Knowledge of periacetabular anatomy is crucial for prosthetic cup placement in total hip arthroplasty and for screw placement in anterior fixation with acetabular fractures. It is known that degree of hip dysplasia correlates with medial bone stock and that medial bone stock shows a weak correlation to Lequesne’s acetabular index (AI). Aim of this study was to investigate a possible correlation between AI and the newly proposed medial safe zone. AI and the medial save zone were measured on 419 hips using a computed-tomography scan of the pelvis. AI was assessed on a 2D reconstructed anterior-posterior view of the pelvis using VOXAR™. Correlation was measured using the Pearson correlation coefficient. Mean AI was 4.2 degrees (SD 4.9 degrees). Mean medial safe zone was 8.1 mm (SD 1.9 mm). There was a significant correlation between AI and medial save space with a Pearson correlation coefficient r = 0.33 (p = .001). There is a weak correlation between AI and medial safe zone. AI should not be used to predict medial safe zone. Due to the weakness in correlation AI is not suited for predicting medial safe zone. However, a low or negative AI can be a warning sign for less medial safe zone, prompting surgeons to take care when reaming in THA or placing periacetabular screws.
Background . External fixation is useful in the primary treatment of pelvic ring injuries. The present study compared the biomechanical stability of five different configurations of an external pelvic ring fixation system. Methods . Five configurations of an anterior external pelvic ring fixation system were tested using a universal testing machine. One single connecting rod was used in group “SINGLE,” two parallel connecting rods in group “DOUBLE,” two and four rods, respectively, in a tent-like configuration in groups “SINGLE TENT” and “DOUBLE TENT,” and a rhomboid-like configuration in group “RHOMBOID.” Each specimen was subjected to a total of 2000 consecutive cyclic loadings at 1 Hz lateral compression/distraction (±50 N) and torque (±0.5 Nm) loading alternating every 200 cycles. Translational and rotational stiffness were determined at 100, 300, 500, 700, and 900 cycles. Results . The “SINGLE TENT” and “RHOMBOID” configurations already failed with a preloading of 50 N compression force. The “DOUBLE” configuration had around twice the translational stability compared with the “SINGLE” and “DOUBLE TENT” configurations. Rotational stiffness observed for the “DOUBLE” and “DOUBLE TENT” configurations was about 50% higher compared to the SINGLE configuration. Conclusion . Using two parallel connecting rods provides the highest translational and rotational stability.
Der 22-jahrige Student stellte sich neun Wochen nach initialem Trauma, bei welchem er sich eine zweitgradig offene Unterschenkelschaftfraktur rechts zugezogen hatte, zur Zweitmeinung vor.
KPC-50 is a KPC-3 variant identified from a Klebsiella pneumoniae clinical isolate recovered in Switzerland in 2019. Compared to KPC-3, KPC-50 shows (i) a three-amino-acid insertion (Glu-Ala-Val) between amino acids 276 and 277, (ii) an increased affinity to ceftazidime, (iii) a decreased sensitivity to avibactam, explaining the ceftazidime-avibactam resistance, and (iv) an association with a sharp reduction of its carbapenemase activity.
Pelvic incidence (PI) has been linked to several degenerative processes within the spinopelvic system. Acetabular retroversion is a recognised risk factor for osteoarthritis of the hip. We therefore hypothesised that these two factors might be part of a specific anatomical variant associated with degenerative changes. This study was performed to clarify this issue. The pelvic incidence was measured on 589 computertomographical data sets acquired between 2008 and 2010. For 220 patients a 2D rendering in an antero-posterior view of the CT data set was performed to evaluate the parameters of acetabular retroversion. Those included the prominence of the ischial spine sign (PRISS), the cross-over sign (COS) and the posterior wall sign (PWS). Between 477 and 478 hips were evaluated depending on the parameter of retroversion. The mean pelvic incidence was significantly lower in hips positive for the PRISS and the PWS. However, there were no significant differences between hips positive or negative for the COS. As hypothesised, the lower PI values in PWS and PRISS positive hips suggest a link between PI and retroversion of the acetabulum. Whether this is of any clinical relevance remains, however, unknown. Acetabular retroversion is linked to PI. In hips where the prominence of the ischial spine sign and/or the posterior wall sign was present, the mean pelvic incidence value was lower.
Pelvic binders (PB) have become an established first-line treatment for on scene use in suspected pelvic ring injuries. A sustained incidence of incorrect placements was reported, usually above the trochanteric region. We examined if malplacement is associated with worse clinical parameters related to resuscitation.Retrospective chart review, level 1 center over a 3-year period. Inclusion criteria: adult patients (18-69y/o), high-energy injury, presence of a pelvic binder on admission - patients without binders served as controls. Exclusions: geriatric patients (>70y/o), ground level falls. Malplacement of the binder was assessed and graded (grade 1:<5 cm above trochanter, grade 2:5-10 cm, grade 3 > 10 cm) from the initial computed tomography scan (3D reconstruction).Seventy-six patients were included. Males (72%), mean age 47years (range 18-91, SD 19.4). Mean Injury Severity Score was 22.3 points (range 1 -48, SD 10.4) and mean Glasgow Coma Score on arrival was 10.8 points (range 3-15, SD 5.3). Fifty-three percent presented with a pelvic ring injury (74% of them with a type B or C fracture). Mean PB distance from the trochanteric region was 56 mm (range 41-247 mm, SD 54.5). Fifty percent of PBs were moderately displaced, 21% showed severe misplacement (>100 mm). Physiological parameters were unchanged regardless of the accuracy of PB placement.Incorrect placement of pelvic binders persists despite widespread implementation of the device. In our series, displacement was always cranially and had no effect on preclinical fluids received or parameters of resuscitation on arrival.III.
