This study was proposed to evaluate the efficacy of fibrin clot augmentation in meniscal tear using inside-out meniscal repair. A total of 35 patients with meniscus tears were operated on with inside-out meniscus repair and fibrin clot augmentation. Patients were evaluated preoperatively and postoperatively with clinical criteria, Lysholm knee scoring system, and MRI. Out of the total 35 cases, 5 cases were lost to follow up. Clinical improvement was observed in 29 out of 30 patients (96.6%). The mean Lysholm score improved significantly from 67.63 ± 6.55 points preoperatively to 92.0 ± 2.9 points postoperatively (P < 0.05) in 2 years follow-up. Follow-up MRI in all patients revealed complete healing except in 1 case where the patient presented with recurrence of symptoms such as pain and locking which resolved with partial meniscectomy. Paraesthesia in the anterior part of the knee was observed in 2 cases. (6.6%). We conclude that fibrin clot augmentation is a good cost-effective modality of treatment for repairable meniscus tears to preserve the meniscus and decrease the point contact pressure on the condyles which may prevent the early occurrence of osteoarthritis

Rotator cuff repair has excellent clinical outcomes but continues to be a challenge when it comes to large and massive tears as well as revision procedures. Reported symptomatic retear rates are still too high to be acceptable. The purpose of the present study was to evaluate the effectiveness of a combination of augmentation techniques consisting of microfractures of the greater tuberosity, extracellular matrix (ECM) patch graft and subsequent platelet concentrate (PC) subacromial injections in revision rotator cuff repair. The study was designed as a retrospective comparative study on prospectively collected data from a consecutive cohort of patients. All patients who underwent arthroscopic revision rotator cuff repair for symptomatic failure of previous posterosuperior rotator cuff repair were considered eligible for the study. Symptomatic failure had been diagnosed according to clinical examination and confirmed by magnetic resonance imaging (MRI). Structural integrity had been assessed on MRI and classified according to Sugaya classification. Only patients affected by stage IV-V were considered eligible. Tear reparability was confirmed during arthroscopy. Only patients with a minimum 2 years follow-up were included. Patients were divided in two groups. In group 1 (control group) a standard arthroscopic revision and microfractures of the greater tuberosity were performed; in group 2 (experimental group), microfractures of the greater tuberosity and a ECM patch graft were used to enhance tendon repair, followed by postoperative PC injections. Minimum follow-up was 12 months. Primary outcome was the Constant-Murley score (CMS) normalized for age and gender. Subjective outcome was assessed with the Disabilities of the Arm, Shoulder and Hand (DASH) score in its short version (Quick-DASH). Tendon integrity was assessed with MRI at 6 months after surgery. Comparison between groups for all discrete variables at baseline and at follow-up was carried out with the Student's t-test for normally distributed data, otherwise Mann-Whitney U-test was used. Within-group differences (baseline vs follow-up) for discrete variables were analyzed by paired t-test, or by Wilcoxon signed-rank test in case of data with non-normal distribution. Differences for categorical variables were assessed by chi-squared test. Significance was considered for p values < 0.05. Forty patients were included in the study (20 patients for each group). The mean follow-up was 13 ± 1.6 months. No patients were lost at the follow up. Comparison between groups did not show significant differences for baseline characteristics. At follow-up, mean CMS was 80.7 ± 16.6 points in group 1 and 91.5 ± 11.5 points in group 2 (p= 0.022). Mean DASH score was 28.6 ± 21.6 points in group 1 and 20.1 ± 17.4 points in group 2 (p= 0.178). Post-operative MRI showed 6 healed shoulders in Group 1 and 16 healed shoulders in Group 2 (p<0.004). No postoperative complications were reported in both groups. The combination of microfractures of the greater tuberosity, ECM patch graft, and subsequent PC subacromial injections is an effective strategy in improving tendon healing rate

Background. Osteoporotic fracture fixation in the proximal humerus remains a critical challenge. While the biomechanical benefits of screw augmentation with bone cement are established, minimising the cement volume may help control any risk of extravasation and reduce surgical procedure time. Previous experimental studies suggest that it may be sufficient to only augment the screws at the sites of the lowest bone quality. However, adequately testing this hypothesis in vitro is not feasible. Methods. This study systematically evaluated the 64 possible strategies for augmenting six screws in the humeral head through finite element simulations to determine the relative biomechanical benefits of each augmentation strategy. Two subjects with varying levels of local bone mineral density were each modeled with a 2-part and 3-part fracture that was stabilised with a PHILOS plate. The biomechanical fixation was evaluated under physiological loads (muscle and joint reaction forces) that correspond to three different motions: 45 degrees abduction, 45 degrees abduction with 45 degrees internal rotation, and 45 degrees flexion. Results. The higher risk cases (low bone quality or 3-part fracture) exhibited greater peri-implant bone strains and derived greater benefits from screw augmentation. When selecting four screws to augment, the biomechanical benefits ranged from a 25% reduction in bone strain to a 59% reduction in bone strain, depending on the choice of screws. Further, the relative benefits of each augmentation strategy varied between patients and under different loading conditions. Correlations between local bone mineral density and benefits of augmentation were not significant. Conclusions. An optimal augmentation strategy is likely patient-specific and a larger cohort, modeled under a variety of conditions, would be required to elucidate any patient-specific factors (e.g. morphology or bone quality) that may dictate the relative benefits of each augmentation strategy

Intervertebral disc (IVD) degeneration is one of the major causes of back pain. A number of emerging treatments for the condition have failed during clinical trial due to the lack of robust biomechanical testing during product development. The aim of this work was to develop improved in-vitro testing methods to enable new therapeutic approaches to be examined pre-clinically. It forms part of a wider programme of research to develop a minimally invasive nucleus augmentation procedure using self-assembling hydrogels. Previous static testing on extracted IVDs have shown large inter-specimen variation in the measured stiffness when specimen hydration and fluid flow were not well controlled. In this work, a method of normalising the hydration state of IVDs prior-to and during compressive testing was developed. Excised adult bovine IVDs underwent water-pik treatment and a 24-hour agitated bath in monosodium citrate solution to maximise fluid mobility. Specimens were submerged in a saline bath and held under constant pressure for 24 hours, after which the rate of change of displacement was low. Specimens were then cyclically loaded, from which the normalised specimen stiffness was determined. A degenerate disc model was developed with the use of enzymatic degeneration, allowing specimens to be tested sequentially in a healthy, degenerate, and then treated state. Self-assembling peptide-GAG hydrogels were tested using the developed method and the effect of treatment on stiffness and disc height were assessed. Compared to previous static tests, the improved method reduced the variation in the normalised specimen stiffness. In addition, statistically significant differences were seen before and after enzymatic degradation to simulate degeneration, thus providing controls against which to evaluate treatments. The augmentation of the nucleus with the hydrogel intervention reduces the stiffness of the degenerate disc towards that of the healthy disc. This method is now being used to further investigate nucleus augmentation devices

Abstract. Objectives. Develop a methodology to assess the long term mechanical behavior of intervertebral discs by utilizing novel sequential state testing. Methods. Bovine functional spinal units were sequentially mechanically tested in (1) native (n=8), (2) degenerated (n=4), and (3) treated states (n=4). At stage (2), artificial degeneration was created using rapid enzymatic degeneration, followed by a 24 hour hold period under static load at 42°C. At stage (3), nucleus augmentation treatments were injected with a hydrogel or a ‘sham’ (water, chondroitin sulfate) injection. The mechanical protocol employed applied a static load hold period followed by cyclic compressive loading between ∼350 and 750 N at 1 Hz. 1000 cycles were applied at each stage, and the final test on each specimen was extended up to 20000 cycles. To verify if test time can be reduced, functions were fitted using stiffness data up to 100, 1000, 2500, 5000, 10000 and 20000 cycles. Linear regression for the native specimens comparing the stiffness at various cycles to the stiffness at 20000 cycles was completed. Results. Independent of the disc state, as the number of cycles increased, the hysteresis decreased and the stiffness increased. The degenerated specimen stiffness was greater than the healthy and treated stiffness and the degenerate hysteresis loops were smaller. A mathematical model was found to successfully predict the high cycle behaviour of the disc reaching a root mean squared (RMS) error below 10% when using 5000 or more cycles. The linear regression gave a RMS error below 7.5% at 1000 cycles. Conclusions. A method was developed to consistently determine intervertebral disc mechanics through sequential testing. A shortened cyclic testing period was shown to be viable as a method to reduce preliminary test time for novel hydrogels, compared to currently literature. The methodology permits rapid preliminary assessment of intervertebral disc mechanics and treatments. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

We used an in vivo model to assess the use of an autogenous cancellous bone block and marrow graft for augmenting tendon reattachment to metallic implants. We hypothesised that augmentation of the tendon-implant interface with a bone block would enable retention of the graft on the implant surface, enhance biological integration, and result in more consistent functional outcomes compared with previously reported morcellised graft augmentation techniques. A significant improvement in functional weight-bearing was observed between six and 12 weeks. The significant increase in ground reaction force through the operated limb between six and 12 weeks was greater than that reported previously with morcellised graft augmented reconstructions. Histological appearance and collagen fibre orientation with bone block augmentation more closely resembled that of an intact enthesis compared with the morcellised grafting technique. Bone block augmentation of tendon-implant interfaces results in more reliable functional and histological outcomes, with a return to pre-operative levels of weight-bearing by 24 weeks

Background. Bone is a hierarchically structured hard tissue that consists of approximately 70 wt% low-crystallinity hydroxyapatite. Intricate tubular channels, such as Haversian canals, Volkman's canals, and canaliculi are a preserved feature of bone microstructure. These structures provide pathways for vasculature and facilitate cell-to-cell communication processes, together supporting viability of cellular components and aiding in remodeling processes. Unfortunately, many commercial bone augmentation materials consist of highly crystalline phases that are absent of the structuring present within the native tissue they are replacing. This work reports on a the development of a novel bone augmentation material that is able to generate biologically analogous tubular calcium phosphate mineral structures from hydrogel-based spheres that can be packed into defects similar to those encountered in vivo. Experimental. Calcium loaded spheres were made by adding 5 wt% agar powder to 1 M calcium nitrate solutions, before heating the mixture to 80–90 oC and feeding droplets of gel into a reservoir of liquid nitrogen. Deposition of tubular mineral was initiated by exposure to ammonium phosphate solutions at concentrations between 500 mM and 1 M, and was characterized by micro-XRF mapping, XRD and SEM techniques. For an ex vivo model, human bone tissue was collected from patients undergoing elective knee replacement surgery. The United Kingdom National Research Ethics Service (East of Scotland Research Ethics Service) provided ethical approval (11/ES/1044). The augmented defect of the model was characterised by micro-XRF mapping and micro-CT techniques. Results and Discussion. Immersion of calcium-loaded hydrogel spheres in physiological solutions rich in phosphate promotes the release of calcium rich streams from the sphere surface, resulting in the precipitation of tubule structures. Micro-XRF mapping, XRD and SEM, revealed tubules possessed hierarchically structuring and consisted of low-crystallinity hydroxyapatite, making them analogous in composition and structure to incritate features of bone microstructure. When brought into close proximity with one another, spheres become fused in a matter of minutes by the entanglement and subsequent interstitial mineralisation of the mineral tubules. Micro-XRF mapping and micro-CT analysis of an augmented ex vivo human tissue defect model demonstrated the extensive deposition of low-crystallinity tubular mineral throughout a tissue defect. Conclusions. This is possibly the first example of a bone augmentation material that is able to generate biologically analogous structures in situ, and therefore may serve as a better scaffold for bone formation over synthetic alternatives. Moreover, the formation of structured mineral aids in achieving rapid hardening of the augmenting calcium-loaded hydrogel shperes within the defect space

When performing total hip replacements in patients with hip dysplasia, acetabular augmentation may be required to prevent early component failure. Preoperative radiographic templating may help estimate acetabularcomponent coverage but has not previously been shown to predict the need for augmentation. We developed a simple method to estimate the percentage of acetabular component coverage from pre-operative radiographs (True: False cup ratio). We aimed to evaluate whether this couldpredict the need foracetabular augmentation at primary total hip replacement for patients with dysplastic hips. We reviewed all patients with hip dysplasia who underwent a primary total hip replacement from 2005–2012. Classification of hip dysplasia (Crowe), centre edge angle (CEA), Sharp and Tonnis angles were determined on pre-operative radiographs for each patient. Templating was performed on anteroposteriorand lateral view hip radiographs to determine the likely percentage of acetabular component coverage using the True: False cup ratio. Patients requiring acetabular augmentation at time of primary total hip arthroplasty were noted. 128 cases were reviewed, 31 (24%) required acetabularaugmentation. Comparison between augmented and non-augmented cases revealed no difference in the mean CEA (p = 0.19), Sharp angles (p = 0.76) or Tonnis angles (p = 0.32). A lower True Cup: False Cup ratio was observed in the augmented groupcompared to the non-augmented group(median = 0.68 vs 0.88, p < 0.01). Preoperative templating can help predict which dysplastic hips are likely to require acetabular augmentation at primary total hip replacement

The high risk and the associated high mortality of secondary, contralateral hip fractures [1,2] could justify internal, invasive prophylactic reinforcement of the osteoporotic proximal femur to avoid these injuries in case of a low energy fall. Previous studies have demonstrated high potential of augmentation approaches [3,4,5], but to date there has no ideal solution been found. The development of optimized reinforcement strategies can be aided with validated computer simulation tools that can be used to evaluate new ideas. A validated non-linear finite element (FE) simulation tool was used here to predict the yield and fracture load of twelve osteoporotic or osteopenic proximal femora in sideways fall based on high resolution CT images. Various augmentation strategies using bone cement or novel metal implants were developed, optimized and virtually performed on the bone models. The relative strengthening compared to the non-augmented state was evaluated using case-specific FE analyses. Strengthening effect of the cement-based augmentation was linearly proportional to cement volume and was significantly affected by cement location. With the clinically acceptable 12.6 ± 1.2 ml volume and optimized location of the cement cloud, compared to the non-augmented state, 71 ± 26% (42 – 134%) and 217 ± 166% (83 – 509%) increase in yield force and energy was reached, respectively. These were significantly higher than previously published experimental results using the “central” cement location [5], which could be well predicted by our FE models. The optimized metal implant could provide even higher strengthening effect: 140 ± 39% (76 – 194%) increase in yield force and +357 ± 177% (132 – 691%) increase in yield energy. However, for metal implants, a higher risk of subcapital fractures was indicated. For both cement and metal, the originally weaker bones were strengthened exponentially more compared to the stronger ones. The ideal solution for prophylactic augmentation should provide an appropriate balance between the requirements of being clinically feasible, ethically acceptable and mechanically sufficient. Even with the optimized location, the cement-based approach may not provide enough strengthening effect and adequate reproducibility of the identified optimal cement cloud position may not be achieved clinically. While the metal implant based strategy appears to be able to deliver the required strengthening effect, the ethical acceptance of this more invasive option is questionable. Further development is therefore required to identify the ideal, clinically relevant augmentation strategy. This may involve new cement materials, less invasive metal implants, or a combination of both. The FE simulation approach presented here could help to screen the potential ideas and highlight promising candidates for experimental evaluation

Prophylactic augmentation is meant to reinforce the vertebral body (VB), but in some cases it is suspected to actually weaken it. To elucidate the biomechanical efficacy of prophylactic augmentation, the full-field three-dimensional strain distributions were measured for the first time inside prophylactic-augmented vertebrae. Twelve thoracic porcine vertebrae were assigned to three groups: 4 were augmented with bone cement for vertebroplasty (Mendec-Spine, Tecres), 4 were treated with another bone cement for vertebroplasty (Calcemex-Spine, Tecres) while the other 4 were tested untreated as a control. Destructive tests were carried out under axial compression, in a step-wise fashion (unloaded, 5%, 10% and 15% compression). At each loading step, μCT-images were acquired. The internal strain distribution was investigated by means of DVC analysis. Some augmented specimens were stronger than the respective control, while others were weaker. In most of the specimens, the strain distribution in the elastic regime (5% compression) seemed to predict the location of the micro-damage initiation before it actually became identifiable (at 10% and 15% compression). The measured strain had the same order of magnitude for all groups. However, in the control vertebrae, the highest strain would unpredictably appear at any location inside the VB. Conversely, for both augmentation groups, the highest strains were measured in the regions adjacent to the injected cement mass, whereas the cement-interdigitated-bone was less strained. Localization of high strains and failure was consistent between specimens, but different between the two cement types: with Mendec-Spine failure the highest strains were mainly localized at mid-height and at the same level where the cement mass was localized; with Calcemex-Spine failure the highest strains were mainly cranial and caudal to the cement mass. Both the micro-CT images, and the DVC strain analysis highlighted that:. The cement mass was less strained than any other regions in the vertebra. Failure never started inside the cement mass. This can be explained with the additional stiffening and reinforcement associated with the infiltration of the cement inside the trabecular bone. The highest strains and failure were localized in the bone adjacent to the cement-bone interdigitated region. This can be explained by the strain concentration between the cement-interdigitated bone (stiffer and stronger), and the adjacent non-augmented trabecular bone. The strain maps in the elastic regime and the localization of failure was different in the augmented vertebrae, when compared to the natural controls. This suggests an alteration of the load sharing in the augmented structure where the load is mostly carried by the cement region. The different localization of failure initiation between the two augmented groups could be explained by the different mechanical properties of the two cements. This study has demonstrated the potential of DVC in measuring the internal strain and failure in prophylactic-augmented vertebrae. It has been shown that failure starts inside the augmented VB, next to the injected cement mass. This can help establishing better criteria (in terms of localization of the cement mass) in order to improve clinical protocols for vertebroplasty surgical procedures

The treatment of massive chronic tears is problematic. The re-tear rate following surgery for extensive cuff tears remains high, and there is little consensus regarding optimum treatment. To investigate the outcome of a cohort of patients who had open repair of an extensive cuff tear using the Leeds Kuff patch as an augment. A retrospective cohort study of consecutive patients with a massive cuff tear who had surgery in our regional elective orthopaedic centre over a two year period from January 2015 to Dec 2016. All patients followed identical rehabilitation protocols, supervised by physiotherapists with an interest in the shoulder. Outcomes assessment was undertaken at a minimum of 12 months by a registrar or physiotherapist who was not part of the treating team. Pre-op data collection included; range of motion, pain score, Oxford shoulder score (OSS), assessment of muscle atrophy on MRI. Data collection was completed in 15 patients. The mean age was 62 yrs (56 – 75). The mean pre-op OSS was 22, improving to a mean of 43. The range of motion and pain score improved. There were no intra-operative complications. One patient required a second surgery for evacuation of a haematoma at 10 days post op. One patient had an obvious re-tear at 4 months. Open rotator cuff repair with synthetic Kuff patch augmentation for chronic degenerative tears appears worthwhile when assessed at 12 months and they continuous to improve even at 18 months. This treatment method may be a useful option for patients > 70 years old

The purpose of this study was to develop a novel, minimally invasive therapy for nucleus pulposus augmentation without the need for major surgical incision. Two optimum patented self-assembling peptides based on natural amino acids were mixed with glycosaminoglycans (GAGs) to form reversible, tunable hydrogels that mimic the vital biological osmotic pumping action and aid in swelling pressure of the intervertebral disc (IVD). Separate peptide and GAG solutions can be switched from fluid to gel upon mixing inside the body. The gels were analysed using a series of complementary techniques (FTIR, TEM & rheometry) to determine their cross-length scale structure and properties. Approaches to developing a clinical product were then developed including the incorporation of a fluorescent probe and a CT contrast agents to aid visualization of the gels, and a semi-automatic syringe driver rig, incorporating a pressure sensor, for the delivery of the solutions into the intervertebral discs. The efficacy of the procedure in restoring disc height and biomechanics was examined using chemically degenerated bovine caudal samples. It was found the presence of the GAGs stabilized the peptides forming stiffer gels, even upon injection through a long (∼10cm) small gauge needle. The injected gels were easily visualized post injection by microCT and by eye during dissection under visible and UV light. It was also noted that following injection, the disc height of the degenerated samples was restored to a similar level of that observed for native discs. A hydrogel has been developed that is injected through a narrow bore needle using a semi-automatic delivery rig and forms a self-assembled gel in situ which has shown to restore the disc height. Further tests are now underway to examine their biomechanical performance across more physiological time periods

The healing of a hamstring graft to bone is the weak link in the reconstruction of a cruciate ligament using this donor material. We therefore investigated the augmentation of healing at the tendon-bone interface using calcium-phosphate cement (CPC). We performed semitendinosus autograft reconstructions of the anterior cruciate ligament on both knees of 22 New Zealand white rabbits. The interface between the grafted tendon and the bone tunnel for one knee was filled with CPC. Six rabbits were killed at the end of the first and second post-operative weeks in order to evaluate the biomechanical changes. Two rabbits were then killed sequentially at the end of weeks 1, 3, 6, 12 and 24 after operation and tissue removed for serial histological observation. Histological examination showed that the use of CPC produced early, diffuse and massive bone ingrowth. By contrast, in the non-CPC group of rabbits only a thin layer of new bone was seen. Mechanical pull-out testing at one week showed that the mean maximal tensile strength was 6.505 ± 1.333 N for the CPC group and 2.048 ± 0.950 N for the non-CPC group. At two weeks the values were 11.491 ± 2.865 N and 5.452 ± 3.955 N, respectively. Our findings indicate that CPC is a potentially promising material in clinical practice as regards its ability to reinforce the fixation of the tendon attachment to bone and to augment the overall effectiveness of tendon healing to bone

Femoroplasty is the process of injecting cement (cement augmentation) into the proximal femur to prevent osteoporotic hip fractures. Femoroplasty increases the strength and energy to failure of the femur and can be performed in a minimally-invasively manner with lower hospitalization costs and reduced recovery. Our hypothesis was that efficient cement augmentation strategies can be identified via computational optimization. Therefore, using patient-specific planning we can minimize cement volume while increasing bone strength and reducing the risk of fracture. We proposed an in-silico methodology that was validated with in vitro experiments. A discrete particle model for cement infiltration was used to determine the optimum volume and filling pattern of the cement such that the best outcome was achieved. Several artificial bones were scanned before and after cement augmentation to applied previous in silico methodology. Then those femurs were mechanically tested (non-augmented and augmented). Therefore, in silico methodology was validated. Cement augmentation significantly increased the yield load. Predicted yield loads correlated well with the experiments. Results suggest that patient-specific planning of femoroplasty reduces the risk of hip fracture while minimizing the amount of cement required.

Infection of orthopaedic implants is a significant problem, with increased antibiotic resistance of adherent ‘biofilm’ bacteria causing difficulties in treatment. We have investigated the in vitro effect of a pulsed electromagnetic field (PEMF) on the efficacy of antibiotics in the treatment of infection of implants.

Five-day biofilms of Staphylococcus epidermidis were grown on the tips of stainless-steel pegs. They were exposed for 12 hours to varying concentrations of gentamicin or vancomycin in microtitre trays at 37°C and 5% CO₂. The test group were exposed to a PEMF. The control tray was not exposed to a PEMF. After exposure to antibiotic the pegs were incubated overnight, before standard plating onto blood agar for colony counting.

Exposure to a PEMF increased the effectiveness of gentamicin against the five-day biofilms of Staphylococcus epidermidis. In three of five experiments there was reduction of at least 50% in the minimum biofilm inhibitory concentration. In a fourth experiment there was a two-log difference in colony count at 160 mg/l of gentamicin. Analysis of variance (ANOVA) confirmed an effect by a PEMF on the efficacy of gentamicin which was significant at p < 0.05. There was no significant effect with vancomycin.

A number of techniques have been developed to improve the immediate mechanical anchorage of implants for enhancing implant longevity. This issue becomes even more relevant in patients with osteoporosis who have fragile bone. We have previously shown that a dynamic hip screw (DHS) can be augmented with a calcium sulphate/hydroxyapatite (CaS/HA) based injectable biomaterial to increase the immediate mechanical anchorage of the DHS system to saw bones with a 400% increase in peak extraction force compared to un-augmented DHS. The results were also at par with bone cement (PMMA). The aim of this study was to investigate the effect of CaS/HA augmentation on the integration of a different fracture fixation device (gamma nail lag-screw) with osteoporotic saw bones. Osteoporotic saw bones (bone volume fraction = 15%) were instrumented with a gamma nail without augmentation (n=8) or augmented (n=8) with a CaS/HA biomaterial (Cerament BVF, Bonesupport AB, Sweden) using a newly developed augmentation method described earlier. The lag-screws from both groups were then pulled out at a displacement rate of 0.5 mm/s until failure. Peak extraction force was recorded for each specimen along with photographs of the screws post-extraction. A non-parametric t-test was used to compare the two groups. CaS/HA augmentation of the lag-screw led to a 650% increase in the peak extraction force compared with the controls (p<0.01). Photographs of the augmented samples shows failure of the saw-bones further away from the implant-bone interface indicating a protective effect of the CaS/HA material. We present a novel method to enhance the immediate mechanical anchorage of a lag-screw to osteoporotic bone and it is also envisaged that CaS/HA augmentation combined with systemic bisphosphonate treatment can lead to new bone formation and aid in the reduction of implant failures and re-operations

Majority of osteoporosis related fractures are treated surgically using metallic fixation devices. Anchorage of fixation devices is sometimes challenging due to poor osteoporotic bone quality that can lead to failure of the fracture fixation. Using a rat osteoporosis model, we employed neutron tomography and histology to study the biological effects of implant augmentation using an isothermally setting calcium sulphate/hydroxyapatite (CaS/HA) biomaterial with synthetic HA particles as recruiting moiety for systemically administered bisphosphonates. Using an osteoporotic sawbones model, we then provide a standardized method for the delivery of the CaS/HA biomaterial at the bone-implant interface for improved mechanical anchorage of a lag-screw commonly used for hip fracture fixation. As a proof-of-concept, the method was then verified in donated femoral heads and in patients with osteoporosis undergoing hip fracture fixation. We show that placing HA particles around a stainless-steel screw in-vivo, systemically administered bisphosphonates could be targeted towards the implant, yielding significantly higher peri-implant bone formation compared to un-augmented controls. In the sawbones model, CaS/HA based lag-screw augmentation led to significant increase (up to 4 times) in peak extraction force with CaS/HA performing at par with PMMA. Micro-CT imaging of the CaS/HA augmented lag-screws in cadaver femoral heads verified that the entire length of the lag-screw threads and the surrounding bone was covered with the CaS/HA material. X-ray images from fracture fixation surgery indicated that the CaS/HA material could be applied at the lag-screw-bone interface without exerting any additional pressure or risk of venous vascular leakage.: We present a new method for augmentation of lag-screws in fragile bone. It is envisaged that this methodcould potentially reduce the risk of fracture fixation failure especially when HA seeking “bone active” drugs are used systemically

The most important outcome predictor of Legg-Calvé-Perthes disease (LCPD) is the shape of the healed femoral head. However, the deformity of the femoral head is currently evaluated by non-reproducible, categorical, and qualitative classifications. In this regard, recent advances in computer vision might provide the opportunity to automatically detect and delineate the outlines of bone in radiographic images for calculating a continuous measure of femoral head deformity. This study aimed to construct a pipeline for accurately detecting and delineating the proximal femur in radiographs of LCPD patients employing existing algorithms. To detect the proximal femur, the pretrained stateof-the-art object detection model, YOLOv5, was trained on 1580 manually annotated radiographs, validated on 338 radiographs, and tested on 338 radiographs. Additionally, 200 radiographs of shoulders and chests were added to the dataset to make the model more robust to false positives and increase generalizability. The convolutional neural network architecture, U-Net, was then employed to segment the detected proximal femur. The network was trained on 80 manually annotated radiographs using real-time data augmentation to increase the number of training images and enhance the generalizability of the segmentation model. The network was validated on 60 radiographs and tested on 60 radiographs. The object detection model achieved a mean Average Precision (mAP) of 0.998 using an Intersection over Union (IoU) threshold of 0.5, and a mAP of 0.712 over IoU thresholds of 0.5 to 0.95 on the test set. The segmentation model achieved an accuracy score of 0.912, a Dice Coefficient of 0.937, and a binary IoU score of 0.854 on the test set. The proposed fully automatic proximal femur detection and segmentation system provides a promising method for accurately detecting and delineating the proximal femoral bone contour in radiographic images, which is necessary for further image analysis

Tendons mainly consist of collagen in order to withstand high tensile forces. Compared to other, high turnover tissues, cellularity and vascularity in tendons are low. Thus, the natural healing process of tendons takes long and can be problematic. In case of injury to the enthesis, the special transition from tendon over cartilage to bone is replaced by a fibrous scar tissue, which remains an unsolved problem in rotator cuff repair. To improve tendon healing, many different approaches have been described using scaffolds, stem cells, cytokines, blood products, gene therapy and others. Despite promising in vitro and in vivo results, translation to patient care is challenging. In clinics however, tendon auto- or allografts remain still first choice to augment tendon healing if needed. Therefore, it is important to understand natural tendon properties and natural tendon healing first. Like in other tissues, senescence of tenocytes seems to play an important role for tendon degeneration which is interestingly not age depended. Our in vivo healing studies have shown improved and accelerated healing by adding collagen type I, which is now used in clinics, for example for augmentation of rotator cuff repair. Certain cytokines, cells and scaffolds may further improve tendon healing but are not yet used routinely, mainly due to missing clinical data, regulatory issues and costs. In conclusion, the correct diagnosis and correct first line treatment of tendon injuries are important to avoid the necessity to biologically augment tendon healing. However, strategies to improve and accelerate tendon healing are still desirable. New treatment opportunities may arise with further advances in tendon engineering in the future

The Spine Surgery Unit of IRCCS Istituto Ortopedico Rizzoli is dedicated to the diagnosis and the treatment of vertebral pathologies of oncologic, degenerative, and post-traumatic origin. To achieve increasingly challenging goals, research has represented a further strength for Spinal Surgery Unit for several years. Thanks to the close synergy with the Complex Structure Surgical Sciences and Technologies, IRCCS Istituto Ortopedico Rizzoli, extensive research was carried out. The addition of the research activities intensifies a complementary focus and provides a unique opportunity of innovation. The overall goal of spine research for the Spine Surgery Unit and for the Complex Structure Surgical Sciences and Technologies is and has been to:. - investigate the factors that influence normal spine function;. - engineer and validate new and advanced strategies for improving segmental spinal instrumentation, fusion augmentation and grafting;. - develop and characterize advanced and alternative preclinical models of vertebral bone metastasis to test drugs and innovative strategies, taking into account patient individual characteristics and specific tumour subtypes so predicting patient specific responses;. - evaluate the clinical characteristics, treatment modalities, and potential contributing and prognostic factors in patients with vertebral bone metastases;. - realize customized prosthesis to replace vertebral bodies affected by tumours or major traumatic events, specifically engineered to reduce infections, and increase patients’ surgical options. These efforts have made possible to obtain important results that favour the translation of basic research to application at the patient's bedside, and from here to routine clinical practice (without excluding the opposite pathway, in which the evidence generated by clinical practice helps to guide research). Although translational research can provide patients with valuable therapeutic resources, it is not risk-free. Thus, it is therefore necessary an always close collaboration between researchers and clinicians in order to guarantee the ethicality of translational research, by promoting the good of individuals and minimising the risks