The additive use of an external modular device may improve dorsal compression forces in pelvic external fixation. This would improve the efficiency of indirect reduction and stabilization with an anterior pelvic external fixator. The purpose of this study was to determine the forces of the posterior pelvis achieved by a new device improving the application of a supraacetabular anterior external fixator compared with other constructs. Synthetic pelvic models were used. Complete pelvic ring instability was created by symphyseal and unilateral sacroiliac joint disruption. Four different constructs of fixation were tested. A pressure-sensitive film was placed in the sacroiliac joint. The constructs were applied in a standardized way. The maximum sacroiliacal compression loads (N) of each trial was recorded. Statistics was performed with the student t-test.Objectives
Material and Method
Overlooked compartment syndrome represents a devastating complication for the patient. Invasive compartment pressure measurement continues to be the gold standard. However, repeated measurements in uncertain cases may be difficult to achieve. We developed a new, noninvasive method to assess tissue firmness by pressure related ultrasound. Decreased tissue elasticity by means of rising compartment pressures was mimicked by infusion of saline directly into the anterior tibial compartment of 6 human specimens post mortem. A pressure transducer (Codman) monitored the pressure of the anterior tibial compartment. A second transducer was located in a saline filled ultrasound probe head to allow a simultaneous recording of the probe pressure provoked by the user. The ultrasound images were generated at 5 and 100mmHg probe pressures to detect the tissue deformity by B-mode ultrasound. The fascial displacement was measured before and after compression (d). Subsequently, increments of 5mmHg pressure increases were used to generate a standard curve (0–80mmHg), thus mimicking rising compartment pressures. The intra-observer reliability was tested using 10 subsequent measurements. A correlation was determined between d and the simulated intacompartmental pressure (ICP) in the compartment. The Pearson correlation coefficient (r) was calculated. The reliability determined by the kappa value and a regression analysis was performed.Background
Methods
An MR scan was performed on all patients who presented to our hospital with a clinical diagnosis of a fracture of the proximal femur, but who had no abnormality on plain radiographs. This was a prospective study of 102 consecutive patients over a ten-year period. There were 98 patients who fulfilled our inclusion criteria, of whom 75 were scanned within 48 hours of admission, with an overall mean time between admission and scanning of 2.4 days (0 to 10). A total of 81 patients (83%) had abnormalities detected on MRI; 23 (23%) required operative management. The use of MRI led to the early diagnosis and treatment of occult hip pathology. We recommend that incomplete intertrochanteric fractures are managed non-operatively with protected weight-bearing. The study illustrates the high incidence of fractures which are not apparent on plain radiographs, and shows that MRI is useful when diagnosing other pathology such as malignancy, which may not be apparent on plain films.
