Validation of an endoscopic flavectomy training model

OBJECTIVE

to validate a lumbar spine endoscopic flavectomy simulator using the construct method and to assess the acceptability of the simulator in medical education.

METHODS

thirty medical students and ten video-assisted surgery experienced orthopedists performed an endoscopic flavectomy procedure in the simulator. Time, look-downs, lost instruments, respect for the stipulated edge of the ligamentum flavum, regularity of the incision, GOALS checklist (Global Operative Assessment of Laparoscopic Skills), and responses to the Likert Scale adapted for this study were analyzed.

RESULTS

all variables differed between groups. Procedure time was shorter in the physician group (p < 0.001). Look-downs and instrument losses were seven times greater among students than physicians. Half of the students respected the designated incision limits, compared to 80% of the physicians. In the student group, about 30% of the incisions were regular, compared to 100% in the physician group (p < 0.001). The physicians performed better in all GOALS checklist domains. All the physicians and more than 96% of the students considered the activity enjoyable, and approximately 90% believed that the model was realistic and could contribute to medical education.

CONCLUSIONS

the simulator could differentiate the groups' experience level, indicating construct validity, and both groups reported high acceptability.

Evaluation of lung volumes, vital capacity and respiratory muscle strength after cervical, thoracic and lumbar spinal surgery

CONTEXT AND OBJECTIVE

Studies have shown that physiopathological changes to the respiratory system can occur following thoracic and abdominal surgery. Laminectomy is considered to be a peripheral surgical procedure, but it is possible that thoracic spinal surgery exerts a greater influence on lung function. The aim of this study was to evaluate the pulmonary volumes and maximum respiratory pressures of patients undergoing cervical, thoracic or lumbar spinal surgery.

DESIGN AND SETTING

Prospective study in a tertiary-level university hospital.

METHODS

Sixty-three patients undergoing laminectomy due to diagnoses of tumors or herniated discs were evaluated. Vital capacity, tidal volume, minute ventilation and maximum respiratory pressures were evaluated preoperatively and on the first and second postoperative days. Possible associations between the respiratory variables and the duration of the operation, surgical diagnosis and smoking status were investigated.

RESULTS

Vital capacity and maximum inspiratory pressure presented reductions on the first postoperative day (20.9% and 91.6%, respectively) for thoracic surgery (P = 0.01), and maximum expiratory pressure showed reductions on the first postoperative day in cervical surgery patients (15.3%; P = 0.004). The incidence of pulmonary complications was 3.6%.

CONCLUSIONS

There were reductions in vital capacity and maximum respiratory pressures during the postoperative period in patients undergoing laminectomy. Surgery in the thoracic region was associated with greater reductions in vital capacity and maximum inspiratory pressure, compared with cervical and lumbar surgery. Thus, surgical manipulation of the thoracic region appears to have more influence on pulmonary function and respiratory muscle action.

Correlations between radiographic, magnetic resonance and histological examinations on the degeneration of human lumbar intervertebral discs

CONTEXT AND OBJECTIVE

There is controversy regarding which imaging method is best for identifying early degenerative alterations in intervertebral discs. No correlations between such methods and histological finds are presented in the literature. The aim of this study was to correlate the thickness of intervertebral discs measured on simple radiographs with the degree of degeneration seen on magnetic resonance images and the histological findings relating to nerve ends inside the discs.

DESIGN AND SETTING

Cross-sectional correlation study on the lumbar spines of human cadavers, at Universidade Federal de São Paulo (Unifesp), São Paulo, Brazil.

METHODS

Ten lumbar spinal columns were extracted from human cadavers and subjected to magnetic resonance imaging and simple radiography. They were classified according to the degree of disc degeneration seen on magnetic resonance, and the thickness of the discs was measured on radiographs. The intervertebral discs were then extracted, embedded in paraffin and analyzed immunohistochemically with protein S100, and the nerve fibers were counted and classified.

RESULTS

No correlation was observed between the thickness of the intervertebral discs and the degree of degeneration seen on magnetic resonance images. Only the uppermost lumbar discs (L1/L2 and L2/L3) presented a correlation between their thickness and type I and IV nerve endings.

CONCLUSION

Reduced disc thickness is unrelated to increased presence of nerve ends in intervertebral discs, or to the degree of disc degeneration.

Prevalence of scoliosis among school students in a town in southern Brazil

CONTEXT AND OBJECTIVE

Scoliosis is not a diagnosis, but a description of a structural alteration that occurs in a variety of conditions. Progression of the curvature during periods of rapid growth may result in severe deformity, which may be accompanied by cardiopulmonary compromise. This study had the aims of measuring the prevalence of scoliosis among students in the fifth to eighth school years and investigating possible associations between the presence of scoliosis, body overweight and the weight of school materials.

DESIGN AND SETTING

Analytical cross-sectional study developed in the municipality of Carlos Barbosa, Rio Grande do Sul, Brazil.

METHODS

A total of 1340 students were evaluated. The variables studied were the prevalence of scoliosis, type of school, location of the school, age, school year, sex, body weight, prevalence of excessive school material weight, height, body mass index (BMI) and spinal alignment measurements.

RESULTS

The prevalence of scoliosis was 1.4%; shoulder and scapula asymmetry, 6.6%; forearm and trunk asymmetry, 4.0%; spinal misalignment, 1.9%; Thales triangle asymmetry, 6.4%; body overweight, 19.8%; and carrying of excessively heavy school materials, 27%. The study did not find any statistically significant association between scoliosis and body overweight, or between scoliosis and excessive weight of school materials.

CONCLUSIONS

The prevalence of scoliosis in this school-based sample was low. No correlation was found between this clinical condition and the other variables.