MR imaging of the tarsometatarsal joint: analysis of injuries in 11 patients

OBJECTIVE

We evaluated how well MR imaging revealed ligamentous and bony abnormalities in patients with injuries of Lisfranc's joint.

SUBJECTS AND METHODS

We evaluated the studies of 11 patients with plantar hyperflexion injuries of the foot who underwent MR imaging in all three planes using spinecho T1-weighted, fast spin-echo T2-weighted, and short inversion time inversion recovery sequences. In four of the 11 patients, a three-dimensional spoiled gradient-recalled acquisition in the steady-state volume sequence was performed in the coronal plane. For five of the 11 patients, radiographs were available for evaluation.

RESULTS

Radiographs revealed tarsometatarsal joint malalignment in all five patients for whom plain films were available, metatarsal fractures in four of these patients, and tarsal fractures in the same four patients. MR imaging showed joint malalignment in all 11 patients and disruption of the Lisfranc's ligament in eight of the 11 patients. In the remaining three patients, normal Lisfranc's ligaments were associated with avulsion fractures of the second metatarsal bases or the medial cuneiform bones. On MR imaging, fractures of the metatarsal bases were evident in 10 of 11 patients. Fractures of the tarsal bones were seen in the same 10 patients.

CONCLUSION

MR imaging allows the detection of disruption of the Lisfranc's ligament as well as tarsal and metatarsal fractures and therefore may be a valuable technique in assessing patients after trauma to the tarsometatarsal joints when results of routine radiographs are not conclusive.

The role of employee flexible spending accounts in health care financing

Employee flexible spending accounts for health care represent one component of the current health care financing system that merits serious reform. These accounts create a system of undesirable incentives, force employees and employers to take complicated gambles, reduce tax revenues, and fail to meet their purported policy objectives. This paper describes shortcomings in these accounts from both a theoretical and an empirical perspective. Some proposed alternatives; including medical spending accounts and zero balance accounts, resolve many of these concerns but not all of them.

How much does inferior capsular shift reduce shoulder volume?

The purpose of this study was to quantitate the effect of inferior capsular shift on shoulder volume. Four fresh frozen cadaveric shoulders were analyzed. Volume before and after shift was determined using 3 techniques: (1) Magnetic resonance imaging sequences were digitized to computer and analyzed for volume via a 35-mm camera using Cue 2 software. The capsule was delineated by contrast between light and dark regions. Volume was calculated by summing the total area of respective slices. (2) Ultrasound images, obtained after surgical exposure of the capsule, were digitized. Volume was calculated using the formula for a prolate ellipsoid. (3) An 18-gauge needle was used to inject and evacuate saline via an anterior approach. Quantity of aspirated fluid provided a direct measure of volume. Inferior capsular shift was performed. After the operation, measurements were repeated. Inferior capsular shift reduced volume in all shoulders with each technique. On average, inferior capsular shift reduced joint volume by 57 %). A measurable reduction in shoulder joint volume is an effect of capsular shift. This measurement may have clinical application if volume is an indicator of instability or laxity.

Individual choice in spending accounts. Can we rely on employees to choose well?

Flexible spending accounts (FSA) represent a current health care financing tool that may become an important component of incremental health care reform. Because FSAs require employees to make financial contributions based on anticipated health care needs, contribution decisions are likely to be subject to many of the errors made in other insurance decisions. The authors analyzed the benefits selections, benefits forms completion, and FSA contribution levels of approximately 9,500 employees of the University of Pennsylvania from 1987 to 1992. Default and repeat choice trends characterize the completion of benefits forms and the reselection of health insurance options by employees. Despite the economic benefits of contributing to an FSA, only 14% of employees contributed in any one year and 73% never made a contribution. Multivariate models of these contributions fail to demonstrate the importance of what ought to be relevant influences in contribution decisions (for example, age, income, family status, or underlying health insurance). Whereas most FSA decisions are characterized by default contributions of $0, employees who contribute in one year are most likely to contribute exactly the same amount the next year, even when other circumstances change. The pervasiveness of these patterns raises concerns that health care reform plans that rely on financial incentives at the consumer level--for example, proposed medical saving accounts--will be inefficient.

MRI features in de Quervain's tenosynovitis of the wrist

De Quervain's stenosing tenosynovitis of the first dorsal extensor component is traditionally diagnosed clinically but may be encountered when performing MRI of the wrist. A retrospective review of wrist MR images was performed in cases where the diagnosis of de Quervain's synovitis was suggested (n = 5). Imaging findings were correlated with clinical findings in four cases and with wrist arthroscopy in one case. Increased thickness of the extensor pollicus brevis and abductor pollicis longus tendons was the most reliable finding on MRI, being present in all cases. Peritendinous edema was also a reliable finding. Surrounding subcutaneous edema and increased intratendinous signal were less reliable findings in confirmed cases of de Quervain's disease. De Quervain's tenosynovitis may be encountered when performing MRI of the wrist. Increased tendon thickness and peritendinous edema are the most reliable imaging findings.

Timing payments to subjects of mail surveys: cost-effectiveness and bias

Although mailed surveys are an important component of epidemiological research, results from mailed surveys are often suspect because of poor response rates and the potential for nonresponse bias. Previous work has demonstrated that paying subjects to complete questionnaires increases response rates, but this work has not well addressed the impact of the timing of incentives on total cost, cost effectiveness, and response bias. We surveyed 400 university employees about health benefits. By random allocation, half received a check for $5 along with the mailed survey, and the other half received the promise of $5 on return of a completed survey. The response rates for both groups were about the same (64 and 59%, respectively), but prepayment was less expensive in aggregate and less expensive per response. In addition, we found that subjects with lower salaries were more likely to respond when paid in advance. We conclude that prepayment may actually be less expensive and more cost effective than payment on completion, but that the timing of payment may influence the profile of respondents.

Complete dislocation of the knee: spectrum of associated soft-tissue injuries depicted by MR imaging

OBJECTIVE

Complete knee dislocation is a rare injury. The purpose of this study was to evaluate the spectrum of injuries that are depicted by MR imaging in patients with a dislocation of the knee and to determine if there is any predictive factor that might indicate those patients who may be at risk for popliteal nerve injury.

MATERIALS AND METHODS

A retrospective search for patients sustaining traumatic knee dislocations who had radiographs and an MR imaging examination of the knee as part of their initial evaluation was done at three level I trauma centers for the period between 1989 and 1993. Each MR examination was independently reviewed by three osteoradiologists for ligamentous, tendinous, meniscal, and osseous injuries. Equivocal diagnoses were decided by consensus. Only patients who underwent surgery were selected. MR imaging findings were confirmed at the time of surgery. Seventeen patients (15 men, two women; age range, 14-62 years; mean age, 29 years) were studied. Motor vehicle accident, fall from a height, a vehicle striking a pedestrian, and football injury were common mechanisms of injury. Posterior dislocation (seven patients) and anterior dislocation (five patients) were the most common injuries.

RESULTS

At the time of surgery, all patients had complete tears of the anterior cruciate ligament, 15 had complete tears of the posterior cruciate ligament, nine had complete tears of the medial collateral ligament, and 12 had tears of the fibular collateral ligament (nine tore both the fibular collateral ligament and the biceps femoris tendon). Popliteal tendon tears occurred in eight patients (six complete, two partial). Of the six patients with complete tears of the popliteal tendon, five occurred at the musculotendinous junction; all were the result of either posterior or posterolateral dislocations. Four patients had injuries to the peroneal nerve; three of the four also had tears of the popliteal tendon. On MR imaging, the integrity of the anterior cruciate and lateral collateral ligaments was correctly depicted in all 17 patients; evaluation of the posterior cruciate ligament resulted in one false-positive and one false-negative diagnosis of a tear; evaluation of the medial collateral ligament resulted in one false-positive diagnosis of a tear; and one false-positive diagnosis of a tear occurred with evaluation of the popliteal tendon.

CONCLUSION

Knee dislocations cause extensive disruption of the ligaments that stabilize the knee and the surrounding soft-tissue structures, including the popliteal artery. Nearly all will result in disruption of the cruciate ligments and, often, injury of the collateral ligaments. An injury to the popliteal tendon denotes a more severe injury. The mechanism of injury that results in a popliteal tendon tear may also increase the possibility of a peroneal nerve injury. Recognition of this pattern of injuries on MR imaging enables precautionary observation for ischemic changes of the foot to be instituted in patients that otherwise may not be considered at risk for acute vascular compromise.

The MR appearance of cruciate ganglion cysts: a report of 16 cases

Intra-articular ganglion cysts arising from the cruciate ligaments are unusual lesions, there being only nine previously reported cases. We report 16 cases and describe their MR appearance. Nine ganglia originated from the posterior cruciate ligament, most often appearing as well-defined multilocular lesions. The seven ganglia arising from the anterior cruciate ligament most often appeared as fusiform cystic lesions extending along and interspersed within the fibers of the ligament. Although uncommon, intra-articular ganglion cysts arising from the knee appear to have a distinctive MR appearance which should allow their correct diagnosis.

Inhibin as a marker for hydatidiform mole: a comparative study with the determinations of intact human chorionic gonadotrophin and its free beta-subunit

OBJECTIVE

The purpose of the study was to evaluate plasma inhibin as a marker of hydatidiform mole and to compare the results with intact human chorionic gonadotrophin (hCG) and its free beta-subunit.

DESIGN

Serial determinations of the plasma concentrations of inhibin, intact human chorionic gonadotrophin and its free beta-subunit in cases of hydatidiform mole over an average period of 140 days.

PATIENTS

Five cases of hydatidiform mole, including patients with spontaneous remission after evacuation or persistent trophoblastic disease.

MEASUREMENTS

Immunoreactive inhibin, hCG and free hCG beta-subunit were measured using standard enzyme immunoassays.

RESULTS

Inhibin and free hCG beta-subunit levels were greater than in normal pregnant women at the same gestational age. Only intact hCG could detect the persistence of trophoblastic tissue.

CONCLUSIONS

Our data suggest that inhibin, intact human chorionic gonadotrophin and free beta-subunit might be useful as diagnostic markers of molar pregnancies. However, the original method of intact hCG determination is still superior for follow-up.

Inhibition of P-glycoprotein-mediated vinblastine transport across HCT-8 intestinal carcinoma monolayers by verapamil, cyclosporine A and SDZ PSC 833 in dependence on extracellular pH

The ability of the multidrug resistance modifiers R- and R,S-verapamil (VPL), cyclosporine A (CsA) and its non-immunosuppressive derivative SDZ PSC 833 (PSC 833) to inhibit P-glycoprotein (P-gp)-mediated transepithelial flux of tritiated vinblastine was investigated using tight and highly resistant (R > 1,400 omega cm2) monolayer cultures of intestinal adenocarcinoma-derived HCT-8 cells grown on permeable tissue-culture inserts. Apical addition of these chemosensitizers inhibited drug flux (137 pmol h-1 cm-2; range, 133-142 pmol h-1 cm-2) in the basal to apical secretory direction at clinically relevant concentrations, with PSC 833 showing the highest activity, exhibiting inhibition at concentrations as low as 10 ng/ml (9 nM). Acidification of the modulator-containing apical compartment to an extracellular pH (pHo) of 6.8 had no influence on MDR reversal by CsA at 1 microgram/ml (0.9 microM; flux inhibition, 52%) or by PSC 833 at 100 ng/ml (0.09 microM; flux inhibition, 60%), in contrast to R,S- and R-VPL, which showed decreased inhibition and caused less accumulation of vinblastine in HCT-8 cells under this condition (flux inhibition of 35% and 23%, respectively, at pHo 6.8 vs 50% and 43%, respectively, at pHo 7.5). P-gp-mediated rhodamine 123 efflux from dye-loaded single-cell suspensions of HCT-8 cells as measured by flow cytometry was not impeded at pHo 6.8 in comparison with pHo 7.5 in standard medium, but at low pHo the inhibitory activity of R-VPL (29% vs 60% rhodamine 123 efflux inhibition) was diminished significantly, again without a reduction in the effect of PSC 833 (rhodamine 123 flux inhibition, 75%). In conclusion, drug extrusion across polarised monolayers, which offer a relevant model for normal epithelia and tumour border areas, is inhibited by the apical presence of R,S- and R-VPL, CsA and PSC 833 at similar concentrations described for single-cell suspensions, resulting in increased (2.2- to 3.7-fold) intracellular drug accumulation. Functional apical P-gp expression, the absence of paracellular leakage and modulator-sensitive rhodamine 123 efflux in single HCT-8 cells indicate a P-gp-mediated transcellular efflux in HCT-8 monolayers. In addition to its high MDR-reversing capacity, the inhibitory activity of PSC 833 is not affected by acidic extracellular conditions, which reduce the VPL-induced drug retention significantly. As far as MDR contributes to the overall cellular drug resistance of solid tumours with hypoxic and acidic microenvironments, PSC 833 holds the greatest promise for clinical reversal of unresponsiveness to the respective group of chemotherapeutics.

MR appearance of idiopathic synovial osteochondromatosis

OBJECTIVE

A retrospective review of the MR examinations in 21 patients with idiopathic synovial osteochondromatosis (ISO) was performed to determine its MRI characteristics.

MATERIALS AND METHODS

Twenty-one patients diagnosed with ISO had undergone MRI prior to surgery. The MR images were retrospectively evaluated for configuration and extent of lesion as well as for signal characteristics.

RESULTS

Three distinct MR patterns were seen in ISO: A--lobulated homogeneous intraarticular signal isointense to slightly hyperintense to muscle on T1-weighted images and hyperintense on T2-weighted images (n = 3); B--pattern A plus foci of signal void on all pulse sequences (n = 17); and C--features of pattern A and B plus foci of peripheral low signal surrounding central fat-like signal (n = 2). The foci of signal void in pattern B and C corresponded to areas of calcification and the foci of peripheral low signal surrounding central fat-like signal in pattern C corresponded to areas of ossification.

CONCLUSION

The MR appearance of ISO appears sufficiently unique to allow its differentiation from other causes of intraarticular pathology.

Relationship between 90-kilodalton heat shock protein, estrogen receptor, and progesterone receptor in human mammary tumors

To determine, if, as previously observed with rodent uterus, the 90 kilodalton heat shock protein (HSP-90) might be under estrogenic regulation in human mammary tumors, we analyzed its relationship with estrogen and progesterone receptors. A positive relationship between estrogen receptor and HSP-90 was observed when these were normalized to HSP-70 levels (to normalize for the intrinsic variations in each tumor, independent of any hormonal dependence).

The mushroom femoral head. A radiographic investigation

RATIONALE AND OBJECTIVES

In 1913, anthropologist Ales Hrdlicka described a number of femora as having "mushroom heads," a deformity he attributed to arthritis deformans. The authors have attempted to define the cause of this condition.

METHODS

Forty of 41 femora with "mushroom" femoral heads collected by Hrdlicka were grossly inspected and examined with plain radiographs and with computed tomography. Femoral neck angulation and degree of anteversion were determined.

RESULTS

Three distinct categories were established: group I, those specimens with normal angulation and short femoral necks; group II, those with varus angulation and short femoral necks; and group III, those with normal-sized femoral necks and normal femoral neck angulation. No correlation was found between degree of anteversion and the categories. Additionally, most of the mushroom deformities were related to osteophyte formation.

CONCLUSIONS

Most of the changes in the femora were the result of osteoarthritis. Two groups showed evidence of growth disturbances that occurred early in life. The changes in the second group were similar to those seen in Legg-Calvé-Perthes disease.

Visual field defects in vascular lesions of the lateral geniculate body

Corresponding retinal nerve fibres begin their path in the eyes and end in a single visual cortical cell. Because of this arrangement, lesions in the anterior visual pathway produce incongruent visual field defects and in the posterior pathway congruent field defects. The lateral geniculate body is on the anterior third of the visual pathway. A lesion of this nucleus produces moderately to completely congruent visual field defects. Five patients with ischaemic lesions of the lateral geniculate body are reported. Two patients had a wedge-shaped homonymous hemianopia, two other cases had congruent superior homonymous quadratic defects and the fifth a quadruple sector defect. The lateral geniculate body has a dual blood supply from the anterior choroidal artery (branch from internal carotid artery) and from the lateral choroidal artery (branch from the posterior cerebral artery). A schematic diagram has been devised which shows that a knowledge of the visual field disrupted can identify the arterial system involved.

[Auditory evoked potentials in Fisher's syndrome. A clinical case]

A 15 year old patient developed ataxia 2 weeks after an upper respiratory infection. Absent reflexes, external ophthalmoplegia, bilateral ptosis, isochoric mydriasis and week photomotor reflexes (Bell's phenomenon) were noted. A slight increase in protein but not cell content of the CSF was observed. Miller-Fisher syndrome was diagnosed on clinical grounds and visual and auditory evoked potentials were explored and found to be normal. This is in complete agreement to the literature and indicates indemnity of the central nervous system in Miller-Fisher's syndrome. Peripheral nervous system abnormalities that have been identified by pathologic and radiologic studies may explain all of the alterations observed in this syndrome.

Androgen receptor defects in patients with minimal and partial androgen resistance classified according to a model of androgen-receptor complex energy states

We have characterized intracellularly the androgen-receptor (A-R) complexes formed by genital skin fibroblasts from 2 unrelated males with qualitative defects of the androgen receptor: one has a small nonhypospadic penis as part of a syndrome of mild androgen resistance; the other was born with ambiguous external genitalia. The dissociation rate constants of testosterone, methyltrienolone (MT), dihydrotestosterone (DHT) and mibolerone (MB) from normal androgen receptors were determined at various temperatures: when plotted by the method of Arrhenius, they yielded a linear hierarchy of dissociation states with energies of state IV greater than III greater than II greater than I, respectively. Relative to this hierarchy, patient A-R complexes were displaced to higher, androgen-inappropriate energies in a mutant-distinctive pattern. MB- or MT-R complexes of both patients were thermolabile; however, both up-regulated normally in response to prolonged incubation with either hormone. Apparent equilibrium affinity constants (Kd) of the DHT- and MB-R complexes formed by both patients were normal; however, the binding capacity (Bmax) for MB in 1 case was subnormal. The distinctive biochemical phenotypes of A-R complexes in these 2 patients with androgen resistance will facilitate the definition of structure-function relations in the androgen receptor, a classical DNA-binding, transcription-regulating protein.

[The wish for a baby and pregnancy in adolescence]

During the Summer of 1987, interviews were carried out with 33 pregnant adolescents followed at the Nancy regional maternity hospital, in order to improve the knowledge of the present determinants of pregnancy in teens. These adolescents were mostly French, born in unfavourable classes; virtually all had school failure and no professional qualification. In one third of them, pregnancy was accidental and could appear as a further social handicap for these isolated and unemployed adolescents. However, two thirds of these future mothers declared that they had desired their pregnancy, most often within a steady and gratifying couple relationship.