Description of Standardized Planes and Angles for Percutaneous Supra-acetabular Screw Placement.

BACKGROUND: Percutaneous screw fixation for pelvic fractures has become a minimally invasive alternative to an open operation. The complex anatomy of the pelvis renders this procedure challenging. The objective of this study was to assess standardized angles and dimensions of safety zones within a 3 D computed tomography model for optimal supra-acetabular screw placement. METHODS: Computed tomography scans of 107 patients that suffered major trauma without showing any bone injury of the pelvis were collected. Using a software-based analysis, raw computed tomography data were transformed into 3 D models to set standardized landmarks and determine the possible insertion corridor. RESULTS: Screws not exceeding a length of 97 mm in females and 106.4 mm in males were, in 95% of the evaluated cases, insertable without cortical bone penetration. The safety zone was 6.6 mm for females and 7.9 mm for males. Screws not exceeding these diameters were safely insertable in 95% of the cases. For the midsagittal plane, the angle was 36.4 ± 5.1 on the left and 34.7 ± 2.9 on the right (p = 0.008). For the anterior pelvic plane, the angle was 31.3 ± 4.5° on the left and 34.0 ± 4.8° on the right (p = 0.008). CONCLUSIONS: Percutaneous fixation using supra-acetabular screws is a promising method to treat simple supra-acetabular fractures. These results may improve its safe utilization and could facilitate its broader clinical application.

Is Prematurity a Protective Factor Against Developmental Dysplasia of the Hip? A Retrospective Analysis of 660 Newborns.

PURPOSE: In Middle Europe developmental dysplasia of the hip (DDH) has an incidence of up to 5.9 %. The rate of congenital hip dislocation as the worst complication of a growth disorder of the hip is between 1.5 % and 2.5 %. Among known risk factors of DDH are breech position, multiples, foot deformities and family history. The aim of this retrospective study was to investigate prematurity as a risk factor for developmental dysplasia of the hip (DDH). MATERIALS AND METHODS: The hips of 283 infants who were born before the 38th week of gestation or earlier, and those of 377 infants who were born after the 37th week of gestation, none of whom had other risk factors for DDH, were compared using the ultrasound technique according to Graf et al., within the first week after birth. Both hips of all infants were included in the study. RESULTS: Surprisingly, the difference in alpha angles between the two groups was statistically extremely significant, favoring the preterm infants. Moreover, we found a physiological curve of alpha angle development with a peak after the 31st week of gestation. The incidence of pathological dysplasia was not significantly different in the two groups. CONCLUSION: Our results suggest that prematurity is not a predisposing factor for DDH, but rather is protective for hip development.

Comparison of the Subjective Elbow Value with the DASH, MEPS und Morrey Score after Olecranon Fractures. / Vergleich der subjektiven Ellenbogenfunktion mit dem DASH-Score, MEPS und Morrey-Score nach operativer Versorgung von Olekranonfrakturen.

BACKGROUND: Olecranon fractures are common injuries that can occur in patients of any age. To assess the postoperative outcome, multiple scoring systems like the DASH, MEPS und Morrey Score have been described. The goal of this paper is to compare the subjective elbow value (SEV) to these commonly used scoring systems. We hypothesized that the SEV would have a high correlation and practicability for the evaluation of elbow function after isolated olecranon injury. PATIENTS AND METHODS: Clinical data of 40 patients were collected and retrospectively analysed. All patients suffered an isolated olecranon fracture and were surgically treated by tension band wiring or plate fixation. In the follow-up examinations the Mayo Score, DASH Score, Morrey Score and SEV were measured for correlation purposes. RESULTS: The mean follow-up time was 70.5 ± 45.6 months. The median DASH Score was 9.9 (4.1 - 20.4) and 100 (85 - 100) for the MEPS. The median Morrey Score was 98 (92 - 100). The median SEV was 90% (80 - 95%). The Pearson correlation between the DASH and SEV was -0.85 and 0.80 between the MEPS and the SEV. CONCLUSIONS: The SEV shows a high correlation to the most commonly used scoring systems for outcome evaluation after elbow injury. It is easy to use and can be seen as a valuable tool to assess patients after olecranon fractures.

Outcome evaluation of new calcium titanate schanz-screws for external fixators. First clinical results and cadaver studies.

OBJECTIVE: External fixators are important for correcting length discrepancies and axis deformities in pediatric or trauma orthopedic surgery. Pin loosening is a common pitfall during therapy that can lead to pain, infection, and necessary revisions. This study aims to present clinical data using calcium titanate (CaTiO3) Schanz screws and to measure the fixation strength. PATIENTS AND METHODS: 22 titanate screws were used for external fixators in 4 pediatric patients. Therapy was initiated to lengthen or correct axial deformities after congenital abnormalities. The maximum tightening torque was measured during implantation, and the loosening torque was measured during explantation. In addition, screws of the same type were used in a cadaver study and compared with stainless steel and hydroxyapatite-coated screws. 12 screws of each type were inserted in four tibias, and the loosening and tightening torque was documented. RESULTS: The fixation index in the in vivo measurement showed a significant increase between screw insertion and extraction in three of the four patients. The pins were in situ for 91 to 150 days, and the torque increased significantly (P = 0.0004) from insertion to extraction. The cadaveric study showed lower extraction torques than insertion torques, as expected in this setting. The calculated fixation index was significantly higher in the CaTiO3 group than in the other groups (P = 0.0208 vs. HA and P < 0.0001 vs. steel) and in the HA group vs. plain steel group (P = 0.0448). CONCLUSION: The calcium titanate screws showed favorable fixation strength compared to HA and stainless steel screws and should be considered in long-term therapy of external fixation.

3-D Optics for Thoracoscopic Vertebral Body Replacement - Essential Technical Progress or Just Nice to Have? / Die dreidimensionale Optik für den thorakoskopischen ventralen Wirbelkörperersatz ­ notwendiger Fortschritt oder nur "nice to have"?

BACKGROUND: Three-dimensional (3-D) endoscopic optics use 2 cameras to simulate the different perspectives of the right and left eye, creating the illusion of spatial depth. Optimised orientation as well as improved hand-eye coordination compared to 2-D-optics could be proven in standardised test setups (black box) and in laparoscopic use. This retrospective study examines whether these results can also be applied to thoracoscopic vertebral body replacement at the thoracolumbar junction. HYPOTHESES: 1. Ventral vertebral body replacement using 3-D-thoracoscopy results in a shorter operation time than with 2-D-thoracoscopy. 2. Perioperative blood loss is less, due to better spatial orientation (faster haemostasis) and reduced tissue laceration. MATERIAL AND METHODS: 29 patients met the inclusion criteria of this retrospective study. Between 08 - 2012 and 08 - 2017, all of these received ventral thoracoscopic vertebral replacement at the thoracolumbar junction (Th11 to L2). Patients with additional anterior procedures (e.g. anterolateral plate) were excluded. Perioperative data such as blood loss, duration of surgery and length of hospital stay were analysed. Conventional 2-D-optics were used in n = 14 patients and 3-D-optics in 15 patients. Aesculap EinsteinVision® 2.0 was used as the 3-D-optics. Statistical significance was calculated using Student's t-test. RESULTS: The most common diagnosis was a L1 fracture (n = 18, 62%). Mean OR time was 24 minutes shorter in the 3-D group (149 ± 29, 107 - 198 min) than in the 2-D group (173 ± 39, 125 - 260 min), but this difference was not significant. Total perioperative blood loss in the 3-D group was significantly lower than in the 2-D group (**p = 0.043). Proportional intraoperative blood loss in the 3-D group was also lower (mean around 115 ml), but not significantly so. Significantly lower values were found for the delivery rate of the thoracic drainage in the 3-D group (248 vs. 560 ml, *p = 0.195). Inpatient stay with the 3-D group was on average 1.5 days (d) shorter (8.7 d for the 3-D group, 10.2 d for the 2-D group) but this difference was not significant (p = 0.27). CONCLUSION: Thoracoscopic-assisted vertebral body replacement at the thoracolumbar junction is a safe and reliable surgical procedure using conventional 2-D-optics or the new 3-D-optics. Both methods allow thoracoscopic vertebral body replacement in comparable operation times but in our study the 3-D group presented with significantly lower postoperative blood loss. Due to the small number of cases and because of the retrospective design, the present study is considered to be a pilot study only.