Comparison of Asymptomatic and Symptomatic Adverse Local Tissue Reaction in Patients With Head-Neck Taper Corrosion.

BACKGROUND: Diagnosis of adverse local tissue reaction (ALTR) in metal-on-polyethylene (MoP) total hip arthroplasty (THA) secondary to head-neck taper corrosion is challenging. The purpose of this study is to compare differences between asymptomatic and symptomatic ALTR in an observational cohort, including presentation, metal ion differences, and metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) findings. METHODS: We performed a retrospective review of an observational cohort of 492 MoP THA patients at increased risk of developing ALTR. Ninety-four patients underwent revision arthroplasty for ALTR. Patients were stratified into symptomatic and asymptomatic ALTR groups. Presentation, metal ion levels, and imaging findings were compared. RESULTS: For patients with confirmed ALTR, 41% were asymptomatic. There was a statistically significant difference in the serum chromium levels between symptomatic and asymptomatic ALTR patients (2.2 µg/L vs 3.1 µg/L, P = .05). There was no statistically significant difference between the serum cobalt levels or MRI findings in these 2 groups. We observed that extracapsular disease associated with ALTR could be misinterpreted as trochanteric bursitis. CONCLUSION: Almost half of the MoP THA ALTR cases identified were asymptomatic. Cobalt levels could not differentiate between symptomatic and asymptomatic pseudotumor formation. Symptomatic and asymptomatic MoP ALTRs have similar MARS MRI characteristics. Our findings suggest that it is essential to risk stratify patients who could potentially have ALTR based on implant type, symptoms, ion levels, and MARS MRI.

Labral Morphology and Number of Preoperative Dislocations Are Associated With Recurrent Instability After Arthroscopic Bankart Repair.

PURPOSE: To develop a method to measure capsule and labral volume on preoperative magnetic resonance imaging to predict surgical failure after primary Bankart repair. METHODS: A retrospective case-control study was conducted on patients undergoing primary anterior arthroscopic shoulder stabilization. Surgical failure was defined as a recurrent dislocation event. Cases were matched to controls based on age and sex in a 1:2 ratio. Preoperative magnetic resonance (MR) arthrograms were analyzed by 2 trained reviewers using Vitrea software to measure labral and capsular volume with a 3-dimensional model. Labral size was also qualitatively measured on axial images. A "diffusely small" labrum was defined as labral height less than the width of the glenoid tidemark cartilage. RESULTS: Of the 289 patients who had an arthroscopic Bankart repair from 2006 to 2015, 33 who had a postoperative dislocation met the inclusion criteria and were matched to 62 control patients who did not. There was no difference between groups with regard to age (P = .88), sex (P = .82), contact sport participation (P = .79), proportion of overhead athletes (P = .33), proportion of throwers (P = 1), surgical positioning in lateral decubitus (P = .18), or number of repair anchors used (P = .91). The average number of preoperative dislocations was significantly higher in the failure group (3.2 vs. 2.0, P < .0001). In patients with normal labrum morphology, the odds of having surgical failure increased by 26% for a 1-unit increase in the number of prior dislocations (odds ratio [OR] 1.26, 95% confidence interval [CI] 1.02 to 1.55). The case and control groups had similar labral and capsular volume as measured in Vitrea. The failure group had a significantly higher proportion of patients with a diffusely small labral morphology (47% vs. 17%, P = .03). Controlling for number of preoperative dislocations, the odds of having a diffusely small labral morphology was 3.2 times more likely in the case group than the control group (95% CI 1.259 to 8.188). Interrater reliability between 2 independent reviewers was excellent for measurement of capsule volume (r = 0.91) and good for measurement of labral volume (r = 0.74). CONCLUSIONS: This study presents a novel method of measuring labral and capsule volume with high interrater reliability. An increased number of recurrent dislocations prior to primary Bankart repair was associated with increased odds of recurrent instability after surgery. The OR for failure also increased with increasing number of preoperative dislocations. Diffusely small labral morphology was associated with having a postoperative redislocation. LEVEL OF EVIDENCE: III (case-control study).

Effect of patient age on accuracy of primary MRI signs of long head of biceps tearing and instability in the shoulder: an MRI-arthroscopy correlation study.

OBJECTIVE: To determine the effect of patient age on the accuracy of primary MRI signs of long head of biceps (LHB) tendon tearing and instability in the shoulder using arthroscopy as a reference standard. MATERIALS AND METHODS: Subjects with MRI studies and subsequent arthroscopy documenting LHB tendon pathology were identified and organized into three age groups (18-40, 41-60, 61-87). Normal and tendinopathic tendons were labeled grade 0, partial tears grade 1 and full tears grade 2. Two radiologists blinded to arthroscopic data graded MRI studies independently. Prevalence of disease, MRI accuracy for outcomes of interest, and inter-reader agreement were calculated. RESULTS: Eighty-nine subjects fulfilled inclusion criteria with 36 grade 0, 36 grade 1 and 17 grade 2 tendons found at arthroscopy. MRI sensitivity, regardless of age, ranged between 67-86% for grade 0, 72-94% for grade 1 and 82-94% for grade 2 tendons. Specificity ranged between 83-96% for grade 0, 75-85% for grade 1 and 99-100% for grade 2 tendons. MRI accuracy for detection of each LHB category was calculated for each age group. MRI was found to be least sensitive for grade 0 and 1 LHB tendons in the middle-aged group with sensitivity between 55-85% for grade 0 and 53-88% for grade 1 tendons. Agreement between MRI readers was moderate with an unweighted kappa statistic of 62%. CONCLUSION: MRI accuracy was moderate to excellent and agreement between MRI readers was moderate. MRI appears to be less accurate in characterizing lower grades of LHB tendon disease in middle-aged subjects.

Nature abhors a vacuum: bilateral prominent rotator cable in bilateral congenital absence of the long head of the biceps tendon.

Bilateral agenesis of the long head of the biceps tendon is an exceedingly rare anomaly and can be a challenging diagnostic dilemma whose differential diagnosis includes tear. We present the third case of bilateral agenesis of the long head of the biceps tendon. Absent or shallow intertubercular sulcus is a constant finding and serves to differentiate this entity from tear. Our case is unique in that there was a radial ray anomaly, where prior reports of bilaterality did not demonstrate associated congenital anomalies. We also describe the newly reported finding of thickening of the rotator cable without the presence of rotator cuff tear. Thickening of the rotator cable may be an associated finding with agenesis of the biceps tendon.

Relationship between bone bruise volume and the presence of meniscal tears in acute anterior cruciate ligament rupture.

PURPOSE: To determine whether there is a relationship between the size of the bone bruise volume after an acute anterior cruciate ligament (ACL) rupture and the presence of meniscal tears in the medial and lateral compartment. METHODS: Following Institutional Review Board approval, 50 patients with an acute ACL rupture and MRI imaging within 30 days of injury were identified. Two musculoskeletal radiologists evaluated the lateral and medial menisci and graded them as one of the following: no meniscal tear, tear of one meniscus (medial or lateral) or tear of both menisci (medial and lateral). Sagittal T2 fat-suppressed images were used to calculate bone bruise volume. The relationship between bone bruise volume and the presence of a meniscus tear was calculated. RESULTS: Forty-three (86%) patients had a bone bruise, 16 (32%) patients had no tear, 7 (14%) patients had lateral meniscus tear, 13 (26%) patients had medial tear and 14 (28%) patients had medial and lateral tears. There was a statistically significant difference in femoral bone bruise volume when comparing no meniscal tear to medial and lateral tears as well as when comparing medial or lateral tears to medial and lateral tears. CONCLUSION: There is a statistically significant relationship between femoral bone bruise volume and the presence of meniscal tears in ACL injury, especially in the setting of medial and lateral pathology. LEVEL OF EVIDENCE: Retrospective cohort study, Level III.

Predictors of Adverse Local Tissue Reaction in a High-Risk Population.

BACKGROUND: Adverse local tissue reaction (ALTR) is a recognized complication of total hip arthroplasty (THA) with metal-on-polyethylene (MoP) bearing surface implants. Specific models of THA implants have been identified as having a higher incidence of ALTR. The purpose of this study is to determine if serum metal levels, patient symptoms, implant factors, and imaging findings can be predictive of ALTR within this high-risk population. METHODS: We retrospectively reviewed an observational cohort of 474 patients who underwent MoP THA and were at increased risk of having ALTR. Patients were stratified based on the presence or absence of ALTR. Patient symptoms, serum metal ions, implant head offset, and imaging findings were compared. RESULTS: Patients with ALTR were more likely to be symptomatic (52.9% vs 9.9%, P < .0001). The presence of ALTR was associated with significantly higher serum cobalt and chromium levels (6.2 ppb vs 3.6 ppb, P < .0001; 2.3 ppb vs 1.2 ppb, P < .0001). Head offsets greater than 4 mm were associated with a higher prevalence of ALTR (53% vs 38%, P = .05). On metal artifact reduction sequence magnetic resonance imaging, patients with ALTR had larger effusions (4.7 cm vs 2.1 cm, P < .001) and a higher incidence of trochanteric bursitis (47% vs 16%, P < .001). CONCLUSIONS: In high-risk MoP implants, serum cobalt and chromium levels are elevated, even in patients without ALTR. A larger femoral head offset is a risk factor for the development of ALTR. Our study suggests that patients presenting with painful THA and elevated metal ions require risk stratification based on patient symptoms, metal artifact reduction sequence magnetic resonance imaging findings, and implant factors.

Musculoskeletal applications of platelet-rich plasma: fad or future?

OBJECTIVE: The purpose of this article is to detail the biology of platelet-rich plasma (PRP), critically review the existing literature, and discuss future research applications needed to adopt PRP as a mainstay treatment method for common musculoskeletal injuries. CONCLUSION: Any promising minimally invasive therapy such as PRP deserves further investigation to avoid surgery. Diagnostic imaging outcome assessments, including ultrasound-guided needle precision, should be included in future investigations.

Glenoid Radius of Curvature and Humeral Head Volume Are Associated With Postoperative Dislocation After Arthroscopic Bankart Repair.

PURPOSE: To measure bony morphologic parameters and identify their association with arthroscopic Bankart repair failure. METHODS: This was a retrospective comparative study. The inclusion criteria were primary arthroscopic Bankart repair, no prior shoulder surgery, traumatic cause, and had a Bankart (soft tissue and bony) lesion evident on magnetic resonance imaging (MRI). The exclusion criteria were posterior labral pathology, multidirectional instability, connective tissue disorder, rotator cuff pathology, and those who underwent concomitant shoulder procedures. Patients who had a postoperative redislocation (unstable group) were compared with matched patients who did not (stable group). Data were obtained by chart review and from preoperative MRI. Comparisons were made using the Student t test, Fisher exact test, or χ2 test. Statistical significance was defined as P < .05. Inter-rater reliability was measured between reviewers. RESULTS: A total of 45 patients experienced a postoperative dislocation and were matched to 90 patients without a postoperative dislocation. There were no differences in demographic and radiographic variables. The radius of curvature (ROC) of the glenoid was larger (shallower) in the unstable group (23.6 mm vs 22.6 mm, P = .05). The humeral head volume (HHV) trended higher in the unstable group (68.9 mL vs 62.9 mL, P = .06). The glenoid volume was not significantly different. A greater percentage of patients with a glenoid ROC of 24.5 mm or greater (62.1% vs 26.4%, P = .0003) and an HHV of 80 mm3 or greater (60.8% vs 28.9%, P = .003) experienced a redislocation compared with patients without these factors. Patients with a glenoid ROC of 24.5 mm or more and an HHV of 80 mm3 or more had greater than 4 times the odds of redislocation (odds ratio, 4.56; 95% confidence interval, 1.44-14.43; P = .0098). Strong inter-rater reliability was found for the HHV, glenoid volume, glenoid ROC, and humeral head ROC measurements (r = 0.94, r = 0.88, r = 0.89, and r = 0.95, respectively). CONCLUSIONS: This study shows that large ROC (shallow) glenoids in conjunction with large humeral heads may predispose patients to failure after arthroscopic Bankart repair. LEVEL OF EVIDENCE: Level III, retrospective comparative trial.

Magnetic resonance appearance of posterosuperior labral peel back during humeral abduction and external rotation.

OBJECTIVE: To describe the magnetic resonance appearance of posterosuperior labral peel back and determine the reliability of MR in the abducted and externally rotated (ABER) position for the prospective diagnosis of arthroscopically proven cases of posterosuperior labral peel back. METHODS: After approval by the institutional review board (IRB) of the University of Pittsburgh Medical Center, USA, databases of patients who underwent arthroscopy over a 2-year period for one of three clinical diagnoses [suspected type 2 superior labrum anterior to posterior (SLAP) tears, posterior instability, or multidirectional instability] were reviewed after anonymization by an honest broker. Sixty-three cases were selected by the following inclusion criteria: operative report documenting labral peel back in the ABER position, age <40 years, and preceding MR arthrogram evaluations with images in the ABER position (n=34). Inclusion criteria for the control group differed from those for the case group insofar as the operative note documented the absence of posterosuperior labral peel back (n=29). Cases and controls were randomized in one list and evaluated independently by two fellowship-trained musculoskeletal radiologists unaware of the surgical results and using a three-point grading system (0 = posterosuperior labrum normally positioned lateral/craniad to glenoid articular plane in ABER; 1 = posterosuperior labral tissue flush with the glenoid articular plane in ABER; 2 = posterosuperior labral tissue identified medial/caudal to glenoid articular plane in ABER). Only one image in ABER showing abnormal posterosuperior labral position was required for a grade of 1 or 2 to be assigned. Sensitivity, specificity, and positive and negative predictive value were calculated as well as the level of agreement between readers (kappa). RESULTS: Both readers assigned a grade of 2 to 25 of 34 patients with surgically proven labral peel back. Of the patients with surgically proven SLAP tears with peel back in ABER, reader A assigned a grade of 1 to seven patients and a grade of 0 to two patients, while reader B assigned a grade of 1 to eight patients and a grade of 0 to one patient. In the control group of 29 patients, reader A assigned 28 patients a grade of 0, one patient a grade 1, and no patients a grade 2. Reader B assigned 27 patients a grade of 0, two a grade 1, and no patients a grade 2. After the data had been dichotomized, with grade 1 and 0 cases both being regarded as negative, the MR criteria showed a sensitivity of 73%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 78%. The kappa coefficient of inter-rater agreement was excellent at 0.9, with disagreement in only four of 63 cases. In five of the 34 cases with peel back, a labral tear, defined by imbibition of contrast agent within a gap between labrum and underlying glenoid bone, could not be identified in standard planes in the neutral position. CONCLUSIONS: The use of the glenoid articular plane as a reference line to evaluate labral peel back in the abducted and externally rotated position is a fairly accurate and highly precise method for detection of posterosuperior labral peel back. Raising the possibility of labral peel back may help alert the arthroscopist to the presence of superior labral instability while the arm is abducted and externally rotated.

Indium-111 pentetreotide imaging of carcinoid tumor of the thymus.

INTRODUCTION: Carcinoid tumors are relatively rare and can occur in the thorax, abdomen, or pelvis. Indium-111 pentetreotide scanning is useful for the identification of these tumors. In this report, we present imaging findings and discussion pertaining to a 43-year-old man who presented with Cushing's syndrome resulting from a thymic carcinoid tumor. The imaging is of interest because there is not only marked uptake of In-111 pentetreotide in the thymic carcinoid tumor, but also within the adrenal glands attributable to elevated tumor-derived ACTH. METHOD: Planar and single-photon emission computed tomography (SPECT) images of the chest and abdomen were obtained 15 minutes after the injection of 6.6 mCi of In-111 pentetreotide. Further planar and SPECT images were obtained approximately 4 and 24 hours after injection of the radiopharmaceutical. Correlation of In-111 pentetreotide SPECT was made with laboratory results and CT evaluation of the chest and abdomen. RESULTS: Initial clinical workup for Cushing's syndrome included a contrast-enhanced brain magnetic resonance image that showed a small pituitary lesion thought to represent a microadenoma. Normal inferior petrosal venous sinus sampling for ACTH suggested there was an ectopic ACTH source. Subsequent CT of the chest identified a 3 x 3-cm enhancing mediastinal mass. Avid uptake within the mass on In-111 pentetreotide images suggested that the underlying cause of Cushing's syndrome was ACTH production from a thymic carcinoid. Increased uptake of In-111 pentetreotide was also noted within hyperplastic adrenal glands. Surgical resection and histologic evaluation established the diagnosis of a moderately differentiated thymic carcinoid tumor. CONCLUSION: This case illustrates the complementary ability of In-111 pentetreotide planar and SPECT imaging and CT to diagnose an ACTH-producing thymic carcinoid tumor leading to adrenal hyperplasia and Cushing's syndrome.

The effects of meniscus injury on the development of knee osteoarthritis: data from the osteoarthritis initiative.

BACKGROUND: Osteoarthritis (OA) is a leading cause of pain and disability, and the knee is one of the most commonly affected joints. Many have speculated that injury to the meniscus may play a key role in the development of knee OA; however, the exact relationship of meniscus injury and knee OA is unknown. PURPOSE: To examine the rate of meniscus injuries in patients with and without incident radiographic knee OA and to explore how the type, size, and location of the meniscus injury affects the development of OA. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A secondary case-control analysis was conducted of the Knee Osteoarthritis Initiative (OAI) database, which is a prospective, longitudinal, multicenter cohort study of knee health in patients at risk for knee OA. Eligible patients included those without radiographic OA at baseline in 1 knee. Thirty-two patients who developed radiographic OA in a previously unaffected knee after 2 years of follow-up were matched to 64 age-, sex-, and body mass index-matched patients who did not develop OA. The study analyzed the relationship between the development of OA and the presence of a meniscus tear or degenerative signal, meniscus extrusion, tear type, and size of injury on the baseline magnetic resonance imaging scans. Conditional logistic regression was used to identify significant predictors of OA. RESULTS: The rate of medial meniscus lesions (tear or degeneration) was not significantly higher in those who developed incident OA (85%) compared with the control patients (68%; P = .07). However, medial meniscus extrusion (odds ratio [OR], 3.03; 95% confidence interval [CI], 1.4-6.5), complex tears (OR, 5.0; 95% CI, 1.0-25), and tears with large radial involvement (OR, 5.92; 95% CI, 1.7-7.5) were more common at baseline in cases compared with controls. CONCLUSION: Knees with meniscus tears with greater radial involvement and extrusion are at greater risk for later development of radiographic OA.

Emerging MRI methods in rheumatoid arthritis.

New MRI techniques have been developed to assess not only the static anatomy of synovial hyperplasia, bone changes and cartilage degradation in patients with rheumatoid arthritis (RA), but also the activity of the physiological events that cause these changes. This enables an estimation of the rate of change in the synovium, bone and cartilage as a result of disease activity or in response to therapy. Typical MRI signs of RA in the pre-erosive phase include synovitis, bone marrow edema and subchondral cyst formation. Synovitis can be assessed by T2-weighted imaging, dynamic contrast-enhanced MRI or diffusion tensor imaging. Bone marrow edema can be detected on fluid-sensitive sequences such as short-tau inversion recovery or T2-weighted fast-spin echo sequences. Detection of small bone erosions in the early erosive phase using T1-weighted MRI has sensitivity comparable to CT. Numerous MRI techniques have been developed for quantitative assessment of potentially pathologic changes in cartilage composition that occur before frank morphologic changes. In this Review, we summarize the advances and new directions in the field of MRI, with an emphasis on their current state of development and application in RA.

MRI findings of prepatellar Morel-Lavallée effusions.

OBJECTIVE: To describe MR imaging characteristics and treatment options for prepatellar closed degloving injuries or Morel-Lavallée effusions. Imaging features are discussed that may aid in the distinguishing of this entity from "housemaid's knee" or prepatellar bursitis. MATERIALS AND METHODS: MR images of four young wrestlers were reviewed by two attending radiologists and one fellow, and correlative clinical data were collected using the electronic medical database. RESULTS: MR images in all cases showed a unilocular, T2 hyperintense prepatellar collection extending beyond the normal boundaries of the prepatellar bursa. No necrotic fat or blood products were identified in the collections. Surgical pathology proving the absence of synovial tissue was available for one case, and differentiation of the collection from the adjacent bursa was confirmed visually by the surgeon in a second case. CONCLUSION: Although prepatellar hemorrhagic bursitis and Morel-Lavallée effusions share many imaging features, making a specific diagnosis in most cases is not necessary, as treatment is often similar for both entities.

Los trastornos del sueno en la practica clinica / Evaluation and treatment of sleep disorders in the clinical practice

Con el fin de mejorar la atencion medica de los pacientes con problemas del sueno se presentan en esta revision las concepciones modernas sobre el mismo y se describen someramente sus principales trastornos, a saber: somnolencia excesiva diurna, insominio, parasomnias y desfases vigilia-sueno; se enfatizan la necesidad de estudiar adecuadamente los pacientes con estos trastornos y, en el caso del imsonio, la importancia de evitar la prescripcion injustificada de medicacion hipnotica

In order to improve medical care of patients with sleep disorders this review presents modern conceptions about It and briefly describes Its most frequent disorders, namely: excessive daytime somnolence, insomnia, parasomnias and disorders of sleep-wake pattern; emphasis Is made on the need to thoroughly work-up patients suffering from these disorders and to avoid unjustified hypnotic medication in cases of insomnia