BACKGROUND:Posterior lumbar interbody fusion is a typical therapeutic method of lumbar degenerative disease. Present studies suggested that adjacent segment degeneration occurs after fusion. Recently, more and more scholars paid attention to the development of non-fusion of the spine. ＜br> OBJECTIVE:To compare clinical effects of Dynesys dynamic stabilization system fixation and posterior lumbar interbody fusion in treatment of lumbar degenerative disease. ＜br> METHODS:From July 2009 to July 2011, clinical data of 56 patients with lumbar degenerative disease were retrospectively analyzed. There were 28 cases of Dynesys dynamic stabilization system fixation, and 28 cases of posterior lumbar interbody fusion. Operation time, bleeding volume, and postoperative hospitalization time were compared in both groups. Visual analog scale was used to assess pain. Oswestry disability index was utilized to evaluate clinical effects. ＜br> RESULTS AND CONCLUSION:A total of 56 patients were fol owed up for 18-24 months. Visual analog scale and Oswestry disability index scores were significantly improved at 12 months after treatment in both groups (P＜0.01). Significant differences in operation time, bleeding volume, and postoperative hospitalization time were detected between both groups (P＜0.01). Dynesys dynamic stabilization system group was better than posterior lumbar interbody fusion group. Range of motion was better in the Dynesys dynamic stabilization system group than in the posterior lumbar interbody fusion group (P＜0.01). During fol ow-up, nail rope system and polyester sleeve loose were not detectable in the Dynesys dynamic stabilization system group. These results verified that compared with posterior lumbar interbody fusion, Dynesys dynamic stabilization system for lumbar degenerative diseases has a high safety and smal trauma, and can keep advantages of a fixed segment, and exert a certain effect on degeneration of intervertebral disc in the adjacent segment.

Objective To investigate biomechanical analysis of poly DL-lactic acid (PDLLA)biodegradable fusion cage of the lumbar vertebrae in vivo degradation. Methods Forty-eight healthy adult porcine were divided into experimental group and control group at randomly. PDLLA cage full of autogenous bone and bone block with the same size were planted in L45 intervertebrae respectively. At the 1st, 3rd, 6th,9th, 12th, and 18th month postoperatively, the animals were sacrificed and the surgical spinal segment was observed. The range of motion (ROM) was measured. Results The ROMs had no statistical differences at all motion directions between the two froups at the 1st month postoperatively. But the ROMs of experimental group were greater than those of control group at extension direction at the 3rd and 6th month postoperatively. The ROMs of extension was the greatest while the ROMs of right rotation was the least in both groups. At the 9th month postoperatively: the ROMs of experimental group greater than those of control group except at rotation. The ROMs of right rotation was the least in both groups. The greatest ROMs was at extension in experimental group and at right bending in control group. ALL ROMs tended to decrease and the ROMs of extension had comparability between tow groups. At the 12th month postoperatively, experimental group had greater ROMs at extension and left bending and less ROMs at other directions. Likewise statistical differences showed only at extension. 18th month postoperatively all ROMs were close between two groups. Conclusion After PDLLA cage is planted, the first 3 months is autologous stable stage. The period of 3rd to 6th months is easily released stage. The operative segments are stable from 9th to 12th months and acquired.Critical period between stability and instability is from 6th to 9th months. Bone fusion is from 12th to 18th months postoperatively.

Objective: To explore the characteristics and methods of different fixation methods and prevention of open knee joint fracture. Methods: The data of 86 cases of open knee joint fracture admitted from January 2002 to December 2015 in Department of Orthopaedics, Affiliated Hospital of Chengdu University were analyzed retrospectively.There were 65 males and 21 females aged of 38.6 years. There were 38 cases treated with trans articular external fixation alone, 48 cases were in the trans articular external fixation plus auxiliary limited internal fixation group. All the patients were treated according to the same three stages except for different fixation methods. Observation of external fixation and fracture fixation, fracture healing, wound healing and treatment, treatment and related factors of infection control and knee function recovery. χ² test was used to analyze data. Results: Eleven patients had primary wound healing, accounting for 12.8%. Seventy-five patients had two wounds healed, accounting for 87.2%. Only 38 cases of trans articular external fixator group had 31 cases of articular surface reduction, accounting for 81.6%; Five cases of trans articular external fixator assisted limited internal fixation group had 5 cases of poor reduction, accounting for 10.4%; There was significant difference between the two groups (χ²=44.132, P<0.05). Take a single cross joint external fixation group, a total of 23 cases of patients with infection, accounted for 60.5% of external fixation group; trans articular external fixation assisted limited internal fixation group there were 30 cases of patients with infection, accounting for the assistance of external fixator and limited internal fixation group 62.5%; There was significant difference between the two groups(χ²=0.035, P>0.05). Five cases of fracture nonunion cases of serious infection, patients voluntarily underwent amputation. The Lysholm Knee Scale: In the external fixation group, 23 cases were less than 50 points, accounting for 60.5%, 15 cases were more than 50 points, accounting for 39.5%, external fixation and limited internal fixation group 20 cases were less than 50 points, accounting for 41.7%, 28 cases were more than 50 points, accounting for 58.3%; There was significant difference between the two groups(χ²=1.279, P>0.05). Conclusions Prevention and control of infection is a central link in the treatment of open fracture of the knee. Trans articular external fixator plus limited internal fixation is an important measure to treat open fracture of the knee-joint.

Objective:To explore the feasibility and advantages and disadvantages of local anesthesia for TiRobot-assisted removal of sacroiliac screws by comparison with general anesthesia for TiRobot-assisted removal of sacroiliac screws.Methods:A retrospective study was performed in 39 patients with posterior pelvic ring fracture-dislocation who had undergone removal of percutaneous sacroiliac screws after fracture union from January 2017 to December 2020 at Department of Orthopaedic Surgery, Hospital Affiliated to Chengdu University. Their sacroiliac screws were removed with TiRobot assistance under local anesthesia (LA group) or general anesthesia (GA group). In the LA group of 18 cases, there were 10 males and 8 females, aged (43.3 ± 8.4) years (from 25 to 58 years); in the GA group of 21 cases, there were 12 males and 9 females, aged (44.9 ± 9.0) years (from 23 to 60 years). The 2 groups were compared in terms of time for planning screw removal path, fluoroscopy frequency, fluoroscopy time, operation time, anesthesia time, anesthesia cost, postoperative visual analogue scale (VAS) and postoperative ambulation time.Results:There was no statistically significant difference in baseline data between the 2 groups, showing comparability ( P>0.05). Follow-ups revealed grade A wound healing in all patients. There were no significant differences between the 2 groups in time for planning screw removal path, fluoroscopy frequency, fluoroscopy time or operation time ( P>0.05). The anesthesia time [(41.6 ± 8.3) min], anesthesia cost [(653.5 ± 102.6) yuan] and postoperative ambulation time [(2.6 ± 0.6) h] in the LA group were significantly less than those in the GA group [(52.3 ± 9.5) min, (2,475.6 ± 261.8) yuan and (8.7 ± 2.4) h] while the VAS score in the former group (3.8 ± 1.5) was significantly higher than that in the latter group (2.5 ± 1.3) (all P<0.05). Conclusions:It is feasible to use local anesthesia for TiRobot-assisted removal of sacroiliac screws. In TiRobot-assisted removal of sacroiliac screws, compared with general anesthesia, local anesthesia may lead to shorter anesthesia time, lower anesthesia cast and shorter ambulation time, but the patients need to be compliant enough.

Objective: To map OTA/AO type B and type C distal radial fractures according to three-dimensional (3D) CT scan data, and to describe the morphological distribution of fracture lines. Methods: A total of 468 cases of distal radius fractures admitted to the Affiliated Hospital of Chengdu University from January 2016 to March 2019 were analyzed and AO classification were performed. AO type B and type C fractures meet the inclusion criteria and then CT data were 3D reconstructed, and morphological description were performed on the fracture lines of each joint surface, including fracture shape angle, fracture area and fracture ratio. At the same time, the articular surface fracture model was superimposed on the standard model, then fracture line and fracture area distribution map were drawn to create the fracture map of intra-articular distal radial fractures. Result: Intra-articular fractures of the distal radius were 209 cases, accounting for 44.7% (209/468) of the distal radius fractures, among which 67 cases of AO type B fracture. In type B fractures, average fracture height were 20.30±11.26 mm, average fracture width were 12.24±6.83 mm, average fracture area were 189.61±101.84 mm², average angle were 57.23°±14.95°, and average area ratio of fracture (fracture zone area/joint surface area ratio) were 32.42%±10.24%. 142 cases were OA type C fracture, the average fracture height were 24.43±11.37 mm, average fracture width were 20.38±7.59 mm, average fracture area were 425.26±314.31 mm², average angle were 51.26°±13.17°, and average area ratio of fracture were 73.81%±26.29%. According to fracture map formed by main fracture lines, five different fracture areas were identified: ① 63 cases in central area; ② 25 cases in Lister's nodule area; ③ 59 cases in scaphoid area; ④ 36 cases in lumbar fossa area; ⑤ 26 cases in lower iliac area. Main fracture lines were concentrated in the area on the dorsal side of the central area and the scaphoid area. The fracture lines of type B fracture mainly concentrated in scaphoid region, which accounted for 29.85% (20/67), and dorsal side and central area accounted for 26.87% (18/67). The fracture lines of type C fracture accounted for 27.46% (39/142) in scaphoid area and 31.69% (45/142) in central area. The fracture line of type C fracture increased in the lumbar fossa region (17.61%, 25/142) and the lower ulnar region (12.68%, 18/142) compared with type B fracture (28.69%). Compared with the type B fracture, the overall distribution of the fracture line of the type C fracture is more central. Conclusion The map of intra-articular fracture of distal radius was drawn and morphological distribution of fracture lines were quantified. Fracture-prone site and shape of fracture line were visually recognized. At the same time, description of articular surface fracture line and fracture area of type B and type C fractures of OA classification were improved, which may help with new classification and diagnosis.