Accessory anterolateral talar facet associated with tarsal coalition: prevalence and cross-sectional characterization.

OBJECTIVE: The accessory anterolateral talar facet (AALTF) is a developmental entity described as a potential cause for rigid, painful flat foot. This study evaluates the possible association between the AALTF and other flat foot etiologies, specifically different types of tarsal coalitions. MATERIALS AND METHODS: We evaluated patients with tarsal coalition or sinus tarsi syndrome for an AALTF on CT and MRI. Exclusion criteria included acute ankle trauma, recent surgery, motion or metal artifacts. We evaluated the AALTF length and height, and the lateral talocalcaneal structures for associated findings. The presence of calcaneonavicular (CNC), intra-articular middle facet talocalcaneal (MFTCC), posterior facet talocalcaneal (PFTCC), extra-articular posteromedial talocalcaneal (EATCC) and other rare coalitions were also evaluated. RESULTS: One hundred eighty-seven patients were included (age range 14-91 years; mean ± SD; 50 ± 17 years). The AALTF prevalence in the study population was 31.55% (59/187), 40.91% in men, and 23.23% in women. The AALTF average length was 4.5 ± 1.1 mm, and average height was 8.9 ± 3.4 mm. The AALTF was found to be significantly associated with lateral talocalcaneal osseous changes such as cortical thickening and cystic changes (34/59 and 24/59 respectively, P < 0.01). The AALTF was also found to be significantly associated with sinus tarsi edema on MRI (45/52, P < 0.05). The AALTF was also significantly associated with EATCC (19/59, P < 0.01) and MFTCC (7/59, P < 0.05). No significant association was found with CNC, PFTCC or other rare coalitions. CONCLUSION: The AALTF is common and significantly associated with some tarsal coalitions, specifically EATCC and MFTCC. When an AALTF or coalition is identified, special attention should be made to evaluate for other associated pathologies, as this could potentially affect management.

Correction to: Distal insertional anatomy of the triceps brachii muscle: MRI assessment in cadaveric specimens employing histologic correlation and Play-doh® models of the anatomic findings.

Figures 9, 10, 11, 12 and 15 corrected.

Distal insertional anatomy of the triceps brachii muscle: MRI assessment in cadaveric specimens employing histologic correlation and Play-doh® models of the anatomic findings.

OBJECTIVES: Assess the insertional anatomy of the distal aspect of the triceps brachii muscle using magnetic resonance imaging (MRI) in cadavers with histologic correlation and Play-doh® models of the anatomic findings. MATERIALS: Elbows were obtained from twelve cadaveric arm specimens by transverse sectioning through the proximal portion of the humerus and the midportion of the radius and ulna. MRI was performed in all elbows. Two of the elbow specimens were then dissected while ten were studied histologically. Subsequently, Play-doh® models of the anatomic findings of the distal attachment sites of the triceps brachii muscle were prepared. RESULTS: MRI showed a dual partitioned appearance of the distal attachment sites into the olecranon in all specimens. In the deeper tissue planes, the medial head muscle insertion was clearly identified while superficially, the terminal portion of the long and lateral heads appeared as a conjoined tendon. Histologic analysis, however, showed continuous tissue rather than separate structures attaching to the olecranon. CONCLUSION: Although MRI appeared to reveal separate and distinct attachments of the triceps brachii muscle into the olecranon, histologic analysis delineated complex but continuous tissue related to the attachments of the three heads of this muscle. The Play-doh® models were helpful for the comprehension of this complex anatomy and might serve as a valuable educational tool when applied to the analysis of other musculoskeletal regions.

Pes Anserinus: Anatomy and Pathology of Native and Harvested Tendons.

OBJECTIVE. The purpose of this article is to review the anatomy and pathology of the pes anserinus to increase the accuracy of imaging interpretation of findings affecting these medial knee structures. CONCLUSION. The pes anserinus, consisting of the conjoined tendons of the sartorius, gracilis, and semitendinosus muscles and their insertions at the medial aspect of the knee, is often neglected during imaging assessment. Common pathologic conditions affecting the pes anserinus include overuse, acute trauma, iatrogenic disorders, and tumors and tumorlike lesions.

Flexor carpi radialis brevis: a rare accessory muscle presenting as an intersection syndrome of the wrist.

The flexor carpi radialis brevis (FCRB) is a rare accessory muscle of the forearm and wrist. It is typically asymptomatic, but has been discovered either incidentally during cadaveric studies or at the time of surgery in patients with distal forearm injury. Rarely, the FCRB muscle is associated with pain. We report a patient with wrist pain related to intersection between the tendon of the FCRB muscle and the tendon of the flexor carpi radialis (FCR) muscle, with an associated longitudinal split tear of the FCR tendon, documented by magnetic resonance imaging (MRI). To our knowledge, this is only the second report in the English literature of this intersection syndrome.

The location of the peroneus longus tendon in the cuboid groove: sonographic study in various positions of the ankle-foot in asymptomatic volunteers.

OBJECTIVE: To evaluate the normal location of the peroneus longus tendon (PL) in the cuboid groove in various ankle-foot positions by ultrasonography in asymptomatic volunteers. MATERIALS AND METHODS: Ultrasonographic assessment of the PL in the cuboid groove was performed in 20 feet of ten healthy volunteers. Each PL was examined in five ankle-foot positions (i.e., neutral, dorsiflexion, plantar-flexion, supination, and pronation). The PL location was qualitatively categorized as "inside" when the PL was entirely within the cuboid groove, as "overlying" when some part of the PL was perched on the cuboid tuberosity, and as "outside" when the PL was entirely on the cuboid tuberosity. For quantitative evaluation of the PL location, the distance between the PL and the cuboid groove was measured. The width of the cuboid groove was measured in the neutral position. RESULTS: The PL location did not significantly change with changes in the ankle-foot position. Qualitatively, an "overlying" PL was the most common type, regardless of the ankle-foot position. "Inside" PLs were found in only 35, 20, 30, 25, and 35% of feet in neutral, dorsiflexion, plantar-flexion, supination, and pronation positions, respectively. The quantitative PL location was also not significantly different among all ankle-foot positions and it was significantly negatively correlated with the cuboid groove width. CONCLUSIONS: In healthy volunteers, 65% or more of the PLs were partially or completely located outside of the cuboid groove, regardless of the ankle-foot position. The PL location relative to the cuboid groove was related to the cuboid groove width.

Classification criteria for diffuse idiopathic skeletal hyperostosis: a lack of consensus.

Objectives: DISH is a condition characterized by flowing ossifications of the spine with or without ossifications of entheses elsewhere in the body. Studies on the prevalence and pathogenesis of DISH use a variety of partly overlapping combinations of classification criteria, making meaningful comparisons across the literature difficult. The aim of this study was to systematically summarize the available criteria to support the development of a more uniform set of diagnostic/classification criteria. Methods: A search was performed in Pubmed, Embase, Cochrane Library and Web of Science using the term DISH and its synonyms. Articles were included when two independent observers agreed that the articles proposed a new set of classification criteria for DISH. All retrieved articles were evaluated for methodological quality, and the presented criteria were extracted. Results: A total of 24 articles met the inclusion criteria. In all articles, spinal hyperostosis was required for the diagnosis of DISH. Peripheral, extraspinal manifestations were included as a (co-)requirement for the diagnosis DISH in five articles. Most discrepancies revolved around the threshold for the number of vertebral bodies affected and to defining different developmental phases of DISH. More than half of the retrieved articles described a dichotomous set of criteria and did not consider the progressive character of DISH. Conclusion: This systematic review summarizes the available different classification criteria for DISH, which highlights the lack of consensus on the diagnosis of (early) DISH. Consensus criteria, including consecutive phases of new bone formation that characterize DISH, can be developed based upon established diagnostic/classification criteria.

Utilization of CT scanning associated with complex spine surgery.

BACKGROUND: Due to the risk associated with exposure to ionizing radiation, there is an urgent need to identify areas of CT scanning overutilization. While increased use of diagnostic spinal imaging has been documented, no previous research has estimated the magnitude of follow-up imaging used to evaluate the postoperative spine. METHODS: This retrospective cohort study quantifies the association between spinal surgery and CT utilization. An insurance database (Humana, Inc.) with ≈ 19 million enrollees was employed, representing 8 consecutive years (2007-2014). Surgical and imaging procedures were captured by anatomic-specific CPT codes. Complex surgeries included all cervical, thoracic and lumbar instrumented spine fusions. Simple surgeries included discectomy and laminectomy. Imaging was restricted to CT and MRI. Postoperative imaging frequency extended to 5-years post-surgery. RESULTS: There were 140,660 complex spinal procedures and 39,943 discectomies and 49,889 laminectomies. MRI was the predominate preoperative imaging modality for all surgical procedures (median: 80%; range: 73-82%). Postoperatively, CT prevalence following complex procedures increased more than two-fold from 6 months (18%) to 5 years (≥40%), and patients having a postoperative CT averaged two scans. For simple procedures, the prevalence of postoperative CT scanning never exceeded 30%. CONCLUSIONS: CT scanning is used frequently for follow-up imaging evaluation following complex spine surgery. There is emerging evidence of an increased cancer risk due to ionizing radiation exposure with CT. In the setting of complex spine surgery, actions to mitigate this risk should be considered and include reducing nonessential scans, using the lowest possible radiation dose protocols, exerting greater selectivity in monitoring the developing fusion construct, and adopting non-ferromagnetic implant biomaterials that facilitate MRI postoperatively.

Acute and Stress-related Injuries of Bone and Cartilage: Pertinent Anatomy, Basic Biomechanics, and Imaging Perspective.

Bone or cartilage, or both, are frequently injured related to either a single episode of trauma or repetitive overuse. The resulting structural damage is varied, governed by the complex macroscopic and microscopic composition of these tissues. Furthermore, the biomechanical properties of both cartilage and bone are not uniform, influenced by the precise age and activity level of the person and the specific anatomic location within the skeleton. Of the various histologic components that are found in cartilage and bone, the collagen fibers and bundles are most influential in transmitting the forces that are applied to them, explaining in large part the location and direction of the resulting internal stresses that develop within these tissues. Therefore, thorough knowledge of the anatomy, physiology, and biomechanics of normal bone and cartilage serves as a prerequisite to a full understanding of both the manner in which these tissues adapt to physiologic stresses and the patterns of tissue failure that develop under abnormal conditions. Such knowledge forms the basis for more accurate assessment of the diverse imaging features that are encountered following acute traumatic and stress-related injuries to the skeleton. (©) RSNA, 2016.

Abnormal Bone Marrow Signal Intensity in the Phalanges of the Foot as a Manifestation of Raynaud Phenomenon: A Report of Six Patients.

OBJECTIVE: The objectives of our study were to describe the MRI findings of pedal phalangeal bone marrow edema in patients with Raynaud phenomenon (RP) and discuss the clinical implications of these MRI findings. CONCLUSION: There is a progressive distal-to-proximal pattern of pedal phalangeal bone marrow edema on MRI in patients with RP. This knowledge may allow early diagnosis and treatment of rheumatologic disorders that are potentially associated with RP.

Intramuscular migration of calcium hydroxyapatite crystal deposits involving the rotator cuff tendons of the shoulder: report of 11 patients.

OBJECTIVE: The intent of the study is to describe an unusual pattern of intramuscular migration of calcific deposits related to hydroxyapatite deposition disease (HADD) involving the rotator cuff, to illustrate the characteristic imaging features of this phenomenon, and to discuss the clinical significance of such migration. MATERIALS AND METHODS: A series of cases of intramuscular accumulation of calcium hydroxyapatite crystals collected over a 7-year period at multiple hospitals within the same academic institution were retrospectively reviewed. RESULTS: The patient group was composed of seven men and four women, ranging in age from 51 to 79 years, with a mean age of 63 years. All subjects presented with acute shoulder pain. The majority of subjects reported the spontaneous onset of the symptoms (64%), while others reported weight lifting (27%) and a fall on the arm (9%) as the mechanisms of injury. The right shoulder was affected in 73% of the subjects. The supraspinatus was the most commonly affected muscle (82%), followed by the infraspinatus muscle (36%). CONCLUSIONS: Knowledge of the imaging features of intramuscular migration of hydroxyapatite deposits is important in order to avoid the erroneous diagnosis of other causes of muscle edema and inflammation such as myotendinous injury, myositis, subacute denervation, and neoplasm.

Segond fracture: an MR evaluation of 146 patients with emphasis on the avulsed bone fragment and what attaches to it.

OBJECTIVE: To re-evaluate the Segond fragment emphasizing those structures that attach to the fragment in patients with reported acute/subacute anterior cruciate ligament (ACL) injuries, and to clarify the nomenclature used to describe these structures. MATERIALS AND METHODS: A search of databases of knee MR examinations over 4.5 years with reported ACL tears yielded 19,726 studies. Using strict exclusion criteria, a total of 146 MR studies with acute/subacute ACL tears were re-assessed with respect to the Segond fragment's size, shape, orientation, location, displacement, attaching soft tissue structures, and associated osseous and/or soft tissue injuries. RESULTS: Segond fractures were present in 1.25 % of reported acute/subacute ACL tears. The fragment measured 11.9 × 7.3 × 3.27 mm, being thin, ovoid, vertically oriented, situated anterolaterally along the proximal tibial epiphysis, posterior to Gerdy's tubercle and inferior to the lateral tibial plateau, and displaced up to 6 mm laterally. The attached structures were the meniscotibial component of the mid-third lateral capsular ligament (mt-MTLCL) in 58.9 %, both the mt-MTLCL and the posterior fibers of the ITB (pf-ITB) in 35.6 %, and the pf-ITB in 5.48 % of cases. In no case was there an additional attaching structure that did not meet criteria for the mt-MTLCL or the pf-ITB. CONCLUSION: The mt-MTLCL most commonly attaches to the Segond fragment, but the pf-ITB can also attach to this fragment. In no case was there an additional attaching structure that did not meet criteria for the mt-MTLCL or the pf-ITB.

Deep lateral notch sign and double notch sign in complete tears of the anterior cruciate ligament: MR imaging evaluation.

OBJECTIVE: To systematically compare the notches of the lateral femoral condyle (LFC) in patients with and without complete tears of the anterior cruciate ligament (ACL) in MR studies by (1) evaluating the dimensions of the lateral condylopatellar sulcus; (2) evaluating the presence and appearance of an extra or a double notch and its association with such tears. MATERIALS AND METHODS: This retrospective study was approved by our institutional review board, and informed written patient consent was waived. In 58 cases of complete ACL tears and 37 control cases with intact ACL, the number of notches on the LFC was determined, and the depth and anteroposterior (AP) length of each notch were measured in each third of the LFC. The chi-square test, t-test, and logistic regression model were used to analyze demographic data and image findings, as appropriate. RESULTS: Presence of more than one notch demonstrated a sensitivity of 17.2%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 43.5% for detecting a complete ACL tear. Lateral third depth measurement (p = 0.028) was a significant associated finding with a complete ACL tear. CONCLUSION: A deep notch in the lateral third of the LFC is a significant associated finding with a complete ACL tear when compared with an ACL-intact control group, and the presence of more than one notch is a specific but insensitive sign of such a tear.

Frequency of atlantoaxial calcium pyrophosphate dihydrate deposition at CT.

PURPOSE: To determine (a) the prevalence of atlantoaxial calcium pyrophosphate dihydrate (CPPD) crystal deposition in a population of patients undergoing computed tomography (CT) for acute trauma and (b) the association between atlantoaxial CPPD crystal deposition and retro-odontoid soft-tissue thickness. MATERIALS AND METHODS: This HIPAA-compliant study was approved by the institutional review board, and the requirement to obtain informed consent was waived. In 513 consecutive patients, CT scans of the cervical spine obtained for acute trauma were retrospectively reviewed for the presence of atlantoaxial CPPD crystal deposition, and the maximal thickness of the retro-odontoid soft tissues was measured. The relationships among imaging findings, age, and sex were assessed with the t test, the χ(2) test, Spearman correlation, and logistic and linear regression models as appropriate. RESULTS: The overall prevalence of atlantoaxial CPPD crystal deposition was 12.5% (64 of 513 patients), and prevalence increased with age (P < .0001, logistic regression coefficient). In patients aged 60 years and older, the prevalence of CPPD crystal deposition was 34% (58 of 170 patients). In patients aged 80 years and older, the prevalence of CPPD crystal deposition was 49% (37 of 75 patients). There was a positive correlation between age and retro-odontoid soft-tissue thickness (Spearman ρ = 0.48, P < .0001). The mean retro-odontoid soft-tissue thickness in patients with CPPD crystal deposition was greater than that in patients without CPPD crystal deposition (3.4 mm vs 2.2 mm, respectively; P < .0001, t test). CONCLUSION: CPPD crystal deposition in the cervical spine is seen with a higher prevalence than previously reported. CPPD crystal deposition shows a positive correlation with age and retro-odontoid soft-tissue thickening.

Stress fracture of the scapula in a professional baseball pitcher: case report and review of the literature.

We report a case of a 26-year-old, right-handed professional baseball pitcher who presented with gradually worsening right shoulder pain. Initial magnetic resonance imaging and computed tomography demonstrated a stress fracture involving the posterior aspect of the scapula at the junction between the scapular neck and body. After a period of rest, follow-up magnetic resonance imaging and computed tomography performed 3 1/2 weeks later demonstrated ongoing healing of the stress fracture.

Extensor retinaculum of the wrist: gross anatomical correlation with MR imaging after ultrasound-guided tenography with emphasis on anatomical features in wrist dorsiflexion responsible for tendon impingement.

OBJECTIVE: To demonstrate the anatomy of the extensor retinaculum (ER) of the wrist using gross anatomical correlation with magnetic resonance (MR) imaging before and after ultrasound-guided tenography in four different positions, emphasizing the morphological appearance of the ER that occurs with dorsiflexion of the wrist to define the nature of extensor tendon impingement in athletes who perform repetitive wrist dorsiflexion. MATERIALS AND METHODS: Institutional policies were followed regarding cadaver use. Ten upper extremities were harvested from fresh cadavers. MR imaging before and after ultrasound-guided tenography of the wrist was performed, followed by gross anatomical correlation. Two radiologists interpreted the MR images and sections by consensus for the anatomical landmarks of the ER, and morphological changes occurring during dorsiflexion of the wrist were analyzed and measured. RESULTS: The ER of the wrist appeared as a band of low signal intensity on T1- and PD-weighted images. Because of its orientation, axial images were best suited to depict the ER anatomy; specifically, localization of the bony landmarks and the septal attachments. On sagittal images, a consistent appearance of the ER was seen: appearing with fusiform morphology in the neutral position, and becoming shortened and thickened at the abutment point where the extensor tendons of the fourth compartment had a curved excursion during dorsiflexion. The width and thickness of the ER in neutral position averaged 13.56 mm and 1.67 mm respectively. In wrist dorsiflexion, the average width and thickness changed to 8.68 mm and 2.15 mm respectively. CONCLUSION: Magnetic resonance imaging is a useful technique to demonstrate the ER of the wrist, the septal attachments, and morphological changes that occur during dorsiflexion of the wrist, which potentially can lead to impingement of the extensor tendons.

High origin of the anterior band of the inferior glenohumeral ligament: MR arthrography with anatomic and histologic correlation in cadavers.

INTRODUCTION: The anterior band of the inferior glenohumeral ligament has been described to arise from the anteroinferior labrum, but we have observed that in some persons its origin is from the anterior or anterosuperior labrum, creating diagnostic difficulties. MATERIALS AND METHODS: Ten fresh unembalmed cadaveric shoulders underwent magnetic resonance arthrography (MRA) using a posterior approach with a 1.5 T GE magnet, with the following sequences: T1-weighted fast spin-echo in axial, coronal and sagittal planes, and T1 fat-suppressed spin-echo in the axial plane (TR/TE 600/20, section thickness 2.5 mm, 0.5 mm interslice space, number of signals acquired, two, field of view 12 × 12 cm, and matrix 512 × 256 pixels). Following imaging, the shoulders were frozen and later sectioned using a band saw into 3-mm sections corresponding to the axial imaging plane. Histological analysis was also performed to determine the origin of the anterior band. RESULTS: Four of the ten shoulders had an origin of the anterior band above or at the 3 o'clock position: one at the 1 o'clock position, two at the 2 o'clock position, and one at the 3 o'clock position. In another shoulder, the anterior band of the inferior glenohumeral ligament originated from the middle glenohumeral ligament, and in five other shoulders, the anterior band originated from the anteroinferior labrum as has been described in the literature. CONCLUSIONS: This finding is of clinical significance as a high origin of the anterior band of the inferior glenohumeral ligament leads to MR arthrographic finding that can simulate those of labral tears or detachments.

Valid MR imaging predictors of prior knee arthroscopy.

PURPOSE: To determine whether fibrosis of the medial patellar reticulum (MPR), lateral patellar reticulum (LPR), deep medial aspect of Hoffa's fat pad (MDH), or deep lateral aspect of Hoffa's fat pad (LDH) is a valid predictor of prior knee arthroscopy. MATERIALS AND METHODS: Institutional review board approval and waiver of informed consent were obtained for this HIPPA-compliant study. Initially, fibrosis of the MPR, LPR, MDH, or LDH in MR imaging studies of 50 patients with prior knee arthroscopy and 100 patients without was recorded. Subsequently, two additional radiologists, blinded to clinical data, retrospectively and independently recorded the presence of fibrosis of the MPR in 50 patients with prior knee arthroscopy and 50 without. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for detecting the presence of fibrosis in the MPR were calculated. κ statistics were used to analyze inter-observer agreement. RESULTS: Fibrosis of each of the regions examined during the first portion of the study showed a significant association with prior knee arthroscopy (p < 0.005 for each). A patient with fibrosis of the MPR, LDH, or LPR was 45.5, 9, or 3.7 times more likely, respectively, to have had a prior knee arthroscopy. Logistic regression analysis indicated that fibrosis of the MPR supplanted the diagnostic utility of identifying fibrosis of the LPR, LDH, or MDH, or combinations of these (p ≥ 0.09 for all combinations). In the second portion of the study, fibrosis of the MPR demonstrated a mean sensitivity of 82%, specificity of 72%, PPV of 75%, NPV of 81%, and accuracy of 77% for predicting prior knee arthroscopy. CONCLUSIONS: Analysis of MR images can be used to determine if a patient has had prior knee arthroscopy by identifying fibrosis of the MPR, LPR, MDH, or LDH. Fibrosis of the MPR was the strongest predictor of prior knee arthroscopy.

Ultrasound assessment of the lateral collateral ligamentous complex of the elbow: imaging aspects in cadavers and normal volunteers.

OBJECTIVE: The Lateral Collateral Ligamentous complex (LCL) is an important stabiliser of the elbow. It has a Y-shaped structure with three components. In this study, we sought to describe the ultrasound aspect of the individual components of this ligamentous complex and to evaluate the performance of ultrasound in both cadavers and in normal subjects. METHODS: Ten cadaveric elbow specimens underwent high-frequency ultrasound. Two specimens were sliced and two were dissected for anatomical correlation. Ten elbows of normal subjects were also evaluated by ultrasound. The findings were compared. RESULTS: The three components of the LCL could be visualised in all specimens and normal subjects with the exception of the proximal portion of one specimen. In 80% of the specimens and 100% of the healthy volunteers the proximal portion of the LCL could be separated from the extensor tendons. CONCLUSION: High-resolution ultrasound can assess all components of the LCL of the elbow and can distinguish them from surrounding structures.