Bone Deficits Research Articles

Changes in peripheral quantitative computed tomography measured bone density, size and strength in Zimbabwean children with and without HIV over one year: a cohort study.

Understanding bone accrual in adolescents may inform approaches to improve skeletal health and reduce adult fracture risk. We investigated the effect of HIV on bone mineral accrual assessed by peripheral Quantitative Computed tomography (pQCT). Children with HIV (CWH) on ART for ≥2years, and children without HIV (CWOH), aged 8-16years (n = 609), had tibial pQCT scans at 0 and 12months. Linear regression estimated sex stratified differences in change (∆) and mean pQCT bone density (trabecular and cortical), size (total cross-sectional area [CSA]) and strength (SSI) between CWH and CWOH, adjusting for socio-economic status (SES) and orphanhood and incorporating an interaction term for baseline pubertal status (Tanner 1-2[pre/early] vs 3-5[mid/late]). Structural equation modelling tested whether baseline height-for-age-Z-scores (HAZ) mediate the effect of HIV on ∆bone outcomes. CWH were more likely than CWOH to be orphans (44% vs 7%), of lower SES (43% vs 27%) and be stunted (30% vs 8%); but similar in age. At baseline and follow up, CWH had lower trabecular density, CSA and SSI than CWOH. After adjustment, bone density and strength increased similarly in CWH and CWOH. CWH in mid/late puberty at baseline had greater 12months increases in CSA than CWOH, particularly males (mean difference [31.3(95%CI:-3.1, 65.6) mm2 in mid/late puberty vs. -2.04(-23.8, 19.7) mm2 in pre/early puberty; interaction P-value = 0.013]. HAZ mediated the effect of HIV on ∆bone outcomes only in females as follows: indirect pathways from HIV to ∆trabecular density [-1.85(-3.5, -0.2) mg/cm3], ∆cortical density [-2.01(-3.9, -0.01) mg/cm3], ∆CSA [-2.59(-4.7, -0.5) mm] and ∆SSI [-18.36(-29.6, -7.2) mm3]. In conclusion, CWH show bone deficits at follow up. Investigations of bone mineral accrual earlier in life and post-puberty to peak bone mass are needed.

5120 Contribution Of Proximal Femur Geometry And Bone Density Distribution To Hip Fragility In Adults ≥ 50yrs With Longstanding Type 1 Diabetes

Abstract Disclosure: F. Johannesdottir: None. C. D’Mello: None. A.B. Murthy: None. B. Zahedi: None. K. Engelke: None. M.L. Bouxsein: None. E.W. Yu: Grant Recipient; Self; Amgen Inc. Introduction: Adults with type 1 diabetes (T1D) have a 6-fold increased risk of hip fracture, which is explained only in part by lower areal bone mineral density (aBMD) by DXA. We hypothesize that femoral geometry and regional bone deficits at the proximal femur contribute to higher hip fracture risk in older adults with T1D. Further, we determine the influence of age at T1D diagnosis on femoral bone density and structure. Methods: We enrolled 97 individuals with T1D and 53 non-diabetic controls (CON) as part of the T1D Bone Health Connection (BEACON) Study, an ongoing prospective study of adults aged ≥50 years. We obtained computed tomography (CT) scans of the proximal femur (in-plane pixel size 0.98x0.98 mm, 1.25 mm slice thickness) to measure total (Tt), trabecular (Tb) and cortical (Ct) volumetric BMD (vBMD); and volume (Vol) and Ct thickness (Th) in several regions, including total hip, femoral neck (FN), trochanter (TR) and intertrochanter (IT) (Medical Image Analysis Framework, University of Erlangen, Germany). We also assessed total hip and FN aBMD by DXA. We employed ANCOVA models to compare bone outcomes between T1D and controls with adjustment for age, height, and weight, stratified by sex. When comparing bone outcomes within T1D, we adjusted for age, height, weight, and sex. Differences are reported as % difference between the least-square means for the groups. Results: The average age of participants was 64±7 yrs, and similar between T1D and CON (p=0.21). Male T1D were shorter than male CON (173 cm vs 176 cm, p=0.05), but with similar weight (p=0.73). Female T1D were heavier than female CON (71 kg vs 64 kg, p=0.03). The T1D cohort included 50 men and 47 women with mean diabetes duration of 46±10 yrs, mean A1c 7.1±1.0%, and median age at onset 17 yrs (IQR:10-25). Among T1D, 31 (52% female) were diagnosed ≤ age 12. Among men, total hip and FN aBMD did not differ by group, but T1D had smaller FN Tt.Vol (9%) and FN width (8%) (p<0.05 for all). In contrast, there were no differences between T1D and CON in the female cohort, neither by DXA nor CT (p≥0.13). Of note, T1D men appeared to have more poorly controlled diabetes than women (29% of men vs 11% women had A1c ≥8%, p=0.03). Within T1D, those who were diagnosed ≤ age 12 had lower Tb.vBMD (16-18%) at the total hip, TR and IT regions (p<0.05) and tended to have lower Tb.vBMD (16%, p=0.06) at the neck compared to those diagnosed at a later age, but no differences in DXA aBMD (p>0.31). Conclusion: In sum, older men, but not women, with T1D showed some deficits in bone structure at the proximal femur. Adults with T1D who were diagnosed ≤ age 12 had trabecular bone deficits within the proximal femur. Additional studies are needed to identify mechanisms underlying the high hip fracture risk in T1D. Presentation: 6/1/2024

Passive bicycle training stimulates epiphyseal bone formation and restores bone integrity independent of locomotor recovery in a rat spinal cord injury model.

It is unknown whether activity-based physical therapy (ABPT) modalities that mobilize the paralyzed limbs improve bone integrity at the highly fracture-prone epiphyseal regions of the distal femur and proximal tibia following severe spinal cord injury (SCI). In this study, 4-mo-old skeletally mature littermate-matched male Sprague-Dawley rats received either SHAM surgery or severe contusion SCI. At 1 wk postsurgery, SCI rats were stratified to undergo no-ABPT, two 20-min bouts/day of quadrupedal bodyweight-supported treadmill training (qBWSTT), or hindlimb passive isokinetic bicycle (cycle) training, 5 days/wk for another 3 wk. We assessed locomotor recovery and plantar flexor muscle mass, tracked cancellous and cortical bone microstructure at the distal femoral and proximal tibial epiphyses using in vivo microcomputed tomography (microCT), and evaluated bone turnover at the tibial epiphysis with histomorphometry. All SCI animals displayed persistent hindlimb paralysis and pervasive muscle atrophy. Over the initial 2 wk, which included 1 wk of no exercise and 1 wk of ABPT acclimation, a similar magnitude of bone loss developed in all SCI groups. Thereafter, cancellous bone loss and cortical bone decrements increased in the SCI no-ABPT group. qBWSTT attenuated this trabecular bone loss but did not prevent the ongoing cortical bone deficits. In comparison, twice-daily cycle training increased the number and activity of osteoblasts versus other SCI groups and restored all bone microstructural parameters to SHAM levels at both epiphyseal sites. These data indicate that a novel passive isokinetic cycle training regimen reversed cancellous and cortical bone deterioration at key epiphyseal sites after experimental SCI via osteoblast-mediated bone anabolic mechanisms, independent of locomotor recovery or increased muscle mass.NEW & NOTEWORTHY This study was the first to assess how quadrupedal bodyweight-supported treadmill training or passive isokinetic bicycle (cycle) training impacts bone recovery at the distal femoral and proximal tibial epiphyses in a rat model of severe contusion spinal cord injury. Our results demonstrate that passive isokinetic cycle training completely restored cancellous and cortical bone microstructural parameters at these sites via osteoblast-mediated bone anabolic actions, independent of locomotor recovery or increased plantar flexor muscle mass.

Microvascular disease and early diabetes onset are associated with deficits in femoral neck bone density and structure among older adults with longstanding type 1 diabetes.

Adults with type 1 diabetes (T1D) have increased hip fracture risk, yet no studies have assessed volumetric bone density or structure at the hip in older adults with T1D. Here, we used previously collected 3D CT scans of the proximal femur from older adults with longstanding T1D and non-diabetic controls to identify bone deficits that may contribute to hip fracture in T1D. In this retrospective cohort study, we identified 101 adults with T1D and 181 age-, sex-, and race-matched non-diabetic controls (CON) who received abdominal or pelvis CT exams from 2010 to 2020. Among adults with T1D, 33 (33%) had mild-to-moderate nephropathy, 61 (60%) had neuropathy, and 71 (70%) had retinopathy. Within the whole cohort, adults with T1D tended to have lower FN density, though differences did not reach statistical significance. The subset of the T1D group who were diagnosed before age 15 had lower total BMC (-14%, TtBMC), cortical BMC (-19.5%, CtBMC), and smaller Ct cross-sectional area (-12.6, CtCSA) than their matched controls (p<.05 for all). Individuals with T1D who were diagnosed at a later age did not differ from controls in any bone outcome (p>.21). Furthermore, adults with T1D and nephropathy had lower FN aBMD (-10.6%), TtBMC (-17%), CtBMC (-24%), and smaller CtCSA (-15.4%) compared to matched controls (p<.05 for all). Adults with T1D and neuropathy had cortical bone deficits (8.4%-12%, p<.04). In summary, among older adults with T1D, those who were diagnosed before the age of 15yr, as well as those with nephropathy and neuropathy had unfavorable bone outcomes at the FN, which may contribute to the high risk of hip fractures among patients with T1D. These novel observations highlight the longstanding detrimental impact of T1D when present during bone accrual and skeletal fragility as an additional complication of microvascular disease in individuals with T1D.

Serum Amyloid P Secreted by Bone Marrow Adipocytes Drives Skeletal Amyloidosis.

The accumulation of amyloid fibrils has been identified in tissues outside the brain, yet little is understood about the formation of extracerebral amyloidosis and its impact on the aging process of these organs. Here, we demonstrate that both transgenic mice modeling Alzheimer's disease (AD) and naturally aging mice exhibit accumulated senescent bone marrow adipocytes (BMAds), accompanied by amyloid deposits surrounding the BMAds. Senescent BMAds acquire a secretory phenotype, resulting in a marked increase in the secretion of serum amyloid P component (SAP), also known as pentraxin 2 (PTX2). SAP/PTX2 colocalizes with amyloid deposits around senescent BMAds in vivo and is sufficient to promote the formation of insoluble amyloid deposits from soluble Aβ peptides in in vitro and ex vivo 3D BMAd-based culture experiments. Additionally, Combined treatment with SAP/PTX2 and Aβ peptides promotes osteoclastogenesis but inhibits osteoblastogenesis of the precursor cells. Transplantation of senescent BMAds into the bone marrow cavity of healthy young mice is sufficient to induce bone loss. Finally, pharmacological depletion of SAP/PTX2 from aged mice abolishes bone marrow amyloid deposition and effectively rescues the low bone mass phenotype. Thus, senescent BMAds, through the secretion of SAP/PTX2, contribute to the age-associated development of skeletal amyloidosis and resultant bone deficits.

Bone and muscle differences in children and adolescents with type 1 diabetes: The mediating role of physical activity

Children with type 1 diabetes (T1D) experience an increased risk of fracture, which may be related to altered bone development. We aimed to assess differences in bone, muscle and physical activity (PA), and explore if better muscle and PA measures would mitigate bone differences between children and adolescents with T1D and typically developing peers (TDP). We matched 56 children and adolescents with T1D (mean age 11.9 yrs) and 56 TDP (11.5 yrs) by sex and maturity from 171 participants with T1D and 66 TDP (6-17 yrs). We assessed the distal radius and tibia with high-resolution peripheral quantitative computed tomography (HR-pQCT), and the radius and tibia shaft bone and muscle with pQCT. We also measured muscle function from force-related measures in neuromuscular performance tests (push-up, grip test, countermovement and long jump). We compared PA based on questionnaire scores and accelerometers between groups. Bone, muscle, and neuromuscular performance measures were compared using MANOVA. We used mediation to explore the role of PA and muscle in bone differences. Children and adolescents with T1D had 6–10 % lower trabecular density, bone volume fraction, thickness and number at both distal radius and tibia, and 11 % higher trabecular separation at the distal radius than TDP. They also had 3–16 % higher cortical and tissue mineral density, and cortical thickness at the distal radius, 5–7 % higher cortical density and 1–3 % higher muscle density at both shaft sites compared to TDP. PA mediated the between-group difference in trabecular number (indirect effect −0.04) at the distal radius. Children and adolescents with T1D had lower trabecular bone density and deficits in trabecular micro-architecture, but higher cortical bone density and thickness at the radius and tibia compared to TDP. They engaged in less PA but had comparable muscle measures to those of TDP. PA participation may assist in mitigating deficit in trabecular number observed in children and adolescents with T1D.

Risk Factors for Bone Microarchitecture Impairments in Older Men with Type 2 Diabetes - The MrOS Study.

Impaired bone microarchitecture, assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT), may contribute to bone fragility in type 2 diabetes (T2DM) but data on men are lacking. To investigate the association between T2DM and HR-pQCT parameters in older men. HR-pQCT scans were acquired on 1794 participants in the Osteoporotic Fractures in Men (MrOS) study. T2DM was ascertained by self-report or medication use. Linear regression models, adjusted for age, race, BMI, limb length, clinic site, and oral corticosteroid use, were used to compare HR-pQCT parameters by diabetes status. Among 1777 men, 290 had T2DM (mean age 84.4 years). T2DM men had smaller total cross-sectional area (Tt.AR) at the distal tibia (p=0.028) and diaphyseal tibia (p=0.025), and smaller cortical area at the distal (p= 0.009) and diaphyseal tibia (p= 0.023). Trabecular indices and cortical porosity were similar between T2DM and non-T2DM. Among men with T2DM, in a model including HbA1c, diabetes duration, and insulin use, diabetes duration ≥ 10 years, compared with <10 years, was significantly associated with higher cortical porosity but with higher trabecular thickness at the distal radius. Insulin use was significantly associated with lower cortical area and thickness at the distal radius and diaphyseal tibia and lower failure load at all three scan sites. Lower cortical area, cortical thickness, total BMD, cortical BMD, and failure load of the distal sites were associated with increased risk of incident non-vertebral fracture in T2DM. Older men with T2DM have smaller bone size compared to non-T2DM, which may contribute to diabetic skeletal fragility. Longer diabetes duration was associated with higher cortical porosity and insulin use with cortical bone deficits and lower failure load.

Accuracy of patient-specific instrumentation for implant positioning in custom-made total ankle arthroplasty.

This retrospective radiological analysis aimed to assess the accuracy of implant positioning in patients with ankle arthritis undergoing custom-made total ankle arthroplasty (TAA) with patient-specific instrumentation (PSI) compared with preoperative planning. Patients who underwent custom-made TAA with PSI from January 2018 to March 2023 were retrospectively evaluated, focusing on the tibial anterior surface (TAS) angle, tibial lateral surface (TLS) angleand tibiotalar ratio (TTR). Additionally, data regarding the time from the preoperative computed tomography (CT) scan to surgery, associated proceduresand complications were recorded. No associated procedures were performed, and only one intraoperative complication, an iatrogenic lateral malleolar fracture, was recorded. In the coronal plane, custom-made TAA with PSI consistently achieved precise positioning of prosthetic components, even in cases with significant preoperative deformities or bone deficits. However, a statistically significant deviation from the planned values was observed in the sagittal plane (p = 0.007). A notable correlation was identified between the time elapsed from the preoperative CT scan to surgery and the deviation from the planned to the actual postoperative TAS angle (p < 0.001). This study underscores the efficacy of PSI systems in achieving precise positioning in the coronal plane, in accordance with preoperative planning. In contrast, sagittal plane positioning did not demonstrate the same level of accuracy, as evidenced by a statistically significant difference between the planned and postoperative TLS values. Nevertheless, all measurements remained within the recommended range according to the existing literature. Level IV.

Chronic anterior shoulder instability with bone loss: a practical approach.

The stability of the glenohumeral joint, known for its remarkable mobility, relies on several factors, including the congruency of the joint's bones and the integrity of capsulolabral structures, encompassing the labrum, the capsule, and the glenohumeral ligaments. In cases of anterior shoulder instability, bone lesions are a common occurrence, most frequently involving glenoid bone loss and Hill-Sachs lesions. When both glenoid and humeral bone lesions coexist, the isolated Bankart procedure has exhibited a significant rate of failure. In such instances, the Latarjet procedure, especially when bone loss is present, retains its position as the gold standard, thanks to its consistent success in both short- and long-term outcomes. Recent advancements in research have explored alternative strategies to address bone loss, including the Remplissage procedure for humeral bone deficits and the use of bone block grafts to manage glenoid bone lesions, with a focus on achieving more anatomical techniques. However, it's crucial to recognize that, beyond bone loss, a multitude of intrinsic and extrinsic factors come into play when determining the most suitable treatment. The patient's profile, including factors like constitutional laxity and activity level, must be carefully considered in the decision-making process. The Latarjet procedure maintains its esteemed status as a benchmark in the field, thanks to its consistent excellence in both short- and long-term results. This article seeks to provide insights into the roles and placement of various surgical techniques within the context of chronic anterior shoulder instability, taking into account the intricate interplay of factors that influence treatment decisions.

Relationship between gut microbiome and bone deficits in primary hyperparathyroidism: A proof-of-concept pilot study.

Parathyroid hormone (PTH) interacts with components of the gut microbiota to exert its bone-regulating effects. This study aimed to investigate the gut microbial composition in patients with primary hyperparathyroidism (PHPT). Nine patients with PHPT and nine age-sex and body mass index-matched healthy controls were included. Gut microbial composition was assessed using 16S rRNA gene amplicon sequencing in both groups at baseline and 1 month after parathyroidectomy in the PHPT group. Data were imported into QIIME-2 and both QIIME-2 and R packages were used for microbiome analysis. Alpha and beta diversities were similar between the groups and remained unchanged after parathyroidectomy. The relative abundance of Subdoligranulum was significantly higher, whereas Ruminococcus, Alloprevotella, Phascolarctobacterium, and Clostridium sensu stricto_1 were significantly lower in PHPT than in controls (p < 0.001). After parathyroidectomy, the relative abundance of Subdoligranulum decreased, and Ruminococcus and Alloprevotella increased (p < 0.001). The PHPT group had lower total femoral and lumbar bone mineral density (BMD) than the controls (p < 0.05). At baseline, Alloprevotella abundance was positively correlated with serum phosphorus and Subdoligranulum was positively correlated with total lumbar BMD. Clostridium sensu stricto_1 was negatively correlated with serum calcium and positively correlated with femoral neck BMD. Postoperatively, Alloprevotella was positively correlated with baseline serum phosphorus and Phascolarctobacterium was positively correlated with distal radius BMD. This study demonstrated that the diversity of the gut microbiome was altered, possibly in response to electrolyte changes in PHPT, both before and after parathyroidectomy.

Microvascular development and remodeling

Skeletal fragility is an important complication of Type 1 Diabetes (T1D), particularly among older adults. Microvascular disease (MVD) has been linked to worse bone health in T1D, suggesting a potential direct pathophysiologic link between vascular disease and bone deficits. However, bone vascular control has not been explored in the context of T1D. Thus, this preliminary work investigates key mechanisms of regulation of the bone vasculature in older adults with T1D. Myogenic vasoconstriction and reactive hyperemia of tibial blood flow were assessed in older healthy adults (n=9, 65 ± 7 yrs) and older adults with T1D (n=10, 63 ± 6 yrs). Myogenic vasoconstriction was assessed in response to leg dependency (two levels of increased arterial transmural pressure obtained by lowering the leg below heart level) and reactive hyperemia was assessed in response to lower leg arterial occlusion via thigh cuff inflation. The initial peak reactive hyperemic response was considered a surrogate of myogenic vasodilation. For both stimuli, tibial blood flow was assessed via NIRS as total hemoglobin (tHb) and whole leg blood flow velocity (LBF) in the popliteal artery of the same leg was measured via Doppler ultrasound. Data are presented as mean±standard error. In response to leg dependency, with increased perfusion pressure, older adults had a tendency for smaller declines in LBF (L1: -3.85 ± 2.01 cm/s; L2: -6.22 ± 4.19 cm/s) compared to older adults with T1D (L1: -6.14 ±2.24 cm/s; L2: -10.4 ± 1.90 cm/s; group p=0.06, level p=0.07). Tibial tHb did not decline in older adults (L1: 1.16 ± 7.27 M; L2: 9.11 ± 13.8 M), but decreased progressively in those with T1D (L1: - 3.40 ± 2.79 M, L2: -6.14 ± 2.24 M, group p&lt;0.01, group*level p=0.07), indicating pronounced tibial myogenic vasoconstriction. In response to reactive hyperemia, LBF increased rapidly with cuff release in both groups (older adults: 50.8 ±22.7cm/s; T1D: 40.0 ± 13.4cm/s). Despite similar responses in LBF, tibial tHb surpassed baseline values in older adults (1.50 ± 5.35M), whereas tibial tHb did not reach baseline values within 5 min post cuff release in T1D (-2.85 ± 5.09M, p=0.09), indicating impaired tibial myogenic vasodilation. Interestingly, older adults with T1D and MVD (n=5) had a stronger tendency for greater tibial myogenic vasoconstriction at both levels and significantly impaired reactive hyperemic response compared to those with no MVD (n=5). Our preliminary results indicate that older adults with T1D have greater myogenic vasoconstriction and impaired reactive hyperemic responses that appear to be worse in the presence of MVD. Alterations in myogenic control act to compromise blood flow regulation, restricting blood flow to bone, and potentially contributing to diabetes-inducted skeletal fragility. NIH NIDDK R01 DK124710. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Lower bone strength in young patients with Fontan circulation compared to controls.

Previous reports indicate bone deficits in patients with Fontan circulation. However, the consequences of these deficits on bone strength and when these changes occur are unclear. To compare the tibial bone strength-strain index between young patients (6-19 years) with Fontan circulation and age- and sex-matched controls, and to determine strength-strain-index in subgroups of children (6-12 years) and adolescents (13-19 years) versus controls. The tibia was examined with peripheral quantitative CT. Based on the assessed data, bone strength-strain index was calculated in the lateral and anterior-posterior directions. Twenty patients with Fontan and twenty controls (mean age 13.0 ± 4.4 years; 50% females) were examined. Patients had a lower strength-strain index in the lateral direction compared to controls (808.4 ± 416.8mm3 versus 1162.5 ± 552.1mm3, p = 0.043). Subgroup analyses showed no differences regarding strength-strain index in children (6-12 years) with Fontan circulation compared to controls. However, the adolescents (13-19 years) with Fontan circulation had lower strength-strain indexes in both the lateral and anterior-posterior directions compared to controls (1041.4 ± 299.8mm3 versus 1596.4 ± 239.6mm3, p < 0.001, and 771.7 ± 192.4mm3 versus 1084.9 ± 215.0mm3, p = 0.004). When adjusted for height, there were differences between patients (6-19 years) and controls in strength-strain indexes in both the lateral and anterior-posterior directions. In subgroup analyses, the results remained robust. Young patients (6-19 years) with Fontan circulation have a lower strength-strain index in the tibia compared to controls. Subgroup analyses show that this deficit is mainly driven by the differences in adolescents (13-19 years), which might suggest that bone strength decreases with age.

Fracture risk based on high-resolution peripheral quantitative computed tomography measures does not vary with age in older adults-the bone microarchitecture international consortium prospective cohort study.

Fracture risk increases with lower areal bone mineral density (aBMD); however, aBMD-related estimate of risk may decrease with age. This may depend on technical limitations of 2-dimensional (2D) dual energy X-ray absorptiometry (DXA) which are reduced with 3D high-resolution peripheral quantitative computed tomography (HR-pQCT). Our aim was to examine whether the predictive utility of HR-pQCT measures with fracture varies with age. We analyzed associations of HR-pQCT measures at the distal radius and distal tibia with two outcomes: incident fractures and major osteoporotic fractures. We censored follow-up time at first fracture, death, last contact or 8years after baseline. We estimated hazard ratios (HR) and 95%CI for the association between bone traits and fracture incidence across age quintiles. Among 6835 men and women (ages 40-96) with at least one valid baseline HR-pQCT scan who were followed prospectively for a median of 48.3months, 681 sustained fractures. After adjustment for confounders, bone parameters at both the radius and tibia were associated with higher fracture risk. The estimated HRs for fracture did not vary significantly across age quintiles for any HR-pQCT parameter measured at either the radius or tibia. In this large cohort, the homogeneity of the associations between the HR-pQCT measures and fracture risk across age groups persisted for all fractures and for major osteoporotic fractures. The patterns were similar regardless of the HR-pQCT measure, the type of fracture, or the statistical models. The stability of the associations between HR-pQCT measures and fracture over a broad age range shows that bone deficits or low volumetric density remain major determinants of fracture risk regardless of age group. The lower risk for fractures across measures of aBMD in older adults in other studies may be related to factors which interfere with DXA but not with HR-pQCT measures.

Viability Test of Hydroxyapatite Tooth Graft on Osteoblast cell culture

Surgery is required to restore bone loss brought on by regenerative periodontal diseases while retaining the patient's aesthetics. The bone deficits caused by periodontal disease have been repaired using a variety of transplant materials. One of the graft materials used is dentin since it resembles bone in terms of both organic and inorganic components. In order to evaluate the viability of dental grafts, this study intended to count the osteoblast cells that were still alive after a specific therapy. Osteoblast cell cultures in 42 well plates were employed in this work. The 42 well plate cell cultures were separated into seven groups for 24hour examinations and seven groups for 48 hour examinations in order to examine the cells using the MTT assay. Each group contained control cells, control media devoid of cells, and the treatment group, which received tooth transplant at doses of 8, 4, 2, 1, and 0.5mg/mL. Using an ELISA reader with a 595nm wavelength, the optical density of these cells was used to determine the viability of the cells. There are more than 50% of osteoblast cells in all concentrations, which is indicated by the number of these cells. The Shapiro-Wilk, Levene, and Oneway Anova tests were performed to assess the normality, uniformity, and degree of group differences in the data. This study demonstrates the biocompatibility of the tooth graft and the osteoblast cells.

Acute Free Fibula Reconstruction of a Ballistic Ulna Fracture

Long bone reconstruction is a complicated topic, especially in cases with a large bone deficit where traditional fixation methods would lead to a high rate of non-union requiring further surgical intervention. Our case is of a male with a gunshot wound to his ulna resulting in a 10cm bone defect and a 15x8cm soft tissue defect. Our goal was to maintain a both bone forearm by reconstructing his ulna to maintain forearm pronation and supination. A chimeric free fibula flap was transferred in the acute setting. Vascularized bone transfer in upper extremity reconstruction is typically considered as an operation after fracture non-union. We propose the use of a vascularized bone flap as a first line therapy in certain instances such as the case above. The use of the free fibula flap can provide vascularized bone and softs tissues and allow for optimal recovery while decreasing the need for further operations.

Salvage First Metatarsophalangeal Joint Fusion with a Three-Dimensional-Printed Implant for Osseous Defects: A Case Series.

In this study, we aimed to describe a case series of revision first metatarsophalangeal joint fusion with a three-dimensional (3-D)-printed implant for osseous deficits of the first metatarsophalangeal joint. Bone defects of the first ray are a common problem in foot and ankle surgery. Etiologies include nonunion, avascular necrosis, osteomyelitis, failed first metatarsophalangeal joint implant arthroplasty, and failed hemijoint resection arthroplasty. Treatment options include acute shortening, block allograft, block autograft, distraction osteogenesis, vascularized free fibula, Masquelet technique, and partial first-ray amputation. Three-dimensional printing provides an opportunity to improve outcomes, with less donor site morbidity and less extensive recovery time than an external fixation device. It has been used in other facets of foot and ankle surgery with encouraging results. Three patients (four feet) underwent revision first metatarsophalangeal joint fusion with a 3-D-printed implant. Reasons for revision included avascular necrosis after distal metatarsal osteotomy in one patient and bone deficit after failed first metatarsophalangeal joint implant in two patients. All patients had a minimum follow up of 12 months. Two patients had painful hardware and had to undergo revision due to implant design. At most recent follow up all patients were pain free with improved pain scores. In revisional first metatarsophalangeal joint surgery with osseous deficits, the goal is to restore length and alignment, which improves function of the medial column. Custom 3-D-printed implants for first metatarsophalangeal joint revision can provide an opportunity for improved outcomes and healing.

Modular versus monoblock stem in revision total hip arthroplasty: a systematic review and meta-analysis.

Total hip arthroplasty (THA) is estimated to grow in the following decades with a consequent increase of THA revisions (rTHA). This systematic review and meta-analysis aims to compare modular and monoblock stem in rTHA surgery, focusing on clinical and radiological outcomes and complication rates. A literature search was performed using the following search strategy: ((Modular stem) OR (monolithic stem)) AND (hip review) on PubMed, Scopus, and Cochrane. Randomized controlled trials (RCTs) and observational studies (OS) compared clinical and radiological outcomes, and complication rates for monoblock and modular revision femoral stem were included. The risk of bias was assessed through the Methodological Index for Non-Randomized Studies (MINORS) score. The Review Manager (RevMan) software was used for the meta-analysis. The rate of complications was assessed using odds ratio (OR) with 95% confidence intervals (CIs). The authors included 11 OS and one RCT with 3,671 participants (mean age: 68.4 years old). The mean follow-up was 46.9 months. There was no prevalence of subsidence for one type of stem. Mean subsidence was from 0.92 to 10 mm for modular stem and from 1 to 15 mm for monoblock stem. Postoperative Harris Hip Score (HHS) showed better results with modular stems without statistical significance [mean difference (MD) =1.32; 95% CI: -1.62 to 4.27; P=0.38]. No statistically significant difference was found for dislocations (OR =2.48; 95% CI: 0.67 to 9.14; P=0.17), infections (OR =1.07; 95% CI: 0.51 to 2.23; P=0.86), intraoperative fractures (OR =1.62; 95% CI: 0.42 to 6.21; P=0.48), and postoperative fractures (OR =1.60; 95% CI: 0.55 to 4.64; P=0.39). Modular and monoblock stems show comparable and satisfactory clinical and radiological outcomes for rTHA. Both stems are valid and effective options for managing femoral bone deficit in hip revision surgery. The main limitation of this study is the small number and low quality of enclosed studies that compared the two stems. Moreover, the modular stem is usually used for more complex cases with lower quality femoral bone stock.

Successful Limb Salvage Reconstruction Using Bulk Femoral Head Allograft

Category: Ankle Introduction/Purpose: The use of femoral head allografts in salvage surgeries for lower extremity reconstruction help address surgical problems of large bone deficits. There are very few publications and mixed results in the literature as to the outcomes of this salvage procedure. These limb salvage procedures involve significant surgical complexity with the end goal of retaining a stable, brace-able lower extremity. The purpose of this retrospective review is to report the results and utility of bulk femoral head allograft for limb salvage including time to weight bearing, CT confirmed fusion time, reoperation rates, and ultimate limb salvage success. Additionally, this article categorizes femoral head surgical preparation, adjunct biologics use, fixation constructs, and dissection techniques used. Methods: Patients who underwent reconstructive limb salvage surgery using femoral head allografts over a 5-year period (2015- 2020) were identified. The surgeries were among 5 different fellowship-trained surgeons at a single institution. Indications included post-traumatic AVN, Charcot ankle, revisional surgery, and failed total ankle replacement. Femoral heads were used in either ankle fusions alone or in tibiotalocalcaneal fusion. Time to weight bearing, CT fusion time, reoperations, and ultimate limb salvage were recorded. Reoperations were reported minor if involved partial HWR, superficial I&amp;Ds, or exostosis/HO removal. Major reoperations were defined as full revision surgery/failure of femoral head construct, placement of antibiotic rods for deep infection, or BKA. Limb salvage was defined as being successful if the patient was walking with or without bracing at the last follow-up. Results: Twenty-three cases were identified with 13 performed for failed total ankle replacements, 7 post-traumatic avascular necrosis of the talus, and 3 neuropathic Charcot ankles. The average radiographic follow-up time was 665 days with an average time to weight bearing of 86.48 days. 18/23 patients had CT confirmation of femoral graft union with an average time to union of 461.92 days. 9 patients were found to have less than 50% graft incorporation at the last follow-up. There were 9 reoperations recorded, 8 minor and 1 major. All patients were chart documented stable with independent weight bearing either with or without a brace on the last clinic follow-up. Conclusion: Limb salvage in cases of large bone defects can be very challenging. We report a high success rate of limb salvage using bulk femoral head allograft. Complete fusion of bulk femoral head allograft although desirable, was not necessary to maintain limb salvage in this retrospective study. Patients were able to weight bear and maintain the integrity of the bulk allograft despite the lengthy time to achieve fusion in cases where fusion was achieved. This study highlights that bulk femoral head allograft can offer excellent salvage options with a high degree of success in complex limb salvage reconstruction.

Allograft Prosthesis Composite (APC) for Proximal Humeral Bone Loss: Outcomes and Perspectives.

(1) Background: Allograft prosthetic composite (APC) represents one of the techniques used for reconstruction in large proximal humeral bone deficits. The present systematic review aimed at summarizing the state of the art of the technique and analyzing its outcomes. (2) Methods: The PRISMA guidelines were followed to perform this systematic review. A systematic electronic search was performed using PubMed (MEDLINE), EMBASE, and the Cochrane Library databases. All the studies analyzing the rates of allograft prosthesis composite were pooled, and the data were extracted and analyzed. (3) Results: A total of 10 studies were eligible for inclusion in this systematic review for a total of 239 patients. The rate of patient satisfaction with surgery was reported in 7 studies with a mean of 86.4% ± 13.64. The mean constant score was 45.7 ± 3.51, the mean ASES score was 63.58 ± 8.37, and the mean SST was 4.6 ± 1.04. The mean revision rate observed was 10.32% ± 3.63 and the mean implant survival was 83.66% ± 14.98. (4) Conclusions: Based on the currently available data, allograft prosthesis composite represents a valuable option for the reconstruction of proximal humeral deficits. All studies analyzed showed the favorable impact of this surgical technique on clinical outcomes and patient satisfaction.

The use of 3D printing technology in limb reconstruction. Inspirations and challenges

The management of septic non-unions with associated bone necrosis is challenging, especially when the resulting bone defect after the debridement is extensile. Different techniques have been described in the literature for the treatment of these demanding cases, with the most prominent being free vascularized Fibular graft and bone transport with distraction osteogenesis principles. Recently, 3D printing technology has been increasingly utilized in many complex orthopaedic pathologies. However, the application of those advancements regarding septic non-unions with residual bone defect has not been previously studied. This study presents a novel 3D printing technique for the management of an infected critical bone deficit of the tibia. Queries, challenges and future perspectives concerning the recruiting of 3D printing technology in limb reconstruction are also being discussed. Clinical Evidence Level: IV.