Follow-up Study on the Motion Range after Treatment of Degenerative Disc Disease with the Bryan Cervical Disc Prosthesis

This study examined effect of a new intervertebral cervical disc prosthesis in relieving the neurological symptoms and signs, improving the patients＇ ability to perform daily activities, reducing pain, and maintaining the stability and segmental motion. From December 2003 to October 2004, 12 patients, who had received 14 replacements of cervical artificial discs, were followed-up for 2 to 8 months （with a mean of 5.2 months）. Of them 5 had cervical spondylotic myelopathy and 7 had cervical disc herniation. The patients included 7 males and 5 females, with their age ranging from 35 to 62 y and a mean of 50.3 y. Single-level replacements were performed in 10 cases and 2 cases received two-level replacement. Operation time of the single-level surgery averaged 130±50 rain and the time of two-level surgery was 165±53 min on average （from skin incision to skin suturing）. Neurological or vascular complications during or after surgery was not observed. Japanese Orthopedic Association scores （JOA scores） increased from 8.6 to 15.8 on average. There was no prothesis subsidence or excursion. Replaced segments were stable and the range of motion was partially restored, being 4.68° （3.6°-6.1°） in flexion and extension position and 3.51 ° （2.5°-4.6°）, 3.42° （2.6°-4.3°） in left and right bending position. No obvious loss of physiological curvature was noted. CT or MRI follow-up showed that excursion was less than 1.5 mm） in 2 of 14 levels and between 1.5 mm and 3 mm） in 1 of 14 levels. No ossification in the replaced levels was observed. It is concluded that satisfactory short-term results were achieved in the 12 cases of artificial disc replacements. Different from anterior cervical discectomy and fusion, the replacement could achieve quick functional recovery and did not lead to the movement limitation of cervical vertebrae. At least a 5-years follow-up was needed to assess the long-term effect of the prosthesis on its neighboring segments.

Macrophage-derived exosomes modulate wear particle-induced osteolysis via miR-3470b targeting TAB3/NF-κB signaling

Aseptic prosthesis loosening(APL)is one of the most prevalent complications associated with arthroplasty.The main cause is the periprosthetic osteolysis induced by wear particles.However,the specific mechanisms of crosstalk between immune cells and osteoclasts/osteoblasts during osteolysis are unclear.In this study,we report the role and mechanism of macrophage-derived exosomes in wear particle-induced osteolysis.The results of exosomes up-taken experiments revealed that osteoblast and mature osteoclasts capture macrophage-derived exosomes(M-Exo).Next-generation sequencing and RT-qPCR on M-Exo revealed that exosomal microRNA miR-3470b was downregulated in wear particle-induced osteolysis.The results of analysis on Luciferase reporter assays/fluorescence in situ hybridization(FISH)/immunofluorescence(IF)/immunohistochemistry(IHC)and co-culture experiments demonstrated that wear particles induced osteoclast differentiation by increasing the expression of NFatc1 via M-Exo miR-3470b targeting TAB3/NF-κB signaling.We also illustrate that engineered exosomes enriching miR-3470b facilitated to suppressed the osteolysis;the microenvironment enriching with miR-3470b could suppress wear particle-induced osteolysis via inhibition of TAB3/NF-κB in vivo.In summary,our findings indicate that macrophage-derived exosomes transfer to osteoclasts to induce osteolysis in wear particle-induced APL.Engineering exosomes enriching with miR-3470b might be a novel strategy for the targeting treatment of bone resorption-related diseases.