BACKGROUND:Modern imaging technology, computer-aided design and processing, rapid prototyping technology and other digital technology have enabled a new era of orthopedic field. Digitalization, individualization, minimal invasion, precision and intel igence are the potential topics in future orthopedics. ＜br> OBJECTIVE:To investigate clinical efficacy of computer-aided design of digital plate in the treatment of hip dislocations associated with posterior wal acetabular fracture. ＜br> METHODS:Sixteen patients of posterior wal acetabular fractures associated with hip dislocations were repaired with customized digital plate fixation. According to Thompson-Epstein fracture type:there were 7 cases with typeⅡ, 5 cases with type Ⅲ, 2 cases with type Ⅳ, and 2 cases with type Ⅴ. Radiographic examination showed the presence of 2-5 mm displacement on the acetabular articular surface, average 3 mm. The time from the injury to hospitalization was 6 hours to 2 weeks, average 1.5 days. After admission, patients underwent femoral condyle bone traction, 12 cases achieved a reduction and three cases of femoral head entrapment were reset during surgery. At 4-10 days after admission, al patients received computer-aided design of digital plate fixation for acetabular fractures. ＜br> RESULTS AND CONCLUSION:Postoperative fracture quality was assessed according to Matta standards, 15 cases had anatomical reduction (displacement＜1 mm) and 1 case had poor reduction (displacement 2-3 mm). The findings indicate that, computer-aided design of digital customized plate has achieved individualized and precise outcomes, as wel as firm fixation in the treatment of hip dislocations associated with posterior wal acetabular fracture. It avoids intraoperative repeated shaping, effectively restores the integrity of posterior wal , al ows early functional exercise, and provides alternative internal fixation for hip dislocations associated with posterior wal acetabular fracture.

Summary: The inhibitory effect of niacinamide on tumor necrosis factor-α (TNF-α) induced annulus fibrous (AF) degradation was assessed, and the mechanism of the inhibition was investigated. Chiba's intervertebral disc (IVD) culture model was established. Forty-eight IVDs from 12 adult Japanese white rabbits were randomly divided into 4 groups (12 IVDs in each group), and various concentrations of niacinamide and TNF-α were added to the medium for intervention: negative control group, niacinamide control group (0.5 mg/mL niacinamide), degeneration group (10 ng/mL TNF-α), and treatment group (0.5 mg/mL niacinamide and 10 ng/mL TNF-α). After one week's culture, AFs were collected for glycosaminoglycan (GS) content measurement, safranin O-fast green staining, and immunohistochemical staining for typeⅠ,Ⅱ collagen and cysteine containing aspartate specific protease-3 (Caspase-3). It was found that the GS content in treatment group was increased by about 48% as compared with degeneration group (t=16.93, P<0.001), and close to that in niacinamide control group (r=0.71, P=0.667). Safranine O-fast green staining exhibited higher staining density and better histological structure of AF in the treatment group as compared with the degeneration group. Immunohistochemical staining for both Type Ⅰ and Ⅱ collagen demonstrated that lameilar structure and continuity of collagen in treatment group were better reserved than in degeneration group. Positive staining rate of Caspase-3 in AFs of negative control group, niacinamide control group, degeneration group and treatment group was 3.4%, 4.3%, 17.9% and 10.3% respectively. The positive rate in treatment group was significantly lower than in degeneration group (P<0.01). It was concluded that niacinamide could effectively alleviate TNF-α induced destruction and synthesis inhibition of matrix ingredients in AFs. The inhibition may be related with reduction of expression of Caspase-3. Thus, niacinamide is of potential for IVD degeneration clinical treatment.