Clinical and radiological outcome after minimally invasive surgical approach for type II unstable odontoid fractures

INTRODUCTION

Anterior odontoid screw fixation is a valid surgical option for unstable odontoid fractures, as type II Anderson D'Alonzo fractures. Grauer further divided type II fractures in subtypes according to the fracture line, providing recommendations for implementation of screw fixation techniques.

OBJECTIVE

Primary endpoint of our study is to evaluate the postoperative results of minimally invasive odontoid screw insertion in terms of outcome, fusion rate and stability of cranio-cervical junction. Secondary endpoint was to investigate the influence of age or fractures' features on outcome and fusion rate.

MATERIALS AND METHODS

We report the clinical and radiological features of 32 patients harbouring unstable type II fractures operated by a minimally invasive odontoid screw insertion technique. All patients underwent a high resolution multiplanar CT in order to assess fracture features according to Grauer's classification; the integrity of ligaments was investigated by MRI. In addition, a preoperative neurological performance (modified Rankin Scale, mRS) was evaluated for patients either directly or interviewing their families. Follow-up at one, three and six months and 1 year have been performed (averaging 13.5 months) by cervical CT (fusion rate and stability) and mRS update. In order to investigate the influence of age on postoperative neurological performance, two groups (≤50 yrs, 9 pts/>50 yrs, 23 pts) were separately considered and analysed. Overall, we observed no surgery related complications. We also analysed the fusion rate and its correlation with patient age and Grauer's subtype of fracture.

RESULTS

At last available clinical follow-up, the preoperative performance was preserved (mRS 0/1: 24, 75%; mRS 2-4: 9, 15%) although with slight reduction of intact patients (mRS 0: 22 vs. 19; 71.8 vs. 59.3%). Younger patients (≤50 yrs) fared significantly better than older ones, achieving a good clinical outcome (mRS 0/1) in 100% vs. 69.5% (9/9 vs. 16/23 pts). Statistical analysis showed a fair correlation between age and outcome. Other factors such as sex and Grauer's type did not influence significantly the clinical outcome. Nine patients did not complete a full radiological follow-up and were therefore excluded from analysis of radiological outcome. Among the remaining 23 patients, only 25% of those who were followed three months or less showed fusion; conversely, all patients who have been examined from 6 to 48 months fused. Among the non-union patients, two underwent a second surgery by posterior approach.

CONCLUSIONS

In our recent experience, the minimally invasive AOSF proved safe and effective in treating odontoid peg fractures. Selection based on Grauer's type is mandatory to achieve best results. While in the elderly, an anterior approach is well accepted as the first choice treatment, we recommend that this option should be offered as a suitable alternative to Halo or orthosis also in younger patients since it provides prompt, excellent clinical outcome and high fusion rate especially in this age group.

[The usefulness of bioimpedance in patient monitoring in an intensive-therapy heart-surgery unit: a comparison with thermodilution]

Haemodynamic monitoring of intensive care unit (ICU) patients can be carried out by thermodilution system. This method is invasive, does not give a continuous monitoring and complications can occur. Thoracic electrical bioimpedance (TB), a non invasive, fast, easily repeatable method, is able to measure some important haemodynamic parameters: end diastolic volume (EDV), stroke volume, cardiac output (CO), ejection fraction (EF), some contractility indexes, systemic vascular resistances (SVR) and cardiac work. The aim of the present study is to compare CO and SVR obtained by thermodilution with the same indexes obtained by TB. Therefore, 20 ICU patients (12 males and 8 females, mean age 54 +/- 11 years) were studied. Out of them, 16 had been submitted to cardiac surgery in the previous 7 days and 4 were waiting for cardiac surgery. The patients were divided in 2 groups: Group A (N 4) included patients with valvular malfunction and/or cardiac arrhythmias and Group B (N 16) included patients with normal valvular function and sinus rhythm. CO obtained by TB was well related with the one obtained by invasive (INV; r = 0.878; p < 0.001). The mean value of difference of the 2 methods was 12.29 +/- 11.83 for the whole group of 20 patients but it was 26.07 +/- 14.16 in the Group A and 8.84 +/- 8.09 in the Group B confirming the less reliability of the method in patients with abnormal valvular function or in the presence of cardiac arrhythmias. As a consequence, SVR obtained by TB and INV resulted well related (r = 0.752; p < 0.001). The mean value of differences was 11.14 +/- 9.01 in the group of 20 patients and particularly 19.55 +/- 10.87 in the Group A and 9.04 +/- 7.07 in the Group B. In a subgroup of 9 patients, CO was measured at successive times (0, 30, 60, 90 min) by both TB and INV; when comparing the 2 CO values a significant correlation was observed. In conclusion, TB represents a valid method in haemodynamic monitoring of the ICU patients.

Myocardial revascularization in women

To compare the results of coronary artery bypass in women and men, we reviewed our experience from January 1976 through June 1989. During this period, 170 women with coronary artery disease but with no other cardiac abnormalities underwent coronary artery bypass. We compared this group with a group of 150 men, matching them according to age, presence of angina, extent of disease, and surgical treatment. Preoperative clinical features, surgical data, and early and late results were analyzed. The operative mortality was similar between groups (2.9% for women vs 2.6% for men). The women, however, were more frequently overweight (54% vs 15%; p <0.001) and more often had the following: diabetes mellitus (34% vs 20%; p <0.01), a coronary artery diameter of <1.8 mm (64% vs 29%; p <0.001), poor saphenous vein quality (50% vs 16%; p <0.001), and incomplete revascularization (20% vs 4%; p <0.001). After a mean follow-up of 6 years, the women also had a higher incidence of recent-onset myocardial infarction (31% vs 12%; p <0.001) and a greater tendency to be symptomatic (48% vs 19%; p <0.001). The 12-year cumulative survival rates were similar in both groups (76.2% for women vs 77.1% for men). According to logistic regression analysis of the significantly different variables, the only independent determinants of postoperative asymptomatic status were satisfactory coronary artery caliber, good saphenous vein quality, and complete revascularization. We conclude that poorer functional results after coronary artery bypass surgery in women may be caused by a poorer quality of revascularization, which in turn is a result of smaller coronary artery diameter, worse distal runoff, and less satisfactory vein quality.

[Isolated traumatic rupture of the ascending aorta. Clinical case and review of the literature]

Rupture of the descending aorta after severe blunt chest trauma is a well recognised injury. Instead, isolated traumatic rupture of the ascending aorta is rarely diagnosed, with only five cases reported in the literature. A case of isolated traumatic rupture of the ascending aorta is here reported and the role of medical treatment is described.