Poly(methyl methacrylate) bone cement composited with mineralized collagen for osteoporotic vertebral compression fractures in extremely old patients

To examine the clinical effects of a new bone cement composed of poly(methyl methacrylate)(PMMA)and mineralized collagen(MC)compared with pure PMMA bone cement in treating osteoporotic vertebral compression fractures(OVCFs)in patients aged over 80.In all,32 cases using pure PMMA bone cement and 31 cases using MC-modified PMMA(MC-PMMA)bone cement for OVCFs between June 2014 and March 2016 were screened as PMMA group and MC-PMMA group,respectively,with an average age of over 80.The operation duration,intraoperative blood loss,hospital stay,oswestry disability index(ODI),visual analogue scale(VAS),anterior vertebral height(AVH),intermediate vertebral height(IVH)and posterior vertebral height(PVH)of injured vertebrae,vertebral computed tomography value,re-fracture rate of adjacent vertebrae,correction rate of spinal kyphotic angle and wedge-shaped vertebra angle and surgical complications were compared between the two groups.In the early post-operative period,the VAS,ODI,AVH and IVH in MC-PMMA group were comparable to those in the traditional PMMA group.Moreover,the MC-PMMA group showed better effects compared with the PMMA group 12months after surgery.Thus,this new bone cement has superior clinic effects in the long term.

Aligned fibrin/functionalized self-assembling peptide interpenetrating nanofiber hydrogel presenting multi-cues promotes peripheral nerve functional recovery

Nerve guidance conduits with hollow lumen fail to regenerate critical-sized peripheral nerve defects(15 mm in rats and 25 mm in humans),which can be improved by a beneficial intraluminal microenvironment.However,individual cues provided by intraluminal filling materials are inadequate to eliminate the functional gap between regenerated nerves and normal nerves.Herein,an aligned fibrin/functionalized self-assembling peptide(AFG/fSAP)interpenetrating nanofiber hydrogel that exerting synergistic topographical and biochemical cues for peripheral nerve regeneration is constructed via electrospinning and molecular self-assembly.The hydrogel possesses an aligned structure,high water content,appropriate mechanical properties and suitable biodegradation capabilities for nerve repair,which enhances the alignment and neurotrophin secretion of primary Schwann cells(SCs)in vitro,and successfully bridges a 15-mm sciatic nerve gap in rats in vivo.The rats transplanted with the AFG/fSAP hydrogel exhibit satisfactory morphological and functional recovery in myelinated nerve fibers and innervated muscles.The motor function recovery facilitated by the AFG/fSAP hydrogel is comparable with that of autografts.Moreover,the AFG/fSAP hydrogel upregulates the regeneration-associated gene expression and activates the PI3K/Akt and MAPK signaling pathways in the regenerated nerve.Altogether,the AFG/fSAP hydrogel represents a promising approach for peripheral nerve repair through an integration of structural guidance and biochemical stimulation.

Modified poly(methyl methacrylate) bone cement in the treatment of Kümmell disease

Kuümmell disease(KD)causes serious vertebral body collapse in patients.However,only a few case reports have been conducted and the number of patients with KD investigated was limited.Additionally,the frequently used poly(methyl methacrylate)(PMMA)bone cement for KD is limited by excessive modulus and poor biocompatibility.Herein,we aimed to modify PMMA bone cement with mineralized collagen(MC),and compare the clinical effects,image performance and finite ele-ment analysis between the modified bone cement and PMMA bone cement for the treatment of phase I and II KD.Thirty-nine KD patients treated with PMMA bone cement and 40 KD patients treated with MC-modified PMMA bone cement from June 2015 to March 2017 were retrospectively analyzed.The surgical procedure,intraoperative blood loss,hospital stay and complications were compared between different groups.Visual analog scale,Oswestry disability index,anterior verte-bral height,posterior vertebral height,computed tomography value,adjacent vertebral re-fracture,Cobb angle and wedge-shaped correction angle were evaluated.Additionally,the representative sample was selected for finite element analysis.We found that the MC-modified PMMA bone ce-ment could achieve the same effect as that of PMMA bone cement and was associated with better vertebral height restoration in the long term.