Hydroxyapatite/collagen composite graft for posterior lumbar interbody fusion: a comparison with local bone graft

Background Autologous bone has been used for posterior lumbar intervertebral fusion (PLIF). However, harvesting autologous bone graft is associated with donor site complications. We previously developed a hydroxyapatite/collagen (HAp/Col) composite as an osteoconductive artificial bone, characterized by having a highly porous structure with sponge‐like elasticity. This study aims to investigate the effectiveness of HAp/Col composite with bone marrow aspirate (BMA) as a graft substitute in PLIF for the treatment of lumbar spinal diseases. Methods This study prospectively investigated patients who received one-level PLIF. For the interbody fusion, two titanium cages were inserted. On the one side of interbody space, HAp/Col composite incorporated with BMA filling the titanium cage was grafted. On the other side, local bone graft (LBG) harvested during decompressive laminotomy was grafted and then one-level instrumentation using pedicle screws was performed. The target levels were at L2/3 in 2 cases, L3/4 in 3 cases, L4/5 in 36 cases, and L5/S in 5 cases. We evaluated clinical symptoms and radiological outcomes of 46 patients and compared the fusion status of HAp/Col composite with that of LBG. Results The 1-year postoperative CT evaluation demonstrated that, in the HAp/Col, a complete fusion was observed in 38 patients (82.6%), whereas in the LBG, a complete fusion was observed in 35 patients (76.1%). There were no statistical differences between the HAp/Col and LBG. In the HAp/Col, incomplete fusion was observed in five patients (10.9%) and non-fusion in two patients (4.3%), and in the LBG, incomplete fusion was observed in nine patients (19.6%) and non-fusion in two patients (4.3%). At 2 years after the surgery, complete fusion increased to 44 patients (95.7%) in the HAp/Col and 41 patients (89.1%) in the LBG. There were no significant differences in the clinical scores for lumbar spine between patients with fusion and non-fusion. Conclusions The HAp/Col composite with BMA in the titanium cage can be effectively used as an alternative to conventional autologous LBG for intervertebral spinal fusion. Trial registration University hospital Medical Information Network, UMIN000045010, July 30th, 2021, Retrospectively registered, https://www.umin.ac.jp/english/.

Titanium Cage in Comparison with Nano-Hydroxyapatite Bone Graft Substitutes in Cervical Reconstruction

Cervical spondylosis is a disease that occurs with age and affects the discs and joints in the cervical spine located in the neck. The hydroxyapatite (HA) bone graft substitutes can used as a potential bone-forming agent, however, the efficacy of using HA is challenging in cervical reconstruction. In this regard, nano-based HA was used in this study to explore its sagittal parameters and clinical potency in relative to titanium (TiO2) cage in patient with cervical spondylosis. 50 patients suffering from cervical spondylosis were divided in two groups and were grafted with either TiO2 cage or nano-HA. The sagittal parameters, including cervical spine lateral radiographs (C0−2Coob and C2−7Coob) were taken pre- and post-operation (3-month, one-year and two-year). The clinical potency was also done based on the JOA scores. Angle analysis indicated that the C0−2Cobb and C2−7Cobb angles were significantly changed after the operation in both TiO2 cage and nano-HA groups, whereas no significant changes was determined in nano-HA relative to TiO2 cage condition. Also, it was shown that JOA scores were significantly higher after the operation than pre-operation, indicating a potential cervical reconstruction after surgery in both groups which slightly were higher for nano-HA groups.

Vertebral Body Replacement With an Anchored Expandable Titanium Cage in the Cervical Spine: A Clinical and Radiological Evaluation

BACKGROUND Expandable cervical cages have been used successfully to reconstruct the anterior spinal column. OBJECTIVE To perform clinical and radiological evaluation of vertebral body replacement with an anchored expandable titanium cage in the cervical spine after single-level and 2-level corpectomies. METHODS Between 2011 and 2017, 40 patients underwent a single-level (N = 32) or 2-level (N = 8) anterior corpectomy and fusion using an anchored expandable vertebral body replacement cage. Clinical and radiological data at admission, postoperatively, and at 3- and 12-mo follow-up were retrospectively analyzed. Clinical assessment was performed via standardized neurological evaluation, Odom score, and McCormick classification. Radiological assessment was performed via evaluation of sagittal profile, postoperative position, fusion, and subsidence rates. RESULTS Mean last follow-up was 14.8 ± 7 mo. Overall clinical and myelopathy-related improvements were shown directly after operation and at last follow-up. A stable centralized positioning of cages was achieved in 37 patients (93%). A mild ventral (>1.5 mm) malplacement was noted in 3 patients (7%) without clinical consequences. Sagittal alignment and preoperative cervical kyphosis improved significantly (7.8° gain of lordosis) and remained stable. Mean preoperative height of operated segments increased by 10 mm postoperatively and remained stable. Fusion rate in non-neoplastic patients and subsidence rate at last follow-up comprised 87.5% and 17.8%. With exception of 1 patient suffering from severe osteoporosis and cage subsidence, no patient needed additional secondary stabilization. CONCLUSION Anterior corpectomy and fusion by an expandable anchored titanium cage with anchor screws without additional instrumentation resulted in overall clinical improvement and radiological anterior column support, achieving significant and reliable restoration of the physiological sagittal cervical profile.

Clinical Outcomes of 3D Printed Titanium Cage Implantation for Foot and Ankle Surgery

Category Ankle; Trauma Introduction/Purpose: Critical Sized Defects (CSD) defined as bone loss greater than 1-2 cm in length or greater than 50% loss in circumference of bone remains a significant challenge in orthopaedic surgery. Patients can acquire these defects through trauma, nonunion post fracture, tumor removal, avascular necrosis, and congenital abnormalities. Custom 3D printed porous Titanium scaffolds are increasingly being used to treat CSD in Foot and Ankle Surgery. Implantation of 3D printed cages is considered a salvage procedure offered after the patient has failed other procedures. Implants fill the space of the defect, provide mechanical strength and provide opportunity for osseous integration. As implementation of this surgical technique is relatively new, further research is needed to assess surgical outcomes and inform future surgical decision making. Methods: This is a retrospective chart review study which examines surgical outcomes after using 3D printed Titanium cages. Patients who received a 3D printed Titanium cage between 1/1/2013 and 11/01/2018 with at least 1 year follow-up were included in this study. Primary outcome is device failure defined as removal of implant for any reason. If applicable, mechanism of failure was recorded for each case. Patient specific factors such as age, gender, race, BMI, diabetes status, Charlson Comorbidity Index, tobacco use, number of foot and ankle surgeries, prior limb infections and laterality of defect were recorded in addition to surgical variables including geometry of implant, duration of surgery, and perioperative antibiotics Results: 18 patients who received custom 3D printed Titanium cages were included in this study. Of the 18 patients, 5 patients (27.8%) had device failure, defined as removal of implant. Of the 5 failures, 2 were removed due to infection while the other 3 were removed due to hardware failure including fractured cage, broken screw and loose fixation. Conclusion: Custom 3D printed Titanium was successfully implemented in 72.2% of patients. Implants were only removed due to infection (2 patients) or mechanical failure of device (3 patients). Future studies need to be powered to determine if certain patient specific factors are associated with device failure. Data from this study and subsequent studies can be used to design better implants, decide who is a good surgical candidate, and create preoperative therapies to improve modifiable risk factors