No abstract

Background:Anterior cervical discectomy with fusion is an effective treatment for patients having cervical radiculopathy and myelopathy. To reduce morbidity associated with autograft taken from the iliac crest without sacrificing high fusion rates, a novel technique that harvests bone from the vertebral body adjacent to the operative disc space has been proposed. The effects of square and round bone graft harvest techniques on the mechanical stability of the osteopenic donor vertebrae are unknown. We analyzed the biomechanical implications of the technique by subjecting osteopenic models to uniaxial compression to compare yield strengths of surgically altered and unaltered specimens.Methods:Biomechanical grade polyurethane foam was cut into 60 different 12 mm × 17 mm × 20 mm blocks. The foam had a density of 10 pounds per cubic foot, simulating osteoporotic bone. Rectangular prism (4 mm × 4 mm × 6 mm) and cylindrical cores (r = 2 mm, h = 8 mm) were removed from 20 blocks per group. Twenty samples were left intact as a control group. Anterior plate screws were applied to the models and a Polyether ether ketone (PEEK) interbody spacer was placed on top. Samples underwent uniaxial compression at 0.1 mm/s until mechanical failure. Points of structural failure were determined using a 0.1% offset on a force–displacement curve and compared to determine the reductions in compressive strength.Results:The mean force eliciting structural failure for intact samples was 450.6 N. Average failure forces for rectangular prisms and cylindrical cores removed were 383.2 and 395.4 N, respectively. Removal of a rectangular prismatic core of the necessary volume resulted in a 15.0% reduction in compressive strength, while removal of a cylindrical core of comparable volume facilitated a reduction of 12.2%.Conclusion:Local autograft harvested from adjacent vertebrae reduces morbidity associated with a second surgical site while minimally reducing the compressive strength of the donor vertebra in an osteopenic model, lending credence to the efficacy of this technique in elderly patient populations.

Study Design: Case series. Objectives: Successful clinical outcome scores following anterior cervical discectomy and fusion (ACDF) have been correlated with high fusion rate. Published fusion rates using iliac crest bone graft (ICBG) have been shown to be as high as 100% for single-level fusions in some studies; however, there is potential associated morbidity with ICBG harvest. This technical description and preliminary case series assessed the clinical efficacy and results of a novel grafting technique for ACDF. Methods: Twelve patients underwent novel grafting technique for ACDF in which autograft was procured from the cervical vertebra adjacent to the operative disk. Patients were followed for 2 years using visual analogue pain scale (VAS) and radiological assessment of fusion. Results: Patients experienced clinically meaningful reduction of radicular symptoms in the affected arm(s) with an average preoperative VAS score of 5.0 ± 0.8 and an average 2-year postoperative score of 1.108 ± 0.475 ( P = .0013). Patients also experienced significant resolution of neck pain with an average preoperative VAS score of 7.1 ± 0.5 and average 2-year postoperative score of 2.708 ± 0.861 ( P = .0018). All patients achieved solid fusion by 1 year. There were no major or minor complications noted during follow-up. Conclusions: This procedure allows for both autograft harvest and cervical decompression to be performed through a single incision. In this series, this technique eliminated the morbidity associated with autograft harvest from the iliac crest while achieving high fusion rates and without additional technique-related complications.