The use of joint-preserving surgery of the hip has been largely abandoned since the introduction of total hip replacement. However, with the modification of such techniques as pelvic osteotomy, and the introduction of intracapsular procedures such as surgical hip dislocation and arthroscopy, previously unexpected options for the surgical treatment of sequelae of childhood conditions, including developmental dysplasia of the hip, slipped upper femoral epiphysis and Perthes’ disease, have become available. Moreover, femoroacetabular impingement has been identified as a significant aetiological factor in the development of osteoarthritis in many hips previously considered to suffer from primary osteoarthritis. As mechanical causes of degenerative joint disease are now recognised earlier in the disease process, these techniques may be used to decelerate or even prevent progression to osteoarthritis. We review the recent development of these concepts and the associated surgical techniques. Cite this article: Bone Joint J 2014;96-B:5–18

Plantar fasciitis (PF) is one of the widespread conditions causing hindfoot pain. The most common presenting symptoms are functional limitation and pain (first step and activity) on plantar surface of the foot. The non-operative treatments provide complete resolution of pain in 90% of patients, but functional limitation still remains as a risk factor for recurrency of PF. Although the number of non-operative treatment options showing efficacy on pain and functional limitation are excessive, the evidences are limited for functional limitation. Additionally, Mulligan mobilization with movement (MMWM) in Chronic Plantar Fasciitis has been poorly studied in the literature. According to these findings, the study was aimed to determine effectiveness of Mulligan mobilization with movement on Chronic Plantar Fasciitis. A total of 25 patients (40 feet) with chronic PF were included in the study. The patients were randomly divided into Mulligan concept rehabilitation group (PF-M, n=20 feet) and Home Rehabilitation group (PF-H, n=20 feet). (MMWM), Foot and ankle exercises program were applied to PF-M, twice a week totally 8 week (16 sessions) and foot- ankle exercises as a home program were given for PF-H, 8 weeks. The range of motion (ROM) for dorsiflexion and plantar flexion was measured by using a manual goniometer. Pain, disability and activity restriction were assessed by Foot Function Index (FFI) . The first step morning pain was evaluated by Visual Analogue Scale (VAS) and Kinesiophobia was also reported by using Tampa Scale (TSK). Patients were evaluated at baseline and 8 weeks. FFI, VAS, TSK, ROM values improved in all groups (intragroup variability) at 8th week (P < .05). The other result indicated that ROM values for DF and PF and TSK scores in PF-M had more significant improvement than PF-H (p<.05). To the best of our knowledge this is the first randomised controlled trial for investigating Mulligan Concept efficiancy on chronic PF. Both Mulligan mobilization with movement (MMWM) and exercise protocols are effective for chronic PF. Furthermore, The Mulligan concept seems more effective treatment option in reducing kinesiophobia and improving functional capacity

Background. The anatomy of the human knee is very different than the tibiofemoral surface geometry of most modern total knee replacements (TKRs). Many TKRs are designed with simplified articulating surfaces that are mediolaterally symmetrical, resulting in non-natural patterns of motion of the knee joint [1]. Recent orthopaedic trends portray a shift away from basic tibiofemoral geometry towards designs which better replicate natural knee kinematics by adding constraint to the medial condyle and decreasing constraint on the lateral condyle [2]. A recent design concept has paired this theory with the concept of guided kinematic motion throughout the flexion range [3]. The purpose of this study was to validate the kinematic pattern of motion of the surface-guided knee concept through in vitro, mechanical testing. Methods. Prototypes of the surface-guided knee implant were manufactured using cobalt chromium alloy (femoral component) and ultra-high molecular weight polyethylene (tibial component). The prototypes were installed in a force-controlled knee wear simulator (AMTI, Watertown, MA) to assess kinematic behavior of the tibiofemoral articulation (Figure 1). Axial joint load and knee flexion experienced during lunging and squatting exercises were extracted from literature and used as the primary inputs for the test. Anteroposterior and internal-external rotation of the implant components were left unconstrained so as to be passively driven by the tibiofemoral surface geometry. One hundred cycles of each exercise were performed on the simulator at 0.33 Hz using diluted bovine calf serum as the articular surface lubricant. Component motion and reaction force outputs were collected from the knee simulator and compared against the kinematic targets of the design in order to validate the surface-guided knee concept. Results. Under deep flexion conditions of up to 140° of squatting the surface-guided knee implants were found to undergo a maximum of 22.2° of tibial internal rotation and 20.4 mm of posterior rollback on the lateral condyle. Pivoting of the knee joint was centered about the highly congruent medial condyle which experienced only 1.6 mm of posterior rollback. Experimental results were within 2° (internal-external rotation) and 1 mm (anteroposterior translation) agreement with the design target throughout the applied exercises (Figure 2). Conclusion. The results of this test confirm that by combining a constrained medial condyle with guiding geometry on the lateral condyle, deep knee flexion activities of up to 140° can be performed while maintaining near-natural kinematics of the knee joint. The authors believe that the tested surface-guided implant concept is a significant step toward the development of novel TKR which allows a greater range of motion and could improve the quality of life for active patients undergoing knee replacement. For any figures or tables, please contact the authors directly

Introduction. The regionalisation of major trauma in the UK has significantly improved outcomes for patients with severe, lower limb injuries. Chronic pain after complex lower limb injuries is well documented, but seems to remain a problem despite better clinical and radiological outcomes. We hypothesised that pain was mediated through the saphenous nerve, especially as most tibial injuries affected the soft tissues medially. As a proof of concept, we undertook adductor canal blocks to understand pain aetiology. Materials & Methods. Patients with chronic pain following complex lower limb trauma or congenital deformity correction have been selected and underwent an adductor canal block by one of our trauma anaesthetist that specialises in this procedure. Their outcomes were recorded in their clinical records and patients were contacted by phone to document their experiences. Results. 14 patients with chronic, treatment refractory lower limb pain who were being managed in our orthoplastics clinic following complex, lower limb trauma were identified. Six of those patients had required plastic coverage. Of these 14 patients, all stated their pain completely resolved after the procedure and then returned between 24 hours and 4 weeks after the procedure. Two patients underwent a saphenous nerve diversion after conduction of the blocks, reporting subsequent resolution of their complaints. Conclusions. As a proof of concept, we report that the saphenous nerve underlies chronic pain in patients with complex lower limb injuries. An adductor canal block is an effective diagnostic tool for these patients. Saphenous diversion may offer a permanent solution in patients who respond well to saphenous nerve block. A prospective study is planned to objectively measure pain and quality of life scores after treatment of complex injuries and pre and post adductor canal block

Nerve transfer is an emerging treatment to restore upper limb function in people with tetraplegia. The objective of this study is to examine if a flexible collage sheet (FCS) can act as epineurial-like substitute to promote nerve repair in nerve transfer. A preclinical study using FCS was conducted in a rat model of sciatic nerve transection. A prospective case series study of nerve transfer was conducted in patients with C5-C8 tetraplegia who received nerve transfer to restore upper limb function. Motor function in the upper limb was assessed pre-treatment, and at 6-,12-, and 24-months post-treatment. Macroscopic assessment in preclinical model showed nerve healing by FCS without encapsulation or adhesions. Microscopic examination revealed that a new, vascularised epineurium-like layer was observed at the FCS treatment sites, with no evidence of inflammatory reaction or nerve compression. Treatment with FCS resulted in well-organised nerve fibres with dense neurofilaments distal to the coaptation site. Axon counts performed proximal and distal to the coaptation site showed that 97% of proximal axon count of myelinated axons regenerated across the coaptation site after treatment with CND. In the proof of concept clinical study 17 nerve transfers were performed in five patients. Nerve transfers included procedures to restore triceps function (N=4), wrist/finger/thumb extension (N=6) and finger flexion (N=7). Functional motor recovery (MRC ≥3) was achieved in 76% and 88% of transfers at 12 and 24 months, respectively. The preclinical study showed that FCS mimics epineurium and enable to repair nerve resembled to normal nerve tissue. Clinical study showed that patients received nerve transfer with FCS experienced consistent and early return of motor function in target muscles. These results provide proof of concept evidence that CND functions as an epineurial substitute and is promising for use in nerve transfer surgery

Mixed Reality has the potential to improve accuracy and reduce required dissection for the performance of peri-acetabular osteotomy. The current work assesses initial proof of concept of MR guidance for PAO. A PAO planning module, based on preoperative computed tomography (CT) imaging, allows for the planning of PAO cut planes and repositioning of the acetabular fragment. 3D files (holograms) of the cut planes and native and planned acetabulum positions are exported with the associated spatial information. The files are then displayed on mixed reality head mounted device (HoloLens2, Microsoft) following intraoperative registration using an FDA-cleared mixed reality application designed primary for hip arthroplasty (HipInsight). PAO was performed on both sides of a bone model (Pacific Research). The osteotomies and acetabular reposition were performed in accordance with the displayed holograms. Post-op CT imaging was performed for analysis. Cutting plane-accuracy was evaluated using a best-fit plane and 2D angles (°) between the planned and achieved supra (SA)- and retroacetabular (RA) osteotomy and retroacetabular and ischial osteotomies (IO) were measured. To evaluate the accuracy of acetabular reorientation, we digitized the acetabular rim and calculated the acetabular opening plane. Absolute errors of planned and achieved operative inclination and anteversion (°) of the acetabular fragment, as well as 3D lateral-center-edge (LCE) angles were calculated. The mean absolute difference between the planned and performed osteotomy angles was 3 ± 3°. The mean absolute error between planned and achieved operative anteversion and inclination was 1 ± 0° and 0 ± 0° respectively. Mean absolute error between planned and achieved 3D LCE angle was 0.5 ± 0.7°. Mixed-reality guidance for the performance of pelvic osteotomies and acetabular fragment reorientation was feasible and highly accurate. This solution may improve the current standard of care by enabling reliable and precise reproduction of the desired acetabular realignment

Aim. Reconstruction of composite soft-tissue defects with extensor apparatus deficiency in patients with periprosthetic joint infection (PJI) of the knee is challenging. We present a single-centre multidisciplinary orthoplastic treatment concept based on a retrospective outcome analysis over 20 years. Method. One-hundred sixty-seven patients had PJI after total knee arthroplasty. Plastic surgical reconstruction of a concomitant perigenicular soft-tissue defect was indicated in 49 patients. Of these, seven presented with extensor apparatus deficiency. Results. One patient underwent primary arthrodesis and six patients underwent autologous reconstruction of the extensor apparatus. The principle to reconstruct missing tissue ‘like with like’ was thereby favoured: Two patients with a wide soft-tissue defect received a free anterolateral thigh flap with fascia lata; one patient with a smaller soft-tissue defect received a free sensate, extended lateral arm flap with triceps tendon; and three patients received a pedicled medial sural artery perforator gastrocnemius flap, of which one with Achilles tendon. Despite good functional results 1 year later, long-term follow-up revealed that two patients had to undergo knee arthrodesis because of recurrent infection and one patient was lost to follow-up. In parts, results have been published under doi: 10.7150/jbji.47018. Conclusions. A treatment concept and its rationale, based on a single-centre experience, is presented. It differentiates between various types of soft-tissue defects and shows reconstructive options following the concept to reconstruct ‘like with like’. Despite good results 1 year postoperatively, PJI of the knee with extensor apparatus deficiency remains a dreaded combination with a poor long-term outcome

Aim. To provide proof of concept in an in vivo animal model for the prevention of prosthetic joint infection prevention using electric fields along with conventional antibiotic prophylaxis. Corresponding Author: Marti Bernaus. Method. First, we standardized the animal model to simulate implant contamination during the surgical procedure. We then implanted cobalt-chrome prostheses adapted to both knees of two New Zealand White rabbits, under standard aseptic measures and antibiotic prophylaxis with cefazolin. Prior to implantation, we immersed the prostheses in a 0.3 McFarland inoculum of S. aureus (ATCC 25923) for 30 seconds. In the first animal (control), the joint was directly closed after washing with saline. In the second animal (case), both prostheses were treated with electric current pulses for 30 seconds, washed with saline, and the joint was closed. After 72 hours, both animals were reoperated for the collection of periprosthetic tissue and bone samples, and prosthesis removal. In all samples, we performed quantitative cultures prior to vortexing and sonication, as well as prolonged cultures of the sonication broth. We confirmed the absence of contamination by identification with MALDI-TOF (VITEK-MS) and automated antibiotic susceptibility testing of the isolated colonies (VITEK-2). Results. In the “control” animal, we isolated S. aureus in all studied samples. The bacterial count expressed as log10 (cfu/cm2) in the prostheses of the right and left legs was 9.38 and 8.86, respectively. The bacterial count expressed as log10 (cfu/mL) in bone and periprosthetic tissue biopsies was 2.70 and 2.72 in the right leg and 3.24 and 3.87 in the left leg, respectively. In the “case” animal, where an electric field was applied to the implant after placement in addition to cefazolin prophylaxis, all samples (prosthesis, bone, and periprosthetic tissue) were negative, and no isolation of the inoculated strain of S. aureus was obtained after incubation of the sonication broth for 14 days. Conclusions. This in vivo model suggests the potential effectiveness of applying an electric field to a prosthetic implant in combination with cefazolin for the prevention of PJI development, after exposure of the implant to an inoculum of S. aureus (ATCC 25923). Our findings need to be confirmed using a larger sample size

Objectives. CT-based three-column classification (TCC) has been widely used in the treatment of tibial plateau fractures (TPFs). In its updated version (updated three-column concept, uTCC), a fracture morphology-based injury mechanism was proposed for effective treatment guidance. In this study, the injury mechanism of TPFs is further explained, and its inter- and intraobserver reliability is evaluated to perfect the uTCC. Methods. The radiological images of 90 consecutive TPF patients were collected. A total of 47 men (52.2%) and 43 women (47.8%) with a mean age of 49.8 years (. sd. 12.4; 17 to 77) were enrolled in our study. Among them, 57 fractures were on the left side (63.3%) and 33 were on the right side (36.7%); no bilateral fracture existed. Four observers were chosen to classify or estimate independently these randomized cases according to the Schatzker classification, TCC, and injury mechanism. With two rounds of evaluation, the kappa values were calculated to estimate the inter- and intrareliability. Results. The overall inter- and intraobserver agreements of the injury mechanism were substantial (κ. inter. = 0.699, κ. intra. = 0.749, respectively). The initial position and the force direction, which are two components of the injury mechanism, had substantial agreement for both inter-reliability or intrareliability. The inter- and intraobserver agreements were lower in high-energy fractures (Schatzker types IV to VI; κ. inter. = 0.605, κ. intra. = 0.721) compared with low-energy fractures (Schatzker types I to III; κ. inter. = 0.81, κ. intra. = 0.832). The inter- and intraobserver agreements were relatively higher in one-column fractures (κ. inter. = 0.759, κ. intra. = 0.801) compared with two-column and three-column fractures. Conclusion. The complete theory of injury mechanism of TPFs was first put forward to make the TCC consummate. It demonstrates substantial inter- and intraobserver agreement generally. Furthermore, the injury mechanism can be promoted clinically. Cite this article: B-B. Zhang, H. Sun, Y. Zhan, Q-F. He, Y. Zhu, Y-K. Wang, C-F. Luo. Reliability and repeatability of tibial plateau fracture assessment with an injury mechanism-based concept. Bone Joint Res 2019;8:357–366. DOI: 10.1302/2046-3758.88.BJR-2018-0331.R1

Aims. Plating displaced proximal humeral fractures is associated with a high rate of screw perforation. Dynamization of the proximal screws might prevent these complications. The aim of this study was to develop and evaluate a new gliding screw concept for plating proximal humeral fractures biomechanically. Methods. Eight pairs of three-part humeral fractures were randomly assigned for pairwise instrumentation using either a prototype gliding plate or a standard PHILOS plate, and four pairs were fixed using the gliding plate with bone cement augmentation of its proximal screws. The specimens were cyclically tested under progressively increasing loading until perforation of a screw. Telescoping of a screw, varus tilting and screw migration were recorded using optical motion tracking. Results. Mean initial stiffness (N/mm) was 581.3 (. sd. 239.7) for the gliding plate, 631.5 (. sd. 160.0) for the PHILOS and 440.2 (. sd. 97.6) for the gliding augmented plate without significant differences between the groups (p = 0.11). Mean varus tilting (°) after 7500 cycles was comparable between the gliding plate (2.6; . sd. 1.9), PHILOS (1.2; . sd. 0.6) and gliding augmented plate (1.7; . sd. 0.9) (p = 0.10). Similarly, mean screw migration(mm) after 7500 cycles was similar between the gliding plate (3.02; . sd. 2.85), PHILOS (1.30; . sd. 0.44) and gliding augmented plate (2.83; . sd. 1.18) (p = 0.13). Mean number of cycles until failure with 5° varus tilting were 12702 (. sd. 3687) for the gliding plate, 13948 (. sd. 1295) for PHILOS and 13189 (. sd. 2647) for the gliding augmented plate without significant differences between the groups (p = 0.66). Conclusion. Biomechanically, plate fixation using a new gliding screw technology did not show considerable advantages in comparison with fixation using a standard PHILOS plate. Based on the finding of telescoping of screws, however, it may represent a valid approach for further investigations into how to avoid the cut-out of screws. Cite this article: Y. P. Acklin, I. Zderic, J. A. Inzana, S. Grechenig, R. Schwyn, R. G. Richards, B. Gueorguiev. Biomechanical evaluation of a new gliding screw concept for the fixation of proximal humeral fractures. Bone Joint Res 2018;7:422–429. DOI: 10.1302/2046-3758.76.BJR-2017-0356.R1

Fracture fixation has advanced significantly with the introduction of locked plating and minimally invasive surgical techniques. However, healing complications occur in up to 10% of cases, of which a significant portion may be attributed to unfavorable mechanical conditions at the fracture. Moreover, state-of-the-art plates are prone to failure from excessive loading or fatigue. A novel biphasic plating concept has been developed to create reliable mechanical conditions for timely bone healing and simultaneously improve implant strength. The goal of this study was to test the feasibility and investigate the robustness of fracture healing with a biphasic plate in a large animal experiment. Twenty-four sheep underwent a 2mm mid-diaphyseal tibia osteotomy stabilized with either the novel biphasic plate or a control locking plate. Different fracture patterns in terms of defect location and orientation were investigated. Animals were free to fully bear weight during the post-operative period. After 12 weeks, the healing fractures were evaluated for callus formation using micro-computer tomography and strength and stiffness using biomechanical testing. No plate deformation or failures were observed under full weight bearing with the biphasic plate. Osteotomies stabilized with the biphasic plate demonstrated robust callus formation. Torsion tests after plate removal revealed no statistical difference in peak torsion to failure and stiffness for the different fracture patterns stabilized with the biphasic plate. However, the biphasic plate group specimens were 45% stronger (p=0.002) and 48% stiffer (p=0.007) than the controls. The results of this large animal study demonstrate the clinical potential of this novel stabilization concept

Culture of multiple intraoperative tissue samples is the standard of microbiological diagnosis of prosthetic joint infections. Recently, improved sensitivity of using prosthesis sonication method and molecular techniques has been reported in the literature. However, collecting the removed prosthesis as well as additional specimens for molecular analysis is not straightforward for the surgeons and assistants in the operation theatre. Our All-in-a-Box concept addresses the need for simple and unambiguous sampling of clinical specimens in the operating theatre, and to overcome the variation in sampling technique within and between surgical teams and across different hospitals. The All-in-a-Box concept was developed in close cooperation between surgeons, their operating assistants, clinical microbiologists and molecular biologists in order to ensure the concept is easily implemented in the operating theatre, achieving high completeness, and being well preserved all the way to the laboratory. All needed equipment, vials and forms are collected in a single box, and corresponding items are clearly color coded to further reduce the likelihood of confusion. Boxes are designed to address the specific needs for either routine diagnosis or special demands as in clinical studies. Their design is based on large experience in connection with diagnosis of joint prosthesis-related infections. Downstream SOPs for sample processing are included in the All-in-a-box concept and specimens can subsequently be analyzed in parallel by culturing and molecular methods. We have implemented this concept in two large research projects, we received 1508 (89%) of 1685 scheduled samples during the 2-year project period in the first project despite several different surgical teams and hospitals, while the other project is still ongoing. All-in-a-Box is useful concept to improve the completeness of routine sampling for microbial analysis

Methods. Between 2005 and 2012, 50 patients (23 female, 27 male) with nonunion of the humeral shaft were included in this retrospective study. The mean age was 51.3 years (14 to 88). The patients had a mean of 1.5 prior operations (. sd. 1.2;1 to 8). All patients were assessed according to a specific risk score in order to devise an optimal and individual therapy plan consistent with the Diamond Concept. In 32 cases (64%), a change in the osteosynthesis to an angular stable locking compression plate was performed. According to the individual risk an additional bone graft and/or bone morphogenetic protein-7 (BMP-7) were applied. Results. A successful consolidation of the nonunion was observed in 37 cases (80.4%) with a median healing time of six months (IQR 6). Younger patients showed significantly better consolidation. Four patients were lost to follow-up. Revision was necessary in a total of eight (16%) cases. In the initial treatment, intramedullary nailing was most common. . Discussion. The use of locking compression plates in combination with autologous cancellous bone graft has been shown to be a safe and effective treatment. In more complex cases, the use of the Masquelet technique and BMP-7 may be indicated at the first revision operation. Take home message: Our results suggest the Diamond Concept is a successful treatment strategy for nonunions of the humeral shaft. Cite this article: Bone Joint J 2016;98-B:81–7

Introduction and Objective. Digital infra-red thermography may have the capability of identifying local inflammations. Nevertheless, the role of thermography in diagnosing pin site infection has not been explored yet and the reliability and validity of this method for pin site surveillance is in question. The purpose of this study was to explore the capability and intra-rater reliability of thermography in detecting pin site infection. Materials and Methods. This explorative proof of concept study follows GRRAS -guidelines for reporting reliability and agreement studies. After clinical assessment of pin sites by one examiner using Modified Gordon Pin Infection Classification (Grade 0 – 6), thermographic images of the pin sites were captured with a FLIR C3 camera and analyzed by the FLIR tools software package. The maximum skin temperature around the pin site and the maximum temperature for the whole thermographic picture was measured. Intra-rater agreement was established and test-retests were performed with different camera angles. Results. Thirteen (4 females) patients (age 9–72 years) were included. Indications for frames: 4 fracture, 2 deformity correction, 1 lengthening, 6 bone transport. Days from surgery to thermography ranged from 27 to 385 days. Overall, 231 pin sites were included. Eleven pin sites were diagnosed with early signs of infection: five grade 1, five grade 2, one grade 3. Mean pin site temperature was 33.9 °C (29.0–35.4). With 34 °C as cut-off value for infection, sensitivity was 73%, specificity 67%, positive predictive value 10% and negative predictive value 98%. Intra-rater reliability for thermography was ICC 0.85 (0.77–0.92). The temperature measured was influenced by the camera postioning in relation to pin site with a variance of 0.2. Conclusions. Measurements of pin sites using the handheld FLIR C3 infrared camera was a reliable method and the temperature was related to infection grading. This study demonstrates that digital thermography with a handheld camera might be used for monitoring the pin sites after operations to detect early infection, however, future larger prospective studies are necessary

Adolescent idiopathic scoliosis (AIS) is a complex 3D deformity of the spine. Its prevalence is between 2% and 3% in the general population, with almost 10% of patients requiring some form of treatment and up to 0.1% undergoing surgery. The cosmetic aspect of the deformity is the biggest concern to the patient and is often accompanied by psychosocial distress. In addition, severe curves can cause cardiopulmonary distress. With proven benefits from surgery, the aims of treatment are to improve the cosmetic and functional outcomes. Obtaining correction in the coronal plane is not the only important endpoint anymore. With better understanding of spinal biomechanics and the long-term effects of multiplanar imbalance, we now know that sagittal balance is equally, if not more, important. Better correction of deformities has also been facilitated by an improvement in the design of implants and a better understanding of metallurgy. Understanding the unique character of each deformity is important. In addition, using the most appropriate implant and applying all the principles of correction in a bespoke manner is important to achieve optimum correction. In this article, we review the current concepts in AIS surgery. Cite this article: Bone Joint J 2018;100-B:415–24

Total hip replacement procedures are among the most frequent surgical interventions in all industrialized countries. Although it is a routine operationliterature reports that important parameters regarding for example cup orientation and leg length discrepancy often turn out to be not satisfying after surgery. This paper presents a novel concept to improve the reproducibility and accuracy for implantation of cup and stem prosthesis at exactly the desired locations. Existing computer- based commercial products either offer software solutions for just pre-operative planning, or imageless navigation systems that are only used during surgery in the operating theatre. The innovation of our approach is based on an integrated computer-assisted solution that combines pre-operative planning and intra-operative navigation to support THR procedures. The software for pre-operative planning can process both, 3D CT images and standard 2D x-ray images. A custom-built navigation system using optical 3D localizing technology has been developed to transfer planning results to the OR. The main objective of our approach is to implant the artificial joint in a way to restore the natural anatomy of the joint before surgery as close as possible, or with exactly planned modifications. In particular, cup inclination, cumulative anteversion of cup and stem, CCD angle and lateral offset, centre of rotation, leg length discrepancy, and joint range of motion are considered. It is not necessary to determine numerical values for all of these parameters because our approach uses a unique procedure to record the natural anatomical situation by combining pre-operative planning and intra-operative navigation, and subsequently supports implantation of the prosthesis components by surgical navigation in order to restore this situation. In case planar 2D x-ray images are used for pre-operative planning accurate scaling of these images is a prerequisite for exact determination of relevant parameters. The patient-specific scaling factor depends on the distance of the hip joint rotation centre from the x-ray detector or film. We have designed a low-cost localization system to be mounted close to the x-ray apparatus. It localizes the 3D position of the rotation centre by small motions of the leg and eliminates uncertainties of conventional methods that are caused by improper positioning of a calibration body. Easy and robust setup and application have been key objectives for the development of our custom-built navigation system. Acquisition of intraoperative parameters for example includes the determination of the acetabular centre axis by localizing selected landmarks at the acetabular rim. Intra-operative parameters are combined with pre-operative parameters without needing sophisticated matching procedures with the pre-operative images. A preliminary surgical workflow that will be detailed in the conference presentation has been designed for evaluation of the concept using sawbones models. Based on the promising results of our laboratory tests we have started to prepare first clinical experiments in close cooperation with surgeons

Objective. To investigate the effectiveness of applying fast track surgery concept in primary total hip arthroplasty. Methods. The data of patients with primary total hip arthroplasty in our department from January 1, 2013 to October 1, 2015 were retrospectively analyzed. The patients were divided into traditional recovery group, enhanced recoverygroup and update enhanced recovery group according to different interventions. The blood loss, transfusion rate, complications rate, postoperative function, length of stay, hospitalization expense and readmission rate were compared between three groups. Results. A total of 435 cases were included. Compared with traditional recovery group, the average blood loss, length of stay and total cases of complication in update enhanced recovery group were reduced 91.44 ml, 1.34 days and 14.05%, respectively, and the differences showed statistical significance. From 2013 to 2015 the hip flexion and abduction degree increased annually, the differences also showed statistical significance. The blood transfusion rate, other complications and hospitalization expense were all reduced, but there were no statistical significance. Conclusions. The emphasis of fast track surgery concept in primary total hip arthroplasty was the management in perioperative period. Through continuous optimization of intervention measures under the guidance of evidence based medicine, it can effectively accelerate recovery, diminish complications and reduce the length of hospital stay

Introduction. An increasing trend in the incidence of primary and revision bone replacements has been observed throughout the last decades, mainly among patients under 65 years old.10-year revision rates are estimated in the 5–20% range, mainly due to peri-implant bone loss. Recent advances allow the design of implants with custom-made geometries, nanometer-scale textured surfaces and multi-material structures. Technology also includes (bio)chemical modifications of the implants' surfaces. However, these approaches present significant drawbacks, as their therapeutic actuations are unable to: (1) perform long-term release of bioactive substances, namely after surgery; (2) deliver personalized stimuli to target bone regions and according to bone-implant integration states. The Innovative Concept. Here we propose the design of instrumented active implants with ability to deliver personalized biophysical stimuli, controlled by clinicians, to target regions in the bone-implant interface throughout the patients' lifetime. The idea is to design bone implants embedding actuators, osseointegration sensors, wireless communication and self-powering systems. This work proposes an advanced therapeutic actuator for personalized bone stimulation, and a self-powering system to electrically supply these advanced implants. Novel Capacitive Stimulators and Self-Powering Systems. A novel circular capacitive stimulator was designed for personalized stimulatory therapies based on the delivery of electric fields to bone cells. Its architecture is composed by 3 coplanar electrodes, 2 mm wide, 1 mm thick, and 0.5 mm apart from each other. It enables the delivery of controllable stimuli, as different stimuli (varying waveform, strength, frequency, etc.) can be delivered to target regions of bone. Numerical biophysical models were developed using COMSOL Multiphysics (v. 5.2) to analyze the osteogenic effects of stimulation delivered in vitro to MC3T3-E1 bone cells. 8 domains (electrodes, petri dish, substrate, air, cellular medium and physiological medium) were considered to simulate an apparatus to stimulate cell cultures. Simulations were carried out by applying low and high frequency (14 Hz and 60 kHz) sinusoidal excitations with 10 V of amplitude. A motion-driven and maintenance-free self-powering system was designed using magnetic levitation-based electromagnetic energy harvesting. A semi-analytical non-linear mathematical model of its complex energy transduction was developed (it includes modelling of the magnetic field produced by levitating hard magnetic elements, repulsive force between two magnets, electrical and mechanical damping, induced voltage, mechanical and electric dynamics) to estimate the energy harvested during gait patterns. Results. This cosurface stimulator is able to deliver similar magnitude stimuli to bone cells as those already recognized as osteogenic by previous studies. Heterogeneous stimuli is delivered both for low and high excitations, although quite different stimuli distributions are found along the cellular layer. Maximum stimuli occur over the electrode-anode region and its magnitude is approximately 0.3 V/mm. The electrode thickness influence must also be highlighted: the use of electrodes with 0.1 mm thick result in 2.5-fold magnitude increases in high-frequency stimulation. Excellent agreement was obtained between simulations and experiments with mean energy errors around 6% and cross-correlations higher than 85%. These results indicate that the design of this self-powering system can be optimized prior to fabrication and according to gait patterns of patients

Successful reconstruction of bone defects requires an adequate filling material that supports regeneration and formation of new bone within the treated defect in an optimal fashion. Currently available synthetic bone graft substitutes cannot fulfill all requirements of the highly complex biological processes involved in physiological bone healing. Due their unphysiologically asynchronous biodegradation properties, their specific foreign material-mediated side effects and complications and their relatively modest overall osteogenic potential, their overall clinical performance typically lags behind conventional bone grafts of human origin. However, defect- and pathology specific combination of synthetic bone graft substitutes exhibiting appropriate carrier properties with therapeutic agents and/or conventional bone graft materials allows creation of biologically enhanced composite constructs that can surpass the biological and therapeutic limits even of autologous bone grafts. This presentation introduces a bone defect reconstruction concept based on biological enhancement of optimal therapeutic agent-carrier composites and provides a rationale for an individual, requirement-specific adaptation of a truly patient-specific reconstruction of bone defects. It represents the pinnacle of the bone defect reconstruction pyramid, founded on the basic principles and prerequisites of complete elimination of the underlying pathology, preservation, augmentation or restoration of mechanical stability of the treated bone segment and creation of a biodegradable scaffold with adequate mechanical integrity. It summarises the current body of relevant experimental and clinical research, presents clinical case examples illustrating the various aspects of the proposed concept as well as early clinical results. The author hopes that the theoretical and conceptual framework provided, will help guide future research as well as clinical decision making with respect to this particular field