Association between scapula bony morphology and snapping scapula syndrome

HYPOTHESIS AND BACKGROUND

Scapular incongruity has been described as a contributing factor to the development of snapping scapula syndrome (SSS). The purpose of this retrospective case-control study was to determine the association between scapula bony morphology on magnetic resonance imaging (MRI) and the diagnosis of SSS.

METHODS

Bony morphologies of the scapula were evaluated on MRI scans of 26 patients with SSS and 19 patients with non-SSS pathologies. The medial scapula corpus angle (MSCA) was measured on axial MRI sequences. Scapulae were categorized as straight, S shaped, or concave. Two independent observers performed the measurements. Interobserver and intraobserver agreements of MSCA measurements were determined with intraclass correlation coefficients.

RESULTS

Axial scapula bony morphology identified 28 scapulae of the straight type, 14 S-shaped scapulae, and 5 concave scapulae. All 5 concave scapulae had confirmed SSS. Measurement of the MSCA showed excellent interobserver agreement of 0.80 (95% confidence interval [CI], 0.67 to 0.89) and intraobserver agreement of 0.70 (95% CI, 0.52 to 0.82). There were significant differences in the mean MSCAs between shoulders with SSS (14.4° ± 19.3°) and non-SSS shoulders (-3.3° ± 15.3°, P = .001). The odds ratio was 8.4 (95% CI, 2.2 to 31.8) for positive MSCA and SSS. The scapulothoracic distance was significantly decreased in the SSS group (14.9 ± 5.8 mm) compared with the non-SSS patients (24.0 ± 6.7 mm, P < .001).

DISCUSSION AND CONCLUSION

Anterior angulation of the medial scapula in the axial plane was associated with SSS. Patients with a concave-shaped scapula and a positive MSCA have a 12-fold increased risk of SSS. The MSCA may prove helpful in determining the location and amount of scapular resection needed for patients with SSS.

Comparison of T2 Values in the Lateral and Medial Portions of the Weight-Bearing Cartilage of the Hip for Patients With Symptomatic Femoroacetabular Impingement and Asymptomatic Volunteers

PURPOSE

To develop a simplified method to define a clinically relevant subregion in the course of arthroscopic treatment of femoroacetabular impingement (FAI) using T2 mapping in patients and asymptomatic volunteers. Additionally, we sought to compare the lateral and medial subregion values in asymptomatic volunteers and in patients presenting with FAI. Finally, we wanted to investigate possible associations between patients' T2 mapping values and demographic variables-i.e., alpha angle, age, sex, and body mass index (BMI).

METHODS

Twenty-five asymptomatic volunteers and 23 consecutive symptomatic patients with FAI (cam or mixed type) were prospectively enrolled and evaluated with a sagittal T2 mapping sequence. The weight-bearing region of the acetabular and femoral cartilage was manually segmented and divided into medial and lateral subregions. Median T2 values were determined, and patient characteristics were assessed as potential predictors of T2 values.

RESULTS

T2 values in the lateral portion of the acetabulum were lower than in the medial portion for both asymptomatic volunteers (43 v 53 ms; P < .001) and patients with FAI (42 v 49 ms; P = .016). The medial acetabulum (MA) of asymptomatic volunteers had higher T2 values than those of the FAI group (53 v 49 ms; P = .040). The lateral-minus-medial difference was significantly larger among asymptomatic volunteers than in patients with FAI (P = .047). Patients with FAI had higher alpha angles than those of the asymptomatic volunteers, but no other associations with patient characteristics were observed.

CONCLUSIONS

This study's findings suggest that there are differences in cartilage T2 mapping values between medial and lateral weight-bearing aspects of the hip and may expand the application and usefulness of biochemical magnetic resonance imaging (MRI) techniques, specifically T2 mapping, in the diagnosis of hip cartilage damage with the evaluation of clinically relevant subregions. When comparing asymptomatic volunteers and patients with FAI presenting with cam or mixed type deformity, we observed a significant contrast between the T2 mapping values of the lateral and medial portions of the weight-bearing zone of the acetabular cartilage, whereas such contrast was not observed when zone 3 was analyzed as a whole.

LEVEL OF EVIDENCE

Level III, development of diagnostic criteria on the basis of consecutive patients with a universally applied reference gold standard.

Diagnostic accuracy of 3.0 Tesla magnetic resonance imaging for the detection of articular cartilage lesions of the talus

BACKGROUND

Talar chondral defects can be a source of persistent ankle pain and disability. If untreated, there is an increased risk of osteoarthritis. The purpose of our study was to determine diagnostic accuracy of 3T MRI in detecting Outerbridge grades 3 and 4 articular cartilage lesions of the talus in a clinical setting, utilizing a standardized clinical MRI protocol.

METHODS

Patients who had a 3T ankle MRI and subsequent ankle surgery, by a single surgeon, were included in this study. MRI exams were performed 180 days or less before surgery. Seventy-nine ankles in 78 patients (mean age of 42.3 years) were included in this study. Mean body mass index was 26.3. A standard clinical MRI exam was performed on a 3T MRI scanner. Mean days from MRI to surgery was 39 days. All MRI exams were read and findings recorded by a musculoskeletal radiologist. Arthroscopic examination was performed by a single orthopaedic surgeon. Detailed arthroscopic findings and demographic data were collected prospectively and stored in a data registry. Of the 78 patients, 31 (39.2%) reported previous ankle surgery. Pain was the primary reason for seeking medical attention as reported by 95% of patients, followed by instability in 44% and loss of function with 42%.

RESULTS

Prevalence of Outerbridge grade 3 and 4 talar articular cartilage defects identified at arthroscopy was 17.7%. The 3T MRI demonstrated a sensitivity of 0.714, specificity of 0.738, positive predictive value of 0.370, and negative predictive value of 0.923.

CONCLUSION

Sensitivity and specificity levels were acceptable for detection of grades 3 and 4 articular cartilage defects of the talar dome using 3T MRI. The high negative predictive value may be beneficial in preoperative planning. While these values are acceptable, a high index of suspicion should be maintained in the appropriate clinical setting.

Patient-centered outcomes after hip arthroscopy for femoroacetabular impingement and labral tears are not different in patients with normal, high, or low femoral version

PURPOSE

The purpose of this study was to determine whether outcomes after hip arthroscopy were different based on femoral version.

METHODS

The inclusion criteria were diagnosis of femoroacetabular impingement (FAI) based on clinical examination and/or imaging findings and preoperative measurement of femoral version by magnetic resonance imaging. For this study, the definition of FAI was a positive impingement sign, a positive flexion-abduction-external rotation examination finding, or radiographic signs of impingement. A query of a prospective data registry identified 180 patients who matched the inclusion and exclusion criteria. Group 1 had version of less than 5° (n = 48), group 2 had version of 5° to 15° (n = 84), and group 3 had version greater than 15° (n = 48). The mean age of the patients was 35 years (range, 18 to 61 years).

RESULTS

On radiographic examination, the mean alpha angle for all patients' injured hips was 63° (range, 42° to 88°). The mean center-edge angle was 30° (range, 20° to 43°), and mean femoral version was 9.9° (range, -16° to 29°). There was no significant difference in age, alpha angle, or center-edge angle among the 3 version groups. A significant difference in psoas release procedures (psoas impingement) was seen with increasing femoral version. The mean follow-up period was 30 months (range, 18 to 47 months). Patient-reported functional outcomes were not statistically different among the groups.

CONCLUSIONS

Patient-reported functional outcomes after hip arthroscopy for labral tears and FAI were not different based on femoral version in this population. Although some differences were observed regarding intraoperative findings, these also did not result in differences in patient outcomes reported at a mean follow-up of 2 years.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Systematic technique-dependent differences in CT versus MRI measurement of the tibial tubercle-trochlear groove distance

BACKGROUND

The tibial tubercle-trochlear groove (TTTG) distance is used to quantify the degree of lateralization of the patellar tendon insertion on the tibial tubercle relative to the deepest part of the trochlear groove. Disagreement exists as to whether the TTTG distance measured on computed tomography (CT) and magnetic resonance imaging (MRI) can be considered equivalent.

PURPOSE

To compare TTTG distance as measured on axial CT and MRI and to investigate the potential effect of patient positioning between modalities.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

Patients who received both CT and MRI of the same knee for any indication from August 2010 to April 2014 were included in this study. The TTTG distances were measured twice by 2 raters in a randomized order, with at least 30 days between ratings to minimize recall bias. Inter- and intrarater reliability of CT and MRI measurements and intermethod reliability were assessed with intraclass correlation coefficients (ICCs). Bland-Altman plots were also created to assess agreement. Differences in patient positioning were investigated to determine its effect on the TTTG distance.

RESULTS

Fifty-nine patients (age, 32.8 ± 12.9 years) were included. Interrater ICCs were excellent for both CT and MRI measurements. Intrarater ICCs were excellent for both raters. Absolute agreement ICCs for intermethod reliability were fair to good, but consistency type agreement was excellent. A systematic bias of lower MRI distances (bias = -2.8 mm) compared with CT was observed. The investigation of CT versus MRI imaging techniques demonstrated that the standard MRI examination places the knee in approximately 4.6° of relative varus alignment compared with CT.

CONCLUSION

A systematic bias toward lower TTTG distances on MRI compared with CT was found. This finding is likely dependent on imaging technique, including patient positioning. Patient knees were positioned in varus on the MRI compared with the CT examination, with resulting lower TTTG distances on MRI compared with CT. The TTTG distances on CT and MRI vary with imaging technique, which may be attributable to patient positioning and result in differences among imaging centers.

Diagnostic accuracy of 3.0 T magnetic resonance imaging for the detection of meniscus posterior root pathology

PURPOSE

The purpose of this study was to determine the diagnostic accuracy of 3 T MRI, including sensitivity, specificity, negative and positive predictive values, for detection of posterior medial and lateral meniscus root tears and avulsions.

METHODS

All patients who had a 3 T MRI of the knee, followed by arthroscopic surgery, were included in this study. Arthroscopy was considered the gold standard. Meniscus root tears diagnosed at arthroscopy and on MRI were defined as a complete meniscus root detachment within 9 mm of the root. All surgical data were collected prospectively and stored in a data registry. MRI exams were reported prospectively by a musculoskeletal radiologist and reviewed retrospectively.

RESULTS

There were 287 consecutive patients (156 males, 131 females; mean age 41.7 years) in this study. Prevalence of meniscus posterior root tears identified at arthroscopy was 9.1, 5.9% for medial and 3.5% for lateral root tears (one patient had both). Sensitivity was 0.770 (95% CI 0.570, 0.901), specificity was 0.729 (95% CI 0.708, 0.741), positive predictive value was 0.220 (95% CI 0.163, 0.257) and negative predictive value was 0.970 (95% CI 0.943, 0.987). For medial root tears, sensitivity was 0.824 (95% CI 0.569, 0.953), specificity was 0.800 (95% CI 0.784, 0.808), positive predictive value was 0.206 (95% CI 0.142, 0.238) and negative predictive value was 0.986 (95% CI 0.967, 0.996). For lateral meniscus posterior root tears, sensitivity was 0.600 (95% CI 0.281, 0.860), specificity was 0.903 (95% CI 0.891, 0.912), positive predictive value was 0.181 (95% CI 0.085, 0.261) and negative predictive value was 0.984 (95% CI 0.972, 0.994).

CONCLUSIONS

This study demonstrated moderate sensitivity and specificity of 3 T MRI to detect posterior meniscus root tears. The negative predictive value of 3 T MRI to detect posterior meniscus root tears was high; however, the positive predictive value was low. Sensitivity was higher for medial root tears, indicating a higher risk of missing lateral root tears on MRI. Imaging has an important role in identifying meniscus posterior horn root tears; however, some root tears may not be identified until arthroscopy.

LEVEL OF EVIDENCE

Prognostic study (diagnostic), Level II.

Subregional Anatomical Distribution of T2 Values of Articular Cartilage in Asymptomatic Hips

OBJECTIVE

A standardized definition of normative T2 values across the articular surface of the hip must be defined in order to fully understand T2 values for detecting early degeneration. Therefore, in this article, we seek to lay foundational methodology for reproducible quantitative evaluation of hip cartilage damage using T2 mapping to determine the normative T2 values in asymptomatic individuals.

DESIGN

Nineteen prospectively enrolled asymptomatic volunteers (age 18-35 years, males 10, females 9, alpha angle 49.3º ± 7.2º) were evaluated with a sagittal T2 mapping sequence at 3.0 T magnetic resonance imaging. Acetabular and femoral cartilage was manually segmented directly on the second echo of the T2 mapping sequence by 3 raters, twice. Segmentations were divided into 12 subregions modified from the geographic zone method. Median T2 values within each subregion were compiled for further analysis and interrater and intrarater reliability was assessed.

RESULTS

In the femur, the posterior-superior subregion was significantly higher (P ≤ 0.05) than those in the posterior-inferior and anterior-inferior subregions. In the acetabulum, the anterior-inferior subregion was significantly higher (P ≤ 0.001) than in the anterior-superior, middle, and posterior-inferior subregions. T2 values of the posterior-superior subregion were significantly higher (P ≤ 0.05) than the anterior-superior, middle, and posterior-inferior subregions. Interrater agreement was generally fair to good.

Quantitative MRI in the evaluation of articular cartilage health: reproducibility and variability with a focus on T2 mapping

PURPOSE

Early diagnosis of cartilage degeneration and longitudinal tracking of cartilage health including repair following surgical intervention would benefit from the ability to detect and monitor changes of the articular cartilage non-invasively and before gross morphological alterations appear.

METHODS

Quantitative MR imaging has shown promising results with various imaging biomarkers such as T2 mapping, T1 rho and dGEMRIC demonstrating sensitivity in the detection of biochemical alterations within tissues of interest. However, acquiring accurate and clinically valuable quantitative data has proven challenging, and the reproducibility of the quantitative mapping technique and its values are essential. Although T2 mapping has been the focus in this discussion, all quantitative mapping techniques are subject to the same issues including variability in the imaging protocol, unloading and exercise, analysis, scanner and coil, calculation methods, and segmentation and registration concerns.

RESULTS

The causes for variability between time points longitudinally in a patient, among patients, and among centres need to be understood further and the issues addressed.

CONCLUSIONS

The potential clinical applications of quantitative mapping are vast, but, before the clinical community can take full advantage of this tool, it must be automated, standardized, validated, and have proven reproducibility prior to its implementation into the standard clinical care routine.

Preoperative diagnosis of pathologic conditions of the ligamentum teres: is MRI a valuable imaging modality?

PURPOSE

The purpose of this study was to determine the accuracy of 3-Tesla magnetic resonance imaging (MRI) in detecting ligamentum teres (LT) lesions in patients before they undergo hip arthroscopy for the treatment of femoroacetabular impingement.

METHODS

From 2010 to 2011, data were prospectively collected on all patients presenting for treatment of hip pain. All patients underwent MRI followed by arthroscopic surgery. A radiologist prospectively documented MRI findings, and the surgeon recorded the findings at arthroscopy. Radiologic and surgical data included classification of the LT as not torn, hypertrophic, partially torn, or completely torn. All MR images were read by a single radiologist, and all surgery was performed by a single surgeon. Arthroscopy was considered the diagnostic gold standard.

RESULTS

One hundred forty-two patients with a mean patient age of 35 years (range, 19 to 73 years) met the inclusion criteria. Only one complete LT tear was found in the study. The accuracy of MRI for the diagnosis of LT partial tears was 64%. The sensitivity and specificity of MRI for diagnosing partial tears of the LT were 9% and 91%, [corrected] respectively. The positive predictive value and negative predictive value were 31% and 67%, [corrected] respectively. The sensitivity and specificity of MRI for diagnosing hypertrophic LT were 32% and 78%, respectively.

CONCLUSIONS

In this patient population, MRI demonstrated sensitivity and specificity of 34% and 50%, [corrected] respectively, in identifying any pathologic process of the LT. MRI is capable of ruling out [corrected] partial tears of the LT with high sensitivity (91%) and negative [corrected] predictive value (67%).

LEVEL OF EVIDENCE

Level II, development of diagnostic criteria on basis of consecutive patients with universally applied gold standard.

Automatic model-based semantic registration of multimodal MRI knee data

PURPOSE

To propose a robust and automated model-based semantic registration for the multimodal alignment of the knee bone and cartilage from three-dimensional (3D) MR image data.

MATERIALS AND METHODS

The movement of the knee joint can be semantically interpreted as a combination of movements of each bone. A semantic registration of the knee joint was implemented by separately reconstructing the rigid movements of the three bones. The proposed method was validated by registering 3D morphological MR datasets of 25 subjects into the corresponding T2 map datasets, and was compared with rigid and elastic methods using two criteria: the spatial overlap of the manually segmented cartilage and the distance between the same landmarks in the reference and target datasets.

RESULTS

The mean Dice Similarity Coefficient (DSC) of the overlapped cartilage segmentation was increased to 0.68 ± 0.1 (mean ± SD) and the landmark distance was reduced to 1.3 ± 0.3 mm after the proposed registration method. Both metrics were statistically superior to using rigid (DSC: 0.59 ± 0.12; landmark distance: 2.1 ± 0.4 mm) and elastic (DSC: 0.64 ± 0.11; landmark distance: 1.5 ± 0.5 mm) registrations.

CONCLUSION

The proposed method is an efficient and robust approach for the automated registration between morphological knee datasets and T2 MRI relaxation maps.

MRI T2 mapping of the asymptomatic supraspinatus tendon by age and imaging plane using clinically relevant subregions

PURPOSE

Diagnosis of partial rotator cuff tears and tendonopathy using conventional MRI has proven variable. Quantitative T2 mapping may have application for assessing rotator cuff health. In order to evaluate the usefulness of T2 mapping for the rotator cuff, methods must be refined for mapping the supraspinatus tendon, and normative T2 values must first be acquired.

MATERIALS AND METHODS

This study was IRB approved. Thirty asymptomatic volunteers (age: 18-62) were evaluated with sagittal and coronal T2 mapping sequences. Manual segmentation of tendon and muscle as a unit and tendon alone was performed twice by two independent raters. Segmentations were divided into medial, middle and lateral subregions and mean T2 values calculated.

RESULTS

Anatomic comparison of mean T2 values illustrated highest values in the medial region, lowest values in the lateral region, and intermediate values for the middle region upon coronal segmentation (p<0.001). In sagittal segmentations, there were higher values in the medial region and no significant differences between the lateral and middle subregions. No significant differences were found with comparison across age groups. Inter and intra-rater segmentation repeatability was excellent, with coefficients ranging from 0.85 to 0.99.

CONCLUSION

T2 mapping illustrated anatomic variation along the supraspinatus muscle-tendon unit with low standard deviations and excellent repeatability, suggesting that changes in structure due to degeneration or changes associated with healing after repair may be detectable.

Magnetic resonance imaging findings of snowboarding osteochondral injuries to the middle talocalcaneal articulation

This report presents 2 cases of subtle injuries to the subtalar joint, specifically, osteochondral defects of the middle facet of the talus and concomitant involvement of the middle talocalcaneal articulation sustained while snowboarding. The 3T magnetic resonance image revealed fracture of the lateral talar process with osteochondral lesions of the middle talocalcaneal articulation. This injury can lead to severe and chronic disability if undetected and could ultimately end athletic participation prematurely.

Clinically Relevant Subregions of Articular Cartilage of the Hip for Analysis and Reporting Quantitative Magnetic Resonance Imaging: A Technical Note

OBJECTIVE

Before quantitative imaging techniques can become clinically valuable, the method, and more specifically, the regions of locating and reporting these values should be standardized toward reproducibility comparisons across centers and longitudinal follow-up of individual patients. The purpose of this technical note is to describe a rigorous and reproducible method of locating, analyzing, and reporting quantitative MRI values in hip articular cartilage with an approach that is consistent with current orthopedic literature.

DESIGN

To demonstrate this localization and documentation, 3 patients (age, 23 ± 5.1 years; 2 males, 1 female) who presented with symptomatic mixed-type femoroacetabular impingement (α angle, 63.3° ± 2.1°; center edge angle, 39° ± 4.2°) were evaluated with T2-mapping at 3 T MRI prior to hip arthroscopy. Manual segmentation was performed and cartilage of the acetabulum and femur was divided into 12 subregions adapted from the geographic zone method. Bone landmarks in the acetabulum and femur, identifiable both in arthroscopy and MR images, were manually selected and the coordinates exported for division of cartilage.

RESULTS

Mean T2 values in each zone are presented.

CONCLUSIONS

The current work outlines a standardized system to locate and describe quantitative mapping values that could aid in surgical decision making, planning, and the noninvasive longitudinal follow-up of implemented cartilage preservation and restoration techniques.

Prevalence of increased alpha angles as a measure of cam-type femoroacetabular impingement in youth ice hockey players

BACKGROUND

It has been reported that relative to other sports participants, ice hockey players suffer from cam-type femoroacetabular impingement (FAI) in higher numbers. α angles have been reported to increase with the likelihood of symptomatic FAI. It is unclear how prevalent increased α angles, commonly associated with cam FAI, are in asymptomatic young ice hockey players.

HYPOTHESIS

There would be a higher prevalence of α angles associated with cam FAI in youth ice hockey players than in a non-hockey-playing (skier) youth control group.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 61 asymptomatic youth ice hockey players (aged 10-18 years) and 27 youth skiers (controls) (aged 10-18 years) underwent a clinical hip examination consisting of the flexion/abduction/external rotation (FABER) distance test, impingement testing, and measurement of hip internal rotation. The hip α angle was measured by magnetic resonance imaging, and labral tears and articular cartilage lesions were documented. Hockey players were grouped according to their USA Hockey classification as peewees (ages 10-12 years), bantams (ages 13-15 years), and midgets (ages 16-19 years).

RESULTS

Overall, ice hockey players had significantly higher α angles than did the control group, and hockey players had a significant correlation between increased age and increased α angles, while the control group did not. In the ice hockey group, 75% had an α angle of ≥55°, while in the skier group, 42% had an α angle of ≥55° (P < .006). Hockey players were 4.5 times more likely to have an α angle commonly associated with cam impingement than skiers. Midget players had the highest risk of increased α angles.

CONCLUSION

Even at young ages, ice hockey players have a greater prevalence of α angles associated with cam FAI than do skier-matched controls. Properties inherent to ice hockey likely enhance the development of a bony overgrowth on the femoral neck, leading to cam FAI.

Relationship between femoral anteversion and findings in hips with femoroacetabular impingement

The purpose of this study was to investigate the relationship between femoral neck version and pre- and intraoperative findings in hips with femoroacetabular impingement (FAI). The authors retrospectively reviewed prospectively collected data on 188 patients (204 hips) who underwent hip arthroscopy for FAI and labral pathology. Femoral version was measured on magnetic resonance imaging by a fellowship-trained musculoskeletal radiologist. The study group comprised 100 men and 88 women with a mean age of 35 years (range, 18 to 62 years). Mean femoral version was 9° (range, -10° to 27°). No relationship was found between femoral version and patient demographics (ie, age, sex, weight, height, and body mass index). A significant correlation was found between version and degrees of external rotation (r=-0.208; P=.027) and internal rotation (r=0.231; P=.002) on physical examination. Patients with femoral version less than 5° had significantly increased external rotation (P=.027). Intraoperative findings demonstrated that femoral version greater than 15° was related to larger labral tears that averaged approximately 38 mm in size, whereas patients with anteversion less than 5° had tear sizes measuring 30 mm and patients with angles between 5° and 15° had tear sizes averaging 34 mm (P=.008). Hips with femoral version greater than 15° were 2.2 times more likely (95% confidence interval, 1.2 to 4.1) to have labral tears that extended beyond the 3 o'clock position, denoting more anterior tears. Hips in which a psoas release was performed had higher version angles (8° vs 11°; P=.023).

Prevalence of abnormal hip findings in asymptomatic participants: a prospective, blinded study

BACKGROUND

The prevalence of abnormal magnetic resonance imaging (MRI) findings in an asymptomatic population has yet to be determined.

PURPOSE

The purpose of this study was to assess a cohort of asymptomatic people to determine the prevalence of hip lesions.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Forty-five volunteers with no history of hip pain, symptoms, injury, or surgery were recruited for enrollment in this institutional review board-approved study. The subjects underwent a unilateral MRI scan with a Siemens 3.0-tesla scanner. The extremity side evaluated by MRI was alternated. All MRI scans were reviewed by 3 fellowship-trained musculoskeletal radiologists. The scans were mixed randomly with 19 scans from symptomatic patients to blind the radiologists to the possibility of patient symptoms. An abnormal finding was considered positive when 2 of 3 radiologists agreed on its presence.

RESULTS

The average age of volunteers was 37.8 years (range, 15-66 y); 60% were men. Labral tears were identified in 69% of hips, chondral defects in 24%, ligamentum teres tears in 2.2%, labral/paralabral cysts in 13%, acetabular bone edema in 11%, fibrocystic changes of the head/neck junction in 22%, rim fractures in 11%, subchondral cysts in 16%, and osseous bumps in 20%. Participants older than 35 years were 13.7 times (95% CI, 2.4-80 times) more likely to have a chondral defect and 16.7 times (95% CI, 1.8-158 times) more likely to have a subchondral cyst compared with participants 35 or younger. No other joint lesions were associated with age. Male subjects were 8.5 times (95% CI, 1.2-56 times) more likely to have an osseous bump than female subjects. No other joint lesions were associated with sex.

CONCLUSION

Magnetic resonance images of asymptomatic participants revealed abnormalities in 73% of hips, with labral tears being identified in 69% of the joints. A strong correlation was seen between participant age and early markers of cartilage degeneration such as cartilage defects and subchondral cysts.

The effect of sequence selection and field strength on detection of osteochondral defects in the metacarpophalangeal joint

Six cadaver forelimbs were imaged in two high-field magnetic resonance (MR) systems and one low-field MR system following the creation of osteochondral defects on the palmar distal aspect of the third metacarpal bone. The following sequences were performed using all three systems: proton density (PD) turbo spin echo, T2* gradient echo (GRE), T2-weighted fast spin echo, and short tau inversion recovery. In addition, 3D T1 GRE sagittal standard and motion insensitive sequences were obtained using the low-field system. PD fat saturated and 3D T1-weighted spoiled GRE images with and without fat suppression were acquired with the high-field systems. Lesions were measured and assigned a confidence score. The images obtained using high-field systems (1.0 and 1.5 T) more accurately represented the osteochondral defects when compared with low-field system (0.27 T) images. The largest difference was observed when evaluating articular cartilage defects, which were not identified on the low-field images. Sequence selection affected the appearance of the lesions. On all systems the turbo and fast spin echo sequences more accurately represented the lesion size and shape when compared with the GRE sequences. The T1 GRE sequence is the only sequence that appears to allow visualization of the articular cartilage on the low-field images, but is limited in providing adequate cartilage visualization. Confidence scores were greater on the high-field systems when compared with the low-field system.

Elucidating the process of co-composting of biosolids and spent activated clay

This study elucidates the co-composting of biosolids and spent activated clay (SAC) using physio-chemical, bioassay, and spectroscopic methods. A pilot-scale pile of blended limed biosolids, SAC, and rice husk was composted for 15weeks. The changes in temperature, pH, Fourier-transform infrared (FT-IR) spectra, C/N, and germination index (GI) of Chinese cabbage (Brassica chinensis) seeds with time support the goal of producing a mature compost with a decline in the SAC acidity of associated with biosolids. Cadmium, Cr, Cu, Ni, and Pb in the initial biosolids were converted from labile fractions into relatively immobile phases upon maturation. Temperature, moisture, pH, C/N, and GI were used to separate the composting process into three phases - initial, thermophilic, and cooling, based on a score plot of principal component analysis (PCA). The values of the parameters of interest reveal that the compost fulfills the requirements of compost maturity in the literature.

Magnetic resonance imaging findings in horses with recent onset navicular syndrome but without radiographic abnormalities

Seventy-two horses with recent onset of navicular syndrome and normal radiographs were assessed. Horses underwent magnetic resonance (MR) imaging of both front feet. All abnormalities were characterized and the most severe abnormality identified, if possible. Abnormal signal intensity in the navicular bone was the most severe abnormality in 24 (33%) horses. Pathologic change in the deep digital flexor tendon was the most severe abnormality in 13 (18%) horses. Pathologic change in the collateral sesamoidean ligament was the most severe abnormality in 11 (15%) horses. Pathologic change in the distal sesamoidean impar ligament was the most severe abnormality in seven (10%) horses. Multiple abnormalities were observed in 13 (18%) horses in which an abnormality that was more severe than the others could not be determined. Abnormalities were not observed in the navicular bone or its supporting soft tissues in four (5%) horses. Fifty-six horses had abnormalities that were most severe in one limb; in 52 (93%) horses, the most severe abnormalities were in the foot of the most lame limb. In 7% (4/56) of horses, the most severe findings were in the opposite limb, and in 16 horses, the findings on both limbs were similar. MR imaging is a useful technique for evaluating horses with navicular syndrome and can differentiate between multiple abnormalities. This provides a more specific diagnosis which affects further treatment of the horse. Pathologic changes in different locations in the foot can cause similar clinical signs that, before MR imaging, were categorized as one syndrome.