Objective To compare the effectiveness of O-arm navigation and C-arm navigation for guiding percutaneous long sacroiliac screws in treatment of Denis type Ⅱ sacral fractures. Methods A retrospective study was conducted on clinical data of the 46 patients with Denis type Ⅱ sacral fractures between April 2021 and October 2022. Among them, 19 patients underwent O-arm navigation assisted percutaneous long sacroiliac screw fixation (O-arm navigation group), and 27 patients underwent C-arm navigation assisted percutaneous long sacroiliac screw fixation (C-arm navigation group). There was no significant difference in gender, age, causes of injuries, Tile classification of pelvic fractures, combined injury, the interval from injury to operation between the two groups (P>0.05). The intraoperative preparation time, the placement time of each screw, the fluoroscopy time of each screw during placement, screw position accuracy, the quality of fracture reduction, and fracture healing time were recorded and compared, postoperative complications were observed. Pelvic function was evaluated by Majeed score at last follow-up. Results All operations were completed successfully, and all incisions healed by first intention. Compared to the C-arm navigation group, the O-arm navigation group had shorter intraoperative preparation time, placement time of each screw, and fluoroscopy time, with significant differences (P<0.05). There was no significant difference in screw position accuracy and the quality of fracture reduction (P>0.05). There was no nerve or vascular injury during screw placed in the two groups. All patients in both groups were followed up, with the follow-up time of 6-21 months (mean, 12.0 months). Imaging re-examination showed that both groups achieved bony healing, and there was no significant difference in fracture healing time between the two groups (P>0.05). During follow-up, there was no postoperative complications, such as screw loosening and breaking or loss of fracture reduction. At last follow-up, there was no significant difference in pelvic function between the two groups (P>0.05). Conclusion Compared with the C-arm navigation, the O-arm navigation assisted percutaneous long sacroiliac screws for the treatment of Denis typeⅡsacral fractures can significantly shorten the intraoperative preparation time, screw placement time, and fluoroscopy time, improve the accuracy of screw placement, and obtain clearer navigation images.
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.
Objective To observe the effect of selective sacral rhizotomy in treating spastic bladder after spinal cord injury and to explore the mechanism and the best surgical method of different sacral rhizotomies. Methods The spastic bladder models were established in 12 male dogsand were divided into 4 groups according to the different rhizotomies of the sacral nerve as the following: rhizotomy of the anterior root of S2(group A), rhizotomy of the anterior root of S2 and half of the anterior root of S3(group B), rhizotomy of the anterior roots of S2 and S3(group C), and total rhizotomy of the nerve roots of S2-4 (group D). By urodynamic examination and electrophysiological -observation, the changes of all functional data were recorded and comparedbetween pre-rhizotomy and post-rhizotomy to testify the best surgical method. In clinical trial, according to the results of the above experiments, rhizotomy of the anterior root of S2 or one of the halfanterior root of S3 were conducted on 32 patients with spastic bladder after spinal cord injury. The mean bladder capacity, the mean urine evacuation and the mean urethra pressure were (120±30), (100±30)ml and (120±20) cm H2 O, respectively before rhizotomy. Results After rhizotomy, the bladder capacity in 4 groups amounted to (150±50), (180±50), (230±50), and (400±50) ml, respectively; and the urine evacuation volume were (130±30), (180±50), (100±50) and (50±30)ml, respectively. In the treated 32 patients, the mean bladder capacity were raised to 410 ml, and the mean urine evacuation volume were also increased to 350 ml. Incontinence of urine disappeared in all patients. After 22-month follow-up on 13 patients, no recurrence was observed. Conclusion The effectof selective sacral rhizotomy in treating spastic cord injury is significant and worthy of further studies.
OBJECTIVE: To investigate an alternative procedure for complete denervation of bladder in the supra-cone cord injury to restore the bladder function. METHODS: Sixteen dogs were included in this study after their spinal cords were transected above the cone. They were divided into 6 groups and performed the rhizotomy of L7 to S3 root in different combination respectively. The bladder and urethra pressure change by electrostimulation during operation and cystometrogram change after operation were tested. RESULTS: 1. Electrostimulation study: for bladder innervation, S2was the most important and S1 was secondary. While for urethra innervation, S1 was more important than S2. When the anterior and posterior roots of S1 and S2 were intact with rhizotomy of posterior roots of L7 and S3, stimulated the common or posterior root of S1 and S2, the change of pressure in bladder and urethra was the same. When the anterior roots of S1 and S2 were resected with rhizotomy of posterior roots of L7 and S3, the pressure in bladder and urethra was significant decreased compared to stimulating the corresponding posterior roots. 2. Cystometrogram (CMG) study: in the complete deafferented group, resecting the posterior roots of L7 to S3, the bladder became flaccid. While resecting the posterior root of S2 and anterior root of S1 or, resecting the posterior root of S1 and anterior root of S2, combining with rhizotomy of posterior roots of L7 and S3, the CMG curve was similar to the complete deafferented group. In the S1 and S2 intact group, the bladder became spastic. CONCLUSION: Combining rhizotomy of anterior and posterior sacral root in different level has the same effects on bladder as complete deafferentation.
Objective To explore the method of the distal perforator-based gluteus maximus muscle V-Y flap to treat the sacral ulcer and to simplify the operative procedures.Methods From March 2002 to March 2005, 11 cases of sacral ulcer were repaired by distal perforatorbased gluteus maximus muscle flaps. The area of sacral ulcer ranged from 13 cm×11 cm to 18 cm×14 cm. Of 11 cases, 7 were female and 4 were male,whose age ranged from 21 to 69 years, and the disease course was 8 months to 3 years.A triangular flap was designed to create a V-Y advancement flap.The length of the base was made almost equal to the diameter of the defect.The apex of the tringle was located near the great trochanter. The medial part of the flap was elevated as a fasciocutaneous flap by dissecting the layer between the fascia and the muscle.The distal part ofthe flap was elevated by dissecting the layer between the gluteus maximus muscle and the fascia of the deeper muscle group.The flap was advanced to the defect. Results All the flaps survived. After a follow-up of 5 months to 3 years, the bilateral buttocks were symmetry and whose appearance was satisfactory. Except for 1 case dying of other disease, no recurrence of ulcer was observed.All the flaps survived. Conclusion The distal perforatorbased fasciocutaneous V-Y flap for treatment of sacral ulcers is a simple and reliable technique, which has several advantages over the conventional V-Y flap technique,such as excelent excursion,viable coverage with the fasciocutaneous component, high flap reliability, preservation of the contralateral buttock, and preservation of the gluteus maximus muscle function.
Objective To review the development of the reconstruction methods following total sacrectomy, and to provide reference for finding a better reconstruction method following total sacrectomy. Methods The case reports and biomechanical and finite element studies of reconstruction following total sacrectomy at home and abroad were searched. Development and current situation were summarized. Results After developing for nearly 30 years, great progress has been made in the reconstruction concept and fixation techniques. The fixation methods can be summarized as the following three strategies: spinopelvic fixation (SPF), posterior pelvic ring fixation (PPRF), and anterior spinal column fixation (ASCF). SPF has undergone technical progress from intrapelvic rod and hook constructs to pedicle and iliac screw-rod systems. PPRF and ASCF could improve the stability of the reconstruction system. Conclusion Reconstruction following total sacrectomy remains a challenge. Reconstruction combining SPF, PPRF, and ASCF is the developmental direction to achieve mechanical stability. How to gain biological fixation to improve the long-term stability is an urgent problem to be solved.
Objective To study the therapeutic effect of combining vacuum seal ing drainage (VSD) with gluteus maximus myocutaneous flap on the repair of soft tissue defect caused by the resection of sacral tumors. Methods From June2007 to June 2008, 6 patients with skin and soft tissue necrosis in the sacrococcygeal region, deep infection, and formation of cavity at 3-6 weeks after sacral tumors resection were treated. There were 4 males and 2 females aged 17-51 years old. The size of skin and soft tissue defects ranged from 15 cm × 11 cm × 6 cm to 20 cm × 18 cm × 7 cm. Every patient underwent VSD treatment for 7-10 days, and the recombinant bovine bFGF was injected into the wound intermittently for 7-14 days (250-300 U/ cm2 once, twice daily). The wound was repaired by either the gluteus maximus myocutaneous flap (5 cases) or the lumbar-gluteus flap (1 case), and those flaps were 9 cm × 9 cm-20 cm × 18 cm in size. The donor site were sutured or repaired with spl itthickness skin graft. Results All the flaps survived uneventfully. The wound healed by first intention in 5 cases, but 1 case suffered from fat l iquefaction 2 weeks after operation and healed after drainage and dressing change. All the donor sites healed by first intention, and all the skin grafts survived uneventfully. All the patients were followed up for 6-10 months, there was no relapse of sacral tumor, and the flaps showed no obvious swell ing with good color and elasticity. Conclusion With fewer compl ications, the combination of VSD and gluteus maximus myocutaneous flap is a safe and rel iable operative method for repairing the skin and soft tissue defects caused by the resection of sacral tumors.
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.
ObjectiveTo investigate the effectiveness of percutaneous double-segment lengthened sacroiliac screws internal fixation assisted by three-dimensional (3D) navigation technology in treatment of Denis type Ⅱ and Ⅲ sacral fractures. Methods A clinical data of 45 patients with the Denis type Ⅱ and Ⅲ sacral fractures admitted between January 2017 and May 2020 was retrospectively analyzed. There were 31 males and 14 females, with an average age of 48.3 years (range, 30-65 years). The pelvic fractures were all high energy injuries. According to the Tile classification standard, there were 24 cases of type C1, 16 cases of type C2, and 5 cases of type C3. The sacral fractures were classified as Denis type Ⅱ in 31 cases and type Ⅲ in 14 cases. The interval between injury and operation was 5-12 days (mean, 7.5 days). The lengthened sacroiliac screws were implanted in S1 and S2 segments respectively under the assistance of 3D navigation technology. The implantation time of each screw, the intraoperative X-ray exposure time, and the occurrence of surgical complications were recorded. After operation, the imaging reexamination was used to evaluate the screw position according to Gras standard and the reduction quality of sacral fractures according to Matta standard. At last follow-up, the pelvic function was scored with Majeed scoring standard. Results The 101 lengthened sacroiliac screws were implanted with the assisting of 3D navigation technology. The implantation time of each screw was 37.3 minutes on average (range, 30-45 minutes), and the X-ray exposure time was 46.2 seconds on average (range, 40-55 seconds). All patients had no neurovascular or organ injury. All incisions healed by first intention. The quality of fracture reduction was evaluated according to Matta standard as excellent in 22 cases, good in 18 cases, and fair in 5 cases, and the excellent and good rate was 88.89%. The screw position was evaluated according to Gras standard as excellent in 77 screws, good in 22 screws, and poor in 2 screws, and the excellent and good rate was 98.02%. All patients were followed up 12-24 months (mean, 14.6 months). All fractures healed and the healing time was 12-16 weeks (mean, 13.5 weeks). Pelvic function was evaluated according to Majeed scoring standard as excellent in 27 cases, good in 16 cases, fair in 2 cases, and the excellent and good rate was 95.56%. Conclusion Percutaneous double-segment lengthened sacroiliac screws internal fixation for the treatment of Denis type Ⅱ and Ⅲ sacral fractures is minimally invasive and effective. With the assistance of 3D navigation technology, the screw implantation is accurate and safe.