Aims. Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are common orthopaedic procedures requiring postoperative radiographs to confirm implant positioning and identify complications. Artificial intelligence (AI)-based image analysis has the potential to automate this postoperative surveillance. The aim of this study was to prepare a scoping review to investigate how AI is being used in the analysis of radiographs following THA and TKA, and how accurate these tools are. Methods. The Embase, MEDLINE, and PubMed libraries were systematically searched to identify relevant articles. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews and Arksey and O’Malley framework were followed. Study quality was assessed using a modified Methodological Index for Non-Randomized Studies tool. AI performance was reported using either the area under the curve (AUC) or accuracy. Results. Of the 455 studies identified, only 12 were suitable for inclusion. Nine reported implant identification and three described predicting risk of implant failure. Of the 12, three studies compared AI performance with orthopaedic surgeons. AI-based implant identification achieved AUC 0.992 to 1, and most algorithms reported an accuracy > 90%, using 550 to 320,000 training radiographs. AI prediction of dislocation risk post-THA, determined after five-year follow-up, was satisfactory (AUC 76.67; 8,500 training radiographs). Diagnosis of hip implant loosening was good (accuracy 88.3%; 420 training radiographs) and measurement of postoperative acetabular angles was comparable to humans (mean absolute difference 1.35° to 1.39°). However, 11 of the 12 studies had several methodological limitations introducing a high risk of bias. None of the studies were externally validated. Conclusion. These studies show that AI is promising. While it already has the ability to analyze images with significant precision, there is currently insufficient high-level evidence to support its widespread clinical use. Further research to design robust studies that follow standard reporting guidelines should be encouraged to develop AI models that could be easily translated into real-world conditions. Cite this article: Bone Joint J 2022;104-B(8):929–937

Introduction: Dual Energy x-ray absorptiometery (DXA) is a useful tool for the assessment of peri-prosthetic bone mineral changes following total joint replacement. In order to assess these changes the precision of the DXA technique must be optimised. While patient positioning is an important factor, the role of the analysis software should also be considered. We developed and applied a new image analysis method to data from the EXPERT-XL fan beam densitometer (LUNAR GE, USA) aiming to improve reproducibility of bone region and tissue type determination by the analysis software. Methods: 60 patients with cemented THR received repeat same day DXA examinations. These were initially analysed strictly according to the manufacturer’s femoral peri-prosthetic protocol. A modification of this protocol was attempted allowing further small corrections to the tissue typing by the operator. The scans were then reanalysed using locally developed image analysis to accurately determine the bone, prosthesis and Gruen zone boundaries. The coefficient of variation (CV) was calculated from the differences of the repeat examinations for each of the seven Gruen zones and for the whole peri-prosthetic region. Results: The average zone CV was 5%. The poorest was zone 1 (10%) and best zone 4 (2%). With the operator corrections there was an overall 4% improvement. With our method there was an overall 40% reduction in variation (average CV 3%, maximum 4%, minimum 2%). The whole region CV was 3.1% for the standard method 2.7% modified and 1.3% for our method. Discussion: Our method significantly improved the reproducibility of EXPERT analysis. This study demonstrates the high dependency of DXA precision on robust regional analysis

Background. Following an anterior cruciate ligament (ACL) injury, the affected knee is known to experience bone loss and is at significant risk of becoming osteoporotic. Surgical reconstruction is performed to attempt to restore the function of the knee and theoretically restore this bone density loss. Cross-sectional analysis of the proximal tibia using peripheral quantitative computed tomography (pQCT) enables localised analysis of bone mineral density (BMD) changes. The aim of this study was to establish the pattern of bone density changes in the tibia pre- and post- ACL reconstruction using pQCT image analysis. Methods. Eight patients who underwent ACL reconstruction were included. A cross sectional analysis of the proximal tibia was performed using a pQCT scanner pre-operatively and one to two years post-operatively on both the injured and contralateral (control) knee. The proximal two and three percent slices [S2 and S3] along the tibia were acquired. These were exported to Matlab(tm) and automated segmentation was performed to remove the tibia from its surrounding structures. Cross correlation was applied to co-register pairs of images and patterns of change in BMD were mapped using a t-test (p<0.05). Connected components of pixels with significant change in BMD were created and used to assess the impact of ACL injury & reconstruction on the proximal tibial BMD. Results. Prior to surgical ACL reconstruction, the BMD in the injured leg was significantly reduced relative to the control leg [S2: p=0.002, S3: p=0.002]. Post surgery, the proximal tibial BMD did not change in either leg [Control S2: p=0.102, S3: p=0.181; Injured S2: p=0.093, S3: p=0.439]. The post surgical images demonstrated patterns of increasing BMD surrounding the tunnel in the form of compact bone. Discussion. A significant reduction in proximal tibial BMD was observed in the ACL injured legs relative to control legs. The pattern of pre-operative bone loss was generally observed to be global across the entire slice. No change in BMD was observed following ACL reconstruction, in either injured or control leg. These results indicate that proximal tibial BMD is reduced and does not change after ACL reconstruction

The purpose of this study was to determine the normal angle of rotation of the axis of each finger using digital image analysis, whether the rotation of the digits is symmetrical in the two hands of an individual, and the reliability of this method. Standardised digital photographic images were taken of thirty healthy volunteers. The palm of each hand was placed on a flat bench top with their fingers held in extension and adducted, to give an end-on image of all four fingers. Three independent observers analysed the images using Adobe Photoshop software. The rotational angle of each finger was defined as the angle created by a straight line connecting the radial and ulnar border of the nail plate and the bench top horizon. The three observers showed Inter-Rater Reliability of 92%. The mean angles of rotation were: Index 13°, Middle 10°, Ring 5°, Little 12°. The differences in angle of rotation of the index and middle finger between the left and right hand were statistically significant (p=0.003, and p=0.002 respectively), demonstrating asymmetry between the two sides. The differences in angle of rotation of the ring and little finger of the left and right hand were not significantly significant (p= 0.312 and p=0.716 respectively). In conclusion, symmetry was seen in the little and ring but not in the index and middle fingers. Digital image analysis provides a non-invasive and reproducible method of quantifying the rotation of normal fingers and may be of use as a diagnostic tool in the assessment and management of hand injuries

A computer-based image analysis system has been developed as a research tool in total hip replacement. The system has been programmed to take multiple measurements from coronal plane radiographs. Poor quality radiographic images can be enhanced and standardised. The measurements which can be obtained include stem subsidence, cup migration, cup wear, and stem loosening. Reproducibility and accuracy were +/- 0.01 mm and +/- 0.5 mm respectively. The present application is in retrospective research, but prospective monitoring of radiographs is planned

Introduction. Currently, a validate scale of ankle osteoarthritis (OA) is not available and different classifications have been used, making comparisons between studies difficult. In other joints as the hip and knee, the Kellgren-Lawrence (K&L) scale, chosen as reference by the World Health Organizations is widely used to characterize OA. It consists of a physician based assessment of 3 radiological features: osteophyte formation, joint space narrowing and bone end sclerosis described as follows: grade 0: normal joint; grade 1: minute osteophytes of doubtfull significance; grade 2: definite osteophytes; grade 3: moderate diminution of joint space; grade 4: joint space greatly impaired, subchondral sclerosis. Until now, the K&L scale has never been validated in the ankle. Our objective was to assess the usefulness of the K&L scale for the ankle joint, by determining its reliability and by comparing it to functional scores and to computerized minimal joint space width (minJSW) and sclerosis measurements. Additionally we propose an atlas of standardized radiographs for each of the K&L grades in the ankle. Methods. 73 patients 10 to 20 years post ankle ORIF were examined. Bilateral ankle radiographs were taken. Four physicians independently assessed the K&L grades and evaluated tibial and talar sclerosis on anteroposterior radiographs. Functional outcome was assessed with the AOFAS Hindfoot score. Bone density and minJSW were measured using a previously validated Ankle Image Digital Analysis software (AIDA). Results. The interobserver reliability, for the K&L stages was 0.60 (intraclass correlation coefficient) indicating moderate to good agreement. The mean AOFAS hindfoot score decreased substantially (p = 009) and linearly from 99.3 in K&L grade 0 to 79.5 points in K&L grade 4. The minJSW assessed by AIDA was similar among grades 0 to 2 (between 2 and 2.5mm), but significantly lower in grade 3 (1.8mm) and in grade 4 (1.1mm). A decreased minJSW less than 2mm, commonly used as a threshold for the assessment of hip and knee OA, was found in 77% of K&L grades 3–4 compared to 33% of grades 0–2, sensitivity 77.4% and specificity 66.7%. Physician based assessment revealed that subchondral sclerosis was present in 16% of K&L grade 1 patients, 52% of grade 2, 70% of grade 3 and 100% of grade 4 patients. No correlation could be found between physician based assessment and digital image analysis of subchondral sclerosis. Conclusions. Interobserver reliability in assessment of ankle OA using the K&L scale was similar to other previously described joints. OA progression correlated with functional diminution. Joint space narrowing assessed AIDA as well as the cut-off of 2mm correlated well with the K&L scale. Overall, we recommend the use of the K&L scale for the radiographic assessment of ankle OA

Introduction: It is said that God gave us paired bilateral anatomical structures so that the trauma surgeon can compare the injured side with its uninjured counterpart. The axial rotational alignment of fingers, when disrupted by injury, may lead to scissoring. During examination, comparison is made between the rotational alignment of injured and uninjured fingers. This assumes that the rotational alignment of the fingers is symmetrical. A study was performed to ascertain normal rotational alignment, and establish whether this assumption is valid. Materials and Methods: Standardised digital images were taken with fingers in extension. These were analysed using the angle-measuring tool on Adobe Photoshop software. The rotational angle used was that between a line joining the radial and ulnar borders of the nail plate, and the horizontal. Results: Mean angles of rotation were 13° for the index finger, 10° for the middle, 5° for the ring and 12° for the little. Differences in the angle for ring and little fingers between the sides were not significant; these fingers are symmetrical. Index and middle fingers demonstrated statistically significant asymmetry of 2.6° (SD +/− 4.2°). Discussion: Previous work has sought to quantify rotational alignment in cadavers or using wire markers and fluoroscopy. A new method, using digital photography and image analysis is described. We determined mean angles, showing symmetry of the ring and little but asymmetry of index and middle. Previous work has suggested that up to 10° of rotation can be tolerated. With only 2.6° of difference, clinical comparison of sides remains appropriate

Introduction: Bone mineral density (BMD) has been shown to correlate well with strength and bending stiffness of bone. Following tibial diaphyseal fracture, reduction in the optical density of cancellous bony regions is apparent throughout the postoperative period. As much as 70% loss in BMD in the distal tibia and 45% in the proximal tibia has been reported. The process influencing the extent of such posttraumatic osteoporosis is multifactorial: the severity of injury, age of the patient, the effects of the regional acceleratory phenomenon (RAP), fixation type and onset of weight-bearing have all been implicated. Such loss in BMD in most cases is not fully recoverable and has been shown to increase subsequent fracture risk in the ipsilateral tibia and femur. It has been estimated that a 50% reduction in bone mineral content is required before changes are radiologically observed. Such changes in BDM however can be calculated post operatively from standardised orthogonal tibial digital images, following image density calibration and the utilisation of soft tissue subtraction techniques. Using these image density quantification techniques, a study was performed to examine and compare the effects of fixation of tibial fractures, with either Ilizarov or Intramedullary nail, on BMD in cancellous bone. Method: Twenty-nine patients were recruited in the context of a randomised controlled trial assessing the radiological outcome following the treatment of closed tibial diaphyseal fractures with either an Ilizarov fixator (n=15) or an intramedullary nail (n=14). Informed consent was obtained for AP and Lat radiograph examination at selected postoperative time intervals (1, 3, 6, 12, 26 and 52 weeks). At each visit the rotation of the patients’ limb was standardised using a position control device (jig). The exposure and image acquisition parameters were standardised and digital images analysed. Serial BMD values were calculated and changes throughout the postoperative period compared between treatment groups. Results: This study demonstrated considerable differences in the extent of disuse osteoporosis in the cancellous regions of the tibia following either Ilizarov fixation or intramedullary nailing. In the proximal metaphysic patients treated with a tibial nail displayed a reduction in BMD by 18.8% at 26 weeks and 25.7% at 42 weeks. In contrast, patients managed with Ilizarov fixation actually increased the BMD at this region at 26 weeks by 11.7% but with a final overall loss of 5.2% at 52 weeks. Each group demonstrated decreases in BMD at both the distal metaphysic and medial malleolar regions over 26 and 52 weeks. The BMD of the distal metaphysic decreased by 15.9% at 26 weeks and 35.3% at 52 weeks for patient treated with a nail, and reduced by 11.1% at 26 weeks and 0.76% at 52 weeks in patients treated with Ilizarov fixation. The medial malleolar region demonstrated the greatest decreases of all with a reduction in BDM of 43.1% and 66.4% in the nail group, and 34.9% and 61.6% in the Ilizarov group, at 26 and 52 weeks, respectively. Conclusion: The magnitude of disuse osteoporosis following tibial diaphyseal fractures treated with intramedullary nailing, calculated using digital image analysis, and demonstrates changes similar to those reported previously in the literature. The use of Ilizarov fixation however maintains proximal metaphyseal BMD throughout the review period and promotes remineralisation in the distal metaphysic. No difference is observed in the medial malleolus between the two groups. The benefits of axial loading, stability and preservation of intraosseus vascularity with the use of the Ilizarov fixator are clearly demonstrated in the results; preservation of BMD was also shown to correlate well with improved clinical outcome and will reduce future ipsilateral tibial and femoral fracture risk

Aims

The aims of this study were to develop an automatic system capable of calculating four radiological measurements used in the diagnosis and monitoring of cerebral palsy (CP)-related hip disease, and to demonstrate that these measurements are sufficiently accurate to be used in clinical practice.

Aims. Morphological abnormalities are present in patients with developmental dysplasia of the hip (DDH). We studied and compared the pelvic anatomy and morphology between the affected hemipelvis with the unaffected side in patients with unilateral Crowe type IV DDH using 3D imaging and analysis. Methods. A total of 20 patients with unilateral Crowe-IV DDH were included in the study. The contralateral side was considered normal in all patients. A coordinate system based on the sacral base (SB) in a reconstructed pelvic model was established. The pelvic orientations (tilt, rotation, and obliquity) of the affected side were assessed by establishing a virtual anterior pelvic plane (APP). The bilateral coordinates of the anterior superior iliac spine (ASIS) and the centres of hip rotation were established, and parameters concerning size and volume were compared for both sides of the pelvis. Results. The ASIS on the dislocated side was located inferiorly and anteriorly compared to the healthy side (coordinates on the y-axis and z-axis; p = 0.001; p = 0.031). The centre of hip rotation on the dislocated side was located inferiorly and medially compared to the healthy side (coordinates on the x-axis and the y-axis; p < 0.001; p = 0.003). The affected hemipelvis tilted anteriorly in the sagittal plane (mean 8.05° (SD 3.57°)), anteriorly rotated in the transverse plane (mean 3.31° (SD 1.41°)), and tilted obliquely and caudally in the coronal plane (mean 2.04° (SD 0.81°)) relative to the healthy hemipelvis. The affected hemipelvis was significantly smaller in the length, width, height, and volume than the healthy counterpart. (p = 0.014; p = 0.009; p = 0.035; p = 0.002). Conclusion. Asymmetric abnormalities were identified on the affected hemipelvis in patients with the unilateral Crowe-IV DDH using 3D imaging techniques. Improved understanding of the morphological changes may influence the positioning of the acetabular component at THA. Acetabular component malpositioning errors caused by anterior tilt of the affected hemi pelvis and the abnormal position of the affected side centre of rotation should be considered by orthopaedic surgeons when undertaking THA in patients with Crowe-IV DDH. Cite this article: Bone Joint J 2020;102-B(10):1311–1318

Aims. The surgical helmet system (SHS) was developed to reduce the risk of periprosthetic joint infection (PJI), but the evidence is contradictory, with some studies suggesting an increased risk of PJI due to potential leakage through the glove-gown interface (GGI) caused by its positive pressure. We assumed that SHS and glove exchange had an impact on the leakage via GGI. Methods. There were 404 arthroplasty simulations with fluorescent gel, in which SHS was used (H+) or not (H-), and GGI was sealed (S+) or not (S-), divided into four groups: H+S+, H+S-, H-S+, and H-S-, varying by exposure duration (15 to 60 minutes) and frequency of glove exchanges (0 to 6 times). The intensity of fluorescent leakage through GGI was quantified automatically with an image analysis software. The effect of the above factors on fluorescent leakage via GGI were compared and analyzed. Results. The leakage intensity increased with exposure duration and frequency of glove exchanges in all groups. When SHS was used and GGI was not sealed (H+S-), the leakage intensity via GGI had the fastest increase, consistently higher than other groups (H+S+, H-S+ and H-S-) after 30 minutes (p < 0.05) and when there were more than four instances of glove exchange (p < 0.05). Additionally, the leakage was strongly correlated with the duration of exposure (r. s. = 0.8379; p < 0.050) and the frequency of glove exchange (r. s. = 0.8198; p < 0.050) in H+S-. The correlations with duration and frequency turned weak when SHS was not used (H-) or GGI was sealed off (S+). Conclusion. Due to personal protection, SHS is recommended in arthroplasties. Meanwhile, it is strongly recommended to seal the GGI of the inner gloves and exchange the outer gloves hourly to reduce the risk of contamination from SHS. Cite this article: Bone Jt Open 2023;4(11):859–864

Introduction and Objective. Type 2 diabetes mellitus (T2DM), and the often concurrent obesity, causes metabolic changes that affect many organs and tissues, including bone. Despite a normal or even higher bone mineral density (BMD), T2DM has often been associated with a higher fracture risk, indicating a compromised bone quality. In this work, we use a novel congenic leptin receptor-deficient BioBreeding Diabetes Resistant rat (BBDR.cg.lepr.cp) to investigate the impact of T2DM and obesity on bone morphology and architecture at the microscale. Materials and Methods. Two different anatomical locations, i.e., femur and cranium, were studied combining micro-computed X-ray tomography (micro-CT) with scanning electron microscopy (SEM). Micro-CT data were examined using advanced image analysis tools in three-dimensions (3D). Results. Both parietal bones and femurs were smaller, i.e., thinner and shorter, respectively, in diabetic animals compared to healthy controls. Image analysis of the sagittal suture revealed a reduced suture width and length in diabetic animals, suggesting an altered bone apposition rate. Histomorphometry analysis from micro-CT data highlighted differences in microstructure of both trabecular and cortical femur between diabetic and healthy rats. In particular, bone volume fraction (BV/TV) was lower in the T2DM group, while trabecular spacing (Tb.Sp) was increased, overall indicating a higher porosity in diabetic trabecular bone. SEM revealed the presence of extended portions of hyper-mineralized cartilage in the distal femur of the diabetic animals. Conclusions. Micro-CT analyses, combined with SEM imaging, suggest that T2DM impacts bone growth and remodelling, in turn leading to differences in the structural organization at the microscale

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

Anterior vertebral body tethering (AVBT) is a growth modulating procedure used to manage idiopathic scoliosis by applying a flexible tether to the convex surface of the spine in skeletally immature patients. The purpose of this study is to determine the preliminary clinical outcomes for an adolescent patient cohort. 18 patients with scoliosis were selected using a narrow selection criteria to undergo AVBT. Of this cohort, 11 had reached a minimum follow up of 2 years, 4 had reached 18 months, and 3 had reached 6 months. These patients all demonstrated a primary thoracic deformity that was too severe for bracing, were skeletally immature, and were analysed in this preliminary study of coronal plane deformity correction. Using open-source image analysis software (ImageJ, NIH) PA radiographs taken pre-operatively and at regular follow-up visits post-operatively were used to measure the coronal plane deformity of the major and compensatory curves. Pre-operatively, the mean age was 12.0 years (S.D. 10.7 – 13.3), mean Sanders score 2.6 (S.D. 1.8-3.4), all Risser 0 and pre-menarchal, with mean main thoracic Cobb angle of 52° (S.D. 44.2-59.8°). Post-operatively the mean angle decreased to 26.4° (S.D. 18.4-32°) at 1 week, 30.4° (S.D. 21.3-39.6°) at 2 months, 25.7° (S.D. 18.7-32.8°) at 6 months, 27.9° (S.D. 16.2-39.6°) at 12 months, and 36.8° (S.D. 22.6– 51.0°) at 18 months and 38.2° (S.D. 27.6-48.7°) at 2 years. The change in curve at 2 years post-operative was statistically significant (P=0.004). There were 4 tether breakages identified that did not require return to theatre as yet, one patient underwent a posterior spinal instrumented fusion due to curve progression. AVBT is a promising new growth modulation technique for skeletally immature patients with progressive idiopathic scoliosis. This study has demonstrated a reduction in scoliosis severity

Abstract. Objective. The preparation of host degenerate cartilage for repair typically requires cutting and/or scraping to remove the damaged tissue. This can lead to mechanical injury and cartilage cell (chondrocytes) death, potentially limiting the integration of repair material. This study evaluated cell death at the site of cutting injury and determined whether raising the osmotic pressure (hyper-osmolarity) prior to injury could be chondroprotective. Methods. Ex vivo human femoral head cartilage was obtained from 13 patients (5 males and 8 females: 71.8 years old) with Ethical Permission and Patient consent. Cartilage wells were created using 3 or 5mm biopsy punches. Cell death at the wounded edge of the host cartilage and the edge of the extracted explants were assessed by quantifying the percentage of cell death (PCD) and measuring the width of the cell death zone at identified regions of interest (ROI) using the confocal laser scanning microscopy and image analysis software. To assess the chondroprotective effect of hyper-osmolarity, cartilage specimens were incubated in 340 or 600mOsm media, five minutes prior to injury to allow the chondrocytes to respond to the altered osmolarity. Wounded cartilage explants and cartilage wells were then cultured for a further 150 minutes following injury. Results. In 340mOsm media, the PCD around the 3mm cartilage wells was significantly less compared to the corresponding explants (20.05±10.24% vs 35.25±4.86%; P=0.0003). When using the 5mm biopsy punch, the PCD at the wound edges was significantly lower when compared to the 3mm cartilage wells (13.33±7.80% vs 20.05±10.24%; P=0.0121) at the same osmolarity. The width of the cell death zone for the well edges for both 3 and 5mm punches was significantly narrower when compared to their corresponding harvested cartilage explants in 340mOsm media (P<0.0001; P=0.0218, respectively). Exposing cartilage to raised osmolarity (600mOsm) prior to injury significantly reduced the PCD for cartilage wells produced by the 3mm biopsy punches (from 20.05±10.24% to 12.24±6.00%; P=0.0025). In addition, the zone of cell death was marginally reduced at the edges of the 5mm cartilage wells (19.25±15.78mm to 12.72±9.09mm; P=0.0499). Conclusions. The choice of biopsy punch and the osmolarity of the incubation medium prior to cartilage injury markedly affected the extent of chondrocyte death both at the edges of the cartilage wells and the explants. The smaller biopsy punch caused more chondrocyte death in the native cartilage wells compared to the larger punch, but this could be compensated for by the chondroprotective effect of raising the osmotic pressure. In general, there was less cell death at the wounded edges of the cartilage wells, compared to the explants. These results suggest that there is scope for further optimising the cutting implements used to create the cartilage wells and protecting chondrocytes by hyper-osmolarity in order to minimize cell death at cut edges and potentially enhance integration between cartilage repair material and host cartilage. 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

Introduction and Objective. Chronic tendinopathy is a multifactorial disease and a common problem in both, athletes and the general population. Mechanical overload and in addition old age, adiposity, and metabolic disorders are among the risk factors for chronic tendinopathy but their role in the pathogenesis is not yet unequivocally clarified. Materials and Methods. Achilles tendons of young (10 weeks) and old (100 weeks) female rats bred for high (HCR) and low (LCR) intrinsic aerobic exercise capacity were investigated. Both Achilles tendons of 28 rats were included and groups were young HCR, young LCR, old HCR, and old LCR (n = 7 tendons per group/method). In this rat model, genetically determined aerobic exercise capacity is associated with a certain phenotype as LCR show higher body weight and metabolic dysfunctions in comparison to HCR. Quantitative real-time PCR (qPCR) was used to evaluate alterations in gene expression. For histological analysis, semi-automated image analysis and histological scoring were performed. Results. Age-related downregulation of tenocyte marker genes (Tenomodulin), genes related to matrix modelling and remodeling (Collagen type 1, Collagen type 3, Elastin, Biglycan, Fibronectin, Tenascin C), and Transforming growth factor beta 3 (Tgfb3) were detected in tendons from HCR and LCR. Furthermore, inflammatory marker Cyclooxygenase 2 (Cox2) was downregulated, while Microsomal prostaglandin E synthase 2 (Ptges2) was upregulated in tendons from old HCR and old LCR. No significant alteration was seen in Interleukin 6 (Il6), Interleukin 1 beta (Il1b), and Tumor necrosis factor alpha (Tnfa). Histological analysis revealed that Achilles tendons of old rats had fewer and more elongated tenocyte nuclei compared to young rats, indicating a reduced metabolic activity. Even though higher content of glycosaminoglycans as a sign of degeneration was found in tendons of old HCR and LCR, no further signs of tendinopathy were detectable in histological evaluation. Conclusions. Overall, aging seems to play a prominent role in molecular and structural alterations of Achilles tendon tissue, while low intrinsic exercise capacity did not cause any changes. Even though tendinopathy was not present in any of the groups, some of the shown age-related changes correspond to single characteristics of chronic tendon disease. This study gives an insight into tendon aging and its contribution to molecular and cellular changes in Achilles tendon tissue

Joint surface restoration of deep osteochondral defects represents a significant unmet clinical need. Moreover, untreated lesions lead to a high rate of osteoarthritis. The current strategies to repair deep osteochondral defects such as osteochondral grafting or sandwich strategies combining bone autografts with ACI/MACI fail to generate long-lasting osteochondral interfaces. Herein, we investigated the capacity of juvenile Osteochondral Grafts (OCGs) to repair osteochondral defects in skeletally mature animals. With this regenerative model in view, we set up a new biological, bilayered, and scaffold-free Tissue Engineered (TE) construct for the repair of the osteochondral unit of the knee. Skeletally immature (5 weeks old) and mature (11 weeks old) Lewis rats were used. Cylindrical OCGs were excised from the intercondylar groove of the knee of skeletally immature rats and transplanted into osteochondral defects created in skeletally mature rats. To create bilayered TE constructs, micromasses of human periosteum-derived progenitor cells (hPDCs) and human articular chondrocytes (hACs) were produced in vitro using chemically defined medium formulations. These constructs were subsequently implanted orthotopically in vivo in nude rats. At 4 and 16 weeks after surgery, the knees were collected and processed for subsequent 3D imaging analysis and histological evaluation. Micro-computed tomography (µCT), H&E and Safranin O staining were used to evaluate the degree of tissue repair. Our results showed that the osteochondral unit of the knee in 5 weeks old rats exhibit an immature phenotype, displaying active subchondral bone formation through endochondral ossification, the absence of a tidemark, and articular chondrocytes oriented parallel to the articular surface. When transplanted into skeletally mature animals, the immature OCGs resumed their maturation process, i.e., formed new subchondral bone, partially established the tidemark, and maintained their Safranin O-positive hyaline cartilage at 16 weeks after transplantation. The bilayered TE constructs (hPDCs + hACs) could partially recapitulate the cascade of events as seen with the immature OCGs, i.e., the regeneration of the subchondral bone and the formation of the typical joint surface architecture, ranging from non-mineralized hyaline cartilage in the superficial layers to a progressively mineralized matrix at the interface with a new subchondral bone plate. Cell-based TE constructs displaying a hierarchically organized structure comprising of different tissue forming units seem an attractive new strategy to treat osteochondral defects of the knee

Introduction. Decreasing tissue damage and recovery time, while improving quality of life have been the focus of many approaches to total hip arthroplasty (THA). In this study, we compared two approaches, a tissue-sparing superior capsulotomy percutaneously assisted approach (SP) and the traditional posterior approach (TR), to address the question of whether the novel technique reduces tissue damage. The secondary aim of this study focused on the measurement technologies utilized to quantify the damage resulting from either SP or TR. Image J, BioQuant, and cellSens were the image analysis programs employed. Statistical validation and comparisons of results between all platforms were performed. Methods. Both hips of freshly frozen cadaveric specimens (n = 8) were surgically prepared for THA with random procedure performed on left or right hip. All selected specimens had no prior implantation of devices to ensure all observed muscle damage occurred from the surgical technique. Surgeons resected tissue and performed necessary procedural steps up to device implantation. No devices were implanted during the study, as the aim was to quantify the damage caused by the incision and resection. After completion of the surgery, an independent surgeon (IS), who was blinded as to which method was performed on the specimen, excised the muscles and inspected areas of interest Assessment of the tissue damage was executed using a midsubstance cross-sectional area technique, validated by prior studies. High-resolution images of demarcated muscles were used for quantitative analysis. Three blinded independent reviewers quantified damaged tissue. The results were used to detect if statistically significant differences were present between the two methods. Furthermore, an independent reviewer using SPSS statistical software also assessed inter-program and inter-rater reliability. Results. The SP procedure significantly reduced percent of damaged GM tissue. GS tissue damage reduction with SP procedure was observed but the difference was not statistically significant. Between raters, the intraclass correlation coefficient (ICC) for the tissue damage measures was 0.870 (95% CI: 0.824 – 0.907). Within the individual applications, BioQuant and Image J had ICCs of 0.972 and 0.987, respectively. CellSens, however had an ICC value of 0.671. Discussion. For the three image analysis programs chosen, the damaged tissue was quantified within the software application and each user defined areas of interest slightly different, which reduced the interrater reliability. However, variation in the software may affect the degree of difference detected and/or the p-value. There was a statistically significant reduction in percent of damaged tissue, SP vs. TR, in the GM obtained from all programs. A statistically significant reduction in GS damage, SP vs. TR, was not detected in either program, which may be a result of the limited sample size. Significance. New surgical techniques require evaluation to determine if there are objective advantages over other techniques. Preclinical evaluation of these techniques has been limited. Providing quantitative evidentiary support has clinical and scientific relevance to patients, physicians, and healthcare providers.. Independent analysis of these results may depend on the user interface of image analysis programs and should be evaluated by multiple raters to ensure accuracy

Juvenile Osteochondritis dissecans (JOCD) in humans and subchondral cystic lesions (SCL) in horses (also termed radiolucencies) share similarities: they develop in skeletally immature individuals at the same location in the medial femoral condyle (MFC) and their etiology is only partially understood but trauma is suspected to be involved. JOCD is relatively uncommon in people whereas SCLs arise in 6% of young horses leading to lameness. Ischemic chondronecrosis is speculated to have a role in both osteochondrosis and SCL pathogenesis. We hypothesize that MFC radiolucencies develop very early in life following a focal internal trauma to the osteochondral junction. Our aims were to characterize early MFC radioluciencies in foals from 0 to 2 years old. Distal femurs (n=182) from Thoroughbred horses (n=91, 0–2 years old), presented for post-mortem examination for reasons unrelated to this study, were collected. Radiographs and clinical tomodensitometry were performed to identify lesions defined as a focal delay of ossification. Micro-tomodensitometry (m-CT) and histology was then performed on the MFCs (CT lesions and age-matched subset of controls). Images were constructed in 3D. The thawed condyles, following fixation, were sectioned within the region of interest, determined by CT lesion sites. Hematoxylin eosin phloxin and safran (HEPS) and Martius-Scarlet-Blue (MSB) stains were performed. Histological parameters assessed included presence of chondronecrosis, fibrin, fibroplasia and osteochondral fracture. An additional subset of CT control (lesion-free) MFCs (less 6 months old) were studied to identify early chondronecrosis lesions distant from the osteochondral junction. One MFC in clinical CT triages controls had a small lesion on m-CT and was placed in the lesion group. All m-CT and histologic lesions (n=23) had a focal delay of ossification located in the same site, a weight bearing area on craniomedial condyle. The youngest specimen with lesions was less than 2 months old. On m-CT 3D image analysis, the lesions seemed to progressively move in a craniolateral to caudomedial direction with advancing age and development. Seventy-four percent (n=17/23) of the lesions had bone-cartilage separation (considered to be osteochondral fractures) confirmed by the identification of fibrin/clot on MSB stains, representing an acute focal bleed. Fibroplasia, indicating chronicity, was also identified (74%, n=17/23). In four cases, the chondrocytes in the adjacent cartilage were healthy and no chondronecrosis was identified in any sections in the lesions. Nineteen cases had chondronecrosis and always on the surface adjacent to the bone, at the osteochondral junction. None of the subset of control specimens, less than 6 months old (n=44), had chondronecrosis within the growth cartilage. Early subchondral cystic lesions of the medial femoral condyle may arise secondary to focal internal trauma at the osteochondral junction. The presence of fibrin/clot is compatible with a recent focal bleed in the lesion. Medial femorotibial joint internal forces related to geometry could be the cause of repetitive trauma and lesion progression. In the juvenile horse, and potentially humans, the early diagnosis of MFC lesions and rest during the susceptible period may reduce progression and promote healing by prevention of repetitive trauma, but requires further study

The purpose of this research was to determine the feasibility of radiostereometric analysis (RSA) as a diagnostic tool for assessing non-union following spinal arthrodesis procedures. Further, to estimate clinical thresholds for precision and accuracy of the proposed method in the cervical and lumbar spine. A three-level lumbo-sacral and a four-level cervical posterior arthrodesis procedures were performed on an artificial spine model (Sawbones, WA). Using a spring loaded inserter (RSA Biomedical, Sweden), eight to ten RSA markers were placed within each of the L4 and L5 segments in the spinous process (L4 only), lamina, transverse processes, posterior and anterior (down the pedicle) wall of the vertebral body. Eight to ten markers were placed within the proximal sacrum (S1) at the medial and lateral crests, tuberosity, and within the sacral canal wall. Four to eight RSA markers were placed into the C3-C6 lateral masses. Titanium screws and rods were applied to the spinal segments. Identical procedures were then performed on a cadaveric spine using similar bead placement and hardware. RSA imaging consisted of 12 double exams (24 exams) of the cervical and lumbar regions for both the Sawbones and cadaveric spine to assess precision of measurement under zero-displacement conditions. The most distal vertebrae were considered the datum against which the movement of all other vertebrae was compared. The artificial spine was then dismantled for accuracy assessment in which the middle vertebrae (L5 and C4-C5) were moved relative to the superior (L4 and C3) and inferior (S1 and C6) vertebrae by known, incremental displacements on an imaging phantom device. Displacements occurred along the superior-inferior, anterior-posterior, and flexion-extension (rotational) axes of motion. RSA images were obtained at each displacement. Image analysis was performed using model-based software (RSACore v3.41, Leiden, Netherlands) to visualize implanted RSA beads in 3-D space. Precision was defined as the 95% confidence interval of error in measuring zero-displacement. Accuracy was defined as the mean difference (with 95% confidence interval) between the known and measured displacement. The rate of RSA bead detection was high with 5–8 implanted beads being visible in both the lumbar and cervical regions of the artificial and cadaveric spines. Translational RSA precision for both spines was better than 0.25 mm and 0.82 mm for the lumbar and cervical regions, respectively. Rotational precision was better than 0.40° and 1.9° for the lumbar and cervical regions, respectively. RSA accuracy for the artificial spine overall demonstrated less than 0.11 mm translational bias (margin < ±0.02 mm) and less than 0.22° rotational bias (margin < ±0.15°). This study demonstrates that RSA achieves sufficient precision and accuracy to detect intervertebral micromotion for the purpose of assessing arthrodesis. Well dispersed RSA bead placement is critical to achieving sufficient accuracy as well as avoiding occlusion by metal hardware. Cervical bead implantation is particularly sensitive to bead clustering due to small vertebrae size and proximity to critical structures. The results of this work will aid in the development of a clinical study to assess arthrodesis in patients