| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||
ABSTRACT |
Tuesday, May 8, 1:30 PM–3:30 PM
Abstracts 130-141
Moderator(s): Amilcare Gentili and Hilary Umans
1:30 PM
130. CT Versus Radiography in the Diagnosis of Wrist Fractures
Welling R.*; Jacobson J. A.; Jamadar D.; Chong S.; Caoili E.; Jebson P. University of Michigan, Ann Arbor, MI
Address correspondence to R. Welling (rwelling{at}med.umich.edu)
Objective: To determine which wrist fractures are prospectively overlooked at radiography using CT as a gold standard, and to identify associated fracture patterns.
Materials and Methods: IRB approval was obtained. Through search of radiology records from the year 2005, 103 consecutive subjects were identified as having radiographic and CT examinations of the wrist. After excluding those with incomplete or nondiagnostic examinations and those with greater than 3-month time interval between imaging studies, the final study group consisted of 61 wrist examinations from 60 patients. CT examinations were blindly reviewed by two musculoskeletal radiologists and one emergency radiologist and each bone (scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, hamate, distal radius, distal ulna, proximal metacarpals) was categorized as normal or fracture, with agreement reached by consensus. Each prospective radiographic report was categorized as normal or fracture/equivocal for each osseous structure. Results were compared using Fisher's Chi Square Exact Test.
Results: CT showed 69 fractures in 45 of 60 patients. Of the 45 patients with fractures, 13 had two fractures, four had three fractures, and one had four fractures. There was fracture of the scaphoid in 16 wrists (with 13/16 or 81% diagnosed at prospective radiography), lunate in 3 (0/3 or 0% seen at radiography), triquetrum in 5 (1/5 or 20% seen at radiography), pisiform in 1 (1/1 or 100% seen at radiography), 3 trapezium (2/3 or 67% at radiography), 3 trapezoid (0/3 or 0% at radiography), 2 capitate (0/2 or 0% at radiography), 5 hamate (2/5 or 40% at radiography), 17 distal radius (16/17 or 94% at radiography), 6 ulna (6/6 or 100% at radiography), and 8 proximal metacarpal (6/8 or 75% at radiography). There was a significant relationship between radiography report and CT findings for scaphoid (p = 0.003), pisiform (p = 0.02), trapezium (p = 0.005), radius (p < 0.001), ulna (p < 0.05), and metacarpal fractures (p < 0.05). There was a significant relationship between scaphoid and radius fractures (p = 0.003), hamate and metacarpal fractures (p < 0.05), and radius and ulna fractures (p = 0.005).
Conclusion: In the proximal carpal row, lunate and triquetrum fractures were often occult, while in the distal carpal row, trapezoid, capitate, and hamate fractures were often occult. Most of these occult fractures (16/18 or 89%) were associated with another more obvious fracture visualized at radiography.
131. Occult Wrist Injuries: Prevalence and Distribution on MRI
Huang B.2*; Pierre-Jerome C.1; Tidland M.1; Monu J.2 1. Sahlgrenska-Molndal University Hospital, Molndal, Sweden; 2. University of Rochester Medical Center, Rochester, NY
Address correspondence to B. Huang (brady_huang{at}urmc.rochester.edu)
Objective: Persistence of wrist symptoms in a situation of negative radiographs after trauma is a frequent observation. This study analyzed the prevalence and extent of osseous and soft tissue abnormalities in patients with persistent wrist symptoms following trauma and negative radiographs.
Materials and Methods: MRI of the wrist was performed in 88 (48 men, 40 women) consecutive acute trauma patients with negative radiographs. The presence, distribution and prevalence of occult fractures and bone contusions in the wrist and distal forearm were assessed. Soft tissue lesions including muscle edema, ligament and cartilage tears and joint effusions were also evaluated.
Results: The patients were aged between 17 and 89 years. Sixty seven wrists had bone and soft tissue lesions. Fifty six wrists had multiple bone abnormalities. Bone contusions with occult fracture lines were detected in 32 (36%) wrists and 24 (27%) wrists with contusions did not show any fractures. The most occult fractures were seen in the distal radius (20 cases). Marrow edema were seen in the scaphoid (32 cases), the triquetrum (16 cases), and the hamate (16 cases). Muscle and soft tissue edema in the thenar and hypothenar areas were present in 42 (48%) wrists. TFCC tears were observed in 23 (26%) wrists. Effusions were present in all 56 wrists with multiple bone lesions, and more often situated in the ulnocarpal joint space-18 (32%) wrists.
Conclusion: Occult trabecular injuries are common in a setting of persistent symptoms and negative radiographs following wrist trauma. Soft tissue injuries are not unexpectedly common in this setting. MRI should be more readily used to improve diagnosis and to reduce suffering and morbidity.
132. 3.0-T MR Imaging of Wrist Ligament
Magee T.* NSI, Merritt Island, FL
Address correspondence to T. Magee (tmageerad{at}cfl.rr.com)
Objective: MR imaging of the wrist has been found to be sensitive and specific for detection of intrinsic ligament tears at 1.5 T or lower field strength as compared with arthroscopy. These studies were all limited by a small number of patients. 3.0-T MR imaging of the wrist for detection of intrinsic ligament tears has not been specifically assessed. This study assesses the sensitivity and specificity of MR imaging at 3.0 T for detection of intrinsic ligament tears of the wrist as compared with arthroscopy.
Materials and Methods: Two experienced musculoskeletal radiologists retrospectively reviewed MR images of the wrist in 300 consecutive patients. All patients had intermediate-weighted fat-saturated axial, coronal and sagittal images performed. Coronal T1-weighted images were also performed. MR images were read by consensus without knowledge of arthroscopy results. Scans were read as to whether there were full thickness scapholunate, lunatotriquetral or triangular fibrocartilage complex tears. No assessment was made as to possible partial thickness tears. Forty-three of the 300 patients went on to arthroscopy. After consensus review of MR images, arthroscopy results were compared with consensus MR interpretations.
Results: Of the 43 patients who went on to arthroscopy, 22 had TFCC tears, 18 had scapholunate tears and 11 had lunatotriquetral tears. Nineteen out of the 22 patients with TFCC tears at arthroscopy were seen on consensus MR reading. Sixteen of the 18 scapholunate ligament tears and nine of the eleven lunatotriquetral ligament tears seen at arthroscopy were seen on consensus MR reading. Some patients had more than one finding at arthroscopy. Four patients had both a TFCC tear and a lunatotriquetral ligament tear. There were no false-positive readings of intrinsic ligament ligaments tears on MR as compared with arthroscopy. In this study MR sensitivity for detection of TFCC tears was 86% and specificity was 100%. MR sensitivity for detection of scapholunate ligament tears was 87% and specificity was 100%. MR sensitivity for detection of lunatotriquetral ligament tears was 81% and specificity was 100%.
Conclusion: 3.0-T MR imaging is very sensitive and specific for detection of intrinsic ligament tears in the wrist.
133. MRI of the Extrinsic Ligaments of the Wrist with Surgical Correlation
Bergin D.2*; Qazi N.2; Sweet S.1 1. Philadelphia Hand Center, Philadelphia, PA; 2. Thomas Jefferson University Hospital, Philadelphia, PA
Address correspondence to D. Bergin (dianebergin{at}yahoo.com)
Objective: To assess extrinsic ligaments (EL) of the wrist on standard MRI in setting of acute trauma and chronic wrist pain. To correlate MRI findings with arthroscopy.
Materials and Methods: A database search was performed to identify patients who had MRI of the wrist over a 3 year period and arthroscopy within 3 months of the MRI. 83 patients were identified. MR studies were reviewed to evaluate radioscaphocapitate (RSC), radiolunotriquetral (RLT), radiolunate (RL), palmar radioulnar ligament (pRUL), dorsal radioulnar ligament (dRUL), palmar ulnotriquetral ligament (pUT), ulnolunate (UL), dorsal radiotriquetral (dRT), dorsal ulnotriquetral (dUT), radial collateral ligament (RCL) and ulnar collateral ligament (UCL).Intrinsic ligaments: palmar scaphotriquetral (pST) and dorsal scaphotriquetral (dST) were also assessed. By MR ligaments were deemed 0 = normal, 1 = torn, 2 = partial tear, 3 = thickened, 4 = wavy. Presence of marrow signal abnormality on T1- and T2-weighted sequences at ligamentous attachment sites was also noted. Presence of marrow edema or fractures elsewhere was recorded. Arthroscopy reports were reviewed to determine integrity of ELs at surgery.
Results: 83 MR studies of 37F and 46M (age range 13–73 yrs, mean 33 yrs) were reviewed. Indications for MRI were; acute trauma (40), chronic trauma and pain (14), chronic pain (no definite trauma) (29). Ligaments visualized on MR: RSC (77), RLT (73), RL (29), pUL (81), dRUL (83), pUL (63), UL (69), pST (77), dST (79), dRT (23), dUT (59), RCL (80), UCL (65). Ligaments visualized only in the axial plane: pST 9/68, dST 5/63, dRT 3/52. On MRI ligaments were normal, partially torn, thickened/edematous or wavy: RSC (62/1/13/1), RLT (59/1/13/0), RL (27/0/2/1), pRUL (67/0/2/1), dRUL (70/0/2/0), pUL (55/0/7/1), UL (56/0/11/2), pST (68/1/8/0), dST (63/0/14/1), dRT (52/0/8/0), dUT (46/0/11/2), RCL (56/0/23/1) and UCL (55/0/9/1). Abnormal marrow signal was noted specifically at EL attachment sites in 25% of acute trauma patients and 8% with chronic wrist pain. 53 patients had arthroscopy. In setting of acute trauma there was marrow edema at attachment sites palmar EL (30%) and dorsal EL (20%).There were no full thickness tears of EL at surgery. Partial tears and increased laxity of ELs was seen at arthroscopy of radial EL (1/0) and ulnar EL (4/3): corresponding abnormalities were identified on MR.
Conclusion: EL of the wrist maybe assessed on non arthrographic MR. Tears of ELs are extremely rare but abnormal marrow signal may frequently be seen at focal osseous ligamentous attachment sites in the setting of acute trauma.
134. Osteochondral Lesions of the Distal Tibial Plafond: Location and Morphological Characteristics on MRI
Elias I.2*; Zoga A. C.3; Morrison W. B.3; Beltran L.3; Schweitzer M. E.1; Raikin S. M.2 1. Hospital for Joint Diseases, Department of Radiology, New York, NY; 2. Thomas Jefferson University Hospital, Department of Orthopaedic Surgery, Rothman Institute, Philadelphia, PA; 3. Thomas Jefferson University Hospital, Department of Radiology, Philadelphia, PA
Address correspondence to I. Elias (ilan.elias{at}rothmaninstitute.com)
Objective: Osteochondral lesions of the distal tibial plafond (OLTPs) may be a source of ankle pain, however very little about this entity is reported in the literature. We sought to assess the frequency of OLTPs on MRI by location and evaluate morphologic characteristics of OLTPs occurring in different regions of the tibial plafond.
Materials and Methods: We assigned 9 equal-sized zones to the distal tibial plafond articular surface in a 3 x 3 grid configuration for an accurate depiction of lesion location. Zones were labeled "1" through "9" (zones 1 anteromedial; zone 3 = anterolateral; zone 9 = posterolateral). Two observers, a musculoskeletal radiologist and an orthopaedic surgeon then retrospectively reviewed MRI examinations with reported OLTPs, which were mapped onto the grid system and size/shape was recorded. MRIs showing ankle arthritis, osteonecrosis, fractures, neuroarthropathic changes, osteomyelitis, and fractures were excluded from the study. Once an OLTP was found, we also recorded any osteochondral lesion of the talar dome (OLTs) and mapped these onto a similar grid system on the talus. Comparison with clinical exam was recorded.
Results: We identified 31 subjects (average age 36 years old; range 11–68) with OLTPs. The average size of OLTPs was 6 x 5 x 4 mm with lesions in the anterior and posterior zones being deeper and cup-shaped in morphology and lesions at the equator of the plafond being more shallow and wafer-shaped. We found more frequent involvement in the posterior and in the medial zones than in the anterior and lateral zones. Five of the 31 subjects with OLTP had an OLT in a different zone, and one subject had a counterpart OLT in same zone (`kissing lesion'). Chart review revealed that all subjects had ankle pain.
Conclusion: Osteochondral lesions of the distal tibial plafond seem to be more frequent than reported in the literature and should be considered in the differential diagnosis of symptomatic ankles. The zone system makes it much easier to map the location and size of OLTs, which can assist in surgical planning and location of the lesions, particularly if the overlying cartilage is found to be intact.
135. Surgical Validation of Two Magnetic Resonance Imaging Classification Systems of Osteochondral Lesions of the Talus
Kijowski R.*; Foss E.; De Smet A. University of Wisconsin Hospital, Madison, WI
Address correspondence to R. Kijowski (r.kijowski{at}hosp.wisc.edu)
Objective: Two systems have been previously described for magnetic resonance imaging (MRI) classification of osteochondral lesions of the talus (OLT). This study was performed to compare these two classification systems with surgical findings to determine their usefulness for staging OLT.
Materials and Methods: The MRI examinations of 41 consecutive patients with surgically confirmed OLT were retrospectively reviewed by two musculoskeletal radiologists without knowledge of the surgical findings. The radiologists graded the OLT according to the Anderson classification system (grade I = subchondral bone marrow edema, grade II = partially detached fragment, grade IIA = subchondral cyst, grade III = detached but nondisplaced fragment, and grade IV = displaced fragment) and the De Smet classification system (unstable OLT characterized by a rim of high T2 signal, subchondral cysts, high T2 signal extending through cartilage into subchondral bone, or a displaced fragment). MRI findings were correlated with surgical findings of stability and instability.
Results: There were 3 stable and 38 unstable OLT at surgery. Of the 8 Anderson grade I OLT, 3 lesions were stable and 5 lesions were unstable at surgery. The presence of high T2 signal within the overlying cartilage could not be used to distinguish between stable and unstable Anderson grade 1 OLT. Anderson grade I OLT were not classifiable under the De Smet system. Of the 33 OLT classifiable under the De Smet system, all showed MRI findings of instability and all were unstable at surgery. These 33 unstable OLT were classified as grade II (1 lesion), grade IIA (14 lesions), grade III (17 lesions), and grade IV (1 lesion) under the Anderson system.
Conclusion: The De Smet classification system and grade II–IV lesions according to the Anderson classification system are sensitive and specific for assessing the stability of OLT. However, the De Smet system does not recognize Anderson grade 1 OLT. These Anderson grade 1 OLT, which are characterized by subchondral bone edema, may be stable or unstable.
136. Magnetic Resonance Imaging Findings in Patients with Tarsal Navicular Stress Injuries
Sidney S.*; Kijowski R.; Choi J.; Modica M.; De Smet A. University of Wisconsin School of Medicine and Public Health, Madison, WI
Address correspondence to S. Sidney (ssidney{at}uwhealth.org)
Objective: The magnetic resonance imaging (MRI) findings in patients with tarsal navicular stress injuries has been previously described only in small case reports. This study was performed to summarize the MRI findings in a larger number of patients with navicular stress injuries and to compare the usefulness of MRI with radiographs and computed tomography (CT) for the evaluation of these individuals.
Materials and Methods: The study group consisted of 17 athletes with clinically diagnosed tarsal navicular stress injuries who were evaluated with radiographs, CT, and MRI. The imaging studies of all patients were retrospectively reviewed in consensus by two fellowship-trained musculoskeletal radiologists and one musculoskeletal radiology fellow.
Results: All 17 patients with tarsal navicular stress injuries had normal radiographs. Twelve patients had incomplete longitudinal fracture lines through the dorsal cortex of the proximal portion of the middle third of the navicular on MRI and CT. One patient had an incomplete longitudinal fracture line through the dorsal cortex of the proximal portion of the lateral third of the navicular on MRI and CT. One patient had a complete longitudinal fracture line through the middle third of the navicular on MRI and CT. These 14 patients had associated bone marrow edema on MRI. The fracture lines in all 14 patients were equally conspicuous on MRI and CT. The short axis MRI and CT images through the midfoot were most helpful for identifying the fracture lines. The remaining 3 patients had focal confluent bone marrow edema within the dorsal proximal portion of the medial third of the navicular on MRI with no associated fracture line. These 3 patients had normal CT examinations and were given a final diagnosis of navicular stress injury.
Conclusion: MRI is as sensitive as CT for detecting tarsal navicular stress fractures and has the additional advantage of demonstrating bone marrow edema in patients with stress injury without a discrete fracture line.
137. MRI Appearance and Significance of Distal Peroneus Longus Tendon Tears
Mihalovich T.*; Helms C. A. Duke University, Durham, NC
Address correspondence to T. Mihalovich (mihal002{at}mc.duke.edu)
Objective: To describe the magnetic resonance (MR) imaging features and clinical presentation of distal peroneus longus tendon tears at the insertion on the first metatarsal.
Materials and Methods: Medical records and MR images in four patients with a tear of the distal insertion of the peroneus longus tendon were retrospectively reviewed. Standard ankle MRI was performed in each patient using 1.5-T magnets.
Results: Partial tears were present at the first metatarsal insertion in all four patients. Partial tears were characterized by high signal intensity within the tendon. No surrounding bony changes were identified. The Lisfranc ligament was normal in each patient.
Conclusion: Distal peroneus longus tendon tears are a relatively uncommon type of tear that have not been previously described in the radiology literature to our knowledge. However, these tears have important clinical implications and characteristic imaging features that can be visualized on routine ankle MRI studies. Given the location, these tears can mimic such clinical entities as Lisfranc ligament injury and metatarsal stress fractures.
138. Dynamic Ultrasound Evaluation of Peroneal Tendon Pseudosubluxation: Significance and Pattern Description
Elias I.1*; Zoga A. C.2; Raikin S. M.1; Nazarian L. N.3 1. Thomas Jefferson University Hospital, Department of Orthopaedic Surgery, Rothman Institute, Philadelphia, PA; 2. Thomas Jefferson University Hospital, Department of Radiology, Philadelphia, PA; 3. Thomas Jefferson University Hospital, Department of Radiology, Diagnostic Ultrasound Division, Philadelphia, PA
Address correspondence to I. Elias (ilan.elias{at}rothmaninstitute.com)
Objective: Dynamic ultrasound (US) has been shown to be a useful tool for diagnosing peroneal tendinopathies including subluxation and dislocation. Anecdotally, we have identified patients with clinical symptoms suspicious for peroneal tendon subluxation, who exhibit a reproducible peroneal tendon motion path during which the tendons interchange their position within the tendon sheath at the level of the lateral malleolus (pseudosubluxation). We sought to investigate the clinical significance and describe the dynamic US pattern of this unique imaging finding.
Materials and Methods: 14 patients (mean age: 35 years) with chronic lateral ankle pain underwent dynamic US examination with an experienced musculoskeletal sonographer using a 13-MHz transducer in axial, longitudinal and oblique planes at the lateral ankle. The peroneal tendons were imaged both at rest and during dynamic maneuvers. For dynamic scanning the ankle was dorsiflexed and everted both passively and actively from the neutral position while imaging the tendons at the level of the fibular groove. All patients subsequently underwent a surgical procedure including fibular groove deepening and superior peroneal retinaculum reconstruction. Using a similar imaging protocol, all patients then had postoperative ultrasound examination (mean follow-up: 26 months) at which time peroneal tendon morphology and motion was compared with the preoperative study, and change in symptomatology was recorded.
Results: On preoperative dynamic US the peroneus longus and peroneus brevis tendons showed abnormal motion relative to each other such that the two tendons temporarily reversed their normal anteroposterior relationship but remained retrofibular (pseudosubluxation) in all study patients. Five patients had associated longitudinal tendon tears. Intraoperative findings revealed a similar pseudosubluxation in all patients during open dynamic maneuvers, but no cases of true peroneal subluxation or dislocation. Postoperatively, followup ultrasound showed persistent pseudosubluxation in only 1/14 patients, all other preoperative peroneal tendon pathology had resolved.
Conclusion: Pseudosubluxation of peroneal tendons is an important imaging finding that can clinically mimic true subluxation or dislocation. Dynamic US is an excellent tool to evaluate peroneal tendon motion, and to distinguish between true subluxation and pseudosubluxation. In our study group, all patients reported significant improvement in chronic lateral ankle pain after stabilization of the peroneal tendons.
139. Sonographic Evaluation of Lateral Ankle Pain: Peroneal Tendon Pathology Associated with Symptomatic Os Peroneum and Sonographic Guided Therapeutic Options
Sofka C.*; Adler R.; Saboeiro G.; Pavlov H. Hospital for Special Surgery, New York, NY
Address correspondence to C. Sofka (sofkac{at}hss.edu)
Objective: Clinical implications of acute injuries of the os peroneum have been described, with the recommendation in some cases being the excision of the bone fragments. We describe the sonographic appearance of a painful os peroneum, document associated peroneal tendon pathology, and describe the applicability of sonography to direct and guide therapeutic and/or diagnostic injections.
Materials and Methods: All sonographic examinations in our ultrasound database from 1/1/01 to 2/28/06 with the words "os peroneum" were reviewed. Patients were cross referenced in our Radiology database to find relevant foot or ankle radiographs or MR examinations for correlation.
Results: There were 31 patients referred for sonographic evaluation of lateral foot and/or ankle pain who had an os peroneum identified during the sonographic evaluation. Twelve patients were referred specifically for targeted injection of the lateral ankle, including peroneal tendon sheath injections (n = 6), calcaneocuboid joint injections (n = 1) and injections around symptomatic os peroneum. (n = 5) All 31 patients had tendinosis of the peroneus longus, in varying degrees of severity. Clinical outcomes of these procedures will be discussed.
Conclusion: The causes of lateral ankle pain with a co-existent os peroneum are multifactorial and may not directly relate to the presence of an os peroneum. Ultrasound can be of value in separating out the specific etiology for pain, as well as provide a method for problem solving by the performance of targeted diagnostic or therapeutic injections in the lateral ankle.
140. Strange Bedfellows: Unusual Tarsal Coalitions
Desai K. R.*; Schweitzer M. E. New York University Department of Radiology, New York, NY
Address correspondence to K. Desai (kapil.desai{at}gmail.com)
Objective: Tarsal coalition is an infrequent but not rare cause of foot pain. Occurring in 1–2% of the population, nearly all are described at the calcaneonavicular and middle subtalar joints. We present a series of tarsal coalitions at atypical sites.
Materials and Methods: A computer database search was performed over a 7-year period to identify imaging studies of patients with coalitions occurring at the talonavicular, cuboidnavicular, calcaneocuboid, posterior subtalar, and various cuneiform articulations. Studies were reviewed for age of presentation, whether the coalition was complete, associated pedal anomalies, and the presence of an underlying skeletal dysplasia. These atypical coalitions were compared to the more usual coalitions as a window into relative prevalence.
Results: Of the 165 reported cases of tarsal coalition that we encountered, 92 (55.7%) were of the calcaneonavicular variety and 44 (26.6%) occurred at the middle subtalar joint. Seven cases each (4.2%) of cuboidnavicular and calcaneocuboid coalitions were reported (average age 35.7 and 18 years, respectively). Six cases of talonavicular coalition were described (average age 47.1 years). Three cases of posterior subtalar coalition and 1 case each of calcaneolateral cuneiform, cuboid-5th metatarsal, middle-lateral cuneiform, and navicular-medial cuneiform coalitions were also identified. The majority (4) of the cuboidnavicular coalitions were nonosseous while all 7 of the calcaneocuboid coalitions were osseous. Three of the talonavicular coalitions were nonosseous while 3 were osseous. Five patients were noted to have multiple tarsal coalitions and 1 had an underlying diagnosis of myositis ossificans progressiva.
Conclusion: Although surprisingly rarely described in the orthopedic or imaging literature, atypical tarsal coalitions appear to be more common than has been previously thought.
141. MRI of Lisfranc Injury: Accuracy and Spectrum of Disease
Dheer S.*; Zoga A.; Elias I.; Kavanagh E. C.; Morrison W. B.; Raikin S. M. 1. Thomas Jefferson University Hospital, Philadelphia, PA; 2. University of Pittsburgh Medical Center, Pittsburgh, PA
Address correspondence to S. Dheer (sachdheer{at}yahoo.com)
Objective: Lisfranc joint anatomy is well described, but description of traumatic injury is limited. This is the 1st report of soft tissue injury, including the plantar tarsometatarsal (TMT) (capsular) ligament. Recognition is important for appropriate treatment. We describe MRI findings in patients with Lisfranc joint injury, using surgery or exam under anesthesia as a standard.
Materials and Methods: 16 MRIs with suspected Lisfranc ligament (LFL) disruption were reviewed by 2 radiologists blinded to the surgical/clinical data. Fractures, LFL disruption on long/short axis, visibility of dorsal/plantar bands, fluid/bone marrow edema and integrity of plantar TMT ligaments were recorded. Correlation was made with surgical reports in all: 13 surgical, 3 EUA.
Results: All cases with suspected LFL injury had abnormal MRI's. At surgery, 10 complete and 3 partial tears and 3 intact LFLs were found. Of complete tears: on long axis, 7/10 were called complete tears, 2 called gr 2 and 1 gr 1 sprain. On short axis, 3/10 showed tear of dorsal and plantar bundles, 6 showed plantar and 1 dorsal bundle disruption. 8/10 had completely torn 2nd plantar TMT ligament. 8 had fluid along the 1st MT, 3 had fractures. For partial tears: on long axis, 2 were called gr 2 and 1 gr 1 sprain. On short axis, 2 were called gr 2 involving the plantar bundle of the LFL and 1 gr 1 sprain. Complete tear of the 2nd plantar TMT ligament was seen in 2/3 cases. No cases with partial LFL tears showed fluid along the 1st MT; all 3 had fractures. 3 intact ligaments: 0/3 were called torn on long/short axis images. 2 were called gr 1 sprain and 1 normal. 2/3 were called sprains of the plantar bundle, and the other normal. There was 1 fracture of the middle cuneiform. All 3 patients with clinical suspicion for LFL injury and an intact ligament at surgery showed MRI findings of a disrupted 2nd plantar TMT ligament.
Conclusion: MRI of the foot is sensitive and accurate in detecting various Lisfranc joint injuries, including sprain/disruption of the LFL, TMT fractures and associated capsular (plantar ligament) injury. We draw several new conclusions. Plantar capsular injury has not been reported with Lisfranc joint injury, but is present in the majority of cases (including cases with nl LFL). It may be a clinical confounder for LFL injury. Fluid along the first metatarsal is specific for complete LFL tear, seen in 8/10 true positives and 1 false negative MRI. Fractures are more common in patients with LFL sprain, suggesting that they may serve as a protective mechanism for the LFL.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
