Objective:To investigate the efficacy of opening wedge high tibial osteotomy (OWHTO) in the treatment of knee osteoarthritis, and analyze the related factors that affect its clinical efficacy.Methods:The clinical data of 80 patients with knee osteoarthritis who underwent OWHTO between December 2016 and May 2020 in Hospital of the Marine Police Corps of the Chinese People's Armed Police Force were retrospectively analyzed. These patients were divided into effective group ( n = 76) and ineffective group ( n = 4) according to clinical efficacy. The Visual Analogue Scale (VAS), the Hospital for Special Surgery Knee Score (HSS) and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) were used to assess the severity of knee osteoarthritis before and 3 months after surgery. The influential factors of clinical efficacy were analyzed. Results:VAS score, WOMAC score, HSS score, joint pain, joint function, joint range of motion, muscle strength, and flexion deformity of 80 patients post-surgery were improved compared with those pre-surgery ( t = 24.92, 21.45, 52.62, 15.87, 10.88, 15.28, 42.54, 11.07, all P < 0.05). After surgery, excellent outcomes were observed in 29 (36.25%) patients, good outcomes in 34 (42.50%) patients, fair outcomes in 13 (16.25%) patients, and poor outcomes in 4 (5.00%) patients. Body mass index, preoperative VAS score, and preoperative WOMAC score in the effective group were (24.10 ± 3.06) kg/m 2, (5.55 ± 1.57) points, and (36.96 ± 9.62) points, respectively, which were significantly lower than those in the ineffective group [(27.64 ± 3.62) kg/m 2, (7.87 ± 1.39) points, (47.95 ± 9.63) points, t = 2.23, 2.89, 2.22]. HSS score in the effective group was significantly higher than that in the ineffective group [(52.81 ± 3.71) points vs. (46.83 ± 3.69) points, t = 3.14, P < 0.05)]. Body mass index, preoperative VAS score, and preoperative WOMAC score were positively correlated with clinical efficacy ( r = 0.24, 0.31, 0.24, P < 0.05), and preoperative HSS score was negatively correlated with clinical efficacy ( r = -0.33, P < 0.05). Logistic regression analysis was performed to analyze the above markedly related factors. Preoperative HSS score was an independent protective factor of clinical efficacy of OWHTO, and body mass index and preoperative VAS score were risk factors of clinical efficacy of OWHTO. Conclusion:OWHTO can greatly improve knee function of patients with knee osteoarthritis and reduce postoperative pain. It should be noted that excessive obesity may affect the clinical efficacy of OWHTO, and preoperative VAS score and WOMAC score should be controlled in patients with excessive obesity.

Objective:To explore the feasibility and clinical efficacy of oblique lateral interbody fusion (OLIF) in the treatment of adjacent segment disease (ASDis).Methods:Retrospective analysis was conducted on the data of 31 patients with ASDis treated by OLIF in four medical centers from June 2015 to December 2018. There were 17 males and 14 females. The average age was (65.7±3.4) years (range, 59 to 75 years). 19 cases received single-segment fixed fusion, 11 cases received double-segment fixed fusion and 1 case received three-segment fixed fusion. Original fixed fusion site: 1 case of L 1, 2, 3 cases of L 3, 4, 11 cases of L 4, 5, 4 cases of L 5S 1, 6 cases of L 3-L 5, 5 cases of L 4-S 1, and 1 case of L 3-S 1. The time from the initial fixation and fusion to this admission was 82.5±45.5 months (rang, 24 to 180 months). ASDis occurred at the proximal end of the fixed fusion segment in 28 cases and at the distal end in 3 cases. The types of ASDis: degenerative disc disease in 11 cases, lumbar spinal stenosis in 15 cases, degenerative spondylolisthesis in 2 cases, and degenerative scoliosis in 3 cases. The location of ASDis: 6 cases of L 2, 3, 12 cases of L 3, 4, 6 cases of L 4, 5, 3 cases of L 1-L 3, 1 case of L 2-L 4, and 3 cases of L 1-L 4. At admission, 3 cases of lumbar internal fixation had been removed and 28 cases of internal fixation remained. Stand-alone OLIF was performed in 19 cases, OLIF combined with pedicle screw fixation in 8 cases, and OLIF combined with cortical screw fixation in 4 cases. Visual analogue scale (VAS) and Oswestry disability index (ODI) were used to evaluate the low back pain and lumbar function before operation and at the last follow-up, and the imaging results and complications were observed. Results:All patients were followed up. The follow-up time was 23.6±9.6 months (range, 12 to 60 months). The operation time was 73.8±25.3 mins (range, 40 to 180 min), and the intraoperative blood loss was 86.2±67.4 ml (range, 20 to 310 ml). The average blood loss in each segment was 24.8 ml. During the operation, there were 1 case of segmental vein injury, 7 cases of endplate injury, 2 cases of transient iliopsoas muscle weakness, 1 case of thigh pain and numbness, and 1 case of incomplete intestinal obstruction. There was no incision necrosis and infection. The VAS score of low back pain decreased from 5.9±1.9 before operation to 1.4±0.6 at the last follow-up, with a statistically significant difference ( t=8.47, P<0.001). The ODI index recovered from 45.2%±5.7% before operation to 13.8%±4.7% at the last follow-up, with a statistically significant difference ( t=7.92, P<0.001). The height of intervertebral space increased from 8.7±1.6 mm before operation to 11.4±1.9 mm after operation and 9.9±1.8 mm at the last follow-up. There was a statistically significant difference between postoperative and preoperative height of intervertebral space ( F=4.15, P=0.007). There was a statistically significant difference between the last follow-up and postoperative height of intervertebral space ( P=0.011). During the follow-up, there were 13 cases of fusion cage subsidence, 1 case of fusion cage displacement, and no case of internal fixation loosening or fracture. The intervertebral fusion rate was 94%(29/31) and the complication rate was 42%(13/31). Conclusion:ASDis is a common complication after lumbar fixation and fusion, and requires surgical treatment. OLIF is a reliable method to treat ASDis as it has advantages of small trauma, high fusion rate and low complication rate.

There are many vague understandings or misunderstandings in diagnosis, treatment concept and treatment methods of osteoporotic thoracolumbar fractures. For the treatment of osteoporotic thoracolumbar fractures, the first step is to grasp the core pathological basis and conduct necessary examinations. The choice of treatment should be made individually based on the injury severity, age, bone conditions, injury locations, injury types and combined injuries, so as to ensure surgery safety and reduce complications. Meanwhile, the postoperative function improvement of patients'also needs to be cared. The author analyzes the common misunderstandings in diagnosis and treatment of osteoporotic thoracolumbar fractures and proposes improvements to provide reference for clinical treatment.

Objective:To compare the clinical outcomes and complications of oblique lateral interbody fusion combined with bilateral pedicle screw fixation through intermuscular approach and posterior interbody fusion combined with bilateral pedicle screw fixation through intermuscular approach by channel for lumbar spinal stenosis.Methods:A retrospective study was conducted on 73 patients who underwent surgical treatment for lumbar spinal stenosis from Jun 2015 to Jun 2017, including 33 males and 40 females. The average age was 66.8±7.94 years (from 39-85 years). These diseases occured at L 3/4 in 5 patients and L 4/5 in 68 patients. Random according to the time of admission, 38 cases were treated with oblique lateral interbody fusion combined with bilateral pedicle screw fixation through intermuscular approach (oblique lateral fusion group), and 35 cases with posterior interbody fusion combined with bilateral pedicle screw fixation through intermuscular approach by channel (posterior fusion group). The clinical results, image data and complications were compared between the two groups. Results:All patients in both groups had operation performed smoothly. The operation time was 99±8.96 min in the oblique lateral fusion group and 96.8±9.57 min in the posterior fusion group, and there was no significant difference between the two groups. The intraoperative bleeding in the oblique lateral fusion group 80±24.72 ml was significantly less than that in the posterior fusion group 261±52.87 ml ( t=9.621, P<0.05). No incision infection occurred after surgery. The VAS score of lumbar incision 72h after operation in the oblique lateral fusion group 1.21±0.55 was significantly less than that in the posterior fusion group 1.70±0.86 ( t=3.723, P=0.028). The follow-up period lasted for 12-24 months, averagely 17.5±2.58 months. There was statistically significant difference between preoperative and postoperative in the two groups, whether it was the area of the foraminal canal or the area of the spinal canal. There wboth the foraminal area and the spinal canal area were enlarged. The intervertebral space height in the two groups recovered significantly after surgery, the difference was statistically significant. But the intervertebral space height were partly lost at the last follow-up, and there was significant difference compared with postoperative. During the follow-up, no pedicle screw loosening, displacement, rupture, or anterior and lateral displacement of cage occurred. The fusion rate was 97.1% in the posterior fusion group and 100% in the oblique lateral fusion group. There was no statistical difference between the two groups.In terms of ODI index: the posterior fusion group recovered from 48.6±6.1 preoperative to 10.2±2.2 at the last follow-up, and the oblique lateral fusion group recovered from 49.0±5.7 preoperative to 9.3±1.8 at the last follow-up. There was statistically difference between last follow-up and preoperative in the two groups. The incidence of complications in the posterior fusion group was 22.86%, and the incidence in the oblique lateral fusion group was 23.68%. There was no significant difference between the two groups. Conclusion:Both the two decompression and fusion methods have achieved good clinical results in the treatment of lumbar spinal stenosis, with the advantages of less trauma, good stability, fast recovery, and high fusion rate. Compared with posterior decompression and fusion methods, the advantages of OLIF are more obvious, such as less bleeding,lower risk of nerve injury and good indirect decompression of spinal canal. Therefore, the OLIF technique can be a better choice for surgical treatment of lumbar spinal stenosis.

Objective:To investigate the characteristics and causes of endplate injury in the oblique lateral interbody fusion for the treatment of lumbar diseases, and summarize the precaution of endplate injury.Methods:Thirty-five cases of endplate injury were observed, which were originally treated with oblique lateral interbody fusion with or without pedicle screw fixation from October 2014 to December 2017. There were 7 males and 28 females, and the age ranged from 51 to 78 years old (averagely 62.8±8.13 years). There were 2 cases of lumbar disc degeneration, 10 cases of lumbar canal stenosis, 17 cases of lumbar degenerative spondylolisthesis, 2 cases of lumbar spondylolysis with or without spondylolisthesis, and 4 cases of lumbar degenerative scoliosis. Lesion sites contained L 3,4 in 2 cases, L 4,5 in 21 cases, L 2-4 in 3 cases, L 3-5 in 4 cases, L 2-5 in 3 cases and L 1-5 in 2 cases. Preoperative bone mineral density examination revealed there were 7 cases of T>-1 SD, 24 cases of -2.5 SD

Objective To investigate the feasibility and effectiveness of bilateral pedicle screw fixation combined with in-terbody fusion for the treatment of lumbar spondylolisthesis (degree Ⅱ or Ⅲ) through muscle-splitting approach. Methods There were 52 patients (16 males and 36 females) analyzed in our study from January 2012 to December 2015. The average age was 54.9 ± 7.21 years (from 35 to 70 years). The history of disease was from 10 months to 15 years, with an average of 66.6 ± 32.71 months. Diagnosis included:degenerative spondylolisthesis in 2 cases, and isthmic spondylolysis in 50 cases. The sites included L4,5 in 18 cases and L5S1 in 34 cases. The degree was Ⅱ in 35 cases and Ⅲ in 17 cases. 27 cases were treated by bilateral pedicle screw fixation combined with interbody fusion through median incision approach (open group) and 25 cases through muscle-split-ting approach (minimally invasive group). The clinical and imaging results were observed and compared between the two groups, including operation time, intraoperative blood loss, postoperative incision drainage, VAS score of lumbar incision pain at 72h post-operative, intraoperative and postoperative complications, interbody fusion rate, multifidus muscle areas and grades at 1 year post-operative, and the improvement of ODI index. Results All the cases were operated successfully. The operation time of open group was shorter than minimally invasive group. However, the intraoperative blood loss and postoperative incision drainage of minimally invasive group was statistically less than open group. The VAS scores of postoperative 72 h were 3.25 (2 to 6) in open group and 1.62 (1 to 3) in minimally invasive group. And the difference was statistically significant. The misplacement rate of pedi-cle screws of minimally invasive group was lower than open group. The average follow-up time was 25.5 months (ranged from 12 to 36 months). The multifidus muscle areas and grades of minimally invasive group were superior to open group at 1 year postopera-tively. Compared to preoperative, the slipping angle, slipping rate, sacral inclination angle and vertebral space height were signifi-cant improved after operation in two groups. The ODI index was improved postoperatively in both two groups, and the difference was statistically significant at the final follow-up. The interbody fusion rate was 92.6％in open group and 96％in minimally inva-sive group, and there was no significant difference between the two groups. No cerebrospinal fluid leak, never injury, pedicle frac-ture or wound infection was found after the operation in two groups. There was no pedicle screw loosening, cage shifting, or degen-eration of the adjacent segment observed during follow-up. Conclusion Bilateral pedicle screw fixation combined with inter-body fusion through muscle-splitting approach has advantages of small incision, less trauma, less bleeding, quick recovery and well clinical results, which can be a better choice in treating lumbar spondylolisthesis (degree Ⅱ or Ⅲ).

Objective To evaluate the effectiveness and radiographic outcomes of percutaneous kyphoplasty (PKP)/percutaneous vertebroplasty (PKP) in the treatment of stage Ⅲ Kümmell's disease without nerve injury.Methods From September 2012 to September 2016,there were 28 patients with stage Ⅲ Kümmell's disease recruited to study,of which 16 patients were treated with PKP and the other 12 cases with PVP.with a mean age of 78,ranging from 67 to 95,consisted of 3 males and 29 females.All patients had single vertebral body lesions without symptom of spinal cord injury.Visual analogue scores (VAS) and oswestry dysfunction index (ODI) were recorded before surgery,on the 7 d after surgery and at the last follow-up.Meanwhile,Cobb angles,anterior and posterior heights of the injured vertebral body were measured by X-ray lateral radiography at these three time points.Furthermore,the condition of bone cement in the injured vertebral body was observed with the postoperative CT examination.Results All patients completed the operation safely.Twenty-eight patients were followed up for an average of 18 months (ranging from 12 to 36 months),and 4 patients who failed to be followed up were not included in the statistic analysis.There was no vessel or nerve injury in the operation.Thirteen out of 28 individuals who suffered from bone cement leakage showed no clinical symptom,and recovered walking ability between 12 and 24h after operation.Other types of vertebral body fractures due to compression occurred in 3 cases between 6 and 12 months after surgery,and the symptoms were relieved after another PKP.The rates of improvement at the last follow-up in VAS and ODI were 71.4％ (20/28) and 67.9％ (19/28),respectively.There was statistical difference in VAS between before surgery and 7d after surgery (t=16.68,P＜0.01).However,no statistical difference was found in the comparison of VAS between the last follow-up and 7d after surgery (t=0.598,P ＞ 0.05).The difference of ODI between before surgery and 7d after surgery (t=36.830,P＜0.01) and that of ODI between the last follow-up and 7d after surgery (t=7.375,P＜0.01) showed statistical significance.There were statistical differences in both Cobb angle and anterior heights of the diseased vertebral body between before surgery and 7d after surgery (t=2.52,2.29,both P＜0.05).Besides,significant differences were also observed in them between the last follow-up and 7d after surgery (t=2.58,2.24,both P＜0.05).However,there was no statistical difference of the posterior height of the diseased vertebral body before surgery,7d after surgery and at the last follow-up (t=0.935,0.795,P＞0.05).Conclusions PKP/PVP may relieve the clinical symptoms safely and effectively of stage Ⅲ Kümmell's disease without nerve injury,and may correct heights of kyphosis and vertebral.Nevertheless,it may lead to loss of correction and high rate of bone cement leakage.Further observation is needed for the long-term effectiveness.

Objective To examine the feasibility and early effects of unilateral pedicle screw fixation in combination with contralateral translaminar facet screw fixation plus interbody fusion through the channel-assisted muscle-splitting approach for the treatment of degenerative lumbar spine diseases in elderly patients.Methods A total of 82 elderly patients with degenerative lumbar spine diseases received treatment between January 2015 and June 2016.Of these patients,25 had lumbar spinal stenosis,42 had degenerative lumbar instability,13 had giant lumbar disc herniation,and two had recurrent lumbar disc herniation;There were 69 cases of single segment and 13 cases of double segment lesions.Perioperative evaluation,imaging evaluation,and clinical evaluation were performed,and surgical complications were analyzed.Results The average length of incision was (2.6 ± 0.4) cm in cases of single segment lesions and (4.4±0.5) cm in cases of two segment lesions.The mean operation time was (98.3±19.6) minutes and peri-operation blood loss was (232.2±25.8) ml.The post-operation height of the intervertebral disc space significantly increased at the last follow-up(P ＜ 0.05);the height of the intervertebral disc space was restored and well maintained with internal fixation showing no loosening,breakage or Cage shift.The post-operation lumbar coronal Cobb angle decreased(P＜0.05)while the sagittal Cobb angle increased(P＜0.05)at the last follow-up.There was no significant difference in the area and grade of the multifidus muscle on MRI 12 months after operation.Seventy-two patients were followed up for 12-18 months (mean =16.8 months),and there were 67 cases of intervertebral fusion (93.1％).The last follow-up showed a Japanese Orthopaedic Association(JOA) score of (25.8 ± 1.7),which was significantly higher than the pre-operation score (10.6±1.3),with an excellence rate of 88.9 ％.The Oswestry Disability Index score was significantly reduced,from (50.9±21.6) at pre-operation to (9.6± 4.8) at the last follow-up.There were 78 patients with primary wound healing,three cases of superficial wound necrosis,one case of dural tear,and one case of nerve root injury.No cardiovascular or cerebrovascular incident was observed during or after operation.Conclusions Combined pedicle/facet screw fixation plus interbody fusion through the channel-assisted muscle-splitting approach shows satisfactory short-term effects when used for the treatment of degenerative lumbar spine diseases in the elderly and possesses advantages such as minimal invasiveness,limited bleeding,quick recovery,high fusion rates and significantly improved clinical outcomes.However,further clinical studies are required to assess its medium-and long-term efficacy.

Objective To compare the advantages and disadvantages of three different fixation methods via muscle-splitting approach for the treatment of single segmental lumbar vertebral diseases.Methods All of 90 patients with the single segmental lumbar vertebral diseases were treated from June 2012 to June 2013,including 34 males and 56 females,at the age of 27-76 years old,averagely (53.37± 15.41) years.Twenty-seven patients were treated with unilateral pedicle screws via unilateral muscle-splitting approach (unilateral fixation group).Thirty-three patients were treated with unilateral pedicle screws and contralateral translaminar facet screw via unilateral muscle-splitting approach (combined fixation group).Thirty patients were treated with unilateral pedicle screws via bilateral muscle-splitting approach (bilateral fixation group).Observe and compare the imaging and clinical results of these three groups.Results There were no significant difference in incision length and postoperative wound drainage between these three groups.The operation time was shortest in unilateral fixation group,while longest in bilateral fixation group.In the intraoperative blood loss,the unilateral fixation group was the same as the combined fixation group,while less than the bilateral fixation group.No infection was found after operations.Seven patients experienced epidermal necrosis of the incision,including 1 patient of unilateral fixation group,4 patients of combined fixation group and 2 patients of bilateral fixation group.Three patients suffered from nerve injury,including 2 patients of combined fixation group and 1 patients of bilateral fixation group.The follow-up time was from 12 to 36 months,averagely 25.5 months.The intervertebral height of lesion segments was apparently recovered after surgery,and maintained during the follow-up in these three groups.No significant changes of area and grade of multifidus muscle were detected at 1 year after surgery compared with preoperative.Seven patients experienced endplate cutting and cage partially embedded into vertebral body,including 3 patients of unilateral fixation group,3 patients of combined fixation group and 1 patient of bilateral fixation group.There was no loosening,displacement,breakage or cage shifting.Except 5 patients (2 patients of unilateral fixation group,2 patients of combined fixation group and 1 patient of bilateral fixation group),the remaining cases had well interbody fusion.At the final follow-up time,the JOA score significantly increased compared with preoperative.Besides,unilateral fixation group and combined fixation group were superior to bilateral fixation group.Conclusion Three different fixation methods via muscle-splitting approach for the treatment of single segmental lumbar vertebral diseases had well clinical results.The unilateral fixation and combined fixation via muscle-splitting approach had more advantages.The combined fixation via muscle-splitting approach is an innovation in approach,exposure and fixation aspects.

Objective To investigate the efficacy of modified 270°spinal canal decompression combined with one-stage pedicle screw fixation and vertebral reconstruction for severe thoracolumbar fractures.Methods A retrospective case-control study was made on 44 cases of severe thoracolumbar fractures treated from January 2009 to June 2014.There were 34 males and 10 females, with age range of 20-68 years (mean, 37.9 years).The injured vertebrae included T11/12 in one case, T12-L1 in 10, L1/2 in 21, L2/3 in nine and L3/4 in three.Injury type was all AO type B2.According to the American Spinal Injury Association (ASIA), neurological deficit was Grade A in three cases, Grade B in five, Grade C in 22, and Grade D in 14.Load sharing score (LSC) was 7-9 points (mean, 8.1 points), while the thoracolumbar injury classification and severity score (TLICS) was 7-9 points (mean, 8.2 points).According to the difference of surgical procedures, all cases were divided into traditional group (21 cases) and improved group (23 cases).The patients in traditional group were treated by 270° spinal canal decompression combined with one-stage pedicle screw fixation and vertebral reconstruction, and those in improved group were treated by modified 270°spinal canal decompression combined with one-stage pedicle screw fixation and vertebral reconstruction.Between-group differences were compared with regard to operation time, intraoperative blood loss, postoperative drainage, allogeneic blood transfusion, pain visual analogue scale (VAS) at postoperative 72 hours, Cobb angle, anterior vertebral height, spinal canal compromise, Denis score, work state, neurological function, bone graft fusion and complications.Results Duration of follow-up was (32.4±15.8)months (range, 12-60 months).No wound infection or deterioration of neurological function was found after operation.Operation time was (2.4±0.5)hours in traditional group, less than (2.8±0.6)hours in improved group (P<0.05), while there were no significant differences in intraoperative bleeding, postoperative draining and blood transfusion between the two groups (P>0.05).VAS was (3.2±0.9)points in traditional group and (3.3±0.9)points in improved group at postoperative 72 hours (P>0.05).Cobb angle, anterior vertebral height and spinal canal compromise in both groups obtained well recovery and maintained after operation (P<0.05), but the recovery of spinal canal compromise was better in improved group than traditional group [(2.1±1.8)% vs.(11.8±6.1)%] (P<0.05).Denis score and work state were similar between the two groups (P>0.05).At the last follow-up, ASIA Grade A was noted in three cases, Grade C in two, Grade D in 23, and Grade E in 16.Bone union was achieved in all cases, with no implant loosening or breakage observed.Thirteen cases in traditional group were found with residual bone fragments in the spinal canal after surgery, and two of them received revision surgery.Conclusions Either modified or traditional 270° spinal canal decompression combined with one-stage pedicle screw fixation and vertebral reconstruction can attain satisfactory clinical results in treatment of severe thoracolumbar fractures.However, the modified 270°spinal canal decompression can achieve more thorough decompression without reducing stability of the spine.