Objective To evaluate the clinical results and safety of pedicle screw fixation for the treatment of spinal disorders. Methods From January 1988 to December 1999, 475 patients (216 males amd 259 females) with an average age of 49.1 years old in the male and an average age of 48.7 years old in the female, underwent pedicle screw fixation for spinal disorders. Diagnoses included 217 cases of spondylolisthesis, 76 lumbar stenosis, 32 degenerative lumbar spine instability, 72 thoracic or lumbar spine fractures, 60 scoliosis, and 18 others. The instrumentations were as follows: Dick 55 cases, Steffee 79 cases, CD 54 cases, RF 82 cases, DRFS 59 cases, TSRH 29 cases, USS 19 cases, SOCON 44 cases, Dynalock 24 cases, Diapson 22 cases, Tenor 5 cases, and CDH 3 cases. The fusion ranges involved one segment in 310 cases, two segments in 96 cases, and three segments in 9 cases. Hooks were applied in 60 cases. Results Four hundreds and twenty eight patients(90.l%) were followed up for (6.0?3.7)years. In the patients of degenerative spondylolisthesis, spondylolysis, lumbar stenosis, degenerative lumbar instability and thoracolumbar fracture, the amelioration of nerve function was 79.9%, 87.9%, 77.0%, 89.3%and 62.7%; the improvement of spinal motion was 90.5%, 90.9%, 83.6%, 92.9%and 52.5%; the amelioration of low back pain was 89.9%, 87.9%, 85.2%, 89.3%and 84.8%; and the amelioration of leg pain was 93.9%, 90.9%, 93.4%, 92.9%and 79.7%respectively. The mean reduction rate of degenerative spondylolisthesis, spondylolysis and spinal fracture was 90.5%, 87.9%and 91.5%respectively. The SOCON technique showed the highest reduction rate of an average of 92.3%, followed by RF of 90.8%, and Dick, Steffee and DRFS of 81.2%, while other instrumentations showed no satisfactory result in reduction. Complications occurred in 90 cases, in which 26 cases occurred during operation with the incidence of 6.1%, while 64 occurred after operation with the incidence of 15.0%. Conclusion Pedicle screws provide fixation of short segments with satisfactory clinical results and relatively high fusion rate. Perfect surgical technique is the key to reduce the incidence of complications.

Obiective To evaluate the value of allograft bone for acetab ular and femoral reconstruction in THA revision surgery. Methods A total of 19 p atients underwent reconstruction of acetabular and proximal femoral bone defects from June 1996 to December 2000 were reviewed. Eleven of the patients were men and 8 women with a mean age of 66.5 years and 63.2 years respectively at the t ime of resision surgery. According to AAOS system, the acetabular bone defects w ere classified into type I in 2 hips, type II 10 hips and type III 4 hips, and o n the femoral side, there were type I in 3 hips, type II 11 hips and type III 2 hips respectively. The reconstruction of bone defect of acetabulum included stru ctural allograft in 3 hips, impacted morselized allograft in 3 hips, and metal w ire mesh with morselized allograft in 3 hips. In all 3 of femoral segemental def ects, the reconstructions of the proximal femoral bone defects were done with st ructural allografts. Metalwire mesh with morselized allograft for femoral bone d efects were performed in 2 cases and morselized allogratts alone for femoral bon e defects in 4 cases; both acetabular and femoral bone defects were reconstruct ed with impacted morselized allografts in 6 cases (7 hips), and 4 patients with no bone grafts; Harris score system and radiograph were used for the final eva luation. Results Ninteen patients were followed up for an average period of 46 m onths (ranges, 6 to 68 months), Harris score improved from 42.7 points pre rev ision to 82.7 points at final follow up, the incorporation of allografts bone in 15 patients (16 hips) were noticed radiographically in all but one hip was fo und reabsorption of the structural allograft and radiolucents were found in the other 3 patients. No infection was encountered in this series. Conclusion If th e different types of bone defects were properly identified and suitable allogrft s adopted, reconstruction of bone defects with allografts during the THA revisi on surgery is a useful and reliable method. [

Objective To investigate the expression of the basic fibroblast growth factor (bFGF) in normal and degenerated human intervertebral discs in order to determine whether bFGF is related to degeneration of the intervertebral disc. Methods The specimens of the intervertebral discs from 11 male and 19 female patients undergone lumbar disc herniation surgery (observation group) and 6 patients with scoliosis following anterior release (control group) were harvested. The tissues were histologically observed to confirm their degenerated or normal status and then conducted for the expression of bFGF and its mRNA with immunohistochemistry and in situ hybridization. Results In the observation group, all the samples were found to be degenerated disc tissue, and the positive rate of the expression of bFGF was 90% (27/30) with immunohistochemistry and 20% (6/30) with in situ hybridization. In the control group, all the samples were shown to be normal disc tissues, and had negative expression of bFGF with immunohistochemistry and in situ hybridization. The positive rate of the expression of bFGF showed significant difference between the two groups. Conclusion The expression of bFGF showed significant difference between the degenerated and normal intervertebral discs, which indicated that the bFGF might promote proliferation of chondrocyte and synthesis of extracellular matrix in the degenerated discs as a proliferation stimulating factor.

Objective To measure and compare the insertion torque and pullout strength of newly designed general spine system(GSS) screws with those of SOCON and CCD pedicle screws in normal human cadaver vertebrae, and to evaluate the screw purchase of GSS pedicle screws. Methods Twenty seven lumbar vertebral bodies obtained from 6 fresh normal male cadavers were classified into 3 groups randomly, 18 pedicles per group. GSS, SOCON and CCD pedicle screws were implanted into the pedicles of each group respectively. Pedicle screws were inserted with a torque screwdriver. Each screw was extracted axially from the pedicle at a rate of 5 mm/min until failure using a material testing machine(SWD-10, Changchun, China). Force data were recorded and analyzed using a one way ANOVA. P

0.05). In Group 2, the mean maximum pull out strength of the GSS screws was 127% of that of the CCD control screws, while the mean maximum pull out strength of the TSRH screws was 64% of that of the CCD control screws. The mean maximum pull out strength of the GSS screws was significantly higher than that of the TSRH screws (P0.05). Conclusion GSS screws offer better anchoring in revision surgery than most of the currently used screws do.

Objective To determine the best method of revision for failed pedicle screw by investigating the change in maximum insertional torque and axial pullout strength after placing a larger diameter and/or longer screw or augmenting the failed hole with bone shims or PMMA. Methods Six fresh male adult cadaveric spines from T10-L5 were harvested. These specimens, aging from 23 to 51 years with an average of 36.7 years, were divided into six groups: 1)Using a larger diameter screw; 2)Using a longer screw; 3)Using a larger and longer screw; 4)Augmenting with bone shims; 5)Augmenting with PMMA; and 6)Reinsertion after being backed out. The first three groups were subdivided into two groups. Maximum insertional torque and axial pullout strength of each original screw were recorded as control data. Change of maximum insertional torque and axial pullout strength between original and corresponding revision screws were noted. Measurements were analyzed using one-way ANOVA statistically by SPSS10.0. Insertional torque change after simply removing and replacing a 5.0 mm?40 mm screw was also measured. Results Among the changes in pedicle dimensions, the greatest improvement in peak insertional torque and axial pullout strength occurred when using a 2 mm larger and 10 mm longer screw, with an increase of 37.06% and 18.22%; a 2 mm larger screw increased peak insertional torque and axial pullout strength by 20.15% and 19.99% respectively, while a 1 mm larger and 5 mm longer screw increased by 19.23% and 10.07% respectively; use of a 5 mm or 10 mm longer screw decreased peak insertional torque by 32.80% and 14.02% respectively, with axial pullout strength down by 27.36% and up by 43.25% respectively. Use of bone shims caused a decrease of the insertional torque and axial pullout strength by 14.99% and 29.34% respectively. Hole augmentation with PMMA lead to a significant increase in insertional torque but a decrease in axial pullout strength by 37.40%. Simply removing and replacing an original screw resulted in a decrease in insertional torque by 34.22%. Conclusion Revision for pedicle screw is most effective when using a 2 mm larger diameter screw, next by using a 1 mm larger diameter and 5 mm longer screw. Use of a bone shim should be avoided. The efficacy of hole augmentation with PMMA need to be further investigated.

Objective To explore the indications, intraoperative problems and management of its complications of the microendoscopic discectomy (MED) in the treatment of lumbar intervertebral disc herni-ation through posterior approach. Methods 242 cases of lumbar disc herniation treated by MED were re-viewed retrospectively from March 2000 to March 2002. Of the 242 cases, there were 171 males and 71 fe-males aged from 19 to 71 years with an average of 34 years. Among them, the lesions were located at single level in 193, double levels in 46, and three levels in three. All of 242 patients were examined with CT, 48 of which were performed MR. Results 205 herniated discs of the single level were removed, 36 of the double levels, and one of the three levels. It was average 2.2 days for the patients to get off bed ranging from 24 hours to 6 days. Postoperative hospitalization was from 3 to 12 days with an average of 5.2 days. Among the intraoperative complications, dural tear happened in four, nerve root injury in two, and mistakes of localiza-tion in one. While in postoperative complications, there was discitis in one which happened at three weeks postoperatively, and was cured with antibiotics and ambulation for five months. All incision healed in one stage, except one suffered from superficial infection and healed by dress changing. All cases were followed up for 2 to 15 months with an average of 6 months. The average period for the patients retuning to daily life was 3.6 weeks, and 52.4% of the patients restored to previous work. According to Macnab's evaluation sys-tem for clinical outcomes, the results showed excellent in 183, good in 44, fair in 13 and poor in two, so the rate of excellent and good was 94%. However, there were two cases converted to open operation because of compressive neurological dysfunction. Conclusion Appropriate control of indications and skillful surgical technique are the key points to decrease the complication, and to improve the curative effect.

[Objective]To explore the apparatus assembly,operative methods,post-operative management procedure and the effect of Ilizarov's technique of distraction histogenesis to correct the severe compound knee joint deformities (more than two deformities of knee joint such as knee flexion contracture with genu varus and limb shortening).[Method]According to Ilizarov technique of distraction histogenesis,three dimensional knee joint distraction apparatus together with limb lengthening accessories for simultaneous lengthening of the lower limb were designed.In accordance with different types of compound knee joint deformities and the positions of skeletal deformities,across knee joint distraction apparatus was applied with simultaneous distal femoral or proximal tibial osteotomy.Soft tissue contracture of knee joint along with co-existing skeletal deformity and shortening were simultaneously corrected by slowly turning the corresponding distraction rods at seven days after the operation.During the period of distraction,patients can walk with partial weight bearing.After healing of the distraction bone regenerate,the distraction apparatus was removed and the knee joint brace applied for the patients to walk for about 3～6 months.From May 1996 to Feb 2004,compound knee joint deformities were corrected in 14 patients aged between 5 and 41 years old with an average age of 27 years and etiologies of 7 kinds,in whom four cases had developmental deformities of the knee joint caused by epiphyseal injury or infection in infancy and ten cases caused by other reasons.[Result]The time of joint distracting and bone healing was 80~390 d,average 154 d.All cases had satisfactory correction of severe compound knee joint deformities such as knee flexion contracture,genu varus,genu valgus,limb shortening and rotational deformity with good walking function.None had complications such as severe pin tract infection,injury to blood vessels and nerves and non-union.But a different extent of knee joint stiffness occurred.[Conclusion]Ilizarov technique of distraction histogenesis can be used to correct severe compound knee joint deformities and limb length inequality.It follows with biological principles,makes achievements unattained by traditional orthopedic surgery and have good prospect of application.

BACKGROUND: Measurement is frequently performed in diagnosis of orthopedics, and involved in various correction andtreatment of congenital and acquired deformity. The perioperative measurement of affected knees of patients undergoing totalknee replacement (TKR) is significant.OBJECTIVE: To clinically evaluate and validate 4 domains of a self-designed simple medical orthopedics tool measurementapparatus (OTMA) according to the results of Cybex Norm measurement system, an international standard measurementapparatus, for osteoarthritis patients during TKR.DESIGN, TIME AND SETTING: Stratified, randomized, Controlled experiment. The study was performed at the Department ofOrthopedics, Peking Union Medical College Hospital between October 2004 and March 2006.PARTICIPANTS: A total of 47 patients (66 knees) with osteoarthritis of knee, undergoing TKR, were selected and randomlydivided into 2 groups: OTMA group (n=24, 33 knees) and Cybex group (n=23, 33 knees).METHODS: Range of motion (ROM) of two groups was measured respectively using OTMA and Cybex Norm, before and 3months after treatment as well as the final time of 1-year follow up. The ROM results were evaluated by Hospital for SpecialSurgery Knee Score (HSS) scale for knee joint. The visual analog scale and MOS 36-item Short Form Health Survey (SF-36)scale were filled to verify the applicability and reproducibility of OTMA. The correlation of measurement results and subjectivescale evaluation was analyzed to verify the evaluation efficiency of OTMA.MAIN OUTCOME MEASURES: Coincidence of ROM of two groups at different time points; correlation of scale scores and ROM.RESULTS: All patients were followed up. The coincidence rate of measurements between OTMA and Cybex Norm was 98.3%,HSS scale scores were increased with increasing ROM in both groups (P < 0.01). Correlation analysis showed that ROM washighly correlated with scale results, consistent with the clinical manifestation of patients.CONCLUSION: The measurement process was accepted by all patients, and could be performed repetitively. OTMA displaysprecise measurement, which could reflect clinical symptoms of patients and assist clinical diagnosis.

BACKGROUND:Cybex NORMTM isokinetic dynamometer exhibits precise measurement,but the operation is too complex and the cost is too high to apply on routine examination.OBJECTIVE:To compare orthopedics tool measurement apparatus(OTMA)and Cybex NORMTM dynamometer in evaluating the range of motion after the treatment of shoulder.hip and knee joint diseases,and to verify tlle practical value of OTMA as a scientitic patent achievement.DESIGN,TIME AND SETTING:Clinical randomized control trial was carried out in the Rcsearch Center for Orthopaedics and Artificial Joint.Peking Union Medical College Hospital from October 2004 to March 2005.PARTICIPANTS:A total of 121 patients were randomly divided into two groups.OTMA group comprised 22 patients with shoulder periarthritis(22 shoulders).1 5 patients with avascular necrosis of the femoral head(21 hips),and 24 patients with knee osteoarthritis(33 knees).Cybex group comprised 21 patients with shoulder periarthritis(21 shoulders),16 patients with avascular necrosis of the femoral head(21 hips),and 23 patients with knee osteoarthritis(33 knees).METHODS:Two groups patients were treated with OTMA or Cybex NORMTM dynamometer,respectively,the range of motion was measured before treatment and 3 months,1 year after treatment.The Hospital for Special Surgery(HSS)knee rating scale,Karisson evaluation criterion of shoulder function and Harris hip score were applied to evaluate the patients,Visual analog scale(VAS)pain scale and short-form health survey(SF-36)were also used in this study.MAIN OUTCOME MEASURES:The range of motion in shoulder,hip and knee;Karlsson,Harris and HSS scores;VAS pain score and SF-36 score.RESULTS:OTMA measurement had a coincidence with Cybex NORMTM dynamometer measurement as 98.3%.All patients accepted and completed the measurement.The range of motion Was associated with HSS.Karlsson and Harris scores (P=0.002).CONCLUSION:According to three-dimensional space measurement,the digital OTMA may obtain the outcomes similarly with Cybex NORMTM dynamometer,it is also near to the practical value of joint angles.