Undisplaced scaphoid waist fractures: is 4 weeks' immobilisation in a below-elbow cast sufficient if a week 4 CT scan suggests fracture union?

This prospective study investigated a cohort of 59 scaphoid waist fractures which were treated nonoperatively in a below-elbow plaster cast for 4 weeks and then underwent a Week 4 CT scan to assess displacement and progress to union. Forty-three were classed as undisplaced and 37 of these 43 were also classed as 'united'. All the 37 undisplaced and 'united' fractures united with up to 8 weeks' cast immobilisation, including 26 which were taken out of plaster at 4 weeks and mobilised. We conclude that scaphoid waist fractures which appear to be undisplaced and united on a week 4 CT scan will unite, and may not need to be immobilised in a plaster cast for more than 4 weeks. Such a treatment policy may reduce the period of disability and time off work associated with nonoperative treatment.

Partial union of acute scaphoid fractures

Sixty-six patients with acute scaphoid fractures were treated non-operatively in a below elbow plaster for 8 to 12 weeks and underwent CT scans along the longitudinal axis of the scaphoid at 12 to 18 weeks. These scans showed that 14 fractures had not united and that 30 had united throughout the whole cross-section of the scaphoid. The other 22 had partially united with bridging trabeculae in some areas of the cross-section. These 22 partial unions were graded as 0% to 24% union (0 cases), 25% to 49% union (5 cases), 50% to 74% union (7 cases), and 75% to 99% union (10 cases). The 12 patients who had less than 75% fracture union were followed-up further and nine underwent another CT scan at 23 to 40 weeks after the initial injury. These showed union across the whole of the cross-section of the fracture in seven cases and 75% to 99% union in the other two cases, who had full and painless wrist function. We conclude that partial union of the scaphoid is a common occurrence but, in most cases, it progresses to full union without the need for prolonged plaster immobilization.

Gadolinium enhanced MR assessment of proximal fragment vascularity in nonunions after scaphoid fracture: does it predict the outcome of reconstructive surgery?

This study investigated whether the outcome of bone graft and internal fixation surgery for nonunion of scaphoid fractures could be predicted by gadolinium-enhanced MR assessments of proximal fragment vascularity. Sixteen established scaphoid fracture nonunions underwent gadolinium-enhanced MR scanning before surgical treatment with bone grafting and internal fixation. No relationship was found between MR enhancement and the outcome of surgery. Union was achieved in eight of the 12 nonunions with more than 50% enhancement, and three of the four with less than 50% enhancement, of the proximal pole. Furthermore, union was achieved in both of the nonunions which had less than 25% enhancement of the proximal pole. We conclude that enhanced MR assessments of the vascularity of the proximal fragment of a scaphoid fracture nonunion do not accurately predict the outcome of reconstructive surgery.

Scaphoid blood flow and acute fracture healing. A dynamic MRI study with enhancement with gadolinium

We have investigated whether assessment of blood flow to the proximal scaphoid can be used to predict nonunion in acute fractures of the scaphoid. We studied 32 fractures of the scaphoid one to two weeks after injury, by dynamic fat-suppressed T1-weighted gradient-echo MRI after the intravenous administration of gadopentetate dimeglumine (0.1 mmol/kg body-weight). Steepest slope values (SSV) and percentage enhancement values (%E) were calculated for the distal and proximal fragments and poles. All the fractures were treated by immobilisation in a cast, and union was assessed by CT at 12 weeks. Nonunion occurred in four fractures (12%), and there was no statistically significant difference between the proximal fragment SSV and %E values for the fractures which united and those with nonunion. The difference between the proximal pole SSV and %E values for the union and nonunion groups reached statistical significance (p < 0.05), but with higher enhancement parameters for the nonunion group. Our results suggest that poor proximal vascularity is not an important determinant of union in fractures of the scaphoid.

Scaphoid blood flow and acute fracture healing

We have investigated whether assessment of blood flow to the proximal scaphoid can be used to predict nonunion in acute fractures of the scaphoid. We studied 32 fractures of the scaphoid one to two weeks after injury, by dynamic fat-suppressed T1-weighted gradient-echo MRI after the intravenous administration of gadopentetate dimeglumine (0.1 mmol/kg body-weight). Steepest slope values (SSV) and percentage enhancement values (%E) were calculated for the distal and proximal fragments and poles. All the fractures were treated by immobilisation in a cast, and union was assessed by CT at 12 weeks.

Nonunion occurred in four fractures (12%), and there was no statistically significant difference between the proximal fragment SSV and %E values for the fractures which united and those with nonunion. The difference between the proximal pole SSV and %E values for the union and nonunion groups reached statistical significance (p < 0.05), but with higher enhancement parameters for the nonunion group. Our results suggest that poor proximal vascularity is not an important determinant of union in fractures of the scaphoid.

Reduction of erythema in hairless guinea pigs after cutaneous sulfur mustard vapor exposure by pretreatment with niacinamide, promethazine and indomethacin

Erythema is the initial symptom that occurs after sulfur mustard (HD) cutaneous exposure. The time course of HD-induced erythema is similar to that observed after UV irradiation, which can be reduced by indomethacin. Sulfur mustard lethality is decreased by using promethazine, which is an antihistamine. Niacinamide can reduce microvesication after HD vapor exposure in hairless guinea pig (HGP) skin. The present study examines the effect of the combined administration of niacinamide, indomethacin and promethazine used alone or in all possible combinations on the degree of erythema and histopathologic skin damage after HD exposure in HGP. Niacinamide (750 mg kg-1, i.p.), promethazine (12.5 mg kg-1, i.m.) or indomethacin (4 mg kg-1, p.o.) used singly or in combination was given as a 30-min pretreatment before an 8-min HD vapor cup skin exposure. Using a combination pretreatment of niacinamide, promethazine and indomethacin, erythema was reduced at 4 (91%) and 6 (55%) h, but not 24 h after HD. The incidence of histopathological skin changes (microvesicles, follicular involvement, epidermal necrosis, intracellular edema and pustular epidermatitis) 24 h after HD was not reduced. This study indicates that HD-induced erythema may result from several different mechanisms, including inflammation, histamine release and DNA damage. It is suggested that two phases of inflammation may occur: an early phase sensitive to antihistamines and non-steroidal antiinflammatory drugs and a late phase of extensive cell damage that was not sensitive to these drug pretreatments.

Case report: lipoma arborescens of the sub-deltoid bursa

Lipoma arborescens is a rare synovial disorder which principally affects the knee joint. We describe an unusual case of lipoma arborescens arising within the sub-deltoid bursa in association with a rotator cuff tear. Pre-operative diagnosis was made by magnetic resonance imaging.

Case report: benign urachal neoplasm

Benign urachal neoplasms have been rarely reported. We describe a case of a large benign mesenchymal neoplasm (21 x 19 x 14 cm) arising from the urachus, with imaging by computed tomography and ultrasound.

Short-term recall for 'probably benign' mammographic lesions detected in a three yearly screening programme

The outcome of short-term recall for the follow-up of 131 screen detected 'probably benign' non-palpable mammographic lesions is presented. Patients were selected for short-term recall after attending a dedicated assessment clinic and underwent repeat ipsilateral mammography 1 year later. Interval progression in the mammographic appearance prompted excision biopsy, whereas no change led to discharge back to the normal screening protocol. Of 35,671 asymptomatic women screened between 1988 and 1992, 1762 (5%) attended an assessment clinic. Subsequently, 131 women (7% assessed, 0.4% screened) were placed on short-term recall and were reviewed between 1989 and 1993 (age range 50-67 years). The 'probably benign' lesions were: calcifications (91 cases, 69%); circumscribed density (18 cases, 14%); parenchymal deformity/stellate density (13 cases, 10%); and asymmetric breast tissue (9 cases, 7%). 128/131 women attended for short-term recall (compliance 98%). Five from 128 were subject to excision biopsy with a yield of three invasive carcinomas and two ductal carcinomas in-situ. The positive predictive values for malignancy were: overall 'probably benign' lesions (PPV 3.9%); calcifications (PPV 3.3%); circumscribed density (PPV 0%); parenchymal deformity/stellate density (PPV 15.4%); and asymmetric breast tissue (PPV 0%). The largest carcinoma measured 15 mm and none of the tumours demonstrated vascular invasion or axillary metastases placing them in a favourable prognostic group. The results suggest that short-term recall is a reasonable management option for a small number of women with 'probably benign' calcifications. Parenchymal deformity and stellate densities should probably not be managed by this approach and require excision after initial assessment. Circumscribed densities and asymmetric breast tissue can be safely discharged following assessment.

Case report: chronic recurrent multifocal osteomyelitis with magnetic resonance imaging

A case of chronic recurrent multifocal osteomyelitis (CRMO) with spinal involvement is described. Diagnosis and monitoring of the disease process was considerably aided by magnetic resonance (MR) imaging. The MR appearances in chronic recurrent multifocal osteomyelitis have been rarely reported.

Pathogenesis of 2,2'-dichlorodiethyl sulfide in hairless guinea pigs

Developing skin lesions on hairless guinea pigs due to 2,2'-dichlorodiethyl sulfide (sulfur mustard, HD) exposure were examined to determine the time course for the appearance of histopathologic markers in relationship to skin NAD+ and NADP+ content after HD exposure. Hairless guinea pig skin was exposed to HD for 8 min by means of a vapor cup. Skin punches were taken at 1, 2, 4, 8, 12, 16, 20 and 24 h after HD exposure. Intracellular edema (IE) appeared at 2 h and increased steadily over 24 h. Epidermal necrosis (EN) and pustular epidermatitis (PE) developed at 8 h and reached a maximum at 16 h. Follicular necrosis (FN) appeared at 8 h and increased up to 24 h. Microvesicles (MV) developed between 12-16 h reaching a maximum at 24 h. Niacinamide (750 mg/kg, ip) pretreatment (30-min) reduced the incidence of MV (40%) and FN (45%) at 24 h, but did not reduce IE, EN, or PE. In all animals, skin NAD+ content decreased to a minimum (20% of control) at 16 h, but NAD+ decreases did not precede microvesicle formation. Skin NADP+ content increased (260%) between 1-2 h and returned to control at 4 h. Skin cell NADP+ increases may be indicative of an early phase of cellular oxidative stress that may contribute to HD-induced dermal pathogenesis. Since NAD+ reductions did not precede microvesication and NAM-induced increases in NAD+ content did not delay or reduce early cellular alterations, the contributory role of NAD+ to microvesicle formation may be limited and other biochemical changes should be investigated.

Sulfur mustard-induced microvesication in hairless guinea pigs: effect of short-term niacinamide administration

It has been postulated that sulfur mustard (HD) damage may activate poly(ADP-ribose) polymerase (PADPRP), resulting in depletion of cellular NAD+. This biochemical alteration is postulated to result in blister (vesicle) formation. It has been previously demonstrated that niacinamide (NAM), an inhibitor of PADPRP and a precursor for NAD+ synthesis, may be useful as a pretreatment compound to reduce HD-induced microvesication. The present study was undertaken to determine whether niacinamide's protective action could be extended beyond 24 hr and if the degree of microvesication is related to changes in skin NAD+ content. HD exposures were made by vapor cup to hairless guinea pigs. Niacinamide (750 mg/kg, ip) given as a 30-min pretreatment did not reduce the degree of microvesication 72 hr after HD compared to saline controls. However, niacinamide given as a 30-min pretreatment and at 6-, 24-, and 48-hr after HD, exhibited a 28% reduction in microvesication 72 hr after HD. Skin NAD+ content at 72 hr after HD was depleted by approximately 53% in the saline and NAM-treated groups. Skin NAD+ content was depleted despite NAM administration. Niacinamide did not reduce the degree of erythema at 48 or 72 hr. These results suggest that niacinamide's protective effect against HD-induced microvesication may be extended for at least 72 hr, but NAM levels must be sustained during the post-HD period. The link between maintenance of skin NAD+ and reductions in microvesication is still uncertain.

Monoclonal antibodies against soman: characterization of soman stereoisomers

Hybridomas were produced which expressed monoclonal anti-soman antibodies as determined by microtiter enzyme-linked-antibody immunoassay (EIA). Each of these antibodies was titrated using a competitive inhibition enzyme immunoassay (CIEIA) with a variety of test ligands. The ligands used included soman (a racemic mixture), sarin, tabun, and each of the four stereoisomers of soman (C+ P+, C+ P-, C-P+ and C-P-). In all cases the antibodies tested exhibited IC50 values of 10(-4)-5 x 10(-6) M for soman. When sarin or tabun was used as a ligand, the antibodies exhibited no cross reactivity. All of the antibodies cross reacted with the four soman stereoisomers. A second group of hybridomas were produced which expressed monoclonal antibodies against CsPs-soman. These antibodies were used to make preliminary absolute chiral assignments to the four soman stereoisomers.

Use of the accelerating rotarod for assessment of motor performance decrement induced by potential anticonvulsant compounds in nerve agent poisoning

The accelerating rotarod was used to assess motor performance decrement in rats after administration of candidate anticonvulsant compounds (acetazolamide, amitriptyline, chlordiazepoxide, diazepam, diazepam-lysine, lorazepam, loprazolam, midazolam, phenobarbital and scopolamine) against nerve agent poisoning. All compounds were tested as the commercially available injectable preparation except for diazepam-lysine and loprazolam, which are not FDA approved. A peak effect time, as well as a dose to decrease performance time by 50% from control (PDD50), was determined. The calculated PDD50 (mumol/kg) values and peak effect times were midazolam, 1.16 at 15 min; loprazolam, 1.17 at 15 min; diazepam-lysine, 4.17 at 30 min; lorazepam, 4.98 at 15 min; diazepam, 5.27 at 15 min; phenobarbital, 101.49 at 45 min; chlordiazepoxide, 159.21 at 30 min; scopolamine, amitriptyline and acetazolamide did not demonstrate a performance decrement at any of the doses tested. The PDD50 values were compared with doses which have been utilized against nerve agent-induced convulsions or published ED50 values from standard anticonvulsant screening tests (maximal electroshock [MES] and subcutaneous pentylenetetrazol [scMET]). The results suggest that at anticonvulsant doses against nerve agents, all the benzodiazepines and phenobarbital have the potential to cause a performance decrement, whereas candidate anticonvulsants of the non-benzodiazepine or non-barbiturate type would not be expected to demonstrate this effect on motor performance. It is concluded that compounds such as acetazolamide, amitriptyline and scopolamine offer alternatives to the highly decrementing benzodiazepines and phenobarbital and should be further tested as anticonvulsant candidates against nerve agent intoxication.