Biomechanical advantages of medial support screws in locking plate for treating proximal humerus fractures / 医用生物力学

Objective To evaluate the biomechanical advantages of medial support screws (MSSs) in locking proximal humeral plate for treating proximal humerus fractures. Methods Thirty synthetic left humeri were randomly divided into 3 groups to establish the fracture models. Group A was fixed with a locking proximal humerus plate with medial cortical support, but without MSSs; group B was fixed with 3 MSSs, but without medial cortical support; group C was fixed with neither medial cortical support nor MSSs. Axial compression, torsion, shear stiffness and failure tests were applied on the specimens of the three groups. Results For axial compression tests, the maximum load of group A, B, C was (240.88±19.13), (169.04±19.26), (128.58±17.53) N, respectively; the axial stiffness of group A, B, C was (424.4±101.2), (230.7±40.54), (147.0±29.2) N/mm, respectively, showing significant differences (P0.05). For shear stiffness tests, the maximum load of group A, B, C was (444.71±20.87), (228.79±28.95), (188.73±26.15) N, respectively; the shear stiffness of group A, B, C was (70.0± 54.4), (183.89±29.64), (140.2±32.1) N/mm, respectively, showing significant differences (P0.05). Conclusions Using three MSSs in locking plate for proximal humerus fractures shows optimal biomechanical properties, as compared to the situation without restoration of the medial column support. The reconstruction of the medial cortical support or MSSs for proximal humerus fractures helps to enhance the mechanical stability of the humeral head and prevent failure after internal fixation.

Finite element analysis on titanium elastic nail and reconstruction plate fixation for midshaft clavicular fractures / 医用生物力学

Objective To analyze the stress distribution and peak stress on midshaft clavicular fractures fixed by titanium elastic nail (TEN) or reconstruction plate, respectively. Methods CT data of the clavicle was adopted to reconstruct the intact clavicle model and the midshaft clavicular fracture models with the TEN and reconstruction plate fixation by using Mimics software. All the three dimensional finite element models were analyzed using Abaqus 6.9 software. The distal displacement, the peak stress and stress distribution on the distal clavicle under the axial load (250 N) and vertical load (250 N) were calculated for the three models. Results The axial displacement of the distal clavicle under the axial load showed TEN (0.23 mm)>intact clavicle (0.14 mm)>reconstruction plate (0.11 mm), respectively. While the vertical displacement of the distal clavicle under the vertical load was 5.12 mm for TEN, 3.71 mm for intact clavicle and 2.25 mm for reconstruction plate, respectively. But the peak stress of the clavicle under the axial load was 33.1 MPa for TEN, 18.7 MPa for reconstruction plate, and 15.5 MPa for intact clavicle model, respectively. And the peak stress under the vertical load was 146.3, 64.1, 56.1 MPa in the TEN, intact clavicle model, and reconstruction plate model, respectively. The stress distribution in TEN model under both kinds of loads was similar to that in intact clavicle model, while under the vertical load, the stress distribution in reconstruction plate model was clearly different with that in intact clavicle model. For the implants under the axial load, the peak stresses were 191.5, 52.3 MPa in the TEN model and reconstruction plate model, respectively, and the peak stress on implants under the vertical load was 1 248.0, 421.7 MPa in the TEN model and reconstruction plate model, respectively. Conclusions The TEN for treating midshaft clavicular fractures showed a stress distribution similar to the intact clavicle, with a higher peak stress and a higher peak implant stress at the fracture site. The reconstruction plate fixation for midshaft clavicular fractures was shown to be more stable, but with obvious stress shielding. Therefore, TEN is generally preferable for treating the simple displaced fractures of midshaft clavicle. However, the ipsilateral shoulder should avoid excessive exercise and weight bearing in the early postoperative period.

Transfection of exogenous gene: Lac Z into spinal cord of SD rats and its protein expression:an in vivo study / 中国骨伤

<p><b>OBJECTIVE</b>To explore a way of the gene therapy for acute spinal cord injury (ASCI) by vivo transfection of exogenous gene into spinal cord tissue.</p><p><b>METHODS</b>Twenty-four rats of SD were divided into experiment group and control group (each group had 12 rats). After anaesthesia by abdominal cavity, lamina of thoracic vertebra of all rats were cut-open in prone position. Complex of plasmid and report gene-Lac Z, and plasmid without report gene-Lac Z were respectively injected into cavum subdural of SD rats of experiment group and control group by cation liposome (DOTAP) encapsulation. The rats were killed at the 2nd week after operation, spinal cord tissue of injected segments were detected by reverse transcription-polymerase chain raction (RT-PCR) and immunohistochemistry.</p><p><b>RESULTS</b>In experiment group, positive staining of beta-galactosidase can be clearly observed in neuron and glia cell of rat's spinal cord by immunohistochemistry detection. Lac Z mRNA in same area was also detected by RT-PCR. But, in control group, no above-mentioned positive results were found.</p><p><b>CONCLUSION</b>Effective transfection of exogenous gene in vivo into spinal cord is a new hot spot for treatment of SCI. Thus certain nerve growth factor imput partly area of spinal cord injury can promote central nerve regrowth and avoid early secondary injury.</p>

Surgical treatment of tarsometatarsal joint complex injury / 中华外科杂志

<p><b>OBJECTIVE</b>To report the outcome of surgical treatment of tarsometatarsal joint complex injury.</p><p><b>METHODS</b>In the period from January 2003 to December 2008, 167 cases of closed tarsometatarsal joint injury were treated, including 35 cases of tarsometatarsal joint complex injury. Diagnosis was made by X-ray examination or/and CT scan. Either close or open reduction was performed and followed by internal fixation with screw or/and plate. X-ray examination was done in the regular follow-up and functional evaluation was carried out by AOFAS midfoot score system.</p><p><b>RESULTS</b>In this series 135 cases got a mean follow-up of 48 months, ranging from 12 to 75 months. Therein the 26 cases of tarsometatarsal joint complex injury had a mean postoperative AOFAS midfoot score of 67 (ranging from 48 to 75), and secondary post-traumatic arthritis in 16 cases, 12 of which had arthrodesis as a result of severe pain. The 109 cases of pure tarsometatarsal joint injury had a mean postoperative AOFAS midfoot score of 82 (ranging from 70 to 95), and secondary post-traumatic arthritis in 17 cases, only 5 of which had arthrodesis finally. Those cases of pure tarsometatarsal joint injury treated by close reduction and internal fixation with percutaneous screw got a mean postoperative AOFAS midfoot score of 87 (ranging from 82 to 95), demonstrating a significant deference (t = 2.651, P < 0.05) when compared with that of metatarsal joint complex injury.</p><p><b>CONCLUSION</b>The tarsometatarsal joint complex injury has a prognosis inferior to that of the pure tarsometatarsal joint injury, and the keys to its successful treatment are appropriate diagnosis, anatomical reduction and secure fixation of all the components of the complex.</p>

Clinical application of the reverse neurocutaneous flap with anterior cutaneous branch of the femoral nerve supplied by the perforator of saphenous artery / 中华整形外科杂志

<p><b>OBJECTIVE</b>To report the operative technique and clinical application of the neurocutaneous flap with anterior cutaneous branch of the femoral nerve supplied by the perforator of saphenous artery.</p><p><b>METHODS</b>The reverse neurocutaneous flap with anterior cutaneous branch of the femoral nerve supplied by the perforator of saphenous artery was used for repairing the defect around knee or at the upper pad of leg. Since Oct. 2005, 16 cases were treated. The flap size ranged from 15 cm x 7 cm to 30 cm x 15 cm. Flap rotation angle ranged from l00 degrees to 180 degrees.</p><p><b>RESULTS</b>13 flaps survived completely. Flap necrosis happened at the 1/7 - 1/5 distal end of the 3 flaps, which healed with dressing or local flap advancement. The patients were followed up for 6 to 24 months with satisfactory functional and cosmetic results. There was no morbidity at the donor site.</p><p><b>CONCLUSION</b>The flap has the advantages of both the perforator flap and the neurocutaneous flap. The size of the neurocutaneous flap with the anterior cutaneous branch of the femoral nerve can be enlarged for the large defect at lower extremity.</p>

Locally administered lentivirus-mediated siRNA inhibits wear debris-induced inflammation / 中华外科杂志

<p><b>OBJECTIVE</b>To determine the safety and efficacy of local administration of lentivirus-mediated small interfering RNA (siRNA) targeting tumor necrosis factor-alpha (TNF-alpha) in murine air pouch model.</p><p><b>METHODS</b>From May 2007 to April 2008 a siRNA targeting TNF-alpha and a missense siRNA were designed, and recombine lentivirus which coexpressed the green fluorescent protein (GFP) as a marker gene was constructed. Air pouches were established and stimulated by Ti-6Al-4V particles. Pouches were divided into 3 groups randomly. Lentivirus-mediated siRNA targeting TNF-alpha (TNF-alpha group) or lentivirus-mediated missense siRNA (MS group), or virus-free saline (control group) were injected into pouches respectively. Pouch membrane, peripheral blood, heart, liver, spleen, kidney, lung and brain were harvested at 28 d after transfection, and assayed for markers of inflammation using histological, molecular, immunological techniques and Xenogen in vivo imaging system (IVIS) 50 vivo bioluminescent assay system.</p><p><b>RESULTS</b>Xenogen IVIS 50 vivo image revealed strong expression of GFP localized in pouch areas and no expression in other parts of mice both in TNF-alpha group and MS group at 4 weeks after transfection, while no expression of GFP was found in control group. By RT-PCR and ELISA, the mRNA and protein levels of TNF-alpha in TNF-alpha group decreased by 81.6% and 82.6% respectively compared to control group (P < 0.01), and decreased by 78.9% and 84.0% respectively compared to MS group (P < 0.01), whereas TNF-alpha level in peripheral blood, heart, liver, spleen, kidney, lung and brain remained invariant (P > 0.05). Less inflammatory responses (thinner pouch membrane and decreased cellular infiltration) were observed in TNF-alpha group.</p><p><b>CONCLUSION</b>Efficient local delivery of lentivirus-mediated siRNA targeting TNF-alpha into modified murine air pouch can inhibit debris-induced inflammation effectively, with no systemic adverse effects.</p>

Treatment of old femoral neck and nonunion with free vascularized fibular grafting / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the clinical result of the treatment of old femoral neck fracture and nonunion with free vascularized fibular grafting.</p><p><b>METHODS</b>From November 2000 to December 2005, 29 cases with old femoral neck fracture and nonunion had been treated by free vascularized fibular grafting with an average follow-up of 28.5 months.</p><p><b>RESULTS</b>All the fracture were healed without any severe complications. And the healing time was 4-6 months (5.6 months on average). During the follow-up, the hips of 28 cases got well-function, and the average Harris hip score was 88.2. One case came about with osteonecrosis of femoral head after one year and finally accepted THA after 2 years.</p><p><b>CONCLUSIONS</b>The free vascularized fibular grafting is a valuable procedure to treat old femoral neck fracture and nonunion.</p>

The surgical technique and follow-up of the treatment with locking internal fixation on long bone nonunion of extremities / 中华外科杂志

<p><b>OBJECTIVE</b>To report the outcome of long bone nonunion of humerus, femur and tibia treated with locking internal fixation and bone graft.</p><p><b>METHODS</b>From February 2003 to October 2006, locking internal fixation and bone grafting were employed to treat 5 cases at humerus, 33 cases at femur, 23 cases at tibia. Forty-four of the patients were men, and 17 were women. The mean age was 38 years (range 7-70 years). The nonunion had resulted from failure of internal fixation in 47 cases, failure of external fixation in 5 cases, infection in 9 cases. The history of nonunion lasted from 10 to 156 months (mean 19 months). There were 42 patients treated with locking compression plate (LCP), and 19 patients with less invasive stabilization system (LISS). For bone grafting, autogenous ilium was used in 55 patients, autogenous ilium and allograft bone was used in 3 patients, allograft bone and Wright DBM artificial bone was used in 3 patients.</p><p><b>RESULTS</b>All the 61 patients were followed up for an average 12 months (range 6-24 months) only to reveal solid bone union in all the fracture, with a mean healing time of 4.8 months (ranged from 4 to 6 months). No loosening or breakage of the implants occurred in this series. The Knee Society Scores (KSS) was used to evaluate knee function in 47 patients with peri-knee joint nonunion, excellent result were seen in 35 patients, good in 7 patients, fare in 1 patients, poor in 4 patients.</p><p><b>CONCLUSION</b>Locking internal fixation can be used to treat effectively bone nonunion at the humerus, femur and tibia.</p>

Reverse first dorsal metatarsal artery island flap for coverage of donor defect of great toe after free lateral pulp flap transfer / 中华整形外科杂志

<p><b>OBJECTIVE</b>To employ reverse first dorsal metatarsal artery island flap to recover the donor site of great toe after free lateral pulp flap transfer, and decrease the morbidity of microsurgical donor site.</p><p><b>METHODS</b>From February 2000 to June 2004, 12 cases of soft tissue defect in thumb and finger were treated by free lateral pulp flap of great toe transplantation, and that the secondary defect of great toes were repaired by reverse first dorsal metatarsal artery flap according to the anatomical communicating between first dorsal metatarsal artery and plantar metatarsal artery. The donor exposure of dorsal pedis were straightly sutured.</p><p><b>RESULTS</b>All the lateral pulp flaps of great toe and the reversed first dorsal metatarsal flaps survived uneventfully with desirable appearance and sensation. In thumb and finger defect reconstructed with lateral pulp flaps of the great toe, there was in mean static two-point discrimination of 6 mm at 10 month follow-up, that was 10 mm in reverse flaps.</p><p><b>CONCLUSIONS</b>It is an instructive and practical creation to adopt the reverse first dorsal metatarsal artery flap to recover the raw surface in the lateral aspect of the great toe, which minimizes the morbidity at the donor site and gains the twin-win results.</p>

Minimally invasive two-incision total hip arthroplasty: a short-term retrospective report of 27 cases / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Total hip arthroplasty (THA) is widely applied for the treatment of end-stage painful hip arthrosis. Traditional THA needed a long incision and caused significant soft tissue trauma. Patients usually required long recovery time after the operation. In this research we aimed to study the feasibility and clinical outcomes of minimally invasive two-incision THA.</p><p><b>METHODS</b>From February 2004 to March 2005, 27 patients, 12 males and 15 females with a mean age of 71 years (55 - 76), underwent minimally invasive two-incision THA in our department. The patients included 9 cases of osteoarthritis, 10 cases of osteonecrosis, and 8 cases of femoral neck fracture. The operations were done with VerSys cementless prosthesis and minimally invasive instruments from Zimmer China. Operation time, blood loss, length of incision, postoperative hospital stay, and complications were observed.</p><p><b>RESULTS</b>The mean operation time was 90 minutes (80 - 170 min). The mean blood loss was 260 ml (170 - 450 ml) and blood transfusion was carried out in 4 cases of femoral neck fracture (average 400 ml). The average length of the anterior incision was 5.0 cm (4.6 - 6.5 cm) and of the posterior incision 3.7 cm (3.0 - 4.2 cm). All of the patients were ambulant the day after surgery. Nineteen patients were discharged 5 days post-operatively and 8 patients 7 days post-operatively. The patients were followed for 18 months (13 - 25 months). One patient was complicated by a proximal femoral fracture intraoperatively. No other complications, including infections, dislocations, and vascular injuries, occurred. The mean Harris score was 94.5 (92 - 96).</p><p><b>CONCLUSIONS</b>Two-incision THA has the advantage of being muscle sparing and minimally invasive with less blood loss and rapid recovery. However, this technique is time consuming, technically demanding, and requires fluoroscopy.</p>

Effect of tension on force of contraction of muscle and nerve conduction velocity of the repaired nerve in a rat model.

To investigate the effect of tension on the contractive force of muscle and nerve conduction velocity of the repaired nerve, this study was designed. Fifty-four Sprague-Dawley (SD) rats were randomly divided into 3 groups. The left gastrocnemius muscles of the rats were dissected with the neurovascular pedicles intact; the tibial nerves were cut and immediately repaired by epineurial suture. Then the Achilles tendons were isolated and treated accordingly; the Achilles tendon was lengthened by 0.5 cm in lengthened group, shortened by 0.5 cm in shortened group and left alone in normal (control) group. In the 2nd, 4th and 8th weeks after operation, the isometric twitch contractive force of both the right and the left gastrocnemius muscles and the nerve conduction velocity (NCV) of the tibial nerve were measured. The shortened group showed greater isometric twitch contractive strength of the bilateral gastrocnemius muscles than those in the normal and lengthened groups in all the postoperative periods. The nerve conduction velocity (NCV) in the shortened group showed greater than other groups. A proper high tension of the muscle can increase the contraction of the muscle and may improve the nerve conduction velocity of the repaired nerve.

Application of vascularized free tissue transplantation in emergency repair of traumatized limbs:report of 86 cases / 中华显微外科杂志

Objective To report the outcome of emergency repair traumatized limbs by vascularized free tissue transplantation.Methods From April 1988 to August 2004,86 patients,58 men and 28 women,had undergone emergency vascularized free tissue transplantation to have their injured limbs repaired in 54 cases and the missing thumbs reconstructed in 32.The patients aged from 5 to 55 (mean 27.9) years. The transplants included latissimus dorsi myocutaneons flap,anterolateral femoral skin flap,medial crural skin flaps,dorsal pedal flaps,medial plantar flap,composite tissue mass of the discarded limbs and big toe skin- nail flap.The operations were performed 1 to 5 days after injuries.Results Postoperative vascular crises occurred in 8 cases and were all followed by exploration with successes in 5 cases while failure in 3.The total survival rate of the transplants was 96.5% (83/86).In this series all the patients were followed up for 1 to 16 years with a mean of 7.5 years only to reveal satisfying functional recovery in all the repaired limbs and an ex- cellent and good rate of 87.5% in the reconstructed thumbs.Conclusion Emergency vascularized free tis- sue transplantation is an effective way to repair a traumatized limb and to reconstruct a traumatically missing thumb.

Emergency reparation and reconstruction for complicated tissue defects in hand / 中华显微外科杂志

Objective To explore the operative methods and clinical outcomes in emergency or sube- mergency repair for the complicated tissue defects in hand in first stage applying microsurgical technique. Methods From Jan.,2000 to Aug.,2005,49 emergency cases of complicated hand tissue defects were re- paired in the first stage with replantation,reconstruction,free flaps,combined finger reconstruction and flap transplantation,including 21 cases in mini tissue mass replantation or reconstruction,15 cases in replantation combined with free flap transplantation,8 cases in replantation and reconstruction combined with free flap transplantation,5 cases in combined multiple digits reconstruction with free flap transplantation.The free flap transplantation included the anterolateral femoral flap,the latissimus dorsi myocutaneous flap,the dorsalis pe- dis flap,the media pedis flap and the instep flap.Results All the flaps,the replanted and reconstruceted finger survived uneventfully except for one replanted finger necrosis.45 cases healed in the first stage and the other 4 cases healed in the second stage.During a follow-up from 6 months to 3 years postoperatively,a satis- factory appearance and function of the reconstructed hand was achieved.The excellent and good rate was 85.7% assessed with provisional functional assessment criterion for upper limbs issued by Chinese Society of Hand Surgery.Conclusion The emergency or subemergency repair for the complicated tissue defects in hand has the advantage of short-term treatment and desirable functional outcome.The emergency replantation and reconstruction combined with various flaps or tissue mass can be applied to repair tissue defect in hand in the first stage according to the position and area of the defect along with the technique level of the surgeon, having been proved to achieve desirable clinical outcomes.And the key points leading to a successful operation is the correct treatment for the raw surface of the defects,suitable choice for various flaps,logical design of combination pattern and prevention and timely treatment for vessel crisis.

Ultrastructure of Vascularization During Osteogenesis by Tissue Engineering Technique / 上海第二医科大学学报

Objective To observe the changes of osteoblasts and vascularization during osteogenesis by tissue engineering technique under the electron microscope and study the feasibility of improving vascularization of the tissue engineering bone by using the small intestine submucosa(SIS) as the scaffold. Methods The bone mesenchymal stem cells(BMSCs) were isolated by using the gradient centrifuge method.BMSCs were seeded in the SIS.The scaffold-cell constructs were cultured in vitro for two weeks.There were no cells on the SIS as control.They were implanted subcutaneously in the dorsa of the athymic mice.The implants were harvested after(in vivo) incubation for 4,8 and 12 weeks.The changes of osteoblasts and vascularization were observed under the transmission electron microscope and the scanning electron microscope. Results The BMSCs grew quite well.BMSCs differentiated on the surface of the SIS and secreted a great deal of extracellular matrices.The scaffold-cell constructs formed a lot of bone and vessels in vivo.The scaffold degraded after 12 weeks.No osteoblasts but vascularization and fibroblasts were observed as control. Conclusion SIS can be used as the scaffold for constructing tissue engineering bone as it can improve the formation of bone and vessels in vivo.

Experimental study on callus calcification and mechanical property of healing bone under low frequency and controlled micromovement / 上海第二医科大学学报

Objective To investigate the effects of external fixator with dynamic device under low frequency and controlled micromovement on the callus calcification and mechanical property of healing bone.MethodsForty-five sheep were performed transverse osteotomy with a gap of 2 mm on the mid-shafts of both tibias,and the hind limbs were fixed with unilateral external fixators connected to a controlled micromovement device.Ten days after osteotomy,one hind limb of each sheep was randomly selected for micromovement(30 min/d).According to different micromovement frequencies,the sheep were randomly divided into 3 groups: 0.5 Hz group,1 Hz group and 5 Hz group(n=15).The amplitude of micromovement was 0.25 mm and the micromovement stopped by the end of the fourth week postoperation.The other hind limb of each sheep was served as control group without micromovement.Morphometry of callus was done at the end of 4,6 and 9 weeks after osteotomy.Bone formation velocity,bone mineral density and biomechanical properties were compared at the end of 9 weeks.Results The areas of mineralized bone and osteoid in different miromovement groups were larger than that of control group at the end of 4,6 weeks postoperation(P

Optimal timing of fixation for femoral shaft fractures with concomitant head injuries / 上海第二医科大学学报

Objective To discuss the optimal timing of fixation for femoral shaft fractures with concomitant head injuries. MethodsEarly and delayed complications,mortality rate,interval of ICU and duration of hospital stay were compared among 137 patients with head injuries,so as to evaluate the curative effect of early fixation of femoral shaft fracture(n=56) and delayed fixation(n=81).Results Early fixation group enjoyed advantages in the interval of ICU,duration of hospital stay,associated shock and infection rate over the delayed fixation group(P

Arthroscopically assisted treatment of tibial plateau fractures by tractive reduction with external fixator / 中华外科杂志

<p><b>OBJECTIVE</b>To study the clinical effect of tractive reduction with external fixator and arthroscopically assisted treatment for tibial plateau fractures.</p><p><b>METHODS</b>From February 2003 to January 2005, a total of 26 cases with tibial plateau fractures were reviewed. There were 4 cases of type I fracture, 5 type II, 4 type III, 6 type IV, 5 type V and 2 type VI based on Schatzker criteria. Before operation, X-ray examination and CT scanning were done. During operation, the dissociative fragments were reconstructed by tractive reduction with external fixator arthroscopically and fixated with screws or plates.</p><p><b>RESULTS</b>All the fractures were healed within 1.5 - 4 months, with no severe complications such as poor wound healing, infection or osteofascial compartment syndrome. All patients that were followed up for 7 - 21 months (mean, 16 months) showed no traumatic osteoarthritis, inversion or eversion of the knee. According to the Rasmussen scoring system, the outcome was excellent in 11 cases, good in 13 and fair in 2, with total score of 27 +/- 2.</p><p><b>CONCLUSIONS</b>As for Schatzker type I - VI tibial plateau fractures, tractive reduction with external fixator and arthroscopically assisted treatment is characterized by minimal invasion, fast fracture healing. It broadens operative interspace of articular cavity, improves accuracy of reduction, is beneficial for knee joint function to recover.</p>

Minimally invasive total hip arthroplasty with anterior incision / 中华外科杂志

<p><b>OBJECTIVE</b>To report the clinical outcome of minimally invasive total hip arthroplasty with anterior incision.</p><p><b>METHODS</b>One hundred and twenty cases were randomly divided into two groups. Sixty cases (group 1) who had undergone a mini-invasive THA were compared with 60 cases (group 2) who had undergone THA with standard posterolateral incision. The operation time, length of incision, blood loss, anteversion angle of acetabulum cup, Harris score and complications were observed.</p><p><b>RESULT</b>The average operation time was almost the same; The average length of incision for group 1 was 7.9 cm (7.4 - 9.0 cm) and 16.3 cm (14 - 22 cm) for group 2 (P < 0.01). The average blood loss for group 1 was 350 ml (250 - 530 ml) and 650 ml (400 - 1200 ml) for group 2, there was significant difference between two groups (P < 0.05). According to the postoperative X-ray, the mean anteversion angles of cup were 24 degrees (19 degrees - 27 degrees) for group 1 and 19 degrees (15 degrees - 22 degrees) for group 2. The average length of post-operative hospital stay was 7 days (5 - 8 days) in group 1 and 13.5 days (12 - 16 days) in group 2 (P < 0.05). The Harris score of group 1 was 91.4 (67 - 94) and 78.5 (67 - 91) for group 2 at the 3 month follow-up (P < 0.05). At the last follow up, there were no significant difference (P > 0.05), but the average ROM of group 1 were definitely more greater than that of group 2 (110.0 degrees +/- 3.2 degrees vs. 90.0 degrees +/- 2.9 degrees P < 0.05). There was 1 case of cup reinsertion in group 1 because of large anteversion angle; 2 cases of symptomatic DVT and 1 case of lethargy because of cerebral infarction happened in group 2.</p><p><b>CONCLUSIONS</b>Minimally invasive total hip arthroplasty using anterior approach is a safe and effective technique with the advantages of less soft tissue damage and less blood loss.</p>

Periosteum construction in vitro by small intestinal submucosa combined with bone marrow mesenchymal stem cell / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the practicability of periosteum construction in vitro by small intestinal submucosa (SIS) as a tissue scaffold with bone marrow mesenchymal stem cells (BMSC).</p><p><b>METHODS</b>The bone marrow mesenchymal stem cells were cultivated by the conventional method in vitro, and then co-cultivated with SIS. The morphological feature of the complex material, the extracellular matrices, the adhesion and proliferation of BMSC were observed by optical microscope, electronic microscope, scanning electronic microscope and histologic evaluation respectively.</p><p><b>RESULTS</b>BMSCs adhered and proliferated on SIS, secreted a great deal of extracellular matrices with active cellular function. BMSCs grew well there in layers, and the thickness became thicker as time passed, acting like a biological periosteum.</p><p><b>CONCLUSION</b>Combined culture of SIS and BMSC in vitro can construct a tissue engineering periosteum similar to the natural one, thus providing a base for further study of its osteogenic regeneration in vivo.</p>

Prognostic significance of p21(WAF1) expression in osteosarcoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the expression of p21(WAF1) gene in human osteosarcoma and their relationships with clinicopathological parameters and prognostic value.</p><p><b>METHODS</b>The p21(WAF1) gene mRNA and p21 protein expression in 45 osteosarcoma and 10 fibrous dysplasia of bone specimens were analyzed by in situ hybridization and immunohistochemistry respectively.</p><p><b>RESULTS</b>(1) The positive rate of p21 protein expression in osteosarcoma was 17.7% (8/45). (2) The expression rate in high proliferation (4/10) significantly higher than that in low proliferation (4/35) osteosarcoma (chi2 = 4.34, P < 0.05). (3) The positive rate of p21(WAF1) mRNA expression in osteosarcoma was 42.2% (19/45). The expression rate in high proliferation (6/10) significantly higher than that in low proliferation (13/35) osteosarcoma (chi2 = 20.6, P < 0.01). (4) The survival time after operation of the patients with p21(WAF1) mRNA expression were higher than that of the patients with p21(WAF1) mRNA negative expression (P < 0.05).</p><p><b>CONCLUSIONS</b>(1) With the increase in degree of malignancy, the expression of p21(WAF1) mRNA and p21 protein in osteosarcoma tend decrease. (2) The expression of p21(WAF1) mRNA has a definite value in judging prognosis in osteosarcoma.</p>