MR imaging of the knee: findings in asymptomatic collegiate basketball players

Advanced MRI Approaches for Evaluating Common Lower Extremity Injuries in Basketball Players: Current and Emerging Techniques

Magnetic resonance imaging (MRI) can provide accurate and non-invasive diagnoses of lower extremity injuries in athletes. Sport-related injuries commonly occur in and around the knee and can affect the articular cartilage, patellar tendon, hamstring muscles, and bone. Sports medicine physicians utilize MRI to evaluate and diagnose injury, track recovery, estimate return to sport timelines, and assess the risk of recurrent injury. This article reviews the current literature and describes novel developments of quantitative MRI tools that can further advance our understanding of sports injury diagnosis, prevention, and treatment while minimizing injury risk and rehabilitation time. Innovative approaches for enhancing the early diagnosis and treatment of musculoskeletal injuries in basketball players span a spectrum of techniques. These encompass the utilization of T2, T1ρ, and T2* quantitative MRI, along with dGEMRIC and Na-MRI to assess articular cartilage injuries, 3D-Ultrashort echo time MRI for patellar tendon injuries, diffusion tensor imaging for acute myotendinous injuries, and sagittal short tau inversion recovery and axial long-axis T1-weighted, and 3D Cube sequences for bone stress imaging. Future studies should further refine and validate these MR-based quantitative techniques while exploring the lifelong cumulative impact of basketball on players' knees. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 2.

Ultrasound Changes in the Enthesis and Peri-enthesis Area of the Patellar and Achilles Tendons in Response to Physical Exercise: Comparison Between Healthy Subjects and Patients with Spondyloarthritis in Clinical Remission

RATIONALE AND OBJECTIVES

The goal of achieving clinical remission in patients with spondyloarthritis does not necessarily include the resolution of entheseal inflammation from a histological perspective. However, enthesis not clinically inflamed, under mechanical stress, may behave differently from healthy subjects considering the physiopathology of SpA. Our goal was to determine whether ultrasound changes in entheses differ between SpA patients in clinical remission and healthy subjects.

METHODS

SpA patients in clinical remission and matched healthy controls were recruited. At baseline, the following variables were measured on the dominant side by ultrasound: thickness of the distal patellar enthesis (hDP), the deep infrapatellar bursa (hDIB), the Achilles enthesis (hA), the preachilleal bursa (hPAB), effusion in the preachileal bursa (hePAB), and the presence of power Doppler signal in both enthesis. All measurements except hDP and hA were collected again after exercise (post-stress ultrasound).

RESULTS

30 patients and 30 controls were enrolled. In all subjects, hDIB, hPAB, and the preachileal bursa occupancy index increased significantly after the exercise. The increase was significantly greater in patients for all variables. At baseline, in patients, hyperemia was detected in one patellar tendon (3.3%) and in two Achilles tendons (6.7%). After exercise, the number of tendons with hyperemia increased to 11/30 (36.7%) and 12/30 (40%), respectively. Among controls, there was no detectable basal hyperemia, but after exercise, it was detected in 1/30 patellar tendons (3.3%) and 2/30 Achilles tendons (6.7%).

CONCLUSION

Exercise triggers a greater effusive and hyperemic synovial response in patients in remission than in healthy controls. These findings suggest that the definition of remission should also include an assessment of the synovial response to mechanical stress.

HIGHLIGHTS

Association Between Patellar Tendon Abnormality and Land-Jump Biomechanics in Male Collegiate Basketball Players During the Preseason

Background

Patellar tendinopathy is a degenerative condition that predominantly affects jumping athletes. Symptoms may be subtle or nonexistent at preseason, but structural abnormalities may be present. Assessing patellar tendon abnormality (PTA) through magnetic resonance imaging (MRI) and ultrasound (US) and classifying symptoms using the Victorian Institute for Sport Assessment-Patellar tendon (VISA-P) may provide useful insights if combined with biomechanics measurements.

Purpose

To (1) assess whether land-jump biomechanical patterns are associated with clinically pertinent PTA as seen on imaging and through VISA-P scores and (2) model the contributing risk and accuracy of biomechanics to classify PTA and symptomatic observations.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

A total of 26 National Collegiate Athletic Association Division I and II male basketball players (n = 52 limbs) were recruited during the preseason. We collected VISA-P scores, bilateral PTA through US and MRI morphology measurements, and bilateral 3-dimensional lower extremity kinematics and kinetics measurements from a land-jump test from an 18-inch-high (45.7-cm-high) box. Statistically, each limb was treated independently. The association of biomechanics with PTA and symptoms (VISA-P score <80) was tested with multivariate models and post hoc tests. Logistic regression modeled relative risk and accuracy of biomechanical variables to classify PTA and symptomatic limbs.

Results

There were 19 to 24 limbs with PTA depending on US and MRI measurements. Differences in hip and knee kinematic strategies and ground-reaction loads were associated with PTA and symptomatic limbs. Peak landing vertical ground-reaction force was significantly decreased (169 ± 26 vs 195 ± 29 %body weight; P = .001), and maximum hip flexion velocity was significantly increased (416 ± 74 vs 343 ± 94 deg/s; P = .005) in limbs with versus without PTA on imaging. Knee flexion at the initial contact was decreased in symptomatic versus healthy limbs (17°± 5° vs 21°± 5°, respectively; P = .045). Regression models classified PTA limbs and symptomatic limbs with 71.2% to 86.5% accuracy. Hip and knee maximum flexion velocity and vertical ground-reaction force variables were most common across models observing clinically pertinent PTA.

Conclusion

Our findings suggested that functional kinematic and kinetic biomechanical strategies at the hip and knee were associated with PTA, identified on imaging, and symptomatic limbs.

Value of Edema-like Marrow Signal Intensity in Diagnosis of Joint Pain: Radiologists' Perspective

Musculoskeletal pain is a significant contributor to disability. The mechanism and target of the treatment should be optimized by imaging, but currently no accepted gold standard exists to image pain. In addition to end-organ pathology, other mediators also contribute to nociception, such as angiogenesis, axonal extension, immunologic modulation, and central sensitization. Recent research indicates that local inflammation is a significant contributor to pain in the extremities; therefore, we focus here on edema-like marrow signal intensity (ELMSI). We examine both the relevance of ELMSI for pain and novel imaging techniques.

Foot and Ankle Bone Marrow Edema Assessment in Long Distance Runners

BACKGROUND

The clinical significance of foot and ankle bone marrow edema (BME) is poorly understood.

METHODS

Magnetic resonance imaging (MRI) and the visual analog scale (VAS) pain scores were collected for 17 runners who participated in the Twin Cities Marathon, immediately postmarathon and at a 6-week follow-up. Bone marrow edema lesions were classified using lesion frequency, anatomical location, and grading scale change to calculate a BME score for each affected bone. Spearman rank correlation coefficient test was used to identify a possible correlation between VAS and postmarathon BME. A paired Student t test was used to detect differences between total mileage ran 6 weeks postmarathon in participants with or without BME.

RESULTS

After completing the marathon, 8 BME lesions were identified in 5 participants (29.4%; 5/17), 3 were men, and 2 were women, with a mean age of 33.8 years (range: 24-52), and BMI of 22.9 ± 4. All lesions were resolved on 6-week follow-up imaging. VAS pain scores did not correlate with postmarathon BME. A significant difference in total miles logged over 6 weeks postmarathon could not be found among participants with and without BME.

CONCLUSION

Foot and ankle BME changes identified by MRI were not correlated to clinical symptoms and may resolve with self-directed activity in less time than other areas of the lower extremity.

LEVEL OF EVIDENCE

Level II, Prospective Cohort Study.

Multiparametric MRI of Knees in Collegiate Basketball Players: Associations With Morphological Abnormalities and Functional Deficits

Background

Rates of cartilage degeneration in asymptomatic elite basketball players are significantly higher compared with the general population due to excessive loads on the knee. Compositional quantitative magnetic resonance imaging (qMRI) techniques can identify local biochemical changes of macromolecules observed in cartilage degeneration.

Purpose/Hypothesis

The purpose of this study was to utilize multiparametric qMRI to (1) quantify how T1ρ and T2 relaxation times differ based on the presence of anatomic abnormalities and (2) correlate T1ρ and T2 with self-reported functional deficits. It was hypothesized that prolonged relaxation times will be associated with knees with MRI-graded abnormalities and knees belonging to basketball players with greater self-reported functional deficits.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

A total of 75 knees from National Collegiate Athletic Association Division I basketball players (40 female, 35 male) were included in this multicenter study. All players completed the Knee injury and Osteoarthritis Outcome Score (KOOS) and had bilateral knee MRI scans taken. T1ρ and T2 were calculated on a voxel-by-voxel basis. The cartilage surfaces were segmented into 6 compartments: lateral femoral condyle, lateral tibia, medial femoral condyle, medial tibia (MT), patella (PAT), and trochlea (TRO). Lesions from the MRI scans were graded for imaging abnormalities, and statistical parametric mapping was performed to study cross-sectional differences based on MRI scan grading of anatomic knee abnormalities. Pearson partial correlations between relaxation times and KOOS subscore values were computed, obtaining r value statistical parametric mappings and P value clusters.

Results

Knees without patellar tendinosis displayed significantly higher T1ρ in the PAT compared with those with patellar tendinosis (average percentage difference, 10.4%; P = .02). Significant prolongation of T1ρ was observed in the MT, TRO, and PAT of knees without compared with those with quadriceps tendinosis (average percentage difference, 12.7%, 13.3%, and 13.4%, respectively; P ≤ .05). A weak correlation was found between the KOOS-Symptoms subscale values and T1ρ/T2.

Conclusion

Certain tissues that bear the brunt of impact developed tendinosis but spared cartilage degeneration. Whereas participants reported minimal functional deficits, their high-impact activities resulted in structural damage that may lead to osteoarthritis after their collegiate careers.

Asymptomatic Bone Marrow Edema in Weight-bearing Bones in Athletes and Military Trainees: A Systematic Literature Review

Asymptomatic bone marrow edema (aBME) is a non-specific radiographic finding often found in athletes. Although aBME may represent the body's physiological response to training load, the etiology, MRI characteristics, and natural history of aBME remain unknown. To better characterize aBME in the lower extremities of military trainees and athletes. A systematic literature review in accordance with PRISMA guidelines was performed to identify primary research articles reporting on aBME in the lower extremities of athletes and military trainees. We identified 347 unique articles and after applying inclusion and exclusion criteria, 10 articles were included for qualitative synthesis. There were a total of 444 patients with an average age of 28.4±9.6 included. The most commonly used MRI sequences were proton-density with fat-saturation and T1-weighted imaging. The pattern of BME was inconsistently described, with various classification schemas used. The changes in aBME during longitudinal follow-up were dynamic and demonstrated both radiographic progression and regression. aBME is a highly prevalent and radiographically dynamic entity observed in high-level athletes and military trainees. Although follow-up was limited in the included studies, aBME may represent a natural, non-pathologic, reaction in response to specific biomechanical stressors.

Prevalence of Asymptomatic Talar Bone Marrow Edema in Professional Ballet Dancers: Preliminary Data From a 2-Year Prospective Study

Background

Compared with symptomatic bone marrow edema (BME) associated with stress fractures, asymptomatic BME seen on magnetic resonance imaging (MRI) is a phenomenon that has been described in high-level athletes and is thought to be related to bone adaptation to biomechanical loading unique to each sport. However, the prevalence, natural history, and management of these lesions remain poorly understood, particularly in dance, which places tremendous stress on the feet and ankles.

Purposes/Hypothesis

The purposes of this study were to (1) determine the prevalence of asymptomatic BME in the talus before the start of the performance season, (2) identify contributing demographic and training factors, and (3) compare the radiological evidence of talar BME with validated functional foot and ankle scores. We hypothesized that talar BME would be highly prevalent among asymptomatic professional dancers.

Study Design

Case series; Level of evidence, 4.

Methods

A total of 14 professional ballet dancers (6 female and 8 male; mean age, 24 years) were included in this 2-year prospective study. For each participant, we recorded complete medical and surgical history along with scores on the Foot and Ankle Ability Measure (FAAM) and the Foot and Ankle Disability Index. Bilateral foot and ankle 3.0-T MRI scans without contrast were completed before the start of the performance season and were evaluated for BME of the talus using the Fredericson criteria.

Results

Evidence of talar BME was seen in 15 of the 28 (54%) ankles examined and in 9 of 14 (64%) dancers. We found that 6 dancers demonstrated bilateral talar BME, 3 dancers demonstrated unilateral BME, and 5 dancers demonstrated no evidence of BME. The most common location of BME was the posterior talus, seen in 8 of 15 (53%) ankles. No statistically significant differences were noted in dancers with versus those without talar BME with regard to functional scores, demographic characteristics, or weekly training hours.

Conclusion

Asymptomatic talar BME was highly prevalent (64%) in professional ballet dancers and tended to occur posteriorly. Long-term clinical and radiographic follow-up is necessary to determine the natural history of these lesions.

Osteochondral Allograft Transplant for Combined Medial and Lateral Patellar Cartilage Lesions: The Osteochondral Wide Lesion (OWL) Technique

Symptomatic articular cartilage injuries are often seen in young active patients and athletes. Magnetic resonance imaging screening examinations have frequently identified such lesions in athletic patients. Patellofemoral chondral defects were previously identified as the most common knee cartilage lesion in high-level athletes. Chondral defects measuring 2 cm² or greater and complex cartilage defects involving bone loss are ideally replaced with fresh osteochondral allograft. We describe a technique indicated for patients with symptomatic and recurrent anterior knee pain associated with osteochondral patellar defects including the lateral and medial patellar facets. Patients who have undergone previous interventions, including membrane techniques, microfracture, or autologous chondral transplantation, without clinical benefit are also eligible to undergo osteochondral allograft transplantation for combined medial and lateral patellar cartilage lesions, that is, the osteochondral wide lesion (OWL) technique.

Changes in ultrasound imaging of joints, entheses, bursae and tendons 24 and 48 h after adjusted weight training

Background:

Joint effusion and enthesitis are common ultrasound findings in rheumatic diseases such as rheumatoid arthritis or spondyloarthritis. However, changes of joints and entheses were not only observed in patients but also in physically active individuals and athletes.

Objectives:

The purpose of this study was to evaluate joint, entheseal, bursal and tendon musculoskeletal ultrasound (MSUS) findings in large and medium joints of young healthy individuals after completing a standardised weight training.

Design:

This is a prospective cohort study.

Methods:

MSUS examinations of large- and medium-sized joints, and related entheseal sites, bursae and tendons were performed on young healthy individuals (ages 18–30 years). Before, 24 and 48 h after completing 1 h of standardised weight exercise, the subjects were evaluated by MSUS. The development of the MSUS findings and associated effects were examined using generalised linear mixed effects models.

Results:

In total, 51 healthy individuals (52.9% female) with a mean age of 23.7 (±2.5) years were enrolled. The results showed an increase in the number of individuals with at least one joint effusion from 37 (72.5%) before the weight training to 48 (94.1%) after 48 h. Entheses with pathologies were observed in 14 participants (27.5%) at baseline, increasing to 29 participants (56.9%) 48 h after the weight training. Biceps tendon sheath effusion was detected in 9 individuals (17.6%) prior to training, rising to 22 individuals (43.1%) after 48 h. A significant increase in the number of joints with effusion and abnormal entheses within 48 h after the weight training was indicated by the generalised linear mixed effects models.

Conclusion:

Within 48 h after the weight training session, a significant increase in the prevalence of joint effusion in large and medium joints and the prevalence of abnormal entheses was observed. As a result, when performing and interpreting an MSUS examination, the patient’s physical activities should be taken into account.

Rehabilitation, Restrictions, and Return to Sport After Cartilage Procedures

The ability to return to sport (RTS) after articular cartilage injury is of vital importance to athletes. Discussing the likelihood of returning to sport with patients is necessary, yet patients should be informed of the heterogeneous nature of the variables associated with successful RTS and the methodologic limitations behind current RTS rate estimates. Patient-specific factors affecting RTS are numerous and, in most cases, their isolated effect on RTS rates have yet to be examined and will remain difficult to do so. The purpose of this review is to discuss current RTS rates, explore factors leading to successful RTS, and examine the variability in physical therapy protocols after cartilage procedures, including microfracture, osteochondral allograft transplantation (OCA), autologous chondrocyte implantation (ACI), and meniscal allograft transplantation (MAT). The senior author’s postoperative protocols will also be presented, as with a discussion on using RTS as a metric of patient and procedural success. Overall, there is significant variation in reported RTS rates among procedures examined, and providers must continue managing patient expectations when discussing treatment options.

Reviewing Bone Marrow Edema in Athletes: A Difficult Diagnostic and Clinical Approach

Bone marrow edema (BME) is defined as an area of low signal intensity on T1-weighted (T1W) MRI images and associated with intermediate or high signal intensity findings on T2-weighted (T2W) MRI images. BME represents a typical imaging finding that characterizes common stress-related bone injuries of professional and amateur athletes. The etiology of stress-related injuries is influenced by numerous factors, including the initiation of a new sports activity or changes in an existing training protocol. The clinical significance of BME remains unclear. However, a correlation between the imaging pattern of BME, the clinical history of the patient and the type of sports activity practiced is essential for correct diagnosis and adequate therapeutic treatment. It is also important to clarify whether there is a specific threshold beyond which exercise can adversely affect the bone remodeling process, as the clinical picture may degenerate into the presence of BME, pain and, in the most severe cases, bone loss. In our review, we summarize the current knowledge on the etiopathogenesis and treatment options for BME and highlight the main aspects that make it difficult to formulate a correct diagnosis and establish an adequate therapeutic treatment.

Does Compression Sensory Axonopathy in the Proximal Tibia Contribute to Noncontact Anterior Cruciate Ligament Injury in a Causative Way?-A New Theory for the Injury Mechanism

Anterior cruciate ligament injury occurs when the ligament fibers are stretched, partially torn, or completely torn. The authors propose a new injury mechanism for non-contact anterior cruciate ligament injury of the knee. Accordingly, non-contact anterior cruciate ligament injury could not happen without the acute compression microinjury of the entrapped peripheral proprioceptive sensory axons of the proximal tibia. This would occur under an acute stress response when concomitant microcracks-fractures in the proximal tibia evolve due to the same excessive and repetitive compression forces. The primary damage may occur during eccentric contractions of the acceleration and deceleration moments of strenuous or unaccustomed fatiguing exercise bouts. This primary damage is suggested to be an acute compression/crush axonopathy of the proprioceptive sensory neurons in the proximal tibia. As a result, impaired proprioception could lead to injury of the anterior cruciate ligament as a secondary damage, which is suggested to occur during the deceleration phase. Elevated prostaglandin E2, nitric oxide and glutamate may have a critical neuro-modulatory role in the damage signaling in this dichotomous neuronal injury hypothesis that could lead to mechano-energetic failure, lesion and a cascade of inflammatory events. The presynaptic modulation of the primary sensory axons by the fatigued and microdamaged proprioceptive sensory fibers in the proximal tibia induces the activation of N-methyl-D-aspartate receptors in the dorsal horn of the spinal cord, through a process that could have long term relevance due to its contribution to synaptic plasticity. Luteinizing hormone, through interleukin-1β, stimulates the nerve growth factor-tropomyosin receptor kinase A axis in the ovarian cells and promotes tropomyosin receptor kinase A and nerve growth factor gene expression and prostaglandin E2 release. This luteinizing hormone induced mechanism could further elevate prostaglandin E2 in excess of the levels generated by osteocytes, due to mechanical stress during strenuous athletic moments in the pre-ovulatory phase. This may explain why non-contact anterior cruciate ligament injury is at least three-times more prevalent among female athletes.

Physical Activity and Investigation With Magnetic Resonance Imaging Partly Explain Variability in the Prevalence of Patellar Tendon Abnormalities: A Systematic Review With Meta-analysis of Imaging Studies in Asymptomatic Individuals

OBJECTIVE

To estimate the pooled prevalence of, and factors associated with, the presence of patellar tendon abnormalities observed on imaging in people without symptoms.

DESIGN

Systematic review with stratified meta-analysis and meta-regression.

LITERATURE SEARCH

We searched Embase, Scopus, MEDLINE, CINAHL, SPORTDiscus, and Web of Science from 1980 to August 2020.

STUDY SELECTION CRITERIA

We included studies that reported the prevalence of asymptomatic patellar tendon abnormalities on imaging. We excluded studies of participants with current tendon pain, a history of tendon pain, or other systemic conditions.

DATA SYNTHESIS

Stratification and meta-regression of studies based on study-level descriptive statistics (mean age, body mass index, proportion of female participants, physical activity participation, imaging modality) were performed using a random-effects model to account for between-study heterogeneity. Risk of bias was assessed using the modified Newcastle-Ottawa scale.

RESULTS

Meta-analysis of 64 studies (7125 limbs from 4616 participants) found significant between-study heterogeneity (I²≥90%, P<.01), which precluded a summary prevalence estimate. Heterogeneity was partially explained by studies that included participants who were physically active and studies that assessed tendon abnormalities using magnetic resonance imaging compared to ultrasound (P<.05). Mean age, body mass index, proportion of female participants, and sample size did not explain the remaining heterogeneity.

CONCLUSION

There was substantial variability in the reported prevalence of asymptomatic patellar tendon abnormalities. A clear and valid method is needed to assess and report the presence of patellar tendon abnormalities to increase research capacity and establish the clinical value of imaging the patellar tendon. J Orthop Sports Phys Ther 2021;51(5):216-231. Epub 28 Mar 2021. doi:10.2519/jospt.2021.10054.

Effects of the Competitive Season and Off-Season on Knee Articular Cartilage in Collegiate Basketball Players Using Quantitative MRI: A Multicenter Study

BACKGROUND

Injuries to the articular cartilage in the knee are common in jumping athletes, particularly high-level basketball players. Unfortunately, these are often diagnosed at a late stage of the disease process, after tissue loss has already occurred.

PURPOSE/HYPOTHESIS

To evaluate longitudinal changes in knee articular cartilage and knee function in National Collegiate Athletic Association (NCAA) basketball players and their evolution over the competitive season and off-season.

STUDY TYPE

Longitudinal, multisite cohort study.

POPULATION

Thirty-two NCAA Division 1 athletes: 22 basketball players and 10 swimmers.

FIELD STRENGTH/SEQUENCE

Bilateral magnetic resonance imaging (MRI) using a combined T_1ρ and T₂ magnetization-prepared angle-modulated portioned k-space spoiled gradient-echo snapshots (MAPSS) sequence at 3T.

ASSESSMENT

We calculated T₂ and T_1ρ relaxation times to compare compositional cartilage changes between three timepoints: preseason 1, postseason 1, and preseason 2. Knee Osteoarthritis Outcome Scores (KOOS) were used to assess knee health.

STATISTICAL TESTS

One-way variance model hypothesis test, general linear model, and chi-squared test.

RESULTS

In the femoral articular cartilage of all athletes, we saw a global decrease in T₂ and T_1ρ relaxation times during the competitive season (all P < 0.05) and an increase in T₂ and T_1ρ relaxation times during the off-season (all P < 0.05). In the basketball players' femoral cartilage, the anterior and central compartments respectively had the highest T₂ and T_1ρ relaxation times following the competitive season and off-season. The basketball players had significantly lower KOOS measures in every domain compared with the swimmers: Pain (P < 0.05), Symptoms (P < 0.05), Function in Daily Living (P < 0.05), Function in Sport/Recreation (P < 0.05), and Quality of Life (P < 0.05).

CONCLUSION

Our results indicate that T₂ and T_1ρ MRI can detect significant seasonal changes in the articular cartilage of basketball players and that there are regional differences in the articular cartilage that are indicative of basketball-specific stress on the femoral cartilage. This study demonstrates the potential of quantitative MRI to monitor global and regional cartilage health in athletes at risk of developing cartilage problems.

LEVEL OF EVIDENCE

2 Technical Efficacy Stage: 2.

Correlation of T2* relaxation times of the retropatellar cartilage with tibial tuberosity-trochlea groove distance in professional soccer players

The tibial tuberosity–trochlear groove (TT–TG) distance is a radiographic measurement that is used to quantify malalignment of the patellofemoral joint (PFJ) in cross-sectional imaging. There is an ongoing debate about the impact of the TT–TG-distance on lateral patellar instability and the initiating of cartilage degeneration. In this prospective study, the association of T2* relaxation times and TT–TG distances in professional soccer players was analyzed. 36 knees of 18 professional soccer players (age: 21 ± 2.8 years) were evaluated. Participants underwent knee MRI at 3 T. For qualitative image analysis, fat-saturated 2D PD-weighted Fast Spin Echo (FSE) and T1-weighted FSE sequences were used. For quantitative analysis, T2* measurements in 3D data acquisitions were performed. In a qualitative analysis there was no structural cartilage damage and no abnormalities of the patellar and trochlea shape. The highest T2* values (26.7 ± 5.9 ms) were observed in the central compartment of the patella. The mean TT–TG distance was 10 ± 4 mm (range 3–20 mm). There was no significant correlation between TT–TG distance and T2* relaxation times in all three compartments of the retropatellar cartilage. Our study shows that so long as patellar and trochlear morphology is normal, TT–TG distance alone does not affect the tissue structure of the retropatellar cartilage in professional soccer players.

Remarkably high prevalence of overuse-related knee complaints and MRI abnormalities in youth competitive alpine skiers: a descriptive investigation in 108 athletes aged 13-15 years

Background/aim

Competitive alpine skiing is known to be associated with a high risk of traumatic knee injuries. However, little is known about the exact prevalence of knee overuse injuries and their associations with structural changes, particularly in youth skiers. Accordingly, the aim of the present study was to describe the overuse-related knee complaints and MRI abnormalities in a cohort of youth skiers around the growth spurt.

Methods

108 youth competitive alpine skiers aged 13–15 years were examined using an MRI of both knees, an interview on existing knee complaints and a physical examination. As a common baseline for these assessments, skiers were prospectively monitored by the use of the Oslo Sports Trauma Research Centre questionnaire on health problems over a period of 12 months preceding the major investigations.

Results

88.0% of the youth skiers showed at least one MRI abnormality in the knees. The most frequent findings were distal femoral cortical irregularities (63%), focal periphyseal oedema (FOPE) zones (25.0%) and cartilage lesions (18.5%). 47.2% of all skiers suffered from at least one overuse-related knee complaint during the 12 months preceding the MRI examination, mostly at the distal and proximal patellar tendon. However, despite a certain association with corresponding MRI abnormalities, the sensitivity of an MRI-based detection of such complaints was strongly limited.

Conclusion

Youth competitive alpine skiers suffer from a remarkably large number of knee overuse injuries. Accordingly, an effective prevention strategy should include a systematic screening of clinical complaints, ideally already starting around the growth spurt.

Medical imaging and diagnosis of subpatellar vertebrae based on improved Laplacian image enhancement algorithm

OBJECTIVE

Nowadays, arthroscopy is widely applied to the treatment of joint diseases. The experimental trials were designed to determine whether the infrapatellar plica was symptomatic or not, and to appraise the medical effects of these patients who underwent arthroscopic treatment. An improved Laplacian image enhancement algorithm is added to the experiment. The medical image of the Subpatellar vertebral body under arthroscope is processed by the algorithm. The processed image is compared with the original image, and the advantages and disadvantages of the improved Laplacian image enhancement algorithm are analyzed.

METHODS

Retrospective Medical trial design was executed in our study. In addition, X-ray film and magnetic resonance imaging (MRI) were included in the study. Visual Analogue Scale (VAS) and Lysholm Score were carried out. Arthroscopy results, MRI findings, and Medical features were researched and analyzed carefully. Then we use the improved Laplacian image enhancement algorithm to process the image, which makes the image more convenient for analysis and improves the diagnostic accuracy.

RESULTS

Some of the experimental protomedical images are not clear enough, and the details and textures are difficult to judge, which hinders the diagnosis. After the improved Laplacian algorithm processing, the image effect has been significantly improved. From the image we get the result, although the wound healed after surgery, some patients have existence of transient swelling in recovery process but no effusion. The pain of all patients knee was sharply relieved and the function was improved. All patients' conditions were most satisfactory.

CONCLUSION

The findings in this study demonstrate a significant reduction in knee pain and improvement in function by releasing and removal of the symptomatic infrapatellar plica under arthroscopic surgery. The image processed by the improved Laplacian image enhancement algorithm can effectively retain the image details, which is conducive to diagnosis and improve the diagnostic accuracy.

Bone Marrow Oedema in the Knees of Asymptomatic High-Level Athletes: Prevalence and Associated Factors

BACKGROUND

Bone marrow oedema (BMO), seen on magnetic resonance imaging, can be associated with various injuries to the knee but may also occur in asymptomatic athletes. The prevalence and causal factors for these observations are not well understood. The aim of this study was to determine the prevalence of BMO in asymptomatic knees of athletes, competing at a high level, and to investigate the associated factors.

MATERIALS AND METHODS

Twenty-five asymptomatic university athletes, competing at regional to international level, were recruited. Bilateral knee magnetic resonance imaging was performed in each athlete (total 50 knee scans) at the end of their competitive season. Imaging studies were reported independently by two experienced consultant musculoskeletal radiologists.

RESULTS

There was almost perfect agreement between reporters for diagnosis of BMO (κ = 0.896). Seven participants (28%) were found to have BMO (six in one knee and one bilaterally). The amount of time spent training, during the season, was significantly associated with the appearance of BMO (p < 0.05).

CONCLUSION

The occurrence of BMO in asymptomatic knees of athletes is common (occurring in over one-quarter of knees) and may be associated with training intensity. This should be considered when treating athletes and deciding upon appropriate treatment plans.

Prevalence of abnormal findings in 230 knees of asymptomatic adults using 3.0 T MRI

OBJECTIVE

To identify abnormalities in asymptomatic sedentary individuals using 3.0 Tesla high-resolution MRI.

MATERIALS AND METHODS

The cohort comprised of 230 knees of 115 uninjured sedentary adults (51 males, 64 females; median age: 44 years). All participants had bilateral knee 3.0 T MRIs. Two senior musculoskeletal radiologists graded all intraarticular knee structures using validated scoring systems. Participants completed Knee Injury and Osteoarthritis Outcome Score questionnaires at the time of the MRI scan.

RESULTS

MRI showed abnormalities in the majority (97%) of knees. Thirty percent knees had meniscal tears: horizontal (23%), complex (3%), vertical (2%), radial (2%) and bucket handle (1%). Cartilage and bone marrow abnormalities were prevalent at the patellofemoral joint (57% knees and 48% knees, respectively). Moderate and severe cartilage lesions were common, in 19% and 31% knees, respectively, while moderate and severe bone marrow oedema in 19% and 31% knees, respectively. Moderate-intensity lesion in tendons was found in 21% knees and high-grade tendonitis in 6% knees-the patellar (11% and 2%, respectively) and quadriceps (7% and 2%, respectively) tendons being most affected. Three percent partial ligamentous ruptures were found, especially of the anterior cruciate ligament (2%).

CONCLUSION

Nearly all knees of asymptomatic adults showed abnormalities in at least one knee structure on MRI. Meniscal tears, cartilage and bone marrow lesions of the patellofemoral joint were the most common pathological findings. Bucket handle and complex meniscal tears were reported for the first time in asymptomatic knees.

It's a thin line: development and validation of Dixon MRI-based semi-quantitative assessment of stress-related bone marrow edema in the wrists of young gymnasts and non-gymnasts

Purpose

To assess reliability and clinical utility of evaluating stress-related metaphyseal water distribution using a semi-quantitative Dixon MRI-based method for early diagnosis of physeal stress injuries in adolescent gymnasts.

Methods

Twenty-four gymnasts with clinically suspected overuse injury of the distal radial physis, 18 asymptomatic gymnasts, and 24 non-gymnast controls aged 12 ± 1.5 years prospectively underwent hand radiographs and 3T MRI of the wrist including coronal T1-weighted and T2-weighted Dixon sequences. Two raters measured metaphyseal water signal fraction in 13 radial and ulnar regions of interest (ROI). Inter- and intrarater reliability, interslice (between 3 middle radial slices), and inter-ROI (between 3 ROIs on same level) reliability were assessed using intraclass correlation coefficients (ICC). Water signal fractions and their within-person ratios in distal versus most proximal ROIs were compared between groups using one-way analysis of variance.

Results

Inter- and intrarater ICCs were 0.79–0.99 and 0.94–1.0 for T1-weighted, and 0.88–1.0 and 0.88–1.0 for T2-weighted Dixon. Interslice and inter-ROI ICCs were 0.55–0.94 and 0.95–0.97 for T1-weighted, and 0.70–0.96 and 0.96–0.97 for T2-weighted Dixon. Metaphyseal water signal fraction in symptomatic gymnasts was higher in six distal ROIs compared with asymptomatic gymnasts and in nine ROIs compared with non-gymnasts (p < 0.05). Metaphyseal water score (ratio of distal versus most proximal ROIs) was 1.61 in symptomatic gymnasts and 1.35 in asymptomatic gymnasts on T2-weighted Dixon (p < 0.05).

Conclusion

Semi-quantitative Dixon MRI-based water signal fraction assessment has good to excellent reproducibility and shows increased metaphyseal water scores in symptomatic gymnasts compared with asymptomatic gymnastic peers.

Key Points

• The proposed Dixon MRI-based semi-quantitative method for assessment of metaphyseal bone marrow water content is reliable, with off-the-shelf availability and short scan times.

• The metaphyseal water score allows comparisons between gymnasts using a within-person reference area for unaffected metaphyseal bone.

• As metaphyseal water score was increased in symptomatic gymnasts compared with asymptomatic gymnasts, this semi-quantitative method can potentially be used as an indicator of bone marrow edema in the early diagnosis of gymnastic physeal stress injury.

Electronic supplementary material

The online version of this article (10.1007/s00330-019-06446-8) contains supplementary material, which is available to authorized users.

Increased signal in the proximal patellar tendon: normal or pathologic?

OBJECTIVE

To determine the clinical significance of T2 signal hyperintensity in the proximal patellar tendon seen on MRI of the knee.

MATERIALS AND METHODS

MRIs of 100 patients who underwent MRI of the knee between 1 May 2018 and 15 July 2018 were retrospectively evaluated. All examinations were performed on 3-Tesla MRI scanners with a dedicated knee coil and in accordance with our institution's standard knee MRI protocol. The presence of increased T2 signal was assessed on both sagittal and axial T2-weighted fat-saturated images. The amount of increased signal in the proximal patellar tendon on T2-weighted images was characterized as: none, mild, moderate, or severe. A corresponding chart review of the referring physicians' notes was performed to determine the presence of clinical symptoms of patellar tendinopathy. Patellar tendinopathy was considered present if the clinical notes described tenderness on palpation of the inferior patellar pole, infrapatellar tenderness, or patellar tendinosis/tendinitis.

RESULTS

The majority (66%) of knee MRIs demonstrated the presence of increased T2 signal in the proximal patellar tendon. Only 4.5% of these patients had associated clinical findings of patellar tendinopathy.

CONCLUSION

Although increased T2 signal in the proximal patellar tendon is a common finding, only in rare cases are there associated clinical symptoms. Thus, increased T2 signal in the proximal patellar tendon may not be a pathological finding in the absence of clinical findings of patellar tendinopathy.

Platelet-Rich Plasma for Patellar Tendinopathy: A Randomized Controlled Trial of Leukocyte-Rich PRP or Leukocyte-Poor PRP Versus Saline

BACKGROUND

A small number of randomized controlled trials have found ultrasound-guided injection of platelet-rich plasma (PRP) to be no more effective than saline for several tendinopathies; limited information exists for patellar tendinopathy. In addition, different PRP formulations that produce varying concentrations of leukocytes have not been directly compared for patellar tendinopathy.

PURPOSE/HYPOTHESIS

To determine if a single ultrasound-guided PRP injection, either leukocyte-rich PRP (LR-PRP) or leukocyte-poor PRP (LP-PRP), was superior to saline injection for the treatment of patellar tendinopathy. The null hypothesis was that no treatment would be superior to another for the treatment of patellar tendinopathy.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Athletes with patellar tendinopathy for ≥6 months (Blazina stage IIIB) were assessed for eligibility in a multisite single-blind controlled trial. There were 3 injection arms: LR-PRP, LP-PRP, and saline. Patients received a single ultrasound-guided injection, followed by 6 weeks of supervised rehabilitation (heavy slow resistance training, concentric and eccentric, 3 times per week). Outcome measures-Victorian Institute of Sport Assessment (patellar; VISA-P), pain during activity, and global rating of change-were assessed at 6 and 12 weeks and 6 and 12 months. VISA-P score at 12 weeks was the primary outcome. Fifty-seven patients (19 in each group) were included in an intention-to-treat analysis. Secondary outcome measures included pain during activity and patients' global rating of change.

RESULTS

Study retention was 93% at 12 weeks and 79% after 1 year. There was no significant difference in mean change in VISA-P score, pain, or global rating of change among the 3 treatment groups at 12 weeks or any other time point. After 1 year, the mean (SD) outcomes for the LR-PRP, LP-PRP, and saline groups were as follows, respectively: VISA-P-58 (29), 71 (20), and 80 (18); pain-4.0 (2.4), 2.4 (2.3), and 2.0 (1.9); global rating of change-4.7 (1.6), 5.6 (1.0), and 5.7 (1.2) ( P > .05 for all outcomes).

CONCLUSION

Combined with an exercise-based rehabilitation program, a single injection of LR-PRP or LP-PRP was no more effective than saline for the improvement of patellar tendinopathy symptoms.

REGISTRATION

NCT02116946 (ClinicalTrials.gov identifier).

MRI-Detected Sports-Related Knee Injuries and Abnormalities at the Rio de Janeiro 2016 Summer Olympic Games

OBJECTIVE

The purpose of this article is to describe knee abnormalities and the occurrence of MRI-detected sports-related knee abnormalities by evaluating MRI examinations performed during the Rio de Janeiro Olympic Games held in August 2016.

CONCLUSION

There were 11,274 athletes at the Rio 2016 Olympic Games, and 113 of them underwent at least one knee MRI in the Olympic Village. Cartilage abnormalities, followed by meniscal tears and ligament sprains, were the most frequent abnormalities.

Prevalence of knee osteoarthritis features on magnetic resonance imaging in asymptomatic uninjured adults: a systematic review and meta-analysis

Background

Knee MRI is increasingly used to inform clinical management. Features associated with osteoarthritis are often present in asymptomatic uninjured knees; however, the estimated prevalence varies substantially between studies. We performed a systematic review with meta-analysis to provide summary estimates of the prevalence of MRI features of osteoarthritis in asymptomatic uninjured knees.

Methods

We searched six electronic databases for studies reporting MRI osteoarthritis feature prevalence (ie, cartilage defects, meniscal tears, bone marrow lesions and osteophytes) in asymptomatic uninjured knees. Summary estimates were calculated using random-effects meta-analysis (and stratified by mean age: <40 vs ≥40 years). Meta-regression explored heterogeneity.

Results

We included 63 studies (5397 knees of 4751 adults). The overall pooled prevalence of cartilage defects was 24% (95% CI 15% to 34%) and meniscal tears was 10% (7% to 13%), with significantly higher prevalence with age: cartilage defect <40 years 11% (6%to 17%) and ≥40 years 43% (29% to 57%); meniscal tear <40 years 4% (2% to 7%) and ≥40 years 19% (13% to 26%). The overall pooled estimate of bone marrow lesions and osteophytes was 18% (12% to 24%) and 25% (14% to 38%), respectively, with prevalence of osteophytes (but not bone marrow lesions) increasing with age. Significant associations were found between prevalence estimates and MRI sequences used, physical activity, radiographic osteoarthritis and risk of bias.

Conclusions

Summary estimates of MRI osteoarthritis feature prevalence among asymptomatic uninjured knees were 4%–14% in adults aged <40 years to 19%–43% in adults ≥40 years. These imaging findings should be interpreted in the context of clinical presentations and considered in clinical decision-making.

Evaluation of Knees in Asymptomatic Amateur Ice Hockey Players Using 3.0-T Magnetic Resonance Imaging: A Case-Control Study

Background:

Research on the changes to knee structures in asymptomatic amateur ice hockey players (AAIHPs) has been limited. We aimed to assess the performance of the knees in AAIHPs using 3.0-T magnetic resonance imaging (MRI).

Methods:

A total of 71 asymptomatic knees (32 AAIHPs and 39 age- and sex-matched controls) were imaged using a 3.0-T MRI scanner at the Affiliated Zhongshan Hospital of Dalian University in April 2017. Two experienced musculoskeletal radiologists were blinded to assess all MRI findings, including bursae around the knee, bone marrow edema (BME), meniscal signal changes, and articular cartilage and ligament damage. Any disagreements were resolved by a third professor of musculoskeletal radiology. Categorical variables were compared using the Chi-square test and continuous variables using the Student's t-test or Mann-Whitney U-test.

Results:

The most common finding was fluid-filled bursae surrounding the knee. In the AAIHP group, which totaled 32 knees and 416 bursae, 155 (37%) fluid-filled bursae were present. In the control group, there were a total of 39 knees and 507 bursae, and 91 (18%) fluid-filled bursae were present. There was a significant difference in the number of fluid-filled bursae between the two groups (P < 0.05). However, in AAIHPs, the prevalence of meniscal signal changes (16 knees, 50%) was higher than in the control group (2 knees, 5%; P < 0.001). Importantly, 15 of the 19 were grade II signals. Other changes were only found in AAIHPs. Articular cartilage lesions were detected in 47% of their knees, predominantly at the patellofemoral joint, and BME was found in 34% of their knees.

Conclusion:

The MRI findings of knees in AAIHPs mainly manifested as self-protection reaction, and proper ice hockey exercise could be advocated.

Systematic assessment of the growth plates of the wrist in young gymnasts: development and validation of the Amsterdam MRI assessment of the Physis (AMPHYS) protocol

Objectives

To develop and validate a protocol for MRI assessment of the distal radial and ulnar periphyseal area in gymnasts and non-gymnasts.

Methods

Twenty-four gymnasts with wrist pain, 18 asymptomatic gymnasts and 24 non-gymnastic controls (33 girls) underwent MRI of the wrist on a 3T scanner. Sequences included coronal proton density-weighted images with and without fat saturation, and three-dimensional water-selective cartilage scan and T2 Dixon series. Skeletal age was determined using hand radiographs. Three experienced musculoskeletal radiologists established a checklist of possible (peri)physeal abnormalities based on literature and clinical experience. Five other musculoskeletal radiologists and residents evaluated 30 MRI scans (10 from each group) using this checklist and reliability was determined using the intraclass correlation coefficient (ICC) and Fleiss' kappa. A final evaluation protocol was established containing only items with fair to excellent reliability.

Results

Twenty-seven items were assessed for reliability. Intra-rater and inter-rater agreement was good to excellent (respective ICCs 0.60-0.91 and 0.60-0.78) for four epiphyseal bone marrow oedema-related items, physeal signal intensity, metaphyseal junction and depth of metaphyseal intrusions. For physeal thickness, thickness compared with proximal physis of first metacarpal, metaphyseal intrusions, physeal connection of intrusions and metaphyseal bone marrow signal intensity, intra-rater agreement was fair to excellent (ICC/kappa 0.55-0.85) and inter-rater agreement was fair (ICC/kappa 0.41-0.59). Twelve items were included in the final protocol.

Conclusion

The Amsterdam MRI assessment of the Physis protocol facilitates patient-friendly and reliable assessment of the (peri)physeal area in the radius and ulna.

The Prevalence of Meniscal Pathology in Asymptomatic Athletes

BACKGROUND

Meniscal pathology is a commonly seen orthopedic condition that can affect a wide age range of patients. Athletes subject their menisci to an increased amount of stress during their careers and may increase their risk of meniscal pathology.

OBJECTIVE

The purpose of this systematic review is to evaluate the prevalence of isolated meniscal pathology in asymptomatic athletes.

METHODS

A systematic review was undertaken to determine the prevalence of meniscal pathology in asymptomatic athletes. A search of multiple databases was conducted. Recreational and higher-level athletes were included. Fourteen articles including 295 athletes (208 male, 87 female) were identified for inclusion (age range 14-66 years, mean 31.2 years). Meniscal pathology was visualized with magnetic resonance imaging and graded on a 1-4 scale (grades 1 and 2 indicating intrasubstance damage, grades 3 and 4 indicating a tear).

RESULTS

There was an overall prevalence of 27.2 % (105/386) of knees with intrasubstance meniscal damage (grades 1 and 2), and 3.9 % (15/386) of knees with a tear (grades 3 and 4). When athletes were split into those who participate in pivoting sports versus non-pivoting sports, pivoting athletes showed an overall prevalence of 15.3 % (31/202) of knees with intrasubstance meniscal pathology and 2.5 % (5/202) of knees with a tear. Non-pivoting athletes showed a prevalence of 54.5 % (61/112) of knees with intrasubstance meniscal pathology and 5.4 % (6/112) of knees with a tear.

CONCLUSION

The overall prevalence of isolated meniscal pathology in asymptomatic athletes was 31.1 % (27.2 % with intrasubstance meniscal damage and 3.9 % with a meniscal tear). More studies of age-comparable, non-athletic populations are necessary for direct comparison with these groups.

Aetiology and pathogenesis of bone marrow lesions and osteonecrosis of the knee

Bone marrow lesions (BML) of the knee are a frequent MRI finding, present in many different pathologies including trauma, post-cartilage surgery, osteoarthritis, transient BML syndromes, spontaneous insufficiency fractures, and true osteonecrosis.

Osteonecrosis (ON) is in turn divided into spontaneous osteonecrosis (SONK), which is considered to be correlated to subchondral insufficiency fractures (SIFK), and avascular necrosis (AVN) which is mainly ascribable to ischaemic events.

Every condition has a MRI pattern, a different clinical presentation, and specific histological features which are important in the differential diagnosis.

The current evidence supports an overall correlation between BML and patient symptoms, although literature findings are variable, and very little is known about the natural history and the progression of these lesions.

A full understanding of BML will be mandatory in the future to better address the different pathologies and develop appropriately-targeted treatments.

Cite this article: Marcacci M, Andriolo L, Kon E, Shabshin N, Filardo G. Aetiology and pathogenesis of bone marrow lesions and osteonecrosis of the knee. EFORT Open Rev 2016;1:219-224. DOI: 10.1302/2058-5241.1.000044.

Are Ultrasound Findings Similar in Patients with Axial Spondyloarthritis and in Athlete Entheses?

OBJECTIVE

Enthesitis is the spondyloarthritis (SpA) landmark, but can also be seen after entheses overuse, such as during intensive sport.

METHODS

We aimed to compare entheses ultrasound (US) findings in a prospective cross-sectional study of 30 axial SpA cases, 30 athletes, and 29 controls.

RESULTS

Mean (SD) MAdrid Sonographic Enthesis Index (MASEI) score was 26.3 (13), 12.2 (7), and 10.4 (6) in patients with SpA, athletes, and non-athlete control groups, respectively (p < 0.0001).

CONCLUSION

The MASEI score was significantly higher in patients with SpA compared with healthy controls, athletes, and non-athletes, and can be of value to distinguish SpA from healthy subjects, whatever their physical activity.

MRI findings of knee abnormalities in adolescent and adult volleyball players

Background

To longitudinally and cross-sectionally evaluate knee abnormalities by sex and age in adolescent and adult volleyball athletes over 2 years using magnetic resonance imaging (MRI).

Methods

Thirty-six high-level volleyball athletes (18 adolescents: 56% female, mean age 16.0 ± 0.8 years; and 18 adults: 50% female, mean age 46.8 ± 5.1 years) were imaged by MRI at BL and at 2-year follow-up (FU). Prevalence and severity of cartilage lesions, subarticular bone marrow lesions (BMLs), subarticular cysts, osteophytes, and ligament and meniscus integrity were evaluated by sex and by age cohort (adolescents and adults) using the whole-organ MRI score (WORMS).

Results

There were no significant longitudinal changes in any of the features within any of the sex or age groups. No significant differences were found in overall prevalence or severity of any of the features between males and females, although at FU, males had a significantly higher prevalence of osteophytes in the medial femorotibial joint (MFTJ) than females (p=0.044). Compared to adolescents, adult volleyball players had a significantly greater prevalence and severity of cartilage lesions (p<0.001 for both), BMLs (p=0.0153 and p=0.005), and osteophytes (p≤0.003 and p<0.001), and more severe meniscal lesions (p≤0.021).

Conclusion

We found significant differences in the prevalence and severity of knee abnormalities between adolescent and adult volleyball players, but no overall differences by sex. These findings lay the groundwork for further investigations with larger cohorts and longer FU times to determine whether or not these knee abnormalities are associated with the development of OA.

Common Mistakes and Pitfalls in Magnetic Resonance Imaging of the Knee

This pictorial review presents an overview of common interpretation errors and pitfalls in magnetic resonance imaging (MRI) of the knee. Instead of being exhaustive, we will emphasize those pitfalls that are most commonly encountered by young residents or less experienced radiologists.

Magnetic Resonance Imaging of Asymptomatic Knees in Collegiate Basketball Players: The Effect of One Season of Play

OBJECTIVE

To determine the prevalence of abnormal structural findings using 3.0-T magnetic resonance imaging (MRI) in the asymptomatic knees of male and female collegiate basketball players before and after a season of high-intensity basketball.

DESIGN

Institutional review board-approved prospective case series.

PARTICIPANTS

Asymptomatic knees of 24 NCAA Division I collegiate basketball players (12 male, 12 female) were imaged using a 3.0-T MRI scanner before and after the end of the competitive season. Three subjects did not undergo scanning after the season.

MAIN OUTCOME MEASURES

Images were evaluated for prepatellar bursitis, fat pad edema, patellar and quadriceps tendinopathy, bone marrow edema, and articular cartilage and meniscal injury.

RESULTS

Every knee imaged had at least 1 structural abnormality both preseason and postseason. A high preseason and postseason prevalence of fat pad edema (75% and 81%), patellar tendinopathy (83% and 90%), and quadriceps tendinopathy (75% and 90%) was seen. Intrameniscal signal change was observed in 50% preseason knees and 62% of postseason knees, but no discrete tears were found. Bone marrow edema was seen in 75% and 86% of knees in the preseason and postseason, respectively. Cartilage findings were observed in 71% and 81% of knees in the preseason and postseason, respectively. The cartilage injury score increased significantly in the postseason compared with the preseason (P = 0.0009).

CONCLUSIONS

A high prevalence of abnormal knee MRI findings was observed in a population of asymptomatic young elite athletes. These preliminary data suggest that high-intensity basketball may have potentially deleterious effects on articular cartilage.

Comparison of T2* relaxation times of articular cartilage of the knee in elite professional football players and age-and BMI-matched amateur athletes

OBJECTIVE

Recent investigation has underlined the potential of quantitative MR imaging to be used as a complementary tool for the diagnosis of cartilage degeneration at an early state. The presented study analyses T2* relaxation times of articular cartilage of the knee in professional athletes and compares the results to age- and BMI (Body Mass Index)-matched healthy amateur athletes.

MATERIALS AND METHODS

22 professional football players and 22 age- and BMI-matched individuals were underwent knee Magnetic Resonance Imaging (MRI) at 3T including qualitative and quantitative analysis. Qualitative analysis included e.g. meniscal tears, joint effusion and bone edema. For quantitative analysis T2* (22 ET: 4.6-53.6ms) measurements in 3D data acquisition were performed. Deep and superficial layers of 22 predefined cartilage segments were analysed. All data sets were postprocessed using a dedicated software tool. Statistical analysis included Student t-test, confidence intervals and a random effects model.

RESULTS

In both groups, T2* relaxation times were significantly higher in the superficial compared to the deep layers (p<0.001). Professional athletes had significantly higher relaxation times in eight superficial and three deep cartilage layers in the predefined cartilage segments (p<0.05). Highly significant differences were found in the weight-bearing segments of the lateral superficial femoral condyle (p<0.001).

CONCLUSION

Elevated T2* values in cartilage layers of professional football players compared to amateur athletes were noted. The effects seem to predominate in superficial cartilage layers.

Structural Abnormalities on Magnetic Resonance Imaging in Patients With Patellofemoral Pain: A Cross-sectional Case-Control Study

BACKGROUND

Structural abnormalities of the patellofemoral joint might play a role in the pathogenesis of patellofemoral pain (PFP), a common knee problem among young and physically active individuals. No previous study has investigated if PFP is associated with structural abnormalities of the patellofemoral joint using high-resolution magnetic resonance imaging (MRI).

PURPOSE

To investigate the presence of structural abnormalities of the patellofemoral joint on high-resolution MRI in patients with PFP compared with healthy control subjects.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Patients with PFP and healthy control subjects between 14 and 40 years of age underwent high-resolution 3-T MRI. All images were scored using the Magnetic Resonance Imaging Osteoarthritis Knee Score with the addition of specific patellofemoral features. Associations between PFP and the presence of structural abnormalities were analyzed using logistic regression analyses adjusted for age, body mass index (BMI), sex, and sports participation.

RESULTS

A total of 64 patients and 70 control subjects were included in the study. Mean ± SD age was 23.2 ± 6.4 years, mean BMI ± SD was 22.9 ± 3.4 kg/m(2), and 56.7% were female. Full-thickness cartilage loss was not present. Minor patellar cartilage defects, patellar bone marrow lesions, and high signal intensity of the Hoffa fat pad were frequently seen in both patients (23%, 53%, and 58%, respectively) and control subjects (21%, 51%, and 51%, respectively). After adjustment for age, BMI, sex, and sports participation, none of the structural abnormalities were statistically significantly associated with PFP.

CONCLUSION

Structural abnormalities of the patellofemoral joint have been hypothesized as a factor in the pathogenesis of PFP, but the study findings suggest that structural abnormalities of the patellofemoral joint on MRI are not associated with PFP.

MRI of the knees in asymptomatic adolescent soccer players: A case-control study

PURPOSE

To determine the range of asymptomatic abnormal findings in adolescent soccer players at 3.0T MRI of the knee.

MATERIALS AND METHODS

In all, 87 knees of asymptomatic 14-17-year-old male adolescents were evaluated at 3T, using a standardized examination protocol comprising four sequences: two fat-suppressed T₂ -weighted fast spin-echo sequences (T₂ FSE), in the sagittal (repetition time / echo time [TR/TE], 5.300/71, echo train length [ETL] 17) and coronal planes (TR/TE, 4234/70, ETL 17), one fat-suppressed proton density (PD) sequence in the axial plane (TR/TE, 2.467/40, ETL 9), and one T₁ -weighted spin-echo (T₁ SE) sequence in the sagittal plane (TR/TE, 684/12.5). Soccer players (46 knees) were paired with controls (41 knees) by age and weight. Bone marrow, articular cartilage, meniscus, tendons, ligaments, fat pad abnormalities, and joint fluid were assessed.

RESULTS

One or more abnormalities were detected in 31 knees (67.4%) in the soccer player group, compared to 20 knees (48.8%) in the control group. The prevalence of bone marrow edema was higher in the soccer group (19 knees, 41.3%) than in the control group (3 knees, 7.3%), P = 0.001. Other abnormalities found in this sample (joint effusion, cartilage lesions, tendinopathy, ganglion cysts, and infrapatellar fat pat edema) were not significantly different between the two study groups.

CONCLUSION

Asymptomatic adolescents had a high prevalence of abnormal findings on knee imaging, especially bone marrow edema. This prevalence was higher among soccer players.

LEVEL OF EVIDENCE

4 J. Magn. Reson. Imaging 2017;45:59-65.

Bone marrow lesions and subchondral bone pathology of the knee

Bone marrow lesions (BMLs) around the knee are a common magnetic resonance imaging (MRI) finding. However, despite the growing interest on BMLs in multiple pathological conditions, they remain controversial not only for the still unknown role in the etiopathological processes, but also in terms of clinical impact and treatment. The differential diagnosis includes a wide range of conditions: traumatic contusion and fractures, cyst formation and erosions, hematopoietic and infiltrated marrow, developmental chondroses, disuse and overuse, transient bone marrow oedema syndrome and, lastly, subchondral insufficiency fractures and true osteonecrosis. Regardless the heterogeneous spectrum of these pathologies, a key factor for patient management is the distinction between reversible and irreversible conditions. To this regard, MRI plays a major role, leading to the correct diagnosis based on recognizable typical patterns that have to be considered together with coexistent abnormalities, age, and clinical history. Several treatment options have been proposed, from conservative to surgical approaches. In this manuscript the main lesion patterns and their management have been analysed to provide the most updated evidence for the differential diagnosis and the most effective treatment.

Impact of lesion location on the progression of osteoarthritis in a rat knee model

To investigate how surgically created acute full-thickness cartilage defects of similar size and location created on the medial versus lateral femoral condyle influence progression of spontaneous cartilage lesions in a rat model. Full-thickness cartilage defects of 1 mm were surgically created on the medial or lateral femoral condyles on the right leg of 20 rats (n = 10/group). Ten rats served as controls. Spontaneous lesion progression on the ipsilateral and contralateral surfaces was examined using a high-resolution digital camera along with H&E and Safranin-O staining. Chondral defects were scored grossly and histologically. Control femur displayed no cartilage disruption. Surgically treated knees exhibited created and spontaneous cartilage defects with no evidence of healing unless subchondral bone was penetrated. Ipsilateral spontaneous lesions on the lateral condyle were significantly more severe on average (p = 0.009) compared to medial lesions on gross examination. Histological examination found contralateral lesions on the lateral surface following surgically created medial lesions to be more severe (p = 0.057) compared to contralateral lesions. A trend toward more susceptible chondral damage to the lateral condyle was observed following acute lesion creation on either medial or lateral condyles. Mechanisms behind this pattern of spontaneous lesion development are unclear, requring further investigation.

Asymptomatic hip/groin pathology identified on magnetic resonance imaging of professional hockey players: outcomes and playing status at 4 years' follow-up

PURPOSE

The purpose of this study was to evaluate the clinical outcomes and playing status of professional hockey players 4 years after they underwent bilateral magnetic resonance imaging (MRI) of asymptomatic hips.

METHODS

Twenty-one professional hockey players with no previous hip/groin pain underwent hip/pelvis MRI. Each MRI study was evaluated by 3 subspecialty-trained musculoskeletal radiologists for alpha-angle measurement and the presence of adductor-abdominal rectus abnormalities, acetabular labral tears, osteochondral lesions of the femoral head or acetabulum, hip effusion, adjacent muscle contusions or strain injury, and stress fractures. The MRI findings of the players were previously published. In the present study, each athlete was followed up by (1) completion of a questionnaire assessing hip/groin dysfunction at 1 and 2 years' follow-up and (2) number of games played over the course of the next 4 years. A significant difference in the number of games played was considered when a player missed more than 5 games compared with the index year.

RESULTS

We enrolled 21 players in the study. Of these players, 4 had no abnormality bilaterally, 10 had muscle strain and/or tendinosis in 1 or both hips, and 15 had labral tears identified in 1 or both hips. Eight players had a combination of labral tears and muscle strain/tendinosis. Of 21 professional hockey players, 16 (76%) and 14 (67%) were available at 1 and 2 years' follow-up, respectively. Nineteen of 21 players (90%) continued to play professional hockey at 4 years' follow-up. The development of any hip and/or pelvis symptoms occurred in only 3 players (14%) within 4 years. Only 1 of the 3 players missed any games because of hip and/or pelvis symptoms. The affected player missed several games because of proximal iliotibial band symptoms that occurred in the third year after MRI.

CONCLUSIONS

Hip/pelvis pathology is commonly uncovered on MRI of asymptomatic hockey players; however, this pathology does not produce symptoms or result in missed games within 4 years in most players.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Correlation between histopathologic, arthroscopic, and magnetic resonance imaging findings in dogs with medial coronoid disease

OBJECTIVE

To describe the magnetic resonance imaging (MRI), arthroscopic, and histopathologic changes in dogs with medial coronoid disease and to identify potential relationships between these findings.

STUDY DESIGN

Retrospective case series.

SAMPLE POPULATION

Twenty-five diseased medial coronoid processes (MCP) were collected from 19 dogs with a confirmed diagnosis of medial coronoid disease that were surgically treated by subtotal coronoid ostectomy. A reference group of normal MCP was collected from 9 dogs euthanatized for reasons unrelated to elbow disease.

METHODS

MCP specimens were evaluated by MRI using a novel grading scheme (all dogs), arthroscopy using a modified Outerbridge scheme (affected dogs only) and histopathology (all dogs).

RESULTS

The common histopathologic findings were subchondral microfractures, subchondral microfractures continuous with cartilaginous fissures, moderate to severe hypercellularity of the marrow space, trabecular bone necrosis, and articular cartilage degeneration. The severity of cartilage disease in the MCP was moderate to severe in most specimens, even in cases with minimal arthroscopic pathology. Three distinct patterns of bone marrow lesion (BML) were identified adjacent to the MCP, but there was no correlation between BML pattern and either histopathologic or arthroscopic findings. There was moderate correlation between modified Outerbridge scores and MRI scores. No correlation was identified between the histopathologic changes and either MRI or arthroscopic scores.

CONCLUSION

There was no significant correlation between the clinical scores and histopathologic changes. Ongoing improvements in the resolution of noninvasive imaging techniques will likely improve description and understanding of the MCP disease in dogs.

Bone marrow edema lesions in the professional runner

BACKGROUND

The clinical significance of an incidental finding of bone marrow edema (BME) on MRI in professional runners is poorly understood.

PURPOSE

To investigate the prevalence and clinical and radiological progression of BME lesions in professional runners who consider themselves to be asymptomatic.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Sixteen athletes (13 men and 3 women; mean age, 22.9 ± 2.7 years) were recruited from the Dutch National Committee middle-distance and long-distance running selection. All athletes had been injury free for the year before the study. Magnetic resonance imaging scans were obtained before the start of the season and at the end of the season. Both pubic bones, hips, knees, and ankles were scanned in a single session. Preseason and postseason Lysholm scores were obtained.

RESULTS

Fourteen of the 16 athletes had BME lesions before the start of the season (45 BME lesions in total). Most BME lesions (69%; 31/45) were located in the ankle joint and foot. More than half of the lesions (58%; 26/45) fluctuated during the season, with new lesions occurring (20%; 9/45) and old lesions disappearing (22%; 10/45). The few clinical complaints that occurred throughout the season were not related to the presence of BME lesions.

CONCLUSION

Almost all asymptomatic athletes showed BME lesions, with more than half of the lesions fluctuating during the season. These data suggest that the incidental finding of a BME lesion on MRI of professional runners should not immediately be related to clinical complaints or lead to an altered training program.

Imaging non-specific wrist pain: interobserver agreement and diagnostic accuracy of SPECT/CT, MRI, CT, bone scan and plain radiographs

Purpose

Chronic hand and wrist pain is a common clinical issue for orthopaedic surgeons and rheumatologists. The purpose of this study was 1. To analyze the interobserver agreement of SPECT/CT, MRI, CT, bone scan and plain radiographs in patients with non-specific pain of the hand and wrist, and 2. to assess the diagnostic accuracy of these imaging methods in this selected patient population.

Materials and Methods

Thirty-two consecutive patients with non-specific pain of the hand or wrist were evaluated retrospectively. All patients had been imaged by plain radiographs, planar early-phase imaging (bone scan), late-phase imaging (SPECT/CT including bone scan and CT), and MRI. Two experienced and two inexperienced readers analyzed the images with a standardized read-out protocol. Reading criteria were lesion detection and localisation, type and etiology of the underlying pathology. Diagnostic accuracy and interobserver agreement were determined for all readers and imaging modalities.

Results

The most accurate modality for experienced readers was SPECT/CT (accuracy 77%), followed by MRI (56%). The best performing, though little accurate modality for inexperienced readers was also SPECT/CT (44%), followed by MRI and bone scan (38% each). The interobserver agreement of experienced readers was generally high in SPECT/CT concerning lesion detection (kappa 0.93, MRI 0.72), localisation (kappa 0.91, MRI 0.75) and etiology (kappa 0.85, MRI 0.74), while MRI yielded better results on typification of lesions (kappa 0.75, SPECT/CT 0.69). There was poor agreement between experienced and inexperienced readers in SPECT/CT and MRI.

Conclusions

SPECT/CT proved to be the most helpful imaging modality in patients with non-specific wrist pain. The method was found reliable, providing high interobserver agreement, being outperformed by MRI only concerning the typification of lesions. We believe it is beneficial to integrate SPECT/CT into the diagnostic imaging algorithm of chronic wrist pain.