Progressive adult spinal deformity following placement of intrathecal opioid pump: a report of four cases.

INTRODUCTION

Placement of intrathecal opioid pumps (ITOP) for chronic pain is a rare, but described cause of progressive spinal deformity. Over the last two decades there has been several suspected cases at our institution. In this case series, we described the apparent association between placement of an intrathecal opioid pump and progression of spinal deformity.

METHODS

The medical records of a single surgeon working at a single institution were retrospectively queried for patients seen between 1995-2010 to identify patients with spinal deformity and an ITOP. All hospital records including notes, radiographs, and labs were reviewed and analyzed. Spine radiographs were measured using standard techniques and reported as Cobb angles. This project was IRB approved and no external funding was used.

RESULTS

In total, we identified four patients with spinal deformity after placement of an ITOP. These patients were adults, two males and two females (ages: 48-80 years), with a unique medical history. Each participant's radiographs showed a progression of the spinal deformity following placement of ITOP. All patients underwent subsequent posterior spinal fusion for treatment of their progressive spinal deformities.

CONCLUSION

In this series, we have shown an apparent association between the placement of ITOP and progression of deformity in both patients with and without existing spinal deformity. While it is impossible to discern causality, all patients in our series had radiographic and clinical evidence of spinal deformity progression after placement of intrathecal pumps. These findings may raise awareness of this rare, but major, complication. In those performing pump placement, we recommend continued clinical and radiographic monitoring, through routine follow-up.

LEVEL OF EVIDENCE: Level 4--Case series; case control study (diagnostic studies); poor reference standard; analyses with no sensitivity analyses.