Clinical effectiveness of less invasive intramedullary nail fixation combined with titanium cable cerclage for subtrochanteric fractures / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the surgical technique and clinical effect of less invasive intrame-dullary nail fixation combined with titanium cable cerclage in the treatment of subtrochanteric fractures.@*METHODS@#A retrospective study was performed in 46 cases of subtrochanteric fractures in Peking University People's Hospital from January 2015 to December 2017. Among them, there were 14 males and 32 females, with an average age of (77.83±10.66) years (44-92 years); 17 cases on the left side and 29 cases on the right side. The causes of injury included crash from a height, traffic accident and accidental fall. According to Seinsheimer classification, there were 26 cases of type Ⅱ, 11 cases of type Ⅲ, 9 cases of type Ⅳ, and these cases were all closed injury. After admission, these patients underwent continuous tibial tuberosity bone traction to maintain the length and force line of the lower extremity, so as to reduce the difficulty of intraoperative fracture reduction. Anticoagulant therapy was given before operation to reduce perioperative thrombotic complications. All the patients were treated with less invasive intramedullary nail fixation combined with titanium cable cerclage. Operation time, blood loss during surgery, time of fracture healing were recorded, Harris and Sanders scoring system were used to assess hip function after operation at each follow-up time point.@*RESULTS@#All the included patients underwent surgery successfully. Average operative time and intraoperative blood loss of these patients were (131.09 ± 20.06) min and (191.96±111.03) mL, respectively. All the patients were followed up satisfactorily, with an average follow-up time of 28 months. The fractures received bone healing within 3-6 months, average hospital stay was (10.61±2.85) days. The Sanders score was excellent in 3 cases, good in 37 cases and common in 6 cases, with an excellent and good rate of 86.96%. The Harris score was excellent in 6 cases, good in 36 cases, with an excellent and good rate of 91.30%. There were no cases of wound infection, loss of reduction, nonunion of fracture or internal fixation failure. Hip pain symptoms were effectively relieved in most patients.@*CONCLUSION@#Less invasive intramedullary nail fixation combined with titanium cable cerclage can obtain good alignment and stability of fracture ends, which is an effective method for the treatment of subtrochanteric fractures.

A mid-term clinical follow-up study on repair of the meniscus tears by a modified arthroscopic outside-in puncture suture technique / 北京大学学报(医学版)

OBJECTIVE@#To investigate the clinical effect of a modified arthroscopic outside-in suture technique in the treatment of meniscus tear using a spinal needle.@*METHODS@#From January 2015 to October 2017, 95 patients treated with this method were followed-up. Among these cases, there were 36 males and 59 females. The age of the patients ranged from 16 to 77 years, (46.79±18.07) years in average. Among them, there were 28 patieats aged 16-35, 53 patients aged 36-65, and 14 patients aged over 65 years old. 28 cases were diagnosed with medial meniscus tear, 43 cases with lateral meniscus tear and 24 cases with both medial and lateral meniscus tear. Causes of the injury included sports, sprain, etc. According to Barrett standard, the clinical healing of meniscus tear was judged. Lysholm score, knee range of motion, visual simulation score (VAS) and magnetic resonance imaging (MRI) were used to evaluate the postoperative knee function and recovery of the patients.@*RESULTS@#The 95 patients were followed up for 22 to 36 months, with an average of (28.32±3.98) months. According to Barrett standard, 90 patients (94.7%) obtained meniscus clinical healing. Meniscal healing rates were 96.43%, 96.23% and 85.71% in the three age groups, respectively. The meniscal healing rate was lower in the elderly group, but there was no significant difference in statistical results (P=0.262). Five patients had deep tenderness in the joint space of the injured side, and the overstretch test was positive. The preoperative and postoperative VAS scores, Lysholm scores and knee motion were compared in each group, and the differences were statistically significant (P < 0.01). At the end of the last follow-up, there were no cases of knee joint effusion, swelling and interlocking, and the joint function was effectively improved in most patients. No surgical site infection, periarticular vascular/nerve injury or knotting reaction was found during the follow-up.@*CONCLUSION@#This modified arthroscopic outside-in suture technique using a spinal needle has the characteristics of simple operation, small trauma and rapid recovery, and the mid-term follow-up results were satisfactory. Therefore, we consider this method to be a safe and efficient method for the treatment of meniscus anterior horn and body tear.

Correlation analysis between rotator cuff tear and the superior migration of humeral head / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the association between rotator cuff tear and the proximal migration of humeral head.@*METHODS@#In this research, we retrospectively selected 30 patients with unilateral rotator cuff tear in Peking University People's Hospital from September 2015 to May 2016, who received magnetic resonance imaging (MRI) and X-ray of the painful shoulder before enrollment in this study, the duration between the two examinations was no longer than 1 week, and also there was no past history of surgery in the selected shoulders. There was no other exclusion criteria. Upward migration index (UMI) was the ratio between the distance of humeral head center to the lower surface of acromion, and the radius of humeral head circle, which could help to minimize the effect of anatomy difference and imaging magnification, compared with the traditional acromiohumeral distance (AHD). Then we introduced this index to stratify the selected 30 patients into 3 groups, and each group contained 10 patients, UMI of group 1 was >1 and ≤1.2, UMI of group 2 was >1.2 and ≤1.4, UMI of group 3 was >1.4. As the supraspinatus was most commonly affected by pathological change among the four rotator cuff tendons, we took it as the research object. Then we used the Spearman correlation analysis to evaluate the relationship between UMI and fatty degeneration, rotator cuff tear size and the thickness of ruptured supraspinatus tendon from X-ray and MRI.@*RESULTS@#In the A-P view, the average UMI was 1.33 (1.02-1.51, SD: ±0.22). UMI and the tear size had a significant negative correlation (R=-0.584, P<0.01), and also there was a negative correlation between the fatty degeneration of the supraspinatus (R=-0.312, P=0.033). However, there was no correlation between UMI and the thickness of ruptured supraspinatus (R=0.127, P=0.071).@*CONCLUSION@#UMI is related with the fatty degeneration of supraspinatus and the tear size. The reduction of UMI is a predictable and reliable mark of rotator cuff tear and degeneration in clinic. Physicians can use physical examination and X-ray first when facing the patients with shoulder pain, which is convenient and helpful for evaluating rotator cuff tears.

Minimally invasive treatment of the KobyGard system for plantar fasciitis: a retrospective study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Calcodynia is a persistent condition that podiatric surgeons frequently see among their patients, and plantar fasciitis is the main reason for pain. When systematic conservative treatments fail to alleviate these conditions, it requires surgical intervention, mainly plantar fascia release surgery, which used to be an open heel release surgery. This study aimed to investigate whether minimally invasive treatment of the KobyGard system is more safe and effective for plantar fasciitis.</p><p><b>METHODS</b>From May 2009 to May 2012, a total of nine patients, three males and six females with plantar fasciitis, were treated in the Peking University People's Hospital with minimally invasive instruments, the KobyGard system, for the release of plantar fascia. Three patients, experiencing bilateral calcaneodynia, underwent bilateral surgery. One patient had bilateral calcaneodynia with enthesiopathy of Achilles tendon, and underwent Achilles tendon surgery. Preoperative and postoperative Visual Analogue Scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot scores, Roles and Maudsley scores and SF-36 questionnaires were evaluated.</p><p><b>RESULTS</b>The nine patients were successfully followed up. The average postoperative follow-up time was 13.2 months and it varied from 2.0 months to 21.0 months. Pre- and postoperative average scores of VAS was 9.3 and 1.9 (P < 0.001), respectively. Pre- and postoperative average scores of AOFAS hind foot was 36.0 and 82.0 (P < 0.001), respectively. There was also a statistically significant amelioration in SF-36 scores and the Roles and Maudlesy scores. Eight patients were satisfied with the surgery outcome.</p><p><b>CONCLUSION</b>Minimally invasive surgery treatment of the KobyGard system for plantar fasciitis has the advantages of shorter operation time, ease of operation, and similar satisfaction rates with open surgery, but with smaller surgical incision.</p>

Positioning study of cervical vertebra pedicle axial line projective point by computed tomography image reconstruction / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Safe placement of the screws is a critical aspect of trans-pedicle internal fixation, and little information on in vivo morphology of the cervical vertebrae pedicle measured with imaging methods is available. The aim of this study was to measure the dimensions of cervical vertebrae C3 to C7 and provide screw length, screw diameter and tilt angle for clinical cervical vertebra trans-pedicle internal fixation.</p><p><b>METHODS</b>Thirty Chinese men and women underwent high-speed spiral computed tomography measurements to obtain data for C3 to C7, and the morphology of the cervical vertebra pedicles was reconstructed.</p><p><b>RESULTS</b>Reconstructed computer tomography image data revealed that: (1) pedicle sponge width increased incrementally from C3 to C7, (2) pedicle depth was similar for C3 to C7, (3) pedicle angle decreased incrementally from 47.20° to 33.76° for C3 to C7, and (4) pedicle point to midline distance was similar for C3 to C7. There were no statistical differences in morphological data between the right and the left side. Men had statistically larger values than women for all morphological parameters.</p><p><b>CONCLUSIONS</b>Reconstructed computed tomography images can provide useful data for clinical cervical vertebra trans-pedicle internal fixation. The individual measurement of cervical vertebra pedicles is recommended for safe placement of trans-vertebra pedicle screws.</p>

Clinical effect of distal radius fracture treated with open reduction and internal plate fixation / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>For some specific comminuted unstable intra-articular fracture, the plaster cast can not maintain the alignment of the articular surface effectively. The aim of this study was to evaluate the clinical effects of distal radius fracture treated with open reduction and internal plate fixation retrospectively.</p><p><b>METHODS</b>From January 2002 to March 2010, 539 cases of distal radius fracture were treated with open reduction and internal fixation, including 184 males and 355 females aging 21 - 72 years (mean 57 years). Fractures were caused by falling to the ground in 459 cases, by traffic accident in 62 cases and by athletic injuries in 18 cases. Of 539 cases, there were 523 cases of closed fracture and 16 cases of open fracture. According to Arbeitsgemeinschaft fur Osteosynthesefragen (AO) standards of classification, there were 14 cases of A2 type, 22 of A3 type, 18 of B1 type, 24 of B2 type, 62 of B3 type, 91 of C1 type, 162 of C2 type and 146 of C3 type. The time from injury to operation was 1 - 16 days (mean 5 days). All patitents received open reduction and internal plate screw fixation. Forty-seven patients with bone defect were given 6 - 15 g autologous ilium and 75 cases were given 5 ml calcium sulphate artificial aggregate after reduction.</p><p><b>RESULTS</b>All incisions healed by first intention after operation. Patients were followed up for 15 to 32 months postoperatively (mean 22 months). The fractures healed within 10 - 18 weeks after operation (mean 12 weeks). During the last follow-up, the mean palmar tilt was (7.0 ± 0.9)° and the mean ulnar variance was (21.0 ± 4.2)°, showing significant difference when compared with preoperation ((-5.0 ± 1.2)° and (8.0 ± 3.8)°). The radial heights were not abbreviated. According to Gartland and Werley assessment system, the results were excellent in 314 cases, good in 163 cases, fair in 46 cases, and poor in 16 cases 12 weeks after operation, the excellent and good rate was 88.5%.</p><p><b>CONCLUSIONS</b>The clinical effect of distal radius fracture treated with open reduction and internal plate fixation was relatively satisfactory. Meticulous operation procedure and individual rehabilitation strategy contribute to the wrist joint functional recovery.</p>

Three kind of scoring system for proximal humeral fractures in patients with postoperative functional review of evaluation: a multicenter study / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the ASES, Constant and HSS score systems and their significance on postoperative function of the shoulder.</p><p><b>METHODS</b>Totally 172 cases of proximal humeral fracture of five affiliated hospital from September 2004 to September 2008 were analyzed. All the functional outcome of the involved shoulder were evaluated by ASES, Constant, HSS score and patient self score. The correlations and agreement of three shoulder scales were analyzed with Pearson correlation test and Bland-Altman plot in different age groups and fracture types.</p><p><b>RESULTS</b>(1) The Constant score were lower than other two scores in the same age group and fracture type (F = 13.62 and 4.80, P < 0.05). (2) The correlations between three shoulder scales: ASES and Constant (r = 0.754, P = 0.0003), ASES and HSS (r = 0.755, P = 0.0001), Constant and HSS (r = 0.858, P = 0.0002). The correlations between three shoulder scales and patient self evaluation: ASES (r = 0.602, P = 0.0002), Constant (r = 0.705, P = 0.0001), HSS (r = 0.663, P = 0.0037). The Bland-Altman plot shows three shoulder scales have good agreement. (3)The correlation between Constant score and patient self evaluation decreased in the elder group and severe fracture type.</p><p><b>CONCLUSIONS</b>ASES, Constant, HSS shoulder score systems are all fit to evaluate the functional outcome of the shoulder, they have good correlation and agreement. Constant score in recommended for its high correlation coefficient with patient self evaluation score. However, its age bias must be paid attention in clinical practice. ASES shoulder score can be used in remote follow-up.</p>

Multicenter follow-up study of ankle fracture surgery / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Few data on ankle fractures in China from large multicenter epidemiological and clinical studies are available. The aim of this research was to evaluate the epidemiological features and surgical outcomes of ankle fractures by reviewing 235 patients who underwent ankle fracture surgery at five hospitals in China.</p><p><b>METHODS</b>This study included patients who underwent ankle fracture surgery at five Chinese hospitals from January 2000 to July 2009. Age, gender, mechanism of injury, Arbeitsgemeinschaft für Osteosynthesefragen (AO) fracture type, fracture pattern, length of hospital stay and treatment outcome were recorded. Statistical analyses were conducted using SPSS software. The American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale, visual analogue scale (VAS), and arthritis scale were used to evaluate outcome.</p><p><b>RESULTS</b>Of 235 patients with ankle fractures, 105 were male with an average age of 37.8 years and 130 were female with an average age of 47.3 years. The average follow-up period was 55.7 months. There were significant differences in the ratios of patients in different age groups between males and females, and in mechanisms of injury among different age groups. There were also significant differences in the length of hospital stay among different fracture types and mechanisms of injury. In healed fractures, the average AOFAS ankle-hindfoot score was 95.5, with an excellence rate of 99.6%, the average VAS score was 0.17, and the average arthritis score was 0.18. Movement of the injured ankle was significantly different to that of the uninjured ankle. There were no significant differences between AO fracture types, fracture patterns or follow-up periods and AOFAS score, but there were some significant differences between these parameters and ankle joint movements, pain VAS score and arthritis score.</p><p><b>CONCLUSIONS</b>Ankle fractures occur most commonly in middle-aged and young males aged 20 - 39 years and in elderly females aged 50 - 69 years. The most common mechanisms of injury are twisting injuries and falls from a standing height or less. The results of surgical treatment are satisfactory.</p>

Clinical features analysis of femoral neck fractures in 219 patients / 中华外科杂志

<p><b>OBJECTIVES</b>To investigate the clinical features of femoral neck fractures and analyze related causes.</p><p><b>METHODS</b>The clinical data of patients with femoral neck fractures from June 2002 to August 2009 were retrospectively analyzed. The gender, age, fracture side, fracture type, basic social data, activities before injury, injury causes and treatment were analyzed.</p><p><b>RESULTS</b>A total of 219 patients (106 male and 113 female) was analyzed. All patients were divided into children group (age < 16 years), adult group (age ranged from 16 to 60 years) and older group (> 60 years). There were 5 patients (2.3%) in the children group, 81 patients (37.0%) in the adult group and 133 patients (60.7%) in the older group. There were 11 patients (5.0%) with Garden I fractures, 32 patients (14.6%) with Garden II fractures, 90 patients (41.1%) with Garden III fractures and 86 patients (39.3%) with Garden IV fractures. Fall damage and traffic injury were the main injury types. Home and public place were the main injury sites.</p><p><b>CONCLUSIONS</b>The incidence of femoral neck fracture shows the highest in the old persons. The male patients with femoral neck fractures are more than female patients in children and adult group, while the male patients with femoral neck fractures are less than female patients in older group. The dominant fractures type according to Garden classification is Garden III fractures in children and adult groups, but Garden IV fractures in older group. Fall damage and traffic injury are the main injury types. Home and public place are the main injury sites.</p>

Treatment of osteoporotic compression fracture of thoracic/lumbar vertebrae by kyphoplasty with SKY bone expander system / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate prospectively the effectiveness of kyphoplasty with SKY bone expander system in treatment of compression fracture of thoracic/lumbar vertebrae and correction of the deformity.</p><p><b>METHODS</b>Twenty-five patients with thoracic/ lumbar vertebral osteoporotic compression fracture were admitted to our hospital between March 2007 and March 2008, and treated by kyphoplasty with SKY bone expander system. Patient's pain status was rated with Visual Analogue Scale (VAS) score system 1 day before and 1 hour, 48 hours, 6 months, 12 months after surgery. In addition, Rolland-Morris and Oswestry disability questionnaires (RDQ and ODI) were used for survey 1 day before and 1, 6, 12 months after surgery. Pre- and post-operative vertebral heights and Cobb's angles were measured based on the X-ray films and statistically analyzed.</p><p><b>RESULTS</b>There were 27 fractured vertebrae in these 25 patients. After SKY kyphoplasty, the Cobb's angles (9.8 degree ± 9.76 degree) were significantly reduced compared with preoperative angles (17.18 degree ± 9.35 degree P < 0.05), and the average improvement rate was 39%. Patients'pain VAS scores were also greatly improved after operation (P < 0.05). Moreover, postoperative RDQ and ODI scores were significantly smaller than preoperative values (P < 0.05).</p><p><b>CONCLUSIONS</b>Kyphoplasty with SKY bone expander system provides an effective method for treating thoracic/ lumbar vertebral osteoporotic compression fracture, with the advantages of small surgical wound and short duration. It can effectively recover the anterior and medial heights of fractured vertebrae (33% and 50%, respectively), reduce the Cobb's angle, quickly alleviate pain and improve patients'quality of life in a relatively short time period.</p>

Clinical outcomes of total elbow replacement in the treatment of complex distal humeral fractures / 中华外科杂志

<p><b>OBJECTIVE</b>To discuss the efficacy of total elbow replacement in the treatment of complex distal humeral fractures.</p><p><b>METHODS</b>From May 2005 to October 2008 12 patients were retrospectively studied who were diagnosed complex fractures of the distal humerus and treated by total elbow replacement (Coonrad-Marrey). The mean age was 60 years old, the mean follow-up time was 12 months. According to AO classification, there was 3 C2 and 9 C3. The study included: pain evaluation, range of motion, elbow stability, muscle strength, complications, Mayo elbow score, DASH score, radiological assessment of ectopic bone formation and loosening.</p><p><b>RESULTS</b>Two cases with mild pain. The mean flexion is 98.3 degrees, extension limit is 17.9 degrees, mean pronation is 82.9 degrees and supination is 70.8 degrees. All joints were stable postoperatively. All patients were satisfied with the outcome. There was 1 case of superficial soft tissue nonhealing and 2 cases of ulnar nerve symptoms. No ectopic bone formation or loosening was found. Mayo elbow score was 3 cases of excellent and 9 cases of good. The mean DASH score was 41.3.</p><p><b>CONCLUSION</b>Total elbow replacement can be used in such conditions as severe osteoporosis, severe comminution that internal plates can not get stable fixation, severe cartilage damage (because of fracture or inflammatory arthritis) that indicate traumatic or inflammatory arthritis.</p>

Study on the overall anatomical features and clinical value of lumbar nerve root, plexus and branches in CT reconstruction / 中华外科杂志

<p><b>OBJECTIVE</b>To identify the overall anatomical characteristics and the clinical value of the lumbar nerves under CT multiplanar reconstruction.</p><p><b>METHODS</b>Fifty normal subjects and 30 patients with LN diseases (51 sides) were selected, including 10 patients with lumber intervertebral disk hernia, eight patients with spinal stenosis, 5 patients with spondylolisthesis, 1 patient with tethered cord syndrome, 1 patient with lumbar scoliosis, and 5 patients with spinal trauma The 16-slice helical CT (Light Speed, GE Company) was used for scanning the lumbar vertebra with multiplanar reconstruction in Workstation (ADW4.1) with UNIX System in DICOM format. The image was set on the same slice for the overall anatomy and manifestations of the lesions.</p><p><b>RESULTS</b>The same-slice imaging showed the strip-like LN slightly lower than the surrounding muscle in density. Each LN went out of the dural sac at an acute angle. The course of the lumbar plexus and its major branches, including the obturator nerve, femoral nerve and reproductive nerve, and their relations to the adjacent structures were clearly revealed. The percentage of the segments displayed was well associated with the reconstruction angle, with the order being oblique coronal > outward-rotated oblique coronal > oblique sagittal > coronal > sagittal section. The major manifestations of abnormal LN included compression and displacement (50 sides, 98.0%), morphological changes (49 sides, 96.1%), adhesion (41 sides, 80.4%).</p><p><b>CONCLUSIONS</b>The CT multiplanar reconstruction is ideal for the imaging of the overall size, shape, running and tension of the LN root; it is valuable in clinical diagnosis.</p>

Comparative study of distal radial fractures in the elderly treated with locking and non-locking plates / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the clinical difference of locking and non-locking plates in the treatment of distal radial fractures in the elderly.</p><p><b>METHODS</b>Forty-nine patients with an average age of 68 years were included. The mean follow-up was 30 months. Five cases were traffic related injury, and others were simple falls. Fractures were classified according to AO classification system: 9 cases of A3, 4 cases of B, 11 cases of C1, 18 cases of C2, 7 cases of C3. Patients were grouped as locking group (29 cases) and non-locking group (20 cases).</p><p><b>RESULTS</b>Significant difference was not found between the two groups in active range of motion, Gartland and Werley score, radiological measurements and score.</p><p><b>CONCLUSION</b>Locking and non-locking plates have the same clinical outcome in the treatment of distal radial fractures in the elderly.</p>

Positioning study of cervical vertebra pedicle axial line projective point by CT image reconstruction / 中华外科杂志

<p><b>OBJECTIVE</b>To improve the safety and accuracy of trans-pedicle internal fixation for cervical vertebra by the parameter data measuring by CT reconstruction.</p><p><b>METHODS</b>Thirty volunteers were enrolled and be subjected to high-speed spiral CT for getting the data of C3-C7. The data included pedicle point-midline distance, pedicle sponge width, pedicle angle. The cervical vertebra pedicle morphology were reconstructed.</p><p><b>RESULTS</b>Reconstructed CT image data displayed that pedicle sponge width become larger and larger from C3 to C7; the pedicle depth didn't change significantly even from C3 to C7; pedicle angle become small from C3 to C7 and the range is from 33.76 degrees to 47.20 degrees; pedicle point-midline distance were almost similar even from C3 to C7. There were not statistical differences between the right side and the left side, but there were statistical differences between man and woman.</p><p><b>CONCLUSION</b>Reconstructed CT image can provide useful data for clinical cervical vertebra trans-pedicle internal fixation.</p>

An experimental study on biomechanical effects due to unilateral cortical bone defect in long tubular bone / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the biomechanics effect due to unilateral cortical bone defect of different size in long tubular bone.</p><p><b>METHODS</b>Seventy-six pieces of Sanhuang cock tibial were randomly divided into 7 groups. The unilateral diaphyses cortical were drilled holes of different size, include 1.5, 2.0, 2.5, 3.0, 3.5, and 4.5 mm, performed three-points bend single experiment. The intact bone cortical group was control group.</p><p><b>RESULTS</b>When there were bone structure destructions, the maximum of the bend load between 3 groups which bone defect diameter were 1.5 mm, 2.0 mm, and control was not significant difference (P = 0.824, 0.865), but the maximum of the bend load between 3 groups which bone defect diameter were 2.5, 3.0, and 3.5 mm decreasing about 14 percent of the control group (P = 0.015, 0.010, 0.021). and the maximum of the bend load which bone defect diameter were 4.5 mm decrease about 23 percent of the control group (P = 0.001).</p><p><b>CONCLUSIONS</b>If the diameter of bone cortical defect is within 22.63 +/- 1.39 percent of bone cortical outer diameter, there was no reduction of the bend load. If the diameter of bone cortical defect is beyond 29.36 +/- 2.07 percent of bone cortical outer diameter, it decreases the maximum bend load of the long tubular bone, but the reduced range is not complete with direct ratio to the bone defect size.</p>

Study on the adoption of Schwann cell phenotype by bone marrow stromal cells in vitro and in vivo / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To explore the possibilities of bone marrow stromal cells (MSCs) to adopt Schwann cell phenotype in vitro and in vivo in SD rats.</p><p><b>METHODS</b>MSCs were obtained from tibia and femur bone marrow and cultured in culture flasks. Beta-mercaptoethanol followed by retinoic acid, forskolin, basic-FGF, PDGF and heregulin were added to induce differentiation of MSCs'. Schwann cell markers, p75, S-100 and GFAP were used to discriminate induced properties of MSCs' by immunofluorescent staining. PKH-67-labelled MSCs were transplanted into the mechanically injured rat sciatic nerve, and laser confocal microscopy was performed to localize the PKH67 labelled MSCs in the injured sciatic nerve two weeks after the operation. Fluorescence PKH67 attenuation rule was evaluated by flow cytometry in vitro.</p><p><b>RESULTS</b>MSCs changed morphologically into cells resembling primary cultured Schwann cells after their induction in vitro. In vivo, a large number of MSCs were cumulated within the layer of epineurium around the injured nerve and expressed Schwann cell markers, p75, S-100, and GFAP.</p><p><b>CONCLUSION</b>MSCs are able to support nerve fiber regeneration and re-myelination by taking on Schwann cell function, and can be potentially used as possible substitutable cells for artificial nerve conduits to promote nerve regeneration.</p>

Biomechanical study of flexor tendon repair in an in vivo curvature model / 中华外科杂志

<p><b>OBJECTIVE</b>To compare the biomechanical characteristics of 2 different repair methods:Modified Kessler and Tsuge.</p><p><b>METHODS</b>Eighty-four profound flexor tendons of 3(rd) toe of Sanhuang chicken were severed and repaired by either Modified Kessler or Tsuge method randomly. Six repaired tendons for each repair method were harvested at 0, 1, 4, 7, 10, 14, 21 days after operation and tested in an Instron 1185 biomechanical testing machine. An elongation force-elongation distance curve was obtained, and biomechanical meters (including rupture force and rupture work) were calculated from this curve.</p><p><b>RESULTS</b>Rupture force: rupture force significantly decreased at 10(th) and 14(th) day in both repair groups, and returned to immediate level at 21(st) day in Modified Kessler group but not in Tsuge group; Tsuge method was significantly higher than Modified Kessler group at time-points immediately and 7 days after operation. Rupture work: this work significantly decreased at 10(th) (65.17 mJ) and 14(th) (40.0 mJ) day and resumed to immediate level at 21(st) day in Modified Kessler group; While in Tsuge group, it decreased significantly at 14(th) and 21(st) day. Tsuge method was significantly higher than Modified Kessler group only at time 0.</p><p><b>CONCLUSION</b>The biomechanical properties decrease significantly after 10(th) day at both repair method groups. It resumes to immediate level at 21(st) day in Modified Kessler group. There is no significant difference after 10(th) day between both repair methods.</p>

Characteristics of work of adhesion release in the early period of flexor tendon healing / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the characteristics of work needed to release adhesion in the early stage of flexor tendon healing.</p><p><b>METHODS</b>Eighty-four profoundus flexor tendons of the 3rd toe of Sanhuang chicken were severed and repaired by either Modified Kessler technique or Tsuge technique randomly. At 0, 1, 4, 7, 10, 14, 21 d after the operation, 6 tendons from each repair technique group were harvested and tested by biomechanical test machine. An elongation force-elongation distance curve was obtained and work of adhesion release was calculated in this curve. Whether adhesion band had been released or not was confirmed by gross inspection immediately after the test.</p><p><b>RESULTS</b>Work of adhesion release: this work significantly increased at the 7th day in Modified Kessler group and at the 10th day in Tsuge group. Modified Kessler group was significantly higher than Tsuge group at the 7th day. At the 21st day after operation, adhesion could not be effectively released by full range excursion of flexor tendon profoundus.</p><p><b>CONCLUSION</b>Work of adhesion release begins to increase significantly since the 7th approximately 10th day postoperatively. At the 21st day after the operation, adhesion could not be fully released by full range of flexor tendon profoundus flexion.</p>

Changes and the clinical significance of muscle strength after different proportion tibial neurotomy / 中华外科杂志

<p><b>OBJECTIVE</b>To study the changes of the muscle strength after the selective tibial neurotomy and the relationship between the changes and the quantities of neurotomy, and to discuss the clinical significances.</p><p><b>METHODS</b>Twenty-four normal SD rats were divided into 4 groups with 6 in each. In group A, the left tibia nerve were cut off by 80%. 60% in group B, 40% in group C, 20% in group D, with the right as the control side. After 6 weeks measure the strength of the crural triceps and the weight of them.</p><p><b>RESULTS</b>In all the groups muscle weight and muscle strength decreased. 88.2% strength decreased on the average in group A, 54.2% in group B, 19.5% in group C, 4.7% in group D.</p><p><b>CONCLUSION</b>It will not damage strength of the crural triceps to cut off below 40% tibial nerve in SD rats.</p>

Chitin biological tube bridging the peripheral nerve with a small gap / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the possibility of bridging small peripheral nerve gap using a de-acetyl chitosan conduit.</p><p><b>METHODS</b>The sciatic nerves of right sides were cut at SD rats. They were divided into 5 Groups randomly; Group A: epineurium suture in situ (n = 24); Group B: biological conduit with a small gap for bridging the peripheral nerve (n = 24, with 5 mm gap); Group C: epineurium suture with distal stump rotated 180 degrees (n = 24); Group D: bridging the nerve by biological conduits with a small gap, but the distal stump rotated 180 degrees (n = 24, with 5 mm gap); Group E: biological conduit with a small gap for bridging the peripheral nerve with NGF (n = 24). Electrophysiological examination, histological examination and myelinated axon counting were applied after 2, 4, 6, 8 weeks after operation respectively.</p><p><b>RESULTS</b>Regenerated nerve fibers were seen in the distal nerve segments of all 5 groups; The nerve conduction velocity of small gap group (group B, D) was faster than that of corresponding simple epineurium suture group (group A, C) at all 2, 4, 6, 8 week time point (P < 0.05). The myelinated axon counting of small gap group (group B, D) was faster than that of corresponding simple epineurium suture group (group A, C) at all 4, 6, 8 week time point (P < 0.01), and there was no statistically significant difference at 2 week time point.</p><p><b>CONCLUSION</b>The repair effects of chitin conduit bridging peripheral nerve with small gap (5 mm) are better than that of epineurium suture directly, and possess the potential to substitute the epineurium suture.</p>