0.05). Conclusion Our finding suggests that it is reasonable to operate on elderly patients with lumbar stenosis who are different in body mass index, because little relation has been found between body mass and surgery outcome.

Among all the road traffic injuries(RTI ),limb and spine fractures have a very high inci-dence.They can be caused by a variety of traumatogenic mechanisms,of whi ch crash is the most common.The distribution of types of fracture in RTI assumes a centrifugation-like p attern.Multiple fractures,homola teral limb injuries and violence-conducted in juries are common.The priority in RTI emergency is to treat serious concu rrent injuries and life-threatening comp lications.Only after the overall condition of the victim get stabilized can open injuries and fractures be treated ac tively.To treat victims of fracture s caused by RTI,especially those with a poor overall condition or an old age,appl ication of external fixation,espec ially a unilateral one,is a good consider-ation.And application of lockable i ntramedullary nailing to treat long tubular bone fractures has proved ve ry satisfactory.As for pelvis fractur es caused by RTI,external fixation c an be used initially while massive hemor-rhage resulted from the injury shoul d be treated vigorously.Internal fixation should be adopted as soon as th e vital signs get stabilized.To treat spine and spinal cord injuries,titanium a lloy is the first choice for fixation material.In most cases,anterior cervical fix ation and fusion with steel plate and screw is advisable for treatment of f ractures of cervical spine,while posterior i mmobilization with screw through pedicle of vertebra is usually suggested for treatment of fracture-dislocation of thoracolumbar vertebrae.

Objective To prevent wrong diagnosis and treatment of chronic inflammatory demyelinating polyneuritis(CIDP) by analyzing the clinical characteristics of CIDP and spine degeneration disorders. Methods In order to distinguish CIDP from spine degeneration diseases, we retrospectively reviewed 16 CIDP patients from December 2000 to December 2003 (male 10, female 6; range 38-58 years old, mean 49.1 years old) who were misdiagnosed as spine degeneration diseases. The duration of the disease was 2 months to 2 years and 8 months, with an everage of 106 months. All clinical data of the 16 patients were analyzed. The data included clinical manifestation, physical examination, protein content of cerebrospinal fluid (CSF) and upper-lower extremity electrophysiologic study(EPS). Comparing the clinical charateristics of CIDP with those of spine degeneration disease. Results All 16 patients of CIDP sufferred limbs sensory disturbance or abnormality, walking difficulty. Upper or lower extremity were involved at equal pace and symmetry; limb tendon reflexes weakened or dissappeared, but limbs muscular atrophy were not significant. X-ray showed degeneration of cervical or thoracic and lumbar spine; MRI showed that there were disc herniation in different intervertebral. The content of protein of CSF remarkably increased(mean 479.9 mg/L). There were significant deviation compare to normal. Electrophysiology study found that sensory nerve action potential(SNAP) wave amplitude were descending; motor nerve conduction velocity(MNCV) were slower. Conclusion We could rightly diagnose and distingnish CIDP from spine degeneration diseases by analyzing clinical manifestation, physical examination, cerebrospinal fluid and electrophysiological study. [

Objective To retrospectively analyze the results of closed reduction and static trans-articular fixation with unilateral external fixators in the treatment of unstable distal radius fractures.Methods From June 2000 to March 2005,45 patients with 50 unstable distal radius fractures were treated with closed reduction and static transarticular fixation by unilateral external fixators.Their average age was 44.8 years(15 to 78 years).All the fractures were classified with AO-scheme.There were five A3-fractures,four B3-fractures,three C1-fractures,nine C2-fractures and 29 C3-fractures in 24 cases.Follow-ups lasted from 8 to 48 months(averaging 20 months).Results The time of bone healing was 6 to 8 weeks(averaging 7.6 weeks).At the latest follow-up,the radiological outcomes were excellent in 42 fractures(39 patients)and good in eight fractures(six patients)according to the Sarmiento rating system modified by Ste wart et al.The functional results included 37 excellent cases(34 patients),nine good ones(eight patients)and four fair ones(three patients)according to the Gartland-Werley assessment.There were only four cases of superficial pin site infection settled with oral antibiotics and mild disinfectants.Conclusions Closed reduction by manipulation and static transarticular fixation with unilateral external fixators is an effective method to treat severely comminuted distal radius fractures caused by high-energy injury.Radial nerve injury and iatrogenic fracture of the 2nd metacarpal bone can be avoided,pin tract infection and pin loosening can be decreased,and early postoperative mobilization of hand can be facilitated by insertion of external pins at appropriate sites.It is unnecessary to apply supplementary bone grafting to promote bone healing.

Objective To evaluate the biomechanical featu res of the HOIST in the treatment of lumbar spondylolisthesis.Methods Seven fresh cadaver specimens from L 2 to sacrum was used in the study.Each specimen was tested in five states:intact state as the control,spon dylolisthesis model by Panjabi meth od without fixation,spondylolisthesis model fixed with HOIST device,fatigued test of the HOIST and fixed with DICK system.During the experiment,the flexion,extension,bilateral bending and axial rotation loading we re applied to the specimens and measure d with three dimensional analysis ap paratus.A fatigue process of HOIST device was carried out with multifunctional test system(MTS 858,American).The ranges of motion(ROM)of spinal segments were determined with two special cameras and t test was used in statistical analysis.Results The ROM in spondylolisthesis state was significantly greater than that o f the others(P0.05).The difference among two HOIST grou ps and DICK group was not significant at the0.05level except the ROM of left axia l rotation(P

Objective To observe the expansion of transverse width of post screw-implantation in the pedicle and assess the effect of the relative diameter and BMD on the expansive rate. Methods There were 48 vertebral bodies, and 96 pedicles, obtained from 4 human cadaveric T2～L1 specimens (the mean age of 41 years). The BMD(A), pedicle width (B) and height were measured respectively. According to groups of BMD(A1:0.44～0.52 g/cm2;A2:0.52～0.70 g/cm2;A3:0.70～0.92 g/cm2 and the relative diameter(screw/pedicle)(B1:40%～55%;B2:55%～70%;B3:70%～85%), the tests were classified into 9 groups (A1B1?A1B2 ?A1B3?A2B1?A2B2?A2B3?A3B1?A3B2 and A3B3). The implantation procedure was carried out under the uniform standard. Results The number of valuable date was 85, while 11 dates were excluded, including 4 burst pedicles in A3B3 group. According to the statistical analysis, the pedicle width was expanded after implantation. The expansive rate of pedicle width was influenced significantly by the relative diameter and BMD(P

Objective To study the short-term outcome of transforaminal posterolateral endoscopic discectomy and radiofrequency annuloplasty in patients with discogenic low back pain. Methods A total of 25 patients with discogenic low back pain,who were diagnosed by provocative discography,received transforaminal posterolateral endoscopic discectomy and radiofrequency annuloplasty in our hospital. The VAS scores determined before and 6 months after the operation were compared in the patients. Their MacNab scores were also evaluated at 6 months postoperation. Results After the surgery,2 patients who had ruptured intervertebral discs (L5-S1) developed sunburn syndrome,and then was relieved by pulsed electrical stimulation for one week. The patients were followed up for 6-10 months,during which no other postoperative complications occurred. The mean VAS score of this series decreased significantly after the treatment,and kept being reduced in 6 months [preoperation:6.24?0.97,1,3,6 months after the operation:0(0~2); Kruskal-Wallis rank-sum test,H=61.680,P=0.000]. Four patients showed lower limbs pain before the treatment and were relieved after the surgery. The evaluation of MacNab score showed excellent in 11 pateints,good in 12,and fair in 2,suggesting an effective rate of 92.0%(23/25). Conclusions Transforaminal posterolateral endoscopic discectomy plus radiofrequency annuloplasty is effective for discogenic low back pain in a short term.

Objective To discuss the design of arthroscopic reconstruction of posterior cruciate ligament (PCL) with quadriceps tendon fixed by a patellar block and an allograft bone plug, and its clinical outcome. Methods Thirteen patients suffering from PCL injury were treated by the technique mentioned above. The connection between quadriceps tendon and superior patellar pole was preserved in the harvest process of quadriceps tendon. The femoral tunnel was made like a bottle neck, which was clogged with the patellar bone block. The quadriceps tendon strip was fixed by an allograft bone plug pressed into the tibial tunnel. Their functional recovery was evaluated by Lysholm scoring and IKDC(International Knee Documentation Committee) criteria. Results In the average follow-up period of 19 months, there were not any severe nerve or blood vessel lesions, or failures of transplanted ligament None of the patient complained of knee instability after the operation. The pain was relieved in most patients, but three complained of pain after knee movement A little calcification was found in the quadriceps tendon at the superior patellar pole one year after the operation in the X-ray of a patient There was significant difference in Lysholm scale between pre-operation and post-operation (P

Objective To observe the nerve regeneration and functional recov er y in canines, in which a large gap was made in the continuity of the sciatic ner ve and the gap was repaired by acellular allograft through chemical extraction. Methods 15 canines were divided into acellular nerve allografting group (ANG, 6 canines), autografting group (AG, 6 canines) and fresh nerve allografting group (FNG, 3 canines). The sciatic nerves on the right side of all animals were expos ed and 5.0 cm long segments were removed from the mid-thigh level and replaced by one of the three types of grafts. The motor recovery was assessed by gait tes t at month 6 postoperatively. The sensory and motor conducting functions were as sessed by electrophysiological experiments. The nerve regeneration was revealed by morphological studies on the grafting segments, the distal tibial nerves and motor end-plate of the target muscle. Results All the animals in ANG and AG gro ups had similar patterns of right posterior limb gait cycle and right ankle move ments. Stimuli (1.0-2.0 mA, 0.1 ms, 1.0 Hz) to the sciatic nerves proximal to t he implanted segment resulted in motor-evoked potentials recorded from the musc ulus triceps surae. The motor conducting velocities of the grafting segments wer e on average 47.2 m/s in ANG, 60.9 m/s in AG and 122.0m/s in normal controls. St imuli (5.0-10.0 mA, 0.2 ms, 1.9 Hz) to the right distal tibial nerves resulted in sensory-evoked potentials recorded from the cortical area in all the canines in ANG and AG groups. Axons regeneration and Schwann cells migration had reoccu pied the empty basal lamina tubes of the acellular allografting segments without excessive sign of inflammation. ANG and AG had similar nerve regeneration with massive large nerve fibers in the distal tibial nerves and vast motor end-plate in the target muscle. Conclusions The patterns of functional recovery and nerve regeneration tend to be similar 6 months after implantation in the canines, in which a 5.0 cm gap in the continuity of the sciatic nerve is repaired by either chemical acellular nerve allografting or autografting.

Objective To evaluate the clinical effectiveness of minimally invasive external fixation in the treatment of intertrochanteric fractures of the femur in high-risk patients. Methods By using a monolateral external fixator with oblique pin-insertion, we treated 77 consecutive elderly patients (mean age, 71.3) with intertrochanteric fractures of the femur associated with at least one kind of severe systemic diseases from June 1996 to June 2004. Fractures included 70 cases of anterograde intertrochanteric fracture (According to the Evans classification, there were 5 cases of type Ⅰ fracture, 11 cases of type Ⅱ, 34 type ⅢA, 9 type ⅢB, and 11 type Ⅳ.) and 7 cases of retrograde intertrochanteric fracture. A total of 8 patients were combined with multiple injuries. Results A follow-up was made for 5~60 months (mean, 24.3 months). Complete bone union was achieved in all the patients within a period of 8~20 weeks (mean, 12 weeks). Postoperatively, no non-union or coxa vara occurred. According to the Harris hip scores, 49 patients were classified as “excellent” results, 21 as “good”, and 7 as “poor” (all of which were fatal cases), the “excellent-and-good” rate being 91%. Conclusions Minimally invasive external fixation is an alternative to open internal fixation in the management of intertrochanteric fractures in high-risk elderly patients, especially suitable to those with multiple injuries.