Comparison of Union Rates Between Autogenous Iliac Crest Bone Graft and Local Bone Graft as Fusion Materials in Lumbar Fusion Surgery: An Evaluation of Up to 3-Level Fusion

Osteobiologies for Spinal Fusion from Biological Mechanisms to Clinical Applications: A Narrative Review

Degenerative lumbar spinal disease (DLSD), including spondylolisthesis and spinal stenosis, is increasing due to the aging population. Along with the disease severity, lumbar interbody fusion (LIF) is a mainstay of surgical treatment through decompression, the restoration of intervertebral heights, and the stabilization of motion segments. Currently, pseudoarthrosis after LIF is an important and unsolved issue, which is closely related to osteobiologies. Of the many signaling pathways, the bone morphogenetic protein (BMP) signaling pathway contributes to osteoblast differentiation, which is generally regulated by SMAD proteins as common in the TGF-β superfamily. BMP-2 and -4 are also inter-connected with Wnt/β-catenin, Notch, and FGF signaling pathways. With the potent potential for osteoinduction in BMP-2 and -4, the combination of allogenous bone and recombinant human BMPs (rhBMPs) is currently an ideal fusion material, which has equalized or improved fusion rates compared to traditional materials. However, safety issues in the dosage of BMP remain, so overcoming current limitations will provide significant advancement in spine surgery. In the future, translational research and the application of clinical study will be important to overcome the current limitations of spinal surgery.

Application of nano-hydroxyapatite matrix graft in inter-vertebral fusion therapy: a meta-analysis

OBJECTIVE

Nano-hydroxyapatite and its composites(nHA) have been widely used as grafts in inter-vertebral fusion. However, the safety and efficacy of the graft in inter-vertebral fusion is controversial. This meta-analysis aimed at evaluating the safety and efficacy of nHA and non-hydroxyapatite grafts (noHA) (autologous bone, etc.) in inter-body fusion.

MATERIALS AND METHODS

A comprehensive search was performed in electronic database as follows: PubMed, EMBASE, the Cochrane Library, Web of Science, and China National Knowledge Internet (CNKI) from inception until October 2022. Clinical studies on the effect of nHA and noHA in spinal fusion were collected. Analysis of outcome indicators using RevMan 5.4 statistical software.

RESULTS

The meta-analysis showed that the operation time of patients who underwent inter-body fusion with nHA grafts was less than that of patients who underwent noHA (p < 0.05). Compared with the noHA group, the nHA group can achieve similar clinical effects in the fusion rate(OR = 1.29,95%CI: 0.88 to 1.88,p = 0.19),Subsidence rate(OR = 1.2,95%CI:0.44 to 3.28,p = 0.72), inter-vertebral space height(SMD = 0.04,95%CI:-0.08 to 0.15,p = 0.54),Cobb angle(SMD = 0.21,95%CI: 0.18 to 0.6,p = 0.21),Blood loss(SMD = -36.58,95%CI: -81.45 to 8.29,p = 0.11),operative time in 12 months(SMD = -5.82,95%CI: -9.98 to -1.67,p = 0.006) and in the final follow-up(SMD = -0.38,95%CI: -0.51 to -0.26,p < 0.00001),ODI(SMD = 0.68,95%CI: -0.84 to 2.19,p = 0.38), VAS(SMD = 0.17,95%CI: -0.13 to 0.48,p = 0.27) and adverse events(OR = 0.98,95%CI: 0.66 to 1.45,p = 0.92), and the differences are not statistically significant.

CONCLUSION

This meta-analysis suggests that nHA matrix grafts are similar to noHA grafts in the safety and efficacy of spinal reconstruction, and are an ideal material for inter-vertebral bone grafting.

Continuously released Zn2+ in 3D-printed PLGA/β-TCP/Zn scaffolds for bone defect repair by improving osteoinductive and anti-inflammatory properties

Long-term nonunion of bone defects has always been a major problem in orthopedic treatment. Artificial bone graft materials such as Poly (lactic-co-glycolic acid)/β-tricalcium phosphate (PLGA/β-TCP) scaffolds are expected to solve this problem due to their suitable degradation rate and good osteoconductivity. However, insufficient mechanical properties, lack of osteoinductivity and infections after implanted limit its large-scale clinical application. Hence, we proposed a novel bone repair bioscaffold by adding zinc submicron particles to PLGA/β-TCP using low temperature rapid prototyping 3D printing technology. We first screened the scaffolds with 1 wt% Zn that had good biocompatibility and could stably release a safe dose of zinc ions within 16 weeks to ensure long-term non-toxicity. As designed, the scaffold had a multi-level porous structure of biomimetic cancellous bone, and the Young's modulus (63.41 ± 1.89 MPa) and compressive strength (2.887 ± 0.025 MPa) of the scaffold were close to those of cancellous bone. In addition, after a series of in vitro and in vivo experiments, the scaffolds proved to have no adverse effects on the viability of BMSCs and promoted their adhesion and osteogenic differentiation, as well as exhibiting higher osteogenic and anti-inflammatory properties than PLGA/β-TCP scaffold without zinc particles. We also found that this osteogenic and anti-inflammatory effect might be related to Wnt/β-catenin, P38 MAPK and NFkB pathways. This study lay a foundation for the follow-up study of bone regeneration mechanism of Zn-containing biomaterials. We envision that this scaffold may become a new strategy for clinical treatment of bone defects.

Efficacy of NHP66 Bioactive Cage on Patients with Cervical Spine Injury in Short-Track Speed Skating

Background

Short-track speed skating (STSS) is an extreme sport in pursuit of extreme speed and explosive force. In such a sport, once athletes fall down, they are susceptible to serious cervical spine injury (CSI) under the inertia of high-velocity movement. Nanohydroxyapatite/polyamide 66 (NHP66) bioactive cage is a high-tech product of nanotechnology in the medical field in recent years. With a structure similar to that of human cortical bone, NHP66 bioactive cage has extremely high toughness and strength, which tailors to the needs of STSS.

Objective

This study mainly analyzed the therapeutic effect of NHP66 on patients with CSI in STSS, aiming to provide new opportunities for the treatment of this patient population.

Methods

A total of 51 patients with CSI treated in our hospital were enrolled, including 19 cases of short-track speed skaters (observation group) and 32 cases of car accidents, falls from heights, or collision injuries (control group). The relevant surgical indicators (operation time, intraoperative blood loss, etc.), the incidence of adverse reactions, the Cobb angle of cervical lordosis before and after surgery, and the fusion segment height of the cage were observed and compared between the two groups. Postoperative pain was evaluated by the visual analog scale (VAS), improvement of spinal cord injury was assessed by the American Spinal Cord Injury Association (ASIA) Impairment Scale, and bone fusion, bone subsidence, and other motor functions were assessed by the Japanese Orthopaedic Association (JOA) score rating system.

Results

The operation time, intraoperative blood loss, and incidence of adverse reactions in the observation group were significantly lower than those in the control group. The Cobb angle of cervical lordosis and the fusion segment height of cage increased significantly higher in both groups after surgery. In addition, the VAS scores of the observation group 2 h and 3 d after operation were significantly lower than those of the control group. In terms of improvement of spinal cord injury, ASIA and JOA scores in the observation group were significantly higher than those before treatment and in the control group. There was no significant difference in bone fusion activity between the two groups.

Conclusions

In this study, it is found through experiments that NHP66 has higher safety and application value than autogenous iliac bone, confirming that NHP66 can achieve significant results as a cage for anterior cervical decompression and iliac bone graft fusion and internal fixation in short-track speed skaters after CSI.

Clinical and radiographic outcomes of hybrid graft in patients with Modic changes undergoing transforaminal lumbar interbody fusion

Background

This retrospective study aimed to analyze the influence of Modic changes (MCs) on the clinical and radiographic outcomes of transforaminal lumbar interbody fusion with hybrid graft.

Methods

Clinical data of 89 patients with Modic changes who underwent single-segment transforaminal lumbar interbody fusion between January 2015 and January 2019 at our institution were analyzed. Patients were divided into three groups: the MCs-0 group (no endplate changes; used as the control group), the MCs-1 group, and the MCs-2 group. Clinical and radiological parameters were compared between the three groups.

Results

There were no significant between-group differences in age (P = 0.216), sex (P = 0.903), body mass index (P = 0.805), smoking (P = 0.722), diagnosis (P = 0.758), surgical level (P = 0.760), blood loss (P = 0.172), operative time (P = 0.236), or follow-up (P = 0.372). Serum C-reactive protein level and erythrocyte sedimentation rate in the MCs-1 and MCs-2 groups were significantly higher than those in the MCs-0 group on the third and seventh days (P < 0.05). Postoperative radiographic parameters were significantly higher than preoperative parameters in all 3 groups (P < 0.05). Visual analog scale scores for low back pain in the MCs-0 and MCs-2 groups were significantly different from those in the MCs-1 group (P < 0.05). However, there were no significant between-group differences with respect to Oswestry Disability Index scores or visual analog scale scores for leg pain.

Conclusion

In this study, Modic changes had no impact on fusion rates and clinical outcomes of transforaminal lumbar interbody fusion with hybrid graft (autologous local bone graft plus allogeneic freeze-dried bone graft). However, MCs-1 increased the risk of cage subsidence and showed superior outcomes in terms of visual analog scale scores for low back pain.