Hip Bone Research Articles

Age estimation on post-mortem CT based on pelvic bone mineral density measurement and the state of putrefaction: a multivariate method.

Age-at-death estimation is an important issue in forensic medicine and anthropology. Initially, methods relied on morphological criteria, but with the advancement of radiology, new techniques such as morphological studies on multi-slice computed tomography (CT) reconstructions have emerged. Recent studies have shown promising results by investigating the correlation between age and bone mineral density (BMD). However, there is currently a lack of data on post-mortem CTs (PMCT) involving decomposed bodies, and limited information exists regarding changes in Hounsfield Units measurement in a post-mortem context. In light of these gaps, our study aimed to examine the relationship between age at death and pubic and ilium BMD using a sample of forensic bodies. We also aimed to determine whether post-mortem processes, such as putrefaction, could interfere with this correlation. Our retrospective analysis encompassed 637 PMCTs conducted before medicolegal autopsies at Tours University Hospital. Utilizing simple and multiple linear regressions, we investigated the correlation between age and pubic and ilium BMD, as well as the relationship between BMD and the radiologic alteration index (RAI), a scale employed to quantify the degree of putrefaction. Our findings indicate promising outcomes in age-at-death estimation using pubic and/or ilium BMD for bodies exhibiting no or moderate decomposition (RAI < 80), particularly among individuals under 40years old. However, for highly decomposed corpses (RAI ≥ 80), the presence of gas infiltration significantly influences the BMD of both the ilium and pubis. Consequently, we advocate for the incorporation of the RAI score into the age estimation equation to enhance the accuracy of our results in such cases. Further investigation involving a larger cohort of decomposed bodies could facilitate refinement and validation of our method within this specific population.

Estimation of Height at Withers Based on Long Bone Measurements of Living Cats

In this study, coefficients enabling estimation of shoulder height were obtained by taking morphometric measurements from radiographic images of live cats using the radiogrammetric method. For this purpose, a total of 37 adult cats, including 17 females and 20 males, were involved. While the effect of sexual dimorphism was observed on the morphometric data, the presence of sexual dimorphism was only evident in the coefficients (factors) of the humerus and talus. No significant effect of gender was found on the shoulder height estimation coefficients (factors) for other thoracic and pelvic limb bones. Gender had an impact on the slenderness index in all thoracic limbs, but only on the tibia slenderness index among the pelvic limb bones. Generally, female individuals were found to have more slender limbs. It is believed that the obtained coefficients (factors) and index data will contribute significantly to the prediction of archaeological cat morphology.

Developmental Patterns and Risk Factors of Scoliosis After Hemipelvectomy for the Pelvic Bone Tumor

Background: Postoperative scoliosis is often seen after hemipelvectomy for malignancies involving the pelvic area, but the details remain unclear. The objectives were to investigate the development patterns and risk factors of scoliosis after hemipelvectomy. Methods: We retrospectively reviewed 30 patients who underwent hemipelvectomy at our hospital between 1998 and 2020. The risk factors of scoliosis with a Cobb angle of ≥10° were investigated. Results: The postoperative Cobb angle significantly increased in all patients compared with the preoperative one (p &lt; 0.001), and the change ratio of the Cobb angle was significantly higher during the first postoperative year than thereafter. The external hemipelvectomy (EH) group demonstrated a larger Cobb angle and a higher change ratio than the internal hemipelvectomy group. Nine patients developed scoliosis with a final Cobb angle of ≥10°, and the risk factors were EH (p = 0.017), P1+2+3+4 resection according to the Enneking classification (p = 0.005), iliac crest resection (p = 0.004), L5/S resection (p = 0.020), and no pelvic ring reconstruction after hemipelvectomy (p = 0.004). Conclusions: Approximately 30% of patients who underwent hemipelvectomy developed scoliosis with a Cobb angle of ≥10°, and this angle increased rapidly during the first postoperative year. Hence, careful follow-up of scoliosis is required after hemipelvectomy.

Six-degrees-of-freedom pelvic bone monitoring on 2D kV intrafraction images to enable multi-target tracking for locally advanced prostate cancer.

Patients with locally advanced prostate cancer require the prostate and pelvic lymph nodes to be irradiated simultaneously during radiation therapy treatment. However, relative motion between treatment targets decreases dosimetric conformity. Current treatment methods mitigate this error by having large treatment margins and often prioritize the prostate at patient setup at the cost of lymph node coverage. Treatment accuracy can be improved through real-time multi-target adaptation which requires simultaneous motion monitoring of both the prostate and lymph node targets. This study developed and evaluated an intrafraction pelvic bone motion monitoring method as a surrogate for pelvic lymph node displacement to be combined with prostate motion monitoring to enable multi-target six-degrees-of-freedom (6DoF) tracking using 2D kV projections acquired during treatment. A method to monitor pelvic bone translation and rotation was developed and retrospectively applied to images from 20 patients treated in the TROG 15.01 Stereotactic Prostate Ablative Radiotherapy with Kilovoltage Intrafraction Monitoring (KIM) trial. The pelvic motion monitoring method performed template matching to calculate the 6DoF position of the pelvis from 2D kV images. The method first generated a library of digitally reconstructed radiographs (DRRs) for a range of imaging angles and pelvic rotations. The normalized 2D cross-correlations were then calculated for each incoming kV image and a subset of DRRs and the DRR with the maximum correlation coefficient was used to estimate the pelvis translation and rotation. Translation of the pelvis in the unresolved direction was calculated using a 3D Gaussian probability estimation method. Prostate motion was measured using the KIM marker tracking method. The pelvic motion monitoring method was compared to the ground truth obtained from a 6DoF rigid registration of the CBCT and CT. The geometric errors of the pelvic motion monitoring method demonstrated sub-mm and sub-degree accuracy and precision in the translational directions ( , , ) and rotational directions ( , , ). The 3D relative displacement between the prostate and pelvic bones exceeded 2, 3, 5, and 7mm for approximately 66%, 44%, 12%, and 7% of the images. Accurate intrafraction pelvic bone motion monitoring in 6DoF was demonstrated on 2D kV images, providing a necessary tool for real-time multi-target motion-adapted treatment.

Pseudomyogenic Hemangioendothelioma: A Case Report of a Rare Tumor with Unusual Presentation

Abstract Introduction/Objective Pseudomyogenic hemangioendothelioma (PHE) is an extremely rare neoplasm recently categorized by the World Health Organization (WHO) as an intermediate-grade vascular soft tissue tumor affecting young adults. While most documented cases exhibit local aggressiveness, we present a case with unusual presentation characterized by multiple pelvic and femoral lytic bone lesions associated with documented liver metastases. Methods/Case Report A mid-forties female presented with progressive left hip pain persisting for 2 weeks. Radiological assessments showed multiple lytic lesions in the left superior pubic ramus, right iliac wing, and left greater trochanter with associated pathologic fractures and soft tissue involvement. Additionally, multiple indeterminate hepatic and splenic hypodensities were noted. Histologic examination of the bone and liver biopsies revealed a neoplasm composed of spindled and epithelioid cells with hyperchromatic nuclei and eosinophilic cytoplasm. The neoplastic cells are arranged haphazardly and in short fascicles within a fibromyxoid stroma or sinusoidal spaces (in the liver) associated with scattered acute and chronic inflammation. Frequent mitoses are noted; however, no necrosis was identified. Tumor cells were positive for CD31, ERG, FOSB with equivocal staining for pankeratin and CK8/18. The top differential consideration was epithelioid hemangioendothelioma (EHE); however, sarcoma fusion next-generation sequencing panel exhibited features of a vascular neoplasm with WWTR1-FOSB, favoring PHE. Results (if a Case Study enter NA) NA Conclusion Pseudomyogenic hemangioendothelioma is a rare tumor that is prone for local recurrence and usually affect young adults (mean age: 30 years). Metastases are uncommon. To the best of our knowledge, we report a case of PHE with unusual presentation of early metastases to liver and possibly the spleen and highlights the complexity of PHE diagnosis.

Surgeon perspectives on a virtual reality platform for preoperative planning in complex bone sarcomas

Background and objectivesTreatment of primary bone and soft tissue sarcomas typically includes complete surgical resection with or without adjunctive modalities. Despite best efforts, for the most challenging clinical scenarios such as axial or pelvic sarcoma, five-year survival rates are reported to be between 27 and 40 %. Since quality of resection is a key determinant of oncologic outcomes, it is critical to preoperatively plan the surgical approach to improve resection accuracy, ensure sufficient surgical margins, and reduce the risk of local or metastatic recurrence. The computer conversion of 2-dimensional (2D) computerized tomography (CT) and magnetic resonance imaging (MRI) to a three-dimensional (3D) virtual reality (VR) avatar image may allow improved preoperative estimation of tumor size, location, adjacent anatomy, and spatial understanding of the tumor without relying on surgeon experience, memory, and imagination. The purpose of this study is to investigate the utility of a virtual reality platform in preoperative planning and surgical approach in a retrospective cohort of pelvic bone sarcoma cases. MethodsThe histopathology database at our institution was queried for all historical cases of bone and soft tissue sarcoma with surgical resection failure, defined as positive gross or microscopic margins. Four cases of pelvic bone sarcoma were chosen for retrospective review by fellowship-trained orthopedic tumor specialists. For each case, participants first studied conventional 2D preoperative CT images and answered a questionnaire pertaining to objective case parameters. Participants then interacted with case-specific 3D models while wearing a VR headset and answered the same questionnaire. The VR ‘avatar’ was created with custom-developed software. After using both modalities, participants completed a Likert-scale survey aiming to evaluate the VR technology's subjective impact on understanding tumor environment, surgical plan confidence, and its ability to improve communication with colleagues and patients. Four attending orthopedic oncologists, one orthopedic oncology fellow, and one senior orthopedic oncology resident participated in the study. ResultsFour cases of failed resection were evaluated by a group of both attending surgeons and a group of trainees composed of both residents and fellows. Tumor borders were clearly delineated in 0 % and 66.6 % cases when evaluating with conventional 2D imaging and VR, respectively. Participants changed adjacent structure involvement grade 22.2 % of the time after assessing involvement grade on the VR technology, with adjacent ligamentous structure grading changed most frequently in 55.5 % of cases. Users reported they would change the surgical approach or margins 44.4 % of the time after reviewing with VR technology. Initial 6 plane resection plans were changed in every user case. Subjective responses indicated that surgeons expressed more confidence in their approach, confidence with obtaining negative margins, and provided more detail regarding structures to be resected in specific planes. ConclusionPelvic tumors present unique surgical challenges due to complex 3D anatomy, the proximity of vital structures, consistency of the tumor, and the need to alter patient position during resection procedures. Using examples of failed pelvic bone sarcoma resections, our study found that VR imaging increased understanding of the tumor environment, characteristics, and ability to communicate with patients and colleagues.

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.

The landscape of Functional Outcome Measures Used in Patients with Bone Sarcoma of the Lower Extremity or Pelvis: A Systematic Review.

This systematic review provides a structured overview of the measurement instruments of functional outcome used in lower extremity and pelvic bone sarcoma patients. We identified 42 unique instruments covering 18 distinct functional outcome constructs with most studies measuring constructs within the activity domain of the International Classification of Functioning, disability, and health. The MusculoSkeletal Tumor Society 1993 and 1987 score, Toronto Extremity Salvage Score, and range of motion instruments were the measurement instruments most commonly used.

Accuracy of pelvic bone segmentation for 3d printing: a study of segmentation accuracy based on anatomic landmarks to evaluate the influence of the observer.

3D printing has a wide range of applications and has brought significant change to many medical fields. However, ensuring quality assurance (QA) is essential for patient safety and requires a QA program that encompasses the entire production process. This process begins with imaging and continues on with segmentation, which is the conversion of Digital Imaging and Communications in Medicine (DICOM) data into virtual 3D-models. Since segmentation is highly influenced by manual intervention the influence of the users background on segmentation accuracy should be thoroughly investigated. Seventeen computed tomography (CT) scans of the pelvis with physiological bony structures were identified, anonymized, exported as DICOM data sets, and pelvic bones were segmented by four observers with different backgrounds. Landmarks were measured on DICOM images and in the segmentations. Intraclass correlation coefficients (ICCs) were calculated to assess inter-observer agreement, and the trueness of the segmentation results was analyzed by comparing the DICOM landmark measurements with the measurements of the segmentation results. The correlation between segmentation trueness and segmentation time was analyzed. The lower limits of the 95% confidence intervals of the ICCs for the seven landmarks analyzed ranged from 0.511 to 0.986. The distance between the iliac crests showed the highest agreement between observers, while the distance between the ischial tuberosities showed the lowest. The distance between the upper edge of the symphysis and the promontory showed the lowest deviation between DICOM measurements and segmentation measurements (mean deviations < 1mm), while the intertuberous distance showed the highest deviation (mean deviations 14.5-18.2mm). Investigators with diverse backgrounds in segmentation and varying experience with slice images achieved pelvic bone segmentations with landmark measurements of mostly high agreement in a setup with high realism. In contrast, high variability was observed in the segmentation of the coccyx. In general, interobserver agreement was high, but due to measurement inaccuracies, landmark-based approaches cannot conclusively show that segmentation accuracy is within a clinically tolerable range of 2mm for the pelvis. If the segmentation is performed by a very inexperienced user, the result should be reviewed critically by the clinician in charge.

Investigation of pelvic floor influence on prostate displacement in image-guided radiotherapy.

The uncertainty of target location during prostate cancer radiotherapy plays an important role in accurate dose delivery and radiation toxicity in adjacent organs. This study analyzed displacement correlations between the prostate and pelvic floor. We retrospectively analyzed registration results from 467 daily cone-beam computed tomography (CT) in 12 patients with prostate cancer who received radiation therapy. We analyzed prostate displacement and the pelvic floor relative to the pelvic bone's anatomy in the translational and rotational directions and identified statistical correlations. The systematic (Σ) and random (σ) displacements of the prostate in the three translational directions, anterior-posterior (AP), superior-inferior (SI), and right-left (RL), were 1.49 ± 1.45, 2.10 ± 1.40, and 0.24 ± 0.53 mm, respectively, and in the rotational directions of the pitch, roll, and yaw were 2.10 ± 2.02°, 0.42 ± 0.74°, and 0.42 ± 0.64°, respectively. The pelvic floor displacements were 2.37 ± 1.96, 2.71 ± 2.28, and 0.47 ± 0.84 mm in the AP, SI, and RL directions, respectively, and 0.93 ± 1.49°, 0.98 ± 1.28 °, and 0.87 ± 0.94° in the pitch, roll, and yaw directions, respectively. Additionally, there were statistically significant correlations between the displacement of the prostate and pelvic floor in the AP and SI directions, with correlation coefficients (r) of 0.74 (p < 0.001) and 0.69 (p < 0.001), respectively. The movement of the pelvic floor may be an important factor that causes prostate displacement, affecting the accuracy of radiotherapy. Therefore, it is necessary to take appropriate measures to ensure that the pelvic floor muscle tension is as consistent as possible in the treatment' CT scan and daily treatment.

Modal and harmonic analysis of femur bone using different boundary conditions by Finite Element Analysis.

The longest and largest bone in the human body is the femur. Pelvic bone sustains the weight of the body to which the femur bone is connected. Many researches have been carried out to identify the behaviour of the femur bone. The study aimed to explore the natural frequencies and mode shapes of vibrating devices to gain insights into the dynamic behavior of the femur bone during various physical activities. Examining the impact of patient-specific bone shape and density on bone natural frequencies is crucial. The primary goals of femur bone analysis involve employing computer simulations for fracture detection and employing Finite Element (FE) models to determine natural frequencies and vibration modes. To obtain the natural frequency of the femur bone, different boundary conditions such as free-fixed and fixed-fixed are applied. Avoiding the coincidence of the natural frequency with external excitation frequencies is crucial to prevent femur bone fractures. Also, for different magnitude of loads, femur bone is involved in harmonic analysis is to identify the amplitude and stress against acceleration.

8031 Pelvic Fracture Related to Brown Tumor in Severe Secondary Hyperparathyroidism

Abstract Disclosure: M. Bodenstab: None. M. Lieberman-Ulm: None. V.S. Lagari-Libhaber: None. Background: Severe hyperparathyroidism can result in end-organ damage to the skeleton, known as osteitis fibrosa cystica (OFC). Histologically, OFC manifests as “Brown tumors”, which are so named due to the hemosiderin deposition that occurs from recurring microtraumas with subsequent hemorrhage. Typical sites of presentation include the mandible, clavicle, ribs, or pelvis, but can occur anywhere in the body. Patients can present with diffuse bone pain, pathological fracture, or bone deformities, though some may be asymptomatic and diagnosed incidentally. While these tumors do not have malignant potential, they can become debilitating in their burden and mimic malignant disease. Treatment focuses on treating the underlying cause of the hyperparathyroidism. Clinical Case: A 52-year-old female with ESRD on thrice weekly hemodialysis secondary to T2DM and HTN presented with right thigh pain and difficulty bearing weight, which began one week after a mechanical fall from standing. X-ray on admission revealed acute nondisplaced pathologic fracture of the right superior pubic ramus related to an underlying 4.7 x 2.2 cm expansile osteolytic lesion. Calcium level corrected for albumin on admission was 9.3 mg/dL, phosphorous 5.6 mg/dL, and PTH 563 pg/mL. Review of our institution’s electronic medical record revealed a maximum PTH level of 1,808 pg/mL three months prior. On CT pelvis, the patient was found to have multiple osteolytic lesions also involving the sacrum, multiple vertebral bodies, and the left pubic ramus, concerning for metastatic disease. Patient underwent pelvic rami bone biopsy resulting as osteoclast type giant cells, hemosiderin deposition and fibrosis in keeping with "brown tumor" of hyperparathyroidism. The patient was started on Cinacalcet 30 mg daily, with plans to titrate as outpatient to target PTH levels. She was also instructed to continue calcium, vitamin D and calcitriol to treat the underlying condition of metabolic bone disease from CKD. Referrals were given for both orthopedic spine and orthopedic oncology for surgical evaluation of her lesions. Discussion: Osteitis fibrosa cystica has become exceedingly rare in the United States and occurs in about 2% of patients with hyperparathyroidism. Due to their low prevalence and radiologic similarity to neoplasm, “Brown tumors” may be mistaken for metastatic disease and can lead to delay in diagnosis. Histology reveals collections of osteoclasts due to excess activity intermixed with fibrous tissue and poorly mineralized woven bone, which will differentiate brown tumor from malignancy. However, further correlation with hypercalcemia and hyperparathyroidism is imperative as brown tumors and other giant cell-containing lesions may be difficult to differentiate histologically. We present this case due to its rarity in clinical practice. Presentation: 6/2/2024

12243 The Case of a Metastatic Papillary Thyroid Cancer Presenting as an Unresectable Pelvic Mass

Abstract Disclosure: M. Tucktuck: None. Y. El Soufi: None. O.G. Adeniran: None. A.A. Gliwa: None. Background: Papillary thyroid cancer (PTC) represents around 85% of all thyroid cancers, of which 2-10% of patients will present with metastasis distant to the neck. The frequency of bone metastasis in PTC occurs in only 1-4% of patients. Studies have shown that distant and multi-organ metastasis is associated with higher mortality rates. Clinical case: A 69-year-old woman with diabetes mellitus, cerebrovascular accident, and right lower extremity deep venous thrombosis, presented with right foot and hip pain for 1 week after a mechanical fall. She had a 50 pound weight loss over a year without personal or family history of thyroid cancer or disease or radiation exposure. A soft and nontender mass in the right lower abdomen was noted during a physical exam. Imaging revealed a large heterogeneous lesion (16.3 x 13.3 x 15.5 cm) in the right bony pelvis with internal necrosis, destructing the right iliac bone, and extending into the right sacrum, acetabulum, and musculature, with mass effect on the surrounding vasculature, and enlarged lymph nodes suspicious for metastasis. Thyroid imaging showed a hypervascular hyperechoic 1.3 cm nodule within the right thyroid gland and a large 2 cm left thyroid nodule with scattered microcalcifications. Thyroid function tests were within normal limits. The patient underwent an initial ultrasound guided biopsy of the pelvic mass with indiscriminate results, and later a laparoscopic excisional biopsy of the pelvic mass showed neoplastic papillary proliferation with typical nuclear features, without necrosis or associated ovarian tissue. The immuno-histopathological profile was positive for PAX-8, TTF-1, thyroglobulin, and CK7, and the Ki-67 proliferation index was ∼20-30%. The patient was diagnosed with papillary thyroid cancer with metastasis to the pelvic bone, and was classified as stage IV, cT1bN0M1. As the pelvic mass was inoperable, the patient completed total thyroidectomy and was started on hormone replacement therapy. Subsequent thyroid pathology report was negative for papillary carcinoma. Further review of imaging did not show ectopic thyroid tissue in the neck or an ovarian pathology. Before the patient’s next visit to evaluate for struma ovarii, she passed away. Conclusion: Thyroid cancer is usually treated through thyroidectomy or lobectomy, with radioiodine (RAI) therapy as an effective treatment for differentiated cancers. Our patient, who presented with extremity pain revealing a distant metastasis, completed thyroidectomy with plans to undergo RAI therapy. Our case highlighted the importance of recognizing musculoskeletal presentations as an initial and possibly only finding of a distant metastasis. It also emphasized the utility of multidisciplinary collaboration in detecting and recognizing PTC as a primary thyroid cancer, as early management can reduce mortality and lead to more favorable outcomes. Presentation: 6/2/2024

6722 Increase in Femoral Neck BMD After Parathyroidectomy in Patients with Mild Primary Hyperparathyroidism

Abstract Disclosure: F. Abdul Kather: None. G.A. Clines: None. C. Janney: None. D.T. Hughes: None. N.H. Esfandiari: None. S. Saberi: None. Objective: This study aimed to assess changes in bone mineral density (BMD) following parathyroidectomy in patients with mild primary hyperparathyroidism, defined as serum calcium 10.4 mg/dl to 11.2 mg/dl, by comparing distinct patient variables. Hypothesis: Pre-op demographic factors, laboratory values, and BMD significantly influence post-parathyroidectomy BMD. Methods: This retrospective chart review included 93 subjects with primary hyperparathyroidism who underwent parathyroidectomy between 2000-2022 with BMD measurements performed at the same site pre- and post-parathyroidectomy. Exclusion criteria were age &amp;lt;50 years, GFR &amp;lt;30, recurrent primary hyperparathyroidism, chronic oral glucocorticoid use (&amp;gt;1 month), rheumatoid arthritis, suppressed serum TSH, hormone-deprivation therapy, cinacalcet use, and prescription osteoporosis medication therapy. Statistical analyses were performed using ANOVA and a p-value of &amp;lt;0.05 was considered statistically significant. Results: The mean age of the subjects was 63.65 ± 6.58 years, who were mostly female (84.9%) and white (88.2%). Pre-op laboratory values revealed mean uncorrected calcium 10.52 ±0.26 mg/dL, corrected calcium 10.25 ± 0.32 mg/dL, 25-OH vitamin D 35.82 ±15.31 ng/mL, and parathyroid hormone (PTH) 99.12 ±37.06 pg/mL. Pre-op mean bone densities for the lumbar spine, femoral neck, and total hip were 1.04 ± 0.16, 0.81 ± 0.11, and 0.87 ± 0.11 g/cm2, respectively, with corresponding T-scores of -1.13 ± 1.23, -1.60 ± 0.74, and -1.13 ± 0.89. Changes in BMD post-parathyroidectomy were determined by comparing pre-op and post-op DXA scans. No statistically significant differences in DXA were found between ages of 50-55 vs. &amp;gt;55, post-op timing of DXA 1-2 years post parathyroidectomy vs. &amp;gt;2 years post parathyroidectomy, number of parathyroid glands removed, the total weight of resected parathyroid glands, pre-op vitamin D level &amp;lt;30 ng/mL vs. ≥30 ng/mL, or pre-op urinary calcium levels &amp;lt;200 mg/day vs. ≥200 mg/day. Grouping subjects by pre-operative DXA T-scores revealed a statistically significant improvement in femoral neck bone density between osteoporotic and osteopenic subjects (p=0.018) and between osteoporotic and normal bone density subjects (p=0.019). No significant differences were identified in the spine and total hip bone density changes among these groups. Conclusion: In subjects with osteoporosis undergoing parathyroidectomy, a significant improvement in femoral neck bone density was observed, unaffected by pre-op variables of age, timing of DXA post parathyroidectomy, parathyroid gland characteristics, and pre-op vitamin D and urinary calcium levels. These findings underscore the potential for tailored interventions in managing bone health post-parathyroid surgery, emphasizing the need for personalized approaches to optimize outcomes in individuals with mild hyperparathyroidism. Presentation: 6/2/2024

12460 Bilateral Parietal Thinning: A Rare Condition Of Unclear Etiology

Abstract Disclosure: T.L. Madsen-Barbosa: None. M. Cheikh: None. I. Marcano: None. Background: Bilateral parietal bone thinning (BPT) is an infrequent and often underdiagnosed condition characterized by the external thinning of the skull's parietal bone. The pathophysiology is unclear, but some studies suggest a link to osteoporosis. We present a case of osteoporosis diagnosed on evaluation of BPT. Case Description: A 77-year-old woman with a history of chronic kidney disease (CKD stage IV) and type 2 diabetes was referred to the Bone Health Clinic for evaluation of low bone density. She initially presented to Neurosurgery clinic for evaluation of head indentations. A dual energy x-ray absorptiometry (DEXA) scan showed values in osteopenia range (left total hip bone mineral density (BMD) 0.678 and T-score of -2.2, left femoral neck BMD 0.272 and T-score of -1.6, and left 33% radius BMD 0.577 and T-score of -2.0), leading to the referral. The patient reported painless indentations in the parietal bones that had been progressing for four years, with no history of head trauma, inflammatory disease, or prolonged steroid use. A head computed tomography (CT) scan showed symmetric thinning of the skull’s parietal bones, with an average thickness of 2.34 mm (compared to 5.1 mm four years earlier). Review of prior images also revealed a T11 compression fracture on spine X-ray from 2019. Laboratory tests showed elevated parathyroid hormone (PTH) 155 pg/mL (reference range 15-65 pg/mL), low vitamin D 25-OH 10.6 ng/mL (reference range 30-100 ng/mL), elevated alkaline phosphatase 142 units/L (reference range 46-116 units/L), and high creatinine level 2.7 mg/dL (reference range 0.5-0.8 mg/dL), other laboratory tests were normal. After discussion with the patient and Nephrology, Denosumab therapy along with Calcium and Vitamin D supplementation were started in November 2023. The patient continues the treatment with antiresorptive medication every 6 months and head CT scan to monitor the skull thinning changes. Discussion: BPT is rare, with only approximately 150 cases reported. Crucial aspects such as its etiology, pathophysiology, treatment, and prognosis remain unknown. It can result from various conditions like trauma, systemic mastocytosis, diabetes mellitus, hereditary diseases, or idiopathic causes and mainly affects women of advanced age. Osteoporosis is suggested as a possible cause based on histological findings on prior studies that propose BPT may result from osteoporosis-induced decreased bone formation rather than increased bone destruction. The reason for excessive bone resorption in the skull of osteoporotic patients remains unclear. Our case highlights progressive and symmetric BPT possibly related to systemic conditions like osteoporosis, with a focus on treatment options. Conclusion: This case sheds light on the clinical presentation, imaging findings, pathogenesis, and treatment options for the rare condition of bilateral parietal bone thinning. Presentation: 6/3/2024

7686 A Case Of A 66-Year-Old Male With Systemic Macrocytosis Complicated By Osteoporosis

Abstract Disclosure: J.M. Gri: None. M. Hillhouse: None. P. madhavan: None. Background: Osteoporosis in men is underestimated and warrants investigation for secondary causes of osteoporosis. Systemic mastocytosis is a rare secondary cause of osteoporosis. Clinical Case: This is a 66-year-old male with a past medical history of severe persistent asthma, eczema, hypertension, GERD with esophagitis, basal cell carcinoma, and systemic mastocytosis (diagnosed in 2010). Family history was significant for lung cancer in both of his parents. Patient was first noted to have hyperpigmented skin lesions on his legs, trunk and upper extremities in the early 1990s. The spots were biopsied and he was diagnosed with urticaria pigmentosa in 1998. Due to persistent symptoms of facial flushing and soft stool, he was referred to Hematology and was started on antihistamines. He later underwent a bone marrow biopsy in 2010 which showed multifocal mast cell aggregates but normal trilineage hematopoiesis. He endorsed back pain shortly after his diagnosis and a DXA scan was completed. The DXA scan showed osteopenia of the spine T score of -1.8, BMD 0.999 mg/mm3 and normal bone density in bilateral hips. He had no history of fractures. He was started on alendronate and remained on the medication from 2012 to 2015. It was stopped due to intolerable symptoms of acid reflux and he required proton pump inhibitors. DXA scan in 2017 showed normal bone density of the hips and osteopenia of the lumbar spine (T score -1.2). DXA scan in 2022 showed a decrease in spine BMD by 6% (T score -1.8) from 2017 to 2022 but unchanged from 2010. Hip bone mineral density was normal but decreased by 10% since 2010 and by 6% since 2017. Labs obtained in May 2022 showed normal serum electrophoresis, normal urine calcium and creatinine ratio, calcium and vitamin D level and urine NTX of 41 nM BCE/mM (21-83) and bone specific alkaline phosphatase level of 31.5 U/L (15-41.3). After discussion with the patient, conservative management with calcium, vitamin D and exercise has been implemented along with close follow up. Should the patient’s bone turnover markers increase or fracture risk increase, additional antiresorptive therapy will be initiated. Conclusion: This case study highlights the importance of screening for osteoporosis in patients with systemic macrocytosis. As this patient was diagnosed with osteopenia at age 53, this case also emphasizes the importance of early screening in both women and men with this rare condition. Presentation: 6/3/2024

9342 Managing Osteoporosis In Patients With Phocomelia: Challenges And Strategies

Abstract Disclosure: M. Renzu: None. C. Hubers: None. V. Mehta: None. A.M. Qazi: None. A.M. Satei: None. D.K. Yerasuri: None. Introduction: Phocomelia, a rare congenital limb malformation, often results from disruptions in limb bud formation during embryonic stage, due to genetic mutations, teratogens, or environmental factors like thalidomide embryopathy. These disruptions pose unique challenges in bone health management, including an increased risk of osteoporosis.We present a case report of a 52-year-old patient with phocomelia who developed an early onset severe osteoporosis. This case stresses the need for specific measures and care to tackle bone health in individuals with congenital limb anomalies. Case Presentation: A 52-year-old white female with phocomelia, had absence of the left forearm and hand, as well as a transverse tibial deficiency with a prosthetic left lower leg since the age of 1. Osteoporosis was diagnosed after follow-up, with initial osteopenia noted at age 49. DEXA scan showed lumbar osteopenia, radial osteoporosis, and bilateral femoral neck osteopenia. FRAX score showed an 11.9% risk of osteoporotic fracture and 3.1% risk of a hip fracture.Risk factors to her osteoporosis included late menarche, early menopause due to hysterectomy, and a history of hormone replacement therapy without pregnancies. Also, chronic colitis and diarrhea caused malabsorption issues. Her left hip bone mineral density was disproportionately low due to chronic prosthesis use, necessitating close monitoring and treatment initiation with Denosumab, along with vitamin D3 and calcium supplementation.As of the latest follow-up, the patient is closely monitored, and improvement is noted in her condition. She has incorporated daily gym sessions into her routine, indicating proactive engagement in her well-being. Discussion: Managing osteoporosis in patients with phocomelia needs a personalized approach, considering the patient's unique anatomical challenges and the limitations of traditional osteoporosis management strategies. Bone tissue adapts its structure based on mechanical loading, with reduced loading in deformed limbs leading to increased resorption and elevated osteoporosis risk. Tailored treatment plans, including Denosumab, which is known as an effective pharmacological option for managing osteoporosis, complemented by dietary adjustments to enhance vitamin D and calcium intake. Physical therapy programs play a vital role in muscle strengthening and balance improvement, reducing fracture risk.Another challenge that patients with phocomelia face is barriers to accessing healthcare services, like limited specialized care providers, financial constraints, and transportation difficulties, leading to increased morbidity. Hence early screening and intervention are essential to prevent osteoporotic complications. Overall, a comprehensive approach to osteoporosis management in phocomelia patients is crucial for optimizing outcomes and enhancing quality of life. Presentation: 6/3/2024

7867 Treatment-Related Changes in Total Hip Bone Mineral Density and Fracture Risk Reduction for Drugs With Different Mechanisms of Action: The FNIH-ASBMR-SABRE Project

Abstract Disclosure: T. Vilaca: None. M.T. Schini: None. A.R. Thompson: None. E. Vittinghoff: None. L. Lui: None. S.K. Ewing: None. D.C. Bauer: None. D.M. Black: None. M. Bouxsein: None. R. Eastell: Consulting Fee; Self; Immunodiagnostic Systems, CL Bio, CureTeQ, Biocon, Takeda, UCB. Grant Recipient; Self; Alexion Pharmaceuticals, Inc., Osteolabs. Speaker; Self; Pharmacosmos, Alexion Pharmaceuticals, Inc., Amgen Inc, UCB. Introduction: To date, trials of new anti-osteoporosis therapies have used fractures as primary endpoints. In the FNIH-ASBMR-SABRE project, we posited that the treatment-related change in total hip BMD (THBMD) could be used as a surrogate endpoint for fractures in future clinical trials of new osteoporosis therapies. To demonstrate this, we compiled a large dataset of individual patient data (IPD) from randomized trials and showed a strong association between the change in THBMD at 24 months and reduction in fracture risk. To further explore the use of THBMD as a surrogate endpoint, here we examine whether the association is robust across drugs with different mechanisms of action. Methods: We used IDP (n&amp;gt;120,000 participants) from 22 randomized, placebo-controlled, double-blind trials of osteoporosis medications (17 anti-resorptive, 3 PTH analogs, 1 odanacatib, and 1 romosozumab). We calculated the treatment-related difference (active-placebo) in mean % change in THBMD at 12, 18, and 24 months for each trial. We determined the treatment-related fracture risk reductions for the entire follow-up period, using logistic regression for radiologic vertebral fractures and Cox regression for all clinical fractures (a combination of non-vertebral and clinical vertebral fractures). We used meta-regression to estimate the study-level association (r2) between treatment-related differences in THBMD changes and fracture risk reduction, including only the 17 trials of anti-resorptive drugs and then using the entire set of 22 trials. Since there were only 3 trials of anabolic drugs, we did not perform separate analyses for the anabolic trials. Results: The r2 values were similar between all trials and antiresorptive trials only for both fracture outcomes at all time points. Specifically, for vertebral fractures, the r2 was 0.59 vs 0.70 at 12 mo, 0.69 vs 0.74 at 18 mo, and 0.73 vs 0.78 at 24 mo for all trials vs anti-resorptive trials only. For all clinical fractures, the r2 was 0.46 vs 0.51 at 12 mo, 0.64 vs 0.60 at 18 mo, and 0.71 vs 0.65 at 24 mo for all trials vs anti-resorptive trials only. Conclusion: These results demonstrate that the associations between treatment-related changes in THBMD and fracture risk reductions are robust across anti-osteoporosis therapies with varying mechanisms of action. We conclude that the treatment-related difference in THBMD change would predict fracture reduction equally well for drugs with different mechanisms of action. Presentation: 6/2/2024

Effectiveness of RF ablation and cementoplasty in enhancing functional capacity in pelvic malignant bone metastases.

Pelvic and sacral bone metastases cause significant morbidity. The primary aim of the study is to thoroughly evaluate the increase in functional capacity resulting from combined RF ablation and cementoplasty surgery applied to malignant bone metastases of the pelvic bones. Twenty patients who underwent RF ablation and cementoplasty for malign pelvic bone and sacrum metastases between January 2014 and December 2021 were retrospectively identified. The inclusion criteria were having a life expectancy of more than 1month, being > 18years old, and having at least 1 month of follow-up. The Visual Anlogue Scale (VAS) pain, Karnofsky Performance Status (KP), and Musculoskelatal Tumor Society (MSTS) scores were calculated. VAS pain values decreased, and KP values increased postoperatively (p = 0.006 and p = 0,013). There was no statistically significant increase in MSTS (p > 0.05). The correlation relationships between lesion filling ratio and VAS pain, KP, and MSTS scores were not statistically significant (p > 0.05). Cement leakage was observed in 5 patients (25.0%), and no symptoms related to this leakage were observed. The pelvic region, given its close proximity to blood vessels, nerves, and joint areas, along with the distinct challenges associated with its surgery, requires separate evaluation. In studies evaluating applications in the isolated pelvic ring region, as in our study, functional gains have been most comprehensively assessed in this study, demonstrating that the procedure results in significant functional improvements.

MRI-based Zero Echo Time and Black Bone Pseudo-CT Compared with Whole-Body CT to Detect Osteolytic Lesions in Multiple Myeloma.

Background MRI is highly sensitive for assessing bone marrow involvement in multiple myeloma (MM) but does not enable detection of osteolysis. Purpose To assess the diagnostic accuracy, repeatability, and reproducibility of pseudo-CT MRI sequences (zero echo time [ZTE], gradient-echo black bone [BB]) in detecting osteolytic lesions in MM using whole-body CT as the reference standard. Materials and Methods In this prospective study, consecutive patients were enrolled in our academic hospital between June 2021 and December 2022. Inclusion criteria were newly diagnosed MM, monoclonal gammopathy of undetermined significance at high risk for MM, or suspicion of progressive MM. Participants underwent ZTE and BB sequences covering the lumbar spine, pelvis, and proximal femurs as part of 3-T whole-body MRI examinations, as well as clinically indicated fluorine 18 fluorodeoxyglucose PET/CT examination within 1 month that included optimized whole-body CT. Ten bone regions and two scores (categorical score = presence/absence of osteolytic lesion; semiquantitative score = osteolytic lesion count) were assessed by three radiologists (two experienced and one unfamiliar with pseudo-CT reading) on the ZTE, BB, and whole-body CT images. The accuracy, repeatability, and reproducibility of categorical scores (according to Gwet agreement coefficients AC1 and AC2) and differences in semiquantitative scores were assessed at the per-sequence, per-region, and per-patient levels. Results A total of 47 participants (mean age, 67 years ± 11 [SD]; 27 male) were included. In experienced readers, BB and ZTE had the same high accuracy (98%) in the per-patient analysis, while BB accuracy ranged 83%-100% and ZTE accuracy ranged 74%-94% in the per-region analysis. An increase of false-negative (FN) findings in the spine ranging from +17% up to +23%, according to the lumbar vertebra, was observed using ZTE (P < .013). Regardless of the region (except coxal bones), differences in the BB score minus the ZTE score were positively skewed (P < .021). Regardless of the sequence or region, repeatability was very good (AC1 ≥0.87 for all), while reproducibility was at least good (AC2 ≥0.63 for all). Conclusion Both MRI-based ZTE and BB pseudo-CT sequences of the lumbar spine, pelvis, and femurs demonstrated high diagnostic accuracy in detecting osteolytic lesions in MM. Compared with BB, the ZTE sequence yielded more FN findings in the spine. ClinicalTrials.gov Identifier: NCT05381077 Published under a CC BY 4.0 license. Supplemental material is available for this article.