The effect of radial head replacement on terrible triad of elbow / 中华骨科杂志

Objective To observe the short-term effect of radial head replacement for the treatment of terrible triad of the elbow.Methods In the period between June 2011 and June 2012,the radial head replacements were carried out in six patients with terrible triad of elbow.There were five acute elbow fracture-dislocation cases and one old fractnre case.All cases underwent open reduction and fixation coronoid fracture with screws or nonabsorbable sutures,radial head replacement,repair of lateral ligament complex and repair or reconstruction of annular ligament.All patients initiated the rehabilitation program under supervision within 5-7 days after surgery.The X-ray and Computed tomography of elbow was used to evaluate the posi tion of radial head prosthesis.Functional outcome of elbow was assessed by Mayo Elbow Performance Score (MEPS) and complications.Results All patients were participated in follow-up for 10-24 months and the mean duration of follow-up was 16.8 months.The MEPS was from 85 to 95 points and the mean MEPS was 91.7 points.The outcome of MEPS was excellent in 5 cases,good in 1 case.The range motion of elbow flexion was from 82 to 95 degrees and the average of elbow flexion was 87 degrees; the range motion of extension was from 15 to 32 degrees and the average of elbow extension was 21 degrees.The range motion of fore-ann pronation was from 82 to 90 degrees with 86 degrees in average.The motion range of supination was from 45 to 80 degrees with 56 degrees in average.All cases got persistent stability in elbow with painless movement.None of patient suffered traumatic arthritis and infection.The motion range of elbow was restricted due to the unfit relative position of radial head prosthesis and capi tellum in one case,characterized by decreasing radiocapitellar joint space.Two cases developed into heterotopic ossification in elbow without hampering the motion range of elbow.Conclusion The outcome of the radial head replacement on the treatment of radial head fracture in the elbow terrible triad was satisfactory.However,the longer duration of observation was essential to verify the favorable effect of radial head replacement on dealing with terrible triad in elbow.

Effect of alendronate amount on the static mechanical properties of bone cement / 中南大学学报(医学版)

OBJECTIVE@#To determine the effect of alendronate amount on the static mechanical properties of bone cement before elution and 4 weeks after elution, and determine suitable amount of alendronate in cement from the perspective of biomechanics.@*METHODS@#Samples of compression strength and bending strength (modulus) were prepared with bone cement adding 0, 10, 50, 100, 500 and 1000 mg alendronate in 50 g Cemex®XL bone cement powders respectively (named as G0-G5 groups). The compression strength, bending strength, and bending modulus of bone cement were examinated by INSTRON 8032 tester before the elution and 4 weeks after the elution. Some broken samples of 4-point bending test were examinated by scanning electronic microscopy (SEM), and some other samples of bending strength (modulus) tests by micro-CT.@*RESULTS@#No significant difference was found in the compression strength before the elution,4 weeks after elution in the 6 groups, and before and after the elution in the respective groups (P>0.05). Compared with G0 group, G1-G4 groups had no obvious difference in the bending strength before the elution and 4 weeks after the elution (P>0.05), while G5 group had difference (P0.05). Taken G0 group as the control group, G1-G4 groups had no visible effects on the bending modulus 4 weeks after the elution (P>0.05), while G5 group decreased it significantly (P0.05), while bending modulus before and after the elution in the respective groups displayed a marked difference (P<0.05).@*CONCLUSION@#Less than 500 mg alendronate added in Cemex?XL 50 g bone cement powder does not decrease the compressive strength, flexural strength and flexural modulus before the elution and 4 weeks after the elution.

Effect of alendronate-loaded bone cement on osteoblast / 中南大学学报(医学版)

OBJECTIVE@#To determine the effect of bone cement, with different amounts of alendronate on osteoblast, and determine the cytotoxicity of alendronate-integrated bone cement from the viewpoint of cell biology.@*METHODS@#According to different additions (0, 10, 50, 100, 500, 1 000 mg) of alendronate in 50 g Cemex®XL bone cement powder, the experiments were divided into 6 groups, namely G0-G5 groups. In all groups, the adhesive capacity of osteoblast-like cells MG-63 was evaluated by electron microscope, the optical density (OD) value of cells by MTT colorimetry method, the alkaline phosphatase activity (AKP) by AKP assay kit, the apoptosis rates by Annexin-V-FITC apoptosis detection kit, and the bone mineralization potentiality by phase contrast microscope.@*RESULTS@#The adhesive capacity of MG-63 was good in all groups. Compared with the G0 group, the cell apoptosis was inhibited in G1-G4 groups while in G5 group the cell apoptosis was promoted and cell proliferation was inhibited (P0.05).@*CONCLUSION@#Less than 500 mg alendronate added in Cemex®XL 50 g bone cement powder has no cytotoxicity on osteoblasts.