Aim: The aim of the study was to investigate the influence of bone density of the greater tuberosity on
Background: The stability of fracture fixation is influenced by the type of fixation, densitometric and geometric structure of the bone. DXA measures the integral mass of trabecular and cortical bone mineral but cannot discriminate between the structurally and mechanically separate constitutes. Distribution and organisation of bone mass (the geometric structure) has the final determination of the mechanical properties of bone. Pq CT scan is able to measure densitometric and geometric parameters of bone structure. However, there are no reports in the literature on the relationship between these measurements and the strength of fracture fixation. Our aim is to study the correlation between geometric and densitometric measurements of Pq CT scan, with the strength of fixation of bicondylar tibial plateau fractures and to assess the role of both trabecular and cancellous bone in that strength. Method: Eight Fresh frozen human cadaveric tibias were collected from subjects without a medical history of skeletal pathology. The proximal 10% of the tibia was scanned in a peripheral quantitative computer tomography scanner 1mm thick transverse slides, the cancellous and cortical bone mineral density of the proximal tibia were measured. The geometrical parameters: cortical area, trabecular area, bone strength index (BSI) and the Stress strain index (SSI) as non invasive indicators of the
Aim: Retears after rotator cuff surgery occur frequently and may compromise the functional results. Failure of bone anchors and sutures may influence the results to a great part. The goals of this in vitro investigation were to determine the
Antibiotic-laden bone cement is an important strategy of treatment for an established bone infection. It was aimed to find the safe antibiotic dose intervals of the antibiotic cements soaked in Phosphate Buffered Saline solution and to determine whether there was a difference in terms of
Osteoporosis accounts for a leading cause of degenerative skeletal disease in the elderly. Osteoblast dysfunction is a prominent feature of age-induced bone loss. While microRNAs regulate osteogenic cell behavior and bone mineral acquisition, however, their function to osteoblast senescence during age-mediated osteoporosis remains elusive. This study aims to utilize osteoblast-specific microRNA-29a (miR-29a) transgenic mice to characterize its role in bone cell aging and bone mass. Young (3 months old) and aged (9 months old) transgenic mice overexpressing miR-29a (miR-29aTg) driven by osteocalcin promoter and wild-type (WT) mice were bred for study. Bone mineral density, trabecular morphometry, and biomechanical properties were quantified using μCT imaging, material testing system and histomorphometry. Aged osteoblasts and senescence markers were probed using immunofluorescence, flow cytometry for apoptotic maker annexin V, and RT-PCR. Significantly decreased bone mineral density, sparse trabecular morphometry (trabecular volume, thickness, and number), and poor biomechanical properties (maximum force and breaking force) along with low miR-29a expression occurred in aged WT mice. Aging significantly upregulated the expression of senescence markers p16INK4a, p21Waf/Cip1, and p53 in osteoporotic bone in WT mice. Of note, the severity of bone mass and biomechanical strength loss, as well as bone cell senescence, was remarkably compromised in aged miR-29aTg mice. In vitro, knocking down miR-29a accelerated senescent (β-galactosidase activity and senescence markers) and apoptotic reactions (capsas3 activation and TUNEL staining), but reduced mineralized matrix accumulation in osteoblasts. Forced miR-29a expression attenuated inflammatory cytokine-induced aging process and retained osteogenic differentiation capacity. Mechanistically, miR-29a dragged osteoblast senescence through targeting 3′-untranslated region of anti-aging regulator FoxO3 to upregulate that of expression as evident from luciferase activity assessment. Low miR-29a signaling speeds up aging-induced osteoblast dysfunction and osteoporosis development. Gain of miR-29a function interrupts osteoblast senescence and shields bone tissue from age-induced osteoporosis. The robust analysis sheds light to the protective actions of miR-29a to skeletal metabolism and conveys a perspective of miR-29a signaling enhancement beneficial for aged skeletons.
We have studied the mechanical properties of several current techniques of tendon-to-bone suture employed in rotator-cuff repair. Non-absorbable braided polyester and absorbable polyglactin and polyglycolic acid sutures best combined ultimate tensile strength and stiffness. Polyglyconate and polydioxanone sutures failed only at high loads, but elongated considerably under moderate loads. We then compared the mechanical properties of nine different techniques of tendon grasping, using 159 normal infraspinatus tendons from sheep. The most commonly used simple stitch was mechanically poor: repairs with two or four such stitches failed at 184 N and 208 N respectively. A new modification of the Mason-Allen suture technique improved the ultimate tensile strength to 359 N for two stitches. Finally, we studied the mechanical properties of several methods of anchorage to bone using typically osteoporotic specimens. Single and even double transosseous sutures and suture anchor fixation both failed at low tensile loads (about 140 N). The use of a 2 mm thick, plate-like augmentation device improved the failure strength to 329 N. The mechanical properties of many current repair techniques are poor and can be greatly improved by using good materials, an improved tendon-grasping suture, and augmentation at the bone attachment.
A population based finite element study that accounts for subject-specific morphology, density and load variations, suggests that osteoporosis does not markedly lower the mechanical compliance of the proximal femur to routine loads. Osteoporosis (OP) is a bone disease defined by low bone density and micro-architectural deterioration. This deterioration is neither uniform nor symmetric at the proximal femur. Evidence from analyses performed at the tissue level suggests that the cortical shell at the femoral neck is thinner in OP patients, especially in the superior regions, but not in the infero-anterior ones [Poole, Rubinacci]. Analogously, OP femurs show a higher anisotropy of the trabecular bone than controls [Ciarelli], suggesting a preservation of load bearing capacity in the principal loading direction vs. the transverse one. There is general consensus that the regions subjected to higher loads during walking, which is the predominant motor activity in the elderly, are mostly preserved. All these findings suggest that the OP femur should exhibit an almost normal mechanical competence during daily activities. This would be in accordance with the very low incidence of spontaneous fractures [Parker] and with the moderate fracture predictivity of BMD. Although reasonable, this hypothesis has never been tested at the organ level. Aim of the present study was to verify it with a population-based finite element (FE) study.Summary Statement
Introduction
Comparison of two cementing techniques: femoral component insertion into early-cure stage cement and insertion into late-cure stage cement in an in vivo model to identify if cement cure stage affects the strength of the bone cement interface. Bilateral arthroplasties – using only the femoral component - were performed in vivo on paired porcine femora. The femora were harvested and cross-sectioned in preparation for strength testing. Performance was measured by peak load required to push the femoral prosthesis and surrounding cement mantle free of the cancellous bone. The mean failure load for prostheses inserted into late cure stage cement was 908 N +/− SD 420, whereas the mean failure load for the conjugate early cure stage cement was 503 N +/− SD 342. A paired t-test indicated significantly higher load failure rates in the late cure stage cement versus the early cure stage samples (t=2.37, p<
0.049). Femoral component insertion into late cure stage cement required statistically significant higher loads for push-out when compared to femoral component insertion into early cure stage cement.
The use of fresh morsellised allograft in impaction bone grafting for revision hip surgery remains the gold standard. Bone marrow contains osteogenic progenitor cells that arise from multipotent mesenchymal stem cells and we propose that in combination with allograft will produce a living composite with biological and mechanical potential. This study aimed to determine if human bone marrow stromal cells (HBMSC) seeded onto highly washed morsellised allograft could survive the impaction process, differentiate and proliferate along the osteogenic lineage and confer biomechanical advantage in comparison to impacted allograft alone. Future work into the development of a bioreactor is planned for the potential safe translation of such a technique into clinical practice.
Total leg muscle function in hip OA patients is not well studied. We used a test-retest protocol to evaluate the reproducibility of single- and multi-joint peak muscle torque and rapid torque development in a group of 40–65 yr old hip patients. Both peak torque and torque development are outcome measures associated with functional performance during activities of daily living. Patients: Twenty patients (age 55.5±3.3, BMI 27.6±4.8) who underwent total hip arthroplasty participated in this study. Reliability: We used the intra-class correlation (ICC) and within subject coefficients of variation (CVws) to evaluate reliability. Agreement: Relative Bland-Altman 95% limits of agreements (LOA) and smallest detectable difference (SDD) were calculated and used for evaluation of measurement accuracy. Parameters: Maximal muscle strength (peak torque, Nm) and rate of torque development (Nm•sec-1) for affected (AF) and non-affected (NA) side were measured during unilateral knee extension-flexion (seated), hip extension-flexion, and hip adduction-abduction (standing), respectively. Contractile RTD100, 200, peak was derived as the average slope of the torque-time curve (torque/time) at 0–100, 0–200 and 0 peak relative to onset of contraction. Protocol: After 5 min level walking at self-selected and maximum speeds each muscle group was tested using 1–2 sub-maximal contraction efforts followed by 3 maximal contractions 4s duration. Statistics: The variance components were estimated using STATA12, with muscle function and occasion as independent variable and patients as random factor, using the restricted maximum likelihood method (=0.05).Introduction
Material and Methods
Aims. Orthopaedic surgery requires grafts with sufficient
Aims. Limited implant survival due to aseptic cup loosening is most commonly responsible for revision total hip arthroplasty (THA). Advances in implant designs and materials have been crucial in addressing those challenges. Vitamin E-infused highly cross-linked polyethylene (VEPE) promises strong wear resistance, high oxidative stability, and superior
To address the current challenge of anterior cruciate ligament (ACL) reconstruction, this study is the first to fabricate a braided collagen rope (BCR) which mimics native hamstring for ACL reconstruction. The study aims to evaluate the biological and biomechanical properties of BCR both in vivo and vitro. Rabbit ACL reconstruction model using collagen rope and autograft (hamstring tendon) was conducted. The histological and biomechanical evaluations were conducted at 6-, 12-, 18, 26-week post-operation. In vitro study included cell morphology analysis, cell function evaluation and RNA sequencing of the tenocytes cultured on BCR. A cadaver study was also conducted to verify the feasibility of BCR for ACL reconstruction. BCR displays satisfactory
Aims. To develop an early implant instability murine model and explore the use of intermittent parathyroid hormone (iPTH) treatment for initially unstable implants. Methods. 3D-printed titanium implants were inserted into an oversized drill-hole in the tibiae of C57Bl/6 mice (n = 54). After implantation, the mice were randomly divided into three treatment groups (phosphate buffered saline (PBS)-control, iPTH, and delayed iPTH). Radiological analysis, micro-CT (µCT), and biomechanical pull-out testing were performed to assess implant loosening, bone formation, and osseointegration. Peri-implant tissue formation and cellular composition were evaluated by histology. Results. iPTH reduced radiological signs of loosening and led to an increase in peri-implant bone formation over the course of four weeks (timepoints: one week, two weeks, and four weeks). Observational histological analysis shows that iPTH prohibits the progression of fibrosis. Delaying iPTH treatment until after onset of peri-implant fibrosis still resulted in enhanced osseointegration and implant stability. Despite initial instability, iPTH increased the mean pull-out strength of the implant from 8.41 N (SD 8.15) in the PBS-control group to 21.49 N (SD 10.45) and 23.68 N (SD 8.99) in the immediate and delayed iPTH groups, respectively. Immediate and delayed iPTH increased mean peri-implant bone volume fraction (BV/TV) to 0.46 (SD 0.07) and 0.34 (SD 0.10), respectively, compared to PBS-control mean BV/TV of 0.23 (SD 0.03) (PBS-control vs immediate iPTH, p < 0.001; PBS-control vs delayed iPTH, p = 0.048; immediate iPTH vs delayed iPTH, p = 0.111). Conclusion. iPTH treatment mediated successful osseointegration and increased bone
A spine compression fracture is a very common form of fracture in elderly with osteoporosis. Injection of polymethyl methacrylate (PMMA) to fracture sites is a minimally invasive surgical treatment, but PMMA has considerable clinical risks. We develop a novel type thermoplastic injectable bone substitute contains the proprietary composites of synthetic ceramic bone substitute and absorbable thermoplastic polymer. We used thermoplastic biocompatible polymers Polycaproactone (PCL) to encapsulate calcium-based bone substitutes hydroxyapatite (Ca10(PO4)6(OH)2, HA) and tricalcium phosphate (TCP) to form a biodegradable injectable bone composite material. The space occupation ration PCL:HA/TCP is 1:9. After heating process, it can be injected to fracture site by specific instrument and then self-setting to immediate reinforce the vertebral body. The thermoplastic injection bone substitute can obtain good injection properties after being heated by a heater at 90˚C for three minutes, and has good anti-washout property when injected into normal saline at 37˚C. After three minutes, solidification is achieved. Mechanical properties were assessed using the material compression test system and the mechanical support close to the vertebral spongy bone. In vitro cytotoxicity MTT assay (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) was performed and no cell cytotoxicity was observed. In vivo study with three New Zealand rabbits was performed, well bone growth into bone substitute was observed and can maintain good mechanical support after three months implantation. The novel type thermoplastic injection bone substitute can achieve (a) adequate injectability and viscosity without the risk of cement leakage; (b) adequate
In 2021 the bone grafting market was worth €2.72 billion globally. As allograft bone has a limited supply and risk of disease transmission, the demand for synthetic grafting substitutes (BGS) continues to grow while allograft bone grafts steadily decrease. Synthetic BGS are low in
Residual tumor cells left in the bone defect after malignant bone tumor resection can result in local tumor recurrence and high mortality. Therefore, ideal bone filling materials should not only aid bone reconstruction or regeneration, but also exert local chemotherapeutic efficacy. However, common bone substitutes used in clinics are barely studied in research for local delivery of chemotherapeutic drugs. Here, we aimed to use facile manufacturing methods to render polymethylmethacrylate (PMMA) cement and ceramic granules suitable for local delivery of cisplatin to limit bone tumor recurrence. Porosity was introduced into PMMA cement by adding 1-4% carboxymethylcellulose (CMC) containing cisplatin, and chemotherapeutic activity was rendered to two types of granules via adsorption. Then, mechanical properties, porosity, morphology, drug release kinetics, ex vivo reconstructive properties of porous PMMA and in vitro anti-cancer efficacy against osteosarcoma cells were assessed. Morphologies, molecular structures, drug release profiles and in vitro cytostatic effects of two different drug-loaded granules on the proliferation of metastatic bone tumor cells were investigated. The
We developed a novel silorane-based biomaterial (SBB) for use as an orthopedic cement. SBB is comprised of non-toxic silicon-based monomers, undergoes non-exothermic polymerization, and has weight-bearing strength required of orthopedic cements. We sought to compare the antibiotic release kinetics of this new cement to that of commercially available PMMA bone cement. We also evaluated each material's inherent propensity to support the attachment of bacteria under both static and dynamic conditions. One gram of either rifampin or vancomycin was added to 40g batches of PMMA and SBB. Pellets were individually soaked in PBS. Eluate was collected and tested daily for 14 days using HPLC. Compressive strength and modulus were tested over 21 days. Bioassays were used to confirm the bioactivity of the antibiotics eluted. We measured the growth and maturation of staphylococcus aureus (SA) biofilm on the surface of both PMMA and SBB disks over the course of 72 hours in a static well plate and in a dynamic biofilm reactor (CDC Biofilm Reactor). N=4 at 24, 48, and 72 hours. A luminescent strain of SA (Xen 29) was employed allowing imaging of bacteria on the discs. SBB eluted higher concentrations of vancomycin than did PMMA over the course of 14 days (p<0.001). A significant 55.1% greater day 1 elution was observed from SBB. Silorane cement was able to deliver rifampin in clinically favorable concentrations over 14 days. On the contrary, PMMA was unable to deliver rifampin past day 1. The incorporation of rifampin into PMMA severely reduced its
Aim. Prosthetic joint infections pose a major clinical challenge. Developing novel material surface technologies for orthopedic implants that prevent bacterial adhesion and biofilm formation is essential. Antimicrobial coatings applicable to articulating implant surfaces are limited, due to the articulation mechanics inducing wear, coating degradation, and toxic particle release. Noble metals are known for their antimicrobial activity and high
Varus malalignment increases the susceptibility of cartilage to mechanical overloading, which stimulates catabolic metabolism to break down the extracellular matrix and lead to osteoarthritis (OA). The altered mechanical axis from the hip, knee to ankle leads to knee joint pain and ensuing cartilage wear and deterioration, which impact millions of the aged population. Stabilization of the remaining damaged cartilage, and prevention of further deterioration, could provide immense clinical utility and prolong joint function. Our previous work showed that high tibial osteotomy (HTO) could shift the mechanical stress from an imbalanced status to a neutral alignment. However, the underlying mechanisms of endogenous cartilage stabilization after HTO remain unclear. We hypothesize that cartilage-resident mesenchymal stem cells (MSCs) dampen damaged cartilage injury and promote endogenous repair in a varus malaligned knee. The goal of this study is to further examine whether HTO-mediated off-loading would affect human cartilage-resident MSCs' anabolic and catabolic metabolism. This study was approved by IACUC at Xi'an Jiaotong University. Patients with medial compartment OA (52.75±6.85 yrs, left knee 18, right knee 20) underwent open-wedge HTO by the same surgeons at one single academic sports medicine center. Clinical data was documented by the Epic HIS between the dates of April 2019 and April 2022 and radiographic images were collected with a minimum of 12 months of follow-up. Medial compartment OA with/without medial meniscus injury patients with unilateral Kellgren /Lawrence grade 3–4 was confirmed by X-ray. All incisions of the lower extremity healed well after the HTO operation without incision infection. Joint space width (JSW) was measured by uploading to ImageJ software. The Knee injury and Osteoarthritis Outcome Score (KOOS) toolkit was applied to assess the pain level. Outerbridge scores were obtained from a second-look arthroscopic examination. RNA was extracted to quantify catabolic targets and pro-inflammatory genes (QiaGen). Student's t test for two group comparisons and ANOVA analysis for differences between more than 2 groups were utilized. To understand the role of mechanical loading-induced cartilage repair, we measured the serial changes of joint space width (JSW) after HTO for assessing the state of the cartilage stabilization. Our data showed that HTO increased the JSW, decreased the VAS score and improved the KOOS score significantly. We further scored cartilage lesion severity using the Outerbridge classification under a second-look arthroscopic examination while removing the HTO plate. It showed the cartilage lesion area decreased significantly, the full thickness of cartilage increased and
Objectives. The objective of this study was to characterize the effect of rifampin incorporation into poly(methyl methacrylate) (PMMA) bone cement. While incompatibilities between the two materials have been previously noted, we sought to identify and quantify the cause of rifampin’s effects, including alterations in curing properties,
Anterior cruciate ligament (ACL) reconstruction is the current standard of care for ACL tears. However, the results are not consistently successful, autografts or allografts have certain disadvantages, and synthetic grafts have had poor clinical results. The aim of this study was to determine the efficacy of tissue engineering decellularized tibialis tendons by recellularization and culture in a dynamic tissue bioreactor. To determine if recellularization of decellularized tendons combined with mechanical stimulation in a bioreactor could replicate the mechanical properties of the native ACL and be successfully used for ACL reconstruction in vivo. Porcine tibialis tendons were decellularized and then recellularized with human adult bone marrow-derived stem cells. Tendons were cultured in a tissue bioreactor that provided biaxial cyclic loading for up to 7 days. To reproduce mechanical stresses similar to hose experienced by the ACL within the knee joint, the tendons were subjected to simultaneous tension and torsion in the bioreactor. Expression of tendon-specific genes, and newly synthesized collagen and glycosaminoglycan (GAG) were used to quantify the efficacy of recellularization and dynamic bioreactor culture. The
Background. Tigecycline, the first member of glycylcycline family, has effective antimicrobial activity against resistant and implant associated infectious organisms. The objectives of this study are to assess the compressive and tensile
Objective: The purpose of the present study was to assess whether clinicians are actually able to evaluate the mechanical status of lengthening callus from plain radiographs. Materials and Methods: 36 rats were employed in this study. Their left femurs were lengthened by 6 mm as a bone lengthening model. Rats were euthanized at 4 8 12 and 16 weeks after lengthening. Both femora were X-rayed and then bone density parameters (bone mineral content, bone mineral density and bone area) of lengthening callus were measured using pQCT. Three-point bending test was performed to determine the
Current strategy for orthopedic tissue engineering mainly focusses on the regeneration of the damaged tissue using cell-seeded three-dimensional scaffolds. Biocompatible scaffolds with controllable degradation and suitable mechanical property are required to support new tissue in-growth and regeneration . [1]. Porous composite scaffolds made from organic and inorganic materials are highly preferred, which can mimic the natural bone in their composition as well can enhance tissue repair . [2]. Scaffolds with optimum
Objectives. The objective of this study was to determine if combining variations in mixing technique of antibiotic-impregnated polymethylmethacrylate (PMMA) cement with low frequency ultrasound (LFUS) improves antibiotic elution during the initial high phase (Phase I) and subsequent low phase (Phase II) while not diminishing
Introduction: Since Albright first proposed the concept of diabetic osteopenia, many studies have investigated the levels of mineral bone density (BMD) and risk of osteoporosis. In this study we investigate the effect of exercise, alfacalcidol and parathyroid hormone (1–34) on bone marker, BMD and bone mechanical properties in spontaneously diabetic GK/Jcl rats. Methods: 18 week-old male GK/Jcl rats were divided into 4 groups; no treatment (NT), exercise (Ex), alfacalcidol (ALF), and parathyroid hormone (PTH). The bone mineral density (BMD) of the lumbar vertebrae (L2-L4) and the left femur was measured by dual energy X-ray absorptiometry (DXA). Serum calcium (Ca), inorganic phosphorus (Pi) and osteocalcin (OC) were measured. Urinary Ca, Po, and creatinine (Cre) were measured. Urinary deoxypyridinoline (D-Pyr) was measured and the data were corrected for urinary Cre concentration.
Background. Antibiotic-loaded cement has been used over decades as a local antibiotic delivery for the treatment of bone and joint infections. However, there were some disadvantages such as unpredictable elution, insufficient local concentration and reduced
As compared to magnesium (Mg) and iron (Fe), solid zinc (Zn)-based absorbable implants show better degradation rates. An ideal bone substitute should provide sufficient mechanical support, but pure Zn itself is not strong enough for load-bearing medical applications. Modern processing techniques, like additive manufacturing (AM), can improve
After anterior cruciate ligament (ACL) rupture, reconstructive surgery with a hamstring tendon autograft is often performed. Despite overall good results, ACL re-rupture occurs in up to 10% of the patient population, increasing to 30% of the cases for patients aged under 20 years. This can be related to tissue remodelling in the first months to years after surgery, which compromises the graft's
Aims. To determine whether half-threaded screw holes in a new titanium locking plate design can substantially decrease the notch effects of the threads and increase the plate fatigue life. Methods. Three types (I to III) of titanium locking plates were fabricated to simulate plates used in the femur, tibia, and forearm. Two copies of each were fabricated using full- and half-threaded screw holes (called A and B, respectively). The
Treatment of tendon and ligament injuries remains challenging; the aim is to find a biocompatible substance with mechanical and structural properties that replicate those of normal tendon and ligament. We examined the mechanical properties of Demineralised Cortical Bone (DCB) after gamma irradiation (GI) and freeze drying (FD). We also used different techniques for repairing bone-tendon-bone with DCB in order to measure the mechanical performance of the construct. DCB specimens were allocated into 4 groups; FD, GI, combination of both or none. The maximum tensile forces and stresses were measured. 4 cadaveric models of repair of 1cm patellar tendon defect using DCB were designed; model-1 using one bone anchor, Model-2 using 2 bone anchors, Model-3 off-loading by continuous thread looped twice through bony tunnels, Model-4 off-loading with 3 hand braided threads. Force to failure and mode were recorded for each sample. FD groups results were statistically higher (p=<0.05) compared to non-FD groups, while there was no statistical difference between GI and non-GI groups. The median failure force for model-1: 250N, model-2: 290N, model-3: 767N and model-4: 934N. There was no statistical significance between model-1 and model-2 (p=0.249), however statistical significance was found between other models (p=<0.006). GI has no significant effect on
Introduction: Impaction allografting allows an initial stable function of revision hip replacements and a method of reconstituting the bone stock. A previous in-vivo ovine study has found that the density of impacted morsellised allograft reduces after six weeks but recovers by twelve weeks. This reduction in density during remodelling may also correspond with a reduced
Background. External fixation is a method of osteosynthesis currently required in traumatology and orthopaedic surgery. Pin tract infection is a common problem in clinical practice. Infection occurs after a bacterial colonisation of the pin due to its contact with skin and local environment. To prevent such local contamination, one way to handle this issue is to create a specific coating using method which could be applied in the medical field. In this work we develop a surface coating for external fixator pins based on photocatalytic TiOα properties, producing a bactericidal effect with sufficient
Summary Statement. We evaluated the
We studied the calcium content and
Introduction The AO/ASIF 3.5 mm STS is increasingly used for internal fixation of large bones with the recent introduction of the 3.5 mm periarticular plating system. Our study aims to compare the insertion torque and mechanical properties of the screw after insertion into bovine femora using non tapped and pretapped methods. Methods Three groups of ten 3.5 mm AO/ASIF STSs of variable lengths were used. One group was put aside as the control. One group was inserted into fresh bovine femora using pre-tapped drill holes and the final group using non-tapped drill holes. The insetion torques were measured and compared using an analogue torque screw driver. All screws were removed. The three groups were then tested for
Adult articular cartilage mechanical functionality is dependent on the unique zonal organization of its tissue. Current mesenchymal stem cell (MSC)-based treatment has resulted in sub-optimal cartilage repair, with inferior quality of cartilage generated from MSCs in terms of the biochemical content, zonal architecture and
Patellar fractures account for approximately 1% of all fractures. Open reduction and internal fixation is recommended to restore extensor continuity and articular congruity. However, complications such as nonunion and symptomatic hardware, still exist. Furthermore, there is a risk of re-fracturing of the healed bone during the removal of the implants. Magnesium (Mg), a biodegradable metal, has elastic moduli and compressive yield strength that are comparable to those of natural bone. Our previous study showed that released Mg ions enhanced fracture healing. However, Mg-based implants degrade rapidly after implantation and lead to insufficient
Objectives. Bisphosphonates (BP) are the first-line treatment for preventing fragility fractures. However, concern regarding their efficacy is growing because bisphosphonate is associated with over-suppression of remodelling and accumulation of microcracks. While dual-energy X-ray absorptiometry (DXA) scanning may show a gain in bone density, the impact of this class of drug on mechanical properties remains unclear. We therefore sought to quantify the
Summary Statement. This study describes the design and preliminary in vitro testing of a novel patch for the repair of rotator cuff tendon tears. The laminated design incorporates woven and electrospun components. The woven element provides the patch with excellent
Biometals like Magnesium (Mg) and Zinc (Zn) are essential for life. Mg/Zn-deficiency has been linked to numerous diseases including cardiovascular, bone, diabetics, neurological and neurodegenerative disorders. Moreover, Mg/Zn-based biomaterials have recently emerged as innovative degradable medical implants, typically for cardiovascular and orthopedic application. We study the pathophysiological role of Mg. 2+. /Zn. 2+. ion in vascular and bone diseases, as well as metallic Mg/Zn alloys for stent and bone implant applications. We demonstrated some interesting role and mechanism of Mg. 2+. /Zn. 2+. ion in controlling cellular functions. Also, metallic Mg/Zn-based medical implants exhibited strong potential as stent and bone fixation device. They have sufficient
Introduction. Total Elbow Arthroplasty (TEA) is recognized as an effective treatment solution for patients with rheumatoid arthritis or for traumatic conditions. Current total elbow devices can be divided into linked or unlinked design. The first design usually presents a linking element (i.e. an axle) to link together the ulnar and humeral components to stabilize the joint; the second one does not present any linkage and the stability is provided by both intrinsic design constraints and the soft tissues. Convertible modular solutions allow for an intraoperative decision to link or unlink the prosthesis; the modular connections introduce however additional risks in terms of both
In order to evaluate the feasibility of zinc alloys as future biodegradable bone implant materials, the mechanical properties, corrosion resistance, hemocompatibility, cell activity, proliferation and adhesion, in vivo animal implantation experiments have been employed. The experimental results show that the alloying element magnesium, calcium and strontium can significantly improve the mechanical properties of pure zinc, and further deformation processes can further improve the mechanical properties of zinc alloys. Alloying elements can effectively control the corrosion rates of zinc alloys, which are between the rates of magnesium alloys and iron alloys. Zinc and zinc alloys exhibit excellent hemocompatibility and the hemolysis rate is far lower than 5%. After adding alloying elements Mg, Ca and Sr, MG63 and ECV304 cell proliferation rate and activity increased significantly, while for VSMC cell, the influence of alloying elements effect is not obvious. Zinc alloy intramedullary pins can effectively promote the new bone formation, and after 2 months implanted in mice femur, they still maintained a relatively complete structure, indicating that they are able to provide enough
Biomechanical analysis is important to evaluate the effect of orthopaedic surgeries. CT-image based finite element method (CT-FEM) is one of the most important techniques in the computational biomechanics field. We have been applied CT-FEM to evaluate resorptive bone remodeling, secondary to stress shielding, after total hip arthroplasty (THA). We compared the equivalent stress and strain energy density to postoperative BMD (bone mineral density) change in the femur after THA, and a significant correlation was observed between the rate of changes in BMD after THA and equivalent stress. For periacetabular osteotomy cases, we investigated mechanical stress in the hip joint before and after surgery. Mechanical stress in the hip joint decreased significantly after osteotomy and correlated with the degree of the acetabular coverage. For arthroscopic osteochondroplasty cases, we examined
Collagen is a key component of the extracellular matrix in a variety of tissues and hence is widely used in tissue engineering research, yet collagen has had limited uptake in the field of 3D printing. In this study we successfully adapted an existing electronic printing method, aerosol jet printing (AJP), to print high resolution 3D constructs of recombinant collagen type III (RHCIII). Circular samples with a diameter of 4.5mm and 288 layers thick, or a diameter of 6.5mm and 400 layers thick were printed on glass cover slips with print lines of 60µm. Attenuated Total Reflectance Fourier-Transorm Infa-red (ATR-FTIR) spectroscopy performed on the 4 of the printed samples and dried non-printed RHCIII samples showed that no denaturation had occurred due to the printing process. Printed samples were crosslinked using EDC [N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride, Sigma Aldrich] to improve their stability and
The effect of bisphosphonates on the mechanical properties of the uninjured contra-lateral cortical bone during fracture healing is poorly reported. There remains conflicting evidence with regards the effect of bisphosphonate therapy on cortical bone strength. We assessed the effect of nine weeks of Ibandronate therapy, in a dose known to preserve cancellous bone BMD and strength, on the mechanical properties of the uninjured rat tibial diaphyses using a standardised model of tibial osteotomy and plate fixation. Skeletally mature ex-breeder rats were used. Stress at failure of the tibial diaphyses was measured by a four-point bending test using a custom made jig for rat tibiae. The
Scaffold-based bone tissue engineering holds great promise for the future of osseous defects therapies. Prepare the suitable scaffold properties are physiochemical modifications in terms of porosity,
Balloon kyphoplasty (BKP) is a minimally invasive surgical technique used to correct kyphosis and vertebral compression fractures. BKP uses cement to fill a void created by the inflation of a balloon in a vertebra, it can be used as an alternative to vertebroplasty to reduce cement extravasation. Issues such as poor inter digitisation of the cement and the trabecular bone can arise with the BKP method. This can be due to a compacted layer created during the procedure which can cause complications post-surgery. The primary aim of this study was to investigate alternative cement application methods which could improve the
INTRODUCTION. Electron beam melting is a promising technique to produce surface structures for cementless implants. Biomimetic apatite coatings can be used to enhance bone ingrowth. The goal of this study was to evaluate bone ingrowth of an E-beam produced structure with biomimetic coating and compare this to an uncoated structure and a conventionally made implant surface. METHODS. Implants. The implants (10×4×4mm) were produced with E-beam technology. (Eurocoating). All E-beam implants had a cubic surface structure (porosity 77%). Two structures were coated (Eurocoating), one with hydroxyapatite (cubicHA) and one with brushite (cubicBR). One was left uncoated. A control specimen with a titanium plasma spray coating (TiPS) was also tested. (Figure 1). Experimental design. Surgery was performed on 12 goats. A double set of specimens was implanted in the iliac crest. 4 goats were sacrificed 3 weeks after surgery and 8 goats after 15 weeks. Push out test. The specimens were pushed out the surrounding bone by a Material Testing System (MTS) to define the
Summary. Our results prove that Demineralised Cortical Bone (DCB) can be used as biological tendon graft substitute, combined with correct surgical technique and the use of suture bone anchor early mobilisation can be achieved. Introduction. Surgical repair of tendon injuries aims to restore length,
Purpose. The Birmingham Mid-Head Resection (BMHR) is a bone-conserving, short-stem alternative to hip resurfacing for patients with compromised femoral head anatomy. It is unclear, however, if an uncemented, metaphyseal fixed stem confers a mechanical advantage to that of a traditional hip resurfacing in which the femoral prosthesis is cemented to the prepared femoral head. Thus, we aimed to determine if a metaphyseal fixed, bone preserving femoral component provided superior
Embryonic chick tenocytes cultured in fixed-length three-dimensional fibrin gels synthesise a taught collagen fibril-rich extracellular matrix that closely resembles embryonic tendon (. Kapacee et al., . Matrix Biology. , . 27. : . 371. –375, . 2008. ). Importantly, the cells replace fibrin with parallel arrays of collagen fibrils that are able to resist pulling forces. Regenerative medicine strategies for musculoskeletal applications require the development of tissue with
Objectives. Healing in cancellous metaphyseal bone might be different from
midshaft fracture healing due to different access to mesenchymal
stem cells, and because metaphyseal bone often heals without a cartilaginous
phase. Inflammation plays an important role in the healing of a
shaft fracture, but if metaphyseal injury is different, it is important
to clarify if the role of inflammation is also different. The biology
of fracture healing is also influenced by the degree of mechanical
stability. It is unclear if inflammation interacts with stability-related
factors. Methods. We investigated the role of inflammation in three different models:
a metaphyseal screw pull-out, a shaft fracture with unstable nailing
(IM-nail) and a stable external fixation (ExFix) model. For each,
half of the animals received dexamethasone to reduce inflammation,
and half received control injections. Mechanical and morphometric evaluation
was used. Results. As expected, dexamethasone had a strong inhibitory effect on
the healing of unstable, but also stable, shaft fractures. In contrast,
dexamethasone tended to increase the
The reconstruction of a skeletal defect after resection of a bone tumour represents a challenge for the orthopaedic surgeon. Age, site of the lesion and extension of the disease often limit the choice of surgical technique for a conservative procedure, but several options are available, mainly modular, composite or custom prostheses, massive bone allografts with or without autologous vascularised fibular grafts (AVF), and arthrodeses. An interesting reconstructive technique uses the AVF graft, with microsurgical technique, alone or associated with a massive allograft. The association of a fibular transplant with an allograft increases the
In revision total hip arthroplasty (THA), it is essential to cope with the bone stock loss. The acetabular bone loss is reconstructed by bulk bone grafts, bone chips, bone cement or jumbo cup. The impaction bone-grafting (IBG) technique is a technique that can restore acetabular bone loss, while enough bone allografts are not easy to obtain and the quality is not always sufficient. Thus we mixed hydroxyapatite (HA) granules into bone chips to supplement the volume and the
The December 2023 Trauma Roundup360 looks at: Distal femoral arthroplasty: medical risks under the spotlight; Quads repair: tunnels or anchors?; Complex trade-offs in treating severe tibial fractures: limb salvage versus primary amputation; Middle-sized posterior malleolus fractures – to fix?; Bone transport through induced membrane: a randomized controlled trial; Displaced geriatric femoral neck fractures; Risk factors for reoperation to promote union in 1,111 distal femur fractures; New versus old – reliability of the OTA/AO classification for trochanteric hip fractures; Risk factors for fracture-related infection after ankle fracture surgery.
Aim: Antibiotics are currently used during fracture healing for prevention or treatment of infection. Quinolones are well known to delay fracture healing, but little is known about other antibiotics. Cefazolin is the most commonly used drug for antibiotic prophylaxis, but many centres use cefuroxime. When allergy to cephalosporins is present, current recommendations include clindamicin or vancomicin. The purpose of this study is to know if other commonly used antibiotics can delay fracture healing. Methods: 100 male 3-months-old Wistar rats were used. After anaesthesia with ketolar, a closed fracture in the middle third of the femur was carried out. Rats were divided in five groups (20 rats each): one receiving cefazolin (a first generation cephalosporin, CZ), other receiving cefuroxime (a second generation cephalosporine, CF), other vancomicin (group V), other clindamicin (group CL) and the other receiving placebo (P) for 4 weeks. Group CZ received a subcutaneous dose of 50mg/kg/daily, Group CF received a dose of 100 mg/Kg/daily, Group V received a dose of 20 mg/Kg/daily, Group CL received a dose of 25 mg/Kg/daily and group P received water. 4 weeks later rats were killed and femora extracted. A mechanical test (low speed torsion) was performed to evaluate healing. All four groups (CZ, CF, V, CL) were compared to placebo through ANOVA. Results: Six bones were discarded because of technical errors, no infections were found. The maximum torque achieved by the calluses before breaking were 240 mNm in group P (n=18), 238 in group CZ (n=20), 178 in group CF (n=19), 167 in group V (n=19), and 205 in group CL (n=18). When compared to placebo, cefazolin and clindamicin showed no statistical differences (N.S, p>
0,10), vancomicin had lower callus strength (p=0,015), and cefuroxime had also lower callus strength near the significance level (p=0,084). Conclusion: The
Biodegradable porous scaffolds play an important role in tissue engineering as the temporary templates for transplanted cells to guide the formation of the new organs. The most commonly used porous scaffolds are constructed from two classes of biomaterials. One class consists of synthetic biodegradable polymers such as poly (α-hydroxy acids), poly(glycolic acid), poly(lactic acid), and their copolymer of poly(DL-lactic-co-glycolic acid) (PLGA). The other class consists of naturally derived polymers such as collagen. These biomaterials have their respective advantages and drawbacks. Therefore, hybridization of these biomaterials has been expected to combine their advantages to provide excellent three-dimensional porous biomaterials for tissue engineering. Our group developed one such kind of hybrid biodegradable porous scaffolds by hybridizing synthetic poly (α-hydroxy acids) with collagen. Collagen microsponges were nested in the pores of poly (α-hydroxy acids) sponge to construct the poly (α-hydroxy acids)-collagen hybrid sponge. Observation by scanning electron microscopy (SEM) showed that microsponges of collagen with interconnected pore structures were formed in the pores of poly (α-hydroxy acids) sponge. The
Titanium alloys such as Ti-6Al-4V and Ti-6Al-7Nb have been widely used as orthopedic implants such as artificial hip joint, because of their high
Aims. The purpose of this study was to evaluate the biological fixation of a 3D printed porous implant, with and without different hydroxyapatite (HA) coatings, in a canine model. Materials and Methods. A canine transcortical model was used to evaluate the characteristics of bone ingrowth of Ti6Al4V cylindrical implants fabricated using laser rapid manufacturing (LRM). At four and 12 weeks post-implantation, we performed histological analysis and mechanical push-out testing on three groups of implants: a HA-free control (LRM), LRM with precipitated HA (LRM-PA), and LRM with plasma-sprayed HA (LRM-PSHA). Results. Substantial bone ingrowth was observed in all LRM implants, with and without HA, at both time periods. Bone ingrowth increased from 42% to 52% at four weeks, to 60% to 65% at 12 weeks. Mechanical tests indicated a minimum shear fixation strength of 20 MPa to 24 MPa at four weeks, and 34 MPa to 40 MPa at 12 weeks. There was no significant difference in the amount of bone ingrowth or in the shear strength between the three implant types at either time period. Conclusion. At four and 12 weeks, the 3D printed porous implants exhibited consistent bone ingrowth and high
To test the hypothesis that reseeded anterior cruciate ligament (ACL)-derived cells have a better ability to survive and integrate into tendon extracellular matrix (ECM) and accelerate the ligamentization process, compared to adipose-derived mesenchymal stem cells (ADMSCs). Acellularized tibialis allograft tendons were used. Tendons were randomly reseeded with ACL-derived cells or ADMSCs. ACL-derived cells were harvested and isolated from remnants of ruptured ACLs during reconstruction surgery and cultured at passage three. Cell suspensions (200 µl) containing 2 × 106 ACL-derived cells or ADMSCs were prepared for the purpose of reseeding. At days 1, 3, and 7 post-reseeding, graft composites were assessed for repopulation with histological and immunohistochemical analysis. Matrix protein contents and gene expression levels were analyzed.Aims
Methods
Background. Simply stated, carbon reinforced carbon (C/C) may be considered as fibre reinforced pyrocarbon. Pyrocarbon is used e.g. in finger joints and artificial heart valves. Aim of the present study was to evaluate if C/C could broaden the field of orthopaedic applications compared to pyrocarbon. Technically, C/C is used e.g. for brakes of F-1 race cars. Methods. The
Basic engineering principles dictate that unplugged screw holes serve as sites of the concentration of stress and the initiation and growth of cracks (1,2). The idea of filling the holes were tested previously in the literature showing promising results (3). However there's either adverse results which might be a design mistake (4). The purpose of this study was to determine if the use of specially designed screw hole inserts in empty locking screw holes improves the strength and failure characteristics of locking plates. Forty two 7-hole locking LC/DCP plates were mounted on cylindric UHMW Polyethylene blocks with a 1-cm gap between blocks, simulating a fracture with comminution and bone loss. 21 plates had a screw hole insert placed in the center hole (centered over the simulated fracture), while 21 of the plates remained empty in the center hole. The plate–block constructs were placed in a mechanical testing machine and subjected to a series of loading conditions. The axial, bending and torsional stiffness and displacements needed for failure of each plate-block construct was calculated. The Statistical analysis was performed by Mann Whitney-U test for independent variables. All plates were then loaded to failure. There were significant difference in the axial load to failure (p=0.017), bending load to failure (p<0.01) and bending diplacements (p<0.01) of the test groups favoring the screw hole insert group as a higher
Purpose. Failure resulting from a recurrent infection in total knee arthroplasty (TKA) is a challenging problem. Knee arthrodesis is one treatment option, however fusion is not always successful, as there is huge bone defect. The authors reports a new arthrodesis technique that uses a bundle of flexible intramedullary rods and an antibiotic-loaded cement spacer. Methods. There were 13 cases of arthrodesis due to recurrent periprosthetic joint infection, which were performed by the first author (WS Cho) at Asan Medical Center in Seoul from 2005 to 2014. All previous prosthetic components were removed and cement was thoroughly excised using a small osteotome. Two stage operation was done in most of cases. After thorough debridement, antibiotics loaded cement was inserted in first stage, flexible intramedullary rods were inserted retrogradely in the femoral side with the knee in flexion under fluoroscopy guidance. After filling the femoral intramedullary canal, the rods were then driven back securely into the tibial medullary canal. We aimed for as much rod length as possible to maximize stability. After 6 weeks of first stage operation, the rods of the femoral and tibial sides were arranged such that they overlapped and interdigitated to maximize
Patella fracture after total knee arthroplasty has a variety of etiologies and has been reported to occur with an incidence ranging from 3% to 21%. Heavy patients with full flexion are at greatest risk for sustaining patella fracture. Overstuffing the patellofemoral joint with an oversized femoral component, an anteriorised femoral component or a femoral component placed in excessive extension can also overload the underlying patella. A similar phenomenon may be seen with underrsection of the patella or use of a thick button. Excessive patellar resection can predispose to patellar fracture as well. It has been demonstrated that a residual patella thickness of less than 15 mm can substantially increase anterior patellar strain. Asymmetric patellar resection can also critically alter the
The aim of this study was to investigate the safety and efficacy of 3D-printed modular prostheses in patients who underwent joint-sparing limb salvage surgery (JSLSS) for malignant femoral diaphyseal bone tumours. We retrospectively reviewed 17 patients (13 males and four females) with femoral diaphyseal tumours who underwent JSLSS in our hospital.Aims
Methods
The aim of this study was to compare the migration of the femoral component, five years postoperatively, between patients with a highly cross-linked polyethylene (HXLPE) insert and those with a conventional polyethylene (PE) insert in an uncemented Triathlon fixed insert cruciate-retaining total knee arthroplasty (TKA). Secondary aims included clinical outcomes and patient-reported outcome measures (PROMs). We have previously reported the migration and outcome of the tibial components in these patients. A double-blinded randomized controlled trial was conducted including 96 TKAs. The migration of the femoral component was measured with radiostereometry (RSA) at three and six months and one, two, and five years postoperatively. PROMs were collected preoperatively and at all periods of follow-up.Aims
Methods
In revision total hip replacement, bone loss can be managed by impacting porous bone chips. In order to guarantee sufficient
The December 2023 Foot & Ankle Roundup360 looks at: Subchondral bone cysts remodel after correction of varus deformity in ankle arthritis; 3D-printed modular endoprosthesis reconstruction following total calcanectomy; Percutaneous partial bone excision in the management of diabetic toe osteomyelitis; Hemiepiphysiodesis is a viable surgical option for Juvenile hallux valgus; Ankle arthroplasty vs arthrodesis: which comes out on top?; Patient-related risk factors for poorer outcome following total ankle arthroplasty; The Outcomes in Ankle Replacement Study.
Introduction. In vitro studies showed that the anti-oxidative properties of vitamin E stabilize free radicals while retaining the
The primary objective of this study was to compare the five-year tibial component migration and wear between highly crosslinked polyethylene (HXLPE) inserts and conventional polyethylene (PE) inserts of the uncemented Triathlon fixed insert cruciate-retaining total knee arthroplasty (TKA). Secondary objectives included clinical outcomes and patient-reported outcome measures (PROMs). A double-blinded, randomized study was conducted including 96 TKAs. Tibial component migration and insert wear were measured with radiostereometric analysis (RSA) at three, six, 12, 24, and 60 months postoperatively. PROMS were collected preoperatively and at all follow-up timepoints.Aims
Methods
Porous surfaces on orthopaedic implants have been shown to promote tissue ingrowth. This study evaluated biological fixation of novel additively manufactured porous implants with and without hydroxyapatite coatings in a canine transcortical model. Laser rapid manufacturing (LRM) Ti6Al4V cylindrical implants were built with a random interconnected architecture mimicking cancellous bone (5.2 mm diameter, 10mm length, 50–60% porous, mean pore size 450μm). Three groups were investigated in this study: as-built with no coating (LRM), as-built coated with solution precipitated hydroxyapatite (LRM-PA), and as-built coated with a plasma sprayed hydroxyapatite (LRM-PSHA). Implants were press-fit into a 5mm unicortical, perpendicular drill hole in the femoral diaphysis of the left and right femurs in 12 canines. Right femora were harvested for histology (SEM, bone ingrowth into implant within cortical region) and left femora for mechanical push-out testing (shear strength of bone-implant interface) at 4 and 12 weeks (N=6, un-paired Student's t-test, p=0.05). For mean bone ingrowth, there was no significant difference between groups at 4 weeks (LRM, LRM-PA, LRM-PSHA: 41.5+8.6%, 51+5.5% and 53.2+11%, respectively) or 12 weeks (LRM, LRM-PA, LRM-PSHA: 64.4+2.8%, 59.9+7.6%, 64.9+6.4%, respectively). LRM and LRM-PA implants had more bone ingrowth at 12 weeks than 4 weeks (p < 0 .05). Mean shear strength of all implants at 12 weeks (LRM, LRM-PA, LRM-PSHA: 39.9+3.6MPa, 33.7+4.6MPa, 36+4.1MPa respectively) were greater than at 4 weeks (LRM, LRM-PA, LRM-PSHA: 21.6+2.8MPa, 20.7+1.1MPa, 20.2+2.5MPa respectively) (p < 0 .05). No significant difference was observed between all groups at 4 or 12 weeks. Overall, this canine study confirmed the suitability of this novel additive manufacturing porous material for biological fixation by bone ingrowth. All implants exhibited high bone ingrowth and
Although absorbable sutures for the repair of acute Achilles tendon rupture (ATR) have been attracting attention, the rationale for their use remains insufficient. This study prospectively compared the outcomes of absorbable and nonabsorbable sutures for the repair of acute ATR. A total of 40 patients were randomly assigned to either braided absorbable polyglactin suture or braided nonabsorbable polyethylene terephthalate suture groups. ATR was then repaired using the Krackow suture method. At three and six months after surgery, the isokinetic muscle strength of ankle plantar flexion was measured using a computer-based Cybex dynamometer. At six and 12 months after surgery, patient-reported outcomes were measured using the Achilles tendon Total Rupture Score (ATRS), visual analogue scale for pain (VAS pain), and EuroQoL five-dimension health questionnaire (EQ-5D).Aims
Methods
Cartilage injuries rarely heal spontaneously and often require surgical intervention, leading to the formation of biomechanically inferior fibrous tissue. This study aimed to evaluate the possible effect of amelogenin on the healing process of a large osteochondral injury (OCI) in a rat model. A reproducible large OCI was created in the right leg femoral trochlea of 93 rats. The OCIs were treated with 0.1, 0.5, 1.0, 2.5, or 5.0 μg/μl recombinant human amelogenin protein (rHAM+) dissolved in propylene glycol alginate (PGA) carrier, or with PGA carrier alone. The degree of healing was evaluated 12 weeks after treatment by morphometric analysis and histological evaluation. Cell recruitment to the site of injury as well as the origin of the migrating cells were assessed four days after treatment with 0.5 μg/μl rHAM+ using immunohistochemistry and immunofluorescence.Aims
Methods
The December 2022 Foot & Ankle Roundup360 looks at: Evans calcaneal osteotomy and multiplanar correction in flat foot deformity; Inflammatory biomarkers in tibialis posterior tendon dysfunction; Takedown of ankle fusions and conversion to total ankle arthroplasty; Surgical incision closure with three different materials; Absorbable sutures are not inferior to nonabsorbable sutures for tendo Achilles repair; Zadek’s osteotomy is a reliable technique for treating Haglund’s syndrome; How to best assess patient limitations after acute Achilles tendon injury; Advances in the management of infected nonunion of the foot and ankle.
The effects of remnant preservation on the anterior cruciate ligament (ACL) and its relationship with the tendon graft remain unclear. We hypothesized that the co-culture of remnant cells and bone marrow stromal cells (BMSCs) decreases apoptosis and enhances the activity of the hamstring tendons and tenocytes, thus aiding ACL reconstruction. The ACL remnant, bone marrow, and hamstring tendons were surgically harvested from rabbits. The apoptosis rate, cell proliferation, and expression of types I and III collagen, transforming growth factor-β (Aims
Methods
Several artificial bone grafts have been developed but fail to achieve anticipated osteogenesis due to their insufficient neovascularization capacity and periosteum support. This study aimed to develop a vascularized bone-periosteum construct (VBPC) to provide better angiogenesis and osteogenesis for bone regeneration. A total of 24 male New Zealand white rabbits were divided into four groups according to the experimental materials. Allogenic adipose-derived mesenchymal stem cells (AMSCs) were cultured and seeded evenly in the collagen/chitosan sheet to form cell sheet as periosteum. Simultaneously, allogenic AMSCs were seeded onto alginate beads and were cultured to differentiate to endothelial-like cells to form vascularized bone construct (VBC). The cell sheet was wrapped onto VBC to create a vascularized bone-periosteum construct (VBPC). Four different experimental materials – acellular construct, VBC, non-vascularized bone-periosteum construct, and VBPC – were then implanted in bilateral L4-L5 intertransverse space. At 12 weeks post-surgery, the bone-forming capacities were determined by CT, biomechanical testing, histology, and immunohistochemistry staining analyses.Aims
Methods
Aim. Cementless prosthesis is one of the major bone-implant interface fixation methods in total joint replacement. Grit blasted surface, hydroxyapatite coated surface and plasma sprayed metallic porous coating have been popularly used. The latter has demonstrated higher bone implant mechanical stability in previous laboratory study in early and middle stages. However, question remains what the mechanism is to make it performing better and how to improve them further. This study is designed to examine the mode of failure in bone-implant interface in a sheep model. Method. Plasma sprayed porous coated (TiPL); hydroxyapatite (HA) coated and and grit blasted (TiGB) titanium implants were examined in the study. Each type has 36 specimens. Implants were inserted into cortical bones in a press-fit fashion in a total of 22 sheep bilateral hind limbs. Specimens were retrieved at 4 weeks and 12 weeks. Push- out testing was performed to just reach ultimate failure. Failed bone-implant interface were investigated by histology and BSEM. The percentage of failure at bone-coating interface, bone itself fracture, coating itself failure, and coating-substrate dissociation were measured by BSEM. Results. In TiPL group, failure occurred mainly at new bone itself on ingrowing new bone and adjacent bone, with 74% at 4 weeks, and 82% at 12 weeks. The percentages were significantly higher than that of the failure at bone-porous coating dissociation. Furthermore, the percentage of failure occurred at bone was also higher in TiPS group than in the other groups at both time points. In HA group, the main proportion of failure, 69%, occurred at bone-HA dissociation at 4 weeks, higher than the 25% at bone itself fracture. 57% of failure occurred at HA-substrate dissociation at 12 weeks, which was followed by HA coating itself breakage (Figure 1). Bone itself fracture has the lowest proportion of only 4% breakage at 12 weeks. HA coating revealed micro cracks at some area although not all of them were failed. In TiGB group, failure mainly occurred at bone-implant surface dissociation at both time points. Conclusion. The failure mode at the HA and TiGB groups demonstrate that new bone was less likely to break, or stronger, than bone-implant surface interface at early stage, and new bone at middle stage was stronger than the other interfaces. The bone ingrowth to metallic porous coating results in that major proportion failure has to occur at bone anchorage, either at the entry level or at adjacent bone. The anchorage is the reason why TiPS has higher
Introduction. Vancomycin is commonly added to acrylic bone cement during revision arthroplasty surgery. Proprietary cement preparations containing vancomycin are available but significantly more expensive. We investigated whether the antibiotic elution and
The December 2023 Oncology Roundup360 looks at: A single osteotomy technique for frozen autograft; Complications, function, and survival of tumour-devitalized autografts used in patients with limb-sparing surgery; Is liquid nitrogen recycled bone and vascular fibula the biological reconstruction of choice?; Solitary pulmonary metastases at first recurrence of osteosarcoma; Is a radiological score able to predict resection-grade chondrosarcoma in primary intraosseous lesions of the long bones?; Open versus core needle biopsy in lower-limb sarcoma – current practice patterns and patient outcomes; Natural history of intraosseous low-grade chondroid lesions of the proximal humerus; Local treatment modalities and event-free survival in patients with localized Ewing’s sarcoma; Awaiting biopsy results in solitary pathological proximal femoral fractures.
Bone grafting utilises tissue harvesting from second anatomic location of same patient (autograft) or from a human donor (allograft) to treat bone defects. Limited availability of bone grafts, donor site morbidity and risk of disease transmission led to an alternative strategy for bone grafting as synthetic materials that can promote bone regeneration. Engineered bone grafts are biocompatible and possess sufficient
A novel enhanced cement fixation (EF) tibial implant with deeper cement pockets and a more roughened bonding surface was released to market for an existing total knee arthroplasty (TKA) system.This randomized controlled trial assessed fixation of the both the EF (ATTUNE S+) and standard (Std; ATTUNE S) using radiostereometric analysis. Overall, 50 subjects were randomized (21 EF-TKA and 23 Std-TKA in the final analysis), and had follow-up visits at six weeks, and six, 12, and 24 months to assess migration of the tibial component. Low viscosity bone cement with tobramycin was used in a standardized fashion for all subjects. Patient-reported outcome measure data was captured at preoperative and all postoperative visits.Aims
Methods
This study aims to report the outcomes in the treatment of unstable proximal third scaphoid nonunions with arthroscopic curettage, non-vascularized bone grafting, and percutaneous fixation. This was a retrospective analysis of 20 patients. All cases were delayed presentations (n = 15) or failed nonoperatively managed scaphoid fractures (n = 5). Surgery was performed at a mean duration of 27 months (7 to 120) following injury with arthroscopic debridement and arthroscopic iliac crest autograft. Fracture fixation was performed percutaneously with Kirschner (K)-wires in 12 wrists, a headless screw in six, and a combination of a headless screw and single K-wire in two. Clinical outcomes were assessed using grip strength, patient-reported outcome measures, and wrist range of motion (ROM) measurements.Aims
Methods
Self-locking button-like fixation devices for ACL reconstruction are attracting knee surgeons' attention due to promising technical advantages: complete filling of the tunnel with graft, anatomic reconstruction (AM portal), fixation achievement even when a short tunnel is reamed, opportunity of graft re-tensioning after tibial fixation and/or cyclic load. We compared two similar devices (TightRope vs ToggleLocZL). 20 fresh-frozen porcine femurs (mean age 2.1 years) were assigned to the two groups by randomization. Hamstrings with 9 mm of diameter were obtained using bovine tendons that show the same biomechanic behaviour of human hamstrings. Femoral tunnel was created by AM portal technique (anatomic position). Zwick-Roell z010 tension/compression device with bone and tendon clamps, was used for the study:. Cyclic test (1000 cycles, 0.5 Hz, 50–250 N/cycle, 50 cycles of preload at 10–80 N/cycle). Final pull-out test (1 mm/s). Failure analysis. CT scan and densitometry. Any implant didn't fail during cyclic test. The elongation average was 2.85±1.63 for ToggleLoc and 2.71±.85 for TightRope (P>0.05). Pull-out test showed different values in terms of Ultimate Strength Failure (USF), Stiffness at USF, and Stiffness:. The failure mode was:. The mean method of failure was the fracture of the cortical bone of the femoral condyle, for both groups. But if we extrapolate the USF the difference was favourable(P<0.05) for TightRope (707.83 N) than ToggleLoc (580.16). The mean bone density of porcine femora was comparable to young human femora (1.12±0.31 BMD). The reproducibility of surgical technique, the
Introduction. Recently, the combination of press-fit acetabular cup with ceramic articulation is a widely used for implanting cementless acetabular components and has been shown to provide good initial stability. However, these methods may lead to elevating stresses, changing in the bearing geometries, and increasing wear due to deformation of the cup and insert. In addition, there is a potential for failure of ceramic inserts when a large ball head was used because it should be assembled with shallow thickness of the acetabular cup. For risk reduction of it, we applied direct metal tooling (DMT) based on 3D printing for porous coating on the cup. Due to its capability of
Predictable fracture healing fails to occur in 5–10% of cases. This is particularly concerning among individuals with osteoporosis. With an increasing aging population, one in three women and one in five men above the age of 50 experience fragility fractures. As such, there is a critical need for an effective treatment option that could enhance fracture healing in osteoporotic bone. Lithium, the standard treatment for bipolar disorder, has been previously shown to improve fracture healing through modulation of the Wnt/beta-catenin pathway. We optimised the precise oral lithium administration parameters to improve
There is no question that excellent long-term results have been demonstrated with all-polyethylene tibial components. Moreover, improvements in polyethylene to increase wear resistance, maintain
Background. In young patients with femoral neck non-union it is desirable to preserve the femoral head. The objective of this study was to assess the outcome results of revision internal fixation and nonvascular fibular bone grafting. Patients and Methods:. Ten patients with non united fracture neck femur were included in this prospective study. Fixation was done with two cancellous screws leaving behind a space between two screws for fibular strut graft. Assessment of union was done by both clinical and radiological criteria. Results:. union was achieved in 8 cases in an average time of 16 weeks (range 12–20 weeks). There was no infection, thromboembolic complications, donor site morbidity or implant failure in our series. Conclusion:. Nonvascularized fibular strut graft along with cancellous screws provides a biological and mechanically sound method of treatment. Fibula being cortical provides
Among the very large number of polymeric materials that have been proposed in the field of orthopedics, polyethylene terephthalate (PET) is one of the most attractive thanks to its flexibility, thermal resistance,
Introduction. Corrosion of the femoral head-trunnion junction in modular hip components has become a concern as the corrosion products may lead to adverse local tissue reactions. A simple way to avoid trunnion corrosion is to manufacture the femoral head with a non-metallic material, such as ceramics that are widely. An alternative solution may lie in advanced polymers like polyaryletherketones (PAEKs). These thermoplastics have high
There is no question that excellent long-term results have been demonstrated with all-polyethylene tibial components. Moreover, improvements in polyethylene to increase wear resistance, maintain
Transverse pin femoral fixation of bone-patella tendon-bone (BPTB) in ACL reconstruction has been widely applied during the last decades. Aim of our study is to confront two different system of transverse femoral fixation for BPTB graft: Transfix BTB (Arthrex) and BioTransfix T3 (Arthrex). The main differences between these two system are the diameter (3.0 mm Transfix BTB and 3.5 mm BioTransfix T3), and section (Transfix BTB is cannulated). Surgical technique adopts the same transverse vectorial guide but different guide sleeves. 30 fresh-frozen porcine knees (mean age 2.2 years) were assigned to the two groups randomisedly. the patellar bone block and tendon were harvested using the same size in all specimens (10mm × 25 mm, 10 mm). Zwick-Roell z010 tension/compression device with bone clamps, was used for the study:. Cyclic test (1000 cycles, 0.5 Hz, 50–250 N/cycle, 100 cycles of preload). Final pull-out test (1 mm/s). Failure analysis. CT scan and densitometry. Any implant didn't fail during cyclic test. The elongation average was 1.85±0.63 for Transfix BTB and 1.69±0.87 for BioTransfix T3. Pull-out test showed very similar values in terms of Ultimate Strength Failure (USF), Stiffness at USF, and Stiffness:. The failure mode was bone plug fracture (12 for Transfix BTB and 13 for BioTransfix T3) and tendon failure (3 for Transfix BTB and 2 for BioTransfix T3). The post-test CT scan showed any failure of the fixation devices and the correct position inside the femoral half-tunnel. The mean bone density of porcine femora was comparable to young human femora (1.12±0.31 BMD). Both systems showed a similar behaviour in terms of USF, Stiffness, Cyclic load, method of failure and other biomechanical parameters. The reproducibility of surgical technique, the
Introduction. Bisphosphonates (BP) are the first-line therapy for preventing osteoporotic fragility fractures. However, concern regarding their efficacy is growing because bisphosphonate use is associated with over-suppression of remodeling. Animal studies have reported that BP therapy is associated with accumulation of micro-cracks (Fig. 1) and a reduction in bone mechanical properties, but the effect on humans has not been investigated. Therefore, our aim was to quantify the
Animal studies have shown that implanted anterior cruciate ligament (ACL) grafts initially undergo a process of revascularisation prior to remodelling, ultimately increasing
This study was performed to compare the mechanism of bone-implant integration and mechanical stability among three popularly used cementless implant surfaces. Plasma sprayed porous surface (TiPL), grit-blasted rough surface (TiGB), and hydroxyapatite coated implant surface (HA) were tested in a sheep model at 4 and 12 weeks. The integration patterns were investigated using histology, histomorphometry, and
The purpose of this study was to explore a simple and effective method of preparing human acellular amniotic membrane (HAAM) scaffolds, and explore the effect of HAAM scaffolds with juvenile cartilage fragments (JCFs) on osteochondral defects. HAAM scaffolds were constructed via trypsinization from fresh human amniotic membrane (HAM). The characteristics of the HAAM scaffolds were evaluated by haematoxylin and eosin (H&E) staining, picrosirius red staining, type II collagen immunostaining, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Human amniotic mesenchymal stem cells (hAMSCs) were isolated, and stemness was verified by multilineage differentiation. Then, third-generation (P3) hAMSCs were seeded on the HAAM scaffolds, and phalloidin staining and SEM were used to detect the growth of hAMSCs on the HAAM scaffolds. Osteochondral defects (diameter: 3.5 mm; depth: 3 mm) were created in the right patellar grooves of 20 New Zealand White rabbits. The rabbits were randomly divided into four groups: the control group (n = 5), the HAAM scaffolds group (n = 5), the JCFs group (n = 5), and the HAAM + JCFs group (n = 5). Macroscopic and histological assessments of the regenerated tissue were evaluated to validate the treatment results at 12 weeks.Aims
Methods
Introduction. Ultra high molecular weight polyethylene (UHMWPE) has been used successfully as a bearing material in hip, knee, and shoulder joint replacements. However, there are problems to cause a failure in UHMWPE component, which are wear behavior and creep deformation. Continuous bearing motion and dynamic load have occurred to UHMWPE wear debris caused osteolysis in periprosthetic tissue and to plastic deformation of joint component, and subsequent aseptic loosening of components. Therefore, many studies have being carried out in order to reduce wear debris and to improve
Only a little over a decade ago the vast majority of primary total hip replacements performed in North America, and indeed globally, employed a conventional polyethylene insert, either in a modular version or in a cemented application. Beginning in the early 2000's there was an explosion in technology and options available for the bearing choice in total hip arthroplasty. Highly crosslinked polyethylene was introduced in 1998, and within a few short years the vast majority of polyethylene inserts performed in North America were manufactured from this material. Globally there was a mixed picture with variable market penetration. Surgeons had seen historically poor results with attempts at “improving” polyethylene in the past and many were hesitant to use this new technology. Many randomised clinical trials have been performed and all have shown to a greater or lesser degree, that indeed the highly crosslinked polyethylene insert has undergone less linear and volumetric wear than its more conventional counterpart. This replicates well the hip simulator data. The challenge, however, is as we approached mid-term results, orthopaedic manufacturers began altering the polyethylene to improve wear and improve