Single-stage combined decompression for patients with tandem ossification in the cervical and thoracic spine

Retrospective study of clinical outcomes of single-staged combined cervical and thoracic decompression for patients with tandem ossification (TO).

To describe primary clinical outcomes of this procedure. TO is introduced to described a double ossification lesion of the posterior longitudinal ligament (OPLL) or the ligament flavum (OLF) at the cervical, thoracic and lumbar spine. In clinical practice, cervical OPLL combined with thoracic OPLL or/and OLF are the most common types of TO. However, little is known about the clinical outcomes of surgical treatment and there is no consensus on the optimal treatment to this combined disorder.

Between January 2005 and December 2008, 15 patients of this complicated phenomenon were treated by single-staged combined cervical and thoracic decompression in conditions where patients' general condition allowed and individuals agreed on. Surgical intervention, perioperative complications, and clinical outcomes were reviewed in these 15 TO patients who were followed up for more than 2 years (range 2-5 years). Clinical symptoms were evaluated using the JOA scoring system and activity of daily life was evaluated by Nurick classification before surgery, at 6 months postoperatively, and at final follow-up. Patient satisfaction was determined at final follow-up.

The mean blood loss was 1,553.3 ± 735.7 ml (range 700-2,900 ml) and the mean operation time was 280.7 ± 53.6 min (range 220-370 min). The important intraoperative and postoperative complications recorded in medical documents included CSF leakage, hematoma, C5 palsy and neurological deterioration. The JOA score was significantly higher 6 months after surgery (8.1 ± 1.8 points vs. 11.0 ± 1.6 points, p < 0.0001), and there was no significant change between 6 months after surgery and final follow-up (11.0 ± 1.6 points vs. 11.3 ± 2.1, p = 0.5894). The mean Nurick classification significantly improved from grade 3.6 ± 0.7 before surgery to grade 2.5 ± 0.9 at 6 months after surgery (p < 0.001), and well maintained as grade 2.3 ± 1.0 at final follow-up (p = 0.3343). Three patients had satisfaction scores of 3 points, 5 had scores of 2 or 1 point, and 2 had score of 0 point. Pearson correlation analysis showed a significant positive correlation between satisfaction score and JOA score (r = 0.6493, p = 0.0093), and a significant negative correlation between satisfaction score and Nurick classification (r = -0.5941, p = 0.0195). Besides, perioperative complications and progression of tandem ossification which needed revision surgery had significant adverse effect on patients' satisfaction.

The results showed that single-staged combined decompression could provide comparable clinical outcomes, and patients' satisfaction was significantly related with postoperative neurological function. In addition, satisfaction score could be decreased by perioperative complications and progression of tandem ossification. Thus, this aggressive surgical strategy should be used more carefully with emphasis on preoperative communication with patients.