Objective To observe the main biological characteristics and chondrogenesis potency of bone marrow -derived stromal cells(MSCs) after cytokinesinduction or gene modification in vitro. Methods MSCs from an adult New Zealand white rabbit were isolated and cultivated, and then MSCs were divided into the common medium group(Group A, 15%FBS in DMEM), the induced group by cytokines (Group B), the transfected group(Group C)with adenovirus-hepatocyte growth factor transgene (adHGF). The medium of group B consisted of transforming growth factor-β1(TGF-β1,10 ng/ml), basic fibroblast growth factor(bFGF,25 ng/ml) addexamethasone (DEX,10-7mol/L) with 15%FBS in DMEM. Cartilage slices wereobtained from femoral condyles and patellar grove in the same rabbit. The minced cartilage was digested in Ⅱ collagenase (3 mg/ml) to obtain chondrocytes(Group D). The change of cell appearance, proliferation capacity, glycosaminoglycans(GAG), immunohistochemical staining for type Ⅰ, Ⅱ collagen were observed during the 5th passage MSCs and MSCs after induction or gene modification. Expression of mRNA for type Ⅰ and Ⅱ collagen was detected by RT-PCR. Results Primary MSCs proliferated as shortspindle shape, while the 5th MSCs showed longspindle shape. Positive stain of type Ⅰ collagen could be found in groups A, B and C, while positivestain of type Ⅱ collagen was shown in groups B and D. The content of GAG in group B was higher than that in group A, but there was no significant difference between them（Pgt;0.05）, and there was significant difference between groups A and D（Plt;0.05）. No significant difference was noted in groups A,B and C on proliferation by MTT（Pgt;0.05）,except that of at the fourth day after transfection between groups A and C（Plt;0.05）. RT-PCR demonstrated that MSCs always had higher levelsof mRNA type Ⅰ collagen in groups A, B and C. The expression of mRNA type Ⅱ collagen was identified in groups B and D, and only low levels of mRNA type Ⅱ collagen in group C. Conclusion The above results indicate MSCs have a natural tendency of osteogenic differentiation in vitro culture, and also demonstrate the chondrogenic potency with the technique of cytokines induction or gene modification after passage. MSCs can be transfected efficiently being seed cells in tissue engineered bone or cartilage to accept target genes such as adHGF, and have a higher levels of expression in vitro, which lasted 4 weeks at least.
Rolling enrollment is a common method for participant recruitment in medical practice. In the longitudinal data, where researchers are often interested in outcomes occurring after a certain period of treatment, the definition of causal effects differs from that in the cross-sectional data. It poses new challenges for the application of matching methods in the longitudinal studies. Longitudinal matching is an extension of matching methods in longitudinal studies involving static interventions such as rolling enrollment. Currently, longitudinal matching methods are widely applied in the comparative effectiveness research. This article elucidates the fundamental principles, applicable conditions, code implementation, and application instances of four longitudinal matching methods through theoretical discussions and empirical illustrations. It provides methodological references for estimating causal effects in longitudinal data analysis.
Objective To verify the effect of palatoplasty with or without velopharyngeal muscular reconstruction on the velar movement through the lateral radiography. Methods From October 1988 to October 2000, 62 patients with cleft palate and velopharyngeal insufficiency were treated. Of them, 32 were repaired by velopharyngeal muscular reconstruction (group A) and 30 by modified von Langenbeck’s procedure (group B). The lateral radiographs and cephalometric analysis were taken. The velopharyngeal closure, velar extensibility, the angle changes of velar elevation, the distance changes of velar levator eminence based on anatomy (LEA) to velopharyngeal closure line (VCL), the varieties in LEA, the comparison of LEA and velar levator eminence based on phonation (LEP), the distance comparison between posterior nasal spine (PNS) to LEA and LEP through soft palate line (SPL) were measured. Results During the phonation, group A was significantly greater than group B in the velopharyngeal closure rate(Plt;0.01)， the velar extensibility(Plt;0.05) and the location comparison between LEA and LEP(Plt;0.01); group B was significantly greater than group A in velar elevation angle (Plt;0.05), the varieties in LEA(Plt;0.05). In velar rest position, the distance of LEA to VCL was greater inB group than in A group(Plt;0.01). There was significant difference in thedistance comparison between LEA and LEP(Plt;0.05), difference between LEA and LEP(Plt;0.01) and the distance PNS-SPL-LEA and PNSSPL-LEP(Plt;0.05) within group B; contrary to the results within group A(P＞0.05). Conclusion The velopharyngeal muscular reconstruction in palatoplasty can result in a near normalizationof anatomic measurement of velar levator muscles and improve the velar functionand velopharyngeal competence. Repositioning of velar muscles in a more anatomic correct, transverse position is more important to improve the velar length andaccordant velar movement with velopharyngeal muscles in functional palatoplasty. The velar angle change and velar elevation during phonation are not determinative factors for velopharyngeal competence.
Objective To compare the outcomes of two operative methods, the anterior decompression in subsection and the anterior decompression in one section, which were used to treat multilevel cervical spondylotic myelopathy (CSM). Methods Data of multilevel CSM undergoing the anterior decompression in subsection (33 cases, the subsection group) and the anterior decompression in one section (19 cases, the one section group) from July 1999 to January 2004 were retrospectively analyzed. The- incidence of perioperative complications and the rate of fusion were evaluated by the postoperative X-ray and MRI examinations, and improvement of the neurological function was evaluated by the JOA score.Results The incidence of perioperative complications was 36.8%in the one section group, mainly including immigration of the plate and grafts,which was settled by the revision surgery; while the incidence of perioperative compilcations was 12.1% in the subsection group, mainly including the immigration of the titanium mesh. There was a significant difference between the two groups (Plt;0.05). 84.2％ of the patients in the one section group and 81.8％ of the patients in the subsection group developed bony fusion by the end of the follow-up (9-31 mon, averaged 112 mon), and there was no significant differencebetween the two groups (Pgt;0.05). According to the JOA score, the ratio of the improvement in the neurological function was 70.4% in the subsection group and 64.4% in the one section group. There was no significant difference between the two groups (Pgt;0.05). Conclusion The anterior decompression in subsection is more rational for the surgical treatment on the multilevel CSM than the anterior decompression in one section. It can provide an equal decompressive effect but a more stable local mechanical environment right after the surgery and can maintain it well, which is critical for the bony fusion.
Objective To investigate the clinical effect of vascularized and non-vascularized full-length phrenic nerve transfer on treating brachial plexus injury. Methods From August 1999 to March 2000, full-length phrenic nerve transfer to musculocutaneous nerve was conducted with the technique of Video-AssistedThoracic-Surgery in 15 patients（M 13, F 2）that all suffered from avulsion. Threekinds of procedures were carried out. The first was retaining initial point of phrenic nerve and dissecting full-length distal nerve (group A). The second waskeeping cervical segment and isolating thoracic segment of phrenic nerve (group B). The last was vascularized phrenic nerve transfer (group C). All these phrenic nerves were sutured to musculocutaneous nerves. The results of electrophysiology and function of biceps brachii muscle were compared. Results The lengthof the dissecting full-length distal nerves in group A, group B and group C compared with that of conventional operation increased by 17.8±1.1 cm, 10.2±1.0 cm and 8.8±0.5 cm respectively. There was significant difference when group A was compared with group B and group C, when group B was compared with group C. All three procedures had no significant difference and led to the same function recovery of biceps brachii muscle to grade Ⅲ about 6 months later. Conclusion There is no difference in treating effect between vascularized and non-vascularized full-length phrenic nerve transfer, when the recipientbed has normal vascularity.
Objective To compare the effect of small intestinal submucosa(SIS)and polypropylene mesh(PPM) on repairing abdominal wall defects in rats, and toprobe into the feasibility of using SIS to repair the abdominal wall defects. Methods 100 SD rats(50 males and 50 females)were randomly divided into 2 groups(n=50). Their weight ranged from 200 to 250 g.Full thickness abdominal wall defects (2 cm×2 cm) were created by surgery and were repaired with SIS and PPM respectively. At different postoperative time (1st, 2nd, 4th, 8th and 12th week), animals were sacrificed to make histological observation. The tensile strengthand the development of adhesions were measured and observed. Results 95 animals survived and were healthy after surgery. No inflammatory response and obvious immunoreaction were observed in both groups. One week after operation, the tensile strengthof abdominal wall in SIS group (204.30±5.13 mmHg) was lower than that in PPMgroup(240.0±10.0 mmHg) at 1st week(P＜0.05),and there were no difference at 4th, 8th, 12th week. Adhesions were more marked in PPM group thanthat in SIS group(P＜0.05). Conclusion Both SIS and PPM are histologically compatible when used in rats and can maintain sufficient tensile strength. SIS is superior to PPM in regards to tissue compatibility and adhesion formation.
Objective To study the influence of the pedicle length on the perforator flaps in hemodynamics. Methods Four mature swine (2 males, 2 females; weight, 23.0±2.0 kg) were applied to the experiment.Two transverse abdominal skin flaps, based on the superior epigastric pedicle orits rectus abdominal muscle perforators, were designed; each swine was used as its own control. At 2 hours and 1, 2, 3 weeks postoperatively, the skin paddle perfusion and the blood stream velocity in the superior epigastric artery were measured by the Laser Doppler Flowmeter and the Color Doppler Ultrasound, respectively. Flap survival percentages were calculated by the grid method at 1 week postoperatively. The swine were euthanatized, and they underwent angiography at 3 weeks postoperatively. Results At 2 hours and 1 week after operation, edema of the perforator flaps with the superior epigastric pedicle was more severe than that of the skin flaps with the rectus abdominal muscle perforator, and the skin perfusion had a statistical difference between the two kindsof flaps (Plt;0.05). The skin paddle viability and the skin perfusion had nostatistical difference after the first week postoperatively (Pgt;0.05). At 2hours and 1 week after operation, the blood stream velocity in the superior epigastric artery in the perforator flap with the superior abdominal artery pediclewas reduced, and there was a statistical difference between the two kinds of flaps (Plt;0.05); however, the velocity was almost the same after the first week postoperatively. Conclusion The excessively long pedicle of the perforator skin flap may have an unfavorable influence on the flap perfusion,especially during the first week after operation, because of the vascular compromise during the dissection of the long pedicle. The blood vessel anastomosis atthis level of the blood vessels may have no relationship with the perforator flap in hemodynamics. This study can also indicate that the ligation of the branches in the recipient vessels cannot make the perforator flaps overperfused.
Objective To explore the effective method for treatmentof fracturesof scapular neck.Methods A retrospective analysis of 30 patients with fractures of scapular neck was done. The patients were treated by operation or by nonoperation from May 1994 to May 2003. According to the degree of displacement,30 cases included 9 mild displaced fractures(lt;10 mm) and 21 severe displaced fractures(gt;10 mm). According to the location of fractures, there were 24 cases of surgical neck fractures and 6 cases of anatomical neck fractures. Of all 30 patients, 12 were treated by nonoperation and 18 by operation. All fractured scapularnecks were exposed through posterior approach and fixed with interfragmentary compression screws, reconstruction plates and so on after satisfactory reduction.Associated clavical fractures were exposed through Langer’s approach and fixed with Kirschner wire-tension band fixation construct, reconstruction plates and so forth. When followed up, the clinical examination was done and the X-ray filmswere taken to measure glenopolar angle(GPA). Herscovici’s score was adopted.Results Twenty-eight patients were followed up from 14 days to 9 years. Among 11 patients treated by non-operation, Herscivici score showed that 4 cases achieved the excellent result, 2 cases good, 2 cases fair and 3 cases poor and the X-ray film results showed that there were 6 cases of GPA＞20° and 5 cases of GPA＜20°. Of 17 patients treatedby operation, Herscivici score showed that 11 cases achieved the excellent result, 5 cases good and 1 case fair and the X-ray film results showed that there 16 cases of GPA＞20° and 1 case of GPA＜20°.Conclusion Fractures of scapular surgical neck with mild displacement can be treated by nonoperation, while fractures of surgical neck with severe displacement or associated with ipsilateral clavical fractures, and fractures of anatomical neck should be treated by operation to reconstruct the stabilityof shoulder and minimize the complications.
To compare the effectiveness of microdiscectomy and macrodiscectomy on the single-level lumbar disc protrusion (LDP). Methods Between November 2002 and October 2005, 241 patients with LDP underwent 2 surgical procedures: microdiscectomy (group A, 93 cases) and macrodiscectomy (group B, 148 cases). All patients had singlelevel LDP. In group A, there were 51 males and 42 females with an average age of 32.3 yeares (range, 18-47 years); there were 23cases of protrusion, 52 cases of prolapse, and 18 cases of sequestration with an average disease duration of 8.5 months (range, 1-18 months), including 8 cases at L2,3 level, 11 cases at L3,4 level, 35 cases at L4,5 level, and 39 cases at L5, S1 level. In group B, there were 81 males and 67 females with an average age of 31.8 years (range, 16-50 years); there were 37 cases of protrusion, 85 cases of prolapse, and 26 cases of sequestration with an average disease duration of 9.3 months (range, 1-20 months), including 9 cases at L2,3 level, 15 cases at L3,4 level, 63 cases at L4,5 level, and 61 cases at L5, S1 level. There was no significant difference in age, sex, segment level, type, or disease duration between 2 groups (P gt; 0.05). Results Immediate back and sciatic pain rel ief was achieved in 225 (93.4%) patients after operation. The satisfactory rates were 91.4% in group A and 87.8% in group B at 1 week after operation, showing no significant difference (P gt; 0.05). The length of incision, amount of bleeding, amount of drainage, and hospital ization time in group A were significantly fewer than those in group B (P lt; 0.05); while the operative time in group A was longer than that in group B, but showing no significant difference (P gt; 0.05). Dural laceration occurred in 4 cases of groupA and 5 cases of group B, superficial infections of incision occurred in 5 cases of group B and intervertebral space nfections occurred in 4 cases of group B, and epidural hematoma occurred in 1 case of group A. The perioperative compl ication rate (5.4%, 5/93) in group A was significantly lower (P lt; 0.05) than that in group B (9.5%, 14/148). LDP recurred in 4 cases (4.3%) of group A and in 9 cases (6.1%) of group B postoperatively, showing no significant difference (P gt; 0.05); of them, 11 cases received second operation and 2 cases were treated conservatively. All cases were followed up 36-77 months (mean, 51.4 months). There were significant differences in visual analog scale (VAS) and Oswestry disabil ity index (ODI) between 2 groups at the last follow-up and preoperation (P gt; 0.05), but there was significant difference in VAS at 1 week postoperatively between 2 groups (P lt; 0.05). VAS and ODI were obviously improved at 1 week and last follow-up when compared with preoperation (P lt; 0.05). There was no significant difference in the improvement rates of VAS and ODI between 2 groups at last follow-up (P gt; 0.05). According to cl inical evaluation of Modified Macnab criteria, the excellent and good rate was 90.3% in group A and 86.5% in group B at final follow-up (P gt; 0.05). Conclusion Both macrodiscectomy and microdiscectomy are effective for LDP, furthermore microdiscectomy is less invasive than macrodiscectomy. Microdiscectomy is recommended to treat single-level LDP.
Objective To explore the effects of various kinds of internal fixations on unstable intertrochanteric femoral fractures. Methods From January 2000 to December 2004,88 cases of unstable intertrochanteric femoral fractures were treated. There were 52 males and 36 females (aged 19-86 years). Twenty-two cases were caused by fall from height, 36 by motor vehicle accident and 20 by fall and 10 by tumble. They were divided into 4 groups according to 4 kinds of internal fixations: dynamic hip screw(DHS,group A, n=42), anatomical proximal femur bone plate (group B, n=23), proximal femoral nail（PFN，group C, n=8）and dynamic condylar screw (DCS, group D, n=15). According to the modified Evan’s classification, fractures were all unstable type and were classified as follow types: group A (15 type Ⅲ, 8 type Ⅳ and 19 type Ⅴ); group B (12 type Ⅲ, 5 type Ⅳ and 6 type Ⅴ); group C (3 type Ⅲ,2 type Ⅳ and 3 type Ⅴ); and group D (10 type Ⅲ,3 type Ⅳ and 2 type Ⅴ). The data of operative time, intra-operative blood loss, intraoperative complications, fluoroscopy exposures, clinical healing time of fracture, post-operative restored function and postoperative complications were recorded and analyzed statistically using the SPSS 12.0 software package.Results All patients were followed up for 12-48 month (18 months on average). All patients achieved clinical healing. Coxa varus occurred in 3 cases of group A, in 1 case ofgroup C and in 3 cases of group D . The differences were of no statistical significance in operative time and postoperative complications between 4 groups (P＞0.05). The difference was of statistical significance in the blood loss between groups A,B and groups C,D (P＜0.05) but no statistical significance between group C and group D (P＞0.05). The difference was of statistical significance in the fluoroscopy exposures, clinical healing time of fracture and postoperative complications between group B and the other groups (P＜0.05). The difference was of statistical significance in the postoperative restored functions between group D and theother groups (P＜0.05). Conclusion The anatomical proximal femur bone plate is a useful device in the treatment of unstable intertrochanteric femoral fracture. The operative manipulation is simple and the hip functions recover well.