A new low-profile anatomic locking plate for fixation of comminuted, displaced greater tuberosity fractures of the proximal humerus.

BACKGROUND: Although various implants exist for the fixation of isolated greater tuberosity fractures, few implants are specifically designed for such fractures. The purpose of this study was to investigate the clinical and radiologic outcomes of open reduction-internal fixation with a low-profile anatomic locking plate for comminuted greater tuberosity fractures of the proximal humerus. METHODS: From November 2012 to February 2018, 24 patients with displaced and comminuted isolated greater tuberosity fractures were treated with the new low-profile anatomic locking plate. To determine clinical outcomes, we evaluated active range of motion; the visual analog scale pain score; the Constant-Murley score; the Disabilities of the Arm, Shoulder and Hand score; radiographs; and complications. RESULTS: In all cases, a mean follow-up period of 29.3 months (range, 18-48 months) was completed. All patients achieved bone union with a mean healing time of 11.3 weeks (range, 8-16 weeks). The mean Constant-Murley score was 91.1 points (range, 69-100 points), with a rate of good to excellent results of 95.8%. The average Disabilities of the Arm, Shoulder and Hand score was 9.9 points (range, 2-25 points), and the mean visual analog scale pain score was 1.1 points (range, 0-4 points). Mean active forward flexion, abduction, external rotation, and internal rotation (level) were 157°, 152°, and 40°, and T11, respectively. Postoperatively, 1 patient had persistent shoulder stiffness, and 1 patient had recurrence of shoulder dislocation because of a falling injury during badminton. No serious complications such as subacromial impingement, malunion, nonunion, loss of reduction, or implant failure occurred. CONCLUSIONS: The new low-profile anatomic locking plate was useful for the treatment of comminuted isolated greater tuberosity fractures as it provided reliable stability and satisfactory radiographic and functional results. The described technique is a simple and effective method and provides a new reliable option for the treatment of isolated greater tuberosity fractures.

Effects of Simvastatin and Combination of Simvastatin and Nylestriol on Bone Metabolism in Ovariectomized Rats.

We aim to compare the effects of simvastatin and combination of simvastatin and nylestriol on bone metabolism in ovariectomized (OVX) rats. Fifty healthy Wistar female rats were randomly allocated into 5 groups: sham + saline group (group A), OVX + saline group (group B), OVX + simvastatin (5 mg·kg·d) (group C), OVX + nylestriol (0.01 mg·kg·d) (group D), and OVX + simvastatin (3 mg·kg·d) + nylestriol (0.005 mg·kg·d) (group E). All mice were orally administrated with saline or medicine dissolved in saline for 10 weeks. Body weight of rats before and after the experiment was measured. Twenty-four hours after the experiment, calcium (Ca), creatinine (Cr), and hydroxyproline in urine were detected. Serum levels of osteocalcin (bone Gla-protein, BGP) and alkaline phosphatase (ALP) were measured. Bone mineral density was detected and trabecular bone was observed after the isolation of femur and tibia. Remarkably decreased serum BGP and increased serum ALP levels were detected in group B compared with those in group A. However, notably increased serum BGP and decreased serum ALP levels were found in groups C, D, and E compared with those in group B; femoral and tibial bone mineral density decreased in group B compared with that in group A, but increased in groups C, D, and E compared with that in group B. Simvastatin and combination of simvastatin and nylestriol promote formation of new bone, increase bone density, and improve bone microstructure damage in OVX rats.

Preparation and characterization of a novel injectable strontium-containing calcium phosphate cement with collagen.

PURPOSE: To develop a novel injectable strontium-containing calcium phosphate cement with collagen. METHODS: A novel calcium phosphate bone cement (CPC) was prepared with the addition of strontium element, collagenl, and modified starch; the injectability, solidification time, microstructure, phase composition, compressive strength, anti-collapsibility and histological properties of material were evaluated. RESULTS: The results showed that the material could be injected with an excellent performance; the modified starch significantly improved the anti-washout property of cement; with the liquid to solid ratio of 0.3, the largest compressive strength of cement was obtained (48.0 MPa ± 2.3 MPa); histological examination of repair tissue showed that the bone was repaired after 16 weeks; the degradation of cement was consistent with the new bone growth. CONCLUSION: A novel injectable collagen-strontium-containing CPC with excellent compressive strength and suitable setting time was prepared, with addition of modified starch. The CPC showed a good anti-washout property and the degradation time of the cement met with the new bone growing. This material is supposed to be used in orthopedic and maxillofacial surgery for bone defects.

[Clinic research of the effect of bFGF on human degenerated nucleus pulposus cells].

AIM: To determine the effect of bFGF on extracellular matrix and gene expression on the human de-generated nucleus pulposus cells. METHODS: The degenerated intervertebral disc cells were divided into 5 groups. A group: adding 100 pg/L bFGF, B group: adding 200 pg/LbFGF, C group: 500 pg/L bFGF, D group: 1000 pg/L bF-GF, E groups: control group, without interfering factors. The type II collagen and GAG mRNA expression were test, type II collagen content and glycosaminoglycan content of the supernatant were test. RESULTS: bFGF stimulated de-generated nucleus pulposus cells, collagen II, GAG mRNA, collagen type II and glycosaminoglycan expression of the extracellular matrix were increased significantly on the 7 days compared with the control group (P < 0. 05). type II collagen and GAG mRNA were significantly lower than the control group on 14 days, 21 days (P < 0.05). However,collagen type II and glycosaminoglycan expression of the extracellular matrix on 14 days, 21 days were still higher than normal (P <0.05). CONCLUSION: bFGF increase GAG and type II collagen mRNA expression, increased extracellular matrix type II collagen and GAG expression in short-term.