New imaging markers for preconceptional and first-trimester utero-placental vascularization.

INTRODUCTION: The availability of imaging makers of early placental circulation development is limited. This study aims to develop a feasible and reliable method to assess preconceptional and early first-trimester utero-placental vascular volumes using three-dimensional power Doppler (3D PD) ultrasound on two different Virtual Reality (VR) systems. METHODS: 3D PD ultrasound images of the uterine and placental vasculature were obtained in 35 women, either preconceptionally (n = 5), or during pregnancy at 7 (n = 10), 9 (n = 10) or 11 (n = 10) weeks of gestation. Preconceptional uterine vascular volume (UVV), first-trimester placental vascular volume (PVV) and embryonic vascular volume (EVV) were measured by two observers on two VR systems, i.e., a Barco I-Space and VR desktop. Intra- and inter-observer agreement and intersystem agreement were assessed by intra-class correlation coefficients (ICC) and absolute and relative differences. RESULTS: Uterine-, embryonic- and placental vascular volume measurements showed good to excellent intra- and inter-observer agreement and inter-system reproducibility with most ICC above 0.80 and relative differences of less than 20% preconceptionally and almost throughout the entire gestational age range. Inter-observer agreement of PVV at 11 weeks gestation was suboptimal (ICC 0.69, relative difference 50.1%). DISCUSSION: Preconceptional and first-trimester 3D PD ultrasound utero-placental and embryonic vascular volume measurements using VR are feasible and reliable. Longitudinal cohort studies with repeated measurements are needed to further validate this and assess their value as new imaging markers for placental vascular development and ultimately for the prediction of placenta-related pregnancy complications.

Effect of pretension in reconstructions of the anterior cruciate ligament with a Dacron prosthesis. A retrospective study.

To study the effect of the pretension level in reconstructions of the anterior cruciate ligament (ACL) we examined 26 patients with isolated ACL insufficiency and intact Dacron ligament prosthesis at 4-year follow-up. The patients were divided into two groups of 13 each, based on pretension level applied at the reconstruction: in group I the ligament was pretensioned to 60 N and in group II to 40 N. The patients were evaluated by the Tegner and Lysholm scores, KT-1000 arthrometer measurements, and isokinetic muscle performance testing and were assessed by the Knee Ligament Standard Evaluation Form of the International Knee Documentation Committee. At follow-up there were no differences between the two groups in any of the evaluated parameters except for squatting ability. The two groups differed significantly (P < 0.01) with regard to the squatting score: 11 patients in group I had decreased squatting ability, and 6 of these were not able to squat beyond 90 degrees of flexion. In contrast, only 4 patients in group II had slightly impaired squatting ability. It is likely that this difference between the two groups is related to the magnitude of the pretension applied to the ligament prosthesis, and that the pretension exerts its influence through a change in the knee kinematics introduced at the time of the reconstruction.