Reliability of magnetic resonance imaging in evaluating meniscal and cartilage injuries in anterior cruciate ligament-deficient knees

Purpose

The accuracy of magnetic resonance (MR) imaging in assessing meniscal and cartilage injuries in anterior cruciate ligament (ACL)-deficient knees as compared to arthroscopy was evaluated in the present study.

Methods

The results of all preoperative MR imaging performed within 3 months prior to the ACL reconstruction were compared against intraoperative arthroscopic findings. A total of 206 patients were identified. The location and type of meniscal injuries as well as the location and grade of the cartilage injuries were studied. The negative predictive value, positive predictive value, sensitivity, specificity and accuracy of MR imaging for these 206 cases were calculated and analysed.

Results

In patients with an ACL injury, the highest incidence of concomitant injury was that of medial meniscus tears, 124 (60.2 %), followed by lateral meniscus tears, 105 (51.0 %), and cartilage injuries, 66 (32.0 %). Twenty-three (11.2 %) patients sustained injuries to all of the previously named structures. MR imaging was most accurate in detecting medial meniscus tears (85.9 %). MR imaging for medial meniscus tears also had the highest sensitivity (88.0 %) and positive predictive value (88.7 %), while MR imaging for cartilage injuries had the largest specificity (84.1 %) and negative predictive value (87.1 %). It was least accurate in evaluating lateral meniscus tears (74.3 %). The diagnostic accuracy of medial meniscus imaging is significantly influenced by age and the presence of lateral meniscus tears, while the duration between MR imaging and surgery has greater impact on the likelihood of lateral meniscus and cartilage injuries actually being present during surgery. The majority of meniscus tears missed by MR imaging affected the posterior horn and were complex in nature. Cartilage injuries affecting the medial femoral condyle or medial patella facet were also often missed by MR imaging.

Conclusion

MR imaging remains a reliable tool for assessing meniscus tears and cartilage defects preoperatively. It is most accurate when evaluating medial meniscus tears. However, MR imaging should be used with discretion especially if there is a high index of suspicion of lateral meniscus tears.

Level of evidence

IV.

     

Meniscal tears on knee arthrography: Patterns of arthrographic abnormalities

The presence or absence of a meniscal tear was established in 340 out of 475 consecutive patients who had double contrast knee arthrograms. The accuracy in these 340 cases was 95% for both the medial and lateral menisci although the specificity for lateral tears was only 0.64. Analysis of the pattern of arthrographic abnormalities revealed that both medial and lateral tears usually involved the posterior horn of the meniscus. Posterior horn abnormalities rarely caused a false positive diagnosis of a meniscal tear. In contrast, isolated blunting of the anterior horn of either the lateral or medial meniscus was an unreliable sign of a tear and accounted for many of the false positive diagnoses. It is concluded that careful attention to the posterior horn of each meniscus is essential for accurate arthrographic diagnosis of a meniscal tear.     

Effect of chondrocalcinosis on the MR imaging of knee menisci

OBJECTIVE: Our goal was to determine the influence of chondrocalcinosis on MR imaging in the detection of meniscal tears. MATERIALS AND METHODS: A retrospective review was performed of knee MR imaging and arthroscopy records from two university hospitals between 1996 and 1998. Seventy individuals had radiographic evidence of chondrocalcinosis and underwent knee MR imaging. Thirty-seven of these individuals had undergone arthroscopy for further evaluation of their symptoms. MR imaging sensitivity and specificity in the detection of medial and lateral meniscal tears were calculated in these 37 patients who had radiographic evidence of chondrocalcinosis and in a control group of 34 patients who underwent MR imaging and arthroscopy but did not have knee chondrocalcinosis. RESULTS: In the chondrocalcinosis group, MR imaging sensitivity, specificity, and accuracy for meniscal tear were 78%, 71%, and 78%, respectively, for the lateral meniscus, and 89%, 72%, and 81% for the medial meniscus. The control group showed sensitivity, specificity, and accuracy of 93%, 100%, and 97%, respectively, for the lateral meniscus and 100% in all cases for the medial meniscus. The MR imaging detection of meniscal tears in both the lateral and medial compartments combined is significantly poorer in the presence of chondrocalcinosis (p < 0.005). CONCLUSION: MR imaging sensitivity and specificity for detection of meniscal tear is decreased in the presence of meniscal chondrocalcinosis. Chondrocalcinosis appeared as a high-signal-intensity region on T1-weighted, intermediate-weighted, and inversion recovery sequences. The high signal of chondrocalcinosis on inversion recovery sequence is an interesting observation that to our knowledge has not been previously reported. Radiographic correlation with the MR imaging examination can help prevent overdiagnosing meniscal tears.     

Discoid lateral meniscus and the frequency of meniscal tears

Objective. To use MRI to determine the incidence of discoid lateral menisci in a large study population, and to compare those patients with those without a discoid meniscus in order to assess the impact of a discoid lateral meniscus on the frequency of meniscal tears. Design and patients. Results of 1250 knee MRI studies were retrospectively reviewed. Using the criterion of three or more meniscal body segments on sequential sagittal images, 56 patients were found to have a discoid lateral meniscus. After exclusion of patients with prior knee surgery, 49 patients with a discoid lateral meniscus were compared with 1146 patients without a discoid meniscus. Patients were categorized as having tears of the medial meniscus, lateral meniscus, or both menisci. Results. In our study population, there was a 4.5% incidence of discoid lateral meniscus. Seventy-one percent of patients with a discoid lateral meniscus had one or more meniscal tears, compared with 54% of the comparison group (P=0.01). The frequency of solitary lateral meniscal tears in the discoid group was also higher than in the comparison group: 20%.versus 11% (P=0.03). The frequency of solitary medial meniscal tears and concomitant tears of both menisci were not significantly different between the two groups. Conclusions. The discoid lateral meniscus is an uncommon variant, but not as rare as once believed. Compared with the normal semilunar meniscus, the discoid lateral meniscus has a higher frequency of meniscal tears, and solitary tears of the lateral meniscus are more common in the discoid variant. The frequency of medial meniscal tears is not altered by the presence of a discoid lateral meniscus. Received: 17 August 2000 Revision requested: 11 December 2000 Revision received: 15 January 2001 Accepted: 16 January 2001     

同种异体半月板移植尺寸匹配的解剖研究

目的:通过解剖测量成人尸体半月板和胫骨尺寸,研究半月板移植进行供体和受体尺寸匹配时,半月板尺寸与胫骨尺寸之间的关系,以判断通过测量胫骨尺寸而计算得出准确半月板尺寸的可行性。方法:对25～45岁的8具成人新鲜尸体的16个膝关节(左膝8个,右膝8个)进行解剖。测量每个膝关节内、外侧半月板的长度和宽度,胫骨内、外侧平台的长度和宽度。对半月板和胫骨平台的测量结果进行比较,并对测量结果进行统计学分析和线性回归分析。对于同一个膝关节,根据回归公式,通过胫骨平台的测量尺寸计算得出理论半月板的尺寸,再将理论半月板的尺寸与实际半月板的测量结果进行比较,得出理论半月板尺寸与实际半月板尺寸误差小于5%的比例。P<0.05定义为具有显著性差异。结果:测量的16个膝关节的内侧半月板宽度为(29.2±2.1)mm,内侧胫骨平台宽度(33.8±2.1)mm,P<0.001;内侧半月板的长度(39.8±4.1)mm,内侧胫骨平台长度(50.6±2.0)mm,P<0.001;外侧半月板宽度(30.9±2.2)mm,外侧胫骨平台宽度(33.7±1.6)mm,P<0.001;外侧半月板长度(33.3±2.5)mm,外侧胫骨平台长度(46.8±2.5)mm,P<0.001。根据半月板尺寸与胫骨平台尺寸之间的线性回归公式,计算所得的理论半月板尺寸比同一膝关节半月板实际解剖测量尺寸误差小于5%的符合率为:内侧半月板宽度50%,内侧半月板长度31.25%,外侧半月板宽度75%,外侧半月板长度56.25%。结论:在半月板移植前进行受体和供体半月板尺寸匹配时,不能通过测量患者胫骨平台的尺寸代替所需要半月板移植物的尺寸。通过本研究16例膝关节半月板尺寸与胫骨尺寸之间的线性回归公式不能获得理想的半月板移植物尺寸。     

The O'Donoghue triad revisited. Combined knee injuries involving anterior cruciate and medial collateral ligament tears

We identified 60 consecutive patients with combined anterior cruciate and medial collateral ligament (ACL-MCL) disruptions that were incurred during athletic endeavors. Each underwent acute reconstruction of the ACL. The arthroscopic data obtained at the time of reconstructive surgery was reviewed in order to determine the incidence of O'Donoghue's triad (the "unhappy triad"), consisting of ACL, MCL, and medial meniscus tears. Patients were subdivided into two groups for analysis based upon the degree of MCL injury at time of presentation (Group I, 35 patients with a second-degree sprain; Group II, 25 patients with a complete, or third-degree injury). Medial meniscus tears were an uncommon finding. Lateral meniscus tears significantly out-numbered medial meniscus tears in both groups, occurring in 25 (71%) of Group I patients and 8 (32%) of those in Group II. Even chondral fractures of the lateral femoral condyle outnumbered medial meniscus tears [6 (17%) versus 4 (11%)] in patients with a second-degree MCL sprain. Furthermore, when present in Group I patients, tears of the medial meniscus were associated with a concomitant lateral meniscus injury. Group II patients were more likely (60%) than Group I not to have any meniscal abnormality at all. We conclude that the classic O'Donoghue triad is, in fact, an unusual clinical entity among athletes with knee injuries; it might be more accurately described as a triad consisting of ACL, MCL, and lateral meniscus tears. This injury combination appears to be more common when an incomplete, or second-degree, tear of the medial collateral has occurred.(ABSTRACT TRUNCATED AT 250 WORDS)     

0.2-Tesla magnetic resonance imaging of internal lesions of the knee joint: a prospective arthroscopically controlled clinical study

The results of magnetic resonance imaging (MRI) were compared with those of arthroscopy in a prospective series of 244 patients. A dedicated system for MRI of limbs and peripheral joints – the 0,2-T Artoscan (Esaote, Italy) – was used for imaging knee joint lesions. T1-weighted spin-echo sagittal images, T2-weighted gradient-echo coronal images, and axial views for lesions of the femoropatellar joint were acquired. Paraxial sagittal and oblique coronal views were obtained for imaging of the cruciate ligaments. This protocol allowed excellent visualization of the cruciate ligaments and medial and lateral meniscus in almost all patients. Compared with arthroscopy performed within 48 h after imaging, the sensitivity, specificity, and accuracy were respectively 93%, 97%, and 95% for tears of the medial meniscus; 82%, 96%, and 93% for tears of the lateral meniscus; 100%, 100%, and 100% for tears of the posterior cruciate ligament; 98%, 98%, and 97% for tears of the anterior cruciate ligament; and 72%, 100%, and 92% for full-thickness articular cartilage lesions. The examination can be performed within 30–45 min at lower cost than diagnostic arthroscopy. MRI with a 0.2-T magnet is a safe and valuable adjunct to the clinical examination of the knee and an aid to efficient preoperative planning. Received: 13 October 1997 Accepted: 3 March 1998     

Usefulness of 99Tcm-MDP knee SPET for pre-arthroscopic evaluation of patients with internal derangements of the knee

The aim of this study was to ascertain whether knee SPET can localize lesion sites in patients with internal derangements of the knee. We performed knee SPET as a pre-arthroscopic examination in 63 consecutive patients. SPET imaging was performed with a triple-headed SPET camera 4 h after the injection of 99Tcm-methylene diphosphonate. Arthroscopic diagnoses were as follows: 28 medial meniscus injuries, 24 lateral meniscus injuries, 31 anterior cruciate ligament (ACL) injuries, three posterior cruciate ligament injuries and one medial collateral ligament injury. Of 30 patients with crescent-shaped increased activity at the medial tibial plateau, 22 had medial meniscus injuries (positive predictive value: PPV 73%); of 17 patients with crescent-shaped activity at the lateral tibial plateau, 13 had lateral meniscus injuries (PPV 76%). Of 18 patients with increased activity at ACL attachment sites (primary sign), 17 had ACL injuries (PPV 94%). Of 27 patients with increased activity at bone impaction sites of ACL injury (secondary sign), 22 had ACL injuries (PPV 81%). Of 32 patients who had either a primary or secondary sign, 26 had ACL injuries (PPV 81%). We conclude that knee SPET is very useful in the management of internal derangements of the knee, particularly in determining the need for arthroscopy by localizing lesion sites.     

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.     

Relationship between bone bruise volume and the presence of meniscal tears in acute anterior cruciate ligament rupture

Purpose

To determine whether there is a relationship between the size of the bone bruise volume after an acute anterior cruciate ligament (ACL) rupture and the presence of meniscal tears in the medial and lateral compartment.

Methods

Following Institutional Review Board approval, 50 patients with an acute ACL rupture and MRI imaging within 30 days of injury were identified. Two musculoskeletal radiologists evaluated the lateral and medial menisci and graded them as one of the following: no meniscal tear, tear of one meniscus (medial or lateral) or tear of both menisci (medial and lateral). Sagittal T2 fat-suppressed images were used to calculate bone bruise volume. The relationship between bone bruise volume and the presence of a meniscus tear was calculated.

Results

Forty-three (86 %) patients had a bone bruise, 16 (32 %) patients had no tear, 7 (14 %) patients had lateral meniscus tear, 13 (26 %) patients had medial tear and 14 (28 %) patients had medial and lateral tears. There was a statistically significant difference in femoral bone bruise volume when comparing no meniscal tear to medial and lateral tears as well as when comparing medial or lateral tears to medial and lateral tears.

Conclusion

There is a statistically significant relationship between femoral bone bruise volume and the presence of meniscal tears in ACL injury, especially in the setting of medial and lateral pathology.

Level of evidence

Retrospective cohort study, Level III.     

MR imaging of the knee at 0.2 and 1.5 T: correlation with surgery

OBJECTIVE: The purpose of this study was to compare the diagnostic efficacy of low- and high-field-strength MR imagers in the diagnosis of anterior cruciate ligament tears and meniscus tears. SUBJECTS AND METHODS: In 219 patients with suspected internal derangement of the knee, MR imaging at 0.2 and 1.5 T was performed with similar sequences. Only patients with surgically confirmed diagnosis (n = 90) were included in the statistical analysis. Radiologists were unaware of diagnosis and field strength. Sensitivity, specificity, diagnostic accuracy, and inter- and intraobserver variability were determined. RESULTS: There was excellent correlation between the field strengths in accuracy, sensitivity, and specificity for anterior cruciate ligament and meniscus tears. Accuracy for medial meniscus, lateral meniscus, and anterior cruciate ligament tears was 91-93%, 88-90%, and 93-96%, respectively, at 0.2 T and 91-94%, 91-93%, and 97-98%, respectively, at 1.5 T. Inter- and intraobserver variability values showed excellent correlation (kappa > 0.8). CONCLUSION: The level of diagnostic accuracy in anterior cruciate ligament tears and meniscus tears is comparable for low- and high-field-strength MR imagers.     

Magnetic resonance imaging as a tool to predict reparability of longitudinal full-thickness meniscus lesions

Prediction of meniscus reparability is useful for surgeons to optimise surgical scheduling and to inform patients about postoperative management. This study was designed to determine the accuracy of MRI in predicting the reparability of longitudinal full-thickness meniscus lesions. We studied 100 MRIs of longitudinal full-thickness medial or lateral meniscus lesions located from the meniscosynovial junction to the axial part of the meniscus. The MRI criteria of reparability were a peripheral rim smaller than 4 mm and a lesion longer than 10 mm. At arthroscopy the menisci were considered as reparable when the lesion was located in red–red or red–white zones and when it was more than 1 cm in length. A heterogeneous or homogeneous aspect of the meniscus body was also considered. The length of the meniscus lesion averaged 17.6 mm and the thickness of the rim 3.4 mm. A heterogeneous signal of the axial fragment and of the rim was found in 11 cases and in 48 cases, respectively. In 90 cases, there was no difference between the MRI-predicted reparability and the arthroscopic findings. Global sensitivity of MRI to determine reparability of full-thickness meniscus lesions was 94%, increasing to 96% for the medial meniscus and dropping to 83% for the lateral meniscus. Global specificity was 81%, and was higher for the lateral meniscus (90%) than for the medial one (82%). Global positive predictive value was 0.94 and global negative predictive value was 0.82. A heterogeneous aspect of the rim did not compromise arthroscopic reparability whereas a heterogeneous aspect of the axial fragment indicated an irreparable meniscus. The described MRI criteria can predict meniscus reparability. Their accuracy is limited for lateral meniscus lesions close to the popliteal hiatus and for very young active patients in whom repair of white–white lesions can be attempted. Longitudinal full-thickness meniscus lesions are a good indication for repair in young active patients.     

膝关节半月板周缘性移位 MRI 诊断与分析

目的：应用 MRI 观察半月板周缘性移位现象,确定半月板周缘性移位严重程度与膝关节周围结构的关系,探讨其临床意义。方法回顾分析148例患者膝关节 MRI 检查图像,将患者按年龄大小分为中青年组、中老年组、老年组,以半月板关节囊缘超出胫骨平台边缘定义为半月板周缘性移位,以膝关节内侧半月板与膝关节内侧副韧带、外侧半月板与髂胫束之间的位置关系来确定半月板移位的严重程度。结果148例患者半月板移位总发生率为48.6%(72/148),中青年组发生率为34.8%(8/23)、中老年组发生率为46.1%(35/76)、老年组发生率为59.2%(29/49),各年龄组间比较差异有统计学意义(χ2=4.15,P <0.05),半月板移位发生率随年龄增加而增加,移位程度随年龄增加而严重。结论半月板移位及严重程度与患者年龄密切相关;以膝关节内、外侧半月板与内侧副韧带、外侧髂胫束之间的位置关系来确定半月板移位严重程度有重要的临床意义。     

Meniscal position on routine MR imaging of the knee

 Objective. To determine the prevalence of meniscal protrusion (i.e. location of the outer edge of a meniscus beyond the tibial articular surface), and to determine its relationship with internal derangement, joint effusion, and degenerative arthropathy. Design and patients. Sagittal and coronal MR images of 111 abnormal and 46 normal knees were evaluated for the presence of meniscal protrusion. We set 25% as the minimum amount of displacement considered abnormal because this was the smallest amount of displacement we could confidently discern. Presence of meniscal tear, anterior cruciate ligament (ACL) injury, joint effusion, or osteophytosis was also recorded. Results and conclusion. Normal examinations demonstrated protrusion of the medial meniscus in 6.5% of sagittal images and 15% of coronal images, and of the lateral meniscus in 2% and 13%, respectively. Fisher’s exact test demonstrated a statistically significant difference between the normal and abnormal groups for the medial meniscus on both sagittal (P<0.0001) and coronal (P=0.01) images, but not for the lateral meniscus in either plane (P>0.2). A protruding medial meniscus was associated with effusion and osteophytosis (P<0.05) but not with meniscal or ACL tear (P>0.1). Posterior protrusion of the lateral meniscus was only associated with ACL injury (P<0.0001); protruding anterior horns and bodies of lateral menisci were not associated with any of the four abnormalities. It is concluded that the medial meniscus may occasionally protrude more than 25% of its width, but protrusion is more often due to effusion and osteophytes. Protrusion of the posterior horn of the lateral meniscus is associated with ACL insufficiency, while protrusion of the body and anterior horn of the lateral meniscus is a normal variant.     

Significance of the arthroscopic meniscal flounce sign: a prospective study

BACKGROUND: The meniscal flounce sign is a fold in the free, nonanchored inner edge of the medial meniscus that can be noted during routine arthroscopy of the knee. HYPOTHESIS: The meniscal flounce sign can be a significant indicator of the presence or absence of medial meniscus injury. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 4. METHODS: One hundred sixty-eight patients were prospectively evaluated at the time of the arthroscopy for the presence or absence of the arthroscopic meniscal flounce sign. These results were then correlated with the presence of medial meniscus tears. RESULTS: The presence of the meniscal flounce sign has a positive predictive value of a normal meniscus of 0.97 (63/65). The absence of the meniscal flounce sign has a positive predictive value of an abnormal meniscus of 0.98 (101/103). Specificity is 98%, and sensitivity is 97%. CONCLUSION: The absence of the arthroscopic meniscal flounce sign is a sensitive and specific predictor of the presence of medial meniscus tears that should alert the surgeon to probe carefully for an occult medial meniscus tear.     

膝关节半月板囊肿22例MRI分析

目的：分析膝关节半月板囊肿的MRI特点，提高对该病的认识。方法：回顾性分析22例膝关节半月板囊肿的MRI表现并与关节镜或手术结果对照。探讨半月板囊肿发生的部位、形态、信号特征及与半月板的毗邻关系。结果：22例半月板囊肿中，内侧半月板囊肿4例(18．1％)，外侧半月板囊肿18例(81．8％)。22例半月板囊肿中显示半月板水平撕裂15例(68．2％)，纵行撕裂3例(18．1％)。结论：半月板囊肿好发于外侧半月板，并与半月板的撕裂相关，表明MRI对诊断半月板囊肿有较高的临床价值。     

Atypically thick and high location of the Wrisberg ligament in patients with a complete lateral discoid meniscus

The purpose of this study was to document the relationship between a discoid lateral meniscus and a thickened Wrisberg ligament with a higher location on the medial femoral condyle.Between July 2002 and February 2006, 100 consecutive patients who had a complete lateral discoid meniscus and another 100 patients without a discoid lateral meniscus (control group) were included. Two radiologists retrospectively reviewed all of the magnetic resonance images, paying particular attention to the presence and thickness of the Wrisberg ligament and the location of the attachment of the Wrisberg ligament to the medial femoral condyle (types I, II, or III). We assumed that type I Wrisberg ligaments had a higher location.All 141 patients had a Wrisberg ligament (71%). There were 73 patients (73%) in the discoid group and 68 patients (68%) in the non-discoid group. The mean thickness of the Wrisberg ligament in the patients in the discoid and non-discoid groups was 2.1 mm (range, 0.4-4.7 mm; median, 2.1 mm) and 1.6 mm (range, 0.4-4.5 mm; median, 1.3 mm), respectively. The Wrisberg ligaments of the discoid group were thicker than the non-discoid group (p = 0.0002). The Wrisberg ligament was attached to the upper part of the medial femoral condyle in the discoid group more often than in the non-discoid group (p < 0.0001).     

急性非接触性前交叉韧带撕裂后关节伴随损伤的性别差异

 目的 对比分析急性非接触性前交叉韧带(ACL)撕裂后关节伴随损伤男女性别组间的不同点。方法 回顾性分析193例经临床证实为急性非接触性ACL撕裂患者的MRI资料,其中男性112例,女性81例,对男女性别组的膝关节伴随损伤情况分类统计并进行统计学分析。结果 在112例男性病例中,发现骨挫伤107例(95.5%),其中联合间室骨挫伤32例,外侧间室骨挫伤70例,内侧间室骨挫伤5例;81例女性病例中,发现骨挫伤72例(88.9%),其中联合间室骨挫伤16例,外侧间室骨挫伤49例,内侧间室骨挫伤7例;两组比较,联合间室骨挫伤发生率差异有统计学意义(χ²=4.315,P=0.038)。男女组伴发内外侧半月板(MM、LM)损伤发生率分别为(33.9%、46.4%)和(25.9%、32.1%),两组比较,LM损伤发生率差异有统计学意义(χ²=4.008,P=0.045)。男女组伴发内、外侧副韧带损伤发生率分别为(20.5%、7.1%)和(18.5%、3.7%),两组比较,差异均无统计学意义。男女组伴发关节软骨损伤发生率为17.9%和7.4%,两组比较,差异有统计学意义(χ²=4.403,P=0.036)。结论 男性患者较女性患者在急性非接触性ACL撕裂后更易伴发联合间室骨挫伤、LM损伤和关节软骨损伤。     

Accuracy of MR imaging of the knee in adolescents

OBJECTIVE: A report in the orthopedics literature states that MR imaging for internal derangement of the knee has a lower accuracy in adolescents than in adults and may even provide spurious information that alters clinical management. This assertion has not been specifically addressed in the radiology literature. The purpose of our study was to determine the accuracy of MR imaging in adolescents with regard to injury of the cruciate ligaments and menisci. MATERIALS AND METHODS: A database search of our institution's records from January 1998 to July 2000 yielded 2140 MR examinations of the knee, all of which had been performed with a standard knee protocol on a 1.5-T magnet. Of these 2140 examinations, 156 included patients younger than 18 years. Fifty-nine of these patients underwent surgery, and the orthopedic surgeons' operative reports were used as the gold standard with which the MR imaging results were compared. Thirty-four boys and 25 girls who ranged in age from 11 to 17 years (mean age, 15 years) were examined. The clinical notes for the remaining 97 patients were evaluated for information about management and clinical improvement. RESULTS: The sensitivity and specificity values for MR imaging of the menisci and cruciate ligaments in adolescents were as follows: medial meniscus, 92% sensitivity and 87% specificity; lateral meniscus, 93% sensitivity and 95% specificity; anterior cruciate ligament, 100% sensitivity and 100% specificity; and posterior cruciate ligament, 0% sensitivity and 100% specificity. CONCLUSION: Our data suggest that MR imaging of the knee in adolescents is sensitive, specific, and accurate.     

Association of gastrocnemius tendon calcification with chondrocalcinosis of the knee

 Objective. Chondrocalcinosis of the knee is a common radiological finding in the elderly. However, visualization of chondrocalcinosis may be difficult in patients with advanced cartilage loss.The purpose of this study was to determine sensitivity, specificity, and accuracy of gastrocnemius tendon calcification that might serve as a radiographic marker of chondrocalcinosis in patients with painful knees. Design and patients. We prospectively evaluated 37 knee radiographs in 30 consecutive patients (29 men, 8 women; mean age 67 years, age range 37–90 years) with painful knees who had radiographic evidence of chondrocalcinosis. The frequency of fibrocartilage, hyaline cartilage, and gastrocnemius tendon calcification was determined. For a control group, we evaluated knee radiographs in 65 consecutive patients with knee pain (54 men, 11 women; mean age 59 years, age range 40–93 years) who had no radiological signs of chondrocalcinosis. The frequency of gastrocnemius tendon calcification in the control group was determined. Results. Gastrocnemius tendon calcification was 41% sensitive, 100% specific, and 78% accurate in predicting chondrocalcinosis. The gastrocnemius tendon was calcified on 15 of 37 (41%) radiographs in the experimental group and on 0 of 67 radiographs in the control group. In the chondrocalcinosis group, 23 (62%) had posterior hyaline cartilage calcification, 14 (38%) had anterior hyaline cartilage calcification, 31 (84%) had medial meniscus calcification, and 36 (97%) had lateral meniscus calcification. Conclusions. Our results show that gastrocnemius tendon calcification is an accurate radiographic marker of chondrocalcinosis in patients with knee pain.