Biomedical subjects

Leiting Chi

Publications and source records attributed to Leiting Chi.

5 recordsLinked to original sources

PubMed2006

[Exploration of surgical approaches of complex tibial plateau fractures].

OBJECTIVE: To evaluate the surgical treatment and its results of complex tibial plateau fractures. METHODS: From May 2003 to November 2004, 24 cases of complex tibial plateau fractures were treated by two-incision approaches. There were 16 males (including 1 case of bilateral), and 8 females, with mean age of 40.6 years (21-65 years), eleven fractures occurred in left extremity and 14 in the right. No patients suffered open fractures. Fracture was caused by fall from height in 10 cases, by traffic accident in 12 cases and by another causes in 2 cases. According to Schatzker classification, type V fracture was found in 14 extremities, type VI in 11 extremities. All cases were operated with two-incision approaches and double-plates fixation. The operation was performed 6-15 days after injury with mean 10.4 days. RESULTS: All cases were followed up from 12 to 23 months (mean 15.6 months). Time of the bone healing was 6-9 months, with mean 7.4 months. No reduction of anatomy was achieved because of comminuted fractures of articular surfaces in 2 limbs. The line of the lower extremity did not recover because of metaphysis comminution in 1 limb, which led to knee varus. Epidermal necrolysis was observed in 3 limbs, and the wound healed after change dressing. The function of the knee was evaluated according to Rasmussen's criteria, the results were excellent in 10 limbs, good in 8 limbs, fair in 3 limbs, and poor in 4 limbs. CONCLUSION: The two-incision approaches reduced the complication of soft-tissue injury, which is conductive to reduction of articular surface. Double-plates provide a sufficient internal fixation. It can permit early motion of knee joint. Therefore, two-incision approach are an effective surgical approach of treatment of complex tibial plateau fractures.

Adult↗

PubMed2006

[The biomechanical study of rotating-arm self-locking intramedullary nails in comminuted femoral shaft fractures].

This study was sought to compare and evaluate the biomechanical properities of rotating-arm self-locking intramedullary nails (RSIN) with domestic femoral intramedullary nail (DFIN) in communited femoral shaft fractures. A 2 cm midshaft defect was created on seven pairs of cadaver femur, and fixed with two kinds of intramedullary nails. Then the torsion, four-point bending and axial loading to failure were tested on these models. The load versus deformation curve was generated from the load recorded by the load cell and the deformation simultaneously recorded by the linear variable displacement transducer. The mean torsional stiffness of the femora fixed with RSIN was 0.98 Nm/degree, which was significantly less than that fixed with the similar nails reported in documents, and the mean value of bending stiffness of the femur fixed with DFIN was larger than that of the femur fixed with RBIN, but there was no significant statistic difference. For use in fracture models under compression load beyond 1200 N, the RBIN was more rigid than DFIN, which provided the biggest load. All the parameters of the test with nails were greater than that for femur fixed with nails. In conclusion, FBIN probably provides enough strength and rigidity for use in communited femoral shaft fractures.

Adult↗

PubMed2005

[A preliminary clinical study on absorbable screws].

To evaluate the application of self-reinforced ploy-DL-lactide (SR-PDLLA) absorbable screws in the treatment of spongy bone and intra-articular fractures, the internal fixation with SR-PDLLA absorbable screw was performed on 58 cases,of which 25 were medial malleolus fractures, 14 condyle of humerus fractures, 9 tibial plateau fractures, 7 ulnar olecranon fractures, and 3 lateral malleolus fractures. Observations were made on the orthopaedic operation sites and overall conditions frequently and radiography was performed for periodic analysis. The results showed that SR-PDLLA absorbable screws were particularly effective and reliable, they had good biocompatibility in the treatment of spongy bone and intra-articular fractures and could be used safely in clinical practice.

Absorbable Implants↗

PubMed2004

[Biomechanical study on rotating-arm self-locking intramedullary nail in the treatment of tibial shaft fracture].

We have designed a new kind of self-locking intramedullary nail for the treatment of unstable fracture of the middle and distal tibial shaft and have compared it with the interlocking nail by means of biomechanical experiments. The data could be used as a basis for clinical application. Fourteen formalin-fixed tibials of adults were made into unstable fracture models with a 2cm bone defect each. They were divided into 2 groups. Group 1 was fixed with self-locking intramedullary nail and group 2 was fixed by interlocking nail. All specimens were submitted to biomechanical test. The data were analysed by t test. The results showed there is no difference in anti-bending stiffness between the self-locking intramedullary nail and the interlocking nail. The anti-rotating and anti-compressing stiffness of interlocking nail is slightly better than that of self-locking intramedullary nail, but still the firmmess of the self-locking intramedullary nail in resisting rotation can meet the requirement of biological fixation. Its structure is reasonable, simple, practical, and it can resist certain harmful stress.

Biomechanical Phenomena↗

PubMed2003

A single nucleotide deletion of 293delT in SEDL gene causing spondyloepiphyseal dysplasia tarda in a four-generation Chinese family.

Spondyloepiphyseal Dysplasia Tarda (SEDT; MIM 313400) is a rare genetically heterogeneous disorder of vertebral and epiphyseal growth resulting in disproportionally short-trunked short stature, barrel-shaped chest, and dysplasia of the large joints. It is caused by the mutations of SEDL gene. The distinctive radiological signs and the X-linked mode of inheritance make it easy to diagnose. Here a four-generation Chinese SEDT family has been analyzed and the disease-causing mutation has been found. After polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis and DNA sequencing, a previously unreported deletion of T in exon 5 of SEDL gene (i.e. 293delT) was observed and seven individuals in the family carried the mutation. It results in frameshift and a putative truncated protein with the 97 N-terminal amino acids, and 9 changed amino acids. Therefore, loss of function of the gene could be predicted. However, this mutation has not been detected in 50 age and sex matched unrelated controls.

Adult↗