PEEK cages as a potential alternative in the treatment of cervical spondylodiscitis: a preliminary report on a patient series

Abstract

The surgical management of cervical spondylodiscitis consists of the resection of the affected disc, the decompression of the cervical spinal cord, followed by the stabilization using an autologous bone graft or a titanium implant combined with a ventral plate fixation. Until now, there were no studies about the practicability and putative safety of PEEK cages in cervical spine infection. Now, we present the history of five patients suffering from neurological deficits and septicemia caused by mono- or bisegmental pyogenic cervical discitis and intraspinal abscess without severe bone destruction. Patients were treated surgically by discectomy, decompression, and ventral spondylodesis. The disc was replaced by a PEEK cage without additional fixation. Progressive bony fusion and complete regression of the inflammatory changes was demonstrated 7-8 months later by a computer assisted tomography and contrast enhanced magnetic resonance imaging, respectively. The vertebral alignment changed minimally; the cages developed only a slight average subsidence. The clinical symptoms improved in all patients significantly. Neck pain or instability was never observed. Nevertheless, prospective investigations of a larger patient series are mandatory. We suppose that the use of PEEK cages represents a potential and safe alternative in the treatment of cervical spondylodiscitis in selected patients.

Fig. 1

Time course of diagnostic imaging during cervical spondylodiscitis with an epidural component (a–d), after surgical decompression and ventral spondylodesis and subsequent targeted antibiotic therapy (e–h). a–d MRI in sagittal (a) and transversal (c) T2 sequence illustrates the mass effect of the acute spondylodiscitis with prevertebral and epidural abscess formation. Gadolinium enhanced T1 sequences in sagittal (b) and transversal (d) orientation demonstrate the contrasted rim and the hypointense, fluid center of the abscesses. The arrows label the margins of the prevertebral and epidural abscesses. The stars mark the former intervertebral disc spaces before cage interposition. e–h The postoperative MRI after 7 months clearly shows the totally decompressed spinal conditions. The sagittal (e) and transversal (g) T2 weighted images make the perimedullary rim of cerebrospinal fluid visible. The sagittal (f) and transversal (h) T1 weighted images after intravenous administration of gadolinium-DTPA illustrate the decreased inflammatory situation without any enhancement of gadolinium. The stars mark the levels of the intervertebral discs. The images belong to patient no. 4 from the Tables 1 and 2

Fig. 2

Postoperative CT and MRI imaging after 7 months of the same patient as in Fig. 1. a, b The transversal CT images and their sagittal reconstruction illustrate the total bony fusion between the involved cervical levels. The stars mark the involved levels C5–C7. The patient did not demonstrate any signs of neck pain, micro- or macroinstability. The patient did not demonstrate any signs of neck pain, micro- or macroinstability. The images belong to patient no. 4 from the Tables 1 and 2. Artifacts from metal markers within PEEK cages might be misdiagnosed as lucencies

Fig. 3

Preoperative imaging of a cervical spondylodiscitis with prevertebral und epidural abscesses, after surgical decompression and 9-months CT-control after monosegmental PEEK-cage spondylodesis. a, b Sagittal and axial gadolinium-enhanced T1-MRI imaging illustrates the spondylodiscitis mainly in segment C5/6 (star) with prevertebral (black arrow) and epidural abscesses (white arrows). c Gadolinium-enhanced T1-MRI imaging after 6 months demonstrates a completely decompressed spinal canal without any sign of a local infection. d Sagital CT images demonstrate the complete bony fusion of the involved level C5/6 1 year after monosegmental PEEK-cage spondylodesis. The stars mark the involved level C5/6. Again, there were no signs of neck pain, micro- or macroinstability in this patient

Fig. 4

Prerequisites for the preoperative evaluation of a ventral spondylodesis by a PEEK cage implantation in cervical spondylodiscitis. Patients who fulfill all criteria listed could be evaluated for insertion of a PEEK cage after microsurgical discectomy and spinal decompression, when their bony endplates of involved vertebrae are intact. Whenever one of the criteria is not given, the standard procedures with a ventral fixation system should be used