Presurgical Perspective and Postsurgical Evaluation of Morton's Neuroma and Other Nerve Lesions.

Magnetic resonance imaging (MRI) is a robust method used for both preoperative and postoperative evaluation of Morton's neuroma and other neural lesions. MRI is used to confirm the diagnosis and for precise localization, estimation of outcome, and differential diagnoses. The differential diagnoses include mechanically induced plantar plate ruptures with associated Morton's neuroma-like tumors in the intermetatarsal/interdigital spaces; mechanical fibrosis cushion formations and pseudo bursae in the plantar foot adipose tissue; rheumatologic affections, such as rheumatoid nodules, gouty nodules, and intermetatarsal bursitis; and lastly the tenosynovial giant cell tumor (formerly called pigmented villonodular synovitis). In the postoperative evaluation after resection of Morton's neuroma, the same differential diagnoses must be considered as in the preoperative evaluation. Similarly, a high prevalence (up to 25%) of asymptomatic Morton's neuroma-like findings in the intermetatarsal and interdigital spaces should be kept in mind when interpreting postoperative recurrent forefoot pain after Morton's neuroma resection.

Assessment of hindfoot alignment using MRI and standing hindfoot alignment radiographs (Saltzman view).

OBJECTIVE: To compare the hindfoot alignment measured on standing HAV radiographs (Saltzman view) and on non-weight-bearing coronal MR images. MATERIALS AND METHODS: The apparent moment arm was measured on weight-bearing conventional radiographs (Saltzman views) and on MRIs of the ankle in 50 consecutive patients (mean age, 54 years; age range, 18-77 years). The evaluation was performed independently by three readers using analogous reference points for both methods. Positive values were assigned when the deepest point of the calcaneus was lateral to the tibial axis as valgus, negative values as varus. The intertechnique agreement and correlation for the measurements performed with HAV radiographs and MRI were assessed for each reader using the Bland-Altman method and the Pearson correlation coefficient, respectively. The interobserver agreement was assessed using the intraclass correlation coefficient. RESULTS: The means of apparent moment arms, with the standard deviation (SD) in parentheses, of three readers were +2.0 (±8.4) mm, +1.5 (±6.6) mm and -1.4 (±8.2) mm on HAV radiographs and +4.6 (±7.4) mm, +6.3 (±5.3) mm and +5.4 (±6.4) mm on MRI. The Bland-Altman analysis found a systematic bias for all three readers, corresponding to an overestimation of measurements with MRI (systematic bias ranging from 2.6 to 4.8 mm). The intertechnique correlation was found moderate to high. The Pearson coefficients for the three readers were 0.75, 0.64 and 0.65. The interobserver agreement among the three readers was 0.72, 0.77 and 0.68 for HAV, MRI and both modalities together, respectively. CONCLUSION: Hindfoot alignment can be estimated on MRI but the correlation between the values on HAV radiographs and MR images is only moderate with a tendency to increased positive values (valgization) on MR images.

The tactics and technique of musculoskeletal biopsy.

The treatment of musculoskeletal neoplasms and infection is usually based on an initial diagnostic biopsy.Prior to biopsy, a hypothesis should be formed about the most likely diagnosis and a differential diagnosis. These deliberations should consider whether the lesion is a primary benign or malignant tumour, a metastasis, a haematological problem or an infection.A tactical plan should be developed which evaluates the necessity, the risk, the approach and finally defines the technique of biopsy most likely to achieve a representative result in the clinical case.In developing this technical approach, the pitfalls should be anticipated, i.e. inadequate sampling, difficulty of pathological interpretation and contamination.The tactical approach should be developed in conjunction with a multi-disciplinary team together with appropriate pre-biopsy imaging. Cite this article: EFORT Open Rev 2017;2:51-57. DOI: 10.1302/2058-5241.2.160065.

Is there an Added Value of T1-Weighted Contrast-Enhanced Fat-suppressed Spin-Echo MR Sequences Compared to STIR Sequences in MRI of the Foot and Ankle?

OBJECTIVES: To prospectively compare T1-weighted fat-suppressed spin-echo magnetic resonance (MR) sequences after gadolinium application (T1wGdFS) to STIR sequences in patients with acute and chronic foot pain. METHODS: In 51 patients referred for MRI of the foot and ankle, additional transverse and sagittal T1wGdFS sequences were obtained. Two sets of MR images (standard protocol with STIR or T1wGdFS) were analysed. Diagnosis, diagnostic confidence, and localization of the abnormality were noted. Standard of reference was established by an expert panel of two experienced MSK radiologists and one experienced foot surgeon based on MR images, clinical charts and surgical reports. Patients reported prospectively localization of pain. Descriptive statistics, McNemar test and Kappa test were used. RESULTS: Diagnostic accuracy with STIR protocol was 80% for reader 1, 67% for reader 2, with contrast-protocol 84%, both readers. Significance was found for reader 2. Diagnostic confidence for reader 1 was 1.7 with STIR, 1.3 with contrast-protocol; reader 2: 2.1/1.7. Significance was found for reader 1. Pain location correlated with STIR sequences in 64% and 52%, with gadolinium sequences in 70% and 71%. CONCLUSIONS: T1-weighted contrast material-enhanced fat-suppressed spin-echo magnetic resonance sequences improve diagnostic accuracy, diagnostic confidence and correlation of MR abnormalities with pain location in MRI of the foot and ankle. However, the additional value is small. KEY POINTS: • Additional value of contrast-enhanced MR over standard MR with STIR sequences exists. • There is slightly more added value for soft tissue than for bony lesions. • This added value is limited. • Therefore, application of contrast material cannot be generally recommended.

MR imaging of healthy knees in varying degrees of flexion using a stretchable coil array provides comparable image quality compared to a standard knee coil array.

OBJECTIVE: Stretchable coils allow knee imaging at varying degrees of flexion. Purpose was to compare a new-developed stretchable 8-channel to a standard 8-channel knee coil array by means of quantitative and qualitative image analysis. MATERIAL AND METHODS: IRB approved prospective study. Knee MR imaging in 10 healthy volunteers was performed at 3T using a standard 8-channel and a new-developed stretchable 8-channel coil array at 0°, 45°, and 60° of flexion and at 0° (standard coil). Image parameters were identical. Signal-to-noise ratio (SNR) was determined by combining the images with separately acquired noise data on a pixel-by-pixel basis using MATLAB routines (Natick, MA, USA). Images were qualitatively analysed by two independent radiologists who graded the visibility of several anatomic structures from 1=not visible to 5=excellent. ANOVA, Wilcoxon and kappa statistics were used. RESULTS: Mean SNR±standarddeviation of bone was 54.7±10.4 and of muscle 28.0± 4.4 using the stretchable coil array and 54.6±8.2 and 33.4±4.5, respectively, using the standard knee coil array. No statistically significant SNR differences were found between both arrays (bone, p=0.960; muscle, p=0.132). SNR was not degraded at higher degrees of flexion. The qualitative image analysis did not reveal statistically significant differences between the stretchable and standard coil array with regard to the visibility of anatomic structures (p=0.026-1.000). Overall kappa was 0.714. CONCLUSION: Stretchable 8-channel coil arrays provide similar SNR and visibility of anatomic structures compared to standard 8-channel knee coil arrays. MR imaging with high SNR will now be possible in flexed knees.

Good correlation of goutallier rating of supraspinatus fatty changes on axial and reformatted parasagittal computed tomographic images.

UNLABELLED: Traumatic tendon tear of the rotator cuff occurs frequently and leads to fatty muscle infiltration. With regard to the outcome, fatty infiltration of the rotator cuff muscles constitutes a major negative predictive factor after rotator cuff surgery. In 1989, Goutallier et al established his classification system for assessment of fatty infiltration of the rotator cuff muscles. He used computed tomographic (CT) images in the axial plane. Today, the assessment of rotator cuff muscles on axial CT images has been widely replaced by assessment on parasagittal acquired magnetic resonance images. This change raised 2 important questions. First, there is a controversy whether the Goutallier classification can simply be adopted for magnetic resonance imaging. The second question is whether the muscle assessment in the axial plane is interchangeable with that in the parasagittal plane. We hypothesize that the assessment of fatty muscle infiltration is the same on reformatted parasagittal CT images as on axial CT images METHODS: Three independent readers, 2 radiologists and one shoulder surgeon, rated fatty changes of the supraspinatus muscle on CT scans of 91 shoulders. Goutallier grades were assessed on axial and reformatted parasagittal CT images in 2 separate reading sessions. The paired t test was used to find differences between grading results on axial and reformatted parasagittal images. The Pearson correlation coefficient and weighted kappa statistics were used to quantify linear correlation, intrareader, and interreader agreement. RESULTS: Mean (SD) Goutallier grading among all readers was 0.80 (1.16) (range, 0-4) on axial images and 0.89 (1.05) (range, 004) on parasagittal reconstructions. We detected a trend toward a slightly higher Goutallier grading on parasagittal reconstructions; however, this result was not significant (P = 0.07). The Pearson correlation coefficient was 0.702 (P < 0.001). Weighted kappa statistics indicated a moderately good to good intrareader (range of weighted kappa, 0.53-0.62) and interreader (weighted kappa, axial images, 0.55; reformatted parasagittal images, 0.65) agreement. CONCLUSION: Grading of fatty infiltration of the supraspinatus muscle on parasagittal CT images is comparable with the standard Goutallier grading on axial images and is characterized by a moderately good to good intrareader and interreader agreement. Assessment of parasagittal images is characterized by a slightly higher interreader agreement and may therefore be the preferable modality.

Hip MRI: how useful is intraarticular contrast material for evaluating surgically proven lesions of the labrum and articular cartilage?

OBJECTIVE: The objective of our study was to prospectively compare the diagnostic performance of MR arthrography and conventional MRI with surgical correlation in the same patient for detecting labrum and articular cartilage defects. SUBJECTS AND METHODS: Twenty-eight patients (mean age, 31.8 years) underwent MR arthrography, conventional MRI, and subsequent hip surgery, which served as the reference standard. Labrum and cartilage defects were evaluated at MRI by two independent readers. A McNemar test and kappa statistics were used for statistical analysis. RESULTS: At surgery, 31 labral tears were identified. MR arthrography had an advantage over conventional MRI for detecting labral tears at the anterosuperior quadrant (sensitivity of MR arthrography, 81% and 69% for readers 1 and 2, respectively; sensitivity of conventional MRI, 50% for both readers); this difference in performance between MR arthrography and conventional MRI was statistically significant for reader 1 (p = 0.02) but not for reader 2 (p = 0.2). Interobserver agreement for labral tears was higher for MR arthrography (κ = 0.81) than for conventional MRI (κ = 0.63). Surgery showed 31 acetabular cartilage defects and nine femoral cartilage defects. MR arthrography had an advantage over conventional MRI for detecting acetabular cartilage defects (sensitivity of MR arthrography, 71% and 92% for readers 1 and 2, respectively; sensitivity of conventional MRI, 58% and 83%), whereas there was no advantage to using MR arthrography for detecting femoral cartilage defects with statistically significant difference for the acetabular cartilage or femoral cartilage. Interobserver agreement was slightly higher for MR arthrography (κ = 0.50) than for conventional MRI (κ = 0.40) for assessing the acetabular cartilage and was almost identical for the femoral cartilage (κ = 0.62 and 0.63, respectively). CONCLUSION: MR arthrography was superior to conventional MRI for detecting labral tears and acetabular cartilage defects and showed a higher interobserver agreement. For femoral cartilage lesions, both modalities yielded comparable results.

Diagnostic performance of MRI measurements to assess hindfoot malalignment. An assessment of four measurement techniques.

OBJECTIVE: To investigate the ability of coronal non-weight-bearing MR images to discriminate between normal and abnormal hindfoot alignment. METHODS: Three different measurement techniques (calcaneal axis, medial/lateral calcaneal contour) based on weight-bearing hindfoot alignment radiographs were applied in 49 patients (mean, 48 years; range 21-76 years). Three groups of subjects were enrolled: (1) normal hindfoot alignment (0°-10° valgus); (2) abnormal valgus (>10°); (3) any degree of varus hindfoot alignment. Hindfoot alignment was then measured on coronal MR images using four different measurement techniques (calcaneal axis, medial/lateral calcaneal contour, sustentaculum tangent). ROC analysis was performed to find the MR measurement with the greatest sensitivity and specificity for discrimination between normal and abnormal hindfoot alignment. RESULTS: The most accurate measurement on MR images to detect abnormal hindfoot valgus was the one using the medial calcaneal contour, reaching a sensitivity/specificity of 86 %/75 % using a cutoff value of >11° valgus. The most accurate measurement on MR images to detect abnormal hindfoot varus was the sustentaculum tangent, reaching a sensitivity/specificity of 91 %/71 % using a cutoff value of <12° valgus. CONCLUSION: It is possible to suspect abnormal hindfoot alignment on coronal non-weight-bearing MR images. KEY POINTS: • Abnormal hindfoot alignment can be identified on coronal non-weight-bearing MR images. • The sustentaculum tangent was the best predictor of an abnormally varus hindfoot. • The medial calcaneal contour was the best predictor of a valgus hindfoot.

Closed suction drainage with or without re-transfusion of filtered shed blood does not offer advantages in primary non-cemented total hip replacement using a direct anterior approach.

INTRODUCTION: Wondering if the use of drains allowing re-transfusion of shed blood as opposed to closed suction drains or no drains would improve quality of care to patients undergoing simple non-cemented primary total hip replacement (THR) using a direct anterior approach, a three-arm prospective randomized study was conducted. METHOD: One hundred and twenty patients were prospectively randomized to receive no drain, closed suction drains or drains designed for re-transfusion of shed blood. Blood loss, VAS pain scores, thigh swelling, hematoma formation, number of dressings changed and hospital stay were compared and patients followed for 3 months. RESULTS: Drains did not have any significance on postoperative haemoglobin and haematocrit levels or homologous blood transfusion rates. Patients receiving homologous blood transfusions had too small drain volumes to benefit from re-transfusion and patients, who get drained fluid re-transfused, were far away from being in need of homologous blood transfusion. Omitting drains resulted in more thigh swelling accompanied with a tendency of slightly more pain during the first postoperative day but without effect on clinical and radiological outcome at 3 months. Earlier dry operation sites resulting in simplified wound care and shorter hospital stay was encountered when no drain was used. CONCLUSION: The possibility to re-transfuse drained blood was not an argument for using drains and, accepting more thigh swelling, we stop to use drains in simple non-cemented primary THR using the direct anterior approach.

Hindfoot alignment measurements: rotation-stability of measurement techniques on hindfoot alignment view and long axial view radiographs.

OBJECTIVE: The purpose of this article is to identify the most rotation-stable hindfoot alignment measurement techniques on hindfoot alignment view and long axial view radiographs. MATERIALS AND METHODS: Hindfoot alignment was quantified on hindfoot alignment view and long axial view radiographs of a phantom in different rotation positions. Rotation stability of measurements using the calcaneal axis, the medial and lateral calcaneal contour, and the apparent moment arm were graphically compared. Interreader agreement was quantified using intraclass correlation coefficient. RESULTS: On hindfoot alignment view radiographs, measurements using the medial and lateral calcaneal contour were rotation stable (± 5°). Measurements using the calcaneal axis were not reliable and showed considerable divergence with phantom rotation. Measurements using the apparent moment arm manifested an almost linear relationship to phantom rotation. On long axial view radiographs, all measurements manifested an almost linear relationship to phantom rotation, whereas those using the calcaneal axis were the most rotation stable. Interreader agreement of all measurement techniques was perfect on both hindfoot alignment and long axial view radiographs (intraclass correlation coefficient, 0.8-0.98; p < 0.001). Interreader agreement was slightly better on long axial view radiographs. CONCLUSION: Hindfoot alignment measurements should be performed on hindfoot alignment view radiographs using the medial or lateral calcaneal contour or on long axial view radiographs using the calcaneal axis. Interreader agreement of hindfoot alignment measurements is slightly better on long axial view radiographs than on hindfoot alignment view radiographs.

Is the internal rotation lag sign a sensitive test for detecting hip abductor tendon ruptures after total hip arthroplasty?

INTRODUCTION: Total hip arthroplasty (THA) is one of the most frequently performed procedures in orthopaedics and weakness of external rotators is often recognized thereafter. However, the etiology of lateral hip pain is multifaceted. For the diagnosis of abductor tendon rupture, magnetic resonance imaging (MRI) is the gold standard. As not every patient can be subjected to MRI, a clinical diagnostic test for easy detection of lesions of the abductor tendon is missing. Here, we present the internal rotation lack sign indicating abductor tendon pathology. METHODS: The patient is placed in lateral position on a stretcher with hips and knees in neutral position. The knee is flexed to 45° and the hip passively abducted and elevated by the investigator. With the foot passively abducted, the patient is then asked to bring his knee in direction to the examination table. This motion is also tested passively. The test is regarded positive, if no internal rotation is possible and/or if this is painful. If groin pain is elicited during either of the exercises, the test is also rated positive. RESULTS: We evaluated this test in 20 patients clinically and by magnetic resonance imaging (MRI). All patients demonstrated a positive internal rotation lag sign. Twelve of them lag of internal rotation and evidence of anterior abductor tendon rupture on MRI, 8 with lag of internal rotation and no evidence of abductor tendon rupture. CONCLUSION: The new clinical diagnostic sign presented here may improve the diagnosis of abductor tendon rupture in the future. LEVEL OF EVIDENCE: Diagnostic study, level I.

Detection and quantification of glenohumeral joint effusion: reliability of ultrasound.

OBJECTIVES: To evaluate reliability of ultrasound for detection and quantification of glenohumeral joint effusion. METHODS: With institutional review board approval and informed consent ultrasound of 30 consecutive patients before and after MR arthrography of the shoulder was performed. Presence and width of any anechoic collection was noted within various locations (biceps tendon sheath, subscapular recess (neutral position and internal rotation), posterior glenohumeral joint recess (neutral position and external rotation)). Injected fluid (8-12 ml) into the glenohumeral joint served as gold-standard. Widths of anechoic collections were correlated (Spearman rank correlation) with injected fluid. RESULTS: Glenohumeral anechoic collection was consistently seen in the posterior glenohumeral joint recess with the arm in external rotation (100%, 30/30), and in the biceps tendon sheath (97%, 29/30). Ultrasound was not sensitive at other locations (7%-17%). Mean width in anterior-posterior direction of anechoic collection in the posterior glenohumeral joint recess was 7 mm (range: 3-18 mm), 2 mm (range: 1-7 mm) in the biceps tendon sheath. Significant correlation (R = 0.390, p = 0.033) was found between width of anechoic collection and injected fluid in the posterior glenohumeral joint recess. CONCLUSIONS: Glenohumeral joint effusion can be detected and quantified most reliably in the posterior glenohumeral joint recess with the arm in external rotation.

CT-guided sternoclavicular joint injections: description of the procedure, reliability of imaging diagnosis, and short-term patient responses.

OBJECTIVE: The purpose of this study was to evaluate pain relief 20 to 30 minutes after diagnostic or therapeutic injections into the sternoclavicular joint and to compare patient outcomes based on the CT diagnosis. MATERIALS AND METHODS: Informed consent was obtained from each patient. Ethics approval was not required. Fifty patients who had CT-guided injections of corticosteroid and local anesthetic into their sternoclavicular joints were included in the study. Preinjection and 20- to 30-minute postinjection visual analog scale data were recorded and compared with the imaging findings agreed by consensus. Kappa statistics were calculated for the reliability of imaging diagnosis. The percentage of patients improving after joint injection was calculated, and the risk ratio comparing the response of patients with osteoarthritis to those without osteoarthritis was completed. The correlation between the severity of each patient's osteoarthritis and the pain response was calculated using Spearman's correlation coefficient. RESULTS: Sixty-six percent of the patients reported clinically significant pain reduction at between 20 and 30 minutes after injection. The proportion of patients with osteoarthritis who had a clinically significant response was 67% compared with 64% for patients who did not have osteoarthritis. This difference was not statistically or clinically significant. There was no correlation between the severity of osteoarthritis and the amount of pain reduction (r = 0.03). The reliability of imaging diagnosis was substantial. CONCLUSION: Two thirds of patients having sternoclavicular joint injections of corticosteroids and local anesthetics report clinically significant improvement regardless of the abnormalities detected on their CT images.

Are radiographic trochanteric surface irregularities associated with abductor tendon abnormalities?

PURPOSE: To assess the association between trochanteric surface irregularities seen on conventional radiographs and magnetic resonance (MR) evidence of abductor tendon abnormalities. MATERIALS AND METHODS: A total of 150 consecutive patients were evaluated in this retrospective study (age range, 21-88 years; mean age, 58.7 years ± 16.1 [standard deviation]; 57 men, 93 women). Because patients' rights are protected by a procedure in which they are asked to provide general approval for their records and images to be reviewed for scientific purposes, specific approval by the institutional review board was not required. Two readers independently analyzed conventional radiographs and MR images of the hip. Trochanteric surface was graded on conventional radiographs as normal, osseous irregularities extending 1-2 mm, or osseous irregularities extending more than 2 mm. On MR images, the gluteus minimus and gluteus medius tendons were classified as normal or as having tendinopathy or a partial- or full-thickness tear. Logistic regression analysis and the Fisher exact test were used for statistical analysis. Sensitivity, specificity, accuracy, positive and negative predictive values, and positive likelihood ratio were calculated. To assess interobserver agreement, a κ statistic was used. RESULTS: The positive predictive value of surface irregularities larger than 2 mm for MR tendinopathy or a partial- or full-thickness tear was 90% (37 of 41 patients). The sensitivity of radiographic changes was 40%; the specificity, 94%; the accuracy, 61%; the negative predictive value, 49%; and the positive likelihood ratio, 5.8. Interobserver agreement for detection of trochanteric surface irregularities on conventional radiographs ranged from 0.28 to 0.76. CONCLUSION: Pronounced (>2 mm) surface irregularities of the greater trochanter on conventional radiographs were associated with abductor tendon MR abnormalities.

Do patients with structural abnormalities of the shoulder experience pain after MR arthrography of the shoulder?

PURPOSE: To assess the pain course after intraarticular injection of a gadolinium-containing contrast material admixed with anesthetic for magnetic resonance (MR) arthrography of the shoulder in relation to internal derangements of the shoulder. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained for this study. The study sample consisted of 655 consecutive patients (249 female, 406 male; median age, 54 years) referred for MR arthrography of the shoulder. Pain level was measured at baseline, directly after intraarticular injection of the gadolinium-containing contrast material admixed with anesthetic, 4 hours after injection, 1 day (18-30 hours) after injection, and 1 week (6-8 days) after injection with a visual analog scale (range, 0-10). MR arthrography was used to assess the following internal derangements: lesions of the rotator cuff tendons and long biceps tendon, adhesive capsulitis (frozen shoulder), fluid in the subacromial bursa, labral tears, and osteoarthritis of the glenohumeral joint. History of shoulder surgery was recorded. Linear regression models were calculated for the dependent variable (difference between follow-up pain and baseline pain), with the independent variable grouping adjusted for age and sex. RESULTS: There was no significant association between pain level over time and internal derangements of the shoulder, nor was there significant association between pain level over time in patients with a history of shoulder surgery and patients without a history of shoulder surgery. CONCLUSION: Neither internal derangements nor prior surgery have an apparent effect on the pain course after MR arthrography of the shoulder.

Ligaments and plicae of the elbow: normal MR imaging variability in 60 asymptomatic subjects.

PURPOSE: To prospectively evaluate the normal variability of ligaments, plicae, and the posterior capitellum on conventional magnetic resonance (MR) images of the elbow in asymptomatic volunteers. MATERIALS AND METHODS: The study was approved by the institutional ethics board, and informed consent was obtained from all subjects. MR imaging was performed at 1.5 T in 60 asymptomatic volunteers (30 women, 30 men; age range, 22-51 years; median age, 32.8 years) by using the following five pulse sequences: transverse T1-weighted spin-echo, sagittal T2-weighted fast spin-echo, coronal fast spin-echo short-inversion-time inversion recovery, transverse intermediate-weighted with fat saturation, and coronal three-dimensional water-excitation true fast imaging with steady-state precession. The visibility (completely visible over the entire course, partially visible, or not visible) and signal intensity characteristics (hypointense or hyperintense to muscle, homogeneous signal intensity vs striation) of the elbow ligaments and plicae were evaluated by three independent readers. The presence of pseudodefects at the posterior capitellum was determined. The dimensions of all structures were measured by two independent readers. RESULTS: The anterior ulnar collateral ligament (UCL) and radial collateral ligament (RCL) were visible over their entire course in all 60 subjects (100%). The posterior UCL, lateral UCL, and annular ligament (AL) were completely visible in 58 (97%), 51 (85%), and 59 (98%) of the 60 subjects, respectively, and partially visible in the remaining subjects. Increased signal intensity with fluid-sensitive sequences was found in the anterior UCL in nine of the 60 subjects (15%), posterior UCL in four subjects (7%), RCL in one subject (2%), lateral UCL in six subjects (10%), and AL in one subject (2%). The median thickness and 90th percentile were 2.5 and 3.5 mm, respectively, for the anterior UCL, 1.0 and 1.7 mm for the posterior UCL, 1.9 and 2.8 mm for the RCL, 2.3 and 3.8 mm for the lateral UCL, and 1.0 and 1.3 mm for the AL. A posterolateral plica (median dimension, 4.3 × 1.9 × 3.9 mm) was found in 59 of the 60 subjects (98%), whereas a posterior plica (median dimension, 1.8 × 1.4 mm) could be detected in only 20 (33%). A pseudodefect of the capitellum was noted in 51 of the 60 subjects (85%). CONCLUSION: The elbow ligaments and the posterolateral plica are consistently visible on conventional MR images of asymptomatic subjects. Most normal ligaments are thinner than 4 mm, and most plicae are thinner than 3 mm.

Postoperative MR imaging of the foot and ankle: tendon repair, ligament repair, and Morton's neuroma resection.

This review article describes the postoperative magnetic resonance (MR) findings relating to surgery after tendon repair, ligament repair, and Morton's neuroma resection. The normal postoperative tendon is commonly thickened, showing signal changes that are most pronounced 3 to 6 months after surgery. Two years after tendon suture, the signal intensity should be low on T2-weighted images. The focus of the postoperative MR imaging after ankle repair is to detect the normal condition after the various surgical procedures (e.g., Broström, Watson-Jones, Evans, or Chrisman-Snook). The repaired ligament has to be visible, low signal intense on T2-weighted MR images, and the shape should be homogeneous. A high rate (26%) of so-called Morton's neuroma recurrences is seen in asymptomatic individuals after Morton's neuroma resection. Postoperatively, intermetatarsal bursitis MR abnormalities are more commonly encountered in symptomatic intermetatarsal spaces than in asymptomatic intermetatarsal spaces.

Morton neuroma: MR imaging after resection--postoperative MR and histologic findings in asymptomatic and symptomatic intermetatarsal spaces.

PURPOSE: To evaluate the prevalence of postoperative magnetic resonance (MR) imaging findings in asymptomatic and symptomatic patients after resection of Morton neuroma. MATERIALS AND METHODS: This study was approved by the institutional review board. Informed consent was obtained from each participant. Fifty-eight consecutive patients (46 women, 12 men) who had undergone resection of a painful Morton neuroma (90 Morton neuromas were removed in 66 feet), pre- and postoperative MR imaging, and clinical follow-up for a minimum of 2 years after surgery were identified. Two experienced musculoskeletal radiologists evaluated MR images with regard to the presence of presumed recurrent Morton neuroma, scar, or intermetatarsal bursitis. The prevalence of abnormalities in asymptomatic and symptomatic intermetatarsal spaces was determined. The results of the second radiologist were used only to determine interobserver reliability. The kappa statistics were obtained to assess interobserver agreement. Seven patients with presumed recurrent Morton neuroma underwent repeat surgery. RESULTS: Clinically speaking, 68 intermetatarsal spaces (44 of 58 patients [76%], 47 feet) were asymptomatic at follow-up and 22 (14 of 58 patients [24%], 19 feet) were symptomatic. A presumed Morton neuroma was found in 18 (26%) of the asymptomatic spaces and 11 (50%) of the symptomatic spaces. A presumed scar was found in six (9%) of the asymptomatic spaces and two (9%) of the symptomatic spaces. A presumed intermetatarsal bursitis was found in six (9%) of the asymptomatic spaces and six (27%) of the symptomatic spaces. Interobserver agreement for presumed recurrent Morton neuroma was substantial (kappa = 0.64). Histologic examination of presumed recurrent Morton neuroma revealed fibrous tissue but no sign of peripheral neural tissue. CONCLUSION: MR imaging after Morton neuroma resection commonly reveals Morton neuroma-like abnormalities in asymptomatic and symptomatic intermetatarsal spaces.

Elbow stiffness: effectiveness of conventional radiography and CT to explain osseous causes.

OBJECTIVE: The purpose of our study was to evaluate the effectiveness of conventional radiography and CT for explaining the osseous causes of elbow stiffness. MATERIALS AND METHODS: Two independent readers analyzed loose bodies and osteophytes on conventional radiography and CT (or CT arthrography) of the elbow in 94 consecutive patients (71 men, 23 women; mean age, 41 years; range, 18-68 years). Arthroscopic or surgical correlation was available in 58 (62%) patients. In all 94 patients, the expected restriction of motion was measured on images and correlated (Pearson's correlation) with the clinical restriction of motion. Kappa statistics were performed for interobserver agreement. RESULTS: Accuracy for detecting loose bodies was 67% with conventional radiography and 79% with CT. Differences in accuracy were most pronounced for detecting loose bodies in the posterior joint space (64% for conventional radiography vs 79% for CT). Accuracy for detecting osteophytes was 69% with conventional radiography and 76% with CT. Expected restriction of motion on conventional radiography correlated significantly with clinical restriction for only one reader for flexion (R = 0.21, p = 0.04). Expected restriction of extension on CT correlated significantly with clinical restriction of motion by both readers (R = 0.34 and 0.33, p = 0.001 and 0.001, respectively). Expected restriction of flexion on CT correlated significantly by one reader (R = 0.24, p = 0.02). Interobserver agreement with regard to detection of both loose bodies and osteophytes was higher for CT (kappa = 0.83 and 0.76) than for conventional radiography (0.64 and 0.60). CONCLUSION: CT is more effective than conventional radiography in explaining the osseous causes of elbow stiffness.

Articular cartilage and labral lesions of the glenohumeral joint: diagnostic performance of 3D water-excitation true FISP MR arthrography.

OBJECTIVE: To evaluate the diagnostic performance of MR arthrography in the detection of articular cartilage and labral lesions of the glenohumeral joint using a transverse 3D water-excitation true fast imaging with steady-state precession (FISP) sequence. MATERIALS AND METHODS: Seventy-five shoulders were included retrospectively. Shoulder arthroscopy was performed within 6 months of MR arthrography. MR images were evaluated separately by two radiologists. They were blinded to clinical and arthroscopic information. Arthroscopy served as the reference standard. RESULTS: For the detection of humeral cartilage lesions, sensitivities and specificities were 86% (12/14)/89% (50/56) for observer 1 and 93%/86% for observer 2) for the transverse true FISP sequence and 64%/86% (50%/82% for observer 2) for the coronal intermediate-weighted spin-echo images. The corresponding values for the glenoidal cartilage were 60% (6/10)/88% (51/58) (80%/76% for observer 2) and 70%/86% (60%/74% for observer 2) respectively. For the detection of abnormalities of the anterior labrum (only assessed on true FISP images) the values were 94% (15/16)/84% (36/43) (88%/79% for observer 2). The corresponding values for the posterior labrum were 67% (8/12)/77% (36/47) (observer 2: 25%/74%). The kappa values for the grading of the humeral and glenoidal cartilage lesions were 0.81 and 0.55 for true FISP images compared with 0.49 and 0.43 for intermediate-weighted fast spin-echo images. Kappa values for true FISP evaluation of the anterior and posterior part of the labrum were 0.81 and 0.70. CONCLUSION: Transverse 3D true FISP MR arthrography images are useful for the difficult diagnosis of glenohumeral cartilage lesions and suitable for detecting labral abnormalities.