Endre Varga

Putative proprioceptive function of the pelvic ligaments: biomechanical and histological studies.

The sacrospinous (SS) and sacrotuberous (ST) ligaments of the pelvic ring are known as mechanical stabilisers of the pelvic girdle, primarily against rotational forces in the sagittal and horizontal planes. Earlier studies, however, raised the possibility that ST/SS ligaments possess significant proprioceptive function, while the mechanical role of these ligaments in maintaining the structural integrity of the pelvis is of less importance. The aim of this study is to determine whether the function of these ligaments is strictly to provide mechanical stability or if they have any additional functional properties, i.e., proprioception. In order to reveal the function of the SS/ST ligaments, biomechanical studies of cadaver pelvis were used along with the histological analysis of the ligaments. Following measurements to determine the accurate mechanical role of the pelvic ligaments, the strength of these ligaments was significantly less than we earlier expected. For this reason other functions of the SS/ST ligaments were considered, including the proprioceptive role. Indeed, histological studies revealed ramifying nerve terminals in the SS/ST ligaments. These terminals may represent the morphological substrate of the proprioceptive function associated with the ligaments. Our studies revealed that SS/ST ligaments might have a significant proprioceptive function providing information of the position of the pelvis. Consequently, the mechanical role of the ligaments in maintaining the structural integrity of the pelvis may be significantly less than previously assumed. Understanding the function of the SS/ST ligaments is crucial for providing more precise guidelines for patient management with injuries to the posterior pelvic region.

Correction of a severe facial asymmetry with computerized planning and with the use of a rapid prototyped surgical template: a case report/technique article.

Management of significant facial asymmetry presents a challenge due to the geometric complexity of the bony and other facial structures. Manual model surgery is an essential part of treatment planning but it can be complicated, time-consuming and may contain potential errors. Computer-aided surgery has revolutionized the correction of maxillofacial deformities. The aim of this study was to report a case of facial asymmetry when computerised simulation surgery was performed instead of manual model surgery and a virtually planned wafer splint was fabricated. A 26-year-old male was presented with a severe right-sided hemimandibular elongation. Following presurgical orthodontics high-resolution computer tomography scan was performed. The stack images were reformatted into a three-dimensional structure. Virtual Le Fort-I osteotomy was performed and the symmetry of the maxilla was corrected with the help of a three-dimensional planning software. A virtual intermediate surgical wafer was designed and produced with three-dimensional rapid prototyping technology. The mandible was rotated into the correct position following virtual bilateral sagittal split osteotomy to visualize the movements of the osteotomised mandibular segments. The two-jaw procedure was performed according to the virtual plan. The facial symmetry was improved significantly and stable occlusion was achieved. This complex case shows the advantages of computer-aided surgical planning and three-dimensional rapid prototyping for the correction of facial asymmetries.

Severe Pelvic Bleeding: The Role of Primary Internal Fixation.

Pelvic ring injuries form part of the spectrum of polytraumaandmust be considered a potentially lethal injury with mortality rates of 10–20%. The stabilization of the unstable pelvic ring in acute resuscitation of multiply injured patients is now conventional wisdom.We aimed: (1) to design a new iliosacral (IS) screw, (2) to prove the clinical advantages of this new implant, and (3) to work out the optimal surgical strategy using this implant. Taking the demands of the above mentioned data into account, a 10 mm 2.8 mm-cannulated iliosacral screw seemed to be optimal for the special requirements. Before industrial production, finite element analysis (FEA) was performed to find out whether these screws would be enough to stabilize the posterior pelvic ring alone or not. Clinical experience led to the modification of the set of instruments, which finally yielded handy tools and implants. Building further on the surgical skills and experiences gained (by the surgeons and the O.R. personnel), we increased our capacity to perform more and more immediate pelvic fixations. Emergency pelvic stabilizationswere performed in patientswith pelvic injuries who had hemodynamic instability, despite immediate shockmanagement during the diagnostic period. During thelast eleven years, 244 patientswith Tile B3 and Cpelvic injuries have been stabilized with 10-mm diameter cannulated IS screws percutaneously posteriorly. Fortyeight hemodynamically unstable patientswere stabilized in the first 2 h with iliosacral screw fixation. The percutaneous pelvic ring stabilization with 10-mm cannulated screws provedstrongenoughin bothersome casesaswell.

Effect of the Combination of Low-Speed Drilling and Cooled Irrigation Fluid on Intraosseous Heat Generation During Guided Surgical Implant Site Preparation: An In Vitro Study

Purpose: Investigating the effect of the combination of low-speed drilling and cooled irrigation fluid on intraosseous temperature rise during guided and freehand implant surgery. Materials and Methods: Bovine ribs were used as bone specimens. Grouping determinants were as follows: drill diameter (2.0, 2.5, 3.0, and 3.5 mm), irrigation fluid temperature (10°C, 15°C, and 20°C), and surgical method (guided and freehand). Drilling speed was 800 rpm. Results were compared with previous ones using 1200 rpm. Temperature measurements were conducted using K-type thermocouples. Results: No mean temperature change exceeded 1.0°C if irrigation fluid cooled to 10°C was used, regardless of the drill diameter or the surgical method, with the highest elevation being 2.10°C. No significant reduction was measured when comparing groups using 15°C and 20°C irrigation fluids, regardless of both drill diameter and surgical method. Conclusion: The use of irrigation fluid being cooled to 10°C combined with low-speed drilling (800 rpm) seems to be a safe method for implant site preparation and drilling through a drilling guide in terms of temperature control.

Operative management of bilateral Salter-Harris type III fractures of the proximal phalanges of the great toes of a 10-year-old female ballet dancer: a case report.

Differentiation between the normal variant cleft epiphysis and Salter-Harris type III fracture of the first proximal phalanges of the foot in children might be challenging. The authors describe a case of a 10-year-old ballet dancer girl with bilateral epiphyseal segmentation of the first proximal phalanges of the foot, unresponsive to conservative treatment. Considered a nonhealing stress-induced fracture, operative treatment with closed reduction and Herbert screw insertion was chosen on both sides. Complete union was achieved, with significant reduction of pain. The presented case suggests that internal fixation can be a viable option in the treatment of the problem.

Intraosseous generation of heat during guided surgical drilling: an ex vivo study of the effect of the temperature of the irrigating fluid

We measured the rise in the intraosseous temperature caused by freehand drilling or drilling through a surgical guide, by comparing different temperatures of irrigation fluid (10°C, 15°C, and 20°C), for every step of the drilling sequence (diameters 2.0, 2.5, 3.0, and 3.5mm) and using a constant drilling speed of 1200rpm. The axial load was controlled at 2.0kg. Bovine ribs were used as test models. In the guided group we used 3-dimensional printed surgical guides and temperature was measured with a thermocouple. The significance of differences was assessed with the Kruskal-Wallis analysis of variance. Guided drilling with 10°C irrigation yielded a significantly lower increment in temperature than the 20°C-guided group. When compared with the 20°C freehand group, the reduction in temperature in the 10°C guided group was significantly more pronounced at all diameters except 3.5mm. Finally, when the 10°C-guided group was compared with the 15°C groups, the temperature rise was significantly less at 2.5 and 3.0mm than with the guided technique, and at 3.0mm compared with the freehand technique. We suggest that the use of 10°C pre-cooled irrigation fluid is superior to warmer fluid for keeping temperature down, and this reduces the difference between guided and freehand drilling.