Gap Healing Research Articles

SEFT as an Effort to Overcome the Manifestations of Burnout Syndrome

Burnout syndrome describes a response to chronic work-related stress. One of the techniques to overcome this is the Spiritual Emotional Freedom Technique (SEFT), which combines spiritual power and energy psychology. This study used a literature review with the PICOS framework. Article search using electronic databases: Google Scholar, Research Gate, PubMed, and Science Direct with the keywords "SEFT" OR "EFT" and "Burnout syndrome". The inclusion criteria in this literature review are articles published from 2016 to 2023, available in full-text form. Exclusion criteria: articles are only in the form of journal reviews, and papers are published in proceedings. Number of articles reviewed: 10. SEFT combines psychological energy and spiritual therapy by using the tapping method at several meridian points in the body. Improvement of physical and psychological complaints after the administration of SEFT psychotherapy is a form of mind-body gap healing. SEFT treats disruptions of the body's energy system to eliminate negative emotions

Development and evaluation of an injectable ChitHCl-MgSO4-DDA hydrogel for bone regeneration: In vitro and in vivo studies on cell migration and osteogenesis enhancement

Nonunion and delayed union of the bone are situations in orthopedic surgery that can occur even if the bone alignment is correct and there is sufficient mechanical stability. Surgeons usually apply artificial bone grafts in bone fracture gaps or in bone defect sites for osteogenesis to improve bone healing; however, these bone graft materials have no osteoinductive or osteogenic properties, and fit the morphology of the fracture gap with difficulty. In this study, we developed an injectable chitosan-based hydrogel with MgSO4 and dextran oxidative, with the purpose to improve bone healing through introducing an engineered chitosan-based hydrogel. The developed hydrogel can gelate and fit with any morphology or shape, has good biocompatibility, can enhance the cell-migration capacity, and can improve extracellular calcium deposition. Moreover, the amount of new bone formed by injecting the hydrogel in the bone tunnel was assessed by an in vivo test. We believe this injectable chitosan-based hydrogel has great potential for application in the orthopedic field to improve fracture gap healing.

Gap Volume Based on Computed Tomography Measurement Is a Strong Risk Factor for Delayed Gap Healing After Open-Wedge High Tibial Osteotomy

To identify factors that affect delayed gap healing after open-wedge high tibial osteotomy (OWHTO) and to determine whether large gap volume is a predictor of delayed gap healing. This retrospective study analyzed biplane OWHTO performed between 2019 and 2023 for knee osteoarthritis or osteonecrosis. The minimum follow-up period was 1 year. Delayed gap healing was defined when the medial half of the osteotomy gap area had not reached the consolidation phase by 6 months after surgery based on anteroposterior knee radiographs. Gap volume was calculated from computed tomography images. Logistic regression was performed using body height, smoking, correction angle, hinge fracture, flange thickness, and gap volume. A gap volume cutoff value for delayed gap healing was determined with receiver operating characteristic curve analysis. Gap volume was predicted with multiple linear regression. There were 80 knees in 71 patients (36 men and 44 women). The mean gap volume was 7.6 cm3. Gap healing rates at 3, 6, 9, and 12 months after surgery were 26%, 65%, 89%, and 100%, respectively. There were 25 knees with delayed gap healing. Male sex was not a significant risk factor when adjusted for body height. Multivariate logistic regression revealed that only larger gap volume was a significant risk factor (odds ratio, 1.45; P= .006). The gap volume cutoff value was 7.6 cm3, with an area under the curve of 0.74. Tall body height and a large correction angle (both P < .001) were associated with a significantly larger gap volume (R2= 0.73). Large gap volume is the most important risk factor for delayed gap healing after OWHTO. Gap volume can be predicted based on body height and correction angle. When OWHTO with substantial correction is planned for tall men, surgeons should be aware of possibly delayed gap healing. Level IV, retrospective case-control study.

A new technique of autologous bone grafting for open-wedge high tibial osteotomy.

This study aimed to demonstrate the application of orthotopic bone flap transplantation with a fibula transplantation (OBFT-FT) in open-wedge high tibial osteotomy (OW-HTO) and to assess the effect of OBFT-FT on gap healing. From January to July 2020, 18 patients who underwent OW-HTO with OBFT-FT were reviewed for this study. Demographics, postoperative complications, and radiological and clinical outcomes of patients were collected. Finally, the clinical outcomes of patients were analyzed. A total of 14 patients were included in this study. The average age and body mass index were 59.6 ± 9.2 years and 28.1 ± 4.5 kg/m2, respectively. The average correction angle and gap width were 9.5 ± 1.8° and 10.2 ± 2.7 mm, respectively. The rates of radiological gap healing at sixth week, third month, and sixth month were 42.9%, 85.7%, and 100%, respectively. The mean Lysholm score, International Knee Documentation Committee score, and visual analog scale scores at sixth-month follow-up were significantly better than the preoperative scores (p < 0.001, p < 0.001, p = 0.001, respectively). And, no delayed union or non-union, collapse, loss of correction, or surgical site infection were found. As a new technique for autologous bone graft, the OBFT-FT could be successfully applied in the treatment of gap healing after OW-HTO, and excellent radiological and clinical outcomes could be seen on patients' short-term follow-up.

Preparation and Characterization of Decellularized Caprine Periosteum Scaffolds for Fracture Gap Healing

Certain chemical and enzymes like sodium deoxycholate, sodium dodecyl sulphate and Triton X-100 have been used as biological detergents but are responsible for residual cytotoxicity in the decellularized extracellular matrix. The periosteum plays a key role in bone regeneration. We aimed to prepare decellularized caprine periosteum scaffold by exploring the decellularization property of Sapindus mukorossi fruit pericarp extract (SPE). We developed decellularization protocols to completely remove the periosteum cellular components and for good maintenance of the hierarchical multilayer structures and components of the extracellular matrix (ECM) with no cytotoxicity. Histological analysis of hematoxylin and eosin and Masson’s trichrome stained tissue samples decellularized by 5% SPE extract confirmed decellularization with preservation of extracellular matrix microarchitecture. DAPI stained decellularized tissues revealed complete removal of nuclear components, verified by DNA content measurement. It was concluded that 5% SPE is ideal for preparation of decellularized caprine periosteum scaffold and these scaffolds can be used for bone regeneration.

Phase field crystal simulation of gap healing at nanoscale

The phase field crystal method is used to simulate the healing process of the central gap of three-dimensional bcc crystal material under compressive strain at the atomic level. It is found that during the healing process of the central gap, the gap protrudes at both ends of it, leading to dislocation nucleation and vacancy formation. Through the mechanism of dislocation nucleation and dislocation emission, the thickness of gap is reduced layer by layer, and finally the connection and closure of the lattice atoms on up and down surface of the gap are achieved, and the surface healing of the central gap is realized. According to the sharpening and passivation mechanism of the lattice atomic planes at both ends of the gap, the elliptic shape gap is approximated to calculate and analyze the influence of the change of stress intensity factor during the gap healing, and the critical condition of the gap dislocation emission is determined.

The results of allogenic cancellous bone graft in medial opening wedge high tibial osteotomy.

There is no clear consensus regarding the optimal filling agent in the medial opening wedge high tibial osteotomy (MOWHTO). In this study, we evaluated the clinical and radiologic outcomes of MOWHTO with an allogeneic cancellous bone graft and TomoFix plate. Medical profiles of 122 patients who underwent MOWHTO with cancellous bone graft from iliac crest were retrospectively reviewed. One hundred and two patients (120 knees) who met the study criteria were included in the analysis. The osteotomy site was fixed with a TomoFix plate. The mean age of the patients was 40.85 ± 22.15years. The mean follow-up of the patients was 33.2 ± 29months. The primary outcome measures were the union of osteotomy site and loss of correction that were investigated on postoperative radiographs. Secondary outcome measures were postoperative complications that were extracted from the patients' medical records. Union of the osteotomy site was observed in all patients within three months after the operation. Loss of correction at the osteotomy site occurred in two knees (1.7%), both of which underwent revision surgery. Three patients had non-infected prolonged wound drainage and underwent reoperation for allograft removal. Nine other complications were also recorded that did not require intervention, including superficial infection (n = 2), compartment syndrome (n = 1), deep vein thrombosis (n = 1), loss of knee flexion (n = 2), and transient pain at the site of the osteotomy (n = 3). Allogenic cancellous bone graft provides efficient gap healing in MOWHTO and can be used as an effective alternative to the autogenous bone graft.

Seamless and early gap healing of osteochondral defects by autologous mosaicplasty combined with bioactive supramolecular nanofiber-enabled gelatin methacryloyl (BSN-GelMA) hydrogel.

Autologous mosaicplasty is a common approach used to treat osteochondral defects in clinical practice. Gap integration between host and transplanted plugs requires bone tissue reservation and hyaline cartilage regeneration without uneven surface, graft necrosis and sclerosis. However, poor gap integration is a serious concern, which eventually leads to deterioration of joint function. To deal with such complications, this study has developed a strategy to effectively enhance integration of the gap region following mosaicplasty by applying injectable bioactive supramolecular nanofiber-enabled gelatin methacryloyl (GelMA) hydrogel (BSN-GelMA). A rabbit osteochondral defect model demonstrated that BSN-GelMA achieved seamless osteochondral healing in the gap region between plugs of osteochondral defects following mosaicplasty, as early as six weeks. Moreover, the International Cartilage Repair Society score, histology score, glycosaminoglycan content, subchondral bone volume, and collagen II expression were observed to be the highest in the gap region of BSN-GelMA treated group. This improved outcome was due to bio-interactive materials, which acted as tissue fillers to bridge the gap, prevent cartilage degeneration, and promote graft survival and migration of bone marrow mesenchymal stem cells by releasing bioactive supramolecular nanofibers from the GelMA hydrogel. This study provides a powerful and applicable approach to improve gap integration after autologous mosaicplasty. It is also a promising off-the-shelf bioactive material for cell-free in situ tissue regeneration.

Parathyroid hormone enhances gap healing and osseointegration in orthopedic porous coated titanium implants: a correlative micro-computed tomographic, histomorphometric and biomechanical analysis

BackgroundParathyroid hormone, with its anabolic effect on bone formation, has shown excellent outcomes of curing postmenopausal osteoporosis as well as enhancing osseointegration around orthopaedic and stomatologic implants.The purpose of the present study is to test if low-dose intermittent PTH (1–34) treatment could achieve a satisfactory osseointegration in 2-mm peri-implant gaps, as to provide a new idea for improving the stability of such prosthesis, which will be of great clinical value.MethodsA custom-made titanium implant was implanted on the calvarium of New Zealand White rabbits. 48 male rabbits were randomly divided into control and PTH group. PTH group received subcutaneous injection of PTH (20 μg/day, 5 days/week). Animals were sacrificed at 4 and 8 weeks after surgery. Quantitative micro-computed tomography, histology and biomechanical pull-out testing were performed to evaluate the gap healing at implantation site.ResultsAnalysis of micro-computed tomography demonstrated that PTH group achieved more new bone formation in 2-mm gaps and on bone-implant interface. Quantitatively, significant differences were observed between two groups in regard to BIC and BV/TV at each time-point. Histological staining revealed that PTH group had a superiority in trabecular number, thickness, separation and better osseointegration compared to control group. As for biomechanical pull-out testing, PTH group also showed significant improvement of ultimate force than control group.ConclusionsLow-dose intermittent administration of PTH for 4 and 8 weeks enhances early osseointegration and fixation of orthopedic implants surrounded by a 2-mm gap in terms of increased bone regeneration and mechanical stability. These findings suggest PTH a potential for reducing the postoperative complications of implants by improving bone healing at peri-implant gaps.

Robust and Fast CAD Model Tessellation for Inspection

The digital manufacturing deviation inspection can be used to assess the dimension, form, and position errors, which is more efficient, more consistent, and more robust than manual inspection. CAD models are used as the nominal data and compared with the scanned data of parts to obtain manufacturing errors. CAD model tessellation is a pivotal step in deviation inspection, which directly determines the reliability of analytical results. It requires that the generated triangle mesh has dense vertices, high approximation accuracy, and consistent orientation. A single surface patch tessellation method is proposed, and the adaptive quadtree is first constructed to divide the domain into small spatial grids in the parameter space of the patch; then, a clip-based method is presented to triangulate boundary grids, and inner grids could be triangulated by the constrained Delaunay triangulation method. Furthermore, the mesh patches should be spliced and reoriented consistently, which is very important for deviation analysis. To solve this problem, a robust gap healing method based on merging boundary points of patches is developed, so that all boundary vertices of adjacent patches could completely coincide along the common edges, and all mesh patches would be stitched into a complete mesh without gaps. Finally, the face normal of mesh is adjusted to obtain a consistent orientation. Experiments on industrial CAD models demonstrate that the proposed method could realize faster and more robust mesh generation than the state-of-the-art approaches, including three commercial and two open-source software.

A stochastic micro to macro mechanical model for the evolution of bone-implant interface stiffness

Upon placement of an implant into living bone, an interface is formed through which various biochemical, biological, physical, and mechanical interactions take place. This interface evolves over time as the mechanical properties of peri-implant bone increase. Owing to the multifactorial nature of interfacial processes, it is challenging to devise a comprehensive model for predicting the mechanical behavior of the bone-implant interface. We propose a simple spatio-temporally evolving mechanical model – from an elementary unit cell comprising randomly oriented mineralized collagen fibrils having randomly assigned stiffness all the way up to a macroscopic bone-implant interface in a gap healing scenario. Each unit cell has an assigned Young's modulus value between 1.62 GPa and 25.73 GPa corresponding to minimum (i.e., 0) and maximum (i.e., 0.4) limits of mineral volume fraction, respectively, in the overlap region of the mineralized collagen fibril. Gap closure and subsequent stiffening are modeled to reflect the two main directions of peri-implant bone formation, i.e., contact osteogenesis and distance osteogenesis. The linear elastic stochastic finite element model reveals highly nonlinear temporal evolution of bone-implant interface stiffness, strongly dictated by the specific kinetics of contact osteogenesis and distance osteogenesis. The bone-implant interface possesses a small stiffness until gap closure, which subsequently evolves into a much higher stiffness, and this transition is reminiscent of a percolation transition whose threshold corresponds to gap closure. The model presented here, albeit preliminary, can be incorporated into future calculations of the bone-implant system where the interface is well-defined mechanically. Statement of significanceA simple, physically informed model for the mechanical characteristics of the bone-implant interface is still missing. Here, we start by extending the reported mechanical characteristics of a one cubic micrometre unit cell to a 250 µm long interface made of 1 µm thick layers. The stiffness of each cell (based on mineral content) is assigned randomly to mimic bone micro-heterogeneity. The numerical study of this interface representative structure allows for the simultaneous determination of the spatio-temporal evolution of the mechanical response at local (discrete element) and global (overall model) scales. The proposed model is the first of this kind that can easily be incorporated into realistic future models of bone-implant interaction with emphasis on implant stability and different loading conditions.

Association of Gap Healing With Angle of Correction After Opening-Wedge High Tibial Osteotomy Without Bone Grafting

Background:Studies have reported that opening wedge high tibial osteotomy (OWHTO) without bone grafting has outcomes that are similar to or even better than those of OWHTO with bone grafting, especially after use of a locking plate. However, a consensus on managing the gap after OWHTO has not been established.Purpose:To determine the degree of gap healing achieved without bone grafting, the factors associated with gap healing, and whether additional gap healing would be obtained after plate removal.Study Design:Cohort study; Level of evidence, 3.Methods:This retrospective study included 73 patients who underwent OWHTO without bone grafting between 2015 and 2018. Patients in the study were divided into 2 groups based on the correction angle: small correction group (<10°; SC group) and large correction group (≥10°; LC group). The locking plate used in OWHTO was removed at a mean of 13.5 months after surgery in 65 patients. Radiographic indexes were measured: gap filling height, gap vacancy ratio (GVR), and osteotomy filling index. The acceptable gap healing was defined as an osteotomy filling index ≥3. The factors related to gap healing around the osteotomy site were selected after multicollinearity analysis.Results:Although both groups achieved acceptable gap healing regardless of the correction angle, the SC group showed higher and earlier gap healing than did the LC group (gap healing rate 81.4% in the SC group vs 41.7% in the LC group at 3 months postoperatively). The GVR was 8.6% in the SC group and 15.3% in the LC group at 12 months after surgery (P = .005). Both the amount of time that elapsed after surgery and the correction angle were associated with gap healing (P < .05). Additional gap healing was observed after plate removal, as the GVR decreased 2.7% more in the patients with plate removal than in patients who did not have plate removal (P = .012).Conclusion:All patients achieved acceptable gap healing without bone graft. The degree of gap healing was higher in the SC group and increased over time. Gap healing was promoted after plate removal. Considering the results of this study, a bone graft is not necessary in routine OWHTO in terms of gap healing.

Antimicrobial silver-coating for locking plates shows uneventful osteotomy healing and good biocompatibility results of an experimental study in rabbits

Infections after internal fixation of fractures remain a challenge. Silver is known for its antimicrobial activity, including activity against multi-resistant strains. The aim of the current study was to analyze the biocompatibility and potential influence on the osteotomy healing process of a silver-coating technology for locking plates compared to silver-free locking plates in an established rabbit model.The implants used in this study were 7-hole titanium locking plates, and plasma electrolytic oxidation (PEO) silver-coated equivalents. A total of 24 rabbits were used in this study (12 coated, 12 non-coated). An osteotomy of the midshaft of the humerus was created and the humerus stabilized with the 7-hole locking plates with a total of 6 screws. Radiographs were taken on day 0, week 2, 4, 6, 8, and 10 for continuous radiographical evaluation. All animals were euthanized after 10 weeks and further assessment was performed using X-rays, micro-CT, non-destructive four-point bending biomechanical testing and semi-quantitative histopathological evaluation. Furthermore, silver concentration was measured in the blood, kidney, liver, spleen, brain, feces and soft tissue around the plate.Radiographs showed normal undisturbed and completed healing of the osteotomy in all animals without any differences between the two groups over the entire observation period. Micro-CT analysis revealed overall tissue volume as well as tissue density to be comparable between the two groups. Mechanical testing showed comparable stiffness with an average stiffness relative to contralateral bones of 75.7 ± 16.1% in the silver-free control group compared to 69.7 ± 18.5% (p-value: 0.46). Semi-quantitative histopathological evaluation showed no remarkable difference in the analysis of the osteotomy gap healing or in the surrounding soft tissue area. There were detectable silver concentrations in the soft tissue around the plate after 10 weeks. Silver in the blood was only found in 3 animals within the first two weeks and all animals were free of silver afterwards. There were no detectable silver concentrations in the brain, liver, spleen, axillary lymph nodes and kidney.This study shows undisturbed osteotomy healing of the presented antimicrobial silver surface coating and a good biocompatibility in this rabbit model.

Plate-related results of opening wedge high tibial osteotomy with a carbon fiber reinforced poly-ether-ether-ketone (CF-PEEK) plate fixation: a retrospective case series of 346 knees

BackgroundWhile open wedge high tibial osteotomy (owHTO) is an established standard procedure to treat medial osteoarthritis of the knee in combination with varus deformity, it bears the risk of postoperative hardware failures and lateral cortical hinge fractures. This in turn can lead to an accelerated osteoarthritis, non-union, or a loss of correction accuracy. The purpose of the study was to evaluate the radiologic outcomes of owHTO with a carbon fiber reinforced poly-ether-ether-ketone (CF-PEEK) plate fixation in patients with medial osteoarthritis and varus deformity.MethodsThree hundred twenty-four consecutive patients (346 knees) who were treated with owHTO using the PEEKPower HTO plate were included in this retrospective study; 89.9% of the patients were overweight or obese. Patients were followed by conventional radiographs over a 12-month period. Typical plate-related results such as the time and quality of gap healing as well as the correction accuracy were analyzed. Furthermore, the number of lateral cortex fractures was determined.ResultsBony consolidation was observed after a mean gap healing time of 4.0 ± 1.7 months independent on the patients’ weight (p = 0.2302). With increasing gap sizes, bony healing was significantly prolonged (p < 0.001). Additionally, patients with greater gap sizes had a significantly increased risk for a lateral cortex fracture (p = 0.0041). However, none of the patients had a non-union 1 year postoperative. A hinge fracture occurred in 30% of patients. Hinge fractures with Takeuchi grades I and II increased the gap healing time compared to no fracture (p = 0.0069 and p = 0.0002, respectively), but only 1.2% of patients with hinge fracture had a clinical relevant loss of correction ≥ 3 mm. No implant failures were found.ConclusionsOpen wedge HTO using the PEEKPower HTO plate for patients with medial osteoarthritis of the knee in combination with tibial varus deformity leads to excellent bony consolidation also in cases with a hinge fracture, a gap size > 12 mm as well as for severely obese patients.

Effects of endogenous inflammation signals elicited by nerve growth factor, interferon-\u03b3, and interleukin-4 on peripheral nerve regeneration

BackgroundLarge gap healing is a difficult issue in the recovery of peripheral nerve injury. The present study provides in vivo trials of silicone rubber chambers filled with collagen containing IFN-γ or IL-4 to bridge a 15 mm sciatic nerve defect in rats. Fillings of NGF and normal saline were used as the positive and negative controls. Neuronal electrophysiology, neuronal connectivity, macrophage infiltration, location and expression levels of calcitonin gene-related peptide and histology of the regenerated nerves were evaluated.ResultsAt the end of 6 weeks, animals from the groups of NGF and IL-4 had dramatic higher rates of successful regeneration (100 and 80%) across the wide gap as compared to the groups of IFN-γ and saline controls (30 and 40%). In addition, the NGF group had significantly higher NCV and shorter latency compared to IFN-γ group (P < 0.05). The IL-4 group recruited significantly more macrophages in the nerves as compared to the saline controls and the NGF-treated animals (P < 0.05).ConclusionsThe current study demonstrated that NGF and IL-4 show potential growth-promoting capability for peripheral nerve regeneration. These fillings in the bridging conduits may modulate local inflammatory conditions affecting recovery of the nerves.

Does PRP Improve the Tendon Gap Healing?

Background: The tendon repairs slowly. Platelets’ alpha granules contain polypeptide growth factors that stimulate proliferation of normal connective tissue cells. The acute phase of inflammation is necessary for healing progress and fibroplasia. Platelet growth factors initiate and accelerate the inflammatory response by the host. Objectives: This study aimed to investigate if platelet-rich plasma (PRP) helps tendon gap healing. Methods: Aseptic surgery was performed on 24 mature guinea pigs in four groups to excise a 7-mm piece of the deep digital flexor (DDF) tendon of the right hind leg. In groups 1 and 2, the two ends of the severed tendon were sutured in the fascia conduit; group 2 received PRP injection into the conduit. In groups 3 and 4, the two ends of the severed tendon were sutured in a silicone tube conduit, and group 4 received PRP injection. After 42 days, the animals were euthanized and tendon samples were collected for further study. Results: The histopathological and stereological data showed that inflammation was far less in PRP-treated groups as they showed more fibroblastic proliferation. The synergistic effects of silicone tube and PRP injection showed the least inflammatory response. The diameter of collagen bundles and their volume were higher in the groups which received PRP in the silicone conduit. Conclusions: The present study found that PRP improved healing of tendon injury and silicone conduit served as good surgical technique with synergistic effect beside PRP.

Grafting with double-layered polypropylene mesh for gap healing of mid-metacarpal superficial digital flexor tendon in Equus asinus: clinical and pathological evaluations

Tendon injury is one of the most common causes of wastage in equine. The superficial digital flexor tendon (SDFT) gets affected the most, especially in the mid-metacarpal region. Several studies have focused on the grafting of severed SDFT, but no ideal grafting material has been approved for clinical application. The present study aimed to evaluate the grafting of the mid-metacarpal SDFT in donkeys with a double-layered polypropylene mesh clinically, ultrasonically, macro/microscopically. Clinically healthy adult donkeys (n = 24) were divided randomly and equally into two groups: control (C) and study (S) groups. Tenotomy was performed on all animals by excising a full-thickness segment from the mid-metacarpal SDFT. In the C group, a suture tenorrhaphy was performed. While in the S group, SDFT was grafted with the double-layered polypropylene mesh. The S group showed faster clinical improvements, and earlier appearance of normal newly formed tendinous tissue ultrasonically compared with the C group. Macroscopically, the grafted tendons showed a rapid restoration of normal color and consistency. Moreover, they had minimal peri-tendinous adhesions compared with the non-grafted tendons. Microscopically, the grafted tendons showed earlier vascularization and more mature collagen fibers compared with the non-grafted tendons. In the present study, we have succeeded to graft the gap of the mid-metacarpal SDFT of a donkey using the double-layered polypropylene mesh. This method is an economical way to accelerate the healing process of the SDFT and enhance the clinical recovery in donkeys.

The effect of bone healing condition on the stress of screw fixation in orthotropic femur bone for fracture stabilization

Abstract The stability on the fracture site is an important precondition for successful healing. Osteosynthesis is an alternative treatment for the stabilization of femur bone. Besides, the fractured bone experiences direct (primary) or indirect (secondary) healing which can be divided into two healing conditions (i.e. contact healing and gap healing). The healing of unstable fracture is essentially characterized by callus formation prior to healing. Understanding the stability on the fracture site is necessary to determine the parameters which will influence the implant stability. Nonetheless, there is a lack of study with regards to the influence of the osteosynthesis on the fixation strength and micro motion at of the fracture gap. Hence, for all intents and purposes, this study is aimed to investigate the influence of healing condition on the critical stress of cortex screws. Apart from that, this study is also expected to identify the yield region on cortex screws. Uninterruptedly, the results have revealed that the stress of plate fixation is significantly affected by the healing conditions. In particular, bone healing leads to a greater stress concentration on the screws, whilst the distribution is more uniform in contact healing condition. Furthermore, the results show that the different material properties at different modulus of bone healing imparted effect to the stress concentration on the screws.

The effect of plate design, bridging span, and fracture healing on the performance of high tibial osteotomy plates: An experimental and finite element study.

ObjectivesOpening wedge high tibial osteotomy (HTO) is an established surgical procedure for the treatment of early-stage knee arthritis. Other than infection, the majority of complications are related to mechanical factors – in particular, stimulation of healing at the osteotomy site. This study used finite element (FE) analysis to investigate the effect of plate design and bridging span on interfragmentary movement (IFM) and the influence of fracture healing on plate stress and potential failure.Materials and MethodsA 10° opening wedge HTO was created in a composite tibia. Imaging and strain gauge data were used to create and validate FE models. Models of an intact tibia and a tibia implanted with a custom HTO plate using two different bridging spans were validated against experimental data. Physiological muscle forces and different stages of osteotomy gap healing simulating up to six weeks postoperatively were then incorporated. Predictions of plate stress and IFM for the custom plate were compared against predictions for an industry standard plate (TomoFix).ResultsFor both plate types, long spans increased IFM but did not substantially alter peak plate stress. The custom plate increased axial and shear IFM values by up to 24% and 47%, respectively, compared with the TomoFix. In all cases, a callus stiffness of 528 MPa was required to reduce plate stress below the fatigue strength of titanium alloy.ConclusionWe demonstrate that larger bridging spans in opening wedge HTO increase IFM without substantially increasing plate stress. The results indicate, however, that callus healing is required to prevent fatigue failure.Cite this article: A. R. MacLeod, G. Serrancoli, B. J. Fregly, A. D. Toms, H. S. Gill. The effect of plate design, bridging span, and fracture healing on the performance of high tibial osteotomy plates: An experimental and finite element study. Bone Joint Res 2018;7:639–649. DOI: 10.1302/2046-3758.712.BJR-2018-0035.R1.

Bone autografting in medial open wedge high tibial osteotomy results in improved osseous gap healing on computed tomography, but no functional advantage: a prospective, randomised, controlled trial.

Medial open wedge high tibial osteotomy (owHTO) is a valuable surgical technique used to manage medial degeneration in varus knees. Iliac crest autograft is considered the gold standard gap-filler. It was hypothesised that iliac crest autograft promotes gap healing and improves functional outcome in owHTO. Between 2005 and 2009, patients scheduled to undergo owHTO stabilised by a medial locking compression plate were randomised to undergo owHTO either with iliac crest autograft (group A) or without bone void filler (group B). Pre- and postoperative leg axes were recorded. At 3 and 12months postoperatively, the healing of the osteotomy gap was measured as a percentage on CT images, and functional scores were recorded. There were 15 patients in group A, and 25 in group B. The groups were similar in age, sex ratio, knee varus deformity, body mass index, and smoking status. Group A and B had similar preoperative varus (6.9° vs. 7.6°) and postoperative valgus (2.2° vs. 3.0°). Compared with the control group, group A had a significantly greater degree of osseous gap healing after 3months (40.1% vs. 10.8%, p = 0.045) and 12months (91.5% vs. 59.1%, p ≤ 0.001). Multiple linear regression analysis found that bone grafting was an independent promoting factor for gap healing, while increased preoperative varus was an independent retardant factor at 3months (p = 0.004 and p = 0.002, respectively) and 12months (p ≤ 0.001 and p = 0.003, respectively). Younger age was a promoting factor for gap healing on CT at 3months (p ≤ 0.001), but not at 12months. No correlations were found between bone healing and functional outcome, body mass index, or smoking status. Iliac crest autograft significantly increases healing of the osteotomy gap after owHTO. Increased preoperative varus and older patient age are independent factors that delay early healing of the osteotomy. However, no functional advantage was found at 3 or 12months postoperatively. Therefore, routine use of iliac crest autograft cannot be recommended. II.