Objective To study the clinical outcome of percutaneous vertebroplasty (PVP) for the s disease who had been suffering severe back pain even after conservative therapy for months were treated with PVP. Their preoperative CT images indicated nonunion of factures and "vacuum signs". Dynamic X-ray films demonstrated formation of pseudoarthrosis in the involved vertebral bodies in some eases. Their back pain was evaluated with visual analogue scale (VAS). Their preoperative and postoperative VAS scores and radiological indexes were compared. Results The mean VAS scores were 7.0±1.2 preoperatively, but 3.1±1.5 at the follow-up (P < 0.05) . The height of anterior margin of involved vertebral body was (2.1±0.3) cm pre-operatively, but (2.3±0.2) cm at the follow-up (P < 0.05). The ratio of anterior margin height to posterior margin height of the involved vertebral body was 0. 67±0. 10, but 0.84±0.08 at the follow-up (P<0.05), The focal kyphosis angle was 27.3°± 6.4° preoperatively but 20.7°±5.0° at the follow-up (P < 0.05). No pulmonary embolisms or neurological injuries happened. Conclusion PVP is an effective method for anterior margin of the involved vertebral body partially, and decrease the focal kyphosis.

Objective To investigate the advantages of the external fixators used in the treatment of pelvic fracture. Methods From April 2002 to July 2008, 55 patients with unstable pelvic fracture were treated respectively with simple external fixators, external fixators plus traction and external fixators plus in-ternul fixation according to their different Tile classifications. Results Of this group, 51 cases were followed up for an average of 11 months, 2 cases died because of multi-injuries, and 2 cases were lost in the follow-up. All of the 51 patients obtained bony union. On average, it took 11 (6 to 14) weeks to achieve weight-bearing walking, and 12 (8 to 14) weeks to remove the external fixators for the patients. By Liu Li-ming's evaluation system, the good to excellent rate was up to 88.2%. Conclusions The pelvic fractures of Tile B1 and B2 can be treated with simple external fixators and those of Tile C with external fix-ators plus internal fixation or traction to achieve fracture reduction and stability of the pelvic ring. For the patients with multi-injuries, external fixators used in the emergency treatment can stabilize the pelvic ring, reduce blood loss and improve the success rate.

Objective To compare the clinical results of minimally invasive percutancous plate os-teosynthesis (MIPPO) and open reduction with internal fixation (ORIF) for treatment of distal tibial fractures. Methods From October 2006 to June 2007, 94 cases of closed distal tibial fracture with intact articular surface were treated by internal fixation with plates. Of them, 42 were treated with ORIF and 52 with MIPPO. We retrospectively analyzed their union time, malunion and complications. Results The average follow-up was 14.5 (8 to 24) months. In the ORIF group, 35 cases got union, 3 cases delayed union and 4 cases nonunion. The average time for union was 3.83 (3 to 8) months. There were no cases of malunion and 2 cases of superficial infection in this group. In the MIPPO group, 47 cases obtained union, 5 cases delayed union and none nonunion. The average time for union was 3.66(2 to 8) months. No significant differences were found between the 2 groups in total union time or in the union time for Type AI, Type A2 and Type B fractures respectively. The union time for Type A3 fracture was longer in the MIPPO group than in the ORIF group, but the union time for Type C fracture in the MIPPO group was shorter than in the ORIF group. In the MIPPO group, external rotation occurred in 2 cases and posterior angnlation displacement in 3, and 8 cases com-plained of discomfort around the ankle which was relieved after removal of the plate. Conclusions Gen-erally speaking, there is no significant difference between ORIF and MIPPO in union time for distal tibial fractures. ORIF may be superior to MIPPO in treatment of Type A3 fracture, but inferior to MIPPO in treatment of Type C fracture. A high rate of delayed union may be expected in patients who have been treated with MIPPO and have had anteroposterior angnlation.

Objective To explore the anti-sliding plating for Hoffa fractures by comparing the me-chanical properties of anti-sliding plates and cancellous bone screws. Methods Twenty cases of the same type of Hoffa fracture in the model femur were randomly divided into 4 even groups. Group A used 2 antegrade cancellous bone screws; Group B used 2 retrograde cancellous bone screws forwards; Group C used anti-sliding plate and locking screw fixation; Group D used anti-sliding plate and cancellous bone screw fixation. All the samples were subjected to the cycle fatigue and the maximum failure load tests. Results The fatigue test revealed no significant difference in the mean maximum displacements at the 10, 100, 1000, 10 000 cycles between the 4 groups. In the maximum failure load test, there were significant differences between Group A [(1224±72) N] and Groups C and D [(2183±227) N and (2124±235) N], as well as between Groups B [(1405±235) N] and Groups C and D; there was no significant difference between Group A and Group B, neither between Group C and Group D, Conclusions In the initial period after secure fixation for Hoffa fractures, anti-sliding plates and cancellous bone screws can all provide satisfactory mechanical stability and strength. But anti-sliding plating is recommended for cases of long healing expected, patients with great body mass index, and patients with poor compliance.

Objective To explore whether the respective implantation of vascular bundles and sensory nerve tracts into a tissue-engineered bone will affect the expression of CGRP (Calcitonin gene related peptide) and its receptor. Methods Fifty-four New Zealand rabbits were randomly divided into 3 even groups for implantation of sensory nerve tracts (group A),implantation of vascular bundles (group B),and a control group of simple tissue-engineered bone (group C) . Animals were sacrificed 4,8,12 weeks after implantation,respectively. Masson staining was conducted to observe the process of bone formation and re-molding. CGRP and CGRPR-1 expressions in the new bone were measured by immunohistochemistry and Real-time PCR at 4,8 and 12 weeks after implantation. Results At all time points,the CGRP and CGRPR-1 expressions in groups A and B were significantly higher than in group C (P<0.05),and those in group A were higher than in group B too (P<0.05) . Over time,the expressions of CGRP and CGRPR-1 mRNA in each group in the new bone tissue were gradually reduced after an initial increase. The neuropeptide expression at the 8th week was higher than those at the 4th and 12th weeks. The neuropeptide expression at the 4th week was the lowest. The expression of CGRP was mainly localized in the periphery of newly generated bone,periosteum and the blood vessels. The expression of CGRPR-1 was mainly localized in the periphery of osteoblasts. Conclusions Implantation of either vascular bundles or sensory nerve tracts can promote neuropeptide secretion. The vascular bundle implantation may result in higher expressions of CGRP and CGRPR-1 than sensory nerve tract implantation.

Objective To evaluate the treatment of supra-condylar fractures of the humerus (12-B1.2 by AO classification) with a unilateral external fixator. Methods From 2003 to 2006,28 cases of supra-condylar fractures of the humerus were treated with a unilateral external fixator. They were 15 males and 13 females. Their average age was 43 (24 to 58) years old. They were all closed fractures and 2 cases complicated with radial nerve injury. Results All were followed up for an average of 28 (12 to 54) months. All fractures united with an average healing time of 4.5 months. The 2 cases of radial nerve injury recovered completely. Five cases had infection of pin holes. The patients had an average elbow score (Money and Bryan system) of 97 and an average shoulder score (Constant and Murley system) of 98. Conclusion The unilateral external fixator is appropriate for supra-condylar fractures of the humerus ( 12-B1.2 by AO classification),because it provides not only effective fixation but also early functional rehabilitation.

Objective To compare olfactory ensheathing cells (OECs) and Schwann cells (SCs) in respect of their abilities to repair nerve defects. Methods OECs and SCs were cultured in vitro for 2 weeks before they were purified and condensed for later transplantation. Sixty adult female Wistar rats were randomized into 3 even groups. After a 25 mm length of axons was excised but the epineurial lumen was re-tained, the left sciatic nerves were anastomosed to the proximal ends. Cell culture medium, SCs and OECs were transplanted into the epineurial lumen in A, B, C groups respectively. Three months postoperatively, regeneration of the injured sciatic nerves was evaluated by gross observation, microscopy, transmission elec-tron microscopy, transportation distance of retro-marked fluorescence red, immunofluorescence assay of the glial fiber acid protein and nerve growth factors, enzyme linked immunoassay of myelin basic protein and neurofilament protein, as well as ankle function evaluation. Results By gross observation, regeneration of the injured sciatic nerves was the best in group C and the poorest in group A. In aspects of growth of nerve fibers observed by microscopy and transmission electron microscopy, the transportation distance of retro-marked fluorescence red in the injured sciatic nerves observed by fluoroscopy, glial fiber acid protein and nerve growth factors tested by immunofluorescence assay, concentrations of myelin basic protein and neuro-filament protein in the injured nerves tested by enzyme linked immunoassay, as well as in the mean ankle function score, group C was the best, next was group B , and group A was the poorest. The differences be-tween groups had statistical significance (P < 0.05). Conclusion OECa transplantation can repair in-jured nerves and has better effects than SCs transplantation.

Objective To discuss the clinical treatment of unstable dislocation of the sternoclavicular joint with clavicle hook plates. Methods From April 2005 to October 2007, 19 cases of unstable dislo-cation of stemoclavicular joint were treated with open reduction and internal fixation by clavicle hook plates. There were 17 cases of Grade type Ⅲ and 2 cases of Grade type Ⅱ. After open reduction and internal fixation, all patients received arthroplasty and repair of eostoclavicular and sternoclavicular ligaments. Results None had intraoperative injury to nerves and blood vessels. Follow-ups from 6 to 24 (mean, 8) months showed 16 excellent cases, 2 good cases and 1 fair case by Roekwood criteria, the good to excellent rate being 94.7%. The healing duration lasted 3 to 6 (averaging 4) weeks. No infection, sliding or loosening of internal fixation, nonunion or re-dislocation was found postoperatively. Conclusion The clavicle hook plate is an effective and advanced surgical treatment of sternoclavieular joint injuries, because its easy and mini-invasive operation can provide sturdy fixation and lead to good functional recovery.

Objective To discuss the effects, indications and methods of π-shaped locking com-pression plates plus open reduction for Barton fractures. Methods From January 2006 to January 2007, 21 cases of Barton fractures were treated by open reduction from dorsal incision and fixation by π-shaped locking compression plates. Of them, 14 also had bone grafting and 6 had protection by a plaster brace. Results Follow-ups for 6 to 18 (average, 10) months showed all the patients got bone union. The differences between preoperative and postoperative measurements in palmar inclination, ulnar deviation and relative length of distal radius were statistically significant (P < 0.05). At the last follow-up, the affected wrist showed no significant difference from the opposite side in dorsal extension, palmar flexion and ulnar deviation (P > 0.05) except in ulnar deviation (P < 0.05). According to the improved Gartland and Werkey grading system, the wrist function was evaluated as excellent in 15 eases, good in 4, and fair in 2. The good to excellent rate was 90. 5%. Conclusion Open reduction from dorsal incision and fixation by π-shaped locking compression plate is an effective treatment for Barton fractures.

Objective To explore the best ratio of platelet-rich plasma (PRP) to activator and the synergistic action of thrombin and the growth factors in PRP gel on proliferation of human marrow-derived mesenchymal stem cells (hBMSCs). Methods The activator was made up of 1000 U bovine thrombin and 1 mL 10% calcium chloride solution. PRP was mixed with the activator at the ratios of 1:1, 5:1, 10:1, 20:1, 40:1 respectively in groups A, B, C, D and E. A quantitative sandwich enzyme-linked immunosorbent assay (ELISA) was used for examining the amounts of transforming growth factor-β1 (TGF-β1) and platelet derived growth factnr-AB (PDGF-AB) in PRP gel in each group after incubation for 0,1,8,24, and 120 hours. MTT assay was used to evaluate the effect of PRP gel in each group on hBMSCs proliferation. Results When PRP was mixed with thrombin, concentrations of PDGF-AB and TGF-β1 in PRP gel increased immediately and reached the peak value in 1 hour. The PRP gel in groups B, C, and D contained the highest amounts of PDGF-AB and TGF-β1, and accelerated hBMSCs growth re-markably. The cells proliferation in group A was inhibited. Conclusions The effect of PRP on the hBMSCs proliferation depends on the concentrations of PDGF-AB and TGF-β1 in PRP. Thrombin may influ-ence the hBMSCs proliferation by regulating concentrations of growth factors in PRP to certain extent, but too high a level of thrombin may inhibit hBMSCs growth.