The Postoperative Prognosis of Thoracic Ossification of the Ligamentum Flavum can be Described by a Novel Method: The Thoracic Ossification of the Ligamentum Flavum Score.

OBJECTIVE

To create an available thoracic ossification of the ligamentum flavum (TOLF) score as a rudimentary predictor for the postoperative prognosis of TOLF.

METHODS

A retrospective review was conducted for all patients with TOLF who received surgical decompression from April 2012 to February 2019. The TOLF score consists of 5 components, namely, the age at surgery (1-3 points), diabetes mellitus (1 point), preoperative duration of symptoms (1-2 points), spinal canal axial remnant area ratio (0-2 points), and intramedullary signal change on magnetic resonance imaging (1 point). The scores of all patients were calculated and analyzed for their correlation with the postoperative recovery ratio. In addition, intraoperative blood loss, urinary catheter indwelling time, cerebrospinal fluid leakage, and postoperative neurologic deterioration were also measured.

RESULTS

A total of 64 patients were included. The mean TOLF score at the final follow-up was 4.6 points in the excellent group (20 patients), 5.0 points in the good group (29 patients), and 7.3 points in the poor group (15 patients). A higher TOLF score predicts lower postoperative recovery ratio (P = 0.000), longer urinary catheter indwelling time (P = 0.023), and higher incidence of postoperative neurologic deterioration (P = 0.000). However, no correlation was identified between the TOLF score and intraoperative blood loss (P = 0.755) or cerebrospinal fluid leakage (P = 0.911).

CONCLUSIONS

The TOLF score is a novel and rudimentary scoring system that describes the predictive factors that indicate the postoperative prognosis of TOLF.