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

OBJECTIVE: To define a safe distance range from the LC-Ⅱ screw trajectory to the apex of the greater sciatic notch based on pelvic CT measurements, and to clinically assess the feasibility of using this range under iliac oblique view combined with iliac tangential view fluoroscopy to guide screw insertion. METHODS: CT scans of 104 normal pelvises collected between January 2022 and February 2025 were analyzed. There were 52 males and 52 females, with a median age of 45.8 years (range, 19-76 years). The RadiAnt DICOM Viewer software was used to reconstruct coronal, sagittal, and axial sections of the potential LC-Ⅱ screw trajectory. The maximum safety distance (Dmax) and the optimal safety distance (Dopt) from this trajectory to the greater sciatic notch were measured on the coronal and sagittal views. A retrospective analysis was conducted on 21 patients with LC-Ⅱ type pelvic fractures treated with the LC-Ⅱ screws fixation. And the screws were placed within the pre-defined safe distance under guidance from the iliac oblique view and iliac tangential view. Postoperative CT scans were obtained to evaluate the accuracy of screw placement. RESULTS: Radiographic measurements from the 104 cases showed that Dmax ranged from 1.87 to 3.87 cm (mean, 2.79 cm), and Dopt ranged from 1.01 to 2.92 cm (mean, 1.84 cm). Both Dmax and Dopt were significantly greater in the males than in the females ( P>0.05). No significant difference was found between the left and right sides within the same gender ( P>0.05). All 21 patients successfully underwent fracture reduction and fixation, with a total of 23 LC-Ⅱscrews implanted. According to the Lonstein grading system, the screw placement accuracy was rated as excellent in 16 screws, good in 3, fair in 3, and poor in 1, with an excellent and good rate of 82.6%. CONCLUSION Utilizing a CT-defined safe distance range from the screw trajectory to the greater sciatic notch, and adhering to this range under iliac oblique view combined with iliac tangential view fluoroscopy, enables the accurate and precise placement of LC-Ⅱ screws.
Humans ; Male ; Female ; Middle Aged ; Bone Screws ; Adult ; Tomography, X-Ray Computed/methods* ; Aged ; Ilium/surgery* ; Pelvic Bones/diagnostic imaging* ; Fracture Fixation, Internal/instrumentation* ; Retrospective Studies ; Fluoroscopy ; Fractures, Bone/diagnostic imaging* ; Young Adult

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

Snapping hip syndrome is a relatively common problem that can be easily managed with conservative treatment. This syndrome can be divided into external, internal and intra-articular types. Internal snapping hip syndrome is the rarest amongst these and its etiology is not well understood. We report a unique case of osteochondroma arising from the anterior inferior iliac spine (AIIS), which caused the internal snapping hip syndrome with hip pain and restriction of activity. This rare case of snapping hip syndrome from the AIIS was treated surgically and the symptoms completely disappeared after excision of the tumor.
Adult ; *Bone Neoplasms ; Female ; *Hip Joint/diagnostic imaging/physiopathology ; Humans ; *Ilium/diagnostic imaging/physiopathology ; *Joint Diseases/etiology/physiopathology ; *Osteochondroma

Apophyseal injuries of the pelvis have increased recently with increased participation of teenagers in contact sports. Apophyseal fractures of the pelvis should be ruled out from apophysitis, os acetabuli and bony tumors. We report a case of fracture of anterior-inferior iliac spine following indirect injury to the hip in a young football player. The patient failed to get better with nonoperative management and continued to have pain in the left hip and signs and symptoms of impingement. He improved following surgical excision of the heterotopic bone and did not have any evidence of recurrence at 2 years follow- up.
Adolescent ; Athletic Injuries ; diagnostic imaging ; surgery ; Femoracetabular Impingement ; diagnostic imaging ; surgery ; Follow-Up Studies ; Football ; injuries ; Fracture Fixation ; adverse effects ; methods ; Fractures, Malunited ; diagnostic imaging ; surgery ; Humans ; Ilium ; diagnostic imaging ; injuries ; surgery ; Male ; Osteotomy ; methods ; Risk Assessment ; Spinal Fractures ; diagnostic imaging ; surgery ; Tomography, X-Ray Computed ; methods ; Treatment Outcome

BACKGROUNDMany clinical studies have been published involving the use of a high hip center (HHC), achieved good follow-up. However, there is a little anatomic guidance in the literature regarding the amount of bone stock available for initial implant coverage in this area of the ilium. The purpose of this study was to evaluate the thickness and width of the human ilium and related acetabular cup coverage for guiding acetabular component placement in HHC.

METHODSA total of 120 normal hips in 60 cases of adult patients from lower extremities computer tomographic angiography Digital Imaging and Communications in Medicine data were chosen for the study. After importing the data to the mimics software, we chose the cross sections every 5-mm increments from the rotational center of the hip to the cephalic of the ilium according the body sagittal axis, then we measured the thickness and width of the ilium for each cross section in axial plane, calculated the cup coverage at each chosen section.

RESULTSAt the acetabular dome, the mean thickness and width of the ilium were 49.71 ± 4.88 mm and 38.92 ± 3.67 mm, respectively, whereas at 1 cm above the dome, decreased to 41.35 ± 5.13 and 31.13 ± 3.37 respectively, and 2 cm above the dome, decreased to 31.25 ± 4.04 and 26.65 ± 3.43, respectively. Acetabular cup averaged coverage for 40-, 50-, and 60-mm hemispheric shells, was 100%, 89%, and 44% at the acetabular dome, 100%, 43.7%, and 27.5% for 1 cm above the dome, and 37.5%, 21.9%, and 14.2% for 2 cm above the dome.

CONCLUSIONSHHC reconstructions within 1 cm above the acetabular dome will be an acceptable and smaller diameter prosthesis would be better.

Adult ; Aged ; Cross-Sectional Studies ; Female ; Hip Prosthesis ; Humans ; Ilium ; anatomy & histology ; diagnostic imaging ; Male ; Middle Aged ; Radiography

OBJECTIVETo radiographically analyze the osseous fixation zone for the iliac crest external fixation with Schanz screws and in order to guide their placement.

METHODSNine adults with 2.0-mm-slice continuous pelvic axial CT scans were selected as research subjects. Each CT scan data was imported into MIMICS 10.0. The osseous fixation zone the upper portion of the anterior column of the acetabulum which is located between the anterior superior iliac spine and the gluteal medius pillar and between the iliac crest and the acetabulum-for the iliac crest external fixation with Schanz screws was reconstructed into true sagittal and true coronal planes by using the software. Then the measurements were taken on the reconstructed planes with measuring tools. Finally, the measured data was analyzed.

RESULTSThe palpable iliac crest segment, which was of 49.6 mm width and located 16.5 mm posterior to the anterior superior iliac spine could be used to locate the start points of the Schanz screws. Under the above-mentioned iliac crest segment, the osseous zone was deep, got ample bony materials and could intraosseously contain Schanz screws with 5.0 mm diameter. The screws could be safely inserted to a minimal depth of 71.7 mm towards the acetabular dome and to a maximal depth of 143.5 mm posterior to the acetabulum.

CONCLUSIONThe study can guide the effective insertion of the iliac crest Schanz screws. By setting a suitable start point in the above-mentioned iliac crest region and angling correctly relative to the acetabulum,the Schanz screw can be inserted into the relative strong cancellous bone above or posterior to the acetabulum with a considerable depth, to getting more bone engagement.

Adult ; Aged ; Bone Screws ; Female ; Fracture Fixation ; Fractures, Bone ; diagnostic imaging ; surgery ; Humans ; Ilium ; diagnostic imaging ; injuries ; surgery ; Male ; Middle Aged ; Orthopedic Procedures ; Tomography, X-Ray Computed

Adamantinoma ; diagnostic imaging ; metabolism ; pathology ; surgery ; Adult ; Diagnosis, Differential ; Female ; Femur ; Follow-Up Studies ; Humans ; Humerus ; Ilium ; Keratins ; metabolism ; Male ; Middle Aged ; Mucin-1 ; metabolism ; Retrospective Studies ; Sarcoma, Ewing ; pathology ; Sarcoma, Synovial ; pathology ; Tibia ; Tomography, X-Ray Computed ; Young Adult

Actins ; metabolism ; Bone Neoplasms ; blood ; complications ; diagnostic imaging ; pathology ; surgery ; Diagnosis, Differential ; Female ; Humans ; Hypophosphatemia ; blood ; etiology ; Ilium ; Mesenchymoma ; blood ; complications ; diagnostic imaging ; pathology ; surgery ; Middle Aged ; Osteomalacia ; blood ; etiology ; Phosphates ; blood ; Platelet Endothelial Cell Adhesion Molecule-1 ; metabolism ; Tomography, X-Ray Computed

Osseous hemangioma is a benign vascular tumor, and it usually occurs in the vertebrae and the skull. However, hemangiomas of flat bones are rare, and there are very few reports that describe the radiologic findings of osseous hemangioma of the ilium. We report a unique case of large cavernous hemangioma mimicking a chondrogenic malignant bone tumor originated from the ilium in a 22-year-old female. The mass showed stippled calcifications, heterogeneous enhancement with thick septa and enhanced soft tissue components on CT and MR, and also this mass demonstrated heterogeneous 2-fluoro [fluorine-18]-2-deoxy-D-glucose (18F-FDG) uptake on 18F-FDG PET/CT.
Bone Neoplasms/radionuclide imaging ; Diagnosis, Differential ; Female ; Fluorodeoxyglucose F18/*diagnostic use ; Hemangioma, Cavernous/*radionuclide imaging ; Humans ; Ilium/*blood supply ; Magnetic Resonance Imaging ; Positron-Emission Tomography and Computed Tomography ; Radiopharmaceuticals/*diagnostic use ; Young Adult