Introduction and Objective. The patients with a total hip arthroplasty is growing in world manly in Europe and USA, and this solution present a high success at 10years in several orthopaedic registers. The application of total press-fit hip fixation presents the most used solution, but presents some failures associated to the acetabular component fixation, associated to the load transfer and bone loss at long term. The aim of this work is to investigate the influence of different acetabular bone loss in the strain distribution in iliac bone. To evaluate implant fixation, an experimental study was performed using acetabular press-fit component simulating different acetabular bone loss and measuring the strain distribution. Materials and Methods. The experimental samples developed was based in an iliac bone model of Sawbones supplier and a acetabular component Titanium (Stryker) in a condition press-fit fixation and was implanted according surgical procedure with 45º inclination angle and 20º in the anteversion angle. Were developed five models with same initial bone, one with intact condition simulating the cartilage between bones and four with different bone loss around the acetabular component. These four models representing the evolution of bone support of acetabular components presented in the literature. The evolution of bone loss was imposed with a CAD CAM process in same iliac bone model. The models were instrumented with 5 rosettes in critical region at the cortical bone to measure the strain evolution along the process. Results. The results of strain gauges present the influence of acetabular component implantation, reducing the bone strains and presented the effect of the strain shielding. The acetabular component works as a shield in the load transfer. The critical region is the posterior region with highest principal strains and the strain effect was observed with different bone loss around acetabular component. The maximum value of principal strain was observed in the intact condition in the anterior region, with 950μ∊. In the posterior superior region, the effect of bone loss is more important presenting a reduction of 500% in the strains. The effect of bone loss is presented in the strains induced with acetabular implantation, in the first step of implantation the maximum strain was 950μ∊ and in the last model the value was 50μ∊, indicating lower press-fit fixation. Conclusions. The models developed allows study the effect of bone loss and acetabular implant fixation in the load transfer at the hip articulation. The results presented a critical region as the anterior-superior and the effect of strain shielding was observed in comparison with intact articulation. The results of press-fit fixation present a reduction of implant stability along bone loss. The process of bone fixation developed present some limitation associated to the bone adhesion in the interface, not considered. Acknowledgement. This work was supported by POCI-01-0145-FEDER-032486,– FCT, by the FEDER, with COMPETE2020 - (POCI), FCT/M

Background. The discussion over the duration, type of therapy and regimen to be used in osteoarticular tuberculosis is losing importance in all orthopaedic gathering. Still little consensus is there over the universality of a treatment regime for osteoarticular tuberculosis. Material and Method. 340 new cases of osteoarticular tuberculosis were included in the study that were medically treated in the department of orthopaedics in a tertiary care center between 2001 and 2011. Out of which 202 cases were of spinal tuberculosis and 138 cases of extraspinal tuberculosis. 88 cases of spinal tuberculosis were treated by conventional method and 114 cases by short course chemotherapy. 60 cases of extraarticular tuberculosis were treated by conventional chemotherapy and 78 cases by short course and intermittent therapy. Results. All cases were evaluated on clinical, radiological and haematological basis. Cases who received conventional therapy received 18–24 months of treatment irrespective to the clinical, radiological and haematological parameters. Whereas those who received short course (2HRZE+4 HR) and intermittent therapy (DOTS) were evaluated for clinical improvement. Maximum follow up was of 12.8 years (conventional) minimum follow of 8 years (intermittent). The trend of fall in ESR, clinical and radiological parameters showed improvement beyond 2 years of initiation of treatment in cases that had stopped treatment at 6 months. But the improvement was slow after six months even in cases who received 24 months of chemotherapy. There were no relapses in all the three groups. Conclusion. This study reinforces that chemotherapy tailored to the response of treatment (6-9months) is the rational therapy. This study gives an insight over the evolution of different regimes as well as gives an understanding of the clinical treatment. Level of Evidence. Level 1. No relevant financial disclosures or conflicts of interest from any of the authors

The study aimed to compare trochlear profiles in recent total knee arthroplasty (TKA) models and to determine whether they feature improvements compared to their predecessors. The hypothesis was that recent TKA models have more anatomic trochlear compartments and would display no signs of trochlear dysplasia.

The authors analyzed the geometry of the 6 following TKA models using engineering software: PFC and Attune (DePuy), NexGen and Persona (Zimmer), Noetos and KneeTec (Tornier). The mediolateral trochlear profiles were plotted at various flexion angles (0°, 15°, 30° and 45°) to deduce the sulcus angle.

Analysis of sulcus angles reveals general convergence of recent designs towards anatomic values. At 0° of flexion, sulcus angles of recent implant models were between 156.0–157.4°, while those of previous generation models between 154.5–165.5°. At 30° of flexion, sulcus angles of recent models also lie within 145.7–148.6°, but those of previous models are between 149.5–152.0°. All three manufacturers deepened their trochlear profile at 30° of flexion in recent models compared to earlier designs. Sulcus angles converge towards anatomic values but still exceed radiologic signs of dysplasia by 2–5°.

Recent TKA designs have more anatomic trochlear geometries than earlier TKA models by the same manufacturers, but trochlear compartments still exceed radiologic signs of trochlear dysplasia by 2° to 5°. The hypothesis that recent TKA models display no signs of trochlear dysplasia is therefore refuted. Surgeons should be aware of design limitations to optimize choice of implant and extensor mechanisms alignment. Level of evidence: IV geometric implant analysis.

Total ankle replacement (TAR) is contraindicated in patients with significant talar collapse due to AVN and in these patients total talus body prosthesis has been proposed to restore ankle joint. To date, five studies have reported implantation of a custom-made talar body in patients with severely damaged talus, showing the limit of short-term damage of tibial and calcaneal thalamic joint surfaces. Four of this kind of implants have been performed. The first two realized with “traditional” technology CAD-CAM has been performed in active patients affected by “missing talus” and now presents a survival follow-up of 15 and 17 years. For the third patient affected by massive talus AVN we designed a 3D printed porous titanium custom talar body prosthesis fixed on the calcaneum and coupled with a TAR, first acquiring high-resolution 3D CT images of the contralateral healthy talus that was “mirroring” obtaining the volume of fractured talus in order to provide the optimal fit. Then the 3D printed implant was manufactured. The fourth concern a TAR septic mobilization with high bone loss of the talus. The “two-stage” reconstruction conducted with the implant of total tibio-talo-calcaneal prosthesis “custom made” built with the same technology 3D, entirely in titanium and using the “trabecular metal” technology for the calcaneous interface. Weightbearing has progressively allowed after 6 weeks. No complications were observed. All the implants are still in place with an overall joint mobility ranging from 40° to 60°. This treatment requires high demanding technical skills and experience with TAR and foot and ankle trauma. The 15 years survival of 2 total talar prosthesis coupled to a TAR manufactured by a CAD-CAM procedure encourages consider this 3D printed custom implant as a new alternative solution for massive AVN and traumatic missing talus in active patients.

The CCI mobile bearing ankle implant used at our orthopedic department 2010–2013, was abandoned due to failures and findings of bone loss at revision. The aim of this study was to a) Determine our true revision rate, b) Investigate accuracy of measuring prevalence, size and location of periprosthetic bone cysts through X-ray and CT and c) Relate these findings to implant alignment and patient reported outcome measurements (PROMs).

51 primary surgeries were performed, prior to this study 8 had been revised. Out of 43 un-revised patients, 36 were enrolled and underwent evaluation with metal artefact reduction CT-scans and conventional X-ray. They filled out 3 PROMs; SEFAS, SF-12, EQ-5D. Cyst volume larger than 0.1 ml was measured using VITREA volume tools for CT-scans and calculation of spherical volume for X-rays; using AP- and lateral projections. Location of lesions was recorded, according to their position relative to the implant. Medial-/lateral- and anterior-/posterior tilt of the implant parts was measured using IMPAX built in measuring tools, applied to AP- and lateral X-ray projection. The relation between lesions location and alignment of components was analyzed by logistic regression. Bias and ICC estimation between CT and X-ray was analyzed by mixed effect model. Log transformation was used to fit the normal distribution assumption. PROMs association to osteolytic volume was analyzed by linear- and logistic regression. P-values of 0.05 were considered statistically significant.

Finding large osteolytic lesions caused 4 additional patients to undergo revision and 7 are being monitored due to high risk of failure. Of the original 51 implants 14 have been revised. 8 cases because of osteolytic lesions and aseptic loosening (true revisions w. exchange of components or bone transplants), 3 periprosthetic fractures (2 non-traumatic fractures) and 3 cases of exostosis. The 3- and 5 year revision rate was 14% and 16% for true revisions and 17% and 27% overall. Cystic lesions were found in 81% of participants. Total cyst-volume was on average 13% larger on X-ray, however this difference was not significant (p = 0.55), with intraclass correlation being 0.66. Total cystic volume was not significantly related to PROM-scores (P 0.16–0.5). Location of cysts showed association with alignment of components (P 0.02–0.08). Mean tibia component anterior tilt was 89 degrees (SD 4). Mean medial tilt was 91 degrees (SD 3) for the tibial and 90 degrees (SD 4) for the talar component.

The implant investigated performs below standard, compared to public registries^{1, 2}that report overall 5 year revision rates at 5 – 6.5%. We obtained larger measurements from X-rays than CT, unlike previous studies comparing these modalities. Cysts were common and large. Correlation between lesion location and alignment of implant, with valgus and anterior tilt of components causing more lesions in adjacent zones, may suggest a link between implant failure and alignment of components.

Patients who are Jehovah's witnesses do not accept blood transfusions. Thus, total hip arthroplasty can be challenging in this group of patients due to the potential for blood loss. Multiple strategies have been developed in order to prevent blood loss. A 76-year-old female, Jehovah's witness medicated with a platelet antiaggregant, presented to the emergency department after a fall from standing height. Clinically, she had pain mobilizing the right lower limb and radiological examination revealed an acetabular fracture with femoral head protrusion and ipsilateral isquiopubic fracture. Skeletal traction was applied to the femur during three weeks and no weight bearing was maintained during the following weeks. Posteriorly, there was an evolution to hip osteoarthritis with necrosis of the femoral head. The patient was submitted to surgery six months after the initial trauma, for a total hip arthroplasty. The surgery was performed with hypotensive anaesthesia, careful surgical technique and meticulous haemostasis and there was no need for blood transfusion. Posteriorly, there was a positive clinical evolution with progressive improvement on function and deambulation. Total hip arthroplasty may be safely carried out with good clinical outcomes in Jehovah's witnesses, without the need for blood transfusion, if proper perioperative precautions are taken, as has already been shown in previous studies

Bone infections due to fractures or implants are a big medical problem. In experimental medicine, many experimental models have been created on different animal species to simulate the disease condition and to do experience treatments. The aim of this paper was to present an antibacterial efficacy of using a bone allograft developed according to the Marburg system of bone bank on a model of chronic osteomyelitis induced in rabbits. In research was used 54 rabbits. Osteomyelitis was induced in rabbits by a human strain of St. aureus ATCC 43300, in the rabbit femur. There have been created 3 groups of animals. In 1. st. group used antibiotic impregnated biodegradable material “PerOssal”. In 2. nd. group used antibiotic impregnated whole bone allograft. In 3. rd. group used antibiotic impregnated perforated bone allograft. Evaluation of installation and evolution of the disease was done by microbiological. A separate study of microbiological data is presented here. This study showed, in the 1. st. and 3. rd. groups there is a persistent decrease in CFU by 14 knocks to 120.4 in the 1. st. group and to 3.5 in the 3. rd. group, and in the 2. nd. group, on the contrary, there is an increase in CFU to 237.33. This shows the lack of effectiveness of using a whole bone allograft. The results showed, after 7 days there was no statistically significant difference between the groups. After 14 days the perforated bone allograft impregnated with antibiotic was better than the biodegradable material “PerOssal”

Developments in the field of additive manufacturing have allowed significant improvements in the design and production of scaffolds with biologically relevant features to treat bone defects. Unfortunately, the workflow to generate personalized scaffolds is source of inaccuracies leading to a poor fit between the implant and patients' bone defects. In addition, scaffolds are often brittle and fragile, uneasing their handling by surgeons, with significant risks of fracture during their insertion in the defect. Consequently, we developed organo-mineral cementitious scaffolds displaying evolutive mechanical properties which are currently being evaluated to treat maxillofacial bone deformities in veterinary clinics. Treatment of dog patients was approved by ethic and welfare committees (CERVO-2022-14-V). To date, 8 puppies with cleft palate/lip deformities received the following treatment. Two weeks prior surgery, CT-scan of patient's skull was performed to allow for surgical planning and scaffold designing. Organo-mineral printable pastes were formulated by mixing an inorganic cement precursor (α-Ca3(PO4)2) to a self-reticulating hydrogel (silanized hyaluronic acid) supplemented with a viscosifier (hydroxymethylpropylcellulose). Scaffolds were produced by robocasting of these pastes. Surgical interventions included the reconstruction of soft tissues, and the insertion of the scaffold soaked with autologous bone marrow. Bone formation was monitored 3 and 6 months after reconstruction, and a biopsy at 6 months was performed for more detailed analyses. Scaffolds displayed great handling properties and were inserted within bone defects without significant issue with a relevant bone edges/scaffold contact. Osteointegration of the scaffolds was observed after 3 months, and regeneration of the defect at 6 months seemed quite promising. Preliminary results have demonstrated a potential of the set-up strategy to treat cleft lip/palate deformities in real, spontaneous clinical setting. Translation of these innovative scaffolds to orthopedics is planned for a near future

Pelvic tilt can vary over time due to aging and the possible appearance of sagittal spine disorders. Cup position in total hip arthroplasty (THA) can be influenced due to these changes. We assessed the evolution of pelvic tilt and cup position after THA and the possible appearance of complications for a minimum follow-up of ten years. 343 patients received a THA between 2006 and 2009. All were diagnosed with primary osteoarthritis and their mean age was 63.3 years (range, 56 to 80). 168 were women and 175 men. 250 had no significant lumbar pathology, 76 had significant lumbar pathology and 16 had lumbar fusion. Radiological analysis included sacro-femoral-pubic (SFP), acetabular abduction (AA) and anteversion cup (AV) angles. Measurements were done pre-operatively and at 6 weeks, and at five and ten years post-operatively. Three measurements were recorded and the mean obtained at all intervals. All radiographs were evaluated by the same author, who was not involved in the surgery. There were nine dislocations: six were solved with closed reduction, and three required cup revision. All the mean angles changed over time; the SFP angle from 59.2º to 60º (p=0.249), the AA angle from 44.5º to 46.8º (p=0.218), and the AV angle from 14.7º to 16.2º (p=0.002). The SFP angle was lower in older patients at all intervals (p<0.001). The SFP angle changed from 63.8 to 60.4º in women and from 59.4º to 59.3º in men, from 58.6º to 59.6º (p=0.012). The SFP angle changed from 62.7º to 60.9º in patients without lumbar pathology, from 58.6º to 57.4º in patients with lumbar pathology, and from 57.0º to 56.4º in patients with a lumbar fusion (p=0.919). The SFP cup angle was higher in patients without lumbar pathology than in the other groups (p<0.001), however, it changed more than in patients with lumbar pathology or fusion at ten years after THA (p=0.04). Posterior pelvic tilt changed with aging, influencing the cup position in patients after a THA. Changes due to lumbar pathology could influence the appearance of complications long-term

An increasingly used treatment for end-stage ankle osteoarthritis is total ankle replacement (TAR). However, implant loosening and subsidence are commonly reported complications, leading to relatively high TAR failure rates. Malalignment of the TAR has often been postulated as the main reason for the high incidence of these complications. It remains unclear to what extent malalignment of the TAR affects the stresses at the bone-implant interface. Therefore, this study aims to elucidate the effect of TAR malalignment on the contact stresses on the bone-implant interface, thereby gaining more understanding of the potential role of malalignment in TAR failure. FE models of the neutrally aligned as well as malaligned CCI Evolution TAR implant (Van Straten Medical) were developed. Separate models were developed for the tibial and talar segment, with the TAR components in neutral alignment and 5° and 10° varus, valgus, anterior and posterior malalignment, resulting in a total of 9 differently aligned TAR models. Loading conditions of the terminal stance phase of the gait cycle, when the force on the ankle joint is highest (5.2x body weight), were applied. Peak and mean contact pressure and shear stress at the bone-implant interface were analyzed. Also, stress distributions on the bone-implant interface were visualized. In the neutrally aligned tibial and talar TAR models, peak contact pressures of respectively 98.4 MPa and 68.2 MPa, and shear stresses of respectively 49.3 MPa and 39.0 MPa were found. TAR malalignment increases peak contact pressure and shear stress on the bone-implant interface. A maximum peak contact pressure of 177 MPa was found for the 10° valgus malaligned tibial component and the highest shear stress found was 98.5 MPa for the 10° posterior malaligned talar model. Upon TAR malalignment contact stresses increase substantially, suggesting that proper orientation of the TAR is needed to minimize peak stresses on the bone-implant interface. This is in line with previous studies, which state that malalignment considerably increases bone strains, micromotion, and internal TAR contact pressures, which might increase the risk of TAR failure. Further research is needed to investigate the relationship between increased contact stresses at the bone-implant interface and TAR failure

Pelvic bone defect in patients with severe congenital dysplasia of the hip (CDH) lead to abnormalities in lumbar spine and lower limb alignment that can determine total hip arthroplasty (THA) patients' outcome. These variables may be different in uni- or bilateral CDH. We compared the clinical outcome and the spinopelvic and lower limb radiological changes over time in patients undergoing THA due to uni- or bilateral CHD at a minimum follow-up of five years. Sixty-four patients (77 hips) undergoing THA due to severe CDH between 2006 and 2015 were analyzed: Group 1 consisted of 51 patients with unilateral CDH, and group 2, 113 patients (26 hips) with bilateral CDH. There were 32 females in group 1 and 18 in group 2 (p=0.6). The mean age was 41.6 years in group 1 and 53.6 in group 2 (p<0.001). We compared the hip, spine and knee clinical outcomes. The radiological analysis included the postoperative hip reconstruction, and the evolution of the coronal and sagittal spinopelvic parameters assessing the pelvic obliquity (PO) and the sacro-femoro-pubic (SFP) angles, and the knee mechanical axis evaluating the tibio-femoral angle (TFA). At latest follow-up, the mean Harris Hip Score was 88.6 in group 1 and 90.7 in group 2 (p=0.025). Postoperative leg length discrepancy of more than 5 mm was more frequent in group 1 (p=0.028). Postoperative lumbar back pain was reported in 23.4% of the cases and knee pain in 20.8%, however, there were no differences between groups. One supracondylar femoral osteotomy and one total knee arthroplasty were required. The radiological reconstruction of the hip was similar in both groups. The PO angle improved more in group 1 (p=0.01) from the preoperative to 6-weeks postoperative and was constant at 5 years. The SFP angle improved in both groups but there were no differences between groups (p=0.5). 30 patients in group 1 showed a TFA less than 10º and 17 in group 2 (p=0.7). Although the clinical outcome was better in terms of hip function in patients with bilateral CDH than those with unilateral CDH, the improvement in low back and knee pain was similar. Patients with unilateral dysplasia showed a better correction of the PO after THA. All spinopelvic and knee alignment parameters were corrected and maintained over time in most cases five years after THA

It has been recently being investigated how the pressure distribution beneath the foot points to the active usage of the foot in standing adults. Nevertheless, it offers new perspectives in postural research by introducing foot-triggered sensory-motor control strategies in quiet standing dynamics. Furthermore, the spatiotemporal evolution of physiological postural control strategies has not clearly been identified yet. Thus, we have chosen developmental aspects of the infant's postural adjustments as a media to explore learning of biped standing. This study investigates developmental changes in active usage of a contact surface and pressure distribution beneath infants’ foot during learning of upright posture. We started studying longitudinally on 22 female and 22 male infants at their 12.5. th. months (1. st. trimester, T1) and kept on screening the same subjects at every three months (19 females and 12 males at 15.5. th. months (T2), 17 females and 7 males at 18.4. th. months (T3)), during their normal checkup appointments in Gazi University Hospital, Social Pediatrics Department-Ankara/Turkey. Each trial was fulfilled by an infant standing on a pressure pad placed on top of a force plate to collect the pressure distribution data beneath the feet for 15 sec at T1, and 25-sec long duration at T2 and T3 and was repeated at least three times. During the data collection, infants’ parents were beside them trying to get infants’ attention towards themselves preventing them from being distracted and/or moving and walking around. The data collection setup additionally contained one camera for videotaping the infants’ reactions. Our main research interest in this study was to explore the spatiotemporal evolution of the behavioral characteristics of human postural sway. We expected to monitor the developmental changes at an infant's standing experience during their 2. nd. -year epoch through time-frequency domain analyses and explorative/exploitative informatics’ metrics. We computed Center of Pressure (CoP) time signal from the data collected by the force plate and the pressure pad. In time domain, mean and the variance at the CoP time signal were estimated in both antero-posterior (CoPx) and medio-lateral (CoPy) directions. In the frequency domain, 50% and 95% power frequency, centroidal frequency (CF), and frequency dispersion were calculated. We observed substantial developmental changes in every trimester, each being comparable with the previous one, which points to infants experiencing a major developmental milestone that can be noticed considerably even in the shorter time intervals. The phase plane analysis performed through the time signals and their time derivatives (estimated velocity of CoPx and CoPy) revealed a shrinkage in the characteristic pattern observed through the following epochs. One-Way ANOVA analysis demonstrated significant differences in 50% and 95% power and centroidal frequency of CoPx (p=0.001, p=0.000, p=0.000) and CoPy (p=0.002, p=0.000, p=0.000) respectively. Further, post hoc analyses demonstrated a significant difference at T1 compared against T2 and T3 for all three frequency domain metrics. Particularly speaking, CF dropped from 2.39 to 1.65 Hz, and from 2.86 to 1.70 Hz for CoPx and CoPy respectively, while passing from T1 to T2. The current status of this research managed to grasp the developmental aspects of infant standing through frequency domain metrics and reconstructed phase space analysis up to their 18 months old

Introduction and Objective. Difficult primary total knee arthroplasty (TKA) and revision TKA are high demanding procedures. Joint exposure is the first issue to face off, in order to achieve a good result. Aim of this study is to evaluate the clinical and radiological outcomes of a series of patients, who underwent TKA and revision TKA, where tibial tubercle osteotomy (TTO) was performed. Materials and Methods. We retrospectively reviewed a cohort of 79 consecutives TKAs where TTO was performed, from our Institution registry. Patients were assessed clinically and radiographically at their last follow-up (mean, 7.4 ± 3.7 years). Clinical evaluation included the Knee Society Score (KSS), the pain visual analogue scale (VAS), and range of motion. Radiological assessment included the evaluation of radiolucent lines, osteolysis, cortical bone hypertrophy, time of bone healing of the TTO fragment, and the hardware complication. Results. KSS raised from 40.7 ± 3.1 to 75 ± 4.3 (p < 0.0001). Knee flexion increased from 78.7 ± 9.9° to 95.0 ± 9.5° (p < 0.0001), and VAS improved from 7.9 ± 0.9 to 3.8 ± 1 (p < 0.0001). No signs of loosening or evolutive radiolucency lineswere found. Osteolytic areas around the stem were detected. No significant association was found between the implant design and the outcomes, while aseptic loosening showed significantly better results. Complications were: 4 painful hardware, 3 late periprosthetic infections, 1 extension lag of 5°, and 3 flexion lag. Conclusions. Our experience suggests the use of TTO to improve the surgical approach in difficult primary TKA or revision TKA. A strict surgical technique leads to good results with low risk of complications

In vivo animal experimentation has been one of the cornerstones of biological and biomedical research, particularly in the field of clinical medicine and pharmaceuticals. The conventional in vivo model system is invariably associated with high production costs and strict ethical considerations. These limitations led to the evolution of an ex vivo model system which partially or completely surmounted some of the constraints faced in an in vivo model system. The ex vivo rodent bone culture system has been used to elucidate the understanding of skeletal physiology and pathophysiology for more than 90 years. This review attempts to provide a brief summary of the historical evolution of the rodent bone culture system with emphasis on the strengths and limitations of the model. It encompasses the frequency of use of rats and mice for ex vivo bone studies, nutritional requirements in ex vivo bone growth and emerging developments and technologies. This compilation of information could assist researchers in the field of regenerative medicine and bone tissue engineering towards a better understanding of skeletal growth and development for application in general clinical medicine. Cite this article: A. A. Abubakar, M. M. Noordin, T. I. Azmi, U. Kaka, M. Y. Loqman. The use of rats and mice as animal models in ex vivo bone growth and development studies. Bone Joint Res 2016;5:610–618. DOI: 10.1302/2046-3758.512.BJR-2016-0102.R2

Biomechanical interpretations of bone adaptation in biological reconstructions following bone tumors would be crucial for orthopedic oncologists, particularly if based on quantitative observations. This would help to plan for surgical treatments, rehabilitative programs and communication with the patients. In particular, outcomes of the Capanna technique, which combines bone allograft and vascularized fibula autograft, lead to stable and durable reconstructions [1, 2], and different remodeling patterns have been described [3] as a response to mechanical loading. However, there are several events that are not understood and require a biomechanical interpretation, as the evolution patterns can evolve towards conditions that threaten the strength of the reconstruction. We aimed to (i) analyze the biomechanical adaptation of a femoral reconstruction after Ewing sarcoma, in terms of morphological and densitometric evolution of bone from CT data, internal loads acting on the bone during movement, mechanical competence of the reconstruction, and (ii) relate in-progress bone resorption to the mechanical stimulus induced by different motor activities. Eight CT datasets of a patient (8 yrs at surgery using the Capanna technique) during 76-month follow-up were available. The evolution of bone morphology, density and moments of inertia was quantified. At the last control, the patient underwent gait analysis (walking, chair rise/sit, stair ascent/descent, squat). We created a multiscale musculoskeletal and finite element model from CT scans and motion analysis data at the end of follow-up, using state-of-the-art modeling workflows [4, 5], to analyze muscle and joint loads, and to compare the mechanical competence of the reconstructed bone with the contralateral limb, in the current real condition and in a possible revision surgery that removed proximal screws. Although there were no reconstruction complications and osteo-fusion with intense remodeling between allograft and autograft was shown, there was a progressive decrease in allograft cortical thickness and density. There were strategies of muscle coordination that led to differences in joint loads between limbs more marked in more demanding motor activities, and generally larger in the contralateral limb. The operated femur presented a markedly low ratio of physiological strain due to load-sharing with the metal implant, particularly in the lateral aspect. A possible revision surgery removing the three most proximal screws would help restore a physiological strain configuration, while the safety of the reconstruction would not be threatened. We suggest that bone resorption is related to load-sharing and to the internal forces exerted during movement, and the mechanical stimulus should be improved by adopting modifications in the surgical treatment and by promoting physical therapy aimed at specific muscle strengthening

Spondylolisthesis is common recognized spine pathology. A lot of studies targeted spondylolisthesis in the recent years, few of which have made a major influential impact on the clinical practice. To the extent our knowledge this is the first study to highlight and analyze the top 100 cited articles on spondylolisthesis through a systematic search strategy used previously in published studies in different medical specialty. The aim of this study is to identify the most cited studies on spondylolisthesis and report their impact in spine field. Thomson Reuters Web of Science-Science Citation Index Expanded was searched using title-specific search “spondylolisthesis”. All studies published in English language between 1900 and 2019 were included with no restrictions. The top 100 cited articles were identified using “Times cited” arranging articles from high to low according to citation count. Further analysis was made to obtain the following items: Article title, author's name and specialty, country of origin, institution, journal of publication, year of publication, citations number, study design. The citation count of the top 100 articles ranged from 69 to 584. All published between 1950 – 2016. Among 20 journals, Spine had the highest number of articles 47, with citation number of 5964 out of 13644. Second ranked was Journal of Bone and Joint Surgery with 16 articles and a total citation of 3187. In respect to the primary author's specialty, Orthopedic surgeons contributed to the majority of top 100 list with 82 articles, Neurosurgery was the second specialty with 10 articles. United states had produced more than half of the list by 59 articles. England was the second country with 7 articles. Surgical management of lumbar spondylolisthesis was the most common discussed topic. This article identifies the top 100 influential papers on spondylolisthesis and recognizes an important aspect of knowledge evolution served by leading researchers as they guide today's clinical decision making in spondylolisthesis

Objective. In order to effectively utilize mechanical signals in the clinic as a non-drug-based intervention to improve cartilage defect regeneration after surgical treatment, it is essential to identify crucial components of the cellular response that are typical to the anabolic process. The mechanisms behind the effect of mechanical stimulation are, however, not fully understood and the signaling pathways involved in the anabolic response of chondrocytes to mechano-transduction are not well described. Therefore, a genome-wide identification of mechano-regulated genes and candidate pathways in human chondrocytes subjected to a single anabolic loading episode was performed in this study and time evolution and re-inducibility of the response was characterized. Design. Osteochondral constructs consisting of a chondrocyte-seeded collagen-scaffold connected to β-tricalcium-phosphate were pre-cultured for 35 days and subjected to dynamic compression (25% strain, 1 Hz, 9×10 minutes over 3h) before microarray-profiling was performed. Proteoglycan synthesis was determined by 35S-sulfate-incorporation over 24 hours. Protein alterations were determined by Western blotting. Results. Cell viability and hardness of constructs were unaltered by dynamic compression while proteoglycan synthesis was significantly stimulated (1.45-fold, p=0.016). Among 115 significantly regulated genes, 114 were up-regulated, 48 of them ≥ two-fold. AP-1-relevant transcription factors FOSB and FOS strongly increased in line with elevated ERK1/2-phosphorylation and rising MAP3K4 expression. Expression of proteoglycan-synthesizing enzymes CHSY1 and GALNT4 was load-responsive as were factors associated with the MAPK-, TGF-β-, calcium-, retinoic-acid-, Wnt- and Notch-signaling pathway which were significantly altered. SOX9, BMP4 and BMP6 levels rose significantly also after multiple loading episodes at daily intervals even at the 14th cycle with no indication for desensitation. Canonical pSmad2/3 and pSmad1/5/9-signalling was apparently unaltered. Conclusion. This study associates raising SOX9 protein levels, pERK stimulation and increased CHSY1 expression with anabolic loading of chondrocytes and suggests that more pathways than so far anticipated apparently work together in a complex network of stimulators and feedback-regulators. Knowledge on time evolution of mechanosensitive indicators responding to anabolic loading is crucial to maximize cartilage matrix-deposition for the generation of high-level cartilage replacement tissue

Financial and human cost effectiveness is an increasing evident outcome measure of surgical innovation. Considering the human element, the aim is to restore the individual to their “normal” state by sparing anatomy without compromising implant performance. Gait lab studies have shown differences between different implants at top walking speed, but none to our knowledge have analysed differing total hip replacement patients through the entire range of gait speed and incline to show differences. The purpose of this gait study was to 1) determine if a new short stem femoral implant would return patients back to normal 2) compare its performance to established hip resurfacing and long stem total hip replacement (THR) implants. 110 subjects were tested on an instrumented treadmill (Kistler Gaitway, Amherst, NY), 4 groups (short-stem THR, long-stem THR, hip resurfacing and healthy controls) of 28, 29, 27, and 26 respectively. The new short femoral stem patients (Furlong Evolution, JRI) were taken from the ongoing Evolution Hip trial that have been tested on the treadmill with minimum 12months postop. The long stem total hip replacements and hip resurfacing groups were identified from out 800 patient gait database. They were only chosen if they were 12 months postop and had no other joint disease or medical comorbidities which would affect gait performance. All subjects were tested through their entire range of gait speeds and incline after having a 5 minute habituation period. Speed intervals were at 0.5kms increments until maximum walking speed achieved and inclines at 4kms for 5, 10, 15%. At all incremental intervals of speed, the vertical component of the ground reaction forces, center of pressure and temporal measurements were collected for both limbs with a sampling frequency of 100Hz. Body weight scaling was applied to correct for mass differences and a symmetry index to compare the implanted hip to the contralateral normal hip. All variables for each subject group were compared to each other using an analysis of variance (ANOVA) with Tukey post hoc test with significance set at α=0.05. The four experimental groups were reasonably matched for demographics and the implant groups for PROMs. Hip resurfacing had a clear top walking speed advantage, but when assessing the symmetry index on all speeds and incline, all groups were not significantly different. Push-off and step length was statistically less favourable for the short/long THR group (p=0.005–0.05) depending on speed/incline. The primary aim of this study was determine if implant design affected gait symmetry and performance. Interestingly, irrespective of implant design, symmetry with regards to weight acceptance, impulse, push-off and step length was returned to normal when comparing to healthy controls. However individual implant performance on the flat and incline, showed inferior (p<0.05) push-off force and step length in the short stem and long stem THR groups when compared to controls. Age and gender may have played a part for the short stem group. It appears that the early gait outcomes for the short stem device are promising. Assessment at the 3 year mark should be conclusive

Human mesenchymal stem cells (MSCs) are multipotent stem cells with the ability to differentiate into mesoderm-type cells such as osteoblasts, chondroblast, tenocytes etc. They can be retrieved by different sources, but the number of cells obtained suggested the adipose tissue as a primary harvest site of MSCs. Cells can be harvested using the Coleman procedure, obtaining stromal vascular fraction (SVF), enriched with MSCs, after collagenase digestion. The availability of SVF storage has been envisioned for multiple treatments of the degenerated tissue. Indeed, the use of SVF has been introduced into clinical trials for tissue regeneration for orthopaedic patients. Difficulties of a selective delivery of SVF locally have been previously discussed. Thus, the use of biological scaffolds in order to better localize SVF in the tissue site has been studied. The methodological evolution for the use of SVF in the best possible biological conditions is a milestone for good clinical results

Biomimicry is defined as the design and production of materials, structures, and systems that are modelled on biological entities and processes. Within the medical device sector, biomimicry uses an ecological standard to judge the “rightness” of biomaterial components and devices. After 3.8 billion years of evolution, nature has learned what works, what is appropriate, and what lasts. Biomimicry is a new way of viewing and valuing nature, and it introduces an era based not on what we can extract from the natural world, but on what we can learn from it. Original design manufacturing biomaterial projects that leverage the practice of biomimicry will be discussed. Both natural and synthetic polymer platforms will be reviewed for soft tissue and hard tissue applications. Given the complexity of musculoskeletal tissue structures, the key challenge is identifying the most appropriate materials and forms for recapitulating the native function in a tissue scaffold design. The general field of biomimicry will be reviewed along with specific examples in the regenerative medicine sector