"IV+V+VI" Circumferential Decompression Technique for Thoracic Myelopathy Caused by the Ossification of Posterior Longitudinal Ligament or Hard Disc Herniation.

STUDY

DESIGN

A retrospective study.

OBJECTIVE

The aim of this study was to describe a novel posterior approach, circumspinal decompression technique "IV+V+VI" for ossification of the posterior longitudinal ligament (OPLL) or hard disc herniation (HDH) in thoracic spine and assess its safety and efficacy.

SUMMARY OF BACKGROUND DATA: Thoracic myelopathy caused by OPLL or HDH is a rare but intractable disorder that can only be effectively treated with surgery. Nevertheless, few studies have reported on a detailed resection of OPLL or HDH using a single posterior approach and no consistent procedures have been established.

METHODS

Fifteen consecutive patients with single-level OPLL or HDH who were treated with this novel technique at our center between January 2016 and June 2017 were recruited. The perioperative complications, operation time, blood loss, pre- and postoperative neurological statuses were recorded and analyzed. Neurological status was evaluated with a modified Japanese Orthopaedic Association (JOA) scale and the neurological recovery rate was calculated using the Hirabayashi's Method.

RESULTS

All the included patients underwent one-stage posterior circumferential decompression. The average age at surgery was 43.3 ± 12.8 years. Eight cases were diagnosed with HDH, four with OPLL, and three with OPLL+OLF (ossification of the ligamentum flavum). The mean operation time was 109.9 ± 25.3 minutes with an average blood loss of 433.3 ± 221.8 mL. The mean follow-up period was 33.1 ± 7.5 months. Five patients experienced a dural tear, whereas another case experienced a transient numbness in the right lower limb. All these patients were treated conservatively and their neurological function recovered well at the final follow-up. The average JOA score increased from 5.8 ± 1.9 before surgery to 10.2 ± 1.0 postoperatively, and the average recovery rate was 87.2%.

CONCLUSION

The "IV+V+VI" technique is a safe and effective method for thoracic OPLL and HDH resection. It can be used as a standard surgical procedure for thoracic spinal circumferential decompression.

LEVEL OF EVIDENCE: 4.