Introduction: Pseudarthrosis after ACDF is not uncommon.Management of symptomatic pseudarthrosis is challenging.Posterior cervical approach with use of cervical interfacet spacer(CIS) is a novel allograft technology that offers the potential to provide indirect neuroforaminal decompression while simultaneously enhancing fusion by placing the allograft in compression.
Methods: Medical records of patients who underwent posterior cervical fusion using CIS and instrumentation for symptomatic pseudarthrosis following ACDF from July 2011 to June 2014 were reviewed.Preoperative and postoperative patient derived outcome measures such as VAS score for neck and arm pain and NDI and upright lateral cervical radiographs were reviewed.Paired t-tests were used to compare preoperative and postoperative radiographic and patient derived outcome measures.
Results: There were nineteen patients with symptomatic cervical pseudarthrosis in the study.There were 6 men and 13 women with an average age of 54 years.(Range,31-65 years)Pre-operative symptoms included persistent neck and/or arm pain unresponsive to conservative treatment in all patients.The average follow up was 9.84 months.(Range,6m-16m)There was a significant improvement in VAS score for neck pain,(p<0.002)radicular arm pain (p < 0.004)and NDI score (p<0.05)after surgery with 83%,72% and 67% of patients showing improvement in their VAS neck pain,arm pain and NDI scores respectively.Fusion rate was high with fusion occurring at all levels treated for pseudarthrosis.One patient had pseudarthrosis at C7-T1 level which was unrelated to the index pseudarthrosis level and was not symptomatic at last follow up.There was small but insignificant improvement in cervical lordosis(mean difference 2°± 2.49°,p=0.12)and a small but insignificant worsening of C2-C7 SVA after surgery.(Mean difference,1.89mm,p= 0.30).The overall mean C2-C7 SVA both before and after surgery was less than 4 cm.
Conclusions: CIS provides an important fusion technique for posterior cervical fusion.This study demonstrates the clinical benefit of fusion in patients with symptomatic cervical pseudarthrosis using CIS. While fusion using CIS resulted in significant clinical improvement,the sagittal radiological parameters remains essentially unchanged.
Patient Care: Management of patients with cervical pseudarthrosis can be challenging. Our study which demonstrates the clinical benefit of posterior cervical fusion using newer interfacet spacers in patients with pseudarthrosis following anterior cervical fusion would help physicians understand the expected surgical outcome for these subgroup of
patients.A newer allograft technology is described which can provide surgeon with another graft option for posterior cervical fusion.
Learning Objectives: Understanding the clinical outcome following cervical arthrodesis in management of cervical pseudarthrosis using newer cervical interfacet spacers.