OBJECTIVE: To review the clinical characteristics of patients with traumatic spinopelvic dissociation (SPD) and explore the diagnostic and therapeutic methods. METHODS: A clinical data of 22 patients with SPD who underwent surgical treatment between March 2019 and August 2024 was retrospectively analyzed. There were 13 males and 9 females, with an average age of 35.5 years (range, 14-61 years). The causes of injury included falling from height in 16 cases, traffic accidents in 5 cases, and compression injury in 1 case. Sacral fractures were classified based on morphology into "U" type (9 cases), "H" type (7 cases), "T" type (4 cases), and "λ" type (2 cases). According to the Roy-Camille classification, there were 4 cases of type Ⅰ, 12 cases of type Ⅱ, 2 cases of type Ⅲ, and 4 cases of type Ⅳ. The Cobb angle was (35.7± 22.0)°. Sixteen patients were accompanied by lumbosacral trunk and cauda equina nerve injury, which was classified as grade Ⅱ in 5 cases, grade Ⅲ in 5 cases, and grade Ⅳ in 6 cases according to the Gibbons grading. The time from injury to operation was 2-17 days (mean, 5.7 days). Based on the type of sacral fracture and sacral nerve injury, 6 cases were treated with closed reduction and minimally invasive percutaneous sacroiliac screw fixation, 16 cases were treated with open reduction and lumbar iliac fixation (8 cases)/triangular fixation (8 cases). Among them, 11 patients with severe fracture displacement and kyphotic deformity leading to sacral canal stenosis or bony impingement within the sacral foramen underwent laminectomy and sacral nerve decompression. X-ray films and CT were reviewed during followed-up. The Matta score was used to evaluate the quality of fracture reduction. At last follow-up, the Majeed score was used to assess the functional recovery, and the Gibbons grading was used to evaluate the nerve function. RESULTS: All operations were successfully completed. All patients were followed up 8-64 months (mean, 20.4 months). Two patients developed deep vein thrombosis of the lower limbs, 2 had incision infections, and 1 developed a sacral pressure ulcer; no other complications occurred. Radiological examination showed that the Cobb angle was (12.0±6.8)°, which was significantly different from the preoperative one ( t=6.000, P<0.001). The Cobb angle in 16 patients who underwent open reduction was (14.9±5.5)°, which was significantly different from the preoperative one [(46.8±13.9)° ] ( t=8.684, P<0.001). According to the Matta scoring criteria, the quality of fracture reduction was rated as excellent in 8 cases, good in 7 cases, fair in 5 cases, and poor in 2 cases, with an excellent and good rate of 68.2%. Bone callus formation was observed at the fracture site in all patients at 12 weeks after operation, and bony union achieved in all cases at last follow-up, with a healing time ranging from 12 to 36 weeks (mean, 17.6 weeks). At last follow-up, the Majeed score was rated as excellent in 7 cases, good in 10 cases, fair in 4 cases, and poor in 1 case, with an excellent and good rate of 77.3%. One patient experienced a unilateral iliac screw breakage at 12 months after operation, but the fracture had already healed, and there was no loss of reduction. Among the 16 patients with preoperative sacral nerve injury, 11 cases showed improvement in nerve function (6 cases) or recovery (5 cases). CONCLUSION SPD with low incidence, multiple associated injuries, and high incidence of sacral nerve injury, requires timely decompression of the sacral canal for symptomatic sacral nerve compression, fractures reduction, deformities correction, and stable fixation.
Humans ; Adult ; Female ; Male ; Retrospective Studies ; Middle Aged ; Spinal Fractures/diagnostic imaging* ; Adolescent ; Sacrum/diagnostic imaging* ; Fracture Fixation, Internal/methods* ; Young Adult ; Pelvic Bones/surgery* ; Treatment Outcome ; Bone Screws

OBJECTIVE: To explore the differences in the implantation safety and stability of a S ₁ alar-iliac screw (S1AIS) or S2AIS for sacroiliac joint fixation, providing reference for selecting appropriate internal fixation in clinical practice. METHODS: Patients who underwent pelvic CT examination between January 2024 and December 2024 were selected. CT data from 80 patients with normal pelvic structure who met the selection criteria were included in a 1∶1 male to female ratio. CT digital reconstruction technology was used to measure the transverse and longitudinal diameters of the S1AIS and S2AIS insertable ranges, as well as the length, width, and sacral side length of the screw trajectory. The pelvic CT data from 30 patients were randomly selected based on a 1∶1 male to female ratio for three-dimensional (3D) printing of pelvic samples. The S1AIS/S2AIS with a diameter of 6.5 mm and 8.0 mm were implanted at the optimal entry/exit points on the left and right sides, respectively, to observe the perforation of the screw trajectory. The pelvic CT data from 1 patient was randomly selected for 3D printing of 10 pelvic samples to simulate Tile C2 fracture. They were divided into S1AIS group ( n=5) and S2AIS group ( n=5), with one S1AIS and one S2AIS fixation used for posterior sacroiliac joint separation, and the specimen stiffness and maximum load were measured by using an electric tension torsion dual axis universal mechanical tester. RESULTS: The anatomical parameter measurement showed that there was no significant difference in the length and width of the screw trajectory between S1AIS and S2AIS ( P>0.05), but the transverse and longitudinal diameters of the insertable ranges, as well as the sacral side length of the screw trajectory, were all greater than those of S2AIS, with significant differences ( P<0.05). After simulating the implantation of S1AIS and S2AIS with a diameter of 6.5 mm in pelvic specimens, no screw penetration was observed. Both S1AIS and S2AIS with a diameter of 8.0 mm showed screw penetration, with S2AIS having a higher incidence of posterior lateral sacral cortical penetration (46.7%) than S1AIS (3.3%) ( P<0.05). The biomechanical test showed that the stiffness and maximum load of S2AIS were significantly lower than those of S1AIS ( P<0.05). CONCLUSION As a method to fix the sacroiliac joint, the S1AIS has a larger insertable range, a longer sacral side length of the screw trajectory, a lower incidence of posterior lateral cortical rupture of the sacrum, and a greater fixation strength than S2AIS. Therefore, the implantation safety and fixation stability of the S1AIS are superior to S2AIS, and a diameter less than 8.0 mm screws should be selected as S2AIS for Chinese people.
Humans ; Bone Screws ; Sacroiliac Joint/diagnostic imaging* ; Male ; Female ; Sacrum/diagnostic imaging* ; Fracture Fixation, Internal/instrumentation* ; Ilium/diagnostic imaging* ; Tomography, X-Ray Computed ; Middle Aged ; Adult ; Printing, Three-Dimensional ; Aged

PURPOSE: Percutaneous ilio-sacral screw (ISS) insertion using conventional C-arm fluoroscopy has been a widely employed technique for pelvic posterior ring fixation, particularly in developing regions. However, this approach presents technical challenges, leading to a high malposition rate. We introduced a new method for ISS insertion without additional equipment or software and suggested whether it could reduce the malposition rate and operating time. METHODS: This is a retrospective cohort study. The study included all patients who underwent percutaneous ISS fixation between January 2020 and December 2022. Patients treated with open reduction or other types of implants were excluded. The patients were divided into 2 groups based on the screw insertion method: Group A utilized the traditional dual-plane adjustment method, while Group B received the newly introduced method. In all cases, conventional C-arm fluoroscopy was the sole guidance during the surgical procedure. Malposition rate, radiation exposure, and operating time were compared between groups. Post-operative CT scans were used to assess screw accuracy using the Smith grading method. The Student's t-test or the Mann-Whitney U test was chosen for comparing the quantitative variables based on the normality test results. The Chi-squared test was utilized for comparing qualitative variables. RESULTS: A total of 72 patients with pelvic posterior ring disruption treated with percutaneous ISS under conventional fluoroscopy guidance were included in this study. Among them, 32 patients were in Group A and 40 patients were in Group B. In Group B, the average operation duration per screw was 33 min with 29 fluoroscopy applications, which was significantly lower than that in Group A (44 min, p < 0.001, 38 times, p < 0.001, respectively). Furthermore, the post-operative CT scan revealed that only 10.7% (6/56) of screws in Group B were inappropriately positioned according to the Smith criteria. CONCLUSION The novel method introduced in this study demonstrated a reduction in both malposition rates and operating time compared to the traditional dual-plane adjustment method. Precise pre-operative CT planning in conjunction with conventional fluoroscopy could establish this method as a widely applicable technique for percutaneous ISS fixation.
Humans ; Fluoroscopy/methods* ; Retrospective Studies ; Bone Screws ; Female ; Male ; Tomography, X-Ray Computed/methods* ; Sacrum/diagnostic imaging* ; Middle Aged ; Operative Time ; Adult ; Fracture Fixation, Internal/methods* ; Ilium/diagnostic imaging* ; Aged

OBJECTIVE: To precise classify sacral meningeal cysts, effective guide minimally invasive neurosurgery and postoperative personalized rehabilitation by multiple dimensions radiographic reconstruction MRI. METHODS: From March to December 2021, based on the original 3D-fast imaging employing steadystate acquisition (FIESTA) scanning sequence, 92 patients with sacral meningeal cysts were pre-operatively evaluated by multiple dimensional reconstruction MRI. The shape of nerve root and the leakage of cyst were reconstructed according to the direction of nerve root or leakage track showed on original MRI scans. Sacral canal cysts were accurately classified as including nerve root and without nerve root, so as to accurately design the incision of skin and formulate corresponding open range of the posterior wall of the sacral canal. Under the microscope intraoperation, the shape of the nerve roots inside cysts or leakage track of the cysts without nerve roots were verified and explored. After the reinforcement and shaping operation, several reexaminations of multiple dimensional reconstruction MRI were performed to understand the deformation of the nerve root and hydrops in the operation cavity, so as to formulate a persona-lized rehabilitation plan for the patients. RESULTS: Among the 92 patients with sacral mengingeal cyst, 58 (63.0%) cysts with nerve root cyst, 29 (31.5%) cysts without nerve root cyst, and 5 (5.4%) cysts with mixed sacral canal cyst. In 58 patients with nerve root cysts, the accuracy of preoperative clinical classification on MRI image reached 96.6% (56/58) through confirmation by operating microscope. Only 2 cases of large single cyst with nerve root on the head of cyst were mistaken for without nerve root type. In 29 patients with sacral cyst without nerve root, the accuracy of preoperative image reached 100% through confirmation by operating microscope. The accuracy of judging the internal nerve root and leakage of 12 cases with recurrent sacral cyst was also 100%. Two cases of delayed postoperative hydrops were found one month after operation. After rehabilitation treatment by moxibustion and bathing, the hydrops disappeared 4-6 months after operation. CONCLUSION Multiple dimensional reconstruction MRI can precisely make clinical classification of sacral meningeal cysts before operation, guide minimally invasive neurosurgery effectively, and improve the rehabilitation effect.
Humans ; Magnetic Resonance Imaging/methods* ; Male ; Female ; Sacrum/surgery* ; Adult ; Middle Aged ; Imaging, Three-Dimensional/methods* ; Cysts/rehabilitation* ; Aged ; Adolescent ; Young Adult ; Spinal Nerve Roots/diagnostic imaging* ; Minimally Invasive Surgical Procedures ; Neurosurgical Procedures/methods*

OBJECTIVETo evaluate the clinical effects of CT-guided percutaneous puncture and local chemotherapy for lumbosacral spinal tuberculosis.

METHODSFrom January 2002 to March 2013, 145 patients (84 males and 61 females) with lumbosacral spinal tuberculosis underwent failed conservative treatment were treated with CT-guided minimally invasive surgery. Their clinical data were retrospectively analyzed. Among them, 143 patients were followed up, aged from 2.5 to 81 years with an average of (42.60 +/- 17.14) years. Fourteen cases (6 cases with internal fixation and 8 cases without internal fixation) recurred and 32 cases complicated with paraspinal abscess after operation. Preoperatively 1 case complicated with lower limb weakness and superficial sensation worse, 1 case with muscle strength decrease, this 2 cases were grade D of Frankle, other cases were grade E. And 1 patient underwent fenestration operation and local chemotherapy, 144 cases with CT-guided percutaneous puncture and local chemotherapy. ESR and lumbar lordosis angle of all patients were observed preoperatively and final follow-up.

RESULTSThe mean follow-up time was 67 months (ranged, 21 to 149 months) in 143 cases, and 73 cases more than 5 years. All patients obtained clinical healing. ESR was (44.96 +/- 12.41) mm/h before operation and (7.25 +/- 3.43) mm/h at final follow-up, there was significant difference between preoperative and postoperative (t=35.06, P=0.000). Lumbar lordosis angle was (36.32 +/- 8.55) degrees before operation and (33.35 +/- 8.16) at final follow-up, there was significant difference between preoperative and postoperative (t=13.90, P=0.000).

CONCLUSIONWhen conservative treatment fails for 3 months or more, the patients have good spinal stabilization, nerve function is more than grade D of Frankel, CT-guided percutaneous puncture and local chemotherapy can get satisfactory outcomes for lumbosacral spinal tuberculosis.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; Debridement ; Female ; Humans ; Lumbosacral Region ; diagnostic imaging ; surgery ; Male ; Middle Aged ; Minimally Invasive Surgical Procedures ; Retrospective Studies ; Sacrum ; surgery ; Tomography, X-Ray Computed ; Tuberculosis, Spinal ; diagnostic imaging ; surgery ; Young Adult

BACKGROUNDA quantitative and accurate measurement of the range of hip joint flexion (RHF) is necessarily required in the evaluation of disordered or artificial hip joint function. This study aimed to assess a novel method to measure RHF more accurately and objectively.

METHODSLateral radiographs were taken of 31 supine men with hip joints extended or flexed. Relevant angles were measured directly from the radiographs. The change in the sacrofemoral angle (SFA) (the angle formed between the axis of the femur and the line tangent to the upper endplate of S1) from hip joint extension to hip joint flexion, was proposed as the RHF. The validity of this method was assessed via concomitant measurements of changes in the femur-horizontal angle (between the axis of the femur and the horizontal line) and the sacrum-horizontal angle (SHA) (between the line tangent to the upper endplate of S1 and the horizontal line), the difference of which should equal the change in the SFA.

RESULTSThe mean change in the SFA was 112.5 ± 7.4°, and was independent of participant age, height, weight, or body mass index. The mean changes in the femur-horizontal and SHAs were 123.0 ± 6.4° and 11.4 ± 3.0°, respectively. This confirmed that the change of SFA between hip joint extension and hip joint flexion was equal to the difference between the changes in the femur-horizontal and SHAs.

CONCLUSIONSUsing the SFA, to evaluate RHF could prevent compromised measurements due to the movements of pelvis and lumbar spine during hip flexion, and is, therefore, a more accurate and objective method with reasonable reliability and validity.

Adult ; Hip Joint ; diagnostic imaging ; surgery ; Humans ; Male ; Radiography ; Range of Motion, Articular ; physiology ; Sacrum ; diagnostic imaging ; surgery ; Young Adult

OBJECTIVETo introduce the location and course of S1, S2 sacral nerve root tunnel and to clarify the significance of the anterior aspect of sacral nerve root tunnel on placement of iliosacral screw on the standard lateral sacral view.

METHODSFirstly the data of 2.0 mm slice pelvic axial CT images were imported into Mimics 10.0, and the sacrum, innominate bones, and sacral nerve root tunnels were reconstructed into 3D views respectively, which were rotated to the standard lateral sacral views, pelvic outlet and inlet views. Then the location and course of the S1, S2 sacral nerve root tunnel on each view were observed.

RESULTSThe sacral nerve root tunnel started from the cranial end and anterior aspect of the vertebral canal of the same segment and ended up to the anterior sacral foramen with a direction from cranial-posterior-medial to caudal-anterior-lateral. The tunnel had a lower density than the iliac cortex and greater sciatic notch on the pelvic X-rays,especially on the standard sacral lateral view, on which it showed up as a disrupted are line and required more careful recognition.

CONCLUSIONIt can prevent the iliosacral screw from penetrating the sacral nerve root tunnel and vertebral canal when recognizing the anterior aspect of sacral nerve root tunnel and choosing it as the caudal-posterior boundary of the "safe zone" on the standard lateral sacral view.

Adult ; Aged ; Bone Screws ; Female ; Fracture Fixation, Internal ; Fractures, Bone ; surgery ; Humans ; Male ; Middle Aged ; Pelvic Bones ; diagnostic imaging ; injuries ; innervation ; surgery ; Radiography ; Sacrococcygeal Region ; diagnostic imaging ; innervation ; surgery ; Sacrum ; diagnostic imaging ; injuries ; innervation ; surgery ; Spinal Nerve Roots ; diagnostic imaging ; surgery ; Young Adult

Arachnoiditis ; diagnosis ; diagnostic imaging ; pathology ; Humans ; Lumbar Vertebrae ; diagnostic imaging ; pathology ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Radiography ; Sacrum ; diagnostic imaging ; pathology

OBJECTIVEFree-hand pedicle screw placement has a high incidence of pedicle perforation which can be reduced with fluoroscopy, navigation or an alternative rapid prototyping drill guide template. In our study the error rate of multi-level templates for pedicle screw placement in lumbar and sacral regions was evaluated.

METHODSA case series study was performed on 11 patients. Seventy-two screws were implanted using multi-level drill guide templates manufactured with selective laser sintering. According to the optimal screw direction preoperatively defined, an analysis of screw misplacement was performed. Displacement, deviation and screw length difference were measured. The learning curve was also estimated.

RESULTSTwelve screws (17%) were placed more than 3.125 mm out of its optimal position in the centre of pedicle. The tip of the 16 screws (22%) was misplaced more than 6.25 mm out of the predicted optimal position. According to our predefined goal, 19 screws (26%) were implanted inaccurately. In 10 cases the screw length was selected incorrectly: 1 (1%) screw was too long and 9 (13%) were too short. No clinical signs of neurovascular lesion were observed. Learning curve was insignificantly noticeable (P=0.129).

CONCLUSIONIn our study, the procedure of manufacturing and applying multi-level drill guide templates has a 26% chance of screw misplacement. However, that rate does not coincide with pedicle perforation incidence and neurovascular injury. These facts along with a comparison to compatible studies make it possible to summarize that multi-level templates are satisfactorily accurate and allow precise screw placement with a clinically irrelevant mistake factor. Therefore templates could potentially represent a useful tool for routine pedicle screw placement.

Aged ; Female ; Humans ; Imaging, Three-Dimensional ; Lumbar Vertebrae ; diagnostic imaging ; surgery ; Male ; Middle Aged ; Pedicle Screws ; Prosthesis Design ; Radiographic Image Interpretation, Computer-Assisted ; Retrospective Studies ; Sacrum ; diagnostic imaging ; surgery ; Spinal Diseases ; diagnostic imaging ; surgery ; Tomography, X-Ray Computed

OBJECTIVESTo introduce a classification system of upper sacral segment and its significance based on the continuous pelvic axial computed tomography scan.

METHODSThe whole pelvis 2.0 mm thick axial scan images of 127 cases were observed, the sacroiliac screw channel of S1 were measured, according to the size of the transverse screw channel the upper sacral segment were classified. Such as transverse screw channel existed and in at least 4 layer scan images its width was > 7.3 mm, it was defined as sacral segment of the normal type. Such as transverse screw channel existed and its maximum width was 7.3 mm or less on scanning level, it was defined as a transitional. Such as transverse channel did not exist, or its width on all scanning level was 0 mm or less, it was defined as dysplastic. Various cases,percentage, and the average of the transverse screw channel were calculated.

RESULTSThere were 58 normal (45.7%),42 transitional (33.1%), and 27 dysplastic (21.2%) upper sacral segments with an averaged width of the tansverse screw channel of 13.9 mm, 5.2 mm, and 0.9 mm, respectively. Each specimen could be defined as one of the three types of upper sacral segment without exceptions.

CONCLUSIONIt is possible to insert a transverse iliosacral screw into a normal upper sacral segment when indicated because of the capacious transverse screw channel. The transverse iliosacral screw placement into the transitional and dysplastic upper sacral segments was contraindicated because of the limited or none transverse screw channel. The transitional upper sacral segment was superior to the dysplastic segment due to its starting point location restriction on the true lateral sacral view.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Bone Density ; Bone Screws ; Female ; Fracture Fixation, Internal ; Humans ; Male ; Middle Aged ; Pelvic Bones ; diagnostic imaging ; surgery ; Sacrum ; diagnostic imaging ; surgery ; Tomography, X-Ray Computed ; Young Adult