A novel unidirectional porous β-tricalcium phosphate grafting for vertebral fracture in the elderly: preliminary case series

Abstract

Objective: To treat vertebral fractures with posterior wall injury in the elderly, vertebral bone grafting is generally performed through a posterior transpedicular approach, combined with pedicle screw fixation. An autologous bone is ideal to treat this disorder. However, harvesting autologous bones from the elderly with osteoporosis is limited by the amount and quality of available autologous bone. Thus, we developed a bone-grafting substitute. The newly developed unidirectional porous β-tricalcium phosphate, with a porosity of 57% (UDPTCP; Affinos ® , Kuraray Co., Ltd., Tokyo, Japan), is used in the bone-grafting procedure. This is the first report of UDPTCP used as an artificial bone graft in patients with an acute vertebral burst fracture. Materials and Methods: UDPTCP (mean: 4.2 g) was implanted through the pedicle, and posterior instrumentation was achieved with pedicle screws in five elderly patients. Resorption of UDPTCP and substitution with the autologous bone were evaluated on computed tomography (CT) and plain X-ray performed immediately and at 3, 6, and 12 months after the operation. Results: In case 1, the pedicle screws did not loosen, and UDPTCP was completely resorbed and replaced with the autologous bone at 3 postoperative months. In the other four cases, although the pedicle screws or the caudal part loosened because of osteoporosis, resorption of UDPTCP was observed at 3 postoperative months. At 6 postoperative months, progressive substitution with the autologous bone was confirmed, and at 12 postoperative months, formation of the good autologous bone was confirmed. Conclusion: This preliminary case series demonstrated that the newly developed UDPTCP shows good clinical potential as a bonegraft substitute for acute vertebral burst fractures in the elderly, including patients with osteoporosis.

Use of Unidirectional Porous β-Tricalcium Phosphate in the Tibial Tunnel for Anterior Cruciate Ligament Reconstruction: A Case Series

“…Despite its β-TCP composition, the porosity and structure of UDPTCP ensure balanced bone formation and resorption, promoting early remodeling for sustained bone stability and functional recovery [7]. Moreover, the application of UDPTCP extends beyond the tibia, with successful outcomes in spinal surgeries and filling bone defects post-tumor excision reported previously [9][10][11][12]. These cases highlight the bone resorption capacity of UDPTCP starting within three months, with almost complete remodeling in six months to one year.…”

Clinical Outcomes of a Novel Unidirectional Porous β-Tricalcium Phosphate Filling in Distal Radius Fracture with Volar Locking Plate Fixation: Secondary Publication of the Japanese Version

“…Izawa et al [6] used Affinos ® in 4 cases of calcaneal fractures and reported that its resorption started at 3 months after surgery and replaced to host bone at 6 months in the earliest case. Funayama et al [7] used Afinos ® in 5 cases of burst vertebral fractures, showing that it was replaced to host bone at 3 months postoperatively in one case, and in other 4 cases, the resorption started at 3 months postoperatively and completed at 12 months. It suggested that Affinos has good properties of material resorption and replacement to host bone.…”

A clinical trial of a unidirectional porous tricalcium phosphate filling for defects after resection of benign bone lesions: a prospective multicenter study

“…Various studies have reported favorable outcomes with the use of β-TCP for bone defects. Despite only a small number of case reports being available, Affinos has been reported to be used successfully in clinical cases 11 – 13 . The present study also showed that Affinos maintains a balance between material resorption and trabeculation through the defect, resulting in stable clinical outcomes.…”