Research Progress on Hierarchical Structure of Cortical Bone and Its Toughening Mechanisms / 医用生物力学

Cortical bone is a kind of natural biological composite materials, which is mainly composed of tropocollagen molecules and nanoscale hydroxyapatite mineral crystals. It possesses high strength, stiffness and fracture toughness and has the ability to tolerate damage and self-heal. In the long process of evolution, bone tissues form the biomechanical strength and toughness to meet its functional needs. The excellent mechanical properties of cortical bone are closely related to its hierarchical microstructure. This paper reviewed the hierarchical microstructure of cortical bone and its toughening mechanisms, which would contribute to understanding the diagnosis, prevention and treatment of aging-related osteoporosis and the pathological mechanism of bone diseases.

Establishement for regional pelvic trauma database in Hunan Province / 中南大学学报(医学版)

Objective:To establish a database for pelvic trauma in Hunan Province,and to start the work of multicenter pelvic trauma registry.Methods:To establish the database,literatures relevant to pelvic trauma were screened,the experiences from the established trauma database in China and abroad were learned,and the actual situations for pelvic trauma rescue in Hunan Province were considered.The database for pelvic trauma was established based on the PostgreSQL and the advanced programming language Java 1.6.Results:The complex procedure for pelvic trauma rescue was described structurally.The contents for the database included general patient information,injurious condition,prehospital rescue,conditions in admission,treatment in hospital,status on discharge,diagnosis,classification,complication,trauma scoring and therapeutic effect.The database can be accessed through the internet by browser/servicer.The functions for the database include patient information management,data export,history query,progress report,video-image management and personal information management.Conclusion:The database with whole life cycle pelvic trauma is successfully established for the first time in China.It is scientific,functional,practical,and user-friendly.

Research progress of bone microarchitecture and microdamage detection / 中国组织工程研究

BACKGROUND:Bone fragility and poor bone quality due to osteoporosis are a major and increasing concern. Bone microarchitecture and microdamage, the important factors of bone quality, their detection technology and instrument have experienced a long development process. OBJECTIVE:To give a brief introduction of the concept of the bone microarchitecture and microdamage, then to summarize the research progress of their detective methods. METHODS:PubMed and CNKI databases were retrieved for reviews and articles related to bone microarchitecture and microdamage published from January 1990 to June 2016 using the keywords of“bone microarchitecture, bone microdamage and detect/detective/detecting”in Chinese and English, respectively. Finaly a total of 65 articles were selected for overview. RESULTS AND CONCLUISON:(1) Bulk staining is a quick and useful way to confirm and assess linear microcracks and diffuse damage. Micro-CT and confocal microscopy al ow visualization at the micron scale, and are useful tools to understand the three-dimentional nature of bone microdamage. Scanning electron microscope lacks the ability to investigate large regions of microdamage, but al ows users to probe in extensive details at the nano scale. (2) Ultimately, we recommend the use of multiple imaging modalities according to the experimental needs to obtain useful information about bone quality and microdamage formation, across the scales of hierarchy in bone.

Clinical application of the polyfoliate perforator flap with decending branch of the lateral circumflex femoral artery: 16 cases report / 中华显微外科杂志

Objective To describe a technique to achieve primary donor-site closure, extend applications and minimize donor-site morbidity by applying the double skin paddle principle.Methods All 16 cases of the double skin paddle anterolateral thigh perforator flap reconstruction from May, 2008 to June, 2014 were reviewed.Defects locations included calf, dorsum pedis or planta pedis.A long anterolateral thigh perforator flap was marked out using standard points of reference.At least two separate cutaneous perforator vessles were identified on hand-held Doppler.Separating and dissecting flap at superficial layer of fascia lata was adopted in all cases.Then skin paddle was then divided between the two cutaneous perforators to give two separate paddles with a common vascular supply which was the descending branch of the lateral circumflex femoral artery.The skin paddles could be used to cover complex skin defects, whilst still allowing for primary donor-site closure.Results Fifteen patients were successfully treated with the double skin paddle anterolateral thigh perforator flap with no major complications.One case was suffered with partial skin flap necrosis.The type A dumbbell-like flaps was used to cover defects involving two different units of the foot.The type B pattern were stacked side by side on a flap inset, effectively doubling the width of the flap, to resurface a large defect of a single unit of the calf.The type C pattern was used to repair adjacent skin defects.In all cases, the donor site was closed directly.All patients were satisfied with their outcomes.Conclusion The double skin paddle anterolateral thigh perforator flap is an excellent method of resurfacing large defects of the extremity involving multiple subunits with improved morbidity and cosmesis of the donor site.

Vascularized chimerical perforator flaps of deep circumflex iliac artery repairing bone and soft tissue defects of limbs / 中华显微外科杂志

Objective To explore the clinical effect and experience of separating deep circumflex iliac artery osteocutaneous perforator flap (DCIAP) from the bone flap.Methods According to local applied anatomy of groin,vascularized chimerical flaps of deep iliac circumflex artery was designed and applied.From May,2008 to June,2012,12 patients who combined bone and composite skin and soft-tissue defects were positioned by color dopplar ultrasound before operation and treated with vascularized chimerical flaps of deep iliac circumflex artery.The deep circumflex iliac perforator flaps was 8 to 19 cm in length and 2 to 6 cm in width,and the iliac bone grafts ranged from 5 to 8 cm in length.Results All flaps were fully survival.After 8-10 months postoperative followed-up,all the bone defect gained healing.The function and appearance of cutaneous flaps were satisfactory.There was no serious complication in donor sites of groin.The average time of healing was 9 (8-10) months.Conclusion Vascularized iliac bone graft and a perforator flap are nourished by the same deep circumflex iliac artery.There is more mobile scope and only 1 blood vessel between the bone graft and skin flap,which should be called chimeric perforator flap based on the deep iliac circumflex artery,and is a kind of good method to repair bone and soft-tissue defects of limbs.

Epidemiological investigation of pelvic fracture in 9 third-tier hospitals in 5 cities in Hunan / 中南大学学报(医学版)

OBJECTIVE@#To analyze the epidemiological characteristics and treatment situation of pelvic fractures in 5 cities in Hunan, improve the treatment and provide epidemiological data for policymakers.@*METHODS@#The clinical data of 65 patients with pelvic fractures were collected from 9 third-tier hospitals in Hunan from October 2012 to March 2013. The gender, age, cause, volume of blood transfusion, and prognosis were analyzed with SPSS 13.0.@*RESULTS@#There were 44 male and 21 female patients (2.10:1.00). The age ranged from11 to 86 years and 74.6% of the patients were between 20 and 59. The main cause was traffic injury (30 cases, 46.2%) and fall injury (22 cases, 33.8%). About 73.8% patients suffered associated injuries all over the body. By Tile's classification of pelvic fractures, the average blood transfusion of type A was 483.33 mL, that of type B was 1 026.92 mL and type C was 1 905.56 mL. Compared with type A, the treatment outcome of type C patients was worse.@*CONCLUSION@#Pelvic fractures are mostly caused in young and middle-aged males by high-energy. Tile C pelvic fractures need more blood transfusion and have poor prognosis. Patients had better be taken straight to municipal hospitals by expertise. Safety education for high-risk groups should be enhanced to reduce the incidence of pelvic fractures.

Innervation of free anterolateral thigh flap for repairing widespreadly traumatic soft tissue defects in heel / 中华显微外科杂志

Objective To explore new methods of innervating the anterolateral thigh flap(ALTF) for repairing widespreadly traumatic soft tissue defects in heel and report their initial results of clinical application. Methods Twenty-five consecutive ALTFs were transplanted in 25 patients for repairing widespreadly traumatic soft tissue defects in heel from October 2005 to October 2010. Three ways were used in this series for sensory reconstruction of ALTFs,which based on the primary researches of the anatomic and histomorphological characteristics of lateral femoral cutaneous nerve (LFCN),medial calcaneal nerve (MCN) and lateral calcaneal nerve (LCN). The first way which was of suture between reshaped LFCN and MCN or LCN was used in 16 cases, the second way which was of perineurial suture combined with epineurial suture was used in 6 cases,and the small-gap-suture way was used in the remaining cases.The section of LFCN 5-7 cm below the anterior superior iliae spine and the initial segment of MCN or LCN were selected as anastomotic position. Postoperative follow-up parameters include pain sensation, touch sensation, thermal sensibility and static two-point discrimination. Results All flaps survived,and the wounds were primary intention.Twentyfive cases followed up 9-36 months (18 months on average).All flaps restored protective sensation,and the rate of good sensory recovery was 60％. All patients restored weighing and walking, and no ulceration happened. Conclusion Satisfactory sensory function restoration can be obtained by paying attention to the distribution and variety of LFCNs, selecting suitable cutaneous nerves and rational coaptated position as well as suitable suturation means which based on the anatomic and histomorphologieal characteristics of LFCN,MCN and LCN when repairing widespread soft tissue defects in heel.

Anatomic characteristics and clinic significance of the lateral femoral cutaneous nerve / 中南大学学报(医学版)

OBJECTIVE@#To explore the reasons of poor sensation recovery after anterolateral thigh flap (ALTF) transplantation and to improve the design and sensation reconstruction of ALTF.@*METHODS@#Lower limbs from 21 adult cadavers were chosen, and the lateral femoral cutaneous nerves (LFCN) were dissected. Their courses, shape, distribution and anatomic variation were observed, the distance from original sites of LFCN's posterior and anterior branches to the anterior superior iliac spine (ASIS) were measured, and the external diameter of their main trunks,after piercing out from the inferior margin of inguinal ligament or sending out their posterior branches and their anterior branches, were measured.@*RESULTS@#The plane which the posterior branches sent out from the LFCN located at 4.8 (0~16.9) cm below the ASIS. The plane which the anterior branches sent out from the LFCN located at 14.2 (6.7~24.1) cm below the ASIS. There were 6 branches of the LFCN, namely ordinary three branches (9/21), high-level posterior branch (5/21), posterior branch absent (3/21), anterior branch absent (1/21), tiny branch, (2/21) and LFCN absent (1/21). The section of the LFCN was oblate, the external diameter of the LFCN,s main trunk after piercing out from the inferior margin of inguinal ligament or sending out its posterior branch and its anterior branch was 2.68 (1.18-4.52) mm, 2.18 (0.80-4.10) mm and 1.63 (0.44-2.60) mm, respectively.@*CONCLUSION@#Poor sensation recovery after ALTF transplantation is due to anatomic variation of the posterior branch of the LFCN. The sensory recovery of ALTF may be improved if the 2/3 low to median part of the anterolateral thigh and the main trunk of the LFCN or its plane before sending out the anterior branch is chosen for anastomosis.

Effect of PCL integrity on biomechanical features of the medial femoral condyle / 中华骨科杂志

Objective To explore the biomechanical function of PCL and its different bundles and examine the biomechanical impact of posterior cruciate ligament (PCL) integrity on the medial femoral condyle. Methods Twelve fresh human cadaveric knee specimens were subjected to different axial load (0-800 N) at 0°, 30°,60°, and 90°of knee flexion. Four surgical treatments were carried out for biomechanical testing: PCL intact, anterolateral bundle (ALB) rupture, posteromedial bundle (PMB) rupture and PCL rupure. During the test, strains of middle part of the medial femoral condyle were calculated. Results At O°knee flexion, increasing strain of the medial femoral condyle was detected in PMB rupture and PCL rupture under all loading conditions. No significant difference of strain of the medial femoral condyle was noted between PCL intact and ALB rupture under any loading conditions. Compared to PMB rupture, PCL rupture had not higher strain of the medial femoral condyle under all loading conditions. At 30°, 60° and 90° knee flexion, increasing strain of the medial femoral condyle was noted in ALB rupture under higher loading conditions and PCL rupture under all loading conditions. ALB rupture under lower loading conditions and PMB rupture under all loading conditions did not significantly increased strain of the medial femoral condyle. PCL rupture had higher strain of the medial femoral condyle than ALB rupture under most of loading conditions.Conclusion The data suggest that PMB is the major stabilizing bundle of PCL in full extension, ALB is the major stabilizing bundle of PCL in knee flexion, and both bundles function through the ROM in a codominant fashion. Partial and complete ruptures of PCL may have hazardous biomechanical impacts on the medial femoral condyle during normal movement.

Expression of interleukin 1 beta in the lateral meniscus of rabbits with anterior cruciate ligament rupture / 中国组织工程研究

BACKGROUND: Previous studies demonstrate that interleukin 1β(IL-1β) plays a great role in the degeneration of articular cartilage in knee joints which was caused by the anterior cruciate lagement (ACL) rupture; however, the role of IL-1β in the degeneration of lateral meniscus remains poorly understood. OBJECTIVE: To investigate the changes and significance of the expression of IL-1βin the lateral meniscus of rabbits with ACL rupture. METHODS: A total of 48 male, New Zealand, white rabbits, were matched mode pairs and prepared for ACL rupture models. In the experimental side, the ateral meniscus of rabbits was cut down to prepare ACL rupture models, simultaneously, the control sides were exposed without cut down. A total of 12 rabbits were secdficed under anesthesia at weeks 1, 3, 6 and 8 after model preparation. Degeneration scores of lateral meniscus and expression of IL-1β in lateral meniscus were performed. RESULTS AND CONCLUSION: With time prolonged, the scores of lateral meniscus degeneration were increased, which was higher in the experimental group than those in the control group at each time points (P < 0.05). The positive rate of IL-1β was greater in experimental group than that in the control group (P < 0.05). In addition, the positive rate of IL-1β in the experimental group was greater at weeks 3 and 6 than weeks 1 and 8 (P < 0.05), which was higher in week 8 than week 1 (P < 0.05). The results demonstrated that the highly expressed IL-1β in the experimental sides hints that IL-1β maybe a promotional factor which causes the degeneration of lateral meniscus. The decreasing of the expression of IL-1β is not a stopping signs of lateral meniscus degeneration.

Three-dimensional finite element analysis of the zygapophyseal joints following artificial lumbar disc replacement / 中国组织工程研究

BACKGROUND: With deepening of spinal biomechanics, artificial lumbar disc replacement is considered to be the optimal choice for treating degenerative lumbar disease. However, studies concerning biomechanics of artificial lumbar disc are insufficient. OBJECTIVE: To establish the three-dimensional (3-D) finite element model of artificial lumbar disc replacement and to explore the effects of artificial lumbar disc replacement on zygapophyseal joints using biomechanical analysis. METHODS: Based on normal 3-D finite element model of lumbar motion segment, L4-5 intervertebral disc, superior and inferior endplates were removed, and then, the model of SB-Charite Ⅲ disc prosthesis was added, which remained annular fibrosus and ligaments at L4-5 intervertebral space. Thus, 3-D finite element model of L4-5 segments artificial lumbar disc replacement was constructed. Biomechanical analysis of this model was processed under axial load, forward flexion, lateral bending or posterior extension moments. The stress data were contrasted with the normal 3-D finite element model of artificial disc replacement. RESULTS AND CONCLUSION: After artificial lumbar disc replacement, the data of biomechanical analysis indicated: ①There was no significant differences between the zygapophyseal joint and normal segment of stress under axial load (P > 0.01).②Compared with normal segment, the stress of anterior, posterior of upper and lower vertebral body and bilateral zygapophyseal joint had no obviously difference under forward flexion and posterior extension moments (P > 0.01). ③The stress differences between the both sides of upper and lower vertebral body and bilateral zygapophyseal joint were not significant under lateral bending moment (P > 0.01). Artificial lumbar disc replacement can keep the stress of motion segment at normal level, which can meet the needs of spinal functional reestablishment.

Transplantation of perforator flaps: Systematic review of 108 case series / 中华显微外科杂志

Objective To explore the clinical outcome of perforator flaps for reconstruction of limb soft tissue defects. Methods In this case series, from 2007 July to 2009 May, 108 cases of perforator flap to reconstruct the defects of the extremities were performed, of these, 98 were free perforator flaps, 10 were pedicled flaps. The perforator flaps included deep inferior epigastric artery perforator flap, anterolateral thigh perforator flap, thoracodorsal artery perforator flap, lateral thigh perforator flap, posterior interosseous artery perforator flap, collateral radial artery perforator flap, medial sural artery perforator flap, posterior tibial artery perforator flap, deep circumflex iliac artery perforator flap and peroneal artery perforator flap. The maximum size of the perforator flap was 44 cmx 9 cm, the minimum size of the perforator flap was 4 em x 2 cm.The donor defect was closed directly. Results Venous congestion occurred in 5 flaps, in 1 case venous congestion was overcomed after released the dressing, 4 flaps requiring reexploration for venous insufficiency,2 had a successful outcome, the other 2 flaps failed . The other 103 flaps were successful. The wounds healed without any infection complications. The follow-up ranges from 6-24 months( 10 months on average). The flaps were of good appearance and not bulky; there were only linear scars on the donor sites, the cosmesis and function of the donor sites were satisfying. Conclusion The muscle, deep fascia and motor nerve are not contained in the flap, the advantages of this type of flap is reducing morbidity of the donor site and its reliable blood supply and suitable thickness for resurfacing, no secondary debuiking is necessary. The perforator flaps can be chosen as the first option to deal with superficial extremity wounds.

Surgery of hip fracture in elderly patients aged equal or greater than 80 years old / 中国医师进修杂志

Objective To explore the outcomes of surgery of hip fracture in elderly pafienta aged equal or greater than 80 years old.Method The data of totally 132 patients with hip fracture aged equal or greater than 80 years old were treated with surgery between January 2004 and December 2008 was analyzed retrospectively Results Of 132 cases,68 cases were femoral neck fracture,while 64 cases were intertroehanteric fracture.The average in.hospital time waft(17.2±4.6)d,and 2 cases died of cerebral embolism and respiratory dysfunction in perioperative period respectively.One hundred and eight cases were followed up for 6 months to 5 yeats,with an average of 3.2 years.According to Harris hip scores,the average score of femoral neck fracture at 1 year and at 2 years postoperatively were(77.6±10.2),(77.3±9.3)scores,respectively;while intertrochantefic fracture at 1 year and at 2 years postoperatively were(84.6±9.8),(83.9±10.1)scores,respectively.Conclusions Aged patients with hip fracture should receivesurgical treatment as early as possible.The reasonable perioperative treatment and operative method are the keys to gain good outcomes.

Correlation of synovial fluid and articular cartilage osteopontin with disease severity in knee osteoarthritis / 中华骨科杂志

Objective To examine osteopontin (OPN) levels in both synovial fluid and articular cartilage of patients with primary knee osteoarthritis (OA) and to investigate their relationship with severity of the disease. Methods Fifty patients with knee OA and 10 healthy controls were enrolled in this study.There were 15 males and 35 females with an average age of 61.8±7.4 years in OA group. The control group included 4 males and 6 females with an average age of 63.2±6.0 years. Mankin score were taken to determine the disease severity of the affected knee. The radiographic grading of OA in the knee was performed using the Kellgren-Lawrence criteria. OPN levels in synovial fluid were measured using enzyme-linked immunosorbent assay. OPN levels in articular cartilage were assessed by immunohistochemical methods. Results Compared to healthy controls, the knee OA patients had higher OPN concentration in synovial fluid ([4519.60±1830.37] pg/ml vs. [1179.70±303.39] pg/ml) and articular cartilage([0.60±0.06] vs. [0.43 ±0.07]). In addition, synovial fluid OPN levels showed a positive correlation with articular cartilage OPN levels (r=0.411,P=0.003). Subsequent analysis showed that the OPN levels in synovial fluid significantly had been correlated with severity of disease using Kellgren-Lawrence criteria (r=0.581, P＜ 0.001). Furthermore,the levels of OPN in the articular cartilage also were correlated with disease severity using Mankin score (r=0.675, P＜ 0.001).Conclusion The data suggest that OPN in synovial fluid and articular cartilage is related to progressive joint damage and could be a predictive biomarker respect to disease severity and progression in knee OA.

Anatomic characteristics and clinic significance of the medial calcaneal nerve / 中南大学学报(医学版)

OBJECTIVE@#To provide anatomic evidence for choosing medial calcaneal nerve(MCN ) as recipient cutaneous nerve to rebuild heel sensation.@*METHODS@#We chose 20 adult cadavers' lower limbs, dissected the MCNs, observed their original sites, shapes, courses and distribution, and measured the perpendicular distance from original sites of MCNs from tibial nerve, original sites of their branches to the tip of medial malleolus, and the external diameters of their main trunks and branches.@*RESULTS@#The frequency of the MCN was 95% in this array. All the MCNs arose from the tibial nerve at 3.3 cm up the horizontal plane of the tip of medial malleolus. They sent out anterior branches and posterior branches from 0.3 cm below the horizontal plane of the tip of medial malleolus on average. The anterior branch dominated the cutaneous sensation of the anterior part of the medial calcaneal and heel weight loading field, while the posterior branch dominated the sensation of the posterior and median part. The shape of MCNs, main trunks, anterior branches and posterior branches was like circular cylinder. At the origination, the external diameter of the MCN, the anterior branch and the posterior branch was 1.58, 1.13 and 0.90 mm on average, respectively.@*CONCLUSION@#The anatomical position of MCN is relatively constant, and its external diameter is suitable. The initiation is not close to the heel weight loading area. Its anatomic characteristics meet the requirements of sensation recovery of the heel, especially the heel weight loading field.

Treatment of Tile B pelvic fracture by external fixator combined with limited internal fixation / 中南大学学报(医学版)

OBJECTIVE@#To determine the effectiveness of external fixator combined with limited internal fixation for Tile B pelvic fractures.@*METHODS@#Fourteen patients with Tile B pelvic fracture were treated by external fixator combined with limited internal fixation between September 2004 and June 2009.@*RESULTS@#All the patients were followed for 6-49 (20.2 +/- 10.2) months. According to the Matta standard, the outcome of 9 patients was excellent, 4 patients were good, while the other one patient was fair.@*CONCLUSION@#External fixator combined with limited internal fixation is effective for Tile B pelvic fracture. It can not only reduce the anatomic position of the pelvis, but also strengthen the stability of the pelvis as a whole. This method is less invasive and traumatic, which promotes the recovery of patients.

Effect of anterior cruciate ligament rupture on the strain of medial collateral ligament / 中南大学学报(医学版)

Objective To explore the effect of anterior cruciate ligament (ACL) rupture on the biomechanics of medial collateral ligament (MCL). Methods Six fresh human knee joints were fixed on the self-made fixture and flexed 90°. ACL was divided into a normal group, an anteromedi-al bundle(AMB) break group, and an ACL complete break group. 800N burden was loaded, and the MCL strain data were compared among the 3 groups. Results The MCL strain was significantly increased in the AMB break group and the ACL complete break group than that in the normal group (P<0.05). There was no significant difference in the MCL strain between the AMB break group and the ACL complete break group (P>0.05). Conclusion ACL rupture may cause significant changes in the MCL biomechanics, but the effect of AMB break and ACL complete break on MCL has no significant difference.

Effect of abducens orthosis combined with walker on developmental dysplasia of the hip / 中南大学学报(医学版)

Objective To evaluate the effect of abducens orthosis combined with walker on de-velopmental dysplasia of the hip ( DDH ). Methods A total of 126 patients (224 hips ) with DDH aged 6～36 months in Xiangya Hospital was randomly divided into 2 groups: an orthosis combined with walker group and an improved hip frog cast fixation group. Seventy patients (130 hips) were treated by the orthosis combined with walker and 56 patients (94 hips) were treated by the improved hip frog cast fixation. We compared the effect and complications of the 2 groups. Results The fine-ness rates of the orthosis combined with walker group and the improved hip frog cast fixation group were 89.2% and 90.4% , respectively, with no significant difference (P>0.05). The rate of femoral head osteonecrosis in the orthosis combined with walker group was significantly lower than that in the improved hip frog cast fixation group (1.5 % vs. 5.3 % , P<0.05) , but the re-dislocation rate in the former was significantly higher than that in the latter (6.9 % vs. 1.1% , P<0.05). Conclusion Both methods are effective for DDH. Orthosis combined with walker has a lower propor-tion of femoral head osteonecrosis, but a higher proportion of re-dislocation.

Effect of low-intensity pulsed ultrasound stimulation on maturation of regenerate bone / 中南大学学报(医学版)

Objective To explore the effect of low intensity pulsed ultrasound stimulation (LI-PUS) on the maturation of regenerate bone in a rabbit limb lengthening model. Methods Sixty skeletal mature female New Zealand white rabbits were randomly divided into an LIPUS treatment group and a control group. All rabbits were underwent mid-diaphyseal tibial osteotomy and immobilized in an Orthofix M103 Mini lengther. Gradual distraction at 0. 5 mm every 12 h for 10 d was performed at day 7 postoperatively. A 4-week course of LIPUS treatment group was applied over the distraction site for 20 min daily starting immediately after the completion of the distraction only for the treatment group. Rabbits were euthanized and the mid-diaphyseal tibia was harvested for evaluation at 4, 8, and 12 wk after the completion of the bone lengthening protocol. Radiographic analysis was performed to study the formation of bone callus using the ImageJ software at 12 wk after the completion of the bone lengthening protocol. Bone mineral density (BMD) of regenerate bone was measured by Dual energy X-ray absorptiometry (DEXA) . Torsional testing to failure was performed on the tibia specimens at 8 and 12 wk after the completion of the bone lengthening protocol. Results Radio-graphic measurement showed higher relative gray scale of bone callus in the LIPUS group than that in the control group at 12 wk (P ＜ 0. 05) . BMD in the LIPUS group was significantly higher than that in control group at 8 and 12 wk (P ＜ 0. 05). Biomechanical testing showed that the ultimate torque, ultimate torsional stiffness, and energy absorption at failure of regenerated bone at 8 and 12 wk in the LIPUS treatment group were better than those in the control group (P ＜ 0. 05) Conclusion LIPUS as a biophysical stimulation may accelerate the formation and maturation of regenerate bone in rabbit tibia lengthening model.