Radiologic and clinical outcomes of surgery in high grade spondylolisthesis treated with temporary distraction rod

Abstract

Background: Surgical techniques used in the treatment of patients with high grade lumbar spondylolisthesis (> 50% slippage) are usually associated with a great deal of controversies. We aim to evaluate the surgical outcomes of high grade spondylolisthesis treated with an intraoperative temporary distraction rod.

Methods: We retrospectively studied 21 patients (14 females and 7 males), aged 50.4 ± 9.2 years, who had high grade lumbar spondylolisthesis that was treated with intraoperative temporary distraction rods, neural decompression, pedicular screw fixation, and posterolateral fusion involving one more intact upper vertebra. The mean follow-up period was 39.2 months. Radiologic and clinical outcomes were measured by slip angle, slip percentage, correction rate, Oswestry Disability Index (ODI), visual analogue scale (VAS), patient's satisfaction rate in the pre- and postoperative period. Data were analyzed by SPSS ver. 11.5.

Results: Analysis of the preoperative visits and final follow-up visits indicated that surgery could improve ODI, lumbar VAS, and leg VAS from 60.5% to 8.2%, from 6.7 to 2.2, and from 6.9 to 1.3, respectively. Slip angle and slip percentage were also changed from -8° to -15° and from 59.2% to 21.4%, respectively. Mean correction rate at the final follow-up visit was 64.1%. Loss of correction was insignificant and a neurologic complication occurred in one patient due to misplacement of one screw. Excellent and good levels of satisfaction were observed in 90.5% of the patients.

Conclusions: In the surgical treatment of refractory high grade spondylolisthesis, the use of a temporary distraction rod to reduce the slipped vertebra in combination with neural decompression, posterolateral fusion, and longer instrumentation is associated with satisfactory clinical and radiologic outcomes.

Keywords: Radiology; Spondylolisthesis; Surgery; Treatment outcome.

Fig. 1

Schematic representation of reduction stages. In stage one, gentle distraction is applied to the upper and lower vertebrae. In stage two, gentle tightening of the intermediate (slipped) pedicle screws is performed.

Fig. 2

(A) A 48-year-old female with high grade spondylolisthesis (slip percentage 59%). She had a previous history of femoral shaft fracture. (B) This figure shows L5 laminectomy and the temporary distraction rod along with supra- and infralaminar hooks in S1 and L3, respectively. Pieces of cotton are placed on the dura mater for more protection. (C) Postoperative lateral radiograph shows a nearly perfect reduction (9% slip percentage with 85% correction rate).