Pelvic reconstruction after sacral resection is challenging in terms of anatomical complexity, excessive loadbearing, and wide defects. Nevertheless, the technological development of 3D-printed implants enables us to overcome these difficulties. Here, we present a case of sacral osteosarcoma surgically treated with hemisacrectomy and sacral reconstruction using a 3D-printed implant. The implant was printed as a customized titanium prosthesis from a 3D real-sized reconstruction of a patient's CT images. It consisted mostly of a porous mesh and incorporated a dense strut. After 3-months of neoadjuvant chemotherapy, the patient underwent hemisacretomy with preservation of contralateral sacral nerves. The implant was anatomically installed on the defect and fixed with a screw-rod system up to the level of L3. Postoperative pain was significantly low and the patient recovered sufficiently to walk as early as 2 weeks postoperatively. The patient showed left-side foot drop only, without loss of sphincter function. In 1-year follow-up CT, excellent bony fusion was noticed. To our knowledge, this is the first report of a case of hemisacral reconstruction using a custom-made 3D-printed implant. We believe that this technique can be applied to spinal reconstructions after a partial or complete spondylectomy in a wide variety of spinal diseases.

There was no significant improvement in overall fusion rate and clinical outcome in our patients after injection of teriparatide, but the teriparatide group showed faster bony union and highly improved BMD scores.

The use of a cage with or without plate constructs in 2-level ACDF provides similar clinical results and fusion rates. Notwithstanding, ACDF-CPC showed a higher incidence of ASD than ACDF-CA over the 2-year follow-up.

Microsurgical bilateral decompression via a unilateral approach may be a good modality for treating round or oval shape spinal canal stenosis, but is not recommended for trefoil-shaped-stenosis. The current authors recommend performing the bilateral decompression technique in cases of trefoil-shaped-spinal canal stenosis.

HS is superior to 2-ACDF; it leads to better NDI recovery, less postoperative neck pain, faster C2-C7 ROM recovery, and less adjacent ROM increase over a 2-year follow-up, but these benefits of HS become similar to those of 2-ACDF with 5 years of follow-up.