Graded stress radiography in acute injury to the lateral ligaments of the ankle

The diagnostic accuracy of graded stress radiography in 26 patients with acute injury to the lateral ankle ligaments has been compared with findings at arthrography and surgery. Measuring talar tilt angles and anterior talar displacement over a range of pressures applied to the distal tibia using a commercially available stress device allows diagnostic distinction between isolated anterior talofibular ligament injury and a combined lesion that involves the calcaneofibular ligament. The results compare well with arthrographic and surgical findings.     

膝关节韧带损伤的MRI诊断

目的:探讨膝关节韧带损伤的MRI表现及诊断价值。方法:36例临床怀疑膝关节损伤的患者于关节镜及手术前行MRI检查,以关节镜结果作为金标准,前瞻性分析膝关节韧带损伤的MRI表现及诊断价值。结果:关节镜证实前交叉韧带损伤21例,其中完全撕裂15例,部分撕裂6例,后交叉韧带损伤12例,正常患者15例。MRI诊断前交叉韧带损伤的敏感度为95.2%,特异度为80%,准确度为88.9%;诊断后交叉韧带损伤的敏感度为100%,特异度为95.8%,准确度为97.2%。结论:MR1是诊断膝关节韧带损伤的理想检查方法,具有较高的临床应用价值。     

Acute and chronic tears of the anterior cruciate ligament: differential features at MR imaging

To evaluate the differential features of acute and chronic tears of the anterior cruciate ligament at magnetic resonance (MR) imaging, the authors performed a retrospective evaluation of findings in 81 MR examinations correlated with results at arthroscopy. Intact anterior cruciate ligaments (ACLs) were present in 29 patients; acute complete ACL tears, in 22; and chronic complete ACL tears, in 30. Acute tears were accurately distinguished from intact ligaments and were characterized by the presence of edema. Chronic tears had a more variable appearance: Nine (30%) were depicted at MR as intact bands with low signal intensity that bridged the expected origin and insertion of the ACL. This appearance is likely due to the presence of bridging fibrous scars within the intercondylar notch. Five of these nine cases were correctly characterized as chronically torn because of the presence of focal angulation. In four of these nine cases the scarred fragments produced a relatively straight band that mimicked an intact ligament. Although chronic and acute ACL tears usually have distinct findings at MR, a chronic tear will occasionally be difficult to distinguish from an intact ligament.     

Tears of cruciate ligaments and menisci: evaluation with cine MR imaging

A cine magnetic resonance (MR) imaging technique, involving the acquisition of kinematic sagittal images during knee movement, was used to evaluate 52 symptomatic knee joints. Results were compared with those obtained by means of static three-dimensional (3D) MR imaging. Twenty-seven of the 28 anterior cruciate ligament (ACL) tears and 22 of 24 normal ligaments were correctly identified at cine MR imaging for a sensitivity of 96% and a specificity of 92%. Static 3D MR imaging yielded a sensitivity of 71% and a specificity of 88%. All four posterior cruciate ligament tears were identified at cine and 3D MR imaging. For meniscal tears, cine MR imaging yielded a sensitivity of 48% and a specificity of 96%; the sensitivity and specificity for 3D MR imaging were 71% and 96%, respectively. Cine MR imaging proved to be more useful than static MR imaging in assessing the tightness of cruciate ligaments, especially of those that were partially torn, and in assessing the movement of meniscal-free fragments. The increased information obtained with cine MR imaging may warrant continued investigation and clinical application.     

膝关节半月板损伤的MRI与关节镜对照研究

目的评价MRI在膝关节半月板撕裂诊断和评级中的价值。方法参照Mesgarzadeh标准对76位患者78个撕裂半月板的MR影像作回顾性分析,3位MRI主治医师在不知道关节镜检查结果的情况下独自阅片,按Mesgarzadeh的分级标准确定半月板撕裂的类型并记录评定结果,包括联合的前交叉韧带撕裂。结果MRI诊断半月板撕裂的敏感性和特异性分别为92%和87%,Ⅵ型是半月板撕裂中最常见的类型,尤其在发生移位的半月板撕裂中最常见。结论MRI是半月板撕裂伤和交叉韧带损伤的可靠诊断工具。     

Magnetic resonance imaging of anterior cruciate ligament tears: reevaluation of quantitative parameters and imaging findings including a simplified method for measuring the anterior cruciate ligament angle

We evaluated the diagnostic utility of magnetic resonance imaging (MRI) for predicting anterior cruciate ligament (ACL) tears using both quantitative parameters and nonquantitative imaging findings. MRI examinations were retrospectively evaluated in a group of patients with arthroscopically confirmed complete ACL tear and in a control group with arthroscopically confirmed intact ACL. We evaluated multiple MRI features to compare their sensitivity and specificity for detecting ACL tears. Particular emphasis is put on the evaluation of three different quantitative parameters, including a simplified method for measuring the ACL angle. With a threshold value of 45° the ACL angle reached a sensitivity and specificity of 100% for detecting ACL tears. With a threshold value of 0° the Blumensaat angle had a sensitivity of 90% and a specificity of 98%. Finally, a threshold value of 115° gave the posterior cruciate ligament angle a sensitivity of 70% and a specificity of 82%. Discontinuity was found to be the most useful of the ACL abnormalities. Of the secondary findings anterior tibial displacement was the best predictor of ligamentous injury. However, ACL abnormalities and secondary findings, alone or combined, failed to surpass the diagnostic value of the ACL angle for predicting ACL tears. Quantitative parameters are thus good predictors of ACL tears and may increase the overall sensitivity and specificity of MRI. The ACL angle may be confidently measured in a single MRI section and can be considered to be the most reliable quantitative parameter for detecting ACL tears.     

Anterior cruciate ligament tears: MR imaging-based diagnosis in a pediatric population

PURPOSE: To evaluate the diagnostic accuracy of primary and secondary magnetic resonance (MR) imaging findings of anterior cruciate ligament (ACL) tears in young patients with immature skeletal systems. MATERIALS AND METHODS: MR images obtained in 43 patients aged 5-16 years who underwent arthroscopy were retrospectively reviewed. Two reviewers evaluated primary findings (abnormal signal intensity, abnormal course as defined by Blumensaat angle, and discontinuity), secondary findings (bone bruise in lateral compartment, anterior tibial displacement, uncovering of posterior horn of lateral meniscus, posterior cruciate ligament line, and posterior cruciate angle), and meniscal and other ligamentous injuries. RESULTS: There were 19 ACL tears and 24 intact ACLs. Overall sensitivity and specificity of MR imaging in detecting ACL tears were 95% and 88%, respectively. Sensitivities of the primary findings were 94% for abnormal Blumensaat angle; 79%, abnormal signal intensity; and 21% discontinuity. The specificity of all primary findings was 88% or greater. The sensitivity and specificity of the secondary findings, respectively, were 68% and 88% for bone bruise; 63% and 92%, anterior tibial displacement; 42% and 96%, uncovered posterior horn of lateral meniscus; 68% and 92%, positive posterior cruciate line; and 74% and 71%, abnormal posterior cruciate angle. Fifteen (79%) patients had meniscal tears, and five (26%) had collateral ligament injuries. CONCLUSION: Primary and secondary findings of ACL tears in young patients have high specificity and are useful for diagnosis.     

Surgical treatment of acl-pcl-medial side-lateral-side injuries of the knee

The multiple-ligament-injured knee is a complex problem in orthopaedic surgery. Most dislocated knees involve tears of the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and at least one collateral ligament complex. Careful assessment of the extremity vascular status is essential because of the possibility of arterial and/or venous compromise. These complex injuries require a systematic approach to evaluation and treatment. Physical examination and imaging studies enable the surgeon to make a correct diagnosis and to formulate a treatment plan. Arthroscopically assisted combined ACL/PCL reconstruction is a reproducible procedure. Knee stability is improved postoperatively when evaluated by using knee-ligament rating scales, arthrometer testing, and stress radiographic analysis. Acute medial collateral ligament tears when combined with ACL/PCL tears may, in certain cases, be treated with bracing. Posterolateral corner injuries combined with ACL/PCL tears are best treated with primary repair, as indicated, combined with reconstruction by using a post of strong autograft (split biceps tendon, biceps tendon, semitendinosus) or allograft (Achilles tendon, bone—patellar tendon—bone) tissue. Surgical timing depends on the ligaments injured, the vascular status of the extremity, reduction stability, and the overall health of the patient. We prefer the use of allograft tissue for reconstruction in these cases because of the strength of these large grafts and the absence of donor-site morbidity.     

Synovialisation of the torn anterior cruciate ligament of the knee: comparison between magnetic resonance and arthroscopy

The aim of this study was to assess the accuracy of MR in the diagnosis of synovialisation of the anterior cruciate ligament (ACL) compared with arthroscopy. One hundred and forty-nine patients were examined with MR imaging and arthroscopy of the knee. The MR sign used to consider a synovialised ACL consisted of hypointense fibrillar tracts, disrupted and wavily, in its expected course. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), comparison of proportions (McNemar test) and Kappa values for agreement between MR imaging and arthroscopy were calculated. Of the 133 (89.3 %) ligaments without synovialisation at arthroscopy, 130 accorded with the MR results. Of the 16 (10.7 %) synovialised ligaments, 13 accorded with the MR results. Three false-positive and three false-negative MR diagnoses were identified. The agreement between both techniques was excellent (Kappa = 0.79; p = 0.000), without differences (McNemar test; p = 1). Sensitivity was 0.81, specificity 0.98, PPV 0.98 and NPV 0.81. Magnetic resonance imaging is highly reliability for synovialisation diagnosis. The imaging sign used to diagnose synovialised ACL (hypointense comma-like tracts in its expected course) is reliable. As this reparative process can simulate an intact ligament, knowledge of this sign is important in diagnosing synovialisation of ACL tears so as not to confuse it with normal ACL. Received: 17 June 1998; Accepted: 6 August 1998     

MR imaging of the knee in the sagittal projection: comparison of three-dimensional gradient-echo and spin-echo sequences

Fifty patients with suspected internal derangement of the knee had arthroscopic examinations after MR imaging with both a standard T1-weighted spin-echo (SE) sequence and a three-dimensional (3-D) gradient-echo sequence. This series permitted correlative evaluation of 100 menisci and 50 anterior cruciate ligaments. Meniscal tears were diagnosed when intrameniscal signal communicated with the meniscal surface. Criteria for diagnosing anterior cruciate ligament disruption included absence or discontinuity of the ligament, ligamentous laxity, and hyperflexion of the posterior cruciate ligament. Arthroscopic surgery confirmed the presence of 39 meniscal tears and 11 anterior cruciate ligament tears in this population. The sensitivity and specificity of the SE sequence for the diagnosis of meniscal tears were 77% and 98%, respectively. The 3-D gradient-echo sequence had a sensitivity of 87% and a specificity of 88%. For disruption of the ligament, the SE technique had a sensitivity of 82% and a specificity of 95% and the 3-D technique had a sensitivity of 64% and a specificity of 100%. Although these differences in sensitivity and specificity are not statistically significant at the p less than .05 level, probably because of the small sample size, the results show the relative strengths and weaknesses of the two imaging sequences. These data suggest that because of the complementary results of the two MR techniques, both the SE and the 3-D gradient-echo sequences have a role in the diagnosis of knee injuries.     

Acute spinal ligament disruption: MR imaging with anatomic correlation

Disruption of spinal ligaments can lead to instability that jeopardizes the spinal cord and nerve roots. Magnetic resonance (MR) imaging can directly image spinal ligaments; however, the sensitivity with which this modality demonstrates ligament injury has, to the authors' knowledge, not been reported. On a biomechanical testing machine, 28 cadaveric spines were subjected to controlled injury that resulted in ligament tears. The spines were then imaged with plain radiography, computed tomography, and MR imaging (1.5 T). The images were analyzed for evidence of ligament injury before dissection of the specimen. Forty-one of 52 (79%) ligament tears of various types were correctly identified at MR imaging. Disruptions of the anterior and posterior longitudinal ligaments were most conspicuous and were detected in all seven cases in which they were present (no false-positive or false-negative results); disruptions of the ligamentum flavum, capsular ligaments, and interspinous ligaments could also be identified but less reliably (three false-positive and 11 false-negative results). That MR imaging can reliably and directly allow assessment of spinal ligament disruption in this in vitro model suggests its potential utility for this assessment in patients.     

Strain measurement in lateral ankle ligaments

We measured strain in the lateral ligaments of 10 human cadaver ankles while moving the ankle joint and applying stress in a variety of ways. We studied the anterior talofibular, calcaneofibular, posterior talofibular, anterior tibiofibular, and posterior tibiofibular ligaments. Strain measurements in the ligaments were recorded continuously while the ankle was moved from dorsiflexion into plantar flexion. We then repeated measurements while applying inversion, eversion, internal rotation, and external rotation forces. Strain in the anterior talofibular ligament increased when the ankle was moved into greater degrees of plantar flexion, internal rotation, and inversion. Strain in the calcaneofibular ligament increased as the talus was dorsiflexed and inverted. These findings support the concept that the anterior talofibular and calcaneofibular ligaments function together at all positions of ankle flexion to provide lateral ankle stability. We measured maximum strain in the posterior talofibular ligament when the ankle was dorsiflexed and externally rotated. The strain in the anterior and posterior tibiofibular ligaments increased when the ankle was dorsiflexed. External rotation increased strain in the anterior tibiofibular ligament and decreased strain in the posterior tibiofibular ligament. Based upon strain measurements in the lateral ankle ligaments in various ankle joint positions, we believe the anterior talofibular ligament is most likely to tear if the ankle is inverted in plantar flexion and internally rotated. Theoretically, the calcaneofibular ligament tears primarily in inversion if the ankle is dorsiflexed; the anterior tibiofibular ligament tears in dorsiflexion, especially if combined with external rotation; and the posterior tibiofibular ligament tears with extreme dorsiflexion.     

膝关节交叉韧带低场强MRI表现及其损伤诊断

目的 :研究膝关节正常交叉韧带MRI特点和交叉韧带损伤的的MRI表现。方法 :对 2 0 0例正常膝关节交叉韧带的MRI进行回顾性分析 ,对 2 5例临床可疑交叉韧带损伤患者的MRI资料和关节镜检查行对比研究。结果 :正常膝关节矢状位MRI上显示交叉韧带最佳 ,冠状位和横断位作为补充 ,交叉韧带损伤的MRI表现为韧带连续性中断、局灶性或弥漫性肿胀、信号强度增高及断端移位 ;以关节镜检查结果为标准 ,MRI诊断交叉韧带损伤的敏感度为 91.3 % ,特异度为 91.6% ,符合率为 91.4%。结论 :MRI多方位扫描是一种准确诊断交叉韧带损伤的方法 ,矢状位显示交叉韧带最佳。     

Diagnostic efficacy in knee MRI comparing conventional technique and multiplanar reconstruction with one-millimeter FSE PDW images

Background: Magnetic resonance (MR) imaging has proved to be an excellent tool in diagnosing injuries of the cruciate ligaments and menisci. However, multiple planes and sometimes optimal oblique or double-oblique scan planes are needed due to the variability in the positioning of important structures, which means there is a lower throughput and longer scanning time.

Purpose: To compare the performance of a 1-mm-thickness fast spin-echo (FSE) proton-density-weighted (PDW) MR imaging technique with multiplanar reconstruction (MPR) in diagnosing tears of the menisci and cruciate ligaments with that of conventional MR imaging.

Material and Methods: Twenty-five consecutive patients underwent preoperative conventional and 1-mm-thickness FSE PDW MR imaging with subsequent knee arthroscopic surgery. Two musculoskeletal radiologists evaluated the status of the cruciate ligaments and menisci using two sets of MR images (method A: conventional images including seven sequences, taking 26 min; method B: 1-mm-thickness FSE PDW images with MPR, taking 7 min 20 s). The diagnostic efficacies of both methods for tears of the cruciate ligament and menisci were calculated and compared.

Results: Arthroscopic surgery revealed 10 anterior cruciate ligament (ACL) tears, one posterior cruciate ligament (PCL) tear, and 26 meniscal tears. The diagnostic values of both methods were 100% for a cruciate ligament tear. The diagnostic values (sensitivity, specificity, accuracy, positive predictive value, and negative predictive value) for meniscal tears were 90%, 100%, 96%, 100%, and 94% for method A, and 95%, 100%, 98%, 100%, and 97% for method B, respectively. There were no significant differences in the diagnostic values between methods A and B.

Conclusion: 1-mm-slice-thickness FSE PDW imaging with MPR showed comparable performance in diagnosing tears of the cruciate ligaments and menisci to conventional sequences but the scan time was much shorter. Therefore, this technique (method B) might improve the throughput of a 3T MR imaging system.     

Clinical association of acute lateral ankle sprain with syndesmotic involvement: a stress radiography and magnetic resonance imaging study

BACKGROUND: Information concerning the clinical association between syndesmosis injury and grade of lateral ankle ligament damage would aid in the diagnosis and treatment of ankle sprains. HYPOTHESIS: Evaluation of lateral ligament injury in terms of percentage tear of both the anterior talofibular and calcaneofibular ligaments can provide information on the extent of syndesmotic involvement. STUDY DESIGN: Prospective cohort study. METHODS: Twenty-five patients volunteered to have magnetic resonance imaging examinations performed and 21 volunteered to undergo graded stress radiographs. Talar tilt angles were measured from radiographs taken with 0, 6, 9, 12, and 15 daN of force applied medially just above the ankle joint, and the percentage of ligament tear and grade of injury were determined. Scans were obtained with the foot in neutral and plantar flexion to image the anterior talofibular and calcaneofibular ligaments. RESULTS: Grades of lateral ligament injury determined by magnetic resonance imaging and graded stress radiography were the same. The extent of syndesmotic injury could be assessed for all patients. CONCLUSIONS: Intact tibiofibular ligaments were found equally frequently among patients with normal or any grade of lateral ligament damage, but the more severe injuries to the syndesmotic ligaments were associated with normal or minimally traumatized lateral ligaments. The inverse correlation can be explained on the basis of the difference between the mechanisms that precipitate these injuries.     

Anterior cruciate ligament tears and associated meniscal lesions: assessment at dual-detector spiral CT arthrography

PURPOSE: To assess dual-detector spiral computed tomographic (CT) arthrography of the knee in the evaluation of anterior cruciate ligament (ACL) tears and associated meniscal lesions. MATERIALS AND METHODS: ACL and meniscal abnormalities in 125 consecutive patients who underwent dual-detector spiral CT arthrography of the knee were evaluated on the basis of both initial interpretations and retrospective review of CT images and were compared with arthroscopic findings. The sensitivity and specificity of CT arthrography for the detection of ACL tears and meniscal lesions in knees with abnormal ACLs were determined. RESULTS: The sensitivities and specificities for the detection of ACL tears were 90% and 96%, respectively, at initial interpretation and 95% and 99%, respectively, at retrospective interpretation. The sensitivities and specificities for the detection of meniscal tears in knees with abnormal ACLs were 92% and 88%, respectively, at initial interpretation and 96% and 94%, respectively, at retrospective interpretation. CONCLUSION: Dual-detector spiral CT arthrography of the knee is an accurate method for detecting ACL tears and associated meniscal lesions.     

Long-term outcome of knee and ankle injuries in elite football

To estimate the risk and evaluate the long-term outcome of knee and ankle injuries in former national team elite football, 69 players were randomly selected, followed by clinical and stress radiographic examinations. Thirty-nine players (49 knees) had had knee injuries and 29 ankle injuries (35 ankles). The median time from injury until study examination was 25 years. The knee injuries were tears of the medial collateral ligament (MCL) in 24 cases combined with rupture of the anterior cruciate ligament (ACL) and meniscus lesions in three. Meniscus lesions had occurred in 17 cases including three combined with ACL and MCL and another two with ACL ruptures. Isolated rupture of the ACL had occurred in four cases. The ankle lesions were in 26 of 35 cases ruptures of the lateral ligaments. In all, 12 players had completely stopped football and three had changed occupation. Signs of arthritis were present in 63% of the injured knees and in 33% of the injured ankles. The incidence of arthritis in the group of 17 uninjured players was 26% in the knee and 18% the ankle. In elite football players knee and ankle injuries seem to have a serious long-term outcome, but also uninjured players have a higher risk of developing arthritis than the normal population.     

Diagnosis of cruciate ligament injury using single contrast arthrography

To evaluate the accuracy of arthrography for assessing the status of the anterior cruciate ligament (ACL), 212 arthrograms from 212 knees in 205 consecutive patients undergoing single contrast arthrography and subsequent arthroscopy or arthrotomy were reviewed. Criteria for evaluation of the ACL included the clarity of its radiographic appearance as well as the anterior laxity of the knee as seen on manual stress views. Of the 111 knees having intact ACLs at surgery, 98 (88%) were evaluated correctly by arthrography. Of the 101 knees having a damaged ACL, 85 were read as torn or attenuated on the arthrogram. When the torn and attenuated ligaments were considered separately, accuracy was decreased. Of the 87 ligaments actually torn, 68 (78%) were read as torn and 9 (10%) as attenuated. Of the 14 actually attenuated, 5 (36%) were read as attenuated and 3 (21%) as torn. Of 114 arthrograms read as intact, 98 (86%) were correct. Of 77 arthrograms read as torn, 68 (88%), were correct. Of 21 arthrograms read as attenuated, 5 (24%) were correct. Of 114 torn medial menisci, 112 (98%) were correctly diagnosed, as were 38 (69%) of 55 torn lateral menisci. Sixteen of the 17 missed lateral meniscus tears were in knees with torn medial menisci. Single contrast arthrography is, therefore, highly accurate in distinguishing intact from damaged ACLs. The distinction between torn and attenuated ligaments, however, is not valuable.     

膝关节前十字韧带撕裂的MRI诊断价值

目的：评价MRI诊断前十字韧带撕裂的价值。方法：对临床拟诊为膝关节前十字韧带撕裂的12例患者，对照分析其MRI资料及手术结果。结果：MRI矢状面9例，冠状面7例显示前十字韧带撕裂。12例中8例前十字韧带内有不规则高信号，4例前十字韧带前缘呈不规则波浪状，1例前十字韧带不连续。12例中6例伴后外侧胜分平台分析。MRI确诊11例。结论：MRI诊断前十字韧带撕裂是有价值的，膝关节后外侧胜管平台分析高度提示急性前十字韧带撕裂。     

The function of the anterior cruciate ligament during anterior drawer and Lachman's testing. An in vivo analysis in normal knees

In order to clarify the function of the anterior cruciate ligament (ACL) during clinical testing an in vivo arthroscopic method of assessing the tension of ACL was developed. Twenty young adult patients with normal knee ligaments and menisci were selected. A spring mechanism in the handle of the specially designed probe allowed the surgeon to apply a known perpendicularly directed force to the ligament while the amount of displacement was observed and recorded. Tension was determined in the anteromedial central and posterolateral portions of ACL before and during an anterior drawer test (knee flexed 90 degrees) and before and during a Lachman's test (knee flexed 15 degrees). The results were consistent in all 20 knees. Baseline tension was greater at 15 degrees of flexion than at 90 degrees. A Lachman's test produced maximal tension in the majority of the ligaments. The anterior drawer did not produce maximal tension in any portion of the ligament. Tension within the anteromedial and central portion of the ligament predominated during both uses. This analysis confirms the specificity of Lachman's test as an indicator of ACL integrity. The concept of two reciprocally functioning ACL "bands" by either anterior drawer or Lachman's test is not supported by our data.