Hilary Umans

The diagnostic role of gadolinium enhanced MRI in distinguishing between acute medullary bone infarct and osteomyelitis

The objective of the study was to evaluate the diagnostic utility of contrast enhanced magnetic resonance imaging (MRI) for distinguishing between acute medullary bone infarct and osteomyelitis. There were 11 patients (age 6-34 years) presented to our institution between December 1994 and February 1998 with a clinical differential diagnosis of acute bone infarct versus osteomyelitis and inconclusive radiographs were imaged using MRI. All but one received i.v. gadolinium. Nine of the patients had homozygous Sickle Cell disease (SCD) and two had Systemic Lupus Erythematosus (SLE), the latter requiring chronic methylprednisolone. Osteomyelitis was confirmed either by biopsy alone or by the combination of Gallium(67) scan in conjunction with positive blood cultures and clinical resolution following antibiotics. Infarcts without osteomyelitis were confirmed either by biopsy or resolution of symptoms without antibiotic therapy. All patients had at least six months clinical follow-up. The results found that seven of nine patients with SCD had acute infarct only. One patient with SCD had osteomyelitis only. Three patients (two SLE and one SCD) had both acute-on-chronic infarcts and superimposed osteomyelitis, one with an adjacent soft tissue abscess. Accurate distinction between infarct and osteomyelitis was impossible for one patient with SLE who did not receive contrast. All other cases were correctly diagnosed prospectively based on distinct patterns of MRI contrast enhancement. In all adult patients, acute infarcts demonstrated thin, linear rim enhancement on MRI while osteomyelitis revealed more geographic and irregular marrow enhancement. Two of four cases of osteomyelitis also demonstrated subtle cortical defects with abnormal signal traversing marrow and soft tissue. The single pediatric patient demonstrated elongated, serpiginous central medullary enhancement with periostitis. We concluded that the pattern of MR contrast enhancement may allow accurate distinction between acute infarct and osteomyelitis, or recognition of osteomyelitis superimposed on bone infarction.

Meniscal Root Tears: Diagnosis and Treatment

Meniscal tears within the body of the meniscus or at the meniscocapsular junction represent a well-understood and manageable condition encountered in clinical practice. In comparison, however, meniscal root tears (MRTs) often go unnoticed and represent a unique injury pattern with unique biomechanical consequences. Though first described decades ago, improvements in magnetic resonance imaging and arthroscopy have only recently enhanced our diagnostic and treatment capabilities with regard to MRTs. This review contains an anatomic description of the roots including their significance in meniscal function as well as the consequences of their loss. In addition, how to properly identify MRTs and when it is appropriate to surgically repair them are described. Finally, we review the surgical techniques available in the existing literature and present an illustrative case.

Slipped capital femoral epiphysis: a physeal lesion diagnosed by MRI, with radiographic and CT correlation.

Abstract Objective. To define and compare early lesions associated with slipped capital femoral epiphysis (SCFE) on magnetic resonance imaging (MRI), computed tomography (CT) and radiography. Design and patients. Thirteen patients with 15 symptomatic hips due to SCFE underwent radiography and MRI; CT was performed in 12 patients. SCFE was graded on radiographs, head/neck angles and qualitative changes were evaluated on CT, and morphologic/signal abnormalities were determined on MRI. Results. Physeal widening, apparent on T1-weighted MRI, was evident in every case of SCFE, including one presumed “pre-slip.” T2-weighted images demonstrated synovitis and marrow edema but obscured physeal abnormalities. CT head/neck angles ranged from 4–57° for symptomatic to 0–14° for asymptomatic hips. Physeal and metaphyseal changes were variably identified on both radiographs and CT in all cases of SCFE, but not in the pre-slip. Conclusion. MRI clearly delineates physeal changes of both pre-slip and SCFE, and demonstrates very early changes at a time when radiographs and CT may appear normal.

Longitudinal stress fractures of the tibia : diagnosis by magnetic resonance imaging

Abstract Objective. Previous works describe magnetic resonance (MR) imaging characteristics of stress fractures. Diagnosis of the atypical, longitudinal type of stress fracture has been reported using computed tomography (CT). This report focuses on MR imaging of longitudinal stress fractures of the tibia. Materials and methods. Six cases are presented in which a longitudinal linear abnormal marrow signal was detected in the middle and distal parts of the tibial shaft. Five patients were imaged using a 1.5 Tesla MR unit. Axial, sagittal and coronal T1 and T2-weighted or fat suppressed proton density fast spin echo images were obtained in all but one patient. One patient was imaged using a 0.5 Tesla MR unit with axial and coronal T1- and T2-weighted sequences. Initial conventional radiographs seen at clinical presentation were interpreted as normal in all cases. Two patients underwent radionuclide bone scan, and one patient was imaged with CT prior to MR imaging. Results. In each instance, MR imaging demonstrated linear marrow signal abnormalities orientated along the long axis of the tibial shaft. Endosteal and periosteal callus was identified on axial images. In all cases, MR imaging clearly demonstrated a fracture extending through one cortex with abnormal signal in both the marrow cavity as well as adjacent soft tissues indicating edema. Conclusion. MR imaging was shown to be excellent for demonstration of fracture lines, callus, and marrow and soft tissue abnormalities seen in association with longitudinal stress fractures.

Comparison of CT and MRI in patients with tibial plateau fracture: can CT findings predict ligament tear or meniscal injury?

Objective(1) To determine the accuracy of computed tomography (CT) in the evaluation of ligament tear and avulsion in patients with tibial plateau fracture. (2) To evaluate whether the presence or severity of fracture gap and articular depression can predict meniscal injury.Design and patientsA fellowship-trained musculoskeletal radiologist retrospectively reviewed knee CT and MRI examinations of 41 consecutive patients presenting to a level 1 trauma center with tibial plateau fractures. Fracture gap, articular depression, ligament tear and footprint avulsions were assessed on CT examinations. The MRI studies were examined for osseous and soft tissue injuries, including meniscal tear, meniscal displacement, ligament tear, and ligament avulsion.ResultsCT demonstrated torn ligaments with 80% sensitivity and 98% specificity. Only 2% of ligaments deemed intact on careful CT evaluation had partial or complete tears on MRI. Although the degree of fracture gap and articular depression was significantly greater in patients with meniscal injury compared with those without meniscal injury, ROC analysis demonstrated no clear threshold for gap or depression that yielded a combination of high sensitivity and specificity.ConclusionsIn the acute setting, CT offers high sensitivity and specificity for depicting osseous avulsions, as well as high negative predictive value for excluding ligament injury. However, MRI remains necessary for the preoperative detection of meniscal injury.

MRI features of confirmed "pre-slip" capital femoral epiphysis: a report of two cases

Abstract.We describe the morphologic and signal changes detected about the proximal femoral growth plate in two patients with hip pain preceding the progression to slipped capital femoral epiphysis using magnetic resonance imaging.

Sonographic Assessment of Volar Digital Nerve Injury in the Context of Penetrating Trauma

OBJECTIVE The purpose of this article was to report our experience using ultrasound to assess digital nerve integrity after penetrating hand trauma with sensory deficit. Ultrasound was performed in the long axis on 22 digital nerves in 11 patients using a 12-14-MHz linear array hockey stick transducer. CONCLUSION Of 22 volar digital nerves evaluated by sonography, six were transected. All imaging findings were confirmed surgically. High-frequency ultrasound permits accurate imaging of intact and transected volar digital nerves.

Anterior ankle impingement syndromes.

Ankle impingement syndromes are painful conditions that may complicate ankle trauma and are characterized by chronic, progressive pain, swelling, and limitation of movement. These disorders are subclassified according to anatomical location about the tibiotalar joint. This article reviews the various forms of anterior ankle impingement, detailing the unique clinical features, anatomical considerations, pathoetiology, and imaging findings for each.

Etiology, Clinical Assessment, and Surgical Repair of Plantar Plate Tears

The plantar plate has recently gained more attention as an important structure contributing to lesser metatarsophalangeal joint stability. This has prompted a significant growth of interest in the anatomy and biomechanics of the plantar plate and in the diagnosis and treatment of its injuries. Improved understanding of plantar plate function and predictable patterns of degeneration and failure has led to the development of a clinical staging and surgical grading system of plantar plate lesions. Relatively recent innovations allow the surgeon to access and repair plantar plate tears directly with reinsertion onto the base of the proximal phalanx. The addition of direct plantar plate repair represents a significant advance in the surgical restoration of alignment and functional stability of the lesser metatarsophalangeal joint.

All-inside, suture anchor repair for meniscal root tears

Dear Editor, We read the article ‘‘Arthroscopic all-inside repair for a tear of posterior root of the medial meniscus’’ by Choi et al. [1] with great interest. We would like to commend the authors on their work. However, it should be noted that this technique was published several years prior in Skeletal Radiology in the article, ‘‘Marginal fractures of the medial tibial plateau: possible association with medial meniscal root tear’’ [2]. In this article, we reported two cases of medial meniscal root avulsion in the setting of marginal fractures of the medial tibial plateau. These were repaired using a suture anchor technique using an accessory posteromedial working portal for access. Sutures were passed through the root using a Viper (Arthrex, Inc., Naples, FL, USA) suture passer more commonly used for rotator cuff repairs. The repairs were then tensioned using standard arthroscopic knot tying techniques from the anteromedial portal. One of the repairs was confirmed healed at second look arthroscopy for lysis of adhesions at 6 months, and the other on follow-up MRI at 10 months. The meniscal root is a critical structure, that when compromised is clearly associated with medial meniscal extrusion ([3 mm) [3]. This leads to biomechanical consequences that are similar to total menisectomy [4] and appears to be associated with the progression of osteoarthritis [5]. The combination of improved awareness of this injury, improved understanding of the critical importance of the meniscal root to the health of the knee, and the advancement of arthroscopic instrumentation has led to the development of several suture repair techniques. The majority of these have been described utilizing transosseous tunnels [6–8]. We agree with Choi et al., that the all-inside suture anchor repair technique should be strongly considered since it eliminates the issues of suture abrasion, tunnel drilling, and distal fixation inherent to trans-osseous tunnels. Since the time of our report, one of the authors (GD) has used this all-inside suture anchor technique for root repair on over ten occasions, using a variety of different suture anchor materials (Metal, Bio, PEEK). This technique has been used for the repair of both medial and lateral meniscal root avulsions. All of these root injuries were in the setting of multi-ligamentously injured knees that were treated in the early post-injury phase. All of the knees had significant pathologic laxity (3? opening to valgus and/or varus) that allowed us to use a standard posteromedial accessory portal for access. However, we are in agreement with Choi et al., in recommending the use of a high posteromedial portal to obtain the correct angle for insertion of the suture anchor when such pathologic laxity is not present. To date our experience has yielded good results without complication, and thus we encourage surgeons to consider the use of this technique for meniscal root repair. G. S. DiFelice (&) Division of Orthopaedic Surgery, Jacobi Medical Center, Albert Einstein College of Medicine, 1400 Pelham Parkway South, Bronx, NY 10461, USA e-mail: gdifelice@hotmail.com