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Introduction: Ambulation can be used to monitor the healing of lower extremity fractures. However, the ambulatory behavior of tibia fracture patients remains unknown due to an inability to continuously quantify ambulation outside of the clinic. The goal of this study was to design and validate an algorithm to assess ambulation in tibia fracture patients using the ambulatory tibial load analysis system during recovery, outside of the clinic.

Insects are among the most diverse groups of animals on Earth. Their cuticle exoskeletons vary greatly in terms of size and shape, and are subjected to different applied forces during daily activities. We investigated the biomechanics of the tibiae of three different insect species: the desert locust (Schistocerca gregaria), American cockroach (Periplaneta americana) and Death's Head cockroach (Blaberus discoidalis). In a previous work, we showed that these tibiae vary not only in geometry (length, radius and thickness) but also in material quality (Young's modulus) and in the applied stress required to cause failure when loaded in bending. In the present work we used kinematic data from the literature to estimate the forces and stresses arising in vivo for various different activities, and thus calculated factors of safety defined as the ratio between the failure stress and the in vivo stress, adjusting the failure stress to a lower value to allow for fatigue failure in the case of frequently repeated activities. Factors of safety were found to vary considerably, being as little as 1.7 for the most strenuous activities, such as jumping or escaping from tight spaces. Our results show that these limbs have evolved to the point where they are close to optimal, and that instantaneous failure during high-stress activities is more critical than long-term fatigue failure. This work contributes to the discussion on how form and material properties have evolved in response to the mechanical functions of the same body part in different insects.

Varus malalignment of the tibia could alter ankle biomechanics, and might lead to degenerative changes of the ankle joint. However, previous studies failed to report the detailed changes of ankle biomechanics in varus malalignment of the tibia. The aim of this biomechanical study was to evaluate how the ankle joint pressure would change in response to the incremental increases in varus malalignment of the tibia.

Trampoline-related fractures of the proximal tibial metaphysis are common in children and have been linked to subsequent valgus deformity of the tibia. The purpose of this study was to investigate the characteristics of trampoline-related proximal tibial fractures in young children.

Several experimental models of osteoarthritis in rats are used to study the pathophysiology of osteoarthritis. Many mechanically induced models have the limitation that permanent joint instability is induced by, for example, ligament transection or meniscal damage. This permanent instability will counteract the potential beneficial effects of therapy. The groove model of osteoarthritis uses a one-time trigger, surgically induced cartilage damage on the femoral condyles, and has been validated for the canine tibia-femoral compartment. The present study evaluates this model for the rat knee joint. The articular cartilage of the weight bearing surface of both femoral condyles and trochlea were damaged (grooved) without damaging the underlying subchondral bone. Severity of joint degeneration was histologically assessed, in addition to patella cartilage damage, and subchondral bone characteristics by means of (contrast-enhanced) micro-CT. Mild histological degeneration of the surgically untouched tibial plateau cartilage was observed in addition to damage of the femoral condyles, without clear synovial tissue inflammation. Contrast enhanced micro-CT demonstrated proteoglycan loss of the surgically untouched patella cartilage. Besides, a more sclerotic structure of the subchondral bone was observed. The tibia-femoral groove model in a rat results in mild knee joint degeneration, without permanent joint instability and joint inflammation. This makes the rat groove model a useful model to study the onset and progression of post-traumatic non-inflammatory osteoarthritis, creating a relatively sensitive model to study disease modifying osteoarthritic drugs. © 2016 The Authors. Journal of Orthopaedic Research published by Wiley Periodicals, Inc. on behalf of the Orthopaedic Research Society. J Orthop Res 35:496-505, 2017.

Tibial plateau fracture classifications are based on anteroposterior radiographs. Precontoured locking plates are commonly used to treat such fractures. The aims of this study are to: (1) describe tibial plateau fracture anatomy in the axial plane and (2) assess whether current plating systems allow screws to be placed suitably.

Tibia fractures are common in pediatric patients and time necessary to return to normal function may be underappreciated. The purpose of this study was to assess functional recovery in pediatric patients who sustain tibia fractures, utilizing the Pediatrics Outcome Data Collection Instrument (PODCI), in order to provide evidence-based information on post-injury functional limitations and anticipated recovery times.

The model of bilaterally ovariectomized rats mimics the accelerated bone loss observed in postmenopausal women due to estrogen deficiency. Although calcium is main mineral in bone, previous study in human showed there is hypermineralization and higher calcium level in hydroxyapatite crystal structure from osteoporosis patients. This study was aimed to investigate the effect of time course ovariectomized on tibia bone turn over markers, mineral elements, hydroxyapatite crystale, mesostructure, and histomorphometry.

Open tibia fractures are a major source of disability in low- and middle-income countries (LMICs) due to the high incidence of complications, particularly infection and chronic osteomyelitis. One proposed adjunctive measure to reduce infection is prophylactic local antibiotic delivery, which can achieve much higher concentrations at the surgical site than can safely be achieved with systemic administration. Animal studies and retrospective clinical studies support the use of gentamicin for this purpose, but no high-quality clinical trials have been conducted to date in high- or low-income settings.

The skeleton is a vital organ providing structural support in poultry. Weakness in bone structure can lead to deformities, osteoporosis, cage fatigue, and fractures, resulting in economic losses. Research has substantiated that genetic factors play a significant role in influencing bone quality. The discovery of genetic markers associated with bone quality holds paramount importance for enhancing genetic traits related to the skeletal system in poultry. This study analyzed nine phenotypic indicators of tibia quality in 120-day-old ducks. The phenotypic correlation revealed a high correlation among diameter, Perimeter, and weight (0.69-0.78), and a strong correlation was observed between toughness and breaking strength (0.62). Then, we conducted a genome-wide association analysis of the phenotypic indicators to elucidate the genetic basis of tibial quality in Nonghua ducks. Among the 11 candidate genes that were annotated, TAPT1, BST1, and STIM2 were related to the diameter indicator, ZNF652, IGF2BP1, CASK, and GREB1L were associated with the weight and toughness indicators. RFX8, GLP1R, and DNAAF5 were identified for ash, calcium, and phosphorus content, respectively. Finally, KEGG and GO analysis for annotated genes were performed. STIM2 and BST1 were enriched into the Calcium signalling pathway and Niacin and nicotinamide metabolic pathway, which may be key candidate genes affecting bone quality phenotypes. Gene expression analysis of the candidate genes, such as STIM2, BST1, TAPT1, and CASK showed higher expression levels in bones compared to other tissues. The obtained results can contribute to new insights into tibial quality and provide new genetic biomarkers that can be employed in duck breeding.

Mycobacterium senegalense infection is rare. We present the third documented case of M. senegalense infection and the first to involve the musculoskeletal system. A 55-year old immunocompetent male developed chronic osteomyelitis of the ankle and required antibiotic spacers, an Ilizarov external fixator and multiple antibiotic regimens to eradicate the infection.

To determine the ideal entry point and direction of retrograde intramedullary nailing of the tibia.

Optimal treatment for acute post-traumatic bone loss in the tibia remains unclear. Distraction osteogenesis (DO) and induced membrane technique (IM) have been established as the mainstays of treatment. Aim of this article is to review the current evidence regarding the use of these two methods.

The development of predictive mathematical models can contribute to a deeper understanding of the specific stages of bone mechanobiology and the process by which bone adapts to mechanical forces. The objective of this work was to predict, with spatial accuracy, cortical bone adaptation to mechanical load, in order to better understand the mechanical cues that might be driving adaptation. The axial tibial loading model was used to trigger cortical bone adaptation in C57BL/6 mice and provide relevant biological and biomechanical information. A method for mapping cortical thickness in the mouse tibia diaphysis was developed, allowing for a thorough spatial description of where bone adaptation occurs. Poroelastic finite-element (FE) models were used to determine the structural response of the tibia upon axial loading and interstitial fluid velocity as the mechanical stimulus. FE models were coupled with mechanobiological governing equations, which accounted for non-static loads and assumed that bone responds instantly to local mechanical cues in an on-off manner. The presented formulation was able to simulate the areas of adaptation and accurately reproduce the distributions of cortical thickening observed in the experimental data with a statistically significant positive correlation (Kendall's τ rank coefficient τ = 0.51, p < 0.001). This work demonstrates that computational models can spatially predict cortical bone mechanoadaptation to a time variant stimulus. Such models could be used in the design of more efficient loading protocols and drug therapies that target the relevant physiological mechanisms.

Retrograde labeling has been used to identify sensory neurons in the lumbar dorsal root ganglia (DRG) that innervate the rat tibial periosteum, medullary cavity, and trabecular bone. The size, neurochemical profile [isolectin B4 (IB4) binding, substance P (SP), calcitonin gene-related peptide (CGRP), and NF200 immunoreactivity (-IR)], and segmental distribution of sensory neurons innervating each of these bony compartments are reported. After injections of fast blue into the periosteum, medullary cavity, and trabecular bone (epiphysis), retrogradely labeled neurons were observed throughout the ipsilateral (but not contralateral) lumbar DRG. They were predominantly small (<800 microm(2)) or medium-sized (800-1,800 microm(2)) neurons. CGRP-IR and SP-IR were found in 23% and 16% of the retrogradely labeled neurons, respectively. IB4 binding was observed in 20% and NF200-IR in 40% of the retrogradely labeled neurons. There were no significant differences in the percentage of neurons labeled with any one of the antisera following injections into each of the three bony compartments. To allow a direct comparison with sensory neurons innervating cutaneous tissues, injections of fast blue were also made into the skin overlying the tibia. The percentage of CGRP-IR neurons innervating bone was significantly lower than the percentage of CGRP-IR neurons innervating skin (ANOVA; P < 0.05). No other significant differences in the neurochemical profiles of neurons labeled from bone vs. skin were observed. The findings of the present study show that the periosteum, medullary cavity, and trabecular bone are all innervated by sensory neurons that have size and neurochemical profiles consistent with a role in nociception.

Osteomyelitis refers to an inflammatory process causing bone destruction and necrosis. Managing such a persistent disease is complex, with a number of authors reporting different techniques. This scoping review aims to map and summarize the literature on treatment of chronic femoral and tibial osteomyelitis, in order to improve the reader's understanding of potential treatments and identify areas of further research.The methodological framework of the Joanna Briggs Institute was followed. A computer-based search was conducted in PubMed, EMBASE, MEDLINE, EMCARE and CINAHL, for articles reporting treatment of chronic tibial/femoral osteomyelitis. Two reviewers independently performed title/abstract and full-text screening according to pre-defined criteria.A total of 1230 articles were identified, with 40 finally included. A range of treatments are reported, with the core principles being removal of infected tissue, dead-space management and antibiotic therapy. The majority (84.5%) of patients presented with stage III or IV disease according to the Cierny-Mader classification, and Staphylococcus aureus was the most commonly isolated organism. The proportion of patients achieving remission with no recurrence during follow-up varies from 67.7-100.0%.The majority of studies report excellent outcomes in terms of infection remission and lack of recurrence. However, identifying specific patient or treatment-related factors which may affect outcomes is currently challenging due to the nature of the included studies and unclear reporting of treatment outcomes. It is now important to address this issue and identify such factors using further high-level research methods such as randomized controlled trials and comparative cohort studies. Cite this article: EFORT Open Rev 2021;6:704-715. DOI: 10.1302/2058-5241.6.200136.

The few available studies documenting the long-term survival of cemented proximal tibial endoprostheses for musculoskeletal tumors do not differentiate between stem designs or patient diagnosis. There is wide variation in survival rates reported, possibly a result of this heterogeneity in patient population and implant design.

Emerging evidence suggests that Complex Regional Pain Syndrome (CRPS) is in part a post-traumatic autoimmune disease mediated by an adaptive immune response after limb injuries. We previously observed in a murine tibial fracture model of CRPS that pain-related behaviors were dependent upon adaptive immune mechanisms including the neuropeptide-dependent production of IgM for 5 months after injury. However, the time course of induction of this immune response and the demonstration of germinal center formation in lymphoid organs has not been evaluated. Using the murine fracture model, we employed behavioral tests of nociceptive sensitization and limb dysfunction, serum passive transfer techniques, western blot analysis of IgM accumulation, fluorescence-activated cell sorting (FACS) of lymphoid tissues and immunohistochemistry to follow the temporal activation of the adaptive immune response over the first 3 weeks after fracture. We observed that: 1) IgM protein levels in the skin of the fractured mice were elevated at 3 weeks post fracture, but not at earlier time points, 2) serum from fracture mice at 3 weeks, but not 1 and 2 weeks post fracture, had pro-nociceptive effects when passively transferred to fractured muMT mice lacking B cells, 3) fracture induced popliteal lymphadenopathy occurred ipsilateral to fracture beginning at 1 week and peaking at 3 weeks post fracture, 4) a germinal center reaction was detected by FACS analysis in the popliteal lymph nodes from injured limbs by 3 weeks post fracture but not in other lymphoid tissues, 5) germinal center formation was characterized by the induction of T follicular helper cells (Tfh) and germinal center B cells in the popliteal lymph nodes of the injured but not contralateral limbs, and 6) fracture mice treated with the Tfh signaling inhibitor FK506 had impaired germinal center reactions, reduced IgM levels, reduced nociceptive sensitization, and no pronociceptive serum effects after administration to fractured muMT mice. Collectively these data demonstrate that tibia fracture induces an adaptive autoimmune response characterized by popliteal lymph node germinal center formation and Tfh cell dependent B cell activation, resulting in nociceptive sensitization within 3 weeks.

Introduction: The in vivo tibial loading mouse model has been extensively used to evaluate bone adaptation in the tibia after mechanical loading treatment. However, there is a prevailing assumption that the load is applied axially to the tibia. The aim of this in silico study was to evaluate how much the apparent mechanical properties of the mouse tibia are affected by the loading direction, by using a validated micro-finite element (micro-FE) model of mice which have been ovariectomized and exposed to external mechanical loading over a two-week period. Methods: Longitudinal micro-computed tomography (micro-CT) images were taken of the tibiae of eleven ovariectomized mice at ages 18 and 20 weeks. Six of the mice underwent a mechanical loading treatment at age 19 weeks. Micro-FE models were generated, based on the segmented micro-CT images. Three models using unitary loads were linearly combined to simulate a range of loading directions, generated as a function of the angle from the inferior-superior axis (θ, 0°-30° range, 5° steps) and the angle from the anterior-posterior axis (ϕ, 0°: anterior axis, positive anticlockwise, 0°-355° range, 5° steps). The minimum principal strain was calculated and used to estimate the failure load, by linearly scaling the strain until 10% of the nodes reached the critical strain level of -14,420 με. The apparent bone stiffness was calculated as the ratio between the axial applied force and the average displacement along the longitudinal direction, for the loaded nodes. Results: The results demonstrated a high sensitivity of the mouse tibia to the loading direction across all groups and time points. Higher failure loads were found for several loading directions (θ = 10°, ϕ 205°-210°) than for the nominal axial case (θ = 0°, ϕ = 0°), highlighting adaptation of the bone for loading directions far from the nominal axial one. Conclusion: These results suggest that in studies which use mouse tibia, the loading direction can significantly impact the failure load. Thus, the magnitude and direction of the applied load should be well controlled during the experiments.