This review briefly summarises some of the definitive studies of articular cartilage by microscopic MRI (µMRI) that were conducted with the highest spatial resolutions. The article has four major sections. The first section introduces the cartilage tissue, MRI and µMRI, and the concept of image contrast in MRI. The second section describes the characteristic profiles of three relaxation times (T. 1. , T. 2. and T. 1ρ. ) and self-diffusion in healthy articular cartilage. The third section discusses several factors that can influence the visualisation of articular cartilage and the detection of cartilage lesion by MRI and µMRI. These factors include image resolution, image analysis strategies, visualisation of the total tissue, topographical variations of the tissue properties, surface fibril ambiguity, deformation of the articular cartilage, and cartilage lesion. The final section justifies the values of multidisciplinary imaging that correlates MRI with other technical modalities, such as optical imaging. Rather than an exhaustive review to capture all activities in the literature, the studies cited in this review are merely illustrative

Magnetic resonance imaging (MRI) is the gold standard for the diagnosis of the pathologies affecting the glenohumeral joint and the rotator cuff diseases. MRI allows to highlight anatomic discontinuities of both muscles and tendons. However, MRI diagnostic accuracy has not proven to be highly sensitive in distinguishing between a partial-thickness tear and a full-thickness rotator cuff tear. The purpose of this study was to determine if MRI under axial traction can be helpful in increasing MRI sensitivity to identify partial-thickness rotator cuff tears. The study included 10 patients (4 males and 6 females) who had clinical examination and MRI suggesting a partial-thickness rotator cuff tear. They were candidates for shoulder arthroscopy because of persistent symptoms after at least three months of conservative treatment. The patients underwent a new MRI (under axial traction: MRI-AT) with a 4-kg weight applied to the affected arm. Then the patients underwent arthroscopy to confirm the diagnosis. Patients with a suspected full-thickness rotator cuff tear were excluded from the study. Patients’ average age was 52.4 years, and the dominant side was affected in 77.7% of the cases. Preoperative Constant-Murley Score was 57. MRI-AT showed that 3 patients were affected by a complete tear of the rotator cuff, 3 patients by a partial-thickness rotator cuff tear and 4 patients had no lesion. The analysis of data showed that: under axial traction the subacromial space increased by 0,2 mm (P value = 0,001075), the superior glenohumeral space decreased by 2.4 mm (P value = 0,07414), the inferior glenohumeral space increased by 0.3 mm (P value = 0,02942), the acromial angle decreased by 1.9° (P value = 0,0002104) and the acromion-glenohumeral angle decreased by 0.3° (P-value = 0,01974). Two experienced evaluators analyzed previous standard MRI and MRI-AT scans in a double-blinded fashion, with inter-rater evaluation of all the images and measures. Intraclass correlation coefficient (ICC) has been utilized to assess the reliability of the measures performed by different operators. ICC always resulted in more than 0.7, showing a high concordance among values in the same group. A comparative evaluation between standard MRI and MRI-AT has been conducted to highlight possible discrepancies and this has been compared to intraoperative findings. Concordance of the values was 89% between standard MRI and MRI-AT and 100% between MRI under axial traction and intraoperative findings. This study showed a high correlation between the diagnosis achieved with MRI-AT and the intraoperative arthroscopic findings. The use of MRI-AT in clinical practice may improve the diagnostic sensitivity of this method to detect a partial-thickness rotator cuff tear

In current practice in the UK there are three main approaches to investigating suspected scaphoid fractures not seen on initial plain film x-rays. Early MRI of all cases. Review all cases in clinic at two weeks with repeat x-rays. Hybrid model. Virtual Fracture Clinic (VFC) triage to reduce those who are seen in clinic at two weeks by:. ∘. Organising early MRI for those with high-risk presentation. ∘. Discharging those with an alternative more likely diagnosis. Our unit uses the VFC model. We aimed to evaluate its efficiency, safety, clinical outcomes and economic viability. All patients attending the emergency department with either a confirmed or suspected scaphoid fracture between March and December 2020 were included (n=305). Of these 297 were referred to the VFC: 33 had a confirmed fracture on x-ray and 264 had a suspected fracture. Of the suspected fractures reviewed in VFC 14% had an MRI organised directly owing to a high-risk presentation, 79% were brought for fracture clinic review and 17% discharged with an alternative diagnosis such as osteoarthritis. Of those subsequently reviewed in fracture clinic at two weeks: 9% were treated as scaphoid fractures (based on clinical suspicion and repeat x-rays), 17% had MRI or CT imaging organised, 5% did not attend and 69% were discharged. Overall, 17% of cases initially triaged, had further imaging – 41 MRIs and 5 CTs. MRI detected: 5% scaphoid fracture, 17% other fracture, 24% bone contusion, complete ligament tear 10%, partial ligament tear 39% and normal study 10%. The results of MRI minimally affected management. 3 patients were taken out of plaster early, 1 patient was immobilized who was not previously and no patients underwent operative management. In the following 12-month period one patient re-presented with a hand or wrist issue. This approach avoided 218 MRIs, equating to £24000 and 109 hours of scanner time. VFC triage and selective use of MRI scanning is a safe, efficient and cost-effective method for the management suspected scaphoid fractures. This can be implemented in units without the resource to MRI all suspected scaphoid fractures from the emergency department

Using deep learning and image processing technology, a standardized automatic quantitative analysis systerm of lumbar disc degeneration based on T2MRI is proposed to help doctors evaluate the prognosis of intervertebral disc (IVD) degeneration. A semantic segmentation network BianqueNet with self-attention mechanism skip connection module and deep feature extraction module is proposed to achieve high-precision segmentation of intervertebral disc related areas. A quantitative method is proposed to calculate the signal intensity difference (SI) in IVD, average disc height (DH), disc height index (DHI), and disc height-to-diameter ratio (DHR). According to the correlation analysis results of the degeneration characteristic parameters of IVDs, 1051 MRI images from four hospitals were collected to establish the quantitative ranges for these IVD parameters in larger population around China. The average dice coefficients of the proposed segmentation network for vertebral bodies and intervertebral discs are 97.04% and 94.76%, respectively. The designed parameters of intervertebral disc degeneration have a significant negative correlation with the Modified Pfirrmann Grade. This procedure is suitable for different MRI centers and different resolution of lumbar spine T2MRI (ICC=.874~.958). Among them, the standard of intervertebral disc signal intensity degeneration has excellent reliability according to the modified Pfirrmann Grade (macroF1=90.63%~92.02%). we developed a fully automated deep learning-based lumbar spine segmentation network, which demonstrated strong versatility and high reliability to assist residents on IVD degeneration grading by means of IVD degeneration quantitation

Painful OA is linked to CNS changes in pain processing. Temporal summation of pain (TSP) is a measure of one such CNS change, central sensitization. TSP is defined using a series (≥0.33Hz) of painful stimuli and is a predictor of postoperative pain, experienced by 20% of patients after total knee replacement (TKR) surgery. This study has developed a protocol to use functional MRI to assess CNS changes in OA pain processing. This pilot includes 3 participants with chronic knee OA pain awaiting TKR (62 ± 4.4) and 5 healthy volunteers (50 ± 13.6). 3-Tesla BOLD fMRI brain scans were recorded during short series of one second painful stimuli, applied using an automated inflatable cuff to the calf muscle of the leg with the affected knee or left side in healthy volunteers. The pain intensity at onset and during the 10 painful stimuli were recorded using a numerical rating scale. The pattern of brain activation was averaged across noxious stimuli, and the differential activation compared the 1st vs. 10th (last) stimulus. Bone marrow lesions (BMLs), synovitis and effusion size were scored from 3-Tesla knee MRI's using MOAKS scoring. TSP was raised in OA patients compared to control group (p=0.023). TSP brain activity in the chronic OA patients displayed higher signal within the subgenual anterior cingulate (sgACC) compared to healthy volunteers. Knee MRI identified OA patient's exhibited higher BML scores (p=0.038) and more knee effusion (p=0.018), but the lack of synovitis did not differ from control group (p=0.107). Enhanced TSP in chronic knee OA pain may be linked with augmented responses in emotional circuitry. BMLs and effusion size appear to contribute more with pain than synovitis. These results may help understand sensitization to improve outcomes for patients with knee OA undergoing TKR surgery

Abstract. Objectives. Magnetic resonance imaging (MRI) is one of the most widely used investigations for knee pain as it provides detailed assessment of the bone and soft tissues. The aim of this study was to report the frequency of each diagnosis identified on MRI scans of the knee and explore the relationship between MRI results and onward treatment. Methods. Consecutive MRI reports from a large NHS trust performed in 2017 were included in this study. The hospital electronic system was consulted to identify whether a patient underwent x-ray prior to the MRI, attended an outpatient appointment or underwent surgery. Results. 4466 MRI knees were performed in 2017 with 71.2% requested in primary care and 28.1% requested in secondary care. The most common diagnosis was signs of arthritis (55.2%), followed by meniscal tears (42.8%) and ACL tears (8.3%). 49.4% of patients who had an MRI attended outpatients and 15.6% underwent surgery. The rate of knee surgery was significantly higher for patients who had their scans requested in secondary care (32.9% vs 8.9%, p < 0.001). Conclusion. The rate of surgical intervention following MRI is low and given these results it seems unlikely that the scan changes practice in most cases. The rate of surgery and outpatient follow up was significantly higher in scans requested by secondary care. We urge clinicians avoid wasteful use of MRI and recommend the use of plain radiography prior to MRI where arthritis may be present

The relationship of degeneration to symptoms has been questioned. MRI detects apparently similar disc degeneration and degenerative changes in subjects both with and without back pain. We aimed to overcome these problems by re-annotating MRIs from asymptomatic and symptomatic groups onto the same grading system. We analysed disc degeneration in pre-existing large MRI datasets. Their MRIs were all originally annotated on different scales. We re-annotated all MRIs independent of their initial grading system, using a verified, rapid automated MRI annotation system (SpineNet) which reported degeneration on the Pfirrmann (1-5) scale, and other degenerative features (herniation, endplate defects, marrow signs, spinal stenosis) as binary present/absent. We compared prevalence of degenerative features between symptomatics and asymptomatics. Pfirrmann degeneration grades in relation to age and spinal level were very similar for the two independent groups of symptomatics over all ages and spinal levels. Severe degenerative changes were significantly more prevalent in discs of symptomatics than asymptomatics in the caudal but not the rostral lumbar discs in subjects < 60 years. We found high co-existence of degenerative features in both populations. Degeneration was minimal in around 30% of symptomatics < 50 years. We confirmed age and disc level are significant in determining imaging differences between asymptomatic and symptomatic populations and should not be ignored. Automated analysis, by rapidly combining and comparing data from existing groups with MRIs and information on LBP, provides a way in which epidemiological and ‘big data’ analysis could be advanced without the expense of collecting new groups

The purpose of this investigation was to evaluate systematically the literature concerning biopsy, MRI signal to noise quotient (SNQ) and clinical outcomes in graft-maturity assessment after autograft anterior cruciate ligament reconstruction (ACLR) and their possible relationships. Methods: The systematic review was reported and conducted according to the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. Studies through May 2019 evaluating methods of intra-articular ACL autograft maturity assessment were considered for inclusion. Eligible methods were histologic studies of biopsy specimens and conventional MRI studies reporting serial SNQ and/ or correlation with clinical parameters. Ten biopsy studies and 13 imaging studies, with a total of 706 patients, met the inclusion criteria. Biopsy studies show that graft remodeling undergoes an early healing phase, a phase of remodeling or proliferation and a ligamentization phase as an ongoing process even 1 year after surgery. Imaging studies showed an initial increase in SNQ, peaking at approximately 6 months, followed by a gradual decrease over time. There is no evident correlation between graft SNQ and knee stability outcome scores at the short- and long-term follow-up after ACLR. The remodeling of the graft is an ongoing process even 1 year after ACLR, based on human biopsy studies. MRI SNQ peaked at approximately 6 months, followed by a gradual decrease over time. Heterogeneity of the MRI methods and technical restrictions used in the current literature limit prediction of graft maturity and clinical and functional outcome measures by means of MRI graft SNQ after ACLR

Adductor strain is a common injury among football players. The adductor muscle group contains the three adductor muscles. (adductor longus, magnus and brevis) Adductor longus muscle is a triangular-shaped long muscle. This muscle originates from the superior ramus of the pubic bone and inserted into the middle part of the linea aspera. Adductor longus muscle is the most commonly injured muscle of adductors. Sudden acceleration, jumping, stretching, and kicking the ball are common causes of an adductor injury. Adductor muscle strains can result in missed playing time for football players. We present a 26-year-old man soccer player with pain in the left groin and proximal thigh. The symptoms had started during training and after kicking the ball with left foot (dominant side), he felt an acute pain in the groin region and proximal thigh. Despite the injury, he managed to finish the training. The team physician examined the patient immediately after training. The range of motion of both hip joints was in normal ranges and mild pain with adduction. There was a palpable mass at the inner proximal thigh during contraction of adductor muscles. There was no history of groin pain or adductor problems before this injury. Conventional radiographs showed no osseous abnormalities. 36 hours after the injury, MRI revealed acute grade IIB strain in the left adductor longus muscle, including both superior and inferior parts of the muscle. A hematoma was observed in the superior part of the left adductor muscle, with a craniocaudal length of 42 millimeters. There was an adductor muscle strain with hyperintensity extending for a craniocaudal length of approximately 12 centimeters involving more than 50% crosses sectional diameter of the muscle belly. Conservative treatment started immediately, consisting of cold therapy and soft tissue massage. Compression of the injured tissue using a 15-cm elastic bandage roll is done to limit bleeding and provide support. Iced water machine (Game Ready) was used. The team physician examined the player every day and prescribed physiotherapy protocol daily. Additionally, short interval follow-up MRI is used to evaluate the injury. (After 7 and 14 days of the injury) No injection was performed. The player is able to return to play immediately, despite MRI's strain images. The player started straight running 5 days later and joined to team training 8 days later and played 90 minutes-league-match 12 days after injury without any pain. No injection was performed. The player is able to return to play immediately, despite MRI's strain images. The player started straight running 5 days later and joined to team training 8 days later and played 90 minutes-league-match 12 days after injury without any pain. MRI is a useful technique in diagnosing trauma in football players presenting with groin pain. In this case, to estimate time-to-return-to-play, MRI alone is not strong evidence. MRI is a good option for follow up, but anamnesis and clinical examination is not inferior to diagnostic imaging

A risk factor for patellofemoral instability is trochlear dysplasia. Trochleoplasty is a surgical procedure used to reshape the trochlear groove to improve patellar stability. This study seeks to compare pre-op MRI measurements and post operative MRI measurements for patients who have undergone trochleoplasty in correlation with their clinical outcomes scores. Data was collected from a database of patients known to have trochlear dysplasia who underwent trochleoplasty. Radiological Data was collected pre-op and subsequent post op MRI data collected included TT-TG, Patella Tilt, IS, sulcus angle. Data score sheets pre-op and post op trochleoplasty completed by patients were also collected. 10 patients had pre and post op MRI's documented. 80%(8/10) females and 20%(2/10) males, average age of 30 years old (range 23 – 32 years old). Average MRI pre-op scores: IS ratio: 1.2, Patella tilt: 24.14, sulcus angle 160.13, and TT-TG distance of 16.94. 1 year average MRI post-op scores: IS ratio: 1.28, Patella tilt 15.56, sulcus angle 148.66 and TT-TG distance 16.78. 1 year post op Kujala and Norwich instability scores patient reported improved stability, function and confidence post op compared to pre-op. Subjective and objective scores reflected an improvement of stability. MRI demonstrated a deeper trochlear groove post-operatively which should provide resistance against lateral patella movement and patellar dislocations. TT-TG pre and post op remained constant. Pre op and post op Kujala scores reflected improved function. The Norwich instability scores pre and post op reflected satisfaction of treatment. There are not a lot of studies published on trochleoplasty. Based on this study it is clear that patients with patellofemoral instability with severe trochlear dysplasia will benefit from trochleoplasty. The sample size of the data analysis was only 10. However it reflected that function 1 year post procedure remained stable

Rotational laxity increases the risk of anterior cruciate ligament (ACL) injuries and residual rotational laxity can result in inferior surgical outcomes and risk of retears. The dynamic rotatory knee stability can be assessed through manual examination, but it is limited to the surgeon's experience and it provides inaccurate measurements, highlighting the need for objective measurement of knee rotational laxity. The objective measurement of knee laxity can help to better identify patients that may benefit from conservative treatment or those that require surgical treatment with or without concomitant extra-articular procedures. We rely in Porto Knee Testing Device (PKTD®) to accurately measure sagittal and rotatory laxity of the knee, either individually or in a combined fashion. The PKTD® is safe and can be used in combination with CT or MRI, which allows to assess both the “anatomy” and the “function” in the same examination. By this way, we may have a total ACL rupture and a stable knee not requiring surgery or, on the other hand, the same injury scenario but with an unstable knee that requires surgical intervention (with or without lateral extra-articular tenodesis). In cases of partial ACL tears, it may be possible to identify some ligamentous fibers that remain functional, where the conservative treatment or augmentation techniques can provide satisfactory results. It can also identify when a posteromedial or posterolateral instability is associated. The PKTD® can also be used to follow-up the laxity results of conservative and surgical procedures and contribute to the decision-making of return to sports

The modified Hedgehog technique was previously used to reattach pure chondral shear-off fragments in the pediatric knee. In the modified Hedgehog technique, the calcified side of chondral fragments is multiple times incised and trimmed obliquely for an interlocking fit in the defect site. Fibrin glue with or without sutures is subsequently applied to fix the fragment to the defect. This preliminary report further elucidates the potential of the technique by evaluation of its application in young adults using patient reported outcome measures (PROMs) and high-field Magnetic Resonance Imaging (MRI) as outcome measures. Three patients with a femoral cartilage defect (2 medial, 1 lateral), and a concomitant pure chondral corpus liberum were operatively treated by the modified Hedgehog technique. Age at surgery ranged from 20.6–21.2 years, defect size ranged from 3.8–6.0 cm2. Patients were evaluated at three months and one year after surgery by PROMs and 7.0T MRI. PROMs included the Internation Knee Documentation (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS) and Visual Analog Scale (VAS) questionnaires. 7.0T MRI (Magnetom, Siemens Healthcare, Erlangen, Germany) using a 28-channel proton knee coil (QED, Electrodynamics LLC, Cleveland, OH) included a proton density weighted turbo spin-echo sequence with fat suppression to assess morphological tissue structure andgagCEST imaging to measure the biochemical tissue composition in terms of glycosaminoglycans (GAG). Twelve months after surgery all patients reported no pain and showed full range of motion. While PROMs at three months showed large variability between patients, one year after surgery the scores were consistently improved. Over time, morphological MRI visualized improvements in integration of the cartilage fragment with the surrounding cartilage, which was supported by biochemical MRI showing increased GAG values at the defect edges. Statistics were not applied to the results because of the small sample size. The modified Hedgehog technique in young adults with an acute onset caused by a pure chondral corpus liberum can be considered promising. The improved PROM results over time were supported by 7.0T MRI that visualized improvements in tissue structure and biochemical composition. Inclusion of more patients in future studies would allow statistical analysis and more conclusive results. The etiology of loosening and time between onset of symptoms and surgery for successful graft integration may differ between pediatric and young adult patients and is subject for future studies

Magnetic resonance imaging (MRI) is a useful diagnostic tool in evaluating meniscus pathology in the knee. Data from available literature suggests sensitivity and specificity rates around 90% when compared to the gold standard findings at knee arthroscopy. We sought to evaluate the sensitivity, specificity and precision rate (positive predictive value) of MRI at diagnosing meniscus tears within our unit. A retrospective audit of a total of 79 MRI reports and arthroscopic findings spanning a one year period was carried out. There were 66 positive MRI reports and 13 negative reports. There were 6 false positives 4 false negatives when compared to arthroscopic findings. The sensitivity of MRI for detecting meniscus tears was 93.7% with 60 out of 64 tears detected. All 4 false negatives also had at least grade III osteoarthritic changes at arthroscopy. Specificity was rather low at 60% with MRI reporting 6 tears (false positives) out of 15 patients who had no tears found at arthroscopy. The positive predictive value (precision rate) of MRI detecting tears was 90.9%. This data shows that MRI in our unit has a comparable high sensitivity to that in various literature making it a useful tool at ruling out disease with a negative result in the clinical setting. A more useful parameter in the clinical setting is its high precision rate when faced with a positive result. However, its specificity is much lower than that in most published data. A total of 6 tears on MRI turned out not to be on arthroscopy meaning patients could have been subjected to an avoidable invasive procedure in the absence of any other indication. This highlights the importance of obtaining reports from experienced musculoskeletal radiologists and the need for surgeons to review MRI images and match them to clinical information prior to subjecting patients to surgery

In this study, we evaluated the labrum tear using radial sequence 3D Multiple Echo Recombined Gradient Echo (MERGE) MRI without arthrography based on modified Czerny's classification, comparing with actual arthroscopic findings. A total of 61 hips including 27 hips of femoroacetabular impingement (FAI), 19 hips of borderline development dysplasia of the hip (BDDH) and 15 hips of early stage osteoarthritis (OA) were enrolled this retrospective study. MRI findings evaluated in each three regions of interest; anterior region, anterolateral region, and lateral region. The cases with severe degeneration that is not concordant with any original Czerny's classification is defined as stage4. We compared MRI findings with arthroscopic findings and calculated the sensitivity, specificity, and likelihood ratio in terms of the existence of labrum tear. MRI findings revealed labrum tear more frequently in anterolateral than lateral (p<0.001). Especially in FAI group, labrum tear was more frequently observed by MRI in anterolateral than lateral (p=0.006). In comparison with MRI findings and arthroscopic findings, the sensitivity was 97%, specificity was 79% and likelihood ratio was 4.59 as average of all regions in terms of the existence of labrum tear. In each region, sensitivity and specificity was 97% and 50% in anterior, 97% and 100% specificity in anterolateral, 94% and 81% in lateral, respectively. Thus, MERGE MRI revealed excellent sensitivity and specificity for diagnosis of labrum tear, especially in anterolateral region. The cases with severely degenerated labrum were classified as newly defined stage 4, which was recognized frequently in OA cases

Non-invasive, in vivo measurement of the three-dimensional (3-D) motion of the tibiofemoral joint is essential for the study of the biomechanics and functional assessment of the knee. Real-time magnetic resonance imaging (MRI) techniques enable the measurement of dynamic motions of the knee with satisfactory image quality and free of radiation exposures but are limited to planar motions in selected slice(s). The aims of the current study were to propose a slice-to-volume registration (SVR) method in conjunction with dual-slice, real-time MRI for measuring 3-D tibiofemoral motion; and to evaluate its repeatability during passive knee flexion. Eight healthy young adults participated in the current study, giving informed written consent as approved by the Institutional Research Board. A 3-T MRI system (Verio, Siemens, Erlangen, Germany) incorporated with a neck matrix coil was used to collect the MRI data. A 3-D scanning using the VIBE sequence was used to collect the volumetric data of the knee at fully extended position (TR = 4.64 ms, TE = 2.3 ms, flip angle = 15°, in-plane resolution = 0.39 × 0.39 mm. 2. and slice thickness = 0.8 mm). A real-time MRI using the refocused radial FLASH sequence (TR = 4.3 ms, TE = 2.3 ms, flip angle = 20°, in-plane resolution = 1.0 × 1.0 mm. 2. , slice thickness = 6 mm) was used to acquire a pair of image slices of the knee at a frame rate of 3 fps during passive flexion. The volumetric MRI data sets were segmented for the femur and tibia/fibula to isolate the sub-volumes containing bone segments. A slice-to-volume registration method was then performed to determine the 3-D poses of the bones based on the spatial matching between sub-volume of the bones and the real-time image slices. The bone poses for all frames were used to calculate the rigid-body kinematics of the tibiofemoral joint in terms of the flexion/extension (FE), internal/external rotation (IR/ER), abduction/adduction (Abd/Add) and joint center translations along three anatomical axis of the tibia. The procedures were carried out five times for repeatability analysis. The standard deviation (SD) of the rigid-body kinematics for each frame from the five trials were calculated and then averaged across all frames to give quantitative measures of the repeatability of the kinematic variables. The repeatability analysis showed that the mean±SD of the averaged SD in FE, Abd/Add and IR/ER components across all subjects were 0.25±0.09, 0.46±0.13 and 0.77±0.16 degrees, respectively. The corresponding values for the joint translations in anterior/posterior, proximal/distal and medial/lateral directions were 0.21±0.04, 0.11±0.03 and 0.43±0.09 mm. An SVR method in conjunction with dual-slice real-time MRI has been successfully developed and its repeatability in measuring 3-D motion of the tibiofemoral joint evaluated. The results show that the proposed method is capable of providing rigid-body kinematics with sub-millimeter and sub-degree precision (repeatability). The proposed SVR method using real-time MRI will be a valuable tool for non-invasive, functional assessment of the knee without involving ionizing radiation, and may be further developed for joint stability assessment

Background and Objectives. Triangular fibrocartilaginous complex (TFCC) tears are common sources of ulna sided wrist pain and resultant functional disability. Diagnosis is based on history, clinical examination and radiological evidence of a TFCC central perforation or radial/ulna tear. The purpose of this study is therefore to evaluate the diagnostic accuracy of Magnetic Resonance Imaging (MRI) and Magnetic Resonance Arthrography (MRA) in the detection of TFCC injury in the adult population. Methods. Published and unpublished literature databases were systematically review independently by two researchers. Two-by-two tables were constructed to calculate the sensitivity and specificity of MRI or MRA investigations against arthroscopic outcomes. Pooled sensitivity and specificity values and summary Receiver Operating Characteristic curve (sROC) evaluations were performed. Methodological quality of each study was assessed using the QUADAS (Quality Assessment of Diagnostic Accuracy Studies) tool. Results. Twenty one studies were eligible, including 910 wrists. On meta-analysis, MRA was superior to MRI in the investigation of complete TFCC tears with a pooled sensitivity of 0.75 (95% Confidence Interval (CI): 0.70, 0.79) and specificity of 0.81 (95% CI: 0.76, 0.86), compared to MRAs 0.84 (95% CI: 0.79, 0.89), and 0.95 (95% CI: 0.92, 0.98) respectively. MRA and MRI performed at greater field strengths reported greater sensitivity and specificity findings. For 3.0 Tesla (T) MRI, the meta-analysis indicated a sensitivity of 0.86 (95% CI: 0.65, 0.97), and specificity of 1.00 (0.87, 1.00). In comparison, the pooled sensitivity for the 1.5T MRI assessment was 0.70 (95% CI: 0.64, 0.75) and specificity of 0.79 (95% CI: 0.72, 0.85). This trend was repeated for MRA where 3.0T MRA exhibited a sensitivity was 1.00 (95% CI: 0.79, 1.00) and specificity of 1.00 (95% CI: 0.82, 1.00), whilst pooled analysis 1.5T MRA demonstrated a sensitivity of 0.83 (95% CI: 0.78, 0.89) and specificity of 0.95 (95% CI: 0.91, 0.98). There was insufficient data to assess the diagnostic test accuracy of partial TFCC lesions. Conclusions. Given its acceptable diagnostic test accuracy, it is recommended that in cases where there are questions over the diagnosis and subsequent management of patients with ulna wrist pain, a MRA should be undertaken rather than MRI

Introduction. Anteromedial osteoarthritis of the knee (anteromedial gonarthrosis-AMG) is a common form of knee arthritis. In a clinical setting, knee arthritis has always been assessed by plain radiography in conjunction with pain and function assessments. Whilst this is useful for surgical decision making in bone on bone arthritis, plain radiography gives no insight to the earlier stages of disease. In a recent study 82% of patients with painful arthritis had only partial thickness joint space loss on plain radiography. These patients are managed with various surgical treatments; injection, arthroscopy, osteotomy and arthroplasty with varying results. We believe these varying results are in part due to these patients being at different stages of disease, which will respond differently to different treatments. However radiography cannot delineate these stages. We describe the Magnetic Resonance Imaging (MRI) findings of this partial thickness AMG as a way of understanding these earlier stages of the disease. Method. 46 subjects with symptomatic partial thickness AMG underwent MRI assessment with dedicated 3 Tesla sequences. All joint compartments were scored for both partial and full thickness cartilage lesions, osteophytes and bone marrow lesions (BML). Both menisci were assessed for extrusion and tear. Anterior cruciate ligament (ACL) integrity was also assessed. Osteophytes were graded on a four point scale in the intercondylar notch and the lateral margins of the joint compartments. Scoring was performed by a consultant radiologist and clinical research fellow using a validated MRI atlas with consensus reached for disagreements. The results were tabulated and relationships of the interval data assessed with linear by linear Chi2 test and Pearson's Correlation. Results. All cases had medial femoral cartilage loss; 22% partial and 78% full thickness. 79% showed medial tibial loss, however in no cases was there medial tibial loss without femoral loss. 10 cases had lateral compartment partial thickness cartilage loss. Again, there was no tibial loss without femoral loss present. Increasing size of intercondylar notch osteophyte is associated with increasing ACL damage (p=0.001). Independent to this, increasing ACL damage is associated with lateral femoral condyle cartilage loss (p=0.002). Throughout the knee the incidence of BMLs increased with increasing cartilage loss (p=0.025). Only 13% of medial menisci were normal. As meniscal damage increases, so does the incidence of BMLs in the same compartment (p=0.03). Discussion. We describe the MRI findings of early AMG with partial thickness joint space loss. In all cases there was medial femoral loss, either with or without tibial loss. We believe the disease begins on the medial femoral condyle and progresses through the joint in stages. Later stages are associated with damage to the other structures in the knee, such as the meniscus and the ACL. Damage to the ACL is associated with increasing osteophytosis. This description is the first step in describing the stages of early AMG. Description of these stages is important since we believe the outcome of surgical intervention may be dependant on these and they may guide future therapy

Aim. The aim of this study is to outline the steps and techniques required to create a patient specific 3D printed guide for the accurate placement of the origin of the femoral tunnel for single bundle ACL reconstruction. Introduction. Placements of the femoral tunnels for ACL reconstruction have changed over the years. Most recently there has been a trend towards placing the tunnels in a more anatomic position. There has been subsequent debate as to where this anatomic position should be. The problem with any attempt at consensus over the placement of an anatomic landmark is that each patient has some variation in their positioning and therefore a fixed point for all has compromise for all as it is an average. Our aim was to attempt to make a cost effective and quick custom guide that could allow placement of the center of the patients’ newly created femoral tunnel in the mid position of their contralateral native ACL femoral footprint. Materials & Methods. We took a standard protocol MRI scan of a patient's knee without ACL injury transferred the DICOM files to a personal computer running OsiriX (Pixmeo, Geneva, Switzerland.) and analysed it for a series of specific anatomical landmarks. OsiriX is an image processing software dedicated to DICOM images. We marked the most posterior edge of the articular cartilage on the lateral wall of the notch (1), the most anterior edge of the articular cartilage of the lateral wall of the notch (2), the most inferior edge of the articular cartilage of the lateral wall of the notch (3) and the center of the femoral footprint of the native ACL. Distances were then calculated to determine the position relative to the three articular cartilage points of the center of the ACL footprint. These measurements and points were then utilised to create a 3D computer aided design (CAD) model of a custom guide. This was done using the 3D CAD program 123Design (Autodesk Ltd., Farnbourgh, Hampshire). This 3D model was then exported as an STL file suitable for 3D printing. The STL file was then uploaded to an online 3D printing service and the physical guide was created in transparent acrylic based photopolymer, PA220 plastic and 316L stainless steel. The models created were then measured using vernier calipers to confirm the accuracy of the final guides. Results. The MRI data showed point 1 (AP), point 2 (distal-ACL), point 3 (Ant-ACL) and point 4 (Post-ACL) at a distance of 59.83, 15, 45.8 and 13.9 respectively. For the 3D CAD model, points 1, 2, 3 and 4 were at a distance of 59.83, 15, 45.8 and 13.9 respectively. For the PA220 plastic model, points 1, 2, 3 and 4 were at a distance of 59.86, 14.48, 45.85 and 13.79 respectively. For the 316L stainless steel model, points 1, 2, 3 and 4 were at a distance of 59.79, 14.67, 45.64 and 13.48 respectively. Lastly, for the photopolymer model, points 1, 2, 3 and 4 were at a distance of 59.86, 14.2, 45.4 and 13.69 respectively. The p-value comparing MRI/CAD vs. PA220 was p=0.3753; for the comparison between MRI/CAD vs. 316L, p=0.0683; lastly for the comparison between MRI/CAD Vs. Photopolymer, p=0.3450. The models produced were accurate with no statistical difference in size and positioning of the center of the ACL footprint from the original computer model and to the position of the ACL from the MRI scans. The costs for the models 3D printed were £3.50 for the PA220 plastic, £15 for the transparent photopolymer and £25 for the 316L stainless steel. The time taken from MRI to delivery for the physical models was 7 days. Discussion. Articles regarding the creation of 3D printed custom ACL guides from the patients contralateral knee do not feature in current literature. There has been much research on custom guides for other orthopaedic procedures such as in total knee arthroplasty for the accurate placement of implants. There has also been research published on the creation of custom cutting jigs from CT for complex corrective osteotomy surgery. This study serves as the first step and a proof of concept for the accurate creation of patient specific 3D printed guides for the anatomical placement of the femoral tunnel for ACL reconstruction. The guides were easy to create and produce taking only a week and with a cost of between £3.50 and £25. The design of the guides was to allow the tip of a standard Chondro Pick (Arthrex inc., Naples, Florida.) (3mm) used to mark the starting point of the femoral tunnel to enter through the guide. The next step for this research is to create guides from cadaveric matched knees and utilise the guides to carry out the creation of the femoral tunnels and to analyse of the placement of the tunnel in relation to the contralateral knee

Summary Statement. Conventional imaging techniques lack the ability to objectively assess early stages of intervertebral disc degeneration, characterised by glycosaminoglycan loss. This study shows that MRI T2∗ mapping correlates positively with GAG content and that it provides continuous measurements for disc degeneration. Introduction. Early degenerative changes arise in the nucleus pulposus (NP) and are characterised by a loss of glycosaminoglycans (GAG). Early disc degeneration (DD) could possibly be treated with upcoming regenerative therapies (e.g. with stem cells and/or growth factors). In order to evaluate degeneration and treatments, a sensitive diagnostic tool is needed. While conventional magnetic resonance imaging (MRI) and x-ray techniques can detect late stages of DD, these techniques lack the ability to detect early degenerative changes. Recently, T2∗ mapping has been proposed as a new technique to evaluate early IVD degeneration, yet the correlation with GAG content and histological features has not been previously investigated. The objective of this study was to determine the value of T2∗ mapping in diagnosing DD by correlating this technique with the biochemical composition of IVDs. Materials & Methods. Six caprine lumbar spines obtained from an in vivo study and two healthy goat spines from the local abattoir, encompassing a total of 48 IVDs, were examined using sagittal standard T2-weighted and T2∗ mapping MRI protocols at 1.5 Tesla. Regions of interest (ROIs) were drawn on the T2∗ maps, covering the IVD. Based on T2 weighted MRI, discs were morphologically classified using the Pfirrmann score. Histological and macroscopic features were evaluated based on grading scales adapted for goat DD. Finally, GAG content was determined using colorimetric analysis (DMMB assay). Correlations between variables were analysed using Pearson correlation (r) coefficients (parametric data) or Spearman's rho (ρ) coefficients (non-parametric data). Results. The mean GAG content in the NP was 450 μg/mg dry weight (range 20–730 μg/mg dry weight) and the mean histological grade was 2.2 (range 0–6), corresponding with relatively mild disc degeneration. A linear positive correlation was observed between T2∗ and NP GAG content (r = 0.65, p < 0.001). T2∗ in the NP decreased linearly with increasing degeneration as assessed with macroscopic (ρ = 0.33, p < 0.05) and histological (ρ = −0.45, p < 0.05) grading, as well as with the Pfirrmann scoring system (ρ = −0.67, p < 0.001). Discussion. T2∗ mapping is a relatively new MRI technique which allows for measurements on a continuous scale, is acquired in less time than T2 mapping and minimises observer bias compared to grading systems. Although limited by a small sample size (n=48), this study showed a relatively good, linear correlation between T2∗ and GAG content in the NP, suggesting that T2∗ mapping may be an efficient and reliable tool for the objective assessment of proteoglycan content in early DD. Furthermore, with minor software modifications, it can be implemented on a standard 1.5 Tesla clinical MRI scanner. Future research should aim at optimizing the efficiency and user-friendliness of the T2∗ mapping protocol as well as yielding an even stronger correlation between T2∗ mapping and glycosaminoglycan content in human IVD tissue

In order to determine the usefulness of MRI in assessing autologous chondrocyte implantation (ACI) the first 57 patients (81 chondral lesions) with a 12-month review were evaluated clinically and with specialised MRI at three and 12 months. Improvement 12 months after operation was found subjectively (37.6 to 51.9) and in knee function levels (from 85% International Cartilage Repair Society (ICRS) III/IV to 61% I/II). The International Knee Documentation Committee (IKDC) scores showed an initial deterioration at three months (56% IKDC A/B) but marked improvement at 12 months (88% A/B). The MRI at three months showed 82% of patients with at least 50% defect fill, 59% with a normal or nearly normal signal at repair sites, 71% with a mild or no effusion and 80% with a mild or no underlying bone-marrow oedema. These improved at 12 months to 93%, 93%, 94% and 91%, respectively. The overall MR score at 12 months suggested production of normal or nearly normal cartilage in 82%, corresponding to a subjective improvement in 81% of patients and 88% IKDC A/B scores. Second-look surgery and biopsies in 15 patients (22 lesions) showed a moderate correlation of MRI with visual scoring; 70% of biopsies showed hyaline and hyaline-like cartilage. Thus, MRI at 12 months is a reasonable non-invasive means of assessment of ACI