Bilateral Femoral Fractures Research Articles

Cigarette Smoke Exposure Impairs Fracture Healing in a Rat Model: Preferential Impairment of Endochondral over Membranous Healing.

Cigarette smoking affects fracture repair, leading to delayed healing or nonunion. We sought to investigate if cigarette smoke differentially affects intramembranous and endochondral ossification in healing fractures, focusing on whether endochondral ossification is particularly impaired. This study utilized a bilateral femur fracture model in Sprague Dawley rats to examine the impact of cigarette smoke exposure on healing of femur fractures, treated with either a custom-locked intramedullary nail or compression plating to induce endochondral and membranous ossification, respectively. Animals were exposed to tobacco smoke 30 days before and after surgery, with evaluations including radiographs, histomorphometry, and microCT at 10 days, 1, 3, and 6-months post-operation, and biomechanical testing at 3, 6 months. Sixty-eight animals were randomized to control or exposure groups (two died perioperatively), and 89% of the femora achieved union when harvested at 3 and 6 months. Smoke exposure delayed cartilaginous callus formation and bone maturation in nailed fractures compared to plated fractures and controls in same animals. Plated fractures in exposed animals exhibited little cartilage callus and healed like control animals. At 3 months, plated fractures were stiffer and stronger than nailed fractures in both groups, but these differences vanished by 6 months. Plated fractures healed more rapidly and more completely than nailed fractures under both control and smoke-exposed conditions. Using compression plating instead of IM nailing for closed long bone fractures may lead to better outcomes in patients who smoke compared to current results with nailing.

7999 Tumor Induced Osteomalacia Caused By Glomangiopericytoma

Abstract Disclosure: N. Kabir: None. E. Campbell: None. S. Singh: None. Introduction: Tumor induced osteomalacia (TIO) is a rare paraneoplastic syndrome caused primarily by FGF-23 secreting tumors. Excessive production of FGF23 causes hypophosphatemia, decreased phosphate resorption in the gut, increased renal phosphate wasting, and decreased activation of Vitamin D. This leads to decreased bone density, bone pain, proximal muscle weakness, impaired gait, and recurrent fractures. Case Presentation: 44 year old male with a history of recurrent insufficiency fractures and weakness. At the time of evaluation, he reported fracture of tibial growth plate, sacral fracture, and metatarsal stress fracture. Other symptoms included bone pain, fatigue, muscle weakness, and intercostal muscle spasms with exertion. His pain was debilitating, requiring crutches to ambulate. Available labs at that time were significant for hypophosphatemia (1.3 mg/dL), elevated ALP (160 U/L), low 25OH-vitamin D (26 ng/mL), and normal calcium (8.7 mg/dL). Urine studies demonstrated phosphaturia (fractional excretion of phosphate, 62.4%). FGF23 level resulted at the upper limit of normal (210 RU/mL). Pending further evaluation, burosumab was started. Further work up included a 68Ga-PET-DOTATATE scan revealing a somatostatin receptor expressing soft tissue mass in the left sphenoid sinus and posterior left ethmoid sinus. The scan also demonstrated impending bilateral femur fractures, prior rib fractures, and sacral insufficiency fractures. Based on these findings, he was admitted to the hospital and underwent prophylactic, intramedullary nail fixation of his bilateral femur fractures. He underwent resection of skull base tumor with the final pathology revealing a sinonasal glomangiopericytoma. Immunohistochemical stain was positive for CD99 and cyclin D1, and focally positive for SMA, consistent with histopathologic diagnosis. Patient required prolonged inpatient rehabilitation to recover independent ambulation. Discussion: Sinonasal glomangiopericytoma (SNGP) is a mesenchymal tumor that accounts for <0.5% of all nasal and sinus tumors. TIO due to SNGP is extremely rare, with only a few cases reported since the 1990s. As seen with our patient, TIO from SNGP rarely presents with sinonasal symptoms, and can often be overlooked. Our patient hadb significant progression of disease and disability due to numerous delays in diagnosis and management. Definitive cure for TIO can be achieved with complete surgical resection of the tumor, but failure to diagnose in a timely manner can result in decline in quality of life. Our takeaway from this case is that providers should obtain FGF23 levels, especially in the setting of hypophosphatemia and phosphaturia, to complete the work up for osteomalacia. Presentation: 6/1/2024

Bilateral atypical femur fracture in a patient with breast cancer taking zoledronic acid and denosumab: a case report.

A 54-year-old woman developed stage IV breast cancer 8 years prior. Chemotherapy was administered, and she was started on zoledronic acid treatment for her bone metastases. Her chemotherapy regimen was then switched, owing to disease progression. Fifty-seven months after starting treatment with zoledronic acid, the patient suffered an atypical femoral fracture of her right femur, for which she underwent surgery. Twenty months later, she developed another atypical femoral fracture in her left femur and underwent intramedullary nail fixation. Zoledronic acid and denosumab use in patients with metastatic bone tumors caused by breast cancer should be done cautiously, considering atypical femoral fracture risk.

Trauma

The October 2024 Trauma Roundup360 looks at: Early versus delayed weightbearing following operatively treated ankle fracture (WAX): a non-inferiority, multicentre, randomized controlled trial; The effect of early weightbearing and later weightbearing rehabilitation interventions on outcomes after ankle fracture surgery; Is intramedullary nailing of femoral diaphyseal fractures in the lateral decubitus position as safe and effective as on a traction table?; Periprosthetic fractures of the hip: Back to the Future, Groundhog Day, and horses for courses; Two big bones, one big decision: when to fix bilateral femur fractures; Comparison of ankle fracture fixation using intramedullary fibular nailing versus plate fixation; Unclassified acetabular fractures: do they really exist?

Damage Control Orthopaedics Induced Less Trauma-Induced Coagulopathy than Early Total Care in a Porcine Polytrauma Model

Introduction: Coagulopathic disorders (CDs) complicate treatment in polytraumatised patients. Against this background, operative strategies for fracture management are controversial in this cohort. This study therefore investigated the effects of two established operative concepts, early total care (ETC) and damage control orthopaedics (DCO), on CD in a large-animal polytrauma (PT) model. Methods: Twenty-two animals (Sus scrofa domesticus) sustained PT involving blunt-chest trauma, liver laceration, bilateral femur fracture, and pressure-controlled haemorrhagic shock. After resuscitation, animals were allocated to ETC (n = 8), DCO (n = 8), or served as a non-traumatised control group (CG, n = 6). Animals were ventilated and monitored under ICU standards for 72 h. Blood samples were collected at baseline and post-trauma after 1.5, 2.5, 24, 48, and 72 h. Plasminogen activator inhibitor-1 (PAI-1) and thrombin-antithrombin (TAT) complex concentrations were determined by ELISA. Results: Compared to the CG, ETC and DCO subjects had significantly increased plasma concentrations of PAI-1 after 2.5 h (CG vs. ETC: p = 0.0050, CG vs. DCO: p = 0.0016). Furthermore, the ETC group showed significantly increased plasma PAI-1 concentrations after 24 h compared to the CG and DCO groups (CG vs. ETC: p = 0.0002, DCO vs. ETC: p = 0.0004). During the later clinical course, concentrations of TAT were significantly increased in the ETC group compared to the CG and DCO group after 72 h (CG vs. ETC: p = 0.0290, DCO vs. ETC: p = 0.0322). Conclusion: PT is strongly associated with CD in the early post-traumatic course. In comparison to DCO, ETC appeared to be negatively associated with CD. Future studies must investigate this impact, especially in those patients admitted with trauma-induced coagulopathy, to improve outcomes.

Three-dimensional assessment of subchondral arc and hip joint coverage angles in the asymptomatic young adult hip.

The primary objective of this study was to develop a custom algorithm to assess three-dimensional (3D) acetabular coverage of the femoral head based on surface models generated from computed tomography (CT) imaging. The secondary objective was to apply this algorithm to asymptomatic young adult hip joints to assess the regional 3D acetabular coverage variability and understand how these novel 3D metrics relate to traditional two-dimensional (2D) radiographic measurements of coverage. The algorithm developed automatically identifies the lateral- and medial-most edges of the acetabular lunate at one-degree intervals around the acetabular rim based on local radius of curvature. The acetabular edges and the center of a best-fit sphere to the femoral head are then used to compute the mean 3D subchondral arc angles and hip joint coverage angles in five acetabular octants. This algorithm was applied to hip models generated from pelvis/hip CT imaging or abdomen/pelvis CT angiograms of 50 patients between 17 and 25 years of age who had no history of congenital or developmental hip pathology, neuromuscular conditions, or bilateral pelvic and/or femoral fractures. Corresponding 2D acetabular coverage measures of lateral center edge angle (LCEA) and acetabular arc angle (AAA) were assessed on the patients' clinical or digitally reconstructed radiographs. The 3D subchondral arc angle in the superior region (58.0 [54.6-64.8] degrees) was significantly higher (p < 0.001) than all other acetabular subregions. The 3D hip joint coverage angle in the superior region (26.2 [20.7-28.5] degrees) was also significantly higher (p < 0.001) than all other acetabular subregions. 3D superior hip joint coverage angle demonstrated the strongest correlation with 2D LCEA (r = 0.649, p < 0.001), while 3D superior-anterior subchondral arc angle demonstrated the strongest correlation with 2D AAA (r = 0.718, p < 0.001). The 3D coverage metrics in the remaining acetabular regions did not strongly correlate with typical 2D radiographic measures. The discrepancy between standard 2D measures of radiographic acetabular coverage and actual 3D coverage identified on advanced imaging indicates potential discord between anatomic coverage and the standard clinical measures of coverage on 2D imaging. As 2D measurement of acetabular coverage is increasingly used to guide surgical decision-making to address acetabular deformities, this work would suggest that 3D measures of acetabular coverage may be important to help discriminate local coverage deficiencies, avoid inconsistencies resulting from differences in radiographic measurement techniques, and provide a better understanding of acetabular coverage in the hip joint, potentially altering surgical planning and guiding surgical technique.

Bilateral Femoral Neck Stress Fractures Due to Opioid Abuse-Induced Osteoporosis: Two Case Reports and Review of Literature

Bilateral Femoral Neck Stress Fractures Due to Opioid Abuse-Induced Osteoporosis: Two Case Reports and Review of Literature

Tenofovir Induced Bilateral Femoral Neck Stress Fracture

Case: A 47 year old male, came with history of bilateral hip pain ,insidious in onset gradually progressive, with difficulty in walking unassisted since 2 years. No history of fall/ trauma. Patient is known case of retroviral disease and on ART (TLE regimen ) since 2 years. Relevant radiographs were done and was diagnosed with bilateral neck of femur stress fracture (Tenofovir induced) associated with hypophosphatemia. ART regimen was changed to (Abacavir ,Lamivudine , Dolutegravir) . Patient on regular follow up every 2 months with serial radiographs. . On 6 months follow up patient is symptomatically improved with healing bilateral neck of femur stress fracture.

Delayed femoral artery injury caused by heterotopic ossification: a rare case report and review of the literature

BackgroundArterial injury caused by heterotopic ossification (HO) following fractures is rarely reported, yet it can have catastrophic consequences. This case report presents a unique instance of femoral artery injury and hematoma organization, occurring a decade after intramedullary nail fixation for a femoral shaft fracture complicated by HO.Case presentationA 56-year-old male presented with right femoral artery injury and organized hematoma, a decade after suffering bilateral femoral shaft fractures with mild head injury in a traffic accident. He had received intramedullary nailing for the right femoral shaft fracture and plate fixation for the left side in a local hospital. Physical examination revealed two firm, palpable masses with clear boundaries, limited mobility, and no tenderness. Peripheral arterial pulses were intact. Radiography demonstrated satisfactory fracture healing, while a continuous high-density shadow was evident along the inner and posterior aspect of the right thigh. Computed tomography angiography identified a large mixed-density mass (16.8 × 14.8 × 20.7 cm) on the right thigh’s medial side, featuring central calcification and multiple internal calcifications. The right deep femoral artery coursed within this mass, with a smaller lesion noted on the posterior thigh. Surgical consultation with a vascular surgeon led to planned intervention. The smaller mass was completely excised, but the larger one partially, as it encased the femoral artery. The inability to remove all HO was due to excessive bleeding. Postoperatively, the patient experienced no complications, and one-year follow-up revealed a favorable recovery with restoration of full right lower limb mobility.ConclusionThis case underscores the potential gravity of vascular injury associated with heterotopic ossification. Surgeons should remain vigilant regarding the risk of vascular injury during HO excision.

Standard or Fin SIGN® nail? which option is better for the treatment of femoral fractures in low and middle-income countries?

PurposeFemoral fractures are common in low and middle-income countries (LMIC), predominantly caused by high-energy trauma. The surgical implant generation network (SIGN®) program offers two different intramedullary nails in LMIC which are designed to be used without image intensifier free of charge for the patients: the SIGN standard nail (SSN®) and the SIGN Fin nail (SFN®). This study aimed to compare the results of the SSN® and the SFN® for the treatment of middle and distal shaft femoral fractures through a retrograde approach.Material and MethodsThis was a retrospective, descriptive, and non-experimental study including all consecutive patients who underwent surgical management of middle or distal shaft femoral fracture between January 2017 and May 2022 in an NGO hospital located in Freetown, Sierra Leone. The duration of surgery, type of reduction, complications like screw loosening, implant migration, anterior knee pain and non-union rate at six months of follow up were evaluated.ResultsA total of 122 patients were included in the study. Group A: 60 patients were managed with SSN® and Group B: 62 patients with SFN®. The mean operative time was 104 min with SSN® and 78 with SFN® (p < 0.001). Open reduction of the fracture was necessary in ten (16.7%) patients with SSN® and 12 (19.4%) patients treated with SFN® (p = 0.69). Non-union was observed in one (1.7%) patient with SSN® and two (3.2%) patients with SFN® (p = 0.57).ConclusionsBoth options seem equally effective in treating midshaft and distal femoral shaft fractures. The SFN® reduces the surgical time, due to this fact, in polytraumatized patients, patients with bilateral femur fracture or patients with ipsilateral tibia fracture, it can be considered as the best option to be used. There was no statistical difference in the complications presented by the two groups.

Two big bones, one big decision: When to fix bilateral femur fractures

PurposeFor polytrauma patients with bilateral femoral shaft fractures (BFSF), there is currently no consensus on the optimal timing of surgery. This study assesses the impact of early (≤ 24 h) versus delayed (>24 h) definitive fixation on clinical outcomes, especially focusing on concomitant versus staged repair. We hypothesized that early definitive fixation leads to lower mortality and morbidity rates. MethodsThe 2017–2020 Trauma Quality Improvement Program was used to identify patients aged ≥16 years with BFSF who underwent definitive fixation. Early definitive fixation (EDF) was defined as fixation of both femoral shaft fractures within 24 h, delayed definitive fixation (DDF) as fixation of both fractures after 24 h, and early staged fixation (ESF) as fixation of one femur within 24 h and the other femur after 24 h. Propensity score matching and multilevel mixed effects regression models were used to compare groups. Results1,118 patients were included, of which 62.8% underwent EDF. Following propensity score matching, 279 balanced pairs were formed. EDF was associated with decreased overall morbidity (12.9% vs 22.6%, p = 0.003), lower rate of deep venous thrombosis (2.2% vs 6.5%, p = 0.012), a shorter ICU LOS (5 vs 7 days, p < 0.001) and a shorter hospital LOS (10 vs 15 days, p < 0.001). When compared to DDF, early staged fixation (ESF) was associated with lower rates of ventilator acquired pneumonia (0.0% vs 4.9%, p = 0.007), but a longer ICU LOS (8 vs 6 days, p = 0.004). Using regression analysis, every 24-hour delay to definitive fixation increased the odds of developing complications by 1.05, postoperative LOS by 10 h and total hospital LOS by 27 h. ConclusionEarly definitive fixation (≤ 24 h) is preferred over delayed definitive fixation (>24 h) for patients with bilateral femur shaft fractures when accounting for age, sex, injury characteristics, additional fractures and interventions, and hospital level. Although mortality does not differ, overall morbidity and deep venous thrombosis rates, and length of hospital and intensive care unit stay are significantly lower. When early definitive fixation is not possible, early staged repair seems preferable over delayed definitive fixation.

Pulmonary miRNA expression after polytrauma depends on the surgical invasiveness and displays an anti-inflammatory pattern by the combined inhibition of C5 and CD14.

Respiratory failure can be a severe complication after polytrauma. Extensive systemic inflammation due to surgical interventions, as well as exacerbated post-traumatic immune responses influence the occurrence and progression of respiratory failure. This study investigated the effect of different surgical treatment modalities as well as combined inhibition of the complement component C5 and the toll-like receptor molecule CD14 (C5/CD14 inhibition) on the pulmonary microRNA (miRNA) signature after polytrauma, using a translational porcine polytrauma model. After induction of general anesthesia, animals were subjected to polytrauma, consisting of blunt chest trauma, bilateral femur fractures, hemorrhagic shock, and liver laceration. One sham group (n=6) and three treatment groups were defined; Early Total Care (ETC, n=8), Damage Control Orthopedics (DCO, n=8), and ETC + C5/CD14 inhibition (n=4). Animals were medically and operatively stabilized, and treated in an ICU setting for 72 h. Lung tissue was sampled, miRNAs were isolated, transcribed, and pooled for qPCR array analyses, followed by validation in the individual animal population. Lastly, mRNA target prediction was performed followed by functional enrichment analyses. The miRNA arrays identified six significantly deregulated miRNAs in lung tissue. In the DCO group, miR-129, miR-192, miR-194, miR-382, and miR-503 were significantly upregulated compared to the ETC group. The miRNA expression profiles in the ETC + C5/CD14 inhibition group approximated those of the DCO group. Bioinformatic analysis revealed mRNA targets and signaling pathways related to alveolar edema, pulmonary fibrosis, inflammation response, and leukocytes recruitment. Collectively, the DCO group, as well as the ETC + C5/CD14 inhibition group, revealed more anti-inflammatory and regenerative miRNA expression profiles. This study showed that reduced surgical invasiveness and combining ETC with C5/CD14 inhibition can contribute to the reduction of pulmonary complications.

TREATMENT OF PEDIATRIC FEMUR FRACTURES WITH FLEXIBLE STAINLESS STEEL INTRAMEDULLARY NAIL.

To identify the characteristics of patients and femur fractures treated with a stainless steel intramedullary nail (ESIN) in children under 15 years of age. Know the results of using the ESIN of related steel in the service. Retrospective study with review of hospital records and organization of data in spreadsheets. 24 cases were identified, 17 male cases and 7 female cases. A minimum age of 4 years and a maximum of 11 years were observed (average of 7 years). The 3 most common trauma mechanisms were being run over (n:8, 33%) and falling from a height (n:8, 3%). The most common location of the fractures was in the mid-diaphyseal region (n: 20, 88%), only one case presented a bilateral femur fracture. The most common associated trauma was traumatic brain injury. The observation period observed several months between 2 and 5. With regard to complications, 3 cases were observed (12.5%) being bursitis, vicious construction and loss of reduction. Steel HIF shows similar good results. As the study includes the retrospective profile, the absence of a group and the small sample size. Level of Evidence IV, Case series.

Fat embolism syndrome in Duchenne muscular dystrophy: Report on a novel case and systematic literature review

We report a non-ambulatory 13-year-old boy with Duchenne muscular dystrophy who experienced severe acute respiratory distress syndrome and cerebral fat embolism following elective soft tissue surgery. Post-surgery radiological examination revealed bilateral femoral fractures and marked osteopenia that were believed to have caused disseminated pulmonary and cerebral fat embolism. The patient had never been on glucocorticoid treatment. Five months post-surgery, he remained in a state of minimal consciousness.A literature review was performed and eleven publications included, providing case reports of a total number of 23 patients with Duchenne muscular dystrophy with fat embolism syndrome. The most common causes were falls from the wheelchair that predominantly resulted in femoral fractures. Median age at the event was around 14 years. Seven patients succumbed to complications of fat embolism. No event was described in the context of surgery. We want to raise awareness that spontaneous unnoticed fractures may occur especially in adolescents with DMD from traumatic injury of large bones and also during elective surgery with a high risk of causing fat embolism with severe sequelae.

Bilateral atypical femoral fracture in osteoporotic patient treated with bisphosphonates

Bilateral atypical femoral fracture in osteoporotic patient treated with bisphosphonates

Bilateral atypical femoral fracture in osteoporotic patient treated with bisphosphonates

Bilateral atypical femoral fracture in osteoporotic patient treated with bisphosphonates

Circulating miRNA expression in extracellular vesicles is associated with specific injuries after multiple trauma and surgical invasiveness.

Two trauma treatment principles are Early Total Care (ETC), and Damage Control Orthopedics (DCO). Cellular mechanisms that underlie the connection between treatment type, its systemic effects, and tissue regeneration are not fully known. Therefore, this study aimed to: 1) profile microRNA (miRNA) expression in plasma derived Extracellular Vesicles (EVs) from a porcine multiple trauma model at different timepoints, comparing two surgical treatments; and 2) determine and validate the miRNA's messengerRNA (mRNA) targets. The porcine multiple trauma model consisted of blunt chest trauma, liver laceration, bilateral femur fractures, and controlled haemorrhagic shock. Two treatment groups were defined, ETC (n=8), and DCO (n=8). Animals were monitored under Intensive Care Unit-standards, blood was sampled at 1.5, 2.5, 24, and 72 hours after trauma, and EVs were harvested from plasma. MiRNAs were analysed using quantitative Polymerase Chain Reaction arrays. MRNA targets were identified in silico and validated in vivo in lung and liver tissue. The arrays showed distinct treatment specific miRNA expression patterns throughout all timepoints, and miRNAs related to the multiple trauma and its individual injuries. EV-packed miRNA expression in the ETC group was more pro-inflammatory, indicating potentially decreased tissue regenerative capacities in the acute post-traumatic phase. In silico target prediction revealed several overlapping mRNA targets among the identified miRNAs, related to inflammation, (pulmonary) fibrosis, and Wnt-signalling. These were, among others, A Disintegrin and Metalloproteinase domain-containing protein 10, Collagen Type 1 Alpha 1 Chain, Catenin Beta Interacting Protein 1, and Signal Transducers and Activators of Transcription 3. Validation of these mRNA targets in the lung showed significant, treatment specific deregulations which matched the expression of their upstream miRNAs. No significant mRNA deregulations were observed in the liver. This study showed treatment specific, EV-packed miRNA expression patterns after trauma that correlated with mRNA expressions in the lungs, target organs over distance. A systemic response to the increased surgical trauma in the ETC group was identified, with various miRNAs associated with injuries from the trauma model, and involved in (systemic) inflammation, tissue regeneration. EV-transported miRNAs demonstrated a clear role in multiple trauma, warranting further research into tissue-tissue talk and therapeutic applications of EVs after trauma.

SAT440 DRESS/DHIS-associated Thyroiditis And Hypophysitis

Abstract Disclosure: I.R. Ranasinghe: None. M.S. Elston: None. V. Boyle: None. Introduction: Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DRESS/DIHS) is a severe life-threatening adverse reaction to specific drugs, including cephalosporin antibiotics (1). It is characterised by rash, fever, eosinophilia, lymphadenopathy, and inflammation of internal organs. Endocrine complications in the form of thyroid disease and Type 1 Diabetes have been reported following DRESS/DIHS (2). We report a case of thyroiditis and hypophysitis following cephalosporin-associated DRESS/DIHS. Case: A 21-year-old male farmer suffered a tractor crash accident resulting in hospitalization for bilateral compound distal femur fractures. He had no past medical history of note. One month later, he developed a maculopapular rash involving his limbs, mouth ulcers, fever, liver function derangement and eosinophilia. Punch biopsy was consistent with DRESS/DHIS. A 2- week tapering course of prednisone was initiated at 40mg daily in conjunction with a topical corticosteroid for 9 days with resolution of rash. Review of medication charts identified the most likely causative agent as cefazolin. An Endocrine consult was requested a month later due to new hypercalcemia. Investigations revealed new onset thyrotoxicosis and a decreasing morning cortisol over the following week despite having stopped all steroids one month earlier, normal ACTH, mildly elevated prolactin and secondary hypogonadism. Short Synacthen test showed suboptimal response. TRAb were negative and technetium thyroid scanning demonstrated a thyroiditis. MRI pituitary was unremarkable. He was commenced on hydrocortisone replacement for symptomatic cortisol deficiency. Biochemical abnormalities gradually normalized and his hydrocortisone ceased with symptomatic resolution. Endocrine involvement, particularly pancreas and thyroid has previously been reported in cases of DHIS/DRESS (3) (4). In this case, DHIS/DRESS-associated hypophysitis with thyroiditis may explain the clinical findings of pituitary dysfunction affecting multiple pituitary axes and the gradual recovery to normal pituitary function.

THU439 Baby's Coming, Break A Leg! A Case Of Transient Osteoporosis Of The Hip

Abstract Disclosure: A. Khan: None. A. Syeda: None. H.B. Aftab: None. Introduction: Pregnancy-associated osteoporosis (PAO) is a rare condition presenting as fragility fractures usually in the latter part of pregnancy or immediate postpartum period. Vertebral fractures are more commonly reported but femoral fractures have also been described in the literature as a distinct entity: transient osteoporosis of the hip (TOH). We present a case of bilateral (B/L) femoral fractures in a woman during pregnancy and in the postpartum period. Case: A 31-year-old, gravida 1 female developed left leg pain at 26 weeks of gestation. The pain radiated from her left lower back to her left knee. It was severe in intensity resulting in her walking with crutches. Subsequent MRI of the left hip showed subchondral insufficiency fracture of the femoral head with prominent bone marrow edema extending from the head into the femoral neck. She was managed conservatively with non-weight bearing status and oral analgesics. She had an uncomplicated vaginal delivery at 39 weeks of gestation. During the first postpartum week she developed right hip pain. MRI of right hip revealed nondisplaced right femoral head subchondral insufficiency fracture with associated effusion and synovitis. She recovered within the next 3 months with resolution of her pain with conservative management. Other than limited calcium intake in childhood, there were no other identifiable risk factors for osteoporosis. Bone density scan revealed normal Z-scores at the lumbar spine and non-dominant wrist. The hips were not evaluated. Workup for secondary causes of osteoporosis was unremarkable including normal serum calcium, PTH, phosphorus, magnesium, SPEP, tissue transglutaminase antibodies, estradiol, LH, FSH, prolactin levels. However, 24-hour urine calcium level was low at 11 (35-250) mg/24hr. Elevated levels of bone specific alkaline phosphatase and urine N-telopeptide (NTX) were noted at 19.9 (5.3-19.5) mcg/L and 110 (4-64) nM BCE/mM creatinine, respectively. Patient was continued on vitamin D and calcium supplements. She breastfed for the initial 2 months but was advised to stop. At her most recent follow up visit 4 months postpartum patient was doing well. Discussion: TOH is a rare entity, and presentation as B/L femoral fractures is exceedingly rare. During pregnancy and lactation, the skeletal system undergoes bone loss to compensate for the calcium demand of the fetal skeletal system. In TOH, venous stasis from the gravid uterus resulting in bone marrow edema is the proposed mechanism in addition to pregnancy associated bone loss. In our patient, a low 24-hr urine calcium could suggest low calcium intake which could have contributed to the fracture as well. While recurrence of PAO has been described, no recurrence of TOH has been reported in subsequent pregnancies. Our case highlights the importance of keeping this rare entity on the differential in pregnant women presenting with back or hip pain. Presentation: Thursday, June 15, 2023

FRI684 So Strong Yet So Fragile: Bilateral Periprosthetic Fractures On Denosumab

Abstract Disclosure: A. Syeda: None. F.S. Mirza: None. Background: Denosumab (DN) is a potent antiresorptive and has been associated rarely with atypical femoral fractures. We hereby report the first case of simultaneous bilateral femoral periprosthetic fractures (PPF) while on DN therapy (DNT). Clinical Case: A 78-year-old female with severe osteoporosis on DNT presented in January 2023 with bilateral femoral PPF after a mechanical fall whereby she tripped and landed on her knees. The patient had initially presented to us in late 2012. Treatment history included alendronate (ALN) for 5 years, on drug holiday since 2010. She underwent bilateral knee replacement surgeries in 2012 and DNT was started in 2013 after initial evaluation. She also had primary biliary cirrhosis, and although bone density (BD) improved on DNT, she exhibited escape from DN mediated suppression of bone resorption possibly related to the liver disease that was previously reported (1). DNT was stopped 5 years later when spine BD improved to osteopenic range and ALN 70 mg weekly was started. 1 year later, bone resorption markers were still elevated and zoledronic acid was substituted for ALN. She fell and had a pubic ramus fracture 11 months later. BD showed a 6% decrease for mean total hip and baseline forearm BD showed T-score of -3.7 on the right. DNT was restarted in December 2020 and continued every 6 months. Her health continued to deteriorate over next two years, with increase in LFTS, new anemia and thrombocytopenia due to a combination of myelodysplastic syndrome and splenomegaly. She also needed transcatheter aortic valve replacement for worsening CHF. She tripped and fell in January 2023. X-ray showed acute supracondylar bilateral PPF with comminution. She was high risk for anesthesia and anticoagulation was withheld due to a history of thrombocytopenia and gastrointestinal bleeding. Prior to the anticipated orthopaedic procedure, the patient developed severe hypotension and a rapid drop in hematocrit due to hemorrhagic shock. The family had requested DNR due to the multitude of medical issues. Conclusion: Occasional PPF have been reported in the setting of DNT, which may reflect the severity of osteoporosis. Altered stress distribution and decreased tensile strength of the bone secondary to screw/pin placement are thought to contribute to PPF, although the occurrence of PPF as an unusual presentation of an AFF cannot be excluded. Contribution of other comorbidities to poor bone quality may also have contributed to the bilateral PPF with poor outcome in our patient. 1. Vedere, T.R. and Mirza, F.S., 2017, April. Escape from Denosumab Mediated Suppression of Bone Resorption in Primary Biliary Cirrhosis. In 99th Annual Meeting of the Endocrine Society. Endocrine Society. Presentation: Friday, June 16, 2023