Application of locking compression plate in treatment of calcaneal fractures / 中华骨科杂志

Objective To evaluate the clinical effect of the treatment for calcaneal fractures by locking compression plate.Methods From January 2008 to December 2011,30 patients with 40 calcaneal fractures were operated with locking compression plate.There were 25 males (33 feet) and 5 females (7 feet) with an average age of 44.8 years (range,22-60 years).Fifteen feet were on the left side,and 25 feet were on the right side.All patients had closed fractures,with complicated spinal injury in 2 patients.According to Sanders classification,20 feet were type Ⅱ[fractures,15 feet were type Ⅲ,and 5 feet were type Ⅳ.The lateral approach was adopted for all the patients in the treatment in which locking compression plate fixation was used but no external fixation.Early and suitable rehabilitation was carried out postoperatively.The patients could bear part of the loading six weeks after the operation and all the loading twelve weeks after the operation.The results were validated using the Anerican Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale.Results The patients were followed up for 8-20 months (average,12 months).Bone union occurred in all cases with roentgenographic evidence during 8-12 weeks postoperation (average,10 weeks).None of the patients had such complications as nerve injury or osteomyelitis.Incision dehiscence occurred in one case in which a little part of titanium plate and screw was exposed,but the incision was healed by dressing 1 month later.Two patients had subtalar arthritis and suffered from the pain while walking.Of the two patients,the pain was relieved for one after the operation of subtalar joint fusion,and the other was lost to the follow-up after he or she refused further treatment for economic reasons.According to AOFAS foot score standard,the effects of 20 cases were excellent,17 were good,and 3 were fair.The excellent and good rate was 92.5％.Conclusion The application of locking compression plate is an effective and satisfied treatment of calcaneal fractures which is beneficial for healing and functional exercise.Moreover,the rate of soft tissue complication after operation is low.

Finite element analysis of talar ischemic necrosis / 中国组织工程研究

BACKGROUND: Precise clinical treatment of talar ischemic necrosis remains controversial at present.OBJECTIVE: To observe the changes in the stress and its distribution on talar trochlear articular surface in case of talar necrosis at different levels.METHODS: The present study adopted eight ankle specimens to establish the three-dimensional finite element model of ankle. Through changes in the talar necrosis volume of these models, this study analyzed the change law of talar trochlear articular surface stress and its distribution and calculated the critical necrosis volume of traumatic foot and ankle arthritis or talar collapse that may be induced by talar ischemic necrosis.RESULTS AND CONCLUSION: The experiment successfully established the three-dimensional finite element model of ankle. This study found that talar trochlear articular surface stress distribution showed little change in case of talar medial and lateral necrosis at a lower level; when medial talar necrosis volume reached (26.6±1.5)%, and lateral talar necrosis volume reached (35.0±2.5)%. Stress concentration phenomenon occurred in the boundary area between talar necrosis tissue and normal osseous tissue, and the stress area took the shape of irregular pattern. It is suggested that surgical treatment should be considered due to the high-risk induction of ankle-foot traumatic arthritis or talar collapse.

Effect of Methylprednisolone on Surgical Treatment of Cervical Spondylotic Myelopathy / 中国康复理论与实践

@# Objective To investigate the effects of methylprednisolone (MP) on the recovery of postoperative neurological functions due to cervical spondylotic myelopathy.Methods 114 patients with cervical spondylotic myelopathy were divided into the MP group and the control group with 57 cases in each group. The cases of the MP group were treated with MP (20 mg/kg, iv) 30 min prior to the decompression. Those of the control group underwent anterior decompression only. The complications of patients in two groups were compared. The neurological functions of all patients were graded according the ASIA score system preoperatively and at 1st day, 2nd week and 6th month postoperatively.Results Compared with the control group, the neurological functions of the cases in the MP group improved significantly after operation ( P＜0.05).Conclusion For patients with cervical spondylotic myelopathy, MP used during operation can improve postoperative neurological function recovery.

Effect of Methylprednisolone on Surgical Treatment of Cervical Spondylotic Myelopathy / 中国康复理论与实践

@# Objective To investigate the effects of methylprednisolone (MP) on the recovery of postoperative neurological functions due to cervical spondylotic myelopathy.Methods 114 patients with cervical spondylotic myelopathy were divided into the MP group and the control group with 57 cases in each group. The cases of the MP group were treated with MP (20 mg/kg, iv) 30 min prior to the decompression. Those of the control group underwent anterior decompression only. The complications of patients in two groups were compared. The neurological functions of all patients were graded according the ASIA score system preoperatively and at 1st day, 2nd week and 6th month postoperatively.Results Compared with the control group, the neurological functions of the cases in the MP group improved significantly after operation ( P＜0.05).Conclusion For patients with cervical spondylotic myelopathy, MP used during operation can improve postoperative neurological function recovery.

Histological observation of cyclosporin A effects on ossification of demineralized bone matrix / 中国组织工程研究

BACKGROUND:Demineralized bone can be used as the scaffolds of osteoblasts,and body tissue developed immunologic rejection to demineralized bone.OBJECTIVE:To investigate the histological changes of cyclosporin A(CSA) effect on ossification of demineralized bone,in addition,to explore the feasibility of demineralized bone served as ideal available bone substitute material.DESIGN,TIME AND SETTING:The randomized control experiment of animals was performed at the Experimental Center of Second Hospital of Dalian Medical University between March 2007 and April 2008.MATERIALS:Sixteen New Zealand rabbits were divided into the control and experimental group of homogenic decalcified bone,control and experimental group of heterogenous decalcified bone.CSA was produced by Beijing Novartis Pharmaceutical Co.,Ltd.METHODS:Decalcified bone prepared from rabbits was served as homogenic decalcified bone,and decalcified bone prepared from dogs were served as heterogenous decalcified bone.Sixteen rabbits were randomly divided into 4 groups:the control and experimental group of homogenic decalcified bone,control and experimental group of heterogenous decalcified bone,with 4 rabbits in each group.Each rabbit was implanted with homogenic or heterogenous decalcified bone,respectively,2 samples per side.2 mg/kg CSA or 2 mg/kg placebo was intramuscular injected in the experimental or control groups for 4 weeks.Samples were examined by hematoxylin-eosin staining and light microscope.MAIN OUTCOME MEASURES:The histological observation of decalcified bone in each group.RESULTS:Homogenic allogeneic bone induced formation in all implants.CSA did not induce morphological changes of homogenic allogeneic bone.In the heterogenous decalcified bone treated group,at 4 weeks,there was no bone formation or chondrocytes production in the control group,but there was cartilage and bone formation in the experimental group.CONCLUSION:CSA did not alter the morphology of bone induction by homogenic allogeneic bone.Immunologic reactions may inhibit bone induction by heterogenous decalcified bone,which can be counteracted by treatment with CSA.CSA can increase the rate of nonunion or bone defect using heterogenous decalcified bone.

Anterior cervical decompression and autograft fusion with plate fixation for treating spondylotic cervical myelopathy(report of 32 cases) / 中国矫形外科杂志

[Objective]To evaluate the clinical effect of anterior cervical decompression and autograft fusion with plate fixation on spondylotic cervical myelopathy.[Methods]From February 2002 to April 2008,32 cases of spondylotic cervical myelopathy were treated with anterior cervical decompression and autograft fusion with plate fixation.During the follow-up,the effect of fusion was observed for 12 months,complications were observed,and the results were evaluated by JOA.[Results]Thirty-two patients were followed up for 6～24months(15 months on average).Symptoms after operation were apparently found or cured.The JOA grade raised from 7～10 before operation(average 8.6) to 12～14(average 12.8) after treatment.The mean time for interbody fusion were 12 weeks,and its effective rate was 100 %.Cervical hematoma was found 3 hours postoperatively in 1 case,and symptom was relived after drainage treatment.Screw loosening was found after operation in another case,solid fusion of the fixation segment was achieved after external fixation for 6 months.[Conclusion]Spondylotic cervical myelopathy patients can be treated through the surgical method with anterior cervical decompression and autograft fusion with plate fixation.The method can release the anterior pressure on the spinal cord,and significantly increase the rate of interbody fusion.

A theoretical model study of open section effect on the mechanical properties of long bone / 生物医学工程学杂志

The mechanical model of femur mid-diaphysis with a rectangular open section in the exterior cortex was developed and a finite element method was adopted in calculating and analysing the changes of torsional stiffness and the stress distribution when the dimension of the open section altered. It showed that the open section with a length of 1 OD (femur mid-diaphysis diameter) had little influence on the femur torsional stiffness or stress distribution. The torsional stiffness decreased most dramatically as the length increased from 2 to 4 OD. Shear stress peaked at the center of the open section. This conclusion provides an important theoretical ground for the operative methods and the dimension control of an open section in clinical orthopaedics.

Effect of low stress environment on bone density and geome-morphology of rat femur / 生物医学工程学杂志

6-week old rats were subjected to sciatic nerve resection and the right hindlimbs were then under a low stress environment. Bone mineral density (BMD) of different regions and geome-morphological parameters of femurs were measured. The results showed that the increase in the diameter, subperiosteal area and bone mineral density of femurs were suppressed obviously under low stress environment. But the sensitivity of BMD of different regions of the femur to the low stress environment was different. The suppression of the increase in femoral BMD was composed of an early impairment in the gain of BMD at the femoral metaphysis, which is rich in trabecular bone, and a sustained reduction in the gain of BMD at the femoral diaphysis, which is rich in cortical bone. The results of geome-morphology suggested that the early reduction in the increase of BMD at the metaphysis was due to an enhancement of bone resorption, whereas the suppression of gain in cortical bone mass and size is the result of a sustained reduction of periosteal bone formation.

Experimental study of bone and cartilage transplantation to repair the defect of articular cartilage / 中国康复理论与实践

@#ObjectiveTo explore the effect and feasibility of autograft and allograft bone and cartilage transplantation.Methods63 rabbits were made experimental defect in the same side knee joint,and were divided randomly into group A(autograft group),group B(allograft group) and group C(control group).Group A was divided further into 2 column limiting motion subgroup(A2M group),not limiting motion subgroup(A2N group) and 4 column subgroup(A4M group).In the same way,group B was divided further into B2M group,B2N group and B4M group.Every subgroup included nine rabbits,and the transplantation was made in no weight-bear area of knee joint.The generally observation were made,the joint movable range and the thickness of the repairing tissue were measured,histology change of transplanted tissue(through light,electronic microscope)were observed.ResultsGroup A had a satisfactory result,and the result of no limiting groups were better.The result of A4M group was better than A2M group (P≤0.05).The result of group B was not good.ConclusionThe bone-cartilage column of small diameter and general number are beneficial in repairing the defect of joint cartilage.The allograft bone and cartilage transplantation can cause seriously immunoreaction and the absorption of cartilage pole,and is detrimental to repair the defect of joint cartilage.

Biomechanical test study of rat femurs growing under different stress environment / 生物医学工程学杂志

By creating two kinds of stress environment in the same animal model, we performed a three-point bending test and a compressing test on the rat femurs growing under different stress conditions to characterize the effect of stress on bone mechanical properties. The right hindlimbs were subjected to sciatic nerve resection to become cripple and were used as unloading group; the left hindlimbs bore excess load and made up the overloading group; the normal rats were used as control group. The animals were encouraged to exercise for half an hour everyday in the morning, noon and evening. The experiment observation finished in four weeks. The biomechanical parameters of femur diaphyses were measured. The experiment results showed that stress environment may change several mechanical parameters of rat femurs. This study indicated that bone tissues can adapt to its stress environment by changing its mechanical properties. The experimental model in this article is practical and reliable.