[Lasegue's test as prognostic factor for patients undergoing lumbar disc surgery]

In patients operated for herniated lumbar disc it could be very useful to develop physical examination criteria that would allow early prediction of medium or long term clinical outcomes. The result of the Lasegue test after surgery depends on the occurrence of recurrent herniated disc and/or scar formation around the nerve root. Previous studies have shown the association between the result of Lasegue test, assessed 4 months after surgery, and the short term functional outcome.

To determine the prognostic value of postoperative Lasegue test in relation with medium term functional and clinical outcomes which were estimated by analyzing the functional grade, employment status, quality of life, reoperation for recurrent disc herniation, and the number of clinical revisions and imaging studies needed during the follow-up.

243 patients who underwent hemilaminectomy for lumbar herniated disc between 1996 and 2002 were studied. The Lasegue sign was tested 3 months after surgery. A modification of Spangfort's criteria (to measure the functional grade) and the 12-item Short-form health survey (SF-12) method (to measure the quality of life) were used to quantify outcomes at 12, 24 and 36 months after initial surgery.

This investigation has proved the prognostic value of Lasegue test assessed 3 months after initial surgery. A statistically significant correlation was found between a positive straight leg raising test and a poor functional status at 24 and 36 months, and the risk do not return to work because of persistent pain at 12, 24 and 36 months. A statistically significant correlation was also found between the result of the test and the frequency of reoperation for recurrent disc herniation and the number of clinical revisions and imaging control studies needed through the follow-up. Likewise, the prognostic value of Lasegue test on different aspects of quality of life (health perception, functional performances, poor social interaction and severe pain) analyzed at 24 and 36 months after surgery were also confirmed.

This study provides additional information about the predictive value of the straight leg raising tested 3 months after surgery on the clinical (diagnostic resources consumption, successive outpatient revisions, etc) and functional (quality of life, functional grade and return to work) outcomes assessed 24 and 36 months after initial surgery.