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.

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: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.

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 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.

BACKGROUND:Considering the risk of lack of bone in revision and the bone coverage of component,it is advisable to use bone grafting to increase bone stock in patients with adult Crowe type Ⅲ developmental dysplasia of the hip (DDH) in the first total hip arthroplasty (THA).OBJECTIVE:To investigate the effectiveness of impaction bone grafting with morselized bone and bone paste for acetabular defects of adult Crowe type Ⅲ DDH in THA.METHODS:Forty cases (45 hips) of Crowe type Ⅲ DDH were enrolled,including 8 males and 32 females,aged 31-68 years.All the components were reconstructed at the anatomic acetabulum combined with deepening acetabulum and putting the centre of rotation medially and distally during THA procedures.The patients were all followed up and evaluated with Harris score,limp length,displacement of the centre of rotation,cup coverage,and postoperative complications.RESULTS AND CONCLUSION:The average follow-up was 32.7 months.Acetabular rotation centers of all the cases were recovered (near) to normal.The incisions healed by first intention and there was no complication such as infection,dislocation,prosthesis loosening.The acetabular cup prosthesis did not displace and was covered well by bone at the last follow-up,the grafted bone particles got radiological osseointegration and the bone sclerosis zone disappeared.No radiolucent lines and screw fracture were detected.The Harris scores of affected hips at the last follow-up were significantly higher than those before surgery(P=0).The average leg length was increased (2.31 ±0.18) cm.The mean cup coverage was 78.1％.The postoperative horizontal and vertical distance of the hip center were shorter than those before surgery (P=0).Reconstructing the acetabulum with autogenous morselized bone graft impaction can effectively restore the acetabular coverage,maintain the stability of acetabular cup and provide better relative bone stock in THA for Crowe type Ⅲ DDH in adult,and moreover,the short-term effect is satisfactory.

BACKGROUND: Hip-preserving treatment is advocated in the treatment of early avascular necrosis of the femoral head.OBJECTIVE: To compare the clinical efficacy of simple core decompression and three-dimensional porous core decompression combined with autologous bone marrow transplantation on early avascular necrosis of the femoral head.METHODS: Thirty patients (39 hips) with early avascular necrosis of the femoral head at phase I-II according to the staging criteria of the Association Research Circulation Osseuse (ARCO) who had been admitted to the First Affiliated Hospital of Luzhou Medical University between March 2011 and May 2016 were surgically treated and followed up.Seventeen patients (22 hips, trial group) were treated with three-dimensional porous core decompression combined with autologous bone marrow transplantation, including 10 cases of ARCO stage I and 12 cases of ARCO stage II; the other 13 patients (17 hips, control group) were treated with simple core decompression, including 7 cases of ARCO stage I and 10 cases of ARCO stage II. Harris scores, X-ray and magnetic resonance imaging were used to evaluate the surgical efficacy at 1, 3, 6, 9, 12, 18, 24, 30, 36 months after the operation.RESULTS AND CONCLUSION: The incision healed primarily in all patients, and no infection occurred. The follow-up lasted for 1-3 years (average 2.5 years). At the last follow-up, the Harris scores in both trial group and control group were significantly improved compared with the baseline (P < 0.05); moreover, the Harris scores of ARCO stage I and II patients were significantly higher in the trial group than the control group (P < 0.05). Collapse of the femoral head was observed in one hip (stage I) and one hip (stage II) of the trial group, and in three hips (stage I) and five hips (stage II) of the control group, and then hip arthroplasty was performed. The number of the patients developing collapse of the femoral head in the trial group was significantly less than that in the control group (P < 0.05). Compared with simple core decompression, three-dimensional porous core decompression combined with autologous bone marrow transplantation is more adept to improve patient's function and delay disease progression in the treatment of ARCO stage I and II early avascular necrosis of the femoral head.