed a biofilm on their surfaces. Our findings suggest that nanoparticle silver ion-coated implants are as safe as uncoated titanium screws and that they can help prevent both biofilm formation and infection.

Experimental Evaluation of the Developmental Mechanism Underlying Fractures at the Adjacent Segment.

BACKGROUND Compression fractures at adjacent mobile segments have been reported as adjacent segment disease under trauma in several studies. In this study, the occurrence of fractures at the adjacent segment was evaluated experimentally under trauma. METHODS Static testing of different fixation systems was performed to show their biomechanical performances. The ovine vertebrae fixed with rigid, dynamic, and semirigid systems were used as test samples. The stiffness values of the systems were obtained by testing the vertebrectomy models under compression bending, lateral bending, and torsion tests. In addition, their effects on the adjacent segments were experimentally evaluated within a drop mechanism. A free-fall drop mechanism was designed and manufactured. Next, 3.5-kg, 5-kg, and 7-kg weights were released from 1 m above the test samples to generate compression fractures. The occurrence of compression fractures was observed with the use of radiograph of test samples, which were obtained before and after the drop test. RESULTS Dynamic and semirigid systems have advantages compared with rigid systems as the result of their lower stiffness values. Radiographs showed that epiphysis fractures occurred at fixed and adjacent mobile segments, which were fixed with semirigid fixation. In addition, dynamic fixation well preserved the fixed and adjacent mobile segments under trauma. CONCLUSIONS The dynamic system with a polyetheretherketone rod can better preserve both adjacent and fixed segments. However, because of the cantilever beam effect, the semirigid system exhibits a great disadvantage.

Biomechanical comparison of transdiscal fixation and posterior fixation with and without transforaminal lumbar interbody fusion in the treatment of L5–S1 lumbosacral joint

Transdiscal screw fixation is generally performed in the treatment of high-grade L5–S1 spondylolisthesis. The main thought of the study is that the biomechanical performances of the transdiscal pedicle screw fixation can be identical to standard posterior pedicle screw fixations with or without transforaminal lumbar interbody fusion cage insertion. Lumbosacral portions and pelvises of 45 healthy lambs’ vertebrae were dissected. Animal cadavers were randomly and equally divided into three groups for instrumentation. Three fixation systems, L5–S1 posterior pedicle screw fixation, L5–S1 posterior pedicle screw fixation with transforaminal lumbar interbody fusion cage insertion, and L5–S1 transdiscal pedicle screw fixation, were generated. Axial compression, flexion, and torsion tests were conducted on test samples of each system. In axial compression, L5–S1 transdiscal fixation was less stiff than L5–S1 posterior pedicle screw fixation with transforaminal lumbar interbody fusion cage insertion. There were no significant differences between groups in flexion. Furthermore, L5–S1 posterior fixation was stiffest under torsional loads. When axial compression and flexion loads are taken into consideration, transdiscal fixation can be alternatively used instead of posterior pedicle screw fixation in the treatment of L5–S1 spondylolisthesis because it satisfies enough stability. However, in torsion, posterior fixation is shown as a better option due to its higher stiffness.

The Predictability Precision of Superior Semicircular Canal Through Radiological Assessment and Microanatomical Dissection

OBJECTIVE There is still ongoing research on the relationship of arcuate eminence (AE) and superior semicircular canal (SSC). We aimed to evaluate the precision of predictability of SSC through the morphology of AE via radiological means. MATERIALS AND METHODS This investigation is performed on 12 dry skulls belonging to Mersin University Medical Faculty department of anatomy. Computed tomography (CT) assessment is performed with 0.5-mm-thin sections temporal bone algorithm on dry skulls which were marked with fixated copper wire by scotch tapes on the most prominent part of the middle fossa floor assuming the location of AE. The data are reformatted on the workstation with vitrea 2.0. The distances of the determined three points including lateral (A), apical (B), and medial (C) of the SSC and the copper wire are measured radiologically. Also, the height between the most apical part of the SSC to the floor of the skullbase (H) is measured. The angles between the placed copper wires and the SSC (E) are calculated. The angle between SSC and the midpoint of the IAC (F) and SSC to the sulcus of the greater GSPN (G) were measured. The nearest distance was measured between the most posterior part of the SSC and the point marked by the perpendicular line drawn from the medial border of the petrous bone to the most posterior part of the internal auditory canal (IAC) (D). RESULTS The right and left A, B, and C distances are 2.54+/- 2.75, 3.67+/-3.16, 5.85+/-3.77; 2.92+/-2.24, 3.68+/-2.93, 6.09+/-3.40, respectively. We could not find any statistical significance when the right A, B, and C distances were compared with the left values. Examination of the values revealed that C distance is greater than the A distance of the same side both for right (p=0.040) and left (p=0.022) measurements. The calculated left and right E angles are 30.313+/-12.838, and 35.558+/-18.437 degrees, respectively. Statistical significance was not found between the right and left angles. The right and left F, G angles were 53.17, 47.25; 93.58, 100.92 degrees; and D distances are 8.01, 8.13 millimeters, respectively. Statistical significance was not found when right and left E, F, G angles and D distances were compared. Among 12 left and 12 right sides, the copper wire was found to be nearly overlapping to SSC in two in the right and only one in the left. CONCLUSION This study reveals that there is a great variability predicting the exact location of SSC through the prominence of AE. Complementary studies are needed with greater number of dry skulls and cadavers. Comparison of different hypothesis including the effect of temporal lobe sulcus is to be discussed to better enlighten the exact relationship of the aforementioned anatomical structures.

Early diagnosis of Grisel’s syndrome in children with favorable outcome

PurposeThe painful torticollis only itself may be a major sign for the diagnosis of Grisel’s syndrome (GS). It is known as an inflammatory atlantoaxial rotatory subluxation following upper respiratory tract infections (URTI) and surgical otolaryngological procedures.Patients and methodsThe analysis of 16 pediatric GS patients were reviewed retrospectively by considering the diagnosis, the treatment modality, and the prognosis at the Department of Neurosurgery and Otorhinolaryngology in Mersin University, Faculty of Medicine between 2008 and 2018. In addition to the clinical cases, five cadavers were used to demonstrate atlantoaxial region, particularly the ligamentous complex and articulation of the atlas-axis, for the mechanism of these rare entities.ResultsThe most common etiological factor of GS was URTI with 81.25% among 16 patients. Painful torticollis was the primary symptom of pediatric patients at admission. The X-Ray, computerized tomography (CT), and magnetic resonance imaging (MRI) investigations were used for the definitive diagnosis in the first week of admission, except one. No morbidity, mortality, and deformity were reported in this series.ConclusionsEarly diagnosis is the principle of GS for avoiding of permanent neck deformity and complex surgical procedures. If GS can be diagnosed without any doubt by only considering patient’s history and clinical examination, CT scan is not recommended due to harmful effects of radiation. The treatment was achieved by reduction, external fixation under analgesia, or sedoanalgesia accompanying with antibiotic and anti-phylogistic treatment.

Brief report: Large fusiform aneurysm of a ircumflex branch of the posterior cerebral artery

We report on a large fusiform aneurysm in a 20-year-old male with a history of cerebral palsy. Aneurysm location relative to four anatomical posterior cerebral artery segments dictates which approach should be used for treatment: pterional transsylvian, subtemporal, or parietooccipital interhemispheric transtentorial approach. A right temporal craniotomy via a subtemporal approach was performed and used to expose the right P1 and P2 segments of the posterior cerebral artery and the posterior communicating artery. Due to significant collateral circulation between the circumflex posterior cerebral artery and superior cerebellar artery branches, trapping of a fusiform aneurysm can be safely achieved without significant deficit.

A rare cause of pleural effusion; cerebrospinal fluid leakage

Dear Sir, Although firearm injuries are rare among penetrating traumas in children, they are very important in terms of their complications. Many thoracic complications may arise during spinal trauma caused by gunshot wounds.[1] Cerebrospinal fluid (CSF) leak is one of the serious complications of gunshot wounds.[1] Here, we present a 10‐year‐old girl admitted to our Pediatric Intensive Care Unit with spinal trauma after being shot on the shoulder.

Reconstruction of a Marjolin Ulcer Defect of the Scalp Invading Brain and Causing Brain Abscess Formation Using Free Latissimus Dorsi Flap

Marjolin ulcers are known as aggressive malignant tumors that mostly arise over chronic wounds and cutaneous scars. Brain abscess is a serious medical condition that requires surgical drainage along with antibiotic treatment. Here, we report a case with a Marjolin ulcer located over the right parietal bone with intracranial abscess formation along with tumor invasion into brain parenchyma. This patient was a 64-year-old man and had a 4 × 4 cm open wound on his scalp from which a purulent discharge was coming. This wound required surgical excision with security margins, resection of bone, evacuation of the cystic cavity, and excision of the walls of the cystic cavity, which were invaded by the tumor. Duraplasty and reconstruction of the defect with a free lattisimus dorsi flap are performed. To the best of our knowledge, the case reported here is unique because of the formation of brain abscess in the background of a long-lasting Marjolin ulcer invading brain parenchyma. It must be remembered that on the background of cutaneous scars located over the scalp, a Marjolin ulcer may develop, and if left untreated, tumor cells may invade even the brain parenchyma. Long-term asymptomatic brain infections may also accompany the given scenario, and complicate differential diagnosis.

Grisel's syndrome accompanying a submandibular abscess.

Grisel’s syndrome (GS) is the non-traumatic atlantoaxial joint subluxation firstly described by Pierre Grisel in 1951 in two patients with pharyngitis. Traumatic subluxations or underlying bone diseases are not considered as GS. It is mostly seen in the pediatric age group. Upper respiratory tract infections and common otolaryngologic surgical procedures such as adenotonsillectomy are predisposing factors. Delayed diagnosis can cause neurological sequela and may need neurosurgical interventions such as posterior arthrodesis. In case of GS seen after upper respiratory tract infections, presenting symptoms include fever, torticollis, and pain during head maneuvers. GS seen after adenotonsillectomy needs meticulous suspicion, because torticollis and pain in neck movements can be attributed to postoperative pain which can lead to delayed diagnosis. Since the cor-