BACKGROUND:At present, an increasing number of bone graft materials are inactivated using peracetic acid-ethanol solution, but there is no report on whether virus inactivation using peracetic acid-ethanol solution has effects on osteogenic induction of demineralized bone matrix. OBJECTIVE: To explore the effects of virus inactivation using peracetic acid-ethanol solution on the osteogenic activity of demineralized bone matrix. METHODS: Long bones of Sprauge-Dawley rats were selected to make demineralized bone matrix meal. A part of bone meal was placed into gelatin capsules and sterilized by60Coγ irradiation as control group; another part of bone meal was placed into gelatin capsules folowing virus inactivation using peracetic acid-ethanol solution, and then sterilized using60Coγ as experimental group. After that,40 Sprauge-Dawley rats were enroled, and gelatin capsules in the experimental and control groups were respectively implanted into the bilateral psoas muscles of the lumbar spine. At 2, 4, 6, 8 weeks after implantation, the bone grafts were removed for gross and histological observations. RESULTS AND CONCLUSION:At 8 weeks after implantation, the bone mass in the experimental group was not intact in shape with scattered particles, and under light microscope, a few of osteoblasts and new vessels were seen; the bone mass in the control group had hard texture and complete morphology, and under light microscope, mature bone trabeculae wrapped with osteoblasts and new vessels were visible and there were ful of fat cels and bone marrow cells between the bone trabeculae. The number of new microvessels in the experimental group was lower than that in the control group at different time (P < 0.001); at 8 weeks after implantation, the calcium content, alkaline phosphatase content, inorganic phosphorus content and new bone growth rate were all lower in the experimental group than the control group (P < 0.001). These findings indicate that peracetic acid-ethanol for virus inactivation has some negative effects on the osteogenic induction of demineralized bone matrix.

BACKGROUND:Mkx (Mohawk, transcription factor) is one of the crucial factors in tendon formation, development and differentiation.
OBJECTIVE:To summarize the molecular structure, distribution and function of Mkx and its research process in the signaling pathways during tendon differentiation.
METHODS:The first author retrieved the databases of CqVip, CNKI and Medline from1990 to 2016 using the keywords of“Mkx, Mohawk, Irxl, tendon, tendon differentiation, tissue engineering, TGFβ, stem cel”in Chinese and English, respectively. The articles related to research process of Mkx in tendon tissue engineering were retrieved, and a total of 55 literatures were enrol ed final y.
RESULTS AND CONCLUSION:Mkx that expresses in various mesoderm-derived tissues plays an important role in the formation and development of tendon and tissue-engineered tendon formation. Although Mkx does not directly act on Scx (Scleraxis), it can regulate the differentiation of tendon progenitor cel s via transforming growth factor-β2 signaling pathway. Cel s from different species and different cel lines as wel as various cytokines for certain make different effects on Mkx involved in tendon tissue engineering.

Objective To explore the therapeutic effect of total hip replacement (T HR) in treating osteonecrosis of the femoral head (ONFH) after failed internal fixation of femoral neck fracture .Methods From January 2003 to June 2012 ,32 cases (19 left hips and 13 right hips) of ONFH after failed internal fixation of femoral neck fracture were treated with THR .There were 18 males and 14 females with an age range from 35 to 62 years (mean ,50 .6 years) .The ONFH was diagnosed at 8-26 months (mean ,17 .1 months) after internal fixation ;the THR were conducted 15-48 months after first surgery (mean ,27 .2 months) .According to Fi‐cat classifi cation ,there were 8 cases at stage Ⅲ and 24 cases at stage IV .The Harris score was (40 .9 ± 9 .8) .The prosthesis of bi‐ology was used .Results All wounds healed by first intention .All cases were followed up for 6-48 months (mean ,28 .3 months) . The Harris score was (90 .8 ± 4 .4) at last follow‐up ,showing significant difference when compared with the preoperative value (P<0 .05) .The hip function were excellent in 25 hips ,good in 5 hips ,fair in 2 hip ,and the excellent and good rate was 93 .8% . There were 1 cases of periprosthetic femoral fracture(type C) ,2 cases of proximal femoral splitting fractures fractures .After corre‐sponding treatment ,fracture was healed in all cases .There were no complications (infection ,loosening dislocation or subsidence , etc) .Conclusion Total hip replacement is an effective method for the treatment of ONFH after failed internal fixation of femoral neck fracture .

BACKGROUND:Humeral supracondylar fracture is a common fracture occurred in children. The selection of internal fixation for humeral supracondylar fracture remains controversial. OBJECTIVE:To compare the biocompatibility between internal fixation with Kirschner wire and bioabsorbable implants for humeral supracondylar fractures. METHODS: From January 2007 to January 2013, 246 cases of humeral supracondylar fractures, from Affiliated Hospital of Luzhou Medical Colege, were treated by internal fixation with Kirschner wire. Meanwhile, the studies on internal fixation for treating supracondylar fracture of humerus in children were searched. Efficacy was evaluated by preoperative and postoperative elbow range of motion and the incidence of cubitus varus, and the results were statisticaly analyzed, and compared with other therapeutic methods. RESULTS AND CONCLUSION:Al cases were folowed up for 6-36 months, averagely 18 months. According to Mayo elbow performance score, function of the elbow joint was excelent in 194 cases, and good in 48 cases, with good and excelent rate being 98.4%. Four cases suffered < 5° cubitus varus, with incidence rate of 1.63%. The internal fixation with Kirschner wire provided functional recovery of elbow joint, but the second stage operation was needed to pick out the wires. And it might be perplexed by Kirschner wire loosening or needle withdrawal, resulting in instable fixation. Bioabsorbable implants were effective in the treatment of supracondylar fracture of humerus. Bioabsorbable sticks would break down over time, without harming to human body or influencing imaging examination. Elbow function development of the epiphysis would not be affected. However, due to lack of large-sample observation, long-term effects of bioabsorbable implants for treating supracondylar fracture of humerus in children deserve further studies.

Objective To discuss causation and clinical treatment of complication in anterior decompression and fixation technique (ADFT) for thoracolumbar fractures with associated paraplegia. Methods A total of 204 cases that had thoracolumbar fractures with paraplegia were operated with ADFT from 1998 to 2004. Of all, 51 times (34 cases) of complication took place. Change of Cob angle was measured according to X-film of thoracolumbar spine before and after operation. Meanwhile, sensation and motion of patients was evaluated. Results There was incision infection leading to septic cerebo-meningtis in one case, CSF leakage in seven, pneumothorax in eight, rib nerve-root injure in five, lumbar nerve-root injure in two, genitofemoral nerve injure in three, lateral femoral cutaneous nerve injure in two, kyphosis in three, deep venous thrombosis in three and eight times of skin-temperature change. X-film that was taken after operation for all patients showed scolisis in five cases. A follow up for 3-6 years (average 2.5 years) was performed in 84 cases, of which seven cases had chronic low-back pain, six scolisis and five kyphosis. No patient showed complications such as screw breakage, plate breakage, fixation device loosening and pseudo-articulation in thoracolumbar spine. Conclusions Many complications can be avoided if we master well anterior decompression and fixation technique of thoracolumbar fracture, reduce surgical trauma and give appropriate and rational guide for rehabilitation.

Objective To discuss basis and operative indications for anterior reversional indication after failures of posterior pedicel screw instrumentation for thorcolumbar burst fracture combined with paraplegia.Methods Clinical data of 21 cases who had failures of posterior pedical screw fixation because of thorcolumbar burst fracture combined with paraplegia were analyzed retrospectively from February 1999 to April 2005.All cases were operated by removing posterior screw device.Meanwhile,one stage anterior cord decompression,correction of kyphosis,fusion with self-ilium or Titanium cage with granule fractured vertebrate and internal fixation was carried out according to clinical symptom and image findings.Spinal cord function and correction of kyphosis were evaluated by Frankel score and Cob angle.Results All cases were operated successfully.After operation,there was rib nerve injury occurred in two cases,leakage of CSF in three and refractory thigh pain in two.The follow up ranging from three months to six years(average 2.2 years) showed good interfixation except for one case had breakage of screw four months after operation.Cob angle of kyphosis recovered from preoperative 16.4? to 5.2??0.3? at follow up.Of all,16 cases had partly recovery of spinal cord function according to Frankel score.(Conclusion)As for thoracolumbar burst fracture combined with paraplegia,anterior approach can attain direct decompression,satisfactory correction of kyphosis and stable fixation and is suitable for most cases.

BACKGROUND: The traditional treatment for skin donor site wound was focus on anti-infection and wound protection, which roof a long time for healing. Studies demonstrated that recombinant human epidermal growth factor (rhEGF) has accelerated effect or epidermal regeneration. OBJECTIVE: To observe the effect of rhEGF on wound healing of skin donor site. METHODS: A total of 32 cases needs wound healing by skin grafting were collected, including 18 males and 14 females. The 32 skin graft donor site wounds were randomly divided into control and treatment groups. In the treatment group, the absorbent gauze was sprinkle soaked with rhEGF (15 mL/ramus, 2 000 IU/mL) and covered the donor site, twice per day. In the control group, donor site was covered by physiological saline gauze and wrapped with dressing, twice per day. After 48 hours, semi-exposed therapy was performed. The healing time of wounds, the systemic and local adverse reactions of patients and blood routine examination and renal function detection prior to and after treatment were observed. RESULTS AND CONCLUSION: The healing time of wound in the rhEGF treatment group was shorter than that in the control group with significant differences (P < 0.01). No Adverse events or side effects were observed in the rhEGF treatment group. rhEGF can shorten wound healing time, reduce scar hyperplasia, and accelerate epithelization at the graft donor.

BACKGROUND:Accumulative evidence supports that vitreous cryopreservation can improve the cel survival rate. OBJECTIVE:To investigate the effect of vitreous cryopreservation on the tenocytes co-cultured with the porous polydimethylsiloxane (PDMS) scaffold. METHODS:Tenocytes were co-cultured with the porous PDMS scaffold for 9-14 days, and then preserved and resuscitated in the 10%dimethyl sulfoxide (DMSO), 21%DMSO and VS55, respectively. One hour later, the survival rate of post-resuscitated tenocytes versus pre-resusciated tenocytes was analyzed by live/dead double color fluorescent staining and flow cytometry. RESULTS AND CONCLUSION:Live/dead double color fluorescent staining revealed that tenocytes in the 10%DMSO group appeared to be irregular and double stained, and a large number of cel s shedding from the scaffold. The VS55 and 21%DMSO groups showed some spindle and hemispherical cel s single stained for green fluorescence and few double stained irregular cel s. Additional y, the cel density in the two groups was significantly lower than that in the control group. Flow cytometry results found that there were homogenous cel s in the control group;the number of cel s in the 10%DMSO group was too low to undergo flow cytometry;smal cel particles were visible in the VS55 group;in the 21%DMSO group, the cel volume was similar with the control group, and smal particles also existed. The survival rate in the VS55 group (64.9%) was significantly lower than that in the 21%DMSO group (76.2%;P<0.05). Conversely, the survived cel s were rare in the 10%DMSO group. To conclude, 21%DMSO vitreous cryopreservation improves the cel survival rate and is beneficial for tenocyte adherence to the scaffold.

BACKGROUND:The decel ularized porcine smal intestinal submucosa is a kind of bioactive extracel ular matrix, which is mainly composed of col agen, glycoprotein, proteoglycan and rich in col agen, glycosaminoglycan and various growth factors, and these components play an important role in promoting the differentiation and proliferation of tissue cel s. OBJECTIVE:To prepare the injectable smal intestinal submucosa and to investigate its co-culture with rat adipose-derived mesenchymal stem cel s in vitro. METHODS:The injectable smal intestinal submucosa and rat adipose-derived stem cel s were prepared. Cel counting kit-8 test for cel proliferation:Passage 3 adipose-derived stem cel s were seeded onto the injectable smal intestinal submucosa (experimental group) and cel s cultured under normal condition as control group. The cel proliferation was observed at 1, 3, 5 and 7 days of incubation. Live/dead staining test for the survival of cel s:Passage 3 adipose-derived stem cel s were respectively cultured in the injectable smal intestinal submucosa extracts (experimental group) and complete culture medium (control group). Cel survival was determined at 1, 3, 5 and 7 days of culture. RESULTS AND CONCLUSION:Scanning electron microscope oval and strip adipose-derived stem cel s adhered onto the material. The absorbance values in the experimental group were higher than those in the control group at 1 and 5 days of incubation (P<0.05). Cel survival:The number of cel s appeared to be in a rising trend with time in both two groups;after 1-day co-culture, al cel s in the two groups survived. Then dead cel s appeared in both two groups, showing no significant difference. These results show that the injectable smal intestinal submucosa exhibits a good cytocompatibility.

BACKGROUND:Legacy posterior stabilized prosthesis has advantages in theoretic design,in vitro kinematics and abrasion, but it remains unclear whether its clinical outcomes for vaglus knee deformity are better than Legacy constrained condylar knee prosthesis. OBJECTIVE:To explore the midterm folow-up effect of Legacy posterior stabilized prosthesis in total knee arthroplasty in patients with valgus knee deformity. METHODS: From February 2006 to November 2013 in Department of Bone and Joint Surgery, Affiliated Hospital of Luzhou Medical Colege, total knee arthroplasty was used to treat valgus knee deformity in 33 cases (35 knees). Parapatelar medial approach was used. Precise osteotomy was utilized to correct limb alignment. Lateral soft tissue received selective release. Finaly, an equal type of Legacy posterior stabilized prosthesis (Zimmer, USA) was implanted and fixed with antibiotic bone cement. The differences in hospital for special surgery knee score, range of motion of knee, femoral tibial angle, and maximum flexion and extension angle, as wel as X-ray film results were compared and analyzed before and after replacement. The complications including deep vein thrombosis, peri-prosthetic infection, patelar clicking, unstable knee, and common peroneal nerve injury were recorded after surgery. RESULTS AND CONCLUSION: Al patients were folowed up for 24-50 months. The incision was healed in one-stage. No complications such as peri-prosthetic infection appeared. Three patients suffered from common peroneal nerve palsy, which was cured at half a year after surgery by expectant treatment such as trophic nerve. Two cases suffered from knee instability after replacement, which was improved at 1 month after external fixation with a brace. One case experienced deep vein thrombosis in the lower extremity, which was improved after treatment with low molecular weight heparin anticoagulation. During final folow-up, hospital for special surgery knee score increased from (51.85±4.15) preoperatively to (85.77±2.50) postoperatively (P < 0.01). There were excelent in 20 knees, good in 11 knees, with an excelent and good rate of 89%. X-ray films showed that hindlimb alignment was apparently corrected, prosthetic position was good, no loosening occurred. These data indicate that total knee arthroplasty, using parapatelar medial approach, obtained good correction outcomes through the accurate amputation to correct hindlimb alignment and selective release of the soft tissue with Legacy posterior stabilized prosthesis in the treatment of valgus knee deformity.