Plate fixation of inferior ramus in pubis-ischium ramus improves mechanical stability in Tile B pelvic injures: a cadaveric biomechanical analysis and early clinical experience.

BACKGROUND: Management of inferior ramus of the pubis-ischium ramus remains controversial, and related research is sparse. The main intention of this study is to describe the biomechanical and clinical outcomes of pubis-ischium ramus fractures in Tile B pelvic injuries and to identify the feasibility and necessity of fixation of the inferior ramus of the pubis-ischium ramus. METHODS: This study comprised two parts: a biomechanical test and a retrospective clinical study. For the biomechanical tests, Tile B-type pelvic injuries were modeled in six cadaver specimens by performing pubis-ischium osteotomies and disruption of the anterior and interosseous sacroiliac ligaments. The superior and/or inferior rami of the pubis-ischium ramus were repaired with reconstruction plates and separated into three groups (A, B, and C). Specimens were placed in the standing position and were loaded axially with two-leg support for three cycles at 500 N. The displacements of sacroiliac joints at osteotomy were measured with Vernier calipers and compared using statistical software. To investigate the clinical outcomes of this technique, 26 patients were retrospectively analyzed and divided into a superior ramus fixation group (Group D) and a combined superior and inferior ramus of the pubis-ischium ramus fixation group (Group E). The main outcome measures were time of operation, blood loss, postoperative radiographic reduction grading, and functional outcomes. RESULTS: In the vertical loading test, Group E showed better pelvic ring stability than Group D (P < 0.05). However, the shift of the sacroiliac joints was almost identical among the three groups. In our clinical case series, all fractures in Group E achieved bony union. Group E demonstrated earlier weight-bearing functional exercise (2.54 ± 1.45 vs 4.77 ± 2.09; P = 0.004), earlier bony union (13.23 ± 2.89 vs 16.55 ± 3.11; P = 0.013), and better functional outcomes (89.77 ± 7.27 vs 82.38 ± 8.81; P = 0.028) than Group D. The incidence of sexual dysfunction was significantly lower in Group E than that in Group D (2/13 vs 7/13; P = 0.039). Bone nonunion occurred in two patients in Group D, and two patients in Group E had heterotopic ossification. None of the patients exhibited wound complications, infections, implant failures, or bone-implant interface failures. CONCLUSIONS: Fixation of the inferior ramus of a pubis-ischium ramus fracture based on conventional fixation of the anterior pelvic ring is mechanically superior in cadaveric Tile B pelvic injury and shows rapid recovery, good functional outcomes, and low incidence of complications.

The imaging diagnosis and differential diagnosis of Ewing’s sarcoma in ilium,pubis,and ischium / 实用放射学杂志

Objective To investigate the imaging findings of Ewing’s sarcoma in ilium,pubis,and ischium,and to improve the diagnostic veracity.Methods The imaging manifestations of 1 5 patients with pathologically proved Ewing’s sarcoma in ilium,pubis or ischium were retrospectively analyzed.All the 1 5 patients were underwent X-ray examination.Among them,12 cases performed CT examination and 1 1 cases performed MRI examination.Results In all the 1 5 Ewing’s sarcoma patients,8 lesions located at the iliac.7 lesions located at the pubic and ischial.12 cases showed simple osteolytic bone destruction on X-ray images,3 cases showed mixed bone destruction.All the 1 5 cases showed soft-tissue mass around the lesion.On CT images,7 cases showed swelling in the periphery of the lesion areas and internal osteolytic bone destruction,5 cases showed irregular oateomas,hyperosteogeny or osteo-sclerosis surrounding bone destruction areas,6 cases showed irregular periosteal reactionsurrounding the lesion areas,12 cases showed soft-tissue mass surrounding the lesion areas.On MRI,7 cases showed long T1 and long T2 signal,4 caese showd T1 low and T2 heterogeneous high signal,5 cases showed high signal in the fat suppression sequences.All the 1 1 cases who underwent MRI examination showed bone destruction and soft tissue mass on MRI.Conclusion Although rare,Ewing’s sarcomas of the ilium,pu-bis,and ischium have some certain image features.X-ray,CT and MRI examinations play an important role in the diagnosis and dif-ferent diagnosis of these conditions.