Xinwei Liu

Composite scaffolds of mesoporous bioactive glass and polyamide for bone repair

A bone-implanted porous scaffold of mesoporous bioglass/polyamide composite (m-BPC) was fabricated, and its biological properties were investigated. The results indicate that the m-BPC scaffold contained open and interconnected macropores ranging 400–500 μm, and exhibited a porosity of 76%. The attachment ratio of MG-63 cells on m-BPC was higher than polyamide scaffolds at 4 hours, and the cells with normal phenotype extended well when cultured with m-BPC and polyamide scaffolds. When the m-BPC scaffolds were implanted into bone defects of rabbit thighbone, histological evaluation confirmed that the m-BPC scaffolds exhibited excellent biocompatibility and osteoconductivity, and more effective osteogenesis than the polyamide scaffolds in vivo. The results indicate that the m-BPC scaffolds improved the efficiency of new bone regeneration and, thus, have clinical potential for bone repair.

Application of a shape-memory alloy internal fixator for treatment of acetabular fractures with a follow-up of two to nine years in China

Displaced acetabular fractures should be treated surgically. Over the past decade, surgical approaches to the acetabulum and the surgical technique for repair of common fracture patterns have advanced. Excellent outcomes after repair of these injuries can be achieved. The aim of this study was to assess the medium-term results of reconstruction of acetabular fractures by using shape-memory alloy designed by the authors. This is a retrospective review conducted at a level 1 trauma centre. From October 1999 to July 2009, 19 patients with acetabular fractures were treated with our patented Ni-Ti shape-memory alloy acetabular tridimensional memory alloy-fixation system (ATMFS). The ATMFS device was cooled with ice before implantation and then warmed to 40–50°C after implantation to produce balanced axial and compression forces that would stabilise the fracture three dimensionally. Our results are as follows; according to the D’Aubigne−Postel scoring system: Fifteen cases out of 19 (79%) achieved excellent or good clinical results. In two patients, late complications included avascular necrosis of the femoral head (ANFH) associated with posterior dislocation of the hip joint two years after the operation. We also observed two cases of grade II or III ectopic ossification, with good hip function, and one case of traumatic arthritis. In conclusion, these results demonstrate the effectiveness of the ATMFS device for the management of acetabular fracture. The device provides continuous compression of the fracture with minimal disruption to the local blood supply.

Tracheal Traction Exercise Reduces the Occurrence of Postoperative Dysphagia After Anterior Cervical Spine Surgery

Study Design. We designed a novel anterior cervical spine surgery preoperative treatment comprising mechanical trachea/esophagus traction and compared the postoperative outcome regarding dysphagia with nontreated patients. Objective. We investigated whether the newly developed preoperative tracheal/esophageal traction exercise (TTE) treatment has an effect on postoperative dysphagia after anterior cervical spine surgery. Summary of Background Data. Dysphagia is a postoperative complication that occurs after anterior cervical spine surgery, and known treatments are perioperative application of methylprednisolone, monitoring of endotracheal tube cuff pressure, and the use of low-profile plates. Methods. We compared the neck disability index, visual analogue scale scores for arm and neck pain, and Bazaz dysphagia scores, a dysphagia index, of 2 randomized groups, 1 week, 3 weeks, 6 weeks, 3 months, and 6 months after cervical spine surgery. One group received TTE treatment for 3 consecutive days before surgery, whereas the control group did not. Results. In the first week after operation, the Bazaz dysphagia scores for patients with second- to fourth-level fusions in the TTE group were significantly better than that in the control group (P = 0.000 for second- and third-level fusions and P = 0.013 for fourth-level fusion). Also at 3 weeks after surgery, the second- to fourth-level fusion patients in the TTE group had better Bazaz scores than those in the control group (P = 0.000 for second- and third-level fusions and P = 0.004 for fourth-level fusion). There was no significant difference of neck disability index and visual analogue scale scores between the 2 groups. Conclusion. Dysphagia could be reduced in patients with multiple-level fusion after anterior cervical spine surgery by preoperative TTE treatment.

Shape memory Ni-Ti alloy swan-like bone connector for treatment of humeral shaft nonunion

From August 1990 to December 2007, 156 patients with humeral shaft nonunion were treated with our patented Ni-Ti shape memory alloy swan-like memory pressure connector (SMC). The SMC device cooled with ice before implantation was warmed to 40–50°C after implantation to produce balanced axial and compression forces to stabilise the fracture three-dimensionally. This combined with autologous bone grafting achieved bone tissue regeneration in the fracture and promoted smooth recovery of joint function, with a nonunion healing rate of 98.7% after a single SMC implantation. Failure of nonunion healing occurred in only two cases but was successfully managed by a further operation. Complications were not found in any of these patients apart from four with pre-existing radial nerve injuries. These results demonstrate the effectiveness of the SMC device for the management of humeral shaft nonunion. The device provides continuous compression of the fracture with minimal trauma to the local blood supply.RésuméD’août 1990 à décembre 2007, 156 patients présentant une pseudarthrose de la diaphyse humérale ont été traités avec notre appareil breveté en alliage de titane à mémoire de forme (SMC). Cet appareillage est refroidi par la glace avant son implantation puis réchauffé à 40–50° après implantation de façon à entraîner une compression axiale et stabiliser la fracture de façon tridimensionnelle. La combinaison d’une greffe autologue améliore encore le processus de régénération osseuse dans ces fractures et permet de retrouver une meilleure fonction articulaire et un taux de guérison de la pseudarthrose de 98,7% après une simple implantation de l’appareil (SMC). Un échec et une absence de consolidation ne sont survenus que dans deux cas et ont été traités avec succès après une deuxième intervention. Nous n’avons observé aucune complication secondaire à cet appareillage exceptés 4 patients présentant des lésions préexistantes du nerf radial. Ces résultats démontrent que cet appareillage est efficace dans le traitement des pseudarthroses de la diaphyse humérale et permet d’avoir une compression continue du foyer de fracture en minimisant au maximum les troubles de la vascularisation sanguine locale.

Stress-Shielding Effect of Nitinol Swan-Like Memory Compressive Connector on Fracture Healing of Upper Limb

In this article, the stress-shielding effect of a Nitinol swan-like memory compressive connector (SMC) is evaluated. Patients with fracture healing of an upper limb after SMC internal fixation or stainless steel plate fixation were randomly selected and observed comparatively. With the informed consent of the SMC group, minimal cortical bone under the swan-body and swan-neck was harvested; and in the steel plate fixation group, minimal cortical bone under the steel plate and opposite side to the steel plate was also harvested for observation. Main outcome measurements were taken such as osteocyte morphology, Harversian canal histological observation under light microscope; radiographic observation of fracture healing, and computed tomography quantitative scanning of cortical bone. As a conclusion, SMC has a lesser stress-shielding effect to fixed bone than steel plate. Finally, the mechanism of the lesser stress-shielding effect of SMC is discussed.

Melatonin lowers edema after spinal cord injury

Melatonin has been shown to diminish edema in rats. Melatonin can be used to treat spinal cord injury. This study presumed that melatonin could relieve spinal cord edema and examined how it might act. Our experiments found that melatonin (100 mg/kg, i.p.) could reduce the water content of the spinal cord, and suppress the expression of aquaporin-4 and glial fibrillary acidic protein after spinal cord injury. This suggests that the mechanism by which melatonin alleviates the damage to the spinal cord by edema might be related to the expression of aquaporin-4 and glial fibrillary acidic protein.

Validation of the simplified chinese version of the functional rating index for patients with low back pain.

Study Design. Cross-cultural translation and psychometric testing of the Functional Rating Index (FRI). Objective. To evaluate the reliability and validity of the adapted simplified Chinese FRI (SC-FRI) for patients with low back pain (LBP). Summary of Background Data. The FRI is a reliable and valid instrument to assess the perception of function and pain for patients with LBP. However, there is no culturally adapted, reliable, and validated FRI for use in mainland China. Methods. The translation and cross-cultural adaptation were performed following international guidelines. The SC-FRI was administered to 115 patients with LBP along with the simplified Chinese version of the Oswestry Disability Index, 36-Item Short Form Health Survey, and the visual analogue scale. Psychometric testing included internal consistency, test-test reliability, concurrent criterion validity, and construct validity. Results. A high completion rate of 96% and no floor or ceiling effects were noted for the SC-FRI. The internal consistency was good (i.e., Cronbach &agr; = 0.897 for the overall SC-FRI; range, 0.851–0.890, if an item was deleted). Test-retest reliability was excellent, with an intraclass correlation coefficient of 0.948 (95% confidence interval, 0.917–0.968). Concurrent criterion validity assessment demonstrated that the SC-FRI significantly correlated with the visual analogue scale (r = 0.852, P < 0.0001) and the simplified Chinese version of the Oswestry Disability Index (r = 0.958, P < 0.0001). Construct validity was confirmed by the significant Pearson correlation between the SC-FRI and Physical Functioning (r = −0.802, P < 0.0001), Bodily Pain (r = −0.698, P < 0.0001), Social Functioning (r = −0.573, P < 0.0001), Role-Physical (r = −0.503, P < 0.0001), and General Health (r = −0.502, P < 0.0001) domains of the 36-Item Short Form Health Survey. Conclusion. The SC-FRI showed excellent reliability and validity in the evaluation of pain and the functional health status of Chinese-speaking patients with LBP. It is simple and easy to use and can be recommended in clinical and research practice in mainland China.

Treatment of bone nonunion and bone defects associated with unsuccessful humeral condylar fracture repair with autogenous iliac bone reconstruction

BACKGROUND Our preliminary study retrospectively assessed outcomes after the use of autogenous iliac bone grafts combined with internal fixation to repair refractory bone nonunions and bone defects associated with supracondylar or intracondylar humeral fractures, or both. MATERIALS AND METHODS We identified 22 patients (14 men and 8 women) with a mean age of 33.8 years (range, 17-60 years) with bone nonunion and severe bone defects associated with supracondylar or intercondylar humerus fractures, or both. The humeral condyle in each patient was anatomically reconstructed using autologous iliac bone grafts and internal fixation. Active functional exercise was initiated 3 to 4 weeks after surgery. The following variables were assessed: preoperative and postoperative elbow range of motion, Mayo Elbow Performance Score (MEPS), and postoperative complications. RESULTS Mean follow-up was 38.6 months. Mean duration until bone union was 5.6 months. Preoperatively, 16 patients had a fair or poor MEPS (<75). At final follow-up MEPS was excellent (>90) in 8, good (75-90) in 9, fair (60-74) in 4, and poor (<60) in 1 patient. Postoperative heterotopic ossification anterior to the elbow joint occurred in 2 patients. CONCLUSIONS Our preliminary results suggest that anatomic reconstruction of the humeral condyle using autogenous iliac bone grafting with internal fixation can improve elbow joint function in patients with bone nonunion and bone defects associated with supracondylar or intracondylar humeral fractures, or both. Larger scale studies are warranted to confirm our findings and compare the efficacy of this vs other surgical approaches.

Effects of Wharton's jelly cells of the human umbilical cord on acute spinal cord injury in rats, and expression of interleukin-1β and nerve growth factor in spinal cord tissues

To study the effects of Whartons jelly cells (WJCs) on acute spinal cord injury (SCI), 81 rats were divided into a sham surgery group, a model group, and a WJC transplantation group (n = 27). Motor functions of the model and WJC transplantation groups were partially recovered, and the recovery was better in the latter group. The WJC transplantation group had integral spinal cord tissues. Compared with the model group, the WJC transplantation group expressed significantly less interleukin-1β (IL-1β) and more nerve growth factor (NGF) (P < 0.05). WJC transplantation changed the microenvironment of the SCI site, inhibited IL-1β expression, increased NGF expression, promoted the recovery of neurological function, and relieved secondary SCI.