Ahmet Karakasli

Dermal argyria: Cutaneous manifestation of a megaprosthesis for distal femoral osteosarcoma

We present a patient with dermal argyria as a cutaneous manifestation of a silver-coated megaprosthesis used for a distal femoral osteosarcoma. Histological and electron microscopic analyses also showed silver deposition in the dermis.

Combination of anatomical locking plate and retrograde intramedullary nail in distal femoral fractures: comparison of mechanical stability.

OBJECTIVES This study aims is to investigate mechanical properties of intramedullary (IM) nailing and anatomical locking plate in a bone model based on the hypothesis that their combined usage increases safety of fixation stabilization. MATERIALS AND METHODS Twenty-one left distal femoral fracture models were used in the study. Bones were divided into three equal groups. Group 1 specimens were fixed laterally by distal femoral anatomical locking plate. Group 2 specimens were fixed with retrograde distal femoral IM nail. Group 3 specimens were fixed with both distal femoral anatomical locking plate and retrograde distal femoral IM nail. In mechanical tests, alterations in axial loading, torsion angles, and load to failure values were measured and compared between groups. RESULTS Compared to group 1, group 2 was relatively more resistant in axial load tests (p=0.225), and significantly more resistant in load to failure tests (p=0.048). Group 1 was relatively more resistant in torsional load tests (p=0.949) compared to group 2. Group 3 was significantly more resistant than group 1 in axial (p=0.001), torsional (p=0.012) load tests and load to failure tests (p=0.008). Group 3 was significantly more resistant compared to group 2 in axial (p=0.003), torsional (p=0.008) load tests, and relatively more resistant (p=0.059) in load to failure tests. CONCLUSION Thanks to its high mechanical strength and early mobilization capability, distal femoral anatomical locking plate and IM nail combination might be a choice of treatment in complicated osteoporotic or distal femoral fractures from high-energy trauma in young adults.

Pseudomyogenic (Epithelioid sarcoma-like) hemangioendothelioma with bone invasion.

AIM Pseudomyogenic (epithelioid sarcoma-like) hemangioendothelioma is a rare local aggressive vascular tumor. Herein we present a 54-year-old male patient with a tumor on his index finger. CASE The patient presented with a 1-year history of pain and swelling that progressively exacerbated. Bone invasion was observed on the middle phalanx via direct radiography. Histopathological examination findings were compatible with epithelioid sarcoma-like hemangioendothelioma. CONCLUSION To the best of our knowledge is the first case report of epithelioid sarcoma-like hemangioendothelioma with bone invasion.

Are pedicular screws and lateral hook screws more resistant against pullout than conventional spinal hooks and screws in terminal vertebral segment fixation

OBJECTIVES This study aims to biomechanically evaluate and compare four well-known types of terminal spinal constructs to a novel construct composed of a transpedicular screw with a lateral hook screw in terms of axial pullout strength in terminal vertebral segment fixation. MATERIALS AND METHODS Forty fresh-frozen lamb spines were divided into five groups with eight spines each. To stabilize the transverse process, a pedicular screw alone was used in group 1, a sublaminar hook alone was used in group 2, a sublaminar hook and a pedicular screw were used in group 3, claw hook alone was used in group 4, and a pedicular screw with a lateral hook screw was used in group 5. Biomechanical tests were performed using an axial compression testing machine and two noncontact camera systems. RESULTS The mean pullout strength value was 927 N for group 1, 626 N for group 2, 988 N for group 3, 972 N for group 4, and 1194 N for group 5. Pullout strength values were statistically significantly higher in groups 3 and 4 compared to groups 1 and 2. There was no statistically significant difference between groups 3 and 4. Pullout strength value of group 5 was statistically significantly higher than the other groups. CONCLUSION Pedicular screw with a lateral hook screw had the highest fixation value. Lateral hook screw may assist to prevent pullout in patients with pullout risk and hyperkyphosis and after hyperkyphosis surgery. Further prospective clinical studies are needed to show the benefit of such a construct in reducing the risk of distal instrumentation pullout.

The effect of laminae lesion on thoraco-lumbar fracture reduction

INTRODUCTION The treatment of fractures involving the lumbar spine has been controversial. Laminae lesion may be complete or of the greenstick type (incomplete). Dural tears and nerve root entrapment may accompany these laminae fractures. The aim of this study is twofold, to assess the effect of different types of laminae fractures on the anteriorvertebral height restoration in upper lumbar burst fractures and to determine the incidences of the intraoperatively detected dural tear and neural entrapment in complete and incomplete laminae fractures to choose the optimal treatment. MATERIALS AND METHODS A retrospective review was conducted on 112 patients with 114 lumbar burst fractures treated operatively, age ranged from 17 to 55 years (mean age 32). Male to female ratio was (93%/7%), 8 females. Patients were divided into three groups, group 1 patients without lamina fracture, group 2 patients with complete type lamina fracture and group 3 patients with (percutaneous) incomplete type lamina fractures. All clinical charts and radiologic data of these groups were analyzed for their association with dural tears, neural entrapment and the impact of lamina fracture (complete and incomplete types) on the efficacy of anterior vertebral height restoration. The severity of injury was determined using the ASIA (Modified Frankel scale). RESULTS Out of 114 upper lumbar burst fractures, lamina fracture occurred in 34 patients (29.8%), complete lamina fracture occurred in 21 patients (61.7%), whereas incomplete lamina fracture occurred in 13 patients (38.3%). Dural tear was detected in 16 patients (47%) and was predominantly higher in complete type lamina fracture 12 patients (57%) when compared to 4 dural tears (30%) in incomplete lamina fractures. Analysis of the data revealed no significant difference in the preoperative anterior vertebral height loss and local kyphotic angle between the three groups. However the anterior vertebral height and local kyhpotic angle restoration were found to be affected by the presence of complete lamina fracture when compared to other groups with incomplete lamina fracture and without lamina fracture (P=0.001). CONCLUSION In upper lumbar burst fractures, complete lamina fracture is an indicator of injury severity. When detected preoperatively on CT or MRI scanning, it should be operated by open book laminectomy even if the patient is neurologically intact since it carries a high risk of neural entrapment, and its presence affects the intraoperative postural and instrumental trials for anterior vertebral height restoration.

Rigid fixation of the lumbar spine alters the motion and mechanical stability at the adjacent segment level.

OBJECTIVES This study aims to examine the motion and stability of the adjacent segment following rigid fixation of the lumbar spine. MATERIALS AND METHODS The study included 17 fresh-frozen lamb lumbar spines (including the sacrum to T12). Biomechanical testing was performed using an axial compression testing machine. Axial compression was applied to all the specimens using a loading speed of 5 mm min-1. A specifically designed fixture was used to generate torque ≤8400 Nmm. The fixture was used with each specimen to achieve flexion and extension, axial neutral compression, and right and left bending. All specimens were tested intact, and again after implantation using posterior pedicle screws and rod fixation. During testing intervertebral displacement at the adjacent level (L5-S1) was recorded continuously via extensometry. RESULTS Axial compression and superior-inferior displacement were lower in the adjacent segment (L5-S1) than anterior-posterior displacement following rigid fixation. Statistical analysis showed that there was a numerical difference and a significant change between the intact spine and the adjacent segment in the axial compression and extension positions (p<0.027). The intact spines demonstrated the maximum displacement and the difference in extension positions were significant (p<0.015). CONCLUSION Rigid fixation of the lumbar spine altered the range of motion at the adjacent segment level. As such, abnormal stress on the adjacent segment causes spinal instability, which may subsequently cause facet joint degeneration and low back pain.

Biomechanical comparison of intact lumbar lamb spine and endoscopic discectomized lamb spine.

OBJECTIVES This study aims to perform a biomechanical comparison of changes on motion segments after minimally invasive percutaneous endoscopically discectomized and intact spine and to investigate the effects of endoscopic discectomy on the lumbar spine of the lamb. MATERIALS AND METHODS Ten fresh-frozen lamb spines were used in this study. Percutaneous endoscopic discectomy was performed on each spine at L4-L5 level. The biomechanical tests for both intact spine and endoscopically discectomized spine were performed by using axial compression testing machine. The axial compression was applied to all specimens with a loading speed of 5 mm/min. 8400 N/mm moment was applied to each specimen to achieve flexion and extension motions, right and left bending through a specially designed fixture. RESULTS In axial compression and flexion tests, the specimens were more stable based on displacement values. The displacement values of discected spines were closer to the values of intact specimens. Comparing both groups, only displacement values of the left-bending anteroposterior test were significant (p≤0.05). CONCLUSION Percutaneous transforaminal endoscopic discectomy (PTED) has no biomechanical and clinical disadvantages. Endoscopic discectomy has also no stability disadvantages. Only anteroposterior displacement values of left bending test were statistically significant. We consider that the reason for such results were due to the fact that PTED was performed on the left side of all specimens.

Iatrogenic lateral meniscus anterior horn injury in different tibial tunnel placement techniques in ACL reconstruction surgery – A cadaveric study

Objectives The aim of this study was to analyze the effect of tibial tunnel positioning in single bundle and double bundle ACL reconstructions on lateral meniscus anterior root. Materials Twelve single knee cadavers were used, 6 for a single bundle ACL reconstruction, which were reamed gradually starting from 8 mm, 9 mm and ended with a 10 mm reamers, while the other 6 were prepared for a double bundle ACL reconstruction in which 7 mm reamer for the AM tunnel and 6 mm reamer for the PL tunnel were used. After drilling, changes of lengths and thicknesses of anterior horns of the lateral menisci were recorded. Results Before drilling, the groups were homogenous for the lateral menisci dimensions. After drilling, no statistically significant difference was noticed between the two groups. However, in single bundle group, 2 anterior horns width injury (1.44 mm and 2.13 mm) with the 9 mm reamer and 3 anterior horns width injury (2.51 mm, 3.55 mm and 4.28 mm) with the 10 mm reamer were recorded. However in double bundle group a single anterior horn width injury (2.82 mm) was recorded. Conclusion Using a greater size reamer in single bundle reconstruction, causes a relatively higher risk of lateral meniscal anterior root injury. Lateral meniscus stability should be examined arthroscopically after reaming with large reamers.

Emergency physicians performed Point-of-Care-Ultrasonography for detecting distal forearm fracture

Objectives Several studies focusing diagnosis of forearm fracture using Point-of-Care-Ultrasonography (POCUS) had been carried out in children. There is a lack of evidence for the utility of sonographic (US) examination for detecting of distal forearm fracture in adults. We aim to determine the diagnostic sensitivity and specificity of POCUS examination for the fracture of the distal radius and ulna in adult patients presenting with blunt forearm trauma. Material and Methods Adult patients presenting with acute distal forearm trauma and suspicion of fracture were enrolled into study. POCUS had been performed by blinded emergency physicians, than anteroposterior and lateral x-rays was obtained. If inconsistency between x-rays and POCUS has been occurred, computed tomography were ordered. Assessment of orthopedic surgeon was accepted as a gold standard diagnosis. Results Ninety three POCUS were performed in 90 patients. Fifty nine radius and 19 ulna fracture had been diagnosed. POCUS detected all radius fracture, but missed 2 ulna fracture. There were 4 false positive results for both radius and ulna with POCUS. X-ray missed 4 radius, and 1 ulna fractures. Diagnostic sensitivity and specificity of POCUS for fracture of ulna were 89.5% (CI%95, 65.5–98.1) and 94.6 (CI%95, 86–98.2), for fracture of radius were 100% (CI%95, 92.4–100), and 88.2%. (CI%95, 71.6–96.1). Conclusion Emergency physician performed POCUS examination is very sensitive and specific the diagnosis of distal forearm fracture. Diagnostic sensitivity of POCUS for radius fracture is higher than x-ray.

The effects of tibiofibularis anterior ligaments on ankle joint biomechanics.

BACKGROUND The aim of this study was to evaluate the biomechanical behavior of anterior inferior tibiofibularis ligament (AITFL) deficient human ankle under axial loading of ankle at stance phase of gait. In order to investigate the contribution of AITFL to ankle stability, an in vitro sequential experimental setup was simulated. METHODS The measurement of posterior displacement of distal tibia and anterior displacement of the foot, in neutral position, secondary to axial compression, was performed by two non-contact video extensometers. Eight freshly frozen, anatomically intact, cadaveric human ankle specimens were included and tested. An axial compression test machine was utilized from 0 to 800 Newtonswith a loading speed of 5 mm/min in order to simulate the axial weight-bearing sequence of the ankle at stance phase of human gait. RESULTS There was a statistically significant difference between anteroposterior displacement values for AITFL-Intact and AITFL-Dissected specimens (p≤0.05). Mean AITFL-Intact and mean AITFL-Dissected ankle anteroposterior displacement was 1.28±0.47 mm and 2.06±0.7 mm, respectively. CONCLUSION This study determined some numerical and quantitative data about the biomechanical properties of AITFL in neutral foot position. In the emergency department, diagnosis and treatment of AITFL injury, due to ankle distortion, is important. In AITFL injuries, ankle biomechanics is affected, and ankle instability occurs.