The jugular dural fold-a helpful skull base landmark to the cranial nerves

During a retrosigmoid (or combined retrolabyrinthine-retrosigmoid) approach to the posterior fossa for vestibular neurectomy or removal of small acoustic neuromas, a white dural fold is a consistent landmark to cranial nerves VII through XII. This fold of dura appears as a white linear structure extending from the foramen magnum across the sigmoid sinus, attaching to the posterior aspect of the temporal bone, anterior to the vestibular aqueduct. The name "jugular dural fold" is suggested for this landmark. The jugular dural fold overlies the junction of the sigmoid sinus and the jugular foramen. As measured in formalin-fixed cadaver heads, the overall length of the jugular dural fold is 20.8 mm (+/- 2.9 mm). The cochleovestibular nerve lies 9.9 mm (+/- 1.5 mm) anterior to the superior aspect of the jugular dural fold, the glossopharyngeal nerve lies 9.5 mm (+/- 1.6 mm) anterior to the midpoint of the jugular dural fold, and the operculum of the vestibular aqueduct lies 6.6 mm (+/- 0.7 mm) posterior to the jugular dural fold. Intraoperative measurements in patients undergoing combined retrolabyrinthine-retrosigmoid vestibular neurectomy show an overall length of the jugular dural fold of 16.3 mm (+/- 1.9 mm). The cochleovestibular nerve lies 8.6 mm (+/- 1.3 mm) anterior to the superior aspect of the jugular dural fold, the glossopharyngeal nerve lies 8.6 mm (+/- 1.3 mm) anterior to the midpoint of the jugular dural fold, and the operculum lies 7.5 mm (+/- 0.8 mm) posterior to the jugular dural fold. The jugular dural fold can be used as a reliable landmark for rapidly locating cranial nerves in the posterior fossa.     

Revision total hip arthroplasty using a cementless acetabular component: technique and results

One hundred thirty-eight acetabular revisions for aseptic loosening were performed in 132 patients using a cementless hemispherical component coated with titanium mesh and inserted with supplemental screw fixation. Twelve patients died, 9 were lost to follow-up and 6 could not return, leaving 111 patients (115 hips) at mean 100 months follow-up. Thirteen hips required revision (11%); 4 for recurrent dislocations, 6 for sepsis, and 3 stable cups were revised (at the time of stem revision). No cup was revised for aseptic loosening. Radiographic review was available for 105 patients (109 hips) at mean 98 month follow-up (78 to 135 months). One hundred cups (91%) were considered stable. Seven cups were possibly unstable (7%), one cup was probably unstable (1%), and one septic hip had an unstable cup (1%). Four percent of the cups showed a complete radiolucency. A partial progressive radiolucency was seen in 3%, a partial nonprogressive radiolucency in 54%, and no radiolucency was present in 39%. A screw radiolucency was seen in 2%, and osteolysis at the cup margin in 4%. Revision of the acetabulum with a cementless porous-coated hemispherical fiber-metal component seems to be superior to the results reported for acetabular revisions with cement at similar follow-up.     

Evaluation of a protocol for the non-operative management of perforated peptic ulcer

BACKGROUND: The non-operative management of perforated peptic ulcer has previously been shown to be both safe and effective although it remains controversial. A protocol for non-operative management was set up in this hospital in 1989. Adherence to the guidelines in the protocol has been audited over a 6-year period with a review of outcome. METHODS: The case-notes of patients with a diagnosis of perforated peptic ulcer were reviewed. Twelve guidelines from the protocol were selected for evaluation of compliance to the protocol. RESULTS: Forty-nine patients underwent non-operative treatment initially. Eight patients failed to respond and underwent operation. Complications included abscess formation (seven patients), renal failure (one), gastric ileus (one), chest infection (two), and cardiac failure and stroke (one). Four deaths occurred in this group. Adherence to certain protocol guidelines was poor, notably those concerning prevention of thromboembolism, use of antibiotics, use of contrast examination to confirm the diagnosis and referral for follow-up endoscopy. Two gastric cancers were detected on subsequent endoscopy. CONCLUSION: This experience demonstrates that non-operative treatment can be used successfully in a general hospital. Adherence to protocol guidelines was found to be variable and the protocol has therefore been simplified. This study highlights the need for an accurate diagnosis and the importance of follow-up endoscopy.     

Does effective postoperative pain management influence surgical morbidity?

It has been assumed that adequate postoperative pain relief will improve outcome from surgery, but several controlled trials have demonstrated that pain treatment with nonsteroidal anti-inflammatory drugs, patient-controlled analgesia or epidural techniques will not significantly improve outcome after major procedures. In lower body procedures, however, intra- and early postoperative pain relief with epidural or spinal anaesthesia reduces blood loss and thromboembolic complications. It is hypothesized that effective postoperative pain relief may significantly improve outcome only if integrated into a multimodal rehabilitation program.     

The incidence of deep venous thrombosis after arthroscopic knee surgery

We retrospectively reviewed the records of 2050 arthroscopic knee surgeries performed at The Orthopedic Specialty Hospital from January 1993 to December 1994. The number of clinically detected deep venous thromboses, with confirmation by duplex ultrasonography, was determined. Prospectively, preoperative and postoperative duplex ultrasonographic images were completed on 239 patients divided into 2 groups: those undergoing nonligament, intraarticular arthroscopic surgery (N = 131) and those undergoing arthroscopically assisted ligament surgery and extraarticular or osteotomy surgery (N = 108). For the retrospective study, the incidence of deep venous thrombosis was 0.24%. Prospectively, seven total deep venous thromboses were identified (rate, 2.9%), with five being identified within 8 days of surgery in asymptomatic patients (rate, 2.1%). There were no statistically significant associations or correlations between the development of deep venous thrombosis and patient personal data or surgical variables, respectively. The difference in the rate of deep venous thrombosis between the two prospective groups was not statistically significant; however, patients who had more invasive surgery tended to be at higher risk for developing deep venous thrombosis. A cost-benefit analysis did not support the routine use of duplex ultrasonography to detect deep venous thrombosis in patients undergoing arthroscopic knee surgery.     

The fate of stable cemented acetabular components retained during revision of a femoral component of a total hip arthroplasty

BACKGROUND: The decision as to whether to revise or retain a well fixed cemented acetabular component during revision of a femoral component is especially difficult; the rate of loosening of cemented acetabular components is high, whereas that of porous-coated acetabular components inserted during revision is low. However, removal of a well fixed cemented acetabular component can result in increased operative morbidity and cost and in loss of acetabular bone. Data that can be used to predict the long-term survival of retained well fixed cemented acetabular components are therefore needed. METHODS: We studied the five to thirteen-year clinical and radiographic results in a group of twenty-six consecutive patients in whom a well fixed cemented acetabular component had been retained during revision of a femoral component. Typical demographic data on the patients and information about the components were recorded, and the cemented acetabular components were graded as A through F, according to the system of Ranawat et al., at the time of the femoral revision. The average duration of follow-up was 8.4 years (range, 5.0 to 12.7 years). No patient was lost to follow-up. RESULTS: Four acetabular components (15 percent) had progressive radiolucency (at forty-eight, forty-eight, fifty-nine, and seventy-five months after the femoral revision) and were considered radiographically loose despite not being associated with symptoms. All four components were graded as either E or F at the time that they were retained during the femoral revision; radiographic loosening was significantly related to these two grades (p < 0.01). No acetabular component with a grade of A, B, C, or D loosened. The components that loosened had been in vivo for a relatively shorter, as opposed to longer, duration before the femoral revision compared with the components that did not loosen (p < 0.05). CONCLUSIONS: Retention of the well fixed cemented acetabular components was associated with good clinical results but with a 15 percent rate of loosening. Revision of a cemented acetabular component solely on the basis of the duration that it was in vivo or whether a previous revision had been done does not appear to be warranted. Our findings suggest that acetabular components with a grade of A, B, C, or D at the time of a femoral revision may be retained, as these components continued to function at the time of the five to thirteen-year follow-up in the current study.     

ELISA-quantitation of phosphorylated tau protein in the Alzheimer's disease brain

A reliable, sensitive and specific sandwich ELISA for the quantitation of paired helical filament (PHF) tau in human brain was developed using well-defined monoclonal antibodies. We examined rapid-autopsy-derived brain tissue from 21 neuropathologically confirmed Alzheimer's disease (AD) patients and 14 nondemented controls, matched for age, sex and postmortem delay times. We demonstrated significant elevations of phosphorylated tau levels in the frontal and parietal cortex as well as in the hippocampus of AD patients as compared to the nondemented controls. No difference was observed in the cerebellum. Phosphorylated tau levels measured by ELISA were significantly correlated with the presence or absence of neurofibrillary tangles.     

On burn injuries related to airbag deployment

Airbags have been shown as a vital, supplemental restraining device that save lives and reduce morbidity associated with motor vehicles crashes. However, as with any developing technology, airbags have also been identified in some instances, as the source of injuries which, have been well described in the literature. To a significantly lesser degree, burns due to airbag deployment (about 7-8% of these injuries) have been reported. These injuries will be seen more frequently as more vehicles are equipped with airbags and should be suspected in drivers and passengers involved in accidents in which airbags have been activated. This article, reviews the various types of burns and their pathogenesis, found in crashes involving airbag deployments.