Sacroiliac Research Articles

CT-Based Evaluation of Volumetric Posterior Pelvic Bone Density with Implications for the Percutaneous Screw Fixation of the Sacroiliac Joint.

Background: Operative treatment of fragility fractures of the pelvis has become a gold standard. Preoperative planning, including the assessment of the pathway for iliosacral screws, is crucial. The anchorage of the screw depends on the bone quality. Some recent studies have concentrated on assessing bone mineral density (BMD) with the use of Hounsfield unit (HU) values obtained from CT scans. The aim of the present study is to determine the best sacral levels of S1-S3 on the pathway of iliosacral screws for sacroiliac joint fixation. Methods: Patients admitted to the Independent Public Healthcare Center in Rypin between 1 of September and 1 of December in 2023, who had CT scans of the pelvis performed on them for different reasons, were included in this study. In total, 103 patients-56 men and 47 women-were enrolled in the study and consecutively separated into two groups of different ages: 18-60 years old (group A) and above 60 years old (group B). The volumetric bone density expressed in HU values was measured with sacral levels of S1, S2 and S3. Apart from the bodies of sacral vertebrae S1-S3, our measurements involved the ala of the ilium in the vicinity of the sacroiliac joint and the wing of the sacrum. All the measurements were performed on the pathway of presumptive iliosacral screws to stabilize the sacroiliac joint. Results: In group A (58 patients) the highest bone density in sacral bodies was found in S1 that gradually decreased to S3, while the opposite tendency was demonstrated in the ala of ilium. The HU values in the wing of the sacrum did not display statistical significance. In group B (45 patients), the highest bone density was also found in the sacral body S1 that decreased toward S3 but in the ala of ilium, the highest bone density was found with level S1 and lowest with level S2. In both groups, the highest bone density referred to the wing of the sacrum. Conclusion: While the perfect construct for posterior pelvic ring fixation remains unclear, our findings may imply that sacroiliac joint screws inserted into the wing of the sacrum of greater bone density could provide much more successful fixation in comparison to those anchored in the body of sacral vertebra of lesser bone density.

Severe multiple injuries in a 15-year-old boy with pelvic fracture complete anterior dislocation of the sacroiliac joint and rupture of the internal and external iliac arteries: A case report of a rare injury.

Anterior dislocation of the sacroiliac joint combined with pelvic fractures is relatively rare in clinical practice. It is often associated with hemodynamic instability and severe injuries to other regions, resulting in a complex condition, prolonged treatment duration, and high rates of mortality and disability. However, there are few reports in the literature describing the diagnosis and treatment of anterior dislocation of the sacroiliac joint. In this case, the patient sustained a pelvic fracture with anterior sacroiliac joint dislocation and rupture of both the internal and external iliac arteries following a motor vehicle accident, making it an even rarer and more challenging case to treat. Reporting such cases can enhance the understanding of the diagnosis and treatment of anterior sacroiliac joint dislocation with rupture of the iliac arteries and provide valuable references for similar cases. The patient was riding an electric bicycle and was hit by a small truck, resulting in a pelvic fracture, anterior dislocation of the sacroiliac joint, and rupture of the internal and external iliac arteries. The patient was diagnosed with open pelvic fracture (type C1.2), left complete anterior dislocation of the sacroiliac joint, left acetabular fracture, left internal and external iliac arteriovenous rupture. emergency room resuscitation, intensive care unit resuscitation, 6 surgeries and perioperative management. He has been discharged from the hospital for more than 1 year and was rechecked every month after discharge, the fracture has healed, there is no obvious pain and discomfort in and around the wound, he has been fitted with a prosthesis, and he is doing the walking function exercise. Pelvic fracture with anterior sacroiliac dislocation is clinically rare and critical, and is associated with large vessel rupture, severe organ damage, and high mortality and disability rates. Rapid restoration of pelvic stability and hemodynamic stability is the key to treatment. Rapid transfer to a tertiary trauma center, rapid examination through the green channel to clarify the diagnosis, close intensive care, and reasonable multidisciplinary teamwork for surgical intervention are all valuable experiences that we have concluded.

Calprotectin as a marker of disease activity in spondyloarthritis

Introduction: Spondyloarthritis is a group of arthritic diseases that classically manifest as inflammation of the sacroiliac and limb joints, as well as the axial skeleton. Microscopic bowel inflammation is identifiable in over 50% of these patients. Calprotectin measured in the serum and stool is an emerging surrogate marker of disease activity and/or bowel inflammation in spondyloarthritis. Objective: This article aims to review published literature to determine the accuracy of serum and faecal calprotectin levels for use in monitoring bowel inflammation and spondyloarthritis disease activity. Methods: Boolean operator strategy was used to search two databases (Embase and PubMed) and 52 relevant articles were identified. Duplicate results were eliminated, inclusion and exclusion criteria were applied. Results: Ten studies met the inclusion criteria and were summarized and analyzed. The EBL Validity questionnaire was applied to determine study quality. All research articles found calprotectin to be elevated in spondyloarthritis patients when compared to controls. Faecal calprotectin was superior in detecting disease activity and correlated with disease activity questionnaires, radiology and endoscopy results. Only one study assessed the effect of treatment on calprotectin and its correlation to bowel inflammation. Conclusion: Faecal calprotectin shows promise as a surrogate marker for disease activity and bowel inflammation in spondyloarthritis. Future studies should focus on the effect of treatment on faecal calprotectin and whether some treatments are better at preventing the progression of bowel inflammation in addition to treating spondyloarthritis. Supplementary investigations are needed to identify whether faecal calprotectin is useful as a marker of disease activity in response to treatment.

A Case Report of Successful Off-Label Neuromodulation for Concurrent Refractory Sacroiliac Pain and Phantom Limb in a Hip Disarticulation Patient

Hip disarticulation is a morbid procedure for those whose bony or soft tissues are unable to be salvaged. It involves extensive resection, and the patient featured in this report expressed mechanical pain from their sacroiliac joint (SIJ) as well as phantom limb pain (PLP). Spinal cord stimulation is known to assist with neuropathic pain syndromes, and SIJ fusion is effective in these cases of multifactorial pain. This report presents a successful off-label use of thoracic spinal cord stimulation in a complex pain condition consisting of coexisting PLP and mechanical SIJ pain in a hip disarticulation patient.

Stabilization of 82 sacroiliac luxations in 67 cats using two sacroiliac screws (2014-2023).

To describe sacroiliac luxation stabilization in cats using two screws and to report clinical and radiographic short-term outcomes. Retrospective clinical cohort study. Cats (n = 67) with sacroiliac luxation. Case records of cats presented for sacroiliac luxation stabilized using two screws per side affected, one lag and one positional, between 2014 and 2023 were reviewed. The percentage of sacral purchase (PoSP) for each screw, percentage of reduction (PoR), and pelvic canal width ratio (PCWR) were measured and calculated. Eighty-two sacroiliac luxations were stabilized. Two 2.0 mm screws were used in 69 cases; two 2.4-mm screws in nine cases, and one 2.4 mm with one 2.0 mm screw in four cases. The mean PoSPs for lag and positional screws were 46% ± 12 and 31% ± 11, respectively. The median PoR was 89% (41 to 100). The mean PCWR was 1.23 ± 0.11. Clinical follow up was available for 42 cats with 53 sacroiliac luxations at a median of 87 days (36 to 2503). The full function was noted in 34 patients (81%). Screw failure occurred in five sacroiliac joints (4.7%), including loosening (n = 3), and breakage (n = 2) of the positional screws (n = 1). Pelvic canal diameter was maintained in all cases. Excellent functional and radiographic outcomes were obtained for cats with sacroiliac luxation stabilized with two sacroiliac screws. Feline sacroiliac luxation can be stabilized using two sacroiliac screws.

8557 Osteitis Fibrosa Cystica as the Initial Manifestation of Severe Primary Hyperparathyroidism: A Case Report

Abstract Disclosure: L.A. Robles Gomez: None. G. Gill: None. A. Vincent, DO: None. A. Mahmoud, MD: None. Introduction: Osteitis fibrosa cystica (OFC) is a pathognomonic yet uncommon finding of hyperparathyroidism seen in less than 2% of patients with primary hyperparathyroidism in Western countries. We present a case of infrequent finding of late-stage severe hyperthyroidism with asymptomatic hypercalcemia and incidental findings of osteolytic bone lesions. Clinical Case: A 28-year-old female with a history of PCOS, fatigue, and chronic abdominal pain presents to the clinic after recent work-up during an ED visit demonstrated incidental findings of osteolytic bone lesions in the setting of mild hypercalcemia. Physical examination was relatively unremarkable except for mild tenderness to palpation on the right lower quadrant. Laboratory significant calcium 10.7 mg/dl (8.6-10.2 mg/dL), albumin 3.6 g/dL, Creatinine 0.56 mg/dL, GFR 127 mL/min, Alkaline phosphatase 187 IU/L (37-127 IU/L), AST 24 IU/L, ALT 45 IU/L, Intact PTH and calcium: PTH 413 pg/mL (15-65 pg/mL), Calcium 11.5 (8.7-10.4 mg/dL), Bone Specific Alkaline Phosphatase: 54.5 mcg/L (4.7-17.8 mcg/L), Phosphorus 2.1 mg/dL (2.4-4.8 mg/dL), Magnesium 1.7 mg/dL (1.5-2.5 mg/dL), Vitamin D 25 10 mg/mL (20-100 ng/mL), TSH 2.12 uIU/mL (0.46-5.05 uIU/mL). CT abdomen pelvis w/o contrast with multiple predominantly lytic expansile bone lesions, mainly in the pelvis, with the most extensive 6.2 cm lesion in the superior, posterior right ilium, the anterior acetabulum, and the posterior right ischium. A prior CT done in 2018 showed a similar distribution of lytic lesions. The patient denied any previous personal or family history of hypercalcemia or parathyroid abnormalities despite a review of prior outside records revealed abnormal labs dating back to 2018 with intact PTH 406 pg/mL, calcium 10.3 mg/dL, Ionized calcium 10.7 mg/dl (3.30-6.0 mg/dL), albumin 3.3g/dL, alkaline phosphatase 288 IU/L. The patient denied prior symptomatology of hypercalcemia, including renal stones, or prior treatment for hypercalcemia. Further work-up was ordered, and the patient was referred to endocrine surgery for management. Conclusion: Osteitis fibrosa cystica (OFC) has become a rare manifestation of primary hyperparathyroidism (PHPT) due to early diagnosis of hypercalcemia by routine lab monitoring. Skeletal findings typically seen on PHPT can vary from bone reabsorption-acroosteolysis, subchondral bone resorption, brown tumors, salt-and-pepper skull, and osteopenia. Subchondral reabsorption around specific joints commonly affects pubic symphysis and sacroiliac joints, as seen in our patient. The mechanism is due to PTH-mediated osteoclastic absorption of bone and surrounding cartilage. Due to the rare presentation of PHPT with associated osteitis fibrosa cystica, diagnosis requires a high degree of clinical suspicion, as delayed diagnosis can lead to avoided manifestation, as described by our report. Presentation: 6/3/2024

Obstetric and neonatal outcomes in women with Ankylosing spondylitis - an evaluation of a population database

BackgroundAnkylosing Spondylitis (AS) is a systemic chronic rheumatic disease characterized by involvement of the axial skeletal and sacroiliac joints. Although this disease is not rare amongst women of reproductive age, data regarding pregnancy outcomes have demonstrated conflicting results. We therefore aimed to compare pregnancy and perinatal outcomes between women who suffered from AS to those who did not.MethodsA retrospective cohort study using the Healthcare Cost and Utilization Project, Nationwide Inpatient Sample (HCUP-NIS). Included in the study were all pregnant women who delivered or had a maternal death in the US between 2004 and 2014. Women with an ICD-9 diagnosis of AS before or during pregnancy were compared to those without. Pregnancy, delivery, and neonatal outcomes were compared between the two groups using multivariate logistic regression models adjusting for potential confounders.ResultsA total of 9,096,788 women were inclusion in the analysis. Amongst them, 383 women (3.8/100,000) had a diagnosis of AS and the rest were controls. Women with AS, compared to those without, were more likely to be older; Caucasian; from higher income quartiles; suffer from thyroid disorders, and have multiple pregnancies (p < 0.001, all). After adjusting for confounders, patients in the AS group, compared to those without, had a higher rate of cesarean delivery (CD) (aOR 1.47, 95% CI 1.14–1.91, p = 0.003); gestational diabetes (aOR 1.55, 95% CI 1.02–2.33, p = 0.038); and placenta previa (aOR 3.6, 95% CI 1.6–8.12, p = 0.002). Regarding neonatal outcomes, patients with AS, compared to those without, had a higher rate of small-for-gestational-age (SGA) neonates (aOR 2.19, 95% CI 1.22–3.93, p = 0.009); and intrauterine fetal death (IUFD) (aOR 3.46, 95% CI 1.11–10.83, p = 0.033).ConclusionWomen diagnosed with AS have an increased risk of obstetric complications, including CD, as well as an increased risk of SGA and IUFD.

Performance analysis of a deep-learning algorithm to detect the presence of inflammation in MRI of sacroiliac joints in patients with axial spondyloarthritis

ObjectivesTo assess the ability of a previously trained deep-learning algorithm to identify the presence of inflammation on MRI of sacroiliac joints (SIJ) in a large external validation set of patients...

Standing versus supine pelvic incidence in adult spinal deformity patients.

Pelvic incidence (PI) is commonly used to determine sagittal alignment. Historically, PI was believed to be a fixed anatomic parameter. However, recent studies have suggested that there is positionally-dependent motion that occurs through the sacroiliac joint (SIJ) resulting in changes in PI. We reviewed 100 consecutive adult spinal deformity (ASD) patients seen at our academic tertiary referral center. Two reviewers measured pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and lumbar lordosis (LL) on standing radiographs and scout computed tomography scans (CT). Unilateral, bilateral, or absent SIJ vacuum sign (VS) was determined using CTs. Eighty-six patients (42M:44F) were included with an average age of 64.1 years and BMI of 28.8kg/m2. Standing PI was low (< 50°) in 35 patients (40.7%), average (50°-60°) in 22 (25.6%), and high (> 60°) in 29 (33.7%). Average and high PI patients had significant PI changes of 3.0° (p = 0.037) and 4.6° (p = 0.005), respectively. Bilateral SIJ VS was seen in 68 patients, unilateral VS in 9, and VS was absent in 9. The average change in PI between standing and supine was 2.1° in bilateral SIJ VS patients (p = 0.045), 2.2° in unilateral SIJ VS (p = 0.23), and - 0.1° in patients without SIJ VS (p = 0.93). The average absolute difference in PI between supine and standing was 5.5° ±5.5° (p < 0.001). There is a change in PI from supine to standing. In patients with high PI and bilateral VS on CT, the change from supine to standing is significant, perhaps representing instability of the SIJ.

Comparison of a Novel Posterior Integrated Transfixation Sacroiliac Joint Fusion Approach to the Posterolateral and Lateral Approaches: A Cadaveric Biomechanical and Computational Analysis of the Fixation, Invasiveness, and Fusion Area.

To concurrently assess and compare the fixation efficacy, invasiveness, and fusion potential of a posterior integrated transfixation cage system to the posterolateral threaded implant and lateral triangular rod systems, in a cadaveric model. Twelve (12) cadaveric sacroiliac joint specimens were utilized and tested within the single-leg stance multidirectional pure moment bending model. Each specimen was tested in the intact, destabilized, treated (using posterior, posterolateral, and lateral systems), and post-fatigue conditions by applying 0 to ± 7.5 Nm of moment in flexion-extension, axial rotation, and lateral bending while measuring the angular range of motion between the sacrum and ilium. Computational models were reconstructed from Computed Tomography (CT) scans and manufacturer surgical technique guides. The models were utilized to quantify the volume of bone removed during implantation and the surface area available for fusion. The posterior integrated transfixation cage system and the lateral triangular rods produced equivalent motion reduction in all motion planes (P > 0.583). The posterolateral cylindrical threaded implant produced less motion reductions than the posterior and lateral implants in flexion-extension (6% ± 3% vs 37% ± 10% and 33% ± 11%, respectively, P <0.05). The posterior system removed 22%-60% less bone volume from the sacrum and ilium (P<0.10), introduced 200%-270% more implant surface to the joint space (P<0.01) and decorticated 75%-375% more joint surface area (P<0.01). The posterior integrated transfixation single-implant cage system is superior to the posterolateral cylindrical threaded single-implant system. Its performance in osteopenic bone is equivalent to the lateral triangular rod system in healthy bone; however, the posterior integrated transfixation cage system requires a single implant, while the lateral triangular rod system requires three. The posterior implant removes the least bone volume and has the most surface area for fusion, providing a significantly better opportunity for robust sacroiliac joint arthrodesis.

An investigation into process parameters optimization for ultimate tensile strength of friction stir welded Al-10Mg-8Ce-3.5Si joint: Numerical and Design of Experiments approach

An investigation into process parameters optimization for ultimate tensile strength of friction stir welded Al-10Mg-8Ce-3.5Si joint: Numerical and Design of Experiments approach

ID: 338075 Improvement in Gait Abnormality following Minimally Invasive, Posterior Approach Sacroiliac Joint Fusion

ID: 338075 Improvement in Gait Abnormality following Minimally Invasive, Posterior Approach Sacroiliac Joint Fusion

A clinical assessment of preperitoneal packing adequacy for pelvic fracture bleeding control

BackgroundThis study aimed to objectively assess the laparotomy pads to potential hemorrhage sites proximity in pelvic fracture patients who underwent post-pre peritoneal packing (PPP) CT scans with packs in situ. MethodsThe CT scans of 19 patients were assessed to measure the distance between laparotomy pads and predetermined pelvic anatomical landmarks. ResultsA total of 38 measurements showed that the median pack-to-point distance for the sacroiliac joint was 2.7 cm (IQR, 2.1–4.0), for the common iliac artery 4.1 cm (IQR, 3.2–5.0), for the external iliac artery 0 cm (IQR, 0.0–0.2), for the internal iliac artery 0.1 cm (IQR, 0–0.7), and for the iliac bifurcation 2.0 cm (IQR, 1.7–3.9). There were 60 % direct contact measurements for the iliac arteries. ConclusionThis study shows that with adequately executed PPP a reasonable proximity of laparotomy packs to the potential bleeding sites to provide tamponade for arresting hemorrhage may be achieved.

Prospective Trial of Sacroiliac Joint Fusion Using 3D-Printed Triangular Titanium Implants: 5-Year Follow-Up.

Prospective, multicenter, single arm study with 5-year follow up. To report long-term (5-year) safety, effectiveness, and radiographic outcomes after sacroiliac (SI) joint fusion (SIJF) with 3D-printed triangular titanium implants (TTI) and compare them with solid titanium plasma spray coated implants. A large literature base supports minimally invasive SIJF with TTI for chronic SIJ dysfunction. SIJF with TTI was performed in 51 subjects and scheduled follow-up occurred at 3, 6, 12, 24 and 60 months. Postoperative visits included quality of life questionnaires and functional tests. A high-resolution CT scan was performed at either 6 or 12 months, and again at 60 months. All CT scans were interpreted by an independent musculoskeletal radiologist. 5-year follow-up was available in 36 of 51 subjects (71%). At 5 years, improvements in SI joint pain (58.1 points [0-100 scale]), SIJ-related disability (Oswestry Disability Index [ODI], 25.4 points) and quality of life (EuroQOL 5D, 0.24 points, and EuroQOL visual analog scale, 13.4 points) were sustained and showed no signs of diminution. The percentage of patients using opioids for SIJ pain decreased markedly from baseline (57%) to 5 years (17%). Physical function tests showed persistent improvements from baseline. There was no evidence of device breakage, migration or subsidence and few late adverse events occurred attributable to the device. Independent analysis of CT scans showed bone opposed to implants in all cases, and evidence of bone bridging in 90% of cases, and no evidence of radiolucency or other adverse bone reactions. Prospective 5-year follow-up showed that SIJ fusion using 3D-printed TTI resulted in immediate, marked, and persistent improvements in pain and quality of life, with improved physical function, reduced opioid use, and a low rate of revision surgery. Radiographic evidence showed implant integration and joint fusion. Level II.

Effectiveness of intra-articular analgesia in reducing postoperative pain after minimally invasive sacroiliac joint fusion: a double-blind randomized controlled trial

During the first postoperative days following minimally invasive sacroiliac joint fusion (MISJF), patients often report serious pain, which contributes to high utilization of painkillers and prevention of early mobilization. This prospective, double-blind randomized controlled trial investigates the effectiveness of intraoperative SIJ infiltration with bupivacaine 0.50% versus placebo (NaCl 0.9%) in 42 patients in reducing postoperative pain after MISJF. The primary outcome was difference in pain between bupivacaine and placebo groups, assessed as fixed factor in a linear mixed model. Secondary outcomes were opioid consumption, patient satisfaction, adverse events, and length of hospital stay. We found that SIJ infiltration with bupivacaine did not affect postoperative pain scores in comparison with placebo, neither as group-effect (p = 0.68), nor dependent on time (group*time: p = 0.87). None of the secondary outcome parameters were affected in the postoperative period in comparison with placebo, including opioid consumption (p = 0.81). To conclude, intra-articular infiltration of the SIJ with bupivacaine at the end of MISJF surgery is not effective in reducing postoperative pain. Hence, we do not recommend routine use of intraoperative SIJ infiltration with analgesia in MISJF.

Epidural Analgesia for Palliative Pain Management for A Patient with An Advanced Stage Prostate Cancer: A Case Report

Introduction: Patients with advanced-stage cancer should be able to stay at home with their families without suffering from pain. This case report aims to discuss challenges in pain management of a patient with bone metastasis of prostate cancer who received epidural analgesia at home. Challenges were related to the patients, health professionals, and system. Understanding each factor will bring insights to develop a workable pain management program in the palliative setting. Case Presentation: A 66-year-old male was diagnosed with left sacroiliac joint pain due to metastatic prostate cancer. After a three-year history of prostate cancer and ineffective chemotherapy, the patient complained of pain in the left hip that did not improve with conventional medications (paracetamol, tramadol, and Morphine Sustained Release/MST). In response, the consideration of an epidural implant emerged as a potential solution, offering the prospect of home-based care and autonomous medication administration through an epidural continuous block with intermittent drug injection. Conclusions: This case highlights home-based interventional pain management for cancer, addressing challenges at the patient, health professional, and system level. Overcoming these challenges requires a multidisciplinary approach and robust institutional policies. The insights gained offer valuable lessons for hospitals aiming to enhance the competence of pain and palliative care teams and establish comprehensive support systems in hospital and home settings.

The Ghost Of Hip Arthroplasties Past: It Takes A Geriatrician To Mine For Metal

Abstract Background An 84-year-old female presented to Geriatric Medicine out-patient clinic with many years of persistent right hip pain, generalised myalgia; and several months of constipation, weight loss and persistent elevation of C-reactive protein and Erythrocyte Sedimentation Rate. The General Practitioner's concern was occult neoplasm. History of right hip arthroplasty in 2011. 6 years prior, she had wide local excision and adjuvant radiotherapy for a grade 3, “triple negative”, invasive ductal carcinoma of the right breast. Serial imaging identified a right parasternal, internal mammary chain neurofibroma. A Rheumatologist had administered intra-articular steroid to both glenohumeral joints for plain X-ray confirmed osteoarthritis, in the absence of serological vasculitic or autoimmune rheumatological disease. Benefit was transient. Her Oncologist had arranged MRI spine for “sciatica” demonstrating L3/4 and L4/5 stenosis and a large right adnexal cyst. Subsequently, the Gynaecology team assessed and planned interval MRI pelvis as initial MRI suggested a right partial hydrosalpinx, left internal chain lymphadenopathy and nodule adjacent to sacroiliac joint. Methods History, examination and imaging results were checked against the Medical Device Alert number 18 from the Medicines and Healthcare products Regulatory Agency (UK) in 2017. Oxford Hip Score Assessment was 29. Lymphatic drainage from medial hip joint is towards right iliac chain. Results In the absence of Gadolinium based contrast agents within 96hours, metal testing demonstrated: Serum Cobalt was 232nmol/L or 13.7 ug/L; Serum Chromium was 78.8nmol/L or 4.1ug/L; Chromium Urine: Creatinine Urine Ratio was 24.54nmol/mmol; and Cobalt Urine: Creatinine Urine Ratio73.96nmol/mmol. These elevated blood and urine results confirmed metal-on-metal hip disease. Conclusion Consider symptomatic metal-on-metal hip disease with soft-tissue involvement in patients presenting with post-hip arthroplasty joint pain, generalised myalgia and raised inflammatory markers; particularly if there is unexplained ipsilateral internal iliac chain lymphadenopathy and pelvic fluid collections. If confirmed, metalwork explanation is the treatment.

Improving surgical technical skills for emergency fixation of unstable pelvic ring fractures: an experimental study using a pelvic ring fracture simulator

BackgroundThe management of hemodynamically unstable pelvic ring injuries necessitates surgical intervention, often involving procedures such as external fixation and percutaneous screw placement. Given the infrequent performance of these procedures, regular training is imperative to ensure readiness for emergencies. Our pre- post simulation study aimed to adapt and validate a realistic simulation model for stabilizing unstable pelvic ring injuries, facilitating participants’ knowledge retention and procedural confidence enhancement.MethodsA standardized simulator of an unstable pelvic ring utilizing synthetic pelvic bones featuring complete disruption of the symphysis and sacroiliac joint was developed. Trauma surgeons of a level one academic hospital were invited to perform external fixation and emergency sacroiliac screw application under C-arm guidance. Prior to and following the simulation session, participants completed a subjective questionnaire assessing their confidence in emergency interventions on a 10-point Likert scale (10-LS). Objective parameters, such as intraoperative imaging quality, reduction accuracy, and the positioning of screws, wires, and external fixators, were also evaluated as secondary outcome measures.ResultsFifteen trauma surgeons (10 residents, 5 consultants) participated in the simulation over the course of one day. The mean total operation time was 20.34 ± 6.06 min, without significant differences between consultants and residents (p = 0.604). The confidence for emergency SI-Screw placement increased significantly after the simulator (10-LS: Before = 3.8 ± 3.08 vs. After = 5.67 ± 2.35; p = 0.002) as well as after external fixation (10-LS: Before = 3.93 ± 2.79 vs. After = 6.07 ± 2.52; p = 0.002). In addition, confidence in (intraoperative) pelvic imaging increased significantly (10-LS: Before = 4.60 ± 3.0 vs. After = 6.53 ± 2.39; p = 0.011). Overall, the model was rated as a realistic simulation of clinical practice (10-LS = 7.87 ± 1.13).ConclusionsOur unstable pelvis fracture model is a tool to practice emergency interventions such as external fixation and percutaneous techniques. Participants benefitted from this in terms of technical instrumentation as well as intraoperative imaging. Further studies are required to validate the objective benefits and improvements that participants undergo through frequent training.

Bone assessment of the sacroiliac joint in ankylosing spondylitis: Comparison between computed tomography and zero echo time MRI

PurposeTo demonstrate the clinical applicability of zero echo time magnetic resonance imaging (ZTE MRI) in bone assessment of the sacroiliac joint in ankylosing spondylitis. MethodBetween January 2021 and November 2021, twenty-one ankylosing spondylitis patients underwent clinically indicated MRI including ZTE sequence, in addition, all patients underwent a CT scan covering the sacroiliac joints within 6 months of the MRI examination. The sensitivity, specificity, and accuracy of ZTE MRI were calculated using CT as the reference standard. Cohen’s κappa tests were applied to assess the agreement of positive imaging findings (including erosions, osteosclerosis, bony cystic changes, and joint space changes) between MRI and CT as well as the inter-reader agreement for the grading of sacroiliitis in AS patients. ResultsThere was no statistical significance between ZTE MRI and CT in detecting of ankylosing spondylitis(p＞0.05). The consistency of the diagnosis of positive imaging findings between ZTE MRI and CT was moderate to excellent (ranging from 0.611 to 0.889), and the consistency of the scores of positive imaging was good to excellent (ranging from 0.857 to 0.979). ConclusionsZTE MRI provides “CT-like” contrast for bony changes of the sacroiliac joint in ankylosing spondylitis and could simplify and reduce costs for some AS patients when both MRI and CT are typically required.

Modular Hemipelvic Prosthesis Preserves Normal Biomechanics and Showed Good Compatibility: A Finite Element Analysis.

This study aimed to evaluate the biomechanical compatibility of a modular hemipelvic prosthesis by comparing stress distributions between an implanted pelvis and a healthy pelvis. Finite element analysis was used to simulate bilateral standing loads on both models, analyzing critical regions such as the sacroiliac joints, iliac crest, acetabulum, and prosthesis connection points. Six models with varied displacements of the hip joint rotational center were also introduced to assess the impact of deviations on stress distribution. The implanted pelvis had a stress distribution closely matching that of the intact pelvis, indicating that the prosthesis design maintained the biomechanical integrity of the pelvis. Stress patterns in displacement models with deviations of less than 10 mm were similar to the standard model, with only minor changes in stress magnitude. However, backward, upward, and inward deviations resulted in stress concentrations, particularly in the prosthesis connection points, increasing the likelihood of mechanical failure. The modular hemipelvic prosthesis demonstrated good biomechanical compatibility with minimal impact on pelvic stress distribution, even with moderate deviations in the hip joint's rotational center; outward, forward, and downward displacements are preferable to minimize stress concentration and prevent implant failure in cases where minor deviations in the rotational center are unavoidable during surgery.