ObjectiveTo investigate the effectiveness of TiRobot-assisted percutaneous sacroiliac cannulated screw fixation in the treatment of posterior pelvic ring injuries with sacral variations, and to evaluate its feasibility and safety. Methods The clinical data of 7 patients with Tile type C pelvic fractures and sacral variations treated with TiRobot-assisted percutaneous sacroiliac cannulated screw fixation between January 2020 and June 2021 were retrospectively analyzed. There were 5 males and 2 females with an average age of 36 years (range, 17-56 years). The causes of injury were traffic accident in 4 cases and falling from height in 3 cases. According to Tile classification of pelvic fractures, there were 1 case of type C1.1, 1 case of type C1.2, and 5 cases of type C1.3; according to Denis classification of sacral fractures, there were 3 cases of zone Ⅰ and 4 cases of zone Ⅱ; sacral deformities included 3 cases of lumbar sacralization, 2 cases of sacral lumbarization, and 2 cases of accessory auricular surface of the sacrum. The time from injury to operation ranged from 2 to 7 days, with an average of 4.6 days. The implantation time of each screw, the fluoroscopy times of each guide pin, the quality of fracture reduction (according to Matta score), the excellent and good rate of screw position, the healing time of fracture, and the incidence of complications were recorded, and the effectiveness was evaluated by Majeed score. Results A total of 13 screws were implanted during the operation, the implantation time of each screw was 10-23 minutes, with an average of 18.2 minutes; the position of the guide pin was good, and no guide pin was adjusted, the fluoroscopy times of each guide pin were 3-7 times, with a median of 4 times. Postoperative imaging data at 3 days showed that the position of sacroiliac screw implantation was evaluated as excellent. No complication such as incision infection or vascular nerve injury occurred, and no adverse events related to robotic devices occurred. At 3 days after operation, according to Matta score, the quality of fracture reduction was excellent in 6 cases and good in 1 case, and the excellent and good rate was 100%. All the 7 patients were followed up 6-15 months, with an average of 12.4 months. Bone union was achieved in all patients, and the healing time ranged from 18 to 24 weeks, with an average of 21.2 weeks. Majeed score at last follow-up was 81-95, with an average of 91.5; 5 cases were excellent, 2 cases were good, and the excellent and good rate was 100%. ConclusionTiRobot-assisted percutaneous sacroiliac cannulated screw fixation for posterior pelvic ring injury with sacral variation is accurate, safe, minimally invasive, and intelligent, and the effectiveness is satisfactory.
ObjectiveTo explore the value of the long time lower abdominal aorta balloon block technology in the pelvis or sacrum tumor surgery. MethodsFrom January 2005 to June 2013, the sacrum or pelvic tumor patients underwent the long time lower abdominal aorta balloon block technology in the Orthopedics Department of West China Hospital of Sichuan University were enrolled. According to the balloon blocking time, patients were divided into A (<90 mins), B (90 to 180 mins), and C (>180 mins) groups. The intraoperative blood loss, blood transfusion amount, average lengths of hospital stay, postoperative volume of drainage, and postoperative complications were compared among the three groups. ResultsA total of 78 patients were included, of which 21 were in group A, 38 were in group B and 19 were in group C. All patients received en bloc resection, and did not experience intraoperative balloon shift and abdominal aorta flow leakage. Comparing the three groups, there were significant differences in intraoperative blood loss (P=0.026) and average lengths of hospital stay (P=0.021). Further pairwise comparison showed the intraoperative blood loss and average lengths of hospital stay in group C were significantly higher than those in group A and group B. In addition, there were no statistical differences among the three groups in blood transfusion amount, postoperative volume of drainage and postoperative complications. ConclusionIn the pelvis and sacrum tumor surgery, extending the time of abdominal aorta balloon block can reduce bleeding, save blood, increase the safety of surgery without increasing in postoperative complications.
Objective To study the MRI diagnosis of sacral fracture with sacral neurological damage and its cl inical appl ication. Methods From October 1999 to October 2007, 20 cases of sacral fracture (Denis classification, Type II)with sacral neurological damage were examined by obl ique coronal MRI of sacrum to show the whole length of sacral nerve. There were 17 males and 3 females, aged 30-55 years. The time from injury to hospital ization varied from 1 day to 23 months. The injury was caused by traffic accident in 10 cases, smash of heavy object in 8 cases and crush in 2 cases. Eight cases were accompanied by pubis fracture and 4 cases by urethral disruption. All patients accepted the examination of X-ray, CT and spiral CT 3D reconstruction. X-ray showed the displacement of fracture fragment was backwards and upwards, and sacral-hole l ine was vague, asymmetric and distorted. CT showed that sacral neural tube was left-right asymmetry, the displacement of fracture fragment was backwards and upwards, combining with the compression and intruding to sacrum center at different section levels. The cl inical manifestations, international standards for Neurological Classification of Spinal Cord Injury recommended by American Spinal Injury Association International Spinal Cord Society, comparison between normal and abnormal MRI and Gierada’s results were the basis for cl inical diagnose and MRI diagnose, which was confirmed by operation. Results Nerve injury diagnosed by cl inical manifestation were S1 (17 cases), S2 (14 cases), S3 (7 cases), and S4 (6 cases). Nerve injury diagnosedby MRI were S1 (17 cases), S2 (14 cases), S3 (3 cases), and S4 (2 cases). Nerve injury confirmed by operation were S1 (17 cases), S2 (14 cases), S3 (7 cases), and S4 (1 case). Obl ique coronal MRI of sacrum showed the whole length of sacral nerve and its adjacent relationship, detecting bone fragment compression and route alteration of never were evident in 5 cases, the fat disappearance around the site of nerve root injury in 19 cases, narrowness of sacral nerve canal in 17 cases and the abnormally enlarged sacral nerve in 11 cases. Conclusion Obl ique coronal MRI of sacrum is of great value in the local ization and the qual itative diagnosis of sacral neurological damage.
ObjectiveTo study the value of CT angiography (CTA) in the surgical treatment of bone tumors with the temporary balloon blocking technique. MethodsA retrospective analysis was made on the clinical data of 36 bone tumor patients between April 2008 and October 2013. There were 22 males and 14 females, aged from 25 to 83 years (mean, 46 years). The tumor located at the sacrococcygeal region in 17 cases, at the ilium in 12 cases, at the pubis in 5 cases, and at the proximal femur in 2 cases. Before surgery, CTA was performed to measure the external diameter of aortaventralis and arteria iliac communis, and the distance between the low renal artery and the abdominal aortic bifurcation as well as mark the anatomical relationship between the low renal artery, the abdominal aortic bifurcation and bony landmarks of vertebral body. According to these data, suitable balloon was chosen and the balloon positioning was guided in the surgery to completely excise tumor assisted by balloon blocking technique. ResultsThe CTA results showed that the external diameter of aortaventralis and arteria iliaca communis was (1.545±0.248) cm and (1.060±0.205) cm respectively, and the distance between the low renal artery and the abdominal aortic bifurcation was (10.818±1.165) cm. The three-dimensional reconstruction showed that the opening of the low renal artery was mainly located at L1 (16/36, 44.4%) and the abdominal aortic bifurcation mainly located at L4 (22/36, 61.1%). Effective block of abdomial aorta was performed; the blood pressure obviously increased in 3 cases after balloon inflation, and pulse of the left dorsal artery of the foot decreased in 1 case after removal of balloon, which were relieved after expectant treatment. The operation time was 118-311 minutes; the intraoperative blood loss was 200-1 800 mL, 21 patients were given blood transfusion, and the amount of blood transfusion was 400-1200 mL; and the aortic clamping time was 40-136 minutes. All patients were followed up 5-44 months (mean, 21 months). According to Enneking standard, the results were excellent in 9 cases, good in 20 cases, fair in 5 cases, and poor in 2 cases at 3 months after operation. There were 10 cases of dysfunction of urination and defecation, 2 cases of tumor recurrence, and 3 cases of death after surgery. ConclusionCTA and three-dimensional reconstructions technique can accurately measure the external diameter of aortaventralis and arteria iliaca communis and the distance between low renal artery and abdominal aortic bifurcation and offer great help to choose appropriate balloon and locate the balloon during surgery. The balloon blocking technique under the assistance of CTA can obviously reduce intraoperative blood loss and tumor recurrence, supply a clear view in surgery and shorten the operation time.
ObjectiveTo evaluate the clinical efficiency of balloon occlusion of the lower abdominal aorta in blood loss control during resections of pelvic or sacral tumor. MethodsFrom April 2006 to April 2010, 24 patients diagnosed as pelvic or sacral tumor in this hospital were collected. Balloon occlusion of the lower abdominal aorta to control blood loss was used in these cases. Balloon catheters were placed via femoral artery to occlude the abdominal aorta before operation. Resections of pelvic or sacral tumors were performed after occlusion of abdominal aorta, duration no longer than 60 min per occlusion, if repeated occlusions needed, 10－15 min release in between. Results Average operative time was 153 min (range 40－245 min) and average blood loss was 310 ml (range 200－650 ml) in this series, and the procedure helped in clearly identifying the surgical margin, neurovascular structures, and adjacent organs. The blood pressure were stable in all the cases. No postoperative renal function impairment was found in all the cases, no side injuries to adjacent organs was identified. One case complicated with thrombosis in iliac artery at same puncture side was successfully treated with catheter thrombectomy. ConclusionIntraoperative abdominal aorta balloon occluding in pelvic and sacral tumor surgical operation could reduce blood loss, and improve the safety of operation.
To evaluate the cl inical effect of pedical screw systems fixed between lumbar and il ium for treatment of sacral fractures. Methods From June 2003 to June 2009, 21 cases of sacral fracture (29 sides including monolateral 13 cases and bilateral 8 cases) were treated with pedical screw systems to have reduction and fixation. There were 12 males and 9 females, aging 23-59 years (38.2 years on average). Fractue was caused by traffic accident in 12 cases, by fall ingfrom height in 7 cases, and by crash in 2 cases. Screws were inserted into lumbar pedicles and il iac crests. Decompression was used in 4 cases compl icated by sacral nerves injury, and reductions and fixations were used in 12 cases compl icated anterior pelvic or acetabulum injury. The preoperative proximal displacement at the injured side of the pelvis was (16.29 ± 6.47) mm compared with contralateral pelvis. Results All incisions healed primarily with no compl ication of infection. Twentyone patients were followed up 6 months to 6 years. Cl inical heal ing time of fracture was 6-9 weeks. In 4 cases compl icated by S1 or S2,3 nerves injury, the function recovered completely after 4-9 weeks. In other 17 patients, no compl ication of intraoperative nerve injury occurred. All patients could walk and squat after 6-12 weeks of operation. No breakage or displacement of implant occurred. The postoperative proximal displacement at the injured side of the pelvis was (3.51 ± 0.68) mm compared with contralateral pelvis, showing significant difference (P lt; 0.01) when compared with preoperative one. Conclusion It is a novel choice to have reduction and internal fixation for sacral fracture with pedical screw systems fixed between lumbar and il ium. The strict regulation of indication and skill is the key to prevent compl ication.
Objective To biomechanically compare the maximum pull-out strengths among two pedicle screws and three salvage techniques using poly methylmethacrylate (PMMA) augmentation in osteoporotic sacrum, and to determine which PMMA augmentation technique could serve as the salvage fixation for loosening sacral pedicle screws. Methods Eleven sacra were harvested from fresh adult donated cadavers, aged from 66 to 83 years (average 74.4 years) and included 5 men and 6 women. Radiography was used to exclude sacra that showed tumor or inflammatory or any other anatomic abnormal ities. Following the measurement of bone mineral density, five sacral screw fixations were sequentially establ ished on the same sacrum as follows: unicortical pedicle screw (group A), bicortical pedicle screw (group B), unicortical pedicle screw with the traditional PMMA augmentation (group C), ala screw with the traditional PMMA augmentation (group D), and ala screw with a kyphoplasty-assisted PMMA augmentation technique (group E). According to the sequence above, the axial pull-out test of each screw was conducted on a MTS-858 material testing machine. The maximum pull-out forces were measured and compared. The morphologies of PMMA augmented screws after being pulled-out were also inspected. Results The average bone mineral density of 11 osteoporotic specimens was (0.71 ± 0.08) g/cm2 . By observation of the pull-out screws, groups C, D, E showed perfect bonding with PMMA, and group E bonded more PMMA than groups C and D. The maximum pull-out forces of groups A, B, C, D, and E were (508 ± 128), (685 ± 126), (846 ± 230), (543 ± 121), and (702 ± 144) N, respectively. The maximum pull-out strength was significantly higher in groups B, C, and E than in groups A and D (P lt; 0.05), and in group C than in groups B and E (P lt; 0.05). There was no significant difference in pull-out strength between groups A and D, and between groups B and E (P gt; 0.05). Conclusion For sacral screw fixation of osteoporotic patients with bone mineral density more than 0.7 g/cm2, bicortical pedicle screw could acquire significantly higher fixation strength than the unicortical. Once the loosening of pedicle screw occurs, the traditional PMMA augmentation or ala screw with kyphoplasty-assisted PMMA augmentation may serve as a suitable salvage technique.
ObjectiveTo investigate the clinical efficiency of pelvic and sacrum tumor surgery using sizing balloon occlusion of the lower abdominal aorta. MethodsFrom January 2005 to June 2011, 156 patients were diagnosed to have sacrum or pelvic tumor and underwent surgery in our institution. Temporary balloon occlusion of abdominal aorta was used in 51 patients during the resection of sacrum and pelvic tumors (balloon group). Another 105 patients received the traditional surgery resection (control group). The results of the whole operation time, the volume of blood loss and transfusion, the complication and the total days of stay in hospital in the two groups were compared with each other. ResultsAfter the abdominal aorta was occluded, 92.2% of the patients in the balloon group had holistic resection or edge resection, while the number was 86.7% for the control group. In the balloon group, the average operation time was (171.96±65.16) minutes, the average intraoperative blood loss was (746.86±722.73) mL, and the blood transfusion was (411.76±613.73) mL. The postoperative lead flow was (294.50±146.09) mL, and the postoperative tube removal was within (2.98±1.07) days. Improvement of patients'condition was significantly better than the control group (P<0.05). No significant difference was found in the total days of stay in hospital and the postoperative complications between the two groups (P>0.05). ConclusionUsing abdominal aorta occlusion can effectively control intraoperative hemorrhage, and show the operation field clearly. It also can reduce operation time and control the blood transfusions. Appropriately extended balloon blocking time can obviously improve the tumor removal rate and the safety of the operation.