Objective To evaluate the effects of sacrectomy extent on the stabil ity of lumbo-il iac fixation using single or dual il iac screw technique, and to determine which conditions require the dual il iac screw technique. Methods Nine fresh L2 to pelvic specimens were harvested from donated adult cadavers. After testing the intact state simulated by L3-5 pedicle screw fixation, sequential partial sacrectomies and L3 to il iac fixation using bilateral single il iac screw (Single) wereconducted on the same specimen as follows: in group A, under S1 partial sacrectomy and Single; in group B, under 1/2 S1 partial sacrectomy and Single; in group C, one-side (left) sacroil iac joint resection and Single; in group D, total sacrectomy and Single; and in group E, the single il iac screw was replaced by dual il iac screws based on group D. Biomechanical testing was performed on a material testing machine under 0-800 N compression and —7-7 N•m torsion loading modes for construct stiffness evaluation. Results The compressive stiffness of intact condition was (392 ± 119) N/mm, groups A, B, C, D, and E obtained 106.4% ± 9.5%, 102.7% ± 8.0%, 92.2% ± 10.1%, 72.7% ± 8.0%, and 107.7% ± 10.7% of intact condition, respectively. No significant differences were found among groups A, B, C, and the intact state (P gt; 0.05), however, the four groups showed significantly higher compressive stiffness than group D (P lt; 0.05). Although group E exhibited a comparable compressive stiffness with groups A, B, and intact state (P gt; 0.05), it displayed markedly higher compressive stiffness than groups C and D (P lt; 0.05). The torsional stiffness of intact state was (3.22 ± 1.23) N•m/deg. Groups A, B, C, D, and E acquired 105.4% ± 10.1%, 89.8% ± 12.3%, 75.9% ± 10.6%, 71.2% ± 10.2%, and 109.1% ± 16.9% of intact state, respectively. No significant differences were detected among groups A, B, E, and the intact state (P gt; 0.05). However, groups C and D showed remarkably lower torsional stiffness than groups A, E, and the intact state (P lt; 0.05). Importantly, group E offered remarkably higher torsional stiffness than group B (P lt; 0.05). Conclusion After under 1/2 S1 partial sacrectomy, single il iac screw technique could effectively restore local stabil ity; whereas it could hardly provide adequate stabil ity for further resection of one-side sacroil iac joint or total sacrectomy; in such situation, the use of dual il iac screw technique could obtain sufficient construct stabil ity. Therefore, in the surgical treatment of sacral tumor, the dual il iac screw technique should be considered for the unstable conditions of totalsacrectomy or under 1/2 S1 sacrectomy with one-side sacroil iac joint resection.
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.
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 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.
To evaluate the appl ication value of internal fixation of spinal column by posterior approach and extraperitioneal bilateral focal debridement for the treatment of tuberculosis of lumbosacral vertebral body. Methods From March 2000 to February 2005, 16 cases of spinal tuberculosis in L3-S1 were treated with internal fixation of spinal column by posterior approach and extraperitioneal bilateral focal debridement. Sixteen cases included 11 males and 5 females, and the age was 21-56 years. The locations of spinal tuberculosis were L3 in 4 cases, L4 in 6, L5 in 4, and S1 in 2. The course of disease averaged 13 monthes (range 6 monthes to 6 years). The ESR of all cases was greater than 20 mm/h (average40 mm/h); WBC was normal in 14 cases, and a l ittle high in 2 cases. The X-ray picture showed narrow intervertebral space in 5 cases, compressed body of vertebra in 7 cases, and destroyed 2 consecutive vertebra and its sclerotin was condupl icate in 1 case. All cases were abscess in major psoas muscle. The CT showed destruction of bone, abscess-formation and dead bone in body of vertebra of 16 cases. The abscess were found in vertebral canal in 5 cases and dura mater of spinal cord and spinal nerve root crushed in 2 cases. The MRI showed destruction of bone, abscess-formation and hibateral abscess in major psoas muscle in 11 cases. The abscess were found in vertebral canal and dura mater of spinal cord and spinal nerve root crushed in 6 cases. The therapy of pasid was treated after operation in all the cases. Results Incision healed by first intention in 16 cases; and disruption of wound occurred and heal ing was achieved after symptomatic treatment in 1 case. Sixteen cases were followed up 2-5 years (29 months on average). Among all the cases, anaesthesia in double thigh was found in 3 cases, adynamia of dorsiflexion in foot in 1 case, gatism in 1 case; after 2 weeks the symptoms were vanished. Indirect hernia of fold inguen were found in 1 case after 2 years, and the patient refused operation for age and was no longer followed up. Fuzzy, exsic and acerb in eyes were foundin 6 cases, hearing disturbance were found in 2 cases, and symptoms were vanished after medication adjustment. Low-grade fever and lumbar myalgia were found in 1 case and cured after staying in bed and medication adjustment. All ESR were normal, synostosis of lumbosacral vertebral body was found in 13 cases, kyphosis in 1 case. Conclusion Internal fixation of spinal column by posterior approach and extraperitioneal bilateral focal debridement is safe and available way for the treatment of tuberculosis of lumbosacral vertebral body, it can save the times of operation, shorten period and enhance effect of treatment.
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.
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 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.
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.