Evaluation and Treatment of Entrapped Peripheral Nerve Catheters: A Case Report and Review.

Methods to remove retained peripheral nerve catheters range from non-invasive techniques to open surgical procedures. This study reviews two cases requiring surgical intervention for catheter remnant removal after catheter breakage and presents a systematic review describing the diagnosis and treatment of retained perineural catheters. While still very rare, our case report and systematic review demonstrate that retained nerve catheters can occur as the result of kinking or knotting, but also from catheter breakage. We recommend risk mitigation strategies for providers placing or caring for patients with regional nerve catheters.

The Heel Complex: Anatomy, Imaging, Pathologic Conditions, and Treatment.

The differential diagnosis for heel pain is broad but primarily involves abnormalities of the Achilles tendon, calcaneus, and plantar fascia. Achilles tendon disorders include tendinosis, tendinitis, and partial or complete tears. Tendinosis refers to tendon degeneration, while tendinitis is inflammation after acute overload. Untreated tendinosis can progress to partial or complete tears. Tendon disorders can be accompanied by paratenonitis or inflammation of the loose sheath enclosing the tendon. Initial management involves rehabilitation and image-guided procedures. Operative management is reserved for tendon tears and includes direct repair, tendon transfer, and graft reconstruction. The calcaneus is the most commonly fractured tarsal bone. The majority of fractures are intra-articular; extra-articular fractures, stress or insufficiency fractures, medial process avulsion, and neuropathic avulsion can also occur. Posterosuperior calcaneal exostosis or Haglund deformity, retrocalcaneal bursitis, and insertional Achilles tendinosis form the characteristic triad of Haglund syndrome. It is initially managed with orthotics and physiotherapy. Operative management aims to correct osseous or soft-tissue derangements. The plantar fascia is a strong fibrous tissue that invests the sole of the foot and contributes to midfoot stability. Inflammation or plantar fasciitis is the most common cause of heel pain and can be related to overuse or mechanical causes. Acute rupture is less common but can occur in preexisting plantar fasciitis. Conservative treatment includes footwear modification, calf stretches, and percutaneous procedures. The main operative treatment is plantar fasciotomy. Plantar fibromatosis is a benign fibroblastic proliferation within the fascia that can be locally aggressive and is prone to recurrence. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

The effect of spanning external fixation on entrapped structures in tibial pilon fractures.

PURPOSE: Pilon fractures are often complex injuries involving severe soft tissue injury. Studies have shown pilon fractures may entrap soft tissue structures between fracture fragments. Staged fixation of pilon fractures with spanning external fixation (SEF) is important for soft tissue rest and plays an important role in the management of these injuries. While SEF has been shown to promote soft tissue rest prior to definitive fixation, no studies have shown the effect SEF has on entrapped structures (ES). The purpose of this study was to evaluate how SEF effects ES in pilon fractures. METHODS: A retrospective review of 212 pilon fractures treated at our institution between 2010 and 2022 was performed. Patients with a CT scan pre-SEF and post-SEF met inclusion criteria. CTs were reviewed to characterize ES in pre- and post-SEF imaging. RESULTS: Of the 19 patients with ES identified on CT pre-SEF, seven (36.8%) had full release of ES post-SEF and 12 (63.2%) had no release of ES. The posterior tibial tendon was the most commonly ES and remained entrapped in 62.5% of cases. Only 25% of 43-C3 fractures had release of ES post-SEF, while 100% of 43-C1 and 43-C2 fractures demonstrated complete release of ES post-SEF. CONCLUSION: Entrapped structures in pilon fractures are likely to remain entrapped post-SEF, with only one-third of our cohort demonstrating release. In 43-C3 patterns, if ES are identified on CT pre-SEF, surgeons should consider addressing these either through mini open versus open approaches at the time of SEF as they are likely to remain entrapped post-SEF.

Anterior Tibial Artery Danger Zone During Anterolateral Plate Fixation of the Distal Tibia: A 3D Computed Tomography Angiogram Modeling Study.

OBJECTIVES: The objective of this study was to define the danger zone at which the anterior tibial artery (ATA) is at risk during anterolateral plating of the distal tibia using a novel 3D computed tomography angiography (CTA) modeling technique. METHODS: 116 patients (232 lower extremities) who underwent lower extremity CTAs between April 2020 and April 2022 were identified. Those with lower extremity trauma, evidence of a previously healed tibial fracture, or poor visualization of the ATA were excluded. The remaining 150 lower extremities (92 patients) were modeled with an anterolateral distal tibia plate using Sectra IDS7 software. The distance of the ATA from bony landmarks was measured perpendicular to the level at which the vessel intersected the plate. RESULTS: The ATA intersected the plate proximally at a mean distance of 10.5 cm (95% confidence intervals, 10.2-10.9) and at a mean distance of 4.6 cm (95% confidence intervals, 4.4-4.9) distally from the central tibial plafond. The ATA intersected with the plate as far distal as hole number 1 and as proximal as hole 14 of the plate. The greatest injury risk was associated with plate holes 3-8. In this region, the artery was at risk in 46-99 percent of specimens. CONCLUSIONS: The ATA is at risk when screws are placed percutaneously in an anterolateral distal tibia plate. The artery can be as close as 4.4 cm and as far as 10.9 cm proximal to the tibial plafond when crossing the plate, correlating to a risk of injury to the ATA at plate holes 1 through 14.

Shoulder and Elbow Injuries in Adult Overhead Throwers: Imaging Review.

Overhead throwing, particularly in baseball, subjects the shoulder and elbow to various unique injuries. Capsular contracture following repetitive external rotation shifts the humeral head posterosuperiorly, predisposing to glenohumeral internal rotation deficit (GIRD), Bennett, posterosuperior internal impingement (PSI), and superior labrum anterior-posterior (SLAP) lesions. GIRD represents loss of internal rotation at the expense of external rotation. Bennett lesion represents ossification of the posteroinferior glenohumeral ligament due to repetitive traction. PSI manifests with humeral head cysts and "kissing" tears of the posterosuperior cuff and labrum. Scapular dysfunction contributes to symptoms of PSI and predisposes to labral or rotator cuff disease. "Peel-back" or SLAP lesions occur when torsional forces detach the biceps-labral anchor from the glenoid. Finally, disorders of the anterior capsule, latissimus dorsi, teres major, and subscapularis are well recognized in overhead throwers. At the elbow, injuries typically involve the medial-sided structures. The ulnar collateral ligament (UCL) is the primary static restraint to valgus stress and can be thickened, attenuated, ossified, and/or partially or completely torn. Medial epicondylitis can occur with tendinosis, partial tear, or complete rupture of the flexor-pronator mass and can accompany UCL tears and ulnar neuropathy. Posteromedial impingement (PMI) and valgus extension overload syndrome are related entities that follow abundant valgus forces during late cocking or acceleration, and deceleration. These valgus stresses wedge the olecranon into the olecranon fossa, leading to PMI, osteophytes, and intra-articular bodies. Other osseous manifestations include olecranon stress fracture and cortical thickening of the humeral shaft. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Diagnosis of a Rare Flexor Tendon Entrapment Using 3D CT Imaging Techniques.

Flexor tendon entrapments as a result of fractures or dislocations in the upper extremity are rare. Diagnosis by clinical examination is not always possible, and imaging such as magnetic resonance imaging and ultrasound is often obtained. These modalities have the disadvantages of reduced sensitivity or increased cost and time, respectively. We present a unique case of a triquetral fracture and pisiform dislocation causing index finger flexor digitorum profundus (FDP-I) entrapment that was diagnosed preoperatively with computed tomography (CT) imaging with 3-dimensional (3D) volume rendering. A 30-year-old man presented in delayed fashion 4 weeks after a dune buggy accident. Among other injuries noted on examination, his index finger was held in flexion and unable to be passively extended. The CT source images showed dislocation and interposition of the FDP-I tendon within a fracture-dislocation of the triquetrum and pisiform. Postprocessed 3D volume renderings obtained from the CT source images confirmed this finding. The patient underwent operative intervention, where FDP-I entrapment between the triquetral fracture fragments and the dislocated pisiform was confirmed and released. Practitioners should be aware of this injury pattern and evolving advanced CT techniques which may be used to aid in soft-tissue diagnoses and obviate the need for additional advanced imaging.

Underlying Subclavian Artery Occlusion Initially Misdiagnosed in Weightlifter Using Anabolic Steroids: A Case Report and Review of Literature.

Subclavian artery occlusion (SAO) is a rare form of peripheral artery disease, sometimes associated with arterial thoracic outlet syndrome (ATOS). Subclavian arterial and venous occlusions are often misdiagnosed initially, and their clinical presentation can be confusing in bodybuilding athletes with increased vascularity in combination with anabolic steroid use. We present a 63-year-old male weightlifter with a history of hypertensive cardiomyopathy, renal transplant with left upper extremity arteriovenous fistula and subsequent takedown, cervical spinal stenosis, left rotator cuff surgery, and decades of testosterone injections who presented with years of left shoulder and neck pain. After having seen multiple providers and being diagnosed with various common disorders, CT angiography and conventional angiography were eventually performed and confirmed the presence of chronic SAO. The chronic occlusion was not deemed amenable to surgery or endovascular intervention and was treated medically with anticoagulation. Although anabolic steroid use is associated with arterial thrombosis, to our knowledge, this is the first reported case of SAO in a weightlifter. Initial misdiagnosis resulted in a long and costly workup. Although the patient's symptoms were consistent with occlusion (and his increased vascularity could potentially suggest chronic thrombosis of any kind), these key signs were masked given his weightlifting history, anabolic steroid use, and concurrent degenerative musculoskeletal conditions common to the weightlifting population. A thorough history, comprehensive physical examination, appropriate imaging studies, and a high index of suspicion for vascular occlusion in athletes who use steroids are critical for the timely diagnosis and treatment of SAO.

A wearable cardiac ultrasound imager.

Continuous imaging of cardiac functions is highly desirable for the assessment of long-term cardiovascular health, detection of acute cardiac dysfunction and clinical management of critically ill or surgical patients1-4. However, conventional non-invasive approaches to image the cardiac function cannot provide continuous measurements owing to device bulkiness5-11, and existing wearable cardiac devices can only capture signals on the skin12-16. Here we report a wearable ultrasonic device for continuous, real-time and direct cardiac function assessment. We introduce innovations in device design and material fabrication that improve the mechanical coupling between the device and human skin, allowing the left ventricle to be examined from different views during motion. We also develop a deep learning model that automatically extracts the left ventricular volume from the continuous image recording, yielding waveforms of key cardiac performance indices such as stroke volume, cardiac output and ejection fraction. This technology enables dynamic wearable monitoring of cardiac performance with substantially improved accuracy in various environments.

Successful real-world application of an osteoarthritis classification deep-learning model using 9210 knees-An orthopedic surgeon's view.

This study aimed to evaluate the performance of a deep-learning model to evaluate knee osteoarthritis using Kellgren-Lawrence grading in real-life knee radiographs. A deep convolutional neural network model was trained using 8964 knee radiographs from the osteoarthritis initiative (OAI), including 962 testing set images. Another 246 knee radiographs from the Far Eastern Memorial Hospital were used for external validation. The OAI testing set and external validation images were evaluated by experienced specialists, two orthopedic surgeons, and a musculoskeletal radiologist. The accuracy, interobserver agreement, F1 score, precision, recall, specificity, and ability to identify surgical candidates were used to compare the performances of the model and specialists. Attention maps illustrated the interpretability of the model classification. The model had a 78% accuracy and consistent interobserver agreement for the OAI (model-surgeon 1 К = 0.80, model-surgeon 2 К = 0.84, model-radiologist К = 0.86) and external validation (model-surgeon 1 К = 0.81, model-surgeon 2 К = 0.82, model-radiologist К = 0.83) images. A lower interobserver agreement was found in the images misclassified by the model (model-surgeon 1 К = 0.57, model-surgeon 2 К = 0.47, model-radiologist К = 0.65). The model performed better than specialists in identifying surgical candidates (Kellgren-Lawrence Stages 3 and 4) with an F1 score of 0.923. Our model not only had comparable results with specialists with respect to the ability to identify surgical candidates but also performed consistently with open database and real-life radiographs. We believe the controversy of the misclassified knee osteoarthritis images was based on a significantly lower interobserver agreement.

Intravascular papillary hemangioendothelioma disguised as a peripheral sheath tumor of median nerve at the wrist: a case report and literature review.

BACKGROUND: Intravascular papillary hemangioendothelioma (IVPH) is a benign lesion previously reported in the nasal cavity, neck, upper extremities, and breast. Diagnosis with cross-sectional imaging can prove difficult, with histopathological examination necessary for diagnosis. IVPH resulting in carpal tunnel symptoms is quite rare. CASE PRESENTATION: We report the case of a 37-year-old woman who presented with a radial, volar right wrist mass enlarging over the span of 5 years. She noted numbness and tingling in her wrist and thumb, exacerbated by minor accidental collisions and wrist hyperextension. There was no antecedent trauma. On examination, a mildly tender, mobile mass was evident at the volar aspect of the right wrist. Magnetic resonance imaging (MRI) with contrast demonstrated a lobulated, predominantly T2 hyperintense, heterogeneously enhancing mass thought to be a peripheral nerve sheath tumor. The patient elected for surgical excision of the mass, and the histopathological examination showed organizing thrombi with prominent papillary endothelial hyperplasia. At the 2-month follow-up, the patient had full range of motion of her fingers and wrist, with subjectively normal sensation in the distribution of the median nerve. CONCLUSION: Carpal tunnel syndrome, in exceedingly rare occasions, can result from an IVPH. MRI findings may be confused with more common entities. Histopathological confirmation remains necessary for conclusive diagnosis.

Interpretation of Cartilage Damage at Routine Clinical MRI: How to Match Arthroscopic Findings.

This review is intended to aid in the interpretation of damage to the articular cartilage at routine clinical MRI to improve clinical management. Relevant facets of the histologic and biochemical characteristics and clinical management of cartilage are discussed, as is MRI physics. Characterization of damage to the articular cartilage with MRI demands a detailed understanding of the normal and damaged appearance of the osteochondral unit in the context of different sequence parameters. Understanding the location of the subchondral bone plate is key to determining the depth of the cartilage lesion. Defining the bone plate at MRI is challenging because of the anisotropic fibrous organization of articular cartilage, which is susceptible to the "magic angle" phenomenon and chemical shift artifacts at the interface with the fat-containing medullary cavity. These artifacts may cause overestimation of the thickness of the subchondral bone plate and, therefore, overestimation of the depth of a cartilage lesion. In areas of normal cartilage morphology, isolated hyperintense and hypointense lesions often represent degeneration of cartilage at arthroscopy. Changes in the subchondral bone marrow at MRI also increase the likelihood that cartilage damage will be visualized at arthroscopy, even when a morphologic lesion cannot be resolved, and larger subchondral lesions are associated with higher grades at arthroscopy. The clinical significance of other secondary features of cartilage damage are also reviewed, including osteophytes, intra-articular bodies, and synovitis. Online supplemental material is available for this article. Work of the U.S. Government published under an exclusive license with the RSNA.

An Anatomic Study of the Lateral Dorsal Cutaneous Nerve Using 3-Tesla MRI: A Comparison to Cadaveric Data With Surgical Applications.

BACKGROUND: The lateral dorsal cutaneous nerve (LDCN) and the anastomotic branch of the sural nerve (AB) are cutaneous sensory nerves at risk of iatrogenic injury during lateral foot surgery. This study is the first to use a large cohort of high-resolution magnetic resonance images (MRIs) of the ankle to better describe the course of these nerves in vivo in order to aid surgeons intraoperatively. Our study intends to build on the "high and inside" approach to the proximal 5MT by accounting for variations in course of the LDCN and AB. METHODS: One hundred twenty-five 3-tesla (T) MRI studies of the ankle were analyzed. Three reviewers measured the distance from the LDCN and AB to landmarks including the most proximal aspect of the fifth metatarsal tuberosity (5MT) and the peroneus brevis tendon (PBT). RESULTS: Mean vertical distance from the LDCN to the 5MT was 0.8 ± 0.2 cm. Presence of an AB was visualized in 59 of 125 studies (47.2%) and was found 2.2 ± 0.5 cm dorsal to the 5MT. The AB was found to become superior to PBT at a horizontal distance 1.9 ± 0.5 cm proximal to the 5MT. The LDCN was found superior to the PBT at its insertion onto the 5MT in approximately 10% (n = 12) of our studies. During these instances, the LDCN was located an average of 0.3 cm dorsal to the PBT. CONCLUSION: Our proposed "safe zone" for the approach to the proximal 5MT remains superior to the LDCN and inferior to the AB and avoids crossing directly over either nerve in >95% of analyzed MRI studies. This incision begins 1.5 cm dorsal to the most proximal aspect of the 5MT and extends no more than 1 cm posteriorly. Careful dissection and identification of the LDCN and possible AB is necessary prior to further extension of incision. LEVEL OF EVIDENCE: Level IV, case series.

An Anatomic Study of the Sural Nerve Using 3-Tesla MRI: A Comparison to Cadaveric Data With Surgical Applications.

BACKGROUND: The sural nerve (SN) is a sensory cutaneous nerve that is at risk of iatrogenic injury during surgery at the lateral ankle. Prior anatomic studies of the SN are limited primarily to cadaveric studies with small sample sizes. Our study analyzed a large cohort of magnetic resonance images (MRIs) of the ankle to obtain a more generalizable, in vivo sample of distal SN course. METHODS: A total of 204 3-tesla MRI studies of the ankle were analyzed. Three reviewers measured the distance from the SN to various landmarks including the distal tip of the lateral malleolus (DTLM) and the lateral border of the Achilles tendon (LBA). RESULTS: Mean vertical distance from SN to DTLM was 2.2 cm (range, 0.9-3.6 cm). Mean horizontal distance from SN to DTLM and to LBA at the level of DTLM was 1.7 cm (range, 0.8-3.0 cm) and 1.9 cm (range, 1.0-2.9 cm), respectively. Mean horizontal distance from SN to LBA at the level of superior Achilles tendon insertion onto the calcaneus (SAI) was 2.6 cm (range, 1.4-3.7 cm), and mean horizontal distance from SN to LBA at 5 cm above SAI was 0.9 cm (range, 0.4-1.8 cm). CONCLUSION: The variation in SN course observed in our study allowed us to propose "safe zones" for several surgical approaches including the extensile lateral approach to the calcaneus (ELAC), the sinus tarsi approach (STA), the direct lateral approach to the lateral malleolus (DLA), and the posterolateral approach to the ankle (PLA), which we hope will minimize iatrogenic injury to the SN. LEVEL OF EVIDENCE: Level IV, case series.

Association Between Rotator Cuff Tears and Superior Migration of the Humeral Head: An MRI-Based Anatomic Study.

BACKGROUND: Superior humeral migration has been established as a component of rotator cuff disease, as it disrupts normal glenohumeral kinematics. Decreased acromiohumeral interval (AHI) as measured on radiographs has been used to indicate rotator cuff tendinopathy. Currently, the data are mixed regarding the specific rotator cuff pathology that contributes the most to humeral head migration. PURPOSE: To determine the relationship between severity of rotator cuff tears (RCTs) and AHI via a large sample of magnetic resonance imaging (MRI) shoulder examinations. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A search was performed for 3-T shoulder MRI performed in adults for any indication between January 2010 and June 2019 at a single institution. Three orthopaedic surgeons and 1 musculoskeletal radiologist measured AHI on 2 separate occasions for patients who met the inclusion criteria. Rotator cuff pathologies were recorded from imaging reports made by fellowship-trained musculoskeletal radiologists. RESULTS: A total of 257 patients (mean age, 52 years) met the inclusion criteria. Of these, 199 (77%) had at least 1 RCT, involving the supraspinatus in 174 (67.7%), infraspinatus in 119 (46.3%), subscapularis in 80 (31.1%), and teres minor in 3 (0.1%). Full-thickness tears of the supraspinatus, infraspinatus, or subscapularis tendon were associated with significantly decreased AHI (7.1, 5.3, and 6.8 mm, respectively) compared with other tear severities (P < .001). Having a larger number of RCTs was also associated with decreased AHI (ρ = -0.157; P = .012). Isolated infraspinatus tears had the lowest AHI (7.7 mm), which was significantly lower than isolated supraspinatus tears (8.9 mm; P = .047). CONCLUSION: Although various types of RCTs have been associated with superior humeral head migration, this study demonstrated a significant correlation between a complete RCT and superior humeral migration. Tears of the infraspinatus tendon seemed to have the greatest effect on maintaining the native position of the humeral head. Further studies are needed to determine whether early repair of these tears can slow the progression of rotator cuff disease.

Identifying the axillary nerve during shoulder surgery: an anatomic study using advanced imaging.

BACKGROUND: The axillary nerve (AXN) is one of the more commonly injured nerves during shoulder surgery. Prior anatomic studies of the AXN in adults were performed using cadaveric specimens with small sample sizes. Our research observes a larger cohort of magnetic resonance imaging (MRI) studies in order to gain a more representative sample of the course of the AXN and aid surgeons intraoperatively. METHODS: High-resolution 3T MRI studies performed at our institution from January 2010 to June 2019 were reviewed. Four blinded reviewers with musculoskeletal radiology or orthopedic surgery training measured the distance of the AXN to the surgical neck of the humerus (SNH), the lateral tip of the acromion (LTA), and the inferior glenoid rim (IGR). Intraclass correlation coefficient was calculated to assess reliability between reviewers. The nerve location was assessed relative to rotator cuff tear status. RESULTS: A total of 257 shoulder MRIs were included. Intraclass correlation coefficient was excellent at 0.80 for the SNH, 0.90 for the LTA, and 0.94 for the IGR. All intraobserver reliabilities were above 0.80. The mean distance from the AXN to SNH was 1.7 cm (range, 0.7-3.1 cm; interquartile range, 1.38-2.00) and that from the AXN to IGR was 1.6 cm (range, 0.6-2.6 cm; interquartile range, 1.33-1.88). The mean AXN to LTA distance was 7.1 cm, with a range of 5.2-9.0 cm across patient heights; there was a large effect size related to the LTA to AXN distance and patient height with a correlation of r = 0.603 (P < .001). Rotator cuff pathology appears to affect nerve location by increasing the distance between the AXN and SNH (P = .027). DISCUSSION/CONCLUSION: The AXN is vulnerable to injury during both open and arthroscopic shoulder procedures. This injury can be either a result of direct trauma to the nerve or secondary to traction placed on the nerve with reconstructive procedures that distalize the humerus. Our study demonstrates that the AXN can be found as little as 5.6 mm from the IGR and 6.9 mm from the SNH. In addition, we illustrate the relationship between patient height and the LTA to AXN distance and complete rotator cuff tears and the SNH to AXN distance. Our study is the first to demonstrate the nerve's proximity to important surgical landmarks of the shoulder using a large sample size of high-resolution images in living human shoulders.

Periosteal stripping in high ankle sprains: An association with osteonecrosis.

OBJECTIVE: We present a series of 20 cases of a sleeve-type injury of the distal tibia characterized by traumatic periosteal stripping caused by a high ankle sprain. We characterize the magnetic resonance imaging findings associated with this injury and highlight its association with distal tibial osteonecrosis. MATERIALS AND METHODS: We collected 20 cases of high ankle sprains with periosteal stripping of the distal tibia through teaching files and a search through our PACS database. We recorded the presence and pattern of syndesmotic ligamentous injury and the presence or absence of syndesmotic widening in patients with periosteal stripping. The presence or absence of associated fractures and osteonecrosis was noted and characterized by location. RESULTS: The most commonly torn ligament was the anterior inferior tibiofibular ligament. 25% (5/20) of the patients in our series developed osteonecrosis. Osteonecrosis developed as early as 3-4 weeks following the initial injury. Of the patients with osteonecrosis, 40% (2/5) had fractures of the posterior malleolus. All patients with osteonecrosis had widening of the syndesmosis. Two of the five patients with osteonecrosis were in the pediatric age group. CONCLUSION: In contrast to conventional syndesmotic and interosseous ligamentous tearing, high ankle injuries with tibial periosteal stripping may result in avulsion of the extra-osseous vasculature supplied by the periosteum, leading to osteonecrosis. This pattern of injury has not been emphasized in the literature. Our findings underscore the importance of the integrity of the periosteum for maintaining adequate vascularity of the distal tibia.

Greater trochanteric fractures with lntertrochanteric extension identified on MRI: What is the rate of displacement when treated nonoperatively?

INTRODUCTION: . Despite the ability of MRI to identify intertrochanteric (IT) fracture extension for greater trochanteric (GT) fractures, there is no consensus about which fractures require operative intervention. Previous studies have suggested GT fractures with >50% extension into the IT region might benefit from fixation. We sought to evaluate the rate at which GT fractures with IT extension displaced, requiring operative fixation. PATIENTS AND METHODS: . This is a Retrospective Chart Review performed at a Level 1 Trauma Center. Patients included all nonoperatively treated GT fractures (OTA/AO 31A1.1) with IT extension identified on MRI between 2010 and 2017 at our institution. Patients lost to follow up prior to radiographic evidence of healing or fracture displacement were excluded. Patient charts and imaging were reviewed for demographic data, treatment plan, percent extension into the IT region (as determined from coronal MRI images), and clinical and radiographic evidence of fracture healing. Percent extension into the IT region was measured using coronal T1-weighted MRI images. The primary outcome measures were fracture displacement requiring operation and nonunion. RESULTS: . Seventeen patients met initial inclusion criteria, with two subsequently excluded due to no radiographic follow-up. Of the 15 patients, zero had displacement of their IT fracture. None required operative intervention. All 15 patients healed their fractures. Fourteen of 15 (93%) had IT extension of 50% or less across the IT region. One patient had initial IT extension of 60%, this patient also healed without displacement. DISCUSSION: . Incomplete intertrochanteric femur fractures are a relatively newer diagnosis that have become more prevalent with the increased usage and availability of MRI. Currently, there is no consensus on the ideal treatment of these injuries. To our knowledge, this is the largest series of its kind to help guide treatment of these GT fractures with IT extension. CONCLUSIONS: . Fractures with less than 50% extension into the IT region have a low likelihood of future displacement and high union rates when treated nonoperatively. LEVEL OF EVIDENCE: . IV.

High-Resolution MRI of the First Metatarsophalangeal Joint: Gross Anatomy and Injury Characterization.

The first metatarsophalangeal joint (MTPJ) is vital to the biomechanics of the foot and supports a weight up to eight times heavier than the body during athletic activities. The first MTPJ comprises osseous and cartilaginous surfaces along with a complex of supporting structures, including the dorsal extensor tendons, collateral ligaments, and a plantar plate complex. In contradistinction to the lesser MTPJ plantar plates, a single dominant fibrocartilaginous capsular thickening does not exist at the first MTPJ. Instead, the plantar plate complex comprises a fibrocartilaginous pad that invests the hallux sesamoids and is inseparable from the plantar capsule, the intersesamoid ligament, paired metatarsosesamoid and sesamoid phalangeal ligaments (SPLs), and the musculotendinous structures. Acute injury at the first MTPJ is typically secondary to forced hyperextension-turf toe-and can involve multiple structures. During hyperextension, the resulting forces primarily load the distal SPLs, making these structures more susceptible to injury. SPL injuries are best seen in the sagittal plane at MRI. Radiography can also aid in diagnosis of full-thickness SPL tears, demonstrating reduced sesamoid excursion at lateral dorsiflexed (stress) views. Hallux valgus is another common condition, resulting in progressive disabling deformity at the first MTPJ. Without appropriate treatment, first MTPJ injuries may progress to degenerative hallux rigidus. The authors detail the anatomy of the first MTPJ in cadaveric forefeet by using high-resolution 3-T and 11.7-T MRI and anatomic-pathologic correlation. Injuries to the plantar plate complex, collateral ligaments, and extensor mechanism are discussed using clinical case examples. Online supplemental material is available for this article. ©RSNA, 2020.

Shoulder Tumor/Tumor-Like Lesions: What to Look for.

This article discusses the most common tumor and tumor-like lesions arising at the shoulder. Osseous tumors of the shoulder rank second in incidence to those at the knee joint and include benign osteochondromas and myeloma or primary malignant lesions, such as osteosarcoma or chondrosarcomas. Soft tissue tumors are overwhelmingly benign, with lipomas predominating, although malignant lesions, such as liposarcomas, can occur. Numerous tumor-like lesions may arise from the joints or bursae, due to either underlying arthropathy and synovitis (eg, rheumatoid arthritis and amyloid) or related to conditions, including tenosynovial giant cell tumor and synovial osteochondromatosis.