Volume 123  ·  Issue 21  ·  2010

With the development of medical science,orthopaedic traumatology, which derives from orthopaedics, becomes an important sub-discipline.Orthopedic traumatology includes: (1) fracture of limbs and spine; (2) injury to blood vessels, nerves, muscles and tendons; (3) traumatic skin defects of the limbs; (4)the limb injury and spinal cord injury, etc. Since the end of the 20th century, the orthopaedic tranmatology field has been developing rapidly, and is becoming one of the four major sub-groups of orthopaedics along with musculoskeletal and tumor surgery, spinal surgery, and joint surgery. 1-4

The principle of navigation surgery was first adopted in neurosurgery where a mechanical rigid frame was used in the stereotactic surgery to locate a deep ganglia and tract in the brain by Clark and Horsley1 in 1906. The planning was based on anatomical atlas of the brain and was not patient specific. The navigation procedure was possible with a rigid mechanical frame to define the trajectory with a rigid instrument holder on a rigid fixation of the operating structure, i.e. the skull. With the advancements in 3-D medical imaging, i.e. CT in 1971,MR imaging in 1973, general stereotaxis was possible and became specific to anatomy of each individual patient.Together with the advancement of computer technology:VAX in 1976, Apple in 1977, IBM personal computer in 1981, computer assisted stereotaxis was possible and in 1985, the term computer assisted surgery (CAS) was proposed by Sohn and Robins.2 With further development of 3-D tracking by NDI with Optotrak 1990, computer assisted orthopaedic surgery (CAOS) developed and gradually became widely applicable in clinical practice。

Abstract：Background Theoretic advantages of cervical disc arthroplasty include preservation of normal motion and biomechanics in the cervical spine, and reduction of adjacent-segment degeneration. The clinical and radiographic effects of cervical disc arthroplasty in short term have been ascertained. The aim of this study is to research the data of mid-term results.Methods In this prospective cohort study, 50 patients who underwent cervical disc arthroplasty from December 2003 to January 2006 were enrolled. There were 39 patients who received 1-level disc arthroplasty, and 11 patients received 2-level disc arthroplasty, with an average age of 50.9 years (range from 29 to 73). The median follow-up was 41.85months (range from 36.00-55.63 months). Patients were followed prospectively with respect to their symptoms,neurologic signs, and radiographic results.Results The median value of Japanese Orthopaedic Association (JOA) score was 14.0 before surgery, and 16.5 at the most recent follow-up (P ＜0.01). The median value of the recovery rate of the JOA score was 92.2%. The preoperative range of motion (ROM) at the indexed level was (10.40±4.97)°, which has significantly correlated with the most recent follow-up ROM which was (8.56±4.76)° (P ＜0.05, r=0.33). The ROM at the operative level at the most recent follow-upwas greater than the value at the 3-month follow-up of (7.52±3.37)° (P ＜0.05). The preoperative functional spinal unit (FSU) angulation was (-0.96±6.52)°, which was not significantly correlated with that of the most recent follow-up value of (-2.65±7.95)° (P ＜0.01, r=0.53). The preoperative endplate angulation was (2.61±4.85)°, which had no significant correlation with that of the most recent follow-up value of (0.71±6.41)° (p ＞0.05).Conclusions The clinical and radiographic results of cervical disc arthroplasty are good in mid-term follow-up. The normal range of motion of the operated level and the biomechanics in the cervical spine are well preserved。

Abstract：Background The Dynamic Interspinous Assisted Motion (DIAM) system was designed to stabilize degenerative spinal segments without fusion surgery, maintain segment motion and prevent adjacent segment degeneration. The aim of thisstudy was to investigate clinical efficacy of the DIAM system in treatment of degenerative lumbar disease in China.Methods Eight cases of lumbar vertebral instability were treated with the DIAM system at Peking Union MedicalCollege Hospital from June 2006 to January 2008. There were 6 female and 2 male subjects with a mean age of 46.9years and a range of 40-52 years. Radiographs and scores on outcome measures included the visual analogue scale (VAS) for pain and the Oswestry disability index (ODI). These scores were recorded before surgery and after surgery at intervals of 3-month, 6-month, 1-year and the final follow-up visit.Results The follow-up time ranged from 12-31 months, with an average of 20.6 months. There were significant differences between preoperative and postoperative scores at each follow-up evaluation (P ＜0.05). However, there was no significant difference between each postoperative follow-up score (P ＞0.05). There were significant differences between preoperative and postoperative L4-5 segment activity at each time interval (P ＜0.05), but no obvious difference was found within each postoperative follow-up evaluation (P ＞0.05). The ODI and VAS score improvements were directly correlated with segment activity (r ＞0.7, P ＜0.05).Conclusions The DIAM system appears to be a useful and effective treatment in the surgical management of degenerative lumbar disease in certain patients. However, long-term follow-up is needed to evaluate the clinical outcomes of the device。

Abstract：Background There has been an increasing recognition of the importance of sagittal spinopelvic alignment in patients with scoliosis as it relates to clinical outcomes. However, the changes seen in sagittal spinopelvic alignment in adult idiopathic scoliosis patients is poorly defined. This study was conducted to evaluate the sagittal alignment of pelvis and spine in adult idiopathic scoliosis patients.Methods The sagittal parameters of the spine and pelvis were analyzed in lateral standing radiographs of 124 patients (mean age 47.4 years) with adult idiopathic scoliosis, including thoracic kyphosis (TK), thoracolumbar junction kyphosis (TLJ), lumbar lordosis (LL), pelvic incidence (PI), sacrum slope (SS), pelvic tilt (PT) and C7 plumb line (C7PL). The patients were divided into three groups according to the age: 20-40 years, 41-64 years, and ≥65 years. The parameters were compared with those in normal adults and adolescent idiopathic scoliosis (AIS) patients. The relationship between all parameters as well as age and sagittal parameters were analyzed.Results The PI in patients with adult idiopathic scoliosis was 58.1°±13.0°, which was significantly higher than that in normal adults. The PT (19.9°±10.6°) was also higher than that in both normal adults and AIS patients, while the SS (38.1°±12.0°) was similar or smaller. As age increased, C7PL, PT and TJL increased while LL decreased. There was no relationship between age and both PI and TK. PT had the strongest statistical association with the C7PL.Conclusions PI is higher in adult idiopathic scoliosis than normal subjects. The PT is the most relevant pelvic parameter to the global sagittal alignment of the spine. Age significantly influences sagittal parameters of the spine and pelvis except the PI and TK。

Abstract：Background Increasing the successful puncture rate of the percutaneous vertebroplasty (PVP) in thoracic vertebral compression fracture by unilateral puncture is a problem that spinal surgeons are trying to solve. The aim of this study was to assess the value of preoperative MRI imaging measurements for PVP using a unilateral puncture.Methods We performed a retrospective, comparative study of two groups of osteoporotic thoracic vertebral compression fracture patients who had received a PVP using a unilateral puncture. Group A (22 patients with 27 valid vertebrae) received PVP with a unilateral puncture between October 2005 and February 2007. Group B (18 patients with 24 valid vertebrae) received a routine MRI imaging measurements before a PVP between March 2007 and June 2008.We determined the target area to puncture based on the preoperative MRI cross-sectional images of vertebra. The PVP used a simultaneous puncture through a unilateral posterolateral approach, so the vertical distance from the point of skin puncture to the posterior median line, as well as the puncture angle, were measured using the MRI. The results were used to guide the PVP operation. We compared these two groups based on the average time for a single vertebra operation, the achievement ratio of puncture, and the incidence of bone cement leakage during surgery. The mean follow-up period was 14.2 months (range 12-23 months). The pre- and post-operative visual analogue score (VAS) (3and 12 months post-surgery), the variation of Oswestry disability index (ODI) and the incidence of long-term complications were also compared.Results The average time of a single vertebra operation in groups A and B were (34.7±5.4) and (23.3±4.2) minutes,respectively. In groups A and B, the success rates of puncture were 74.1% and 91.7%, respectively. Postoperative reduction of the average VAS scores in groups A and B at 3 and 12 months post-surgery were 5.8±2.1, 6.1±1.8, 6.1 ±2.0,6.2±1.6, respectively. However, the ODI increase was 41.6%±5.7%, 40.6%±6.0%, 46.3%±5.2%, 46.1%±6.7%. Paired t test evaluation of the values above showed a significant difference in the time of single-vertebra operation and the success rates between groups A and B (P ＜0.05), but no significant difference was seen in the reduction of VAS scores and ODI (P ＞0.05). There was no statistically significant difference in the complication rate between the two groups.Conclusions A preoperative MRI measurement effectively reduced the time of PVP with a unilateral puncture, which improved the success rate of the puncture without an additional risk of operation related complication。

Abstract：Background Spine surgery using computer-assisted navigation (CAN) has been proven to result in low screw misplacement rates, low incidence of radiation exposure and excellent operative field viewing versus the conventional intraoperative image intensifier (CⅢ). However, as we know, few previous studies have described the learning curve of CAN in spine surgery.Methods We performed two consecutive case cohort studies on pedicel screw accuracy and operative time of two spine surgeons with different experience backgrounds, A and B, in one institution during the same period. Lumbar pedicel screw cortical perforation rate and operative time of the same kind of operation using CAN were analyzed and compared using CⅢ for the two surgeons at initial, 6 months and 12 months of CAN usage.Results CAN spine surgery had an overall lower cortical perforation rate and less mean operative time compared with CⅢ for both surgeon A and B cohorts when total cases of four years were included. It missed being statistically significant,with 3.3% versus 4.7% (P=0.191) and 125.7 versus 132.3 minutes (P=0.428) for surgeon A and 3.6% versus 6.4%(P=0.058), and 183.2 versus 213.2 minutes (P=0.070) for surgeon B. in an attempt to demonstrate the learning curve,the cases after 6 months of the CAN system in each surgeon's cohort were compared. The perforation rate decreased by 2.4% (P=0.039) and 4.3% (P=0.003) and the operative time was reduced by 31.8 minutes (P=0.002) and 14.4 minutes (P=0.026) for the CAN groups of surgeons A and B, respectively. When only the cases performed after 12 months using the CAN system were considered, the perforation rate decreased by 3.9% (P=0.006) and 5.6% (P ＜0.001) and the operative time was reduced by 20.9 minutes (P ＜0.001) and 40.3 minutes (P ＜0.001) for the CAN groups of surgeon A and B, respectively.Conclusions In the long run, CAN spine surgery decreased the lumbar screw cortical perforation rate and operative time. The learning curve showed a sharp drop after 6 months of using CAN that plateaued after 12 months; which was demonstrated by both perforation rate and operative time data. Careful analysis of the data showed CAN is especially useful for less experienced surgeon to reduce perforation rate and intraoperative time, although further comparative studies are anticipated。

Abstract：Background The complicated anatomy of the cervical spine and the variation among pedicles reduces the accuracy and increases the risk of neurovascular complications associated with screw implantation in this region. In this study, we compared the accuracy of cervical (C2-C7) pedicle screw fixation assisted by X-ray fluoroscopy, computed tomography (CT)-based navigation, or intraoperative three-dimensional (3D) C-arm navigation.Methods This prospective cohort study was performed in 82 consecutive patients who underwent cervical pedicle screw fixation. The accuracy of screw insertion was assessed by postoperative CT scan with 3D reconstruction. The accuracy of screw insertion was assessed as: excellent (screw completely within pedicle); acceptable (≤ 1 mm screw outside pedicle cortex); poor (＞1 mm screw outside pedicle cortex).Results A total of 145 screws were inserted in 24 patients who underwent C-arm fluoroscopy. Of these, 96 screws (66.2%) were excellent, 37 (25.5%) were acceptable, and 12 (8.3%) were poor. One hundred and fifty-nine screws were inserted in 29 patients in the CT-based navigation group. Among these, 141 (88.7%) were excellent, 14 (8.8%) were acceptable, and 4 (2.5%) were poor. A total of 140 screws were inserted in 29 patients in the intraoperative 3D C-arm navigation group, of which 127 (90.7%) were excellent, and 13 (9.3%) were acceptable. No severe or permanent neurovascular complications associated with screw insertion were observed in any patient.Conclusione CT-based and intraoperative 3D C-arm navigation were similarly accurate, and were both significantly more accurate than C-arm fluoroscopy for guiding cervical pedicle screw fixation. They were able to accurately guide the angle and depth of screw placement using visual 3D images. These two techniques are therefore preferable for high-risk cervical pedicle screw fixation. The ease and convenience of intraoperative 3D C-arm navigation suggests that it may replace virtual-fluoroscopy and CT-based navigation systems in future clinical applications。

Abstract：Background Cervical disc arthroplasty is a new technique for treating degenerative cervical disease. Its goal is to avoid the degeneration of adjacent levels by preserving motion at the treated level. The aims of this study were to evaluate the radiologic outcomes of Bryan cervical disc replacement and the degenerative status of adjacent segments.Methods Twenty-two patients at a single center underwent discectomy and implantation of Bryan cervical disc. The mean follow-up period was 60 months (57-69 months). Twenty patients underwent single-level arthroplasty and two underwent arthroplasty at two levels. The levels of surgery included C3/4 (3 levels), C4/5 (2 levels), C5/6 (18 levels) and C6/7 (1 level). Radiographic evaluation included dynamic X-ray examination and magnetic resonance imaging (MRI) at baseline and at final follow-up.Results On X-ray examination, the range of motion (ROM) at the operated level was 7.2° (2.5°-13.0°) at baseline and 7.8° (1.0°-15.0°) at final follow-up (P ＞0.05). Heterotopic ossification around the prosthesis was observed in eight levels,and two levels showed loss of motion (ROM ＜2°). MRI showed worsening by a grade at the upper level in 2/22 patients,and worsening by a grade at the lower level in 3/22, according to Miyazaki's classification. No further impingement of the ligamentum flavum into the spinal canal was observed at adjacent levels, though the disc bulge was slightly increased at both the adjacent upper and lower levels at final follow-up.Conclusions Arthroplasty using Bryan cervical disc prosthesis resulted in favorable radiologic outcomes in this study.Disc degeneration at adjacent levels may be postponed by this technique。

Abstract：Background Selective anterior thoracolumbar/lumbar (TL/L) fusion and instrumentation in adolescent idiopathic scoliosis (AIS) patients with a structural major TL/L curve and a nonstructural minor thoracic curve is rarely reported. We investigate the correction results of these patients.Methods By reviewing the medical records and roentgenograms of AIS patients undergone selective anterior TL/Lfusion and instrumentation, Cobb angle, correction rate of the major and minor curves, coronal balance, lowest instrumented vertebra (LIV) tilt, coronal disc angle immediately below the LIV (LIVDA) and radiographic shoulder height (RSH) were measured and analyzed.Results Forty patients were included. For the major TL/L curve, the mean coronal Cobb angle before and after operation were 43.9° and 8.7°, respectively, with an average correction rateof 80.2% (P=0.000). While for the minor thoracic curve, the mean coronal Cobb angle before and after operation were 27.2° and 14.3°, respectively, with an average spontaneous correction rate of 47.4% (P=0.000). At final follow-up, the coronal Cobb angles of the major and minor curves were 13.7° and 17.1°, respectively, with a mean correction loss of 5.0° and 2.9°, respectively. The coronal balance before and after operations was 13.2 mm and 11.5 mm, respectively. At the final follow-up, it turned to 5.6 mm,which was much better than that after operation (P=0.001). The mean LIV tilt was 23.5° before operation, and was significantly improved after operation (8.3°, P=0.000). At final follow-up, it was well maintained (10.6°). The LIVDA averaged 3.5° before operation, and aggravated to 5.5° after operation (P=0.100) and 7.4° at final follow-up (P=0.012),respectively. The RSH was 7.3 mm before operation, 5.6 mm after operation, and 2.2 mm at the final follow-up. The RSH at the final follow-up was significantly improved compared with that after operation (P=0.002).Conclusions Selective anterior TL/L fusion and instrumentation can get good correction results of both curves, with good results of the coronal balance and RSH in AlS patients, while a larger LIVDA。

Abstract：Background Age-associated decrease in type ⅡA/B human skeletal muscle fibers was detected in human biopsies in our previous study. The relationship between change in muscle fiber typing and bone mineral density (BMD) is, however,unknown either cross-sectionally or longitudinally. We therefore conducted a cross-sectional study to investigate their correlation using human muscle biopsies.Methods Forty human subjects aged (53.4±20.2) years were recruited. Histomorphometric parameters of their muscle biopsies were measured by ATPase staining and image analysis, including average area percentage, fiber number percentage, mean fiber area, and area percentage of connective tissues. Hip and spine BMD was measured by dual-energy X-ray absorptiometry. Partial correlation with adjusting age was performed.Results Type ⅡB muscle fiber was found positively correlated with hip BMD irrespective to age and demonstrated significantly stronger relationship with BMD among all fiber types, in terms of its cross-sectional area (r=0.380, P=0.029)and size (r=0.389, P=0.025). Type ⅡA muscle fibers associated with hip BMD in mean fiber area only (r=0.420, P=0.015).Conclusions Type ⅡB muscle fiber may play an important role in maintaining bone quality. This may also be a relatively more sensitive fiber type of sarcopenia and osteoporosis. These findings further consolidate the muscle-bone relationship。

Abstract：Background Sacral nerve injury is a common complication of pelvic or sacral fractures. As the sacral nerve courser within the sacrum and has a complex relationship with the surrounding tissues, different parts of the sacral plexus injury have similar clinical symptoms and signs. Since lack of specific imaging technique in the diagnosis of sacral nerve injury,especially on multi-segment, multi-site, how to determine the preoperative location and extent of the sacral nerve injury accurately becomes a concem of the general orthopaedic and images practitioners. This study was conducted to gain an insight into the overall anatomical features of the sacral nerve (SN) on the same slice in high resolution computed tomography (HRCT) reconstruction and to determine the value of this information for the clinical diagnosis of related diseases.Methods Fifty healthy volunteers and 30 patients (40 sides) with SN lesions confirmed by surgery were scanned using a 16-slice helical CT scanner (Light Speed, GE, USA). Among the patients, 6 with intervertebral disk hernia (6 sides), 8with spinal stenosis (12 sides), 11 with pelvic trauma (14 sides), 4 with pelvic malignancies (6 sides), and 1 with sacral vertebral tuberculosis (2 sides). The SN multiplanar reconstruction was performed using a UNIX-based SCD4.1workstation where the image was set on the same slice. All images were stored in the Digital Imaging and Communications in Medicine format. The display of nerves in different sections was analyzed using a five-graded scale with coordinate curves of each individual score. The overall anatomic features visible on the slice were analyzed and the abnormalities of the lesions were studied.Results The image of the same slice clearly revealed the shape, running direction, thickness, tension and adjacent anatomy of the S1-S4 nerves. The rank of display rates in different sections was: outward-rotated oblique sagittal ＞outward-rotated oblique coronal ＞ oblique coronal plane ＞ coronal ＞ sagittal ＞ transverse section. The S5 nerve was partially displayed from the starting point to the segment around the posterior sacral foramen. The overall anatomy of the triangular sacral plexus was only revealed in the oblique outward-rotated sagittal section, while 100% of its individual rami,as well as two or three of the adjacent rami, were displayed from their starting points to the anterior border of the piriformis. The abnormalities included 39 sides of morphological change (97.5%), 38 sides of compression (95.0%), 35sides of adhesion (87.5%), 32 sides of displacement (80.0%), 34 sides of shrinkage (85.0%), 6 sides of thickening (15.0%), and 2 sides of abruption (5.0%).Conclusions The 16-slice CT multiplanar reconstruction was able to reveal the overall anatomic features of the SN on the same slice. The section of reconstruction was a crucial factor in determining the display capability of various sacral nerves. This technology was valuable in the diagnosis and management of related diseases。

Abstract：Background For partial-thickness tears of the rotator cuff, double-row fixation and transtendon single-row fixation restore insertion site anatomy, with excellent results. We compared the biomechanical properties of double-row and transtendon single-row suture anchor techniques for repair of grade Ⅲ partial articular-sided rotator cuff tears.Methods In 10 matched pairs of fresh-frozen sheep shoulders, the infraspinatus tendon from 1 shoulder was repaired with a double-row suture anchor technique. This comprised placement of 2 medial anchors with horizontal mattress sutures at an angle of .≤45° into the medial margin of the infraspinatus footprint, just lateral to the articular surface, and 2 lateral anchors with horizontal mattress sutures. Standardized, 50% partial, articular-sided infraspinatus lesions were created in the contralateral shoulder. The infraspinatus tendon from the contralateral shoulder was repaired using two anchors with transtendon single-row mattress sutures. Each specimen underwent cyclic loading from 10 to 100 N for 50 cycles, followed by tensile testing to failure. Gap formation and strain over the footprint area were measured using a motion capture system; stiffness and failure load were determined from testing data.Results Gap formation for the transtendon single-row repair was significantly smaller (P ＜0.05) when compared with the double-row repair for the first cycle ((1.74±0.38) mm vs. (2.86±0.46) mm, respectively) and the last cycle ((3.77±0.45) mm vs. (5.89±0.61) mm, respectively). The strain over the footprint area for the transtendon single-row repair was significantly smaller (P ＜0.05) when compared with the double-row repair. Also, it had a higher mean ultimate tensile load and stiffness.Conclusions For grade Ⅲ partial articular-sided rotator cuff tears, transtendon single-row fixation exhibited superior biomechanical properties when compared with double-row fixation。

Abstract：Background Costimulatory signals play a vital role in T cell activation. Blockade of costimulatory pathway by CTLA4Ig or CD40LIg have enhanced graft survival in experimental transplantation models yet mechanisms remain undetermined.We investigated the effects of CTLA4Ig and CD40LIg gene transfer on islet xenografts rejection in rats.Methods Human islets were infected with recombinant adenoviruses containing CTLA4Ig and CD40LIg genes and implanted beneath the kidney capsule of diabetic rats. Levels of blood sugar, morphological changes, and survival of grafts were recorded. Expressions of CTLA4Ig, CD40LIg and insulin were detected by immunohistochemical staining and cytokines levels were quantified by enzyme-linked immunosorbent assay (ELISA).Results Blood glucose levels in transplant rats decreased to normal level on the 2nd day post transplantation. The mean blood glucose in the control group, CTLA4Ig transfected group, CD40LIg transfected group and CTLA4Ig +CD40LIg cotransfected group increased on days 8, 24, 21, 68, post transplantation respectively. The grafts in control group, CTLA4Ig transfected group, CD40LIg transfected group and CTLA4Ig + CD40LIg cotransfected group survived for (8±1), (29±4), (27±3), and (74±10) days, respectively. Survival in CTLA4Ig + CD40LIg cotransfected group was significantly longer. Survivals of CTLA4Ig transfected group and CD40LIg transfected group were significantly longer than control group. In controJ animals, serum interleukin-2 and tumor necrosis factor a concentration significantly increased within seven days post transplantation. Haematoxylin eosin staining of grafts showed live islets in situ of transplant rats without inflammatory cell infiltration. Immunohistochemical staining confirmed the expression of insulin at islets in all experimental groups.Conclusions Transfer of CTLA4Ig and CD40Llg genes, especially the cotransfer of both, inhibits rejection of murine islet xenografts. Downregulated expressions of Th1 cells related cytokines might be related to the beneficial effects。

Abstract：Background The anterior cruciate ligament (ACL) is one of the most commonly injured knee ligaments. Even following ACL reconstruction, significant articular cartilage degeneration can be observed and most patients suffer from premature osteoarthritis. Articular cartilage degeneration and osteoarthritis development after ACL injury are regarded as progressive process that are affected by cyclic loading during frequently performed low-intensity daily activities. The purpose of this study was to perform a meta analysis on studies assessing the effects of ACL reconstruction on kinematics, kinetics and proprioception of knee during level walking.Methods This meta analysis was conducted according to the methodological guidelines outlined by the Cochrane Collaboration. An electronic search of the literature was performed and all trials published between January 1966 and July 2010 comparing gait and proprioception of a reconstructed-ACL group with an intact-ACL group were pooled for this review. Thirteen studies were included in the final meta analysis.Results There was no significant difference in step length, walking speed, maximum knee flexion angle during loading response, joint position sense and threshold to detect passive motion between the reconstructed-ACL group and the intact-ACL group (P ＞0.05). However, there was a significant difference in peak knee flexion angle, maximum angular knee flexion excursion during stance, peak knee flexion moment during walking and maximum external tibial rotation angle throughout the gait cycle between the reconstructed-ACL group and the intact-ACL group (P ＜0.05).Conclusions Step length, walking speed, maximum knee flexion angle during loading response, joint position sense and threshold to detect passive motion usually observed with ACL deficiency were restored after the ACL reconstruction and rehabilitation, but no significant improvements were observed for peak knee flexion angle, maximum angular knee flexion excursion during stance, peak knee flexion moment during walking and maximum external tibial rotation angle throughout the gait cycle。

Abstract：Objective To review the choices of allografts for bone defect reconstruction in acetabular revision surgery using the technique of impaction bone grafting.Data sources The data cited in this review were mainly obtained from articles listed in PubMed that were published from January 1993 to July 2009. The search terms were "impaction bone grafting", "particle size", "mechanical property"and "biological behavior".Study selection Articles relevant to the choices of allografts and their results for bone defect reconstruction on the acetabular side were selected.Results Different choices of allografts, including the particle size, process of irradiation or fat reduction, composition and particle grade, are made to improve the survival rate of a prosthesis in acetabular revision surgery. This review,which compares both mechanical and biological factors, summarizes the experimental and clinical results for different techniques.Conclusions Fresh frozen cancellous allografts with particle sizes ranging from 7 to 10 mm are a favorable choice for reconstruction of bone defects of American Academy of Orthopedic Surgeons (AAOS) types Ⅱ (cavitary defect) and Ⅲ(combined cavitary and segmental defect) on the acetabular side. A fat-reducing procedure with saline or solvent/detergent is controversial. Adding autologous marrow into irradiated allografts, which provides reliable mechanical stability and biological safety, may be a substitute for fresh frozen allografts. Cortical bone can be a supplementary material in cases of insufficiency of cancellous allografts. Cartilage should be excluded from the graft material. Further research is required to demonstrate the best particle grade, and randomized controlled trials in clinical practice are required to obtain more information about the selection of allografts。

Shensong Yangxin (SSYX) is one of the compound recipes of Chinese materia medica including 12ingredients such as Panax ginseng, dwarf lilyturf tuber,nardostachys root, etc. Small-scale randomized multi-centre clinical trials suggested that SSYX reduced the number of ventricular extrasystoles in patients with or without structural heart disease.1 Besides excellent antiarrhythmic efficacy,2 SSYX also improved bradycardia in some patients, which was evidenced by animal studies3 as well. However, the antiarrhythmic mechanisms of SSYX have not been fully understood.Our previous studies have explored effect of SSYX on many channels except hyperpolarization-activated cation channel encoded by human hHCN4 gene.4

Bartter syndrome type Ⅲ is a Bartter syndrome subtype, which has a group of autosomal-recessive inherited disorders with clinical characteristics such as renal salt wasting, hypokalemic metabolic alkalosis,elevated renin and aldosterone levels, with normal or low blood pressure.1 Unlike other subtypes that often begin in the neonatal period, type Ⅲ, due to mutations in the CLCNKB gene,2-4 is highly variable and usually presents as a "classic" Barrter variant characterized by an onset in early childhood and less severe or absent hypercalciuria and nephrocalcinosis.3

With the advent of shoulder magnetic resonance imaging (MRI), ganglion cysts adjacent to the superior labrum have been increasinglyrecognized.1-3The spinoglenoid notch cyst (SGNC) which causes suprascapular nerve compression has been well documented,3-16 and the association of superior labral anterior-posterior (SLAP) lesions with spinoglenoid cysts has gained more attention.2.5-16 Mostly, the SGNC is approached through7 the labral tear within the glenohumeral joint. Because this approach can not provide enough space to operate, normally the SGNC can only be decompressed. So we try to find approaches to expose and excise the SGNC exactly。

Acromioclavicular (AC) dislocations are common shoulder injuries. The classic mechanism of injury to AC joint is direct trauma caused by falls or blows to acromion with the arm abducted. According to Tossy et al,1 the degrees of AC dislocations are classified into types Ⅰ, Ⅱ, and Ⅲ. Tossy Ⅰ and Ⅱ are incomplete dislocations. Tossy Ⅲ is a complete dislocation with complete disruption of the AC and coracoclavicular (CC)ligaments, accompanied by marked upward migration of the lateral end of the clavicle. Typically, surgical treatment is needed for patients with Tossy Ⅲ. It is the best solution to restore the anatomy of AC joint. There are many surgical techniques that had been described in the preceding articles. Every surgical method has its limitations。

Intraosseous lipomas are rare, benign bone tumors,comprising less than 0. 1% of all primary bone tumors.Common sites of intraosseous lipomas include the os calcis and the metaphyses of the long bones of the lower limbs.2 Cases involving the spine are extremely rare; a meta-analysis of 206 cases reported that intraosseous lipomas involving the spine (including the sacrum)accounted for 6% of all cases.2 A review of the English literature reveals only 14 reported cases involving the spine (Table). The case involving the upper cervical spine (C 1 and C2) is presented, followed by a discussion of the diagnosis and treatment strategies。

Lymphomatoid granulomatosis (LG) is a rare EpsteinBarr virus (EBV)-associated systemic granulomatous disease that is characterized by an angiocentric and occasionally angiodestructive polymorphic cellular infiltrate. It most frequently affects the lungs, kidneys,and brain.1,2 Usually the lesions are multi-systemic and multifocal. Central nervous system (CNS) involvement occurs in approximately 30% of affected patients, and patients may present with nonspecific neurological symptoms.3 Although CNS lesions usually appear as a secondary metastasis of pulmonary lesions, in rare conditions, it may be the initial or only manifestation of the disease. In this report, we describe two cases presenting with unifocal mass in the brain, histologically confirmed to be LG,

To the editor: Ventral spinal schwannoma is not a frequently encountered disease and its surgical treatment is difficult.1,2 It has not been reported that the arachnoid adhesions caused by SURGICEL after operation for ventral spinal schwannoma.A 45-year-old man was admitted to our clinic with complaints of intermittent lumbar pain for 12 months. Physical examination: The patient's lower extremity muscle strength was Ⅲ-Ⅳ grade, the bilateral knee tendon reflexes was hyperactive, the bilateral Babinski sign was positive, the sensory dysfunction level was at T11, the anal reflex was positive, the bilateral cremasteric reflex was positive。