Douglas P. Beall

The Function of the Hip Capsular Ligaments: A Quantitative Report

PURPOSE Our purpose was to analyze the anatomy and quantitative contributions of the hip capsular ligaments. METHODS The stabilizing roles of the medial and lateral arms of the iliofemoral ligament, pubofemoral ligament, and ischiofemoral ligament were examined in 12 matched pairs of fresh-frozen cadaveric hips (6 male and 6 female hips). The motion at the hip joint was measured in internal and external rotation through ranges of motion from 30 degrees flexion to 10 degrees extension along a neutral swing path. The motion was standardized by use of frame stabilization and motion tracking. RESULTS There is a clear and consistent ligamentous pattern within the hip corresponding to a distinct function and contribution to internal and external rotation. On releasing the ischiofemoral ligament, the greatest gain in range of motion was that of internal rotation. The largest increase of motion by releasing the pubofemoral ligament was observed in external rotation, especially during extension. The release of the medial and lateral arms of the iliofemoral ligament each gave the greatest increase of motion in external rotation, with the lateral arm release providing more range of motion in flexion and in a neutral position. The lateral arm release also showed a significant motion increase in internal rotation, primarily in extension. CONCLUSIONS The ischiofemoral ligament controls internal rotation in flexion and extension. The lateral arm of the iliofemoral ligament has dual control of external rotation in flexion and both internal and external rotation in extension. The pubofemoral ligament controls external rotation in extension with contributions from the medial and lateral arms of the iliofemoral ligament. Together, these findings can have significant clinical applications. CLINICAL RELEVANCE When abnormal muscular and osseous pathology can be eliminated as a cause of instability or restrictive range of motion, the understanding of the independent functions of the hip ligaments will aid in defining accurate assessment and nonsurgical and arthroscopic treatment techniques.

Atlanto-occipital dislocation with traumatic pseudomeningocele formation and post-traumatic syringomyelia.

Study Design. A case report of traumatic atlanto-occipital dislocation complicated by the development of anterior and posterolateral pseudomeningoceles and the late development of syringohydromyelia is presented. Objective. To describe a unique post-traumatic and postsurgical course following atlanto-occipital dislocation. Summary of Background Data. Syringomyelia is a significant potential long-term complication in patients recovering from traumatic atlanto-occipital dislocation. Cord enlargement and increased T2 signal can be a marker of abnormal cerebrospinal fluid flow dynamics. This “presyrinx state” can be seen before clinical evidence of neurologic compromise. Pseudomeningocele formation after atlanto-occipital dislocation is rare, with only 3 reported cases. To our knowledge, all reported cases describe retropharyngeal pseudomeningoceles, and posterolateral pseudomeningocele as seen in this case has not previously been described. Methods. A single case is reported with an emphasis on the imaging findings related to the patient’s subsequent neurologic deterioration. Results. Following a pedestrian-motor vehicle collision, the patient received initial evaluation and treatment at a local foreign medical facility, where his cervical spine was cleared. Several days following stabilizing treatment and surgery, the patient was transferred to a foreign-based United States military medical facility and ultimately to our institution, where magnetic resonance imaging demonstrated occipitocervical dissociation. The patient was taken to the operating room for surgical stabilization. Four months after his index operation, the patient underwent halo removal. Follow-up magnetic resonance imaging revealed thickening of the cervical spinal cord in conjunction with diffuse high cord T2 signal and a small low cervical segment of syringomyelia. The patient was observed with follow-up magnetic resonance imaging obtained after 1 month. At this time, the low cervical syrinx had enlarged slightly, a small thoracic syrinx was observed, and cine imaging of cerebrospinal fluid flow demonstrated obstruction at the level of the foramen magnum. The patient was taken to the operating room fordecompression of the foramen magnum and posterior fossa and duraplasty. One month later, the patient’s clinical condition began to deteriorate, and repeat imaging showed continued enlargement of the patient’s syrinx and hydrocephalus. He was admitted for an urgent shunt procedure but unfortunately sustained cardiorespiratory arrest while on the ward awaiting surgery. Conclusions. Atlanto-occipital dislocation is rarely survivable, and delayed diagnosis can negatively affect long-term clinical outcome. This case illustrates how, despite early signs of improvement, post-traumatic syringomyelia may occur months or even years after spinal trauma and should always be considered in patients who experience late neurologic deterioration after atlanto-occipital dislocation.

Speech recognition interface to a hospital information system using a self-designed visual basic program: Initial experience

Speech recognition (SR) in the radiology department setting is viewed as a method of decreasing overhead expenses by reducing or eliminating transcription services and improving care by reducing report turnaround times incurred by transcription backlogs. The purpose of this study was to show the ability to integrate off-the-shelf speech recognition software into a Hospital Information System in 3 types of military medical facilities using the Windows programming language Visual Basic 6.0 (Microsoft, Redmond, WA). Report turnaround times and costs were calculated for a medium-sized medical teaching facility, a medium-sized nonteaching facility, and a medical clinic. Results of speech recognition versus contract transcription services were assessed between July and December, 2000. In the teaching facility, 2,042 reports were dictated on 2 computers equipped with the speech recognition program, saving a total of US

Image compression and chest radiograph interpretation: Image perception comparison between uncompressed chest radiographs and chest radiographs stored using 10∶1 JPEG compression

3,319 in transcription costs. Turnaround times were calculated for 4 first-year radiology residents in 4 imaging categories. Despite requiring 2 separate electronic signatures, we achieved an average reduction in turnaround time from 15.7 hours to 4.7 hours. In the nonteaching facility, 26,600 reports were dictated with average turnaround time improving from 89 hours for transcription to 19 hours for speech recognition saving US

Mri diagnosis of occult ganglion compression of the posterior interosseous nerve and associated supinator muscle pathology

45,500 over the same 6 months. The medical clinic generated 5,109 reports for a cost savings of US

Anatomic and structural evaluation of the hip: a cross-sectional imaging technique combining anatomic and biomechanical evaluations.

10,650. Total cost to implement this speech recognition was approximately US

Magnetic Resonance Imaging Findings of Golf-Related Injuries

3,000 per workstation, mostly for hardware. It is possible to design and implement an affordable speech recognition system without a large-scale expensive commercial solution.

Percutaneous augmentation of the superior pubic ramus with polymethyl methacrylate : treatment of acute traumatic and chronic insufficiency fractures

We have assessed the effect of 10∶1 lossy (JPEG) compression on six board-certified radiologists’ ability to detect three commonly seen abnormalities on chest radiographs. The study radiographs included 150 chest radiographs with one of four diagnoses: normal (n=101), pulmonary nodule (n=19), interstitial lung disease (n=19), and pneumothorax (n=11). Before compression, these images were printed on laser film and interpreted in a blinded fashion by six radiologists. Following an 8-week interval, the images were reinterpreted on an image display workstation after undergoing 10∶1 lossy compression. The results for the compressed images were compared with those of the uncompressed images using receiver operating characteristic (ROC) analyses. For five of six readers, the diagnostic accuracy was higher for the uncompressed images than for the compressed images, but the difference was not significant (P>.1111). Combined readings for the uncompressed images were also more accurate when compared with the compressed images, but this difference was also not significant (P=.1430). The sensitivity, specificity, and accuracy values were 81.5%, 89.2%, and 86.7% for the compressed images, respectively, as compared with 78.9%, 94.5%, and 89.3% for the uncompressed images. There was no correlation between the readers’ accuracy and their experience with soft-copy interpretation; the extent of radiographic interpretation experience had no correlation with overall interpretation accuracy. In conclusion, five of six radiologists had a higher diagnostic accuracy when interpreting uncompressed chest radiographs versus the same images modified by 10∶1 lossy compression, but this difference was not statistically significant.

Pubic symphyseal width in pediatric patients

Occult interosseous ganglions in the proximal forearm can result in pain and decreased supination. We will describe the magnetic resonance imaging (MRI) diagnosis of an interesting case of supinator atrophy secondary to compression of the posterior interosseous branch of the radial nerve. A brief review of this entity follows.

Intervertebral disk cyst: a case report.

To describe a technique of cross-sectional imaging of the adult hip designed to evaluate for anatomic anomalies that may predispose to internal derangement in addition to the routine anatomic assessment. Magnetic resonance (MR) imaging, MR arthrography, and multidetector computed tomography (MDCT) scanning protocols utilize high-resolution imaging, and the surrounding anatomy is also assessed using these scanning techniques. Various measurements may be obtained to assess the overarching anatomic configuration including the caput caput collum diaphysis angle, the femoral angle of torsion, the acetabular angle of torsion, the center edge angle, and the femur length.