[Effectiveness of transarticular approach in treating thoracic spinal stenosis of calcified ligament]

To investigate the effectiveness of transarticular approach in treating thoracic spinal stenosis due to ossification of ligamentum flavum (OLF) and ossification of posterior longitudinal ligament (OPLL) at the same level.

A retrospective analysis was performed in 35 patients with single-level thoracic spinal stenosis of calcified ligament who accepted transarticular approaching operation between January 2006 and March 2008. There were 12 males and 23 females with an age range of 40-67 years (mean, 58.6 years), including 16 cases of thoracic OLF, 11 cases of thoracic OPLL, and 8 cases of thoracic OPLL and OLF. The disease duration was 8-48 months (mean, 16 months). The affected segments included T2, 3 in 4 cases, T3, 4 in 3 cases, T4, 5 in 1 case, T6, 7 in 3 cases, T7, 8 in 1 case, T8, 9 in 2 cases, T9, 10 in 5 cases, T10, 11 in 9 cases, and T11, 12 in 7 cases. CT and MRI were taken to definite the ossification position and the condition of thoracic spinal stenosis. The Japanese Orthopaedic Association (JOA) score was 6.1 +/- 1.3 before operation. According to Otani scoring system, the results were excellent in 3 cases, good in 16 cases, fair in 11 cases, and poor in 5 cases.

All operations were successful, and no nerve injury occurred. All incisions healed at stage I. Cerebrospinal fluid leakage occurred in 5 cases, and recovered after symptomatic treatment. One case had epidural hematoma 6 hours after operation, and the muscle strength recovered after symptomatic treatment. All cases were followed up 1.5-2.6 years (mean, 2.1 years) and the symptoms were improved in different degrees; no neurological symptoms deteriorated and spinal instability occurred. The JOA score had a significant recovery at 3 months (9.2 +/- 1.8) and at last follow-up (9.6 +/- 2.3) when compared with preoperative value (P < 0.05). At last follow-up, the rate of the clinical improvement was 71.43% +/- 18.20%. According to Otani scoring system at last follow-up, the results were excellent in 12 cases, good in 15 cases, fair in 6 cases, and poor in 2 cases with an excellent and good rate of 77.14%, showing significant difference when compared with preoperative value (u = 2.711, P = 0.007).

The transarticular approach in treating thoracic spinal stenosis of calcified ligament can obtain good clinical results. Moreover, extra attention should be paid to during operation so as to avoid catastrophic spinal cord injury.