Long bone uninfected non-union: grafting techniques

Long bone non-unions represent a serious clinical and socioeconomical problem due to the prolonged episodes, frequent sequelae, and variable treatment effectiveness. Bone grafts, classically involving the autologous iliac crest graft as the 'gold standard' bone graft, enhance bone regeneration and fracture healing incorporating osteoconductive and/or osteoinductive/osteogenic capacity to the non-union under treatment. Structural alternatives to autologous bone grafts include allografts and bone substitutes, expanding the available stock but loosing biological properties associated with cells in the graft. Biological alternatives to autologous bone grafts include bone marrow concentration from iliac crest aspiration, bone marrow aspiration from reaming of the diaphyseal medullary canal in the long bones, and isolated, expanded mesenchymal stem cells under investigation. When the combination with natural and synthetic bone substitutes allows for larger volumes of structural grafts, the enhancement of the biological regenerative properties through the incorporation of cells and their secretoma permits to foresee new bone grafting solutions and techniques.

Clinical efficacy and complications of blocking screw in the treatment of lower limb long bone fracture: An updated systematic review and meta-analysis

BACKGROUND

Blocking screw technique has been widely applied in the treatment of long shaft fractures. However, the evidence with regard to whether intramedullary nail combined with blocking screw technique has better clinical efficacy over other is not clear. The aim of the study was to explore the clinical efficacy and complications of intramedullary nail combined with blocking screw technique in the treatment of femoral or tibial shaft fractures.

METHODS

The PuMed, Embase, OVID, Cochrane library, Web of Science, Wanfang, CNKI and Weipu data were searched for studies of intramedullary nail combined with blocking screw in treatment of femoral or tibial shaft fracture published up to Aug 31 2023. Methodological quality of the trials was assessed, relevant data were extracted, and RevMan 5.3 and Stata 15.0 software were used to perform the meta-analysis of parameters related to the consequences.

RESULT

Twenty articles were included, including 1267 patients. Meta-analysis results showed that compared with the non-blocking screw group, the blocking screw group had longer operation time (WMD = 13.24; 95% CI = 5.68-20.79, P = .0006) and more intraoperative fluoroscopy times (WMD = 57.62; 95% CI = 25.82-89.42, P = .0002). However, the postoperative therapeutic response rate was higher (OR = 5.60; 95% CI = 2.10-14.93, P = .0006), postoperative ankle joint function was better (OR = 3.48; 95% CI = 1.20-10.13, P = .02), and fracture healing rate was higher (OR = 3.56; 95% CI = 1.43-8.89, P = .006), fracture healing time was shorter (WMD = -3.59; 95% CI = -4.96 to -2.22, P < .00001), intraoperative blood loss was less (WMD = -54.80; 95% CI = -88.77 to -20.83, P = .002), hospitalization time was shorter (WMD = -1.66; 95% CI = -2.08 to -1.24, P < .00001), and complications were less (OR = 0.38; 95% CI = 0.16-0.89, P = .01). There was no statistical significance in the range of motion of knee joint between the 2 groups (WMD = 10.04; 95% CI = -1.51 to 21.59, P = .09).

CONCLUSIONS

Current evidence shows that intramedullary nail combined with blocking screw technique in the treatment of lower limb long bone fracture has the advantages of good clinical efficacy, high fracture healing rate, short fracture healing time, good joint function, less complications and so on, which is worthy of clinical recommendation.

Preventing Atrophic Long-Bone Nonunion: Retrospective Analysis at a Level I Trauma Center

Background: Among the risk factors for nonunion are unchangeable patient factors such as the type of injury and comorbidities, and factors that can be influenced by the surgeon such as fracture treatment and the postoperative course. While there are numerous studies analyzing unchangeable factors, there is poor evidence for factors that can be affected by the physician. This raises the need to fill the existing knowledge gaps and lay the foundations for future prevention and in-depth treatment strategies. Therefore, the goal of this study was to illuminate knowledge about nonunion in general and uncover the possible reasons for their development; Methods: This was a retrospective analysis of 327 patients from 2015 to 2020 from a level I trauma center in Germany. Information about patient characteristics, comorbidities, alcohol and nicotine abuse, fracture classification, type of osteosynthesis, etc., was collected. Matched pair analysis was performed, and statistical testing performed specifically for atrophic long-bone nonunion; Results: The type of osteosynthesis significantly affected the development of nonunion, with plate osteosynthesis being a predictor for nonunion. The use of wire cerclage did not affect the development of nonunion, nor did the use of NSAIDs, smoking, alcohol, osteoporosis and BMI; Conclusion: Knowledge about predictors for nonunion and strategies to avoid them can benefit the medical care of patients, possibly preventing the development of nonunion.

Surgical debridement in long bone chronic osteomyelitis: is wide tumour-like resection necessary?

Aims

The standard of wide tumour-like resection for chronic osteomyelitis (COM) has been challenged recently by adequate debridement. This paper reviews the evolution of surgical debridement for long bone COM, and presents the outcome of adequate debridement in a tertiary bone infection unit.

Methods

We analyzed the retrospective record review from 2014 to 2020 of patients with long bone COM. All were managed by multidisciplinary infection team (MDT) protocol. Adequate debridement was employed for all cases, and no case of wide resection was included.

Results

A total of 53 patients (54 bones) with median age of 45.5 years (interquartile range 31 to 55) and mean follow-up of 29 months (12 to 59) were included. In all, ten bones were Cierny-Mader type I, 39 were type III, and five were type IV. All patients were treated with single-staged management, except for one (planned two-stage stabilization). Positive microbial cultures grew in 75%. Overall, 46 cases (85%) had resolution of COM after index procedure, and 49 (90.7%) had resolution on last follow-up. Four patients (7%) underwent second surgical procedure and six patients (11%) had complications.

Conclusion

We challenge the need for wide tumour-like resection in all cases of COM. Through detailed preoperative evaluation and planning with MDT approach, adequate debridement and local delivery of high concentration of antibiotic appears to provide comparable outcomes versus radical debridement.

Low-cost locally manufacturable unilateral imperial external fixator for low- and middle-income countries

Treating open fractures in long bones can be challenging and if not performed properly can lead to poor outcomes such as mal/non-union, deformity, and amputation. One of the most common methods of treating these fracture types is temporary external fixation followed by definitive fixation. The shortage of high-quality affordable external fixators is a long-recognised need, particularly in Low- and Middle-Income Countries (LMICs). This research aimed to develop a low-cost device that can be manufactured locally to international standards. This can provide surge capacity for conflict zones or in response to unpredictable incidents and situations. The fixator presented here and developed by us, the Imperial external fixator, was tested on femur and tibia specimens under 100 cycles of 100 N compression-tension and the results were compared with those of the Stryker Hoffmann 3 frame. The Imperial device was stiffer than the Stryker Hoffmann 3 with a lower median interfragmentary motion (of 0.94 vs. 1.48 mm). The low-cost, easy to use, relatively lightweight, and easy to manufacture (since minimum skillset and basic workshop equipment and materials are needed) device can address a critical shortage and need in LMICs particularly in conflict-affected regions with unpredictable demand and supply. The device is currently being piloted in three countries for road traffic accidents, gunshot wounds and other conflict trauma-including blast cohorts.

Ganglionic Cyst of Periosteal Origin Mimicking as Pes Anserine Bursitis - A Rare Entity and Literature Review

Introduction

Periosteal ganglion is a form of cystic swelling commonly seen around long bones of lower extremities.

Case Report

A 55-year-old male presented to outdoor clinic with gradually increasing swelling around anteromedial aspect of the right knee joint with intermittent pain on prolonged standing and walking for 8 months. Magnetic resonance imaging was suggestive of ganglionic cyst which was confirmed later by histopathological examination.

Conclusion

Ganglionic cyst of periosteal origin is a rare entity. Complete excision is the recommended treatment option; if not performed appropriately chances of recurrence are high.

Contribution to the 3R Principle: Description of a Specimen-Specific Finite Element Model Simulating 3-Point-Bending Tests in Mouse Tibiae

Bone mechanical properties are classically determined by biomechanical tests, which normally destroy the bones and disable further histological or molecular analyses. Thus, obtaining biomechanical data from bone usually requires an additional group of animals within the experimental setup. Finite element models (FEMs) may non-invasively and non-destructively simulate mechanical characteristics based on material properties. The present study aimed to establish and validate an FEM to predict the mechanical properties of mice tibiae. The FEM was established based on µCT (micro-Computed Tomography) data of 16 mouse tibiae. For validating the FEM, simulated parameters were compared to biomechanical data obtained from 3-point bending tests of the identical bones. The simulated and the measured parameters correlated well for bending stiffness (R2 = 0.9104, p < 0.0001) and yield displacement (R2 = 0.9003, p < 0.0001). The FEM has the advantage that it preserves the bones’ integrity, which can then be used for other analytical methods. By eliminating the need for an additional group of animals for biomechanical tests, the established FEM can contribute to reducing the number of research animals in studies focusing on bone biomechanics. This is especially true when in vivo µCT data can be utilized where multiple bone scans can be performed with the same animal at different time points. Thus, by partially replacing biomechanical experiments, FEM simulations may reduce the overall number of animals required for an experimental setup investigating bone biomechanics, which supports the 3R (replace, reduce, and refine) principle.

Osteohistological and taphonomic life-history assessment of Edmontosaurus annectens (Ornithischia: Hadrosauridae) from the Late Cretaceous (Maastrichtian) Ruth Mason dinosaur quarry, South Dakota, United States, with implication for ontogenetic segregation between juvenile and adult hadrosaurids

The Late Cretaceous (Maastrichtian) Ruth Mason Dinosaur Quarry (RMDQ) represents a monodominant Edmontosaurus annectens bonebed from the Hell Creek Formation of South Dakota and has been determined as a catastrophic death assemblage likely belonging to a single population, providing an ideal sample to investigate hadrosaurid growth and population dynamics. For this study, size-frequency distributions were constructed from linear measurements of long bones (humeri, femora, tibiae) from RMDQ that revealed five relatively distinct size classes along a generally right-skewed distribution, which is consistent with a catastrophic assemblage. To test the relationship between morphological size ranges and ontogenetic age classes, subsets from each size-frequency peak were transversely thin-sectioned at mid-diaphysis to conduct an ontogenetic age assessment based on growth marks and observations of the bone microstructure. When combining these independent datasets, growth marks aligned with size-frequency peaks, with the exclusion of the overlapping subadult-adult size range, indicating a strong size-age relationship in early ontogeny. A growth curve analysis of tibiae indicated that E. annectens exhibited a similar growth trajectory to the Campanian hadrosaurid Maiasaura, although attaining a much larger asymptotic body size by about 9 years of age, further suggesting that the clade as a whole may have inherited a similar growth strategy. This rich new dataset for E. annectens provides new perspectives on other hypotheses of hadrosaurid life history. When the RMDQ population was compared with size distributions from other hadrosaurid bonebed assemblages, juveniles (categorized as ages one and two) were either completely absent from or heavily underrepresented in the samples, providing support for the hypothesized segregation between juvenile and adult hadrosaurids. Osteohistological comparison with material from polar and temperate populations of Edmontosaurus revealed that previous conclusions correlating osteohistological growth patterns with the strength of environmental stressors were a result of sampling non-overlapping ontogenetic growth stages.

Osteocyte-specific dentin matrix protein 1 : the role of mineralization regulation in low-magnitude high-frequency vibration enhanced osteoporotic fracture healing

Aims

There is an increasing concern of osteoporotic fractures in the ageing population. Low-magnitude high-frequency vibration (LMHFV) was shown to significantly enhance osteoporotic fracture healing through alteration of osteocyte lacuno-canalicular network (LCN). Dentin matrix protein 1 (DMP1) in osteocytes is known to be responsible for maintaining the LCN and mineralization. This study aimed to investigate the role of osteocyte-specific DMP1 during osteoporotic fracture healing augmented by LMHFV.

Methods

A metaphyseal fracture was created in the distal femur of ovariectomy-induced osteoporotic Sprague Dawley rats. Rats were randomized to five different groups: 1) DMP1 knockdown (KD), 2) DMP1 KD + vibration (VT), 3) Scramble + VT, 4) VT, and 5) control (CT), where KD was performed by injection of short hairpin RNA (shRNA) into marrow cavity; vibration treatment was conducted at 35 Hz, 0.3 g; 20 minutes/day, five days/week). Assessments included radiography, micro-CT, dynamic histomorphometry and immunohistochemistry on DMP1, sclerostin, E11, and fibroblast growth factor 23 (FGF23). In vitro, murine long bone osteocyte-Y4 (MLO-Y4) osteocyte-like cells were randomized as in vivo groupings. DMP1 KD was performed by transfecting cells with shRNA plasmid. Assessments included immunocytochemistry on osteocyte-specific markers as above, and mineralized nodule staining.

Results

Healing capacities in DMP1 KD groups were impaired. Results showed that DMP1 KD significantly abolished vibration-enhanced fracture healing at week 6. DMP1 KD significantly altered the expression of osteocyte-specific markers. The lower mineralization rate in DMP1 KD groups indicated that DMP1 knockdown was associated with poor fracture healing process.

Conclusion

The blockage of DMP1 would impair healing outcomes and negate LMHFV-induced enhancement on fracture healing. These findings reveal the importance of DMP1 in response to the mechanical signal during osteoporotic fracture healing.

Cite this article: Bone Joint Res 2022;11(7):465–476.

Extracorporeal Shockwave Therapy in the Treatment of Nonunion in Long Bones: A Systematic Review and Meta-Analysis

Background: Nonunion is one of the most challenging problems in the field of orthopedics. The aim of this study was to perform a systematic review of the literature to evaluate the effectiveness of extracorporeal shockwave therapy (ESWT) in the treatment of nonunion in long bones. Methods: We conducted a search of three databases (PubMed, Scopus, and Web of Science) and found 646 total publications, of which 23 met our inclusion criteria. Results: Out of 1200 total long bone nonunions, 876 (73%) healed after being treated with ESWT. Hypertrophic cases achieved 3-fold higher healing rates when compared to oligotrophic or atrophic cases (p = 0.003). Metatarsal bones were the most receptive to ESWT, achieving a healing rate of 90%, followed by tibiae (75.54%), femurs (66.9%) and humeri (63.9%). Short periods between injury and treatment lead to higher healing rates (p < 0.02). Conversely, 6 months of follow-up after the treatment appears to be too brief to evaluate the full healing potential of the treatment; several studies showed that healing rates continued to increase at follow-ups beyond 6 months after the last ESWT treatment (p < 0.01). Conclusions: ESWT is a promising approach for treating nonunions. At present, a wide range of treatment protocols are used, and more research is needed to determine which protocols are the most effective.

Excessive osteoclast activation by osteoblast paracrine factor RANKL is a major cause of the abnormal long bone phenotype in Apert syndrome model mice

The fibroblast growth factor (FGF)/FGF receptor (FGFR) signaling pathway plays important roles in the development and growth of the skeleton. Apert syndrome caused by gain‐of‐function mutations of FGFR2 results in aberrant phenotypes of the skull, midface, and limbs. Although short limbs are representative features in patients with Apert syndrome, the causative mechanism for this limb defect has not been elucidated. Here we quantitatively confirmed decreases in the bone length, bone mineral density, and bone thickness in the Apert syndrome model of gene knock‐in Fgfr2^S252W/+ (EIIA‐Fgfr2^S252W/+) mice. Interestingly, despite these bone defects, histological analysis showed that the endochondral ossification process in the mutant mice was similar to that in wild‐type mice. Tartrate‐resistant acid phosphatase staining revealed that trabecular bone loss in mutant mice was associated with excessive osteoclast activity despite accelerated osteogenic differentiation. We investigated the osteoblast–osteoclast interaction and found that the increase in osteoclast activity was due to an increase in the Rankl level of osteoblasts in mutant mice and not enhanced osteoclastogenesis driven by the activation of FGFR2 signaling in bone marrow‐derived macrophages. Consistently, Col1a1‐Fgfr2^S252W/+ mice, which had osteoblast‐specific expression of Fgfr2 S252W, showed significant bone loss with a reduction of the bone length and excessive activity of osteoclasts was observed in the mutant mice. Taken together, the present study demonstrates that the imbalance in osteoblast and osteoclast coupling by abnormally increased Rankl expression in Fgfr2^S252W/+ mutant osteoblasts is a major causative mechanism for bone loss and short long bones in Fgfr2^S252W/+ mice.

BMP3 Affects Cortical and Trabecular Long Bone Development in Mice

Bone morphogenetic proteins (BMPs) have a major role in tissue development. BMP3 is synthesized in osteocytes and mature osteoblasts and has an antagonistic effect on other BMPs in bone tissue. The main aim of this study was to fully characterize cortical bone and trabecular bone of long bones in both male and female Bmp3^−/− mice. To investigate the effect of Bmp3 from birth to maturity, we compared Bmp3^−/− mice with wild-type littermates at the following stages of postnatal development: 1 day (P0), 2 weeks (P14), 8 weeks and 16 weeks of age. Bmp3 deletion was confirmed using X-gal staining in P0 animals. Cartilage and bone tissue were examined in P14 animals using Alcian Blue/Alizarin Red staining. Detailed long bone analysis was performed in 8-week-old and 16-week-old animals using micro-CT. The Bmp3 reporter signal was localized in bone tissue, hair follicles, and lungs. Bone mineralization at 2 weeks of age was increased in long bones of Bmp3^−/− mice. Bmp3 deletion was shown to affect the skeleton until adulthood, where increased cortical and trabecular bone parameters were found in young and adult mice of both sexes, while delayed mineralization of the epiphyseal growth plate was found in adult Bmp3^−/− mice.

Evaluation of bone grafting for treatment of low-grade chondrosarcoma of long bones

OBJECTIVE

To retrospectively analyze the biological compatibility and oncologic outcomes of autogenous, allogeneic, or combined bone grafting.

METHODS

From April 2000 to December 2016, 37 patients with histologically confirmed low-grade intramedullary chondrosarcoma of the long bones at Kyungpook National University Hospital were enrolled in this retrospective study. All 37 patients underwent intralesional curettage (with or without cryotherapy) followed by bone grafting. Among the 24 patients who underwent cryotherapy, 13 were treated by prophylactic internal fixation (10 in the femur, 1 in the tibia, and 2 in the humerus). Thirteen patients underwent the same treatment without cryotherapy, whereas 12 did not undergo preventive internal fixation.

RESULTS

A single intraoperative fracture was managed by plate fixation. One patient who underwent cryotherapy and internal fixation developed a fracture distal to the operation site 25 days after surgery, and this fracture was repaired with a long plate. None of the 37 patients showed any recurrence or metastasis.

CONCLUSIONS

Adequate intralesional curettage (with or without cryosurgery) combined with bone grafting using autogenous and allogeneic bone chips was effective for the treatment of low-grade intramedullary chondrosarcoma. Therefore, prophylactic internal fixation using a plate is recommended in the cryotherapy of definite cortical invasion in weight-bearing bones.

Evaluating for Racial Differences in Pain Management of Long-Bone Fractures in a Pediatric Rural Population

OBJECTIVES

The aim of this study was to determine if a racial disparity exists in the administration of an analgesic, time to receiving analgesic, and type of analgesic administered to children with long-bone fractures. Prior studies have reported the existence of racial disparity but were mostly in adult and urban populations.

METHODS

This is a retrospective chart review of 727 pediatric patients (aged 2-17 years) with International Classification of Diseases, Ninth Revision (or 10th revision) codes for long-one fractures in an emergency department that cares for a suburban and rural population between January 2013 and January 2016. Logistic regression was used to estimate the odds ratio of receiving no analgesic versus receiving an analgesic and receiving a nonopioid versus opioid drug. Linear regression analysis was performed to study the relationship between race and time to receive the analgesic, after adjusting for sex, age, insurance type, and mechanism of injury.

RESULTS

Of the 727 children, 27% of them did not receive analgesics regardless of race. 27% (164/605) of white children, 25% (8/31) of African American children, and 24% (12/49) of Hispanic children did not receive analgesics. African Americans are 12% more likely (odds ratio [OR], 1.12; 95% confidence interval [CI], 0.48-2.61) to receive an analgesic compared with whites, and Hispanics are 22% more likely (OR, 1.22; 95% CI, 0.60-2.45) to receive an analgesic than whites. African Americans are 26% less likely (OR, 0.74; 95% CI, 0.31-1.75) to receive an opioid versus a nonopioid compared with whites, and Hispanics are 92% more likely (OR, 1.92; 95% CI, 0.91-4.17). Mean wait time across all races was 69 minutes, with no statistical difference between groups.

CONCLUSIONS

This study showed no statistical significance in the receipt or type of analgesic or wait time for pediatric long-bone fractures between race in a major academic level 1 trauma children's hospital, despite previous literature citing otherwise. This study augments to the few studies conducted in a rural setting. It is also one of the few studies that analyzed pain management in a large pediatric population as well as used waiting time to receive analgesic as an outcome measure. Overall, we found a mean wait time of 69 minutes for analgesic administration regardless of race, suggesting the need for more prompt pain management across all races for the management of long-bone fracture in the pediatric population.

Magnetic Resonance Imaging Signal Changes Mimicking Bone Metastasis in Patients Receiving Bisphosphonate Therapy

Bisphosphonates are inorganic pyrophosphate agents that reduce bone turnover. These agents reduce bone pain and delay skeletal complications, such as fractures in patients with metastatic lytic lesions, malignant-related hypercalcemia, multiple myeloma, Paget’s disease of bone, and osteoporosis. Osteonecrosis, developing in the jaw bones specifically, has been described as a complication associated with the use of bisphosphonates. In this report, we presented osteonecrosis-like magnetic resonance imaging findings that can be confused with bone metastasis in two patients who underwent long-term bisphosphonate treatment and the value of bone scan and ¹⁸flor-fluorodeoxyglucose positron emission tomography/computerized tomography in the differential diagnosis.

Histiocytic Sarcoma Arising From a Long Bone: Report of Two Cases

Histiocytic sarcoma is a rare, but aggressive malignant neoplasm of monocyte/macrophage lineage with a wide age distribution. Bone involvement is exceedingly rarer compared to the lymph node, skin, and soft tissue, and no long bone involvement has been reported in the English literature. We here report 2 cases of histiocytic sarcoma involving the long bone: one from the femur of a 77-year-old female, status post the placement of an intramedullary nail for subtrochanteric hip fracture; the other from the radius of a 3-year-old female with no significant medical history. Radiologic imaging showed highly destructive lesions in both cases with soft-tissue extension. Microscopy in both cases showed sheets of polygonal mononuclear cells with abundant eosinophilic cytoplasm, prominent nucleoli, and frequent mitosis. Hemophagocytosis were also identified. Immunohistochemistry showed that the lesional cells were strongly diffusely positive for CD68 and CD163. The first patient deteriorated rapidly, despite the aggressive treatment of amputation and chemotherapy. However, the second patient is disease free 36 months post the treatment of amputation only. We conclude that the long bone could be the primary site of histiocytic sarcoma. Its prognosis could be very variable and it is difficult to predict its behavior based on morphological evaluation only.

Can CRP Levels Predict Infection in Presumptive Aseptic Long Bone Non-Unions? A Prospective Cohort Study

Nonunion remains a major complication of the management of long bone fractures. The primary aim of the present study was to investigate whether raised levels of C-reactive protein (CRP) and white blood cell count (WBC), in the absence of clinical signs, are correlated with positive intraoperative tissue cultures in presumptive aseptic long-bone nonunions. Infection was classified as positive if any significant growth of microorganisms was observed from bone/tissue samples sent from the theater at the time of revision surgery. Preoperatively all patients were investigated with full blood count, white blood count differential as well as C-reactive protein (CRP). A total of 105 consecutive patients (59 males) were included in the study, with an average age of 46.76 years (range 16-92 years) at the time of nonunion diagnosis. The vast majority were femoral (56) and tibial (37) nonunions. The median time from the index surgical procedure to the time of nonunion diagnosis was 10 months (range 9 months to 10 years). Positive cultures revealed a mixed growth of microorganisms, with coagulase-negative Staphylococcus (56.4%) being the most prevalent microorganism, followed by Staphylococcusaureus (20.5%). Pseudomonas, Methicillin-Resistant Staphylococcus aureus (MRSA), coliforms and micrococcus were present in the remainder of the cases (23.1%). Overall, the risk of infection with normal CRP levels (<10 mg/L) was 21/80 = 0.26. Elevated CRP levels (≥10 mg/L) increased the risk of infection to 0.72. The relative risk given a positive CRP test was RR = 0.72/0.26 = 2.74. Overall, the WBC count was found to be an unreliable marker to predict infection. Solid union was achieved in all cases after an average of 6.5 months (3-24 months) from revision surgery. In patients with presumed aseptic long bone nonunion and normal CRP levels, the risk of underlying low-grade indolent infection can be as high as 26%. Patients should be made aware of this finding, which can complicate their treatment course and outcomes.

Guided bone tissue regeneration using a hollow calcium phosphate based implant in a critical size rabbit radius defect

Long bone fractures are common and sometimes difficult to treat. Autologous bone (AB), bovine bone and calcium phosphates are used to stimulate bone growth with varying results. In the present study, a calcium phosphate cement (CPC) that previously showed promising grafting capabilities was evaluated for the first time in a long bone defect. A radius defect of 20 mm was created in twenty rabbits. The defect was filled by either a hollow CPC implant that had been previously manufactured as a replica of a rabbit radius through indirect 3D printing, or by particulate AB as control. Defect filling and bone formation was evaluated after 12 weeks by combining micro computed tomography (μCT) and scoring of 3D images, together with histomorphometry and histology. The μCT and histomorphometric evaluations showed a similar amount of filling of the defect (combining graft and bone) between the CPC and AB group, but the scoring of 3D images showed that the filling in the CPC group was significantly larger. Histologically the AB graft could not be distinguished from the new bone. The AB treated defects were found to be composed of more bone than the CPC group, including reorganised cancellous and cortical bone. Both the CPC and AB material was associated with new bone formation, also in the middle of the defect, which could result in closing of the otherwise critically sized gap. This study shows the potential for an indirectly 3D printed implant in guided bone regeneration in critically sized long bone defects.

Ontogenetic and morphological variation in primate long bones reflects signals of size and behavior

OBJECTIVES

Many primates change their locomotor behavior as they mature from infancy to adulthood. Here we investigate how long bone cross-sectional geometry in Pan, Gorilla, Pongo, Hylobatidae, and Macaca varies in shape and form over ontogeny, including whether specific diaphyseal cross sections exhibit signals of periosteal adaptation or canalization.

MATERIALS AND METHODS

Diaphyseal cross sections were analyzed in an ontogenetic series across infant, juvenile, and adult subgroups. Three-dimensional laser-scanned long bone models were sectioned at midshaft (50% of biomechanical length) and distally (20%) along the humerus and femur. Traditional axis ratios acted as indices of cross-sectional circularity, while geometric morphometric techniques were used to study cross-sectional allometry and ontogenetic trajectory.

RESULTS

The humeral midshaft is a strong indicator of posture and locomotor profile in the sample across development, while the mid-femur appears more reflective of shifts in size. By comparison, the distal diaphyses of both limb elements are more ontogenetically constrained, where periosteal shape is largely static across development relative to size, irrespective of a given taxon's behavior or ecology.

DISCUSSION

Primate limb shape is not only highly variable between taxa over development, but at discrete humeral and femoral diaphyseal locations. Overall, periosteal shape of the humeral and femoral midshaft cross sections closely reflects ontogenetic transitions in behavior and size, respectively, while distal shape in both bones appears more genetically constrained across intraspecific development, regardless of posture or size. These findings support prior research on tradeoffs between function and safety along the limbs.

Study on the Long Bone Failure Behaviors Under the Indenter Rigid-Contact by Experiment Analysis and Subject-Specific Simulation

The bending fracture behaviors of long bone have gained great attention due to the high bending fracture risk during sports events, traffic accidents, and falling incidents, etc. For evaluating bone bending behaviors, most of the previous studies used an indenter in three point bending experiments while the effect of its rigidity was never considered. In this work, using the porcine long bones, the three point bending tests were conducted to explore the bone fracture behaviors under a rigid indenter. In addition to collecting the force applied, the bone fracture dynamic process was recorded by high-speed photography, and the fracture surface profile in mesoscale was observed by the scanning electron microscope (SEM). Based on CT scanning of long bones, the cross section properties of test specimens were calculated by a homemade matlab script for correlating with their failure strengths. Also, a subject-specific finite element (FE) model was developed to identify the outcomes induced by a rigid indenter on simulation. Findings led to conclusions as follows: (1) The tension fracture came with fracture path deflection, which was caused by the bone indentation induced mesoscale crack-opening. Due to this damage before the whole bone fracture, a bone fracture moment correction was established to compensate experimental data. (2) The plastic indentation caused the force fluctuation as suggested by correlation analysis. (3) The bone failure moment correlated with the inertial moment of the bone cross section at the fracture location higher than the traditional cross section area. (4) In the subject-specific simulation, the indentation caused compression fracture under a much lower failure force. Removing the element erosion on the indenter-contacted area only during the validation was verified as a good option to solve this issue.

Different Responsiveness of Alveolar Bone and Long Bone to Epithelial-Mesenchymal Interaction-Related Factor

Alveolar bone is both morphologically and functionally different from other bones of the axial or peripheral skeleton. Because of its sensitive nature to external stimuli including mechanical stress, bone loss stimuli, and medication-related osteonecrosis of the jaw, alveolar bone rendering is seen as an important factor in various dental surgical processes. Although multiple studies have validated the response of long bone to various factors, how alveolar bone responds to functional stimuli still needs further clarification. To examine the characteristics of bone in vitro, we isolated cells from alveolar, femur, and tibia bone tissue. Although primary cultured mouse alveolar bone-derived cells (mABDCs) and mouse long bone-derived cells (mLBDCs) exhibited similar osteoblastic characteristics, morphology, and proliferation rates, both showed distinct expression of neural crest (NC) and epithelial-mesenchymal interaction (EMI)-related genes. Furthermore, they showed significantly different mineralization rates. RNA sequencing data demonstrated distinct transcriptome profiles of alveolar bone and long bone. Osteogenic, NC-, and EMI-related genes showed distinct expression between mABDCs and mLBDCs. When the gene expression patterns during osteogenic differentiation were analyzed, excluding several osteogenic genes, NC- and EMI-related genes showed different expression patterns. Among EMI-related proteins, BMP4 elevated the expression levels of osteogenic genes, Msx2, Dlx5, and Bmp2 the most, more noticeably in mABDCs than in mLBDCs during osteogenic differentiation. In in vivo models, the BMP4-treated mABDC group showed massive bone formation and maturation as opposed to its counterpart. Bone sialoprotein expression was also validated in calcified tissues. Overall, our data suggest that alveolar bone and long bone have different responsiveness to EMI by distinct gene regulation. In particular, BMP4 has critical bone formation effects on alveolar bone, but not on long bone. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Reliability of S.A.R.A. (sterilization and reimplantation autograft) technique in long bone open fractures

The reimplantation of small or large extruded bone segments is one of the most complex clinical management scenarios in the treatment of open fractures. No consensus exists regarding the efficiency of this technique. The aim of the study was to analyse the clinical and radiological outcomes of Sterilization and Reimplantation Autograft (S.A.R.A.) technique in open fractures. Therefore, fifteen skeletally mature patients with Gustilo-Anderson -IIIB type fractures treated with autograft reimplantation, were included in this study. The sample size was divided in two groups: patients with a loss of small segments (Group A - less than 5 cm) and those with large segments (Group B - greater than 5 cm). Eight patients belonged to Group A and seven to Group B. The treatment of contaminated bone may be performed by the following protocols: saline rinse, povidone-iodine scrub and saline rinse, retain periosteum, immersion in antibiotic solution (clindamycin and gentamicin and metronidazole), washing with physiological solution, acute reimplantation in Group A or reimplantation after 21 days in Group B after a bone freezing at -80°C. The Radiographic Union Score (RUS), pain visual analogic score (VAS), patient satisfaction and return to work were assessed at a mean follow-up of 24 months. No cases of superficial or deep infection were reported at 2-year follow-up. The fractures achieved a complete union in 14 patients; one patient belonging to Group A had a malabsorption of the replanted bone. Furthermore, povidone-iodine scrub, antibiotic solution immersion, and washing with physiological solution preserved the articular surface morphology. This study suggests that reimplantation of extruded short or long segments may represent a reliable alternative to amputation in open long bone fractures. Further studies are needed to define the most efficient technique for sterilizing the bone autograft to reduce the complication rate.

Increase in the Number of Bone Marrow Osteoclast Precursors at Different Skeletal Sites, Particularly in Long Bone and Jaw Marrow in Mice Lacking IL-1RA

Recently, it was shown that interleukin-1β (IL-1β) has diverse stimulatory effects on different murine long bone marrow osteoclast precursors (OCPs) in vitro. In this study, interleukin-1 receptor antagonist deficient (Il1rn^-/-) and wild-type (WT) mice were compared to investigate the effects of enhanced IL-1 signaling on the composition of OCPs in long bone, calvaria, vertebra, and jaw. Bone marrow cells were isolated from these sites and the percentage of early blast (CD31^hi Ly-6C^-), myeloid blast (CD31⁺ Ly-6C⁺), and monocyte (CD31^- Ly-6C^hi) OCPs was assessed by flow cytometry. At the time-point of cell isolation, Il1rn^-/- mice showed no inflammation or bone destruction yet as determined by histology and microcomputed tomography. However, Il1rn^-/- mice had an approximately two-fold higher percentage of OCPs in long bone and jaw marrow compared to WT. Conversely, vertebrae and calvaria marrow contained a similar composition of OCPs in both strains. Bone marrow cells were cultured with macrophage colony stimulating factor (M-CSF) and receptor of NfκB ligand (RANKL) on bone slices to assess osteoclastogenesis and on calcium phosphate-coated plates to analyze mineral dissolution. Deletion of Il1rn increased osteoclastogenesis from long bone, calvaria, and jaw marrows, and all Il1rn^-/- cultures showed increased mineral dissolution compared to WT. However, osteoclast markers increased exclusively in Il1rn^-/- osteoclasts from long bone and jaw. Collectively, these findings indicate that a lack of IL-1RA increases the numbers of OCPs in vivo, particularly in long bone and jaw, where rheumatoid arthritis and periodontitis develop. Thus, increased bone loss at these sites may be triggered by a larger pool of OCPs due to the disruption of IL-1 inhibitors.

A Contemporary View of the Definition and Diagnosis of Osteoporosis in Children and Adolescents

The last 2 decades have seen growing recognition of the need to appropriately identify and treat children with osteoporotic fractures. This focus stems from important advances in our understanding of the genetic basis of bone fragility, the natural history and predictors of fractures in chronic conditions, the use of bone-active medications in children, and the inclusion of bone health screening into clinical guidelines for high-risk populations. Given the historic focus on bone densitometry in this setting, the International Society for Clinical Densitometry published revised criteria in 2013 to define osteoporosis in the young, oriented towards prevention of overdiagnosis given the high frequency of extremity fractures during the growing years. This definition has been successful in avoiding an inappropriate diagnosis of osteoporosis in healthy children who sustain long bone fractures during play. However, its emphasis on the number of long bone fractures plus a concomitant bone mineral density (BMD) threshold ≤ -2.0, without consideration for long bone fracture characteristics (eg, skeletal site, radiographic features) or the clinical context (eg, known fracture risk in serious illnesses or physical-radiographic stigmata of osteoporosis), inappropriately misses clinically relevant bone fragility in some children. In this perspective, we propose a new approach to the definition and diagnosis of osteoporosis in children, one that balances the role of BMD in the pediatric fracture assessment with other important clinical features, including fracture characteristics, the clinical context and, where appropriate, the need to define the underlying genetic etiology as far as possible.

Design and Optimization Lattice Endoprosthesis for Long Bones: Manufacturing and Clinical Experiment

The article is devoted to the construction of lattice endoprosthesis for a long bone. Clinically, the main idea is to design a construction with the ability to improve bone growth. The article presents the algorithm for such a design. The construction should be produced by additive manufacturing. Such an approach allows using not only metallic materials but also ceramics and polymers. The algorithm is based on the influence function as a method to describe the elementary cell geometry. The elementary cell can be described by a number of parameters. The influence function maps the parameters to local stress in construction. Changing the parameters influences the stress distribution in the endoprosthesis. In the paper, a bipyramid was used as an elementary cell. Numerical studies were performed using the finite element method. As a result, manufacturing construction is described. Some problems for different orientations of growth are given. The clinical test was done and histological results were presented.

Transient osteomyelitis of the distal radius in a three-year-old patient

Aim Reporting on an atypical case of a three-year-old patient affected by osteomyelitis of the distal radius, completely healed without antibiotic therapy. Methods The clinical case is related to a three-year-old patient, whose clinical picture began with fever, pain and swelling of the right wrist. After three days, fever and swelling disappeared, but pain persisted. Plain x-rays of the right wrist, hematologic analyses, magnetic resonance imaging (MRI) with contrast medium and biopsy were performed in order to make a differential diagnosis between acute osteomyelitis and a malignant neoplasm, i.e. Ewing's sarcoma. Results The plain x-rays of the right wrist showed an osteolytic area of the distal radio, with blurred rim. Haematology showed high erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP); MRI confirmed the presence of a lesion, of no certain origin, therefore a biopsy was done. The histology was that of an inflammatory tissue. The patient, after the biopsy, was completely asymptomatic, ESR and CRP were back to normal. Before starting antibiotic therapy, it was preferred repeating x-rays. From the latter, the osteolysis completely disappeared. On the basis of the x-rays, blood exam and symptomatology, it was decided not to submit the patient to any treatment. After two years, the patient never had similar episodes. Conclusion Patient presented with all characteristics of an osteomyelitis of distal radius, was unexpectedly spontaneously healed, without antibiotic therapy. Two years after the onset of the disease the patient recovered without clinical and radiographic sequelae. No similar cases are found in the literature .

Comparative occurrence pattern of fractures in cattle and buffaloes

Background and Aim:

Dairy animals play an important role in the Indian economy. Knowledge of the occurrence pattern of long bone fractures in bovine may help in strategizing the possibilities of treatment and prognosis. This study aimed to find out the comparative occurrence pattern of fractures in cattle and buffaloes.

Materials and Methods:

A total of 278 fractures of bovine (171 in cattle and 107 in buffaloes), presented to the Department of Veterinary Surgery and Radiology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India, during a study of 1 year, were investigated for the occurrence pattern, in relation to species, age, body weight, gender, bone involved, type of fracture (closed or open), and the presentation of bovine as standing or in recumbent state.

Results:

The overall hospital occurrence of fractures in bovine was 4.24% and most of the fractures resulted from slipping and falling on hard floor. Of 278 fractures, the majority (90.28%) involved long bones (n=251; 103 buffaloes and 148 cattle). Forelimb fractures were recorded more common in buffaloes (64.08%), whereas the cattle suffered more of hind limb fractures (60.23%). Cattle also included 11 cases of bilateral fractures of metacarpal (n=3), tibia (n=1), radius and ulna (n=1), and mandible (n=6). Fracture of olecranon constituted 6.83% (n=19) and majority (n=15) were in buffaloes. The cattle had higher percent of open fractures (54.38%) as compared to that in buffaloes (17.76%). Marginally higher percentage of cattle (33.33%) suffering from fracture were recumbent as compared to buffaloes (23.36%) and femur fractures were found to be a leading cause of recumbency (100% in cattle and 75.00% in buffaloes).

Conclusion:

Species-specific differences in the occurrence pattern of fractures exist among cattle and buffaloes. Cattle are found to be more susceptible (1.5 times) to fractures as compared to buffaloes. The buffaloes are vulnerable to forelimb fractures while the cattle to the hind limb. As compared to forelimb, long bone fractures of hind limb are more commonly associated with recumbency in bovine. Cattle are more prone to mandible fractures and the open fractures of long bones as compared to buffaloes.

Commercially available antibiotic-laden PMMA-covered locking nails for the treatment of fracture-related infections - A retrospective case analysis of 10 cases

Introduction: Fracture-related infections (FRIs) are a devastating complication. FRIs are challenging and should be addressed with a multidisciplinary approach. An FRI should be addressed surgically by non-viable bone debridement, local antibiotic deposition, minimization of dead space and fracture stabilization. Antibiotic-laden PMMA-covered nails are a viable option to face these complications. To demonstrate the safety and utility of commercially available antibiotic-laden PMMA-covered nails, we performed a review of the cases operated in our institution and a cost analysis to compare the cost of a commercial nail to other available alternatives.

Material and methods: We designed a retrospective study of consecutive cases to demonstrate the safety and efficacy of antibiotic-laden PMMA-covered commercial nails and designed a cost analysis of commercial coated nails compared to other custom-made alternatives.

Results: We treated seven tibias and three femurs. Nine patients fully fit the criteria for FRI. There was one case of reintervention because of persistent drainage. All fractures healed, and in the first year post-intervention, there were no signs or symptoms of infection. There were no complications related to the commercially available nail that was used. There is a small increase in the direct quantifiable cost in commercially available nails, but non-quantifiable cost should be assessed individually.

Conclusions: Commercially available antibiotic-laden PMMA-covered nails are a safe and useful treatment option for complicated cases of lower limb long bone reconstruction. The low complication rate and the straightforward technique compensate for the direct cost increase in most situations.

In ovo injection of flavanone on bone quality characteristics, biochemical parameters and antioxidant enzyme status of blood in daily chicks

In ovo injection (IOI) of Naringin (N), flavanone was examined on post-hatch blood biochemical parameters, antioxidant status and bone characteristics. Fertile eggs (n = 700) were distributed in seven groups with 100 eggs. On 14th and 17.5th days of incubation, four groups were injected using 15 or 30 mg active ingredient levels of naringin/0.5 ml saline/egg, low and high level, into amnion sac. Controls include sham (injected normal saline, 0.5 ml/egg on day 14 and 17.5th) and un-injected group. IOI of high naringin and saline on 14th day of incubation resulted in lower hatchability and then higher mortality in last week of embryonic life. On day hatch, high levels of injected groups more body weight compared to the control. Chick length was increased at high levels of naringin on day 17.5th compared to control and saline injected. Quality traits of bones were improved in naringin-injected groups compared to control. IOI of naringin influenced thyroid hormones on 14th day of incubation. Naringin groups influenced the Alkaline phosphatase (ALP), Calcium (Ca), superoxide dismutase (SOD), blood biochemical and lipids. Totally, amniotic IOI of naringin in last days of developing embryo may be useful for hatched chick, development of leg long bone or effect on biochemical metabolites by levels of flavanone that it needs more research.

Biomechanical Study of the Development of Long Bones: Finite Element Structure Synthesis of the Human Second Proximal Phalanx Under Growth Conditions

Torsional loads are a possible mechanical explanation for the architecture of long bone. Finite element structure synthesis (FESS) has previously successfully been used as a deductive technique using Wolff's Law by applying expected loads to an unspecific homogeneous solid and eliminating stress free parts to verify muscle forces. The extended approach presented in this article includes further mechanobiological rules to model the development from a cartilage model to a finger bone. In contrast to former computational models, simulation of processes leading to both external growth and internal differentiation are included. Combined axial and torsional loads synthesize a complete human secondary proximal phalanx model comparable to form and internal structure to that observed in vivo. While the computational model is very sensitive to initial alterations of loads, changes after growth have a minor effect as observed in animal models. Predictions of cartilage growth and ossification during FESS showed significant similarities to ontogeny indicating the importance of mechanical factors for the morphogenesis of bone during growth. Anat Rec, 302:1389-1398, 2019. © 2018 Wiley Periodicals, Inc.

3D quantitative comparative analysis of long bone diaphysis variations in microanatomy and cross-sectional geometry

Long bone inner structure and cross-sectional geometry display a strong functional signal, leading to convergences, and are widely analyzed in comparative anatomy at small and large taxonomic scales. Long bone microanatomical studies have essentially been conducted on transverse sections but also on a few longitudinal ones. Recent studies highlighted the interest in analyzing variations of the inner structure along the diaphysis using a qualitative as well as a quantitative approach. With the development of microtomography, it has become possible to study three-dimensional (3D) bone microanatomy and, in more detail, the form-function relationships of these features. This study focused on the selection of quantitative parameters to describe in detail the cross-sectional shape changes and distribution of the osseous tissue along the diaphysis. Two-dimensional (2D) virtual transverse sections were also performed in the two usual reference planes and results were compared with those obtained based on the whole diaphysis analysis. The sample consisted in 14 humeri and 14 femora of various mammalian taxa that are essentially terrestrial. Comparative quantitative analyses between different datasets made it possible to highlight the parameters that are strongly impacted by size and phylogeny and the redundant ones, and thus to estimate their relevance for use in form-function analyses. The analysis illustrated that results based on 2D transverse sections are similar for both sectional planes; thus if a strong bias exists when mixing sections from the two reference planes in the same analysis, it would not problematic to use either one plane or the other in comparative studies. However, this may no longer hold for taxa showing a much stronger variation in bone microstructure along the diaphysis. Finally, the analysis demonstrated the significant contribution of the parameters describing variations along the diaphysis, and thus the interest in performing 3D analyses; this should be even more fruitful for heterogeneous diaphyses. In addition, covariation analyses showed that there is a strong interest in removing the size effect to access the differences in the microstructure of the humerus and femur. This methodological study provides a reference for future quantitative analyses on long bone inner structure and should make it possible, through a detailed knowledge of each descriptive parameter, to better interpret results from the multivariate analyses associated with these studies. This will have direct implications for studies in vertebrate anatomy, but also in paleontology and anthropology.

Comparative study of anxiety and depression following maxillofacial and orthopedic injuries. Study from a Nigerian University Teaching Hospital

This study hopes to compare levels of anxiety and depression in the maxillofacial and orthopedic injured patients over a period of 12 weeks. This was a prospective, repeated measure design. A total of 160 participants (80 with maxillofacial and 80 with long bone fractures) had repeated review follow-ups within 1 week of arrival in the hospital (Time 1), 4-8 weeks after initial contact (Time 2) and 10-12 weeks thereafter (Time 3), using hospital anxiety and depression scale questionnaire. Road traffic accident remained the main cause of injury in both groups of subjects. The Hospital anxiety and Depression scale detected 42 (52.5%) cases of depression at baseline, 36 (47.4%) cases at Time 2, and 14 (18.4%) cases at Time 3 in the maxillofacial injured group. In the long bone fracture subjects, 47 (58.8%) cases were depressed at baseline, 23(33.3%) cases at Time 2, and only 5 (7.2%) cases at Time 3. Both groups showed reduction in depression levels with time. Fifty-six (70.0%) had anxiety at baseline, 32 (42.1%) at Time 2, and only 9 (11.8%) had anxiety at Time 3 in the maxillofacial fracture group, whereas in the long bone fracture group, 69 (86.3%) subjects were anxious at baseline, 32 (46.4%) at Time 2, and 22 (31.9%) at Time 3. There were significant differences in depression and anxiety level in both the maxillofacial and the long bone fracture subjects at baseline (Time 1), Time 2(4-8 weeks) and Time 3(10-12 weeks).

Treatment of pathological fractures of the long bones

Bone metastases of the long bones often lead to pain and pathological fractures. Local treatment consists of radiotherapy or surgery. Treatment strategies are strongly based on the risk of the fracture and expected survival.

Diagnostic work-up consists of CT and biopsy for diagnosis of the primary tumour, bone scan or PET-CT for dissemination status, patient history and blood test for evaluation of general health, and biplanar radiograph or CT for evaluation of the involved bone.

A bone lesion with an axial cortical involvement of >30 mm has a high risk of fracturing and should be stabilised surgically.

Expected survival should be based on primary tumour type, performance score, and presence of visceral and cerebral metastases.

Radiotherapy is the primary treatment for symptomatic lesions without risk of fracturing. The role of post-operative radiotherapy remains unclear.

Main surgical treatment options consist of plate fixation, intramedullary nails and (endo) prosthesis. The choice of modality depends on the localisation, extent of involved bone, and expected survival. Adjuvant cement should be considered in large lesions for better stabilisation.

Cite this article: Willeumier JJ, van der Linden YM, van de Sande MAJ, Dijkstra PDS. Treatment of pathological fractures of the long bones. EFORT Open Rev 2016;1:136–145. DOI: 10.1302/2058-5241.1.000008.

Human autologous mesenchymal stem cells with extracorporeal shock wave therapy for nonunion of long bones

BACKGROUND

Currently, the available treatments for long bone nonunion (LBN) are removing of focus of infection, bone marrow transplantation as well as Ilizarov methods etc. Due to a high percentage of failures, the treatments are complex and debated. To develop an effective method for the treatment of LBN, we explored the use of human autologous bone mesenchymal stems cells (hBMSCs) along with extracorporeal shock wave therapy (ESWT).

MATERIALS AND METHODS

Sixty three patients of LBN were subjected to ESWT treatment and were divided into hBMSCs transplantation group (Group A, 32 cases) and simple ESWT treatment group (Group B, 31 cases).

RESULTS

The patients were evaluated for 12 months after treatment. In Group A, 14 patients were healed and 13 showed an improvement, with fracture healing rate 84.4%. In Group B, eight patients were healed and 13 showed an improvement, with fracture healing rate 67.7%. The healing rates of the two groups exhibited a significant difference (P < 0.05). There was no significant difference for the callus formation after 3 months treatment (P > 0.05). However, the callus formation in Group A was significantly higher than that in the Group B after treatment for 6, 9, and 12 months (P < 0.05).

CONCLUSION

Autologous bone mesenchymal stems cell transplantation with ESWT can effectively promote the healing of long bone nonunions.

Long bone non-unions treated with the diamond concept: a case series of 64 patients

The aim of this retrospective study with prospectively documented data was to report the clinical results of treatment of long bone non-unions using the "diamond concept". Over a 4-year period, patients that presented with a long bone non-union and were managed with the diamond conceptual framework of bone repair were evaluated. Exclusion criteria were hypertrophic, pathological, and infected non-unions. Fixation was revised as it was indicated whilst biological enhancement included the implantation of RIA graft, BMP-7 and concentrated bone marrow aspirate. Data recorded included patient demographics, initial fracture pattern and type of stabilisation, number of previous interventions, time to reoperation, time to union and functional outcome. Painless full weight bearing defined clinical union. Radiological union was defined as the presence of mature callous bridging to at least 3 bone cortices. The minimum follow up was 12 months (range 12-32). In total 64 patients (34 males) with a mean age of 45 years (17-83) were evaluated. Anatomical distribution of non-unions included the femur (54.68%), tibia (34.38%), humerus (4.68%), radius (3.13%) and clavicle (3.13%). The median number of previous interventions was 1 (range 1-5). The majority of patients (82.62%) underwent revision of fixation whereas only bone grafting was performed 9.38% of patients. Three patients developed superficial wound infection (one was MRSA), 1 had deep vein thrombosis and 1 developed heterotopic bone formation. Union was successful in 63/64 (98.4%) non-unions at a mean time of 6 months (range 3-12). All patients were mobilising pain free and returned to their daily living activities at the final follow up. The application of the "diamond concept" in this cohort of patients was associated with a high union rate by providing an optimal mechanical and biological environment. Such an approach should be considered in the surgeon's armamentarium particularly in such cases where difficulty of bone repair is foreseen.

Development of a Radiographic Union Score for Determining Osteotomy Union Rates in Long Bones of the Foot

Determining the status of bone healing after osteotomy can be challenging and has implications ranging from clinical decision-making to standardization of research outcomes without the use of computed tomography. To date, no method has been validated for determining osseous healing of an osteotomy site of the long bones of the foot. The purpose of the present study was to develop a radiographic union scoring system that would enhance the diagnostic healing assessment. We adapted existing orthopedic scales that had been validated for healing in the leg for application in the long bones of the foot. One hundred cases were evaluated by 6 blinded assessors to test the inter- and intrarater reliability of the subjective healing assessment compared with the proposed scoring system. The radiographs were classified by postoperative period: ≤4, 5 to 12, and >12 weeks. The proposed scale had a high interrater reliability but was burdensome. Using a priori item reduction protocols, the scale was limited to the 5 items with the best internal consistency, which significantly reduced the burden. The result was excellent interrater reliability (α = 0.87) among all assessors compared with acceptable reliability (α = 0.66) for the subjective osteotomy healing assessment. The intrarater reliability during the subsequent retest phase demonstrated similar relationships, with low agreement (r = 0.38) for subjective healing. Each of the items included in the final scoring scale had moderate to good agreement across all assessors (r = 0.51 to 0.63). The reliability of this system appeared superior to the subjective assessment of osseous healing alone, even in the absence of clinical correlates after an osteotomy in the foot.

A removable hybrid robot system for long bone fracture reduction

In traditional long bone fracture reduction surgery, there are some drawbacks such as low accuracy, high radiation for surgeons and a risk of infection. To overcome these disadvantages, a removable hybrid robot system is developed, which integrates a removable series-parallel mechanism with a motor-double cylinder (MDC) driven mode. This paper describes the mechanism in detail, analyses the principle and the method of the fracture reduction, presents the surgical procedure, and verifies the reduction accuracy by experiments with bone models. The results are shown as follows. The mean deviations of the axial displacement and lateral displacement are 1.60mm and 1.26 mm respectively. The standard deviations are 0.69 mm and 0.30 mm. The mean deviations of the side angle and turn inward are 2.06° and 2.22° respectively. The standard deviations are 0.50° and 0.99°. This minimally invasive robot features high accuracy and zero radiation for surgeons, and is able to conduct fracture reduction for long bones.

High abundance of CD271(+) multipotential stromal cells (MSCs) in intramedullary cavities of long bones

Aspiration of iliac crest bone marrow (ICBM) remains the most frequent technique used in harvesting multipotential stromal cells (MSCs) for bone regeneration. Although this tissue type is easily accessed by a surgeon, it has a low frequency of MSCs, which is significant given the high cell numbers required for bone regeneration strategies. Lipoaspirates possess higher MSC frequencies, albeit cells with a differentiation profile less suited to orthopaedic interventions. Intra-medullary cavities of long bones have previously been shown to harbour MSCs in animals, however evaluation of their frequency, differentiation capacity and phenotype in humans had not previously been performed. Long bone fatty bone marrow (LBFBM) was collected prior to harvesting bone graft. Basic cellular compositions of donor-matched LBFBM and ICBM aspirates, including the numbers of CD34(+) hematopoietic stem cells and CD31(+) endothelial cells, were similar. MSCs were enumerated using colony-forming-unit-fibroblast assays and flow cytometry for the presence of a resident LBFBM CD45(-/low) CD271(+) MSC population and revealed a trend for higher MSC numbers (average 5 fold, n=6) per millilitre of LBFBM compared to donor-matched ICBM. Functional characteristics of resident MSCs, including their growth rates, differentiation potentials and surface phenotypes (CD73(+)CD105(+)CD90(+)) before and after culture-amplification, were similar. Enhanced numbers of MSCs could be recovered following brief enzymatic treatment of solid fragments of LBFBM. Our findings therefore reveal that the intramedullary cavity of the human femur is a depot of MSCs, which, although closely associated with fat, have a differentiation profile equivalent to ICBM. This anatomical site is frequently accessed by the orthopaedic/trauma surgeon and aspiration of the intramedullary cavity represents a 'low-tech' method of harvesting potentially large numbers of MSCs for regenerative therapies and research.

Cytological diagnosis of adamantinoma of long bone in a 78-year-old man

A clinicohistopathological study of a rare case of adamantinoma of long bone in a 78-year-old patient is presented. The cytological features when evaluated in conjunction with clinical and radiologic features are sufficiently diagnostic. The primary knowledge of its existence and knowledge of its cytological features are important for a correct preoperative cytological diagnosis.

Developmental and genetic origins of murine long bone length variation

If we wish to understand whether development influences the rate or direction of morphological evolution, we must first understand the developmental bases of morphological variation within species. However, quantitative variation in adult morphology is the product of molecular and cellular processes unfolding from embryonic development through juvenile growth to maturity. The Atchley-Hall model provides a useful framework for dissecting complex morphologies into their component parts as a way of determining which developmental processes contribute to variation in adult form. We have examined differences in postnatal allometry and the patterns of genetic correlation between age-specific traits for ten recombinant inbred strains of mice generated from an intercross of LG/J and SM/J. Long bone length is closely tied to body size, but variation in adult morphology is more closely tied to differences in growth rate between 3 and 5 weeks of age. These analyses show that variation generated during early development is overridden by variation generated later in life. To more precisely determine the cellular processes generating this variation we then examined the cellular dynamics of long bone growth plates at the time of maximum elongation rate differences in the parent strains. Our analyses revealed that variation in long bone length is the result of faster elongation rates of the LG/J stain. The developmental bases for these differences in growth rate involve the rate of cell division and chondrocyte hypertrophy in the growth plate.

Jaw and long bone marrows have a different osteoclastogenic potential

Osteoclasts, the multinucleated bone-resorbing cells, arise through fusion of precursors from the myeloid lineage. However, not all osteoclasts are alike; osteoclasts at different bone sites appear to differ in numerous respects. We investigated whether bone marrow cells obtained from jaw and long bone differed in their osteoclastogenic potential. Bone marrow cells from murine mandible and tibiae were isolated and cultured for 4 and 6 days on plastic or 6 and 10 days on dentin. Osteoclastogenesis was assessed by counting the number of TRAP(+) multinucleated cells. Bone marrow cell composition was analyzed by FACS. The expression of osteoclast- and osteoclastogenesis-related genes was studied by qPCR. TRAP activity and resorptive activity of osteoclasts were measured by absorbance and morphometric analyses, respectively. At day 4 more osteoclasts were formed in long bone cultures than in jaw cultures. At day 6 the difference in number was no longer observed. The jaw cultures, however, contained more large osteoclasts on plastic and on dentin. Long bone marrow contained more osteoclast precursors, in particular the myeloid blasts, and qPCR revealed that the RANKL:OPG ratio was higher in long bone cultures. TRAP expression was higher for the long bone cultures on dentin. Although jaw osteoclasts were larger than long bone osteoclasts, no differences were found between their resorptive activities. In conclusion, bone marrow cells from different skeletal locations (jaw and long bone) have different dynamics of osteoclastogenesis. We propose that this is primarily due to differences in the cellular composition of the bone site-specific marrow.