DIAM Implantation for Degenerative Disc Disease
Authors: Lu K. 
Published: May 2014

Introduction Lumbar disc degeneration (LDD) is among the most common causes of low back pain. Typical symptoms include axial low back pain, buttock pain, with or without radiation to posterior thighs or legs, and intolerance to upright positions. Several surgical treatment options are available, including intradiscal injections, intradiscal electrothermal therapy, discectomy, total disc arthroplasty, and fusion. Recently, implantation of interspinous process devices has been shown to decrease low back pain, and provide morphological alterations of the degenerative discs, resulting in satisfactory clinical outcomes. This study was conducted to review our results of using stand-alone DIAM implantation as the treatment for symptomatic LDD. Materials and Methods A total of 24 selected cases of LDD were treated surgically with stand-alone DIAM implantation. In 20 patients, the presenting symptoms were predominantly axial low back/buttock pain with little leg pain, while in 4 patients there was only axial pain. Motor weakness and sensory disturbance involving the corresponding nerve roots were present in eight cases. Three patients had undergone previous lumbar discectomy of the afflicted discs. Typical MRI findings included loss of height, signal changes, and/or annular tear of the discs. On the basis of Pfirrmann grading scale for disc degeneration, three cases were categorized as Grade II, and 21 cases as Grade III. Our exclusion criteria included intermittent claudication due to lumbar spinal stenosis, severe disc space collapse with Modic changes, greater than Grade II spondylolisthesis, facet ankylosis, and L5-S1 pathology. Provocative test with intradiscal injection of normal saline-induced concordant pain in all cases. Results All patients reported significant symptom relief after surgery, as reflected by VAS and ODI improvements. The final outcomes were excellent in 19, good in 2, fair in 2, and poor in 1 cases. Segmental flexion/extension mobility was maintained in 20, and restricted or lost in 2, of 22 cases with preoperative mobility. In the other two cases with no preoperative mobility, DIAM implantation did not change the status. MRI was repeated in the two cases showing fair, and the one case showing poor outcomes. In all of them, enlargement of neuroforamens at the implanted levels were found. In one fair case, disappearance of annular tear was observed. In the other fair case (L4-5 implantation), L5-S1 disc herniation was disclosed, and removed in a second operation. The case with poor outcome was diagnosed with depression, having concomitant multiple joint pain, dysmenorrhea, sleep disorder, despite normal findings on different exams ordered by different specialists. Conclusion In highly selected cases with symptomatic LDD, stand-alone interspinous DIAM implantation is effective for alleviation of symptoms, and stabilization of disc status. Disclosure of Interest None declared References Sandu N, Schaller B, Arasho B, Orabi M. Wallis interspinous implantation to treat degenerative spinal disease: description of the method and case series. Expert Rev Neurother 2011;11(6):799–807 Buric J, Pulidori M, Sinan T, Mehraj S. DIAM device for low back pain in degenerative disc disease : 24 months follow-up. Acta Neurochir Suppl (Wien) 2011;108:177–182 Pfirrmann CW, Metzdorf A, Zanetti M, Hodler J, Boos N. Magnetic resonance classification of lumbar intervertebral disc degeneration. Spine 2001;26(17):1873–1878