Locking compression plate distal ulna hook plate fixation versus intramedullary screw fixation for displaced avulsion fifth Metatarsal Base fractures: a comparative retrospective cohort study.

BACKGROUND: Intramedullary screw (IMS) fixation was wildly used in fifth metatarsal base fractures (FMBFs) and the results were satisfactory. However, in the comminuted osteoporosis or small displaced avulsion FMBFs, anatomical reduction and stable fixation could not be achieved with IMS. The Locking Compression Plate (LCP) distal ulna hook plate fixation was a novel alternative fixation method. The aim of this retrospective cohort study was to determine if LCP distal ulna hook plate fixation resulted in improved outcomes compared to the traditional IMS fixation in displaced avulsion FMBFs. METHODS: Of 43 patients with displaced avulsion FMBFs, 18 patients were treated with LCP distal ulna hook plate fixation and 25 were treated with IMS fixation. The patients were evaluated clinically and radiographically and followed up to 12 months. The surgery time, time for hospital stay, time for weight-bearing, time for bony union, time for return to daily life, pain relief, functional outcome and complications after treatment with LCP distal ulna hook plate fixation or IMS fixation were compared. The functional outcome was assessed by the AOFAS (American Orthopedic Foot and Ankle Society) mid-foot score at 3, 6, 9, and 12 months after surgery. Meanwhile, pain scores were obtained at 3, 6, 9, and 12 months after surgery. RESULTS: The two cohorts had similar baseline characteristics. Surgery time was less in LCP distal ulna hook plate fixation cohort compare to IMS fixation cohort (p < 0.0001). Time for partial weight-bearing (p < 0.0001) and full weight-bearing (p < 0.0001) also demonstrated significant improvements in patients with LCP distal ulna hook plate fixation compared to IMS fixation. Patients in the LCP distal ulna hook plate fixation cohort had significantly increased AOFAS at 9 months (p < 0.0001) and 12 months (p < 0.0001) after surgery compared to the IMS fixation cohort. CONCLUSION: In this retrospective cohort study, LCP distal ulna hook plate fixation as an alternative fixation method was better therapy for the displaced avulsion FMBFs compared to IMS fixation. LCP distal ulna hook plate fixation had a short surgery time and improved functional performance.

Manipulation of visible-light polarization with dendritic cell-cluster metasurfaces.

Cross-polarization conversion plays an important role in visible light manipulation. Metasurface with asymmetric structure can be used to achieve polarization conversion of linearly polarized light. Based on this, we design a quasi-periodic dendritic metasurface model composed of asymmetric dendritic cells. The simulation indicates that the asymmetric dendritic structure can vertically rotate the polarization direction of the linear polarization wave in visible light. Silver dendritic cell-cluster metasurface samples were prepared by the bottom-up electrochemical deposition. It experimentally proved that they could realize the cross - polarization conversion in visible light. Cross-polarized propagating light is deflected into anomalous refraction channels. Dendritic cell-cluster metasurface with asymmetric quasi-periodic structure conveys significance in cross-polarization conversion research and features extensive practical application prospect and development potential.

Current concepts in the treatment of gouty arthritis.

Gouty arthritis is an extremely painful condition that causes functional impairment. Gouty arthritis has become increasingly complex because of multiple comorbidities, iatrogenic factors and hyperuricemia that is refractory to treatment. In this review, we present a general overview of gouty arthritis including its pathophysiology, clinical presentations, diagnosis, predisposing factors and prophylactic therapy for preventing gouty arthritis flares.

[Clinical investigation of the minimal invasive osteotomy for the treatment of hallux valgus combined with tailor's bunion].

OBJECTIVE: To investigate the clinical effects of the minimal invasive osteotomy treatment for hallux valgus combined with tailor's bunion deformity. METHODS: From May 2007 to May 2009, Forty-nine feet of 32 patients (a mean age of 57 years old) of hallux valgus combined with tailor's bunion deformity were reviewed retrospectively, including 2 males(2 feet) and 30 females (47 feet). All patients were treated by the minimal invasive osteotomy. The axial and lateral films of all feet with loading were taken before and after operation. The hallux abducto valgus angle(HAV),intermetatarsal angle(IM), fourth-fifth intermetatarsal angle (IM 4 to 5), modified fourth-fifth intermetatarsal angle (MIM 4 to 5), Metatarsophalangeal-fifth angle (MPA) and lateral deviation of the fifth matatarsal angle (LDA) were compared before and after operation. Therapeutic effects of all the patients were observed after operation, the item including AFAS score and WEN Jian-min's therapeutic effects standard. RESULTS: The average operating time was 40 minutes. All the patients were followed up,and the duration ranged from 6 to 24 months. The HAV angle, IM angle, IM 4 to 5 angle, MIM 4 to 5 angle,MPA angle and LDA angle significantly decreased after operation. The AFAS score significantly raised after operation. According to the criteria, 33 feet got an excellent result, 15 good and 1 fair. CONCLUSION: The minimal invasive osteotomy treatment for hallux valgus combined with tailor's bunion is effective and safe. This method is mini-trauma,less pain and it can make a very soon rehabilitation. This method has widely clinical value.

[Experiment study of alendronate in the prevention and treatment of aseptic loosening of prosthesis].

OBJECTIVE: To investigate the effect of alendronate on the prevention and treatment of aseptic loosening of prosthesis. METHODS: A rat model of particle-induced osteolysis was used. Thirty-xis SD rats were divided into three groups: negative control group, positive control group and experiment group. Alendronate was administered by ig in experiment group. Positive control group and experiment group received intro-articular injections of ultrahigh molecular weight polyethylene (UHMWPE) particles at 4, 6, 8, 10 weeks postoperatively. Negative control group was received injection with mixture solution of mouse serum and PBS only. All animals were sacrificed at 12 weeks after operation for histologic examination. In vitro human peripheral blood mononuclear (PBMC)were separated and cultured and divided into five groups as group A: PBMC group, group B: PBMC and particles,group C:PBMC and particles with 10(-4) mol/L alendronate, group D:PBMC and particles with 10(-5) mol/L alendronate, group E: PBMC and particles with 10(-6) mol/L alendronate. The production of IL-1beta, IL-6, TNF-alpha in each group were tested. RESULTS: Alendronate could prevent particle-induced osteolysis. The production of IL-1beta, IL-6, TNF-alpha was inhibited when alendronate was used. CONCLUSION: Alendronate can inhibit bone absorptive factors expression induced by wear particles and may be used in the prevention and treatment of aseptic loosening of prosthesis.