Characteristics of displaceable and nondisplaceable meniscal tears at kinematic MR imaging of the knee

PURPOSE: To prospectively determine if kinematic magnetic resonance (MR) imaging of the knee may demonstrate displacement of menisci with tears and, if so, to characterize displaceable and nondisplaceable meniscal tears. MATERIALS AND METHODS: The study was approved by the hospital's review board, and informed consent was obtained. Forty-two patients (30 men, 12 women; mean age, 36.9 years) with 43 arthroscopically documented meniscal tears visible at 1.5-T MR imaging underwent kinematic MR imaging with an open-configuration 0.5-T MR imager with their knees in supine neutral, supine with 90 degrees flexion and external or internal rotation, and upright weight-bearing positions. Analysis of meniscal movement was performed in different knee positions in the coronal MR imaging plane. Meniscal displacement--that is, meniscal movement of 3 mm or more (in the medial direction for the medial meniscus, in the lateral direction for the lateral meniscus)--was compared with the patient's pain level as assessed with a visual analog scale by using analysis of variance. RESULTS: Between the different knee positions, meniscal displacement of 3 mm or more (displaceable meniscal tears) was noted in 18 (42%) of 43 menisci with tears. Simultaneous occurrence of grade II or III ipsilateral collateral ligament lesions was present in all 18 displaceable meniscal tears, whereas a normal-appearing collateral ligament or collateral ligament lesion (grade I) was present in 22 of 25 nondisplaceable tears (P < .05). Displaced menisci most commonly had complex, radial, or longitudinal tear configurations (16 of 18, 89%). Patients with displaceable meniscal tears had significantly more pain than did patients with nondisplaceable meniscal tears (P < .001), independent of the concomitant knee abnormalities. CONCLUSION: Displaceable meniscal tears usually have longitudinal, radial, or complex configurations; such tears are associated with substantial ipsilateral collateral ligament lesions and pain.     

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.     

Meniscal tears: role of axial MRI alone and in combination with other imaging planes

OBJECTIVE: The purpose of this study was to determine the reliability of standard axial MR images alone in the diagnosis of meniscal tears of the knee and in combination with other imaging planes. MATERIALS AND METHODS: Sixty-two patients (55 men, seven women; age range, 23-68 years) with a prior MRI examination who underwent arthroscopic surgery of the knee during a 1-year period were included in the study group. Images were independently reviewed for identification of meniscal tears by two musculoskeletal radiologists blinded to arthroscopic findings. Sequences for meniscal evaluation included axial fat-saturated fast spin-echo proton density, coronal fat-saturated fast spin-echo proton density, and sagittal fast spin-echo proton density with 4- to 5-mm slice thicknesses. Imaging groups for evaluation were axial, coronal, sagittal, axial and sagittal, axial and coronal, and coronal and sagittal. Observers reported a confidence level for the presence or absence of meniscal tear in all imaging groups based on a 5-point scale. Statistical analysis considered medial and lateral menisci separately. RESULTS: Forty patients had medial meniscal tears, and 16 had lateral meniscal tears at arthroscopy. For medial and lateral meniscal tears, the accuracy (79% and 71%, respectively) of imaging in the axial plane was comparable to other imaging groups but the mean confidence levels (2.82 and 3.00, respectively) were low. In one patient, the axial plane alone correctly showed that no tear was present. No statistically significant difference was observed between imaging plane groups of both menisci in the diagnosis of meniscal tears (p > 0.05). The axial plane increased the accuracy of sagittal and coronal planes of lateral meniscus when combined. CONCLUSION: In standard knee MRI examinations, the axial imaging plane may be valuable for the detection and characterization of meniscal tears.     

The evaluation of intraarticular lesions accompanying ACL ruptures in military personnel who elected not to restrict their daily activities: the effect of age and time from injury

The purpose of this study was to evaluate arthroscopically the type, localization and prevalence of the meniscal and chondral lesions accompanying complete rupture of the anterior cruciate ligament (ACL) in patients who elected not to restrict their daily activities after the initial trauma. The size of the chondral lesions was also evaluated. Our second aim is to analyze the effects of age, time from injury, and both age and time from injury in the presence or absence of accompanying lesions in these patients. The localization and type of the accompanying lesions of 317 knees with complete rupture of the ACL were recorded by the same observer. We applied therapeutic arthroscopy to all patients after their first visit to our clinic. All of the patients were military personnel and their history revealed that they had elected to not restrict their occupational activities after the first trauma causing ACL insufficiency. We defined the first 6 week period after the initial trauma as the acute, 6 weeks to 12 months as the subchronic and 12 months or longer as the chronic period. The average time from injury to arthroscopy for these patients, who were all male, was 19.4 ± 20.3 months. Eighty-one percent of the patients had at least one meniscal tear, and 45.1% had at least one chondral lesion. The mean ages at the time of surgery of patient groups with or without medial and lateral menisci lesions were compared, and no statistically significant difference was determined. In the chronic period, the relative risk (RR) values of meniscal tears were 7.75 for medial and 2.40 for lateral. The group consisting of patients with chondral lesions was compared with the group of patients without chondral lesions in terms of their ages and the time from injury to arthroscopy, and the difference was statistically significant. The RR value for patients with co-existence of at least two lesions was 1.761 for more than 30 years of age. The RR values for at least two lesions were 2.356 for the subchronic and 14.909 for the chronic group when compared to the acute group. The RR values in patients more than 30 years of age in the chronic group were 13.58 for medial meniscus, 3.21 for lateral meniscus and 71.88 for chondral lesions when compared to patients less than 30 years of age in the acute group. It is important to note that the combined effects of advanced age and prolonged time from injury in patients who elected to not restrict occupational activities are more severe due to the increase in the occurrence of intraarticular lesions accompanying ACL insufficiency as compared to their separate effects.A part of this study was given as an oral presentation at the XIX National Orthopedic and Traumatology Congress in May 2005.     

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     

Medial and lateral meniscal tear patterns in anterior cruciate ligament-deficient knees. A prospective analysis of 575 tears

We used our database to evaluate the locations of meniscal tears associated with anterior cruciate ligament injuries. Five hundred seventy-five meniscal tears were seen in 476 patients. Each tear was categorized prospectively according to the side (medial/lateral), the radial zone of the tear, and the circumferential zone of the tear. The different tear locations were then compared for the medial and lateral menisci and evaluated for statistical significance. We found a nearly equal number of tears on the medial (305) and lateral (270) sides. A significantly greater number of tears on the medial side as compared with the lateral side were posterior (99.4% versus 87.8%) and peripheral (75.4% versus 44.1%). Peripheral posterior horn tears of the medial meniscus were the most common type of tear (230 of 575, 40%) by a statistically significant amount.     

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.     

Do asymptomatic marathon runners have an increased prevalence of meniscal abnormalities? An MR study of the knee in 23 volunteers

Excessive repetitive musculoskeletal loads and stresses associated with intense physical activity may lead to deterioration of the menisci of the knee. Therefore, MR imaging was performed on the knees of 23 asymptomatic marathon runners (eight men, 15 women; average age, 40 years; average number of years training, 10; average training distance per week, 41 miles) to determine the prevalence of meniscal signal abnormalities. None of the runners had previous knee injuries or surgery and each of them regularly competes in 26-mile, 50-mile, or 100-mile marathon races. T1-weighted coronal MR images and proton density-weighted and T2-weighted sagittal images were obtained with a 1.5-T MR system and a transmit/receive extremity coil. The medial and lateral menisci were divided into four portions, or horns, and a total of 92 horns were evaluated (i.e., four horns per knee: medial posterior, medial anterior, lateral posterior, and lateral anterior). Two meniscal horns (2%) had grade 3 signal (grade 3 indicates a meniscal tear), 12 (13%) had grade 2 signal, 29 (32%) had grade 1 signal (grades 1 and 2 are indicative of meniscal degeneration), and 49 (53%) had grade 0 signal (grade 0 is normal). Overall, the prevalence of meniscal tears was 9% (two meniscal tears found in 23 runners). This is lower than the prevalence of MR signal abnormalities indicative of meniscal tears reported for asymptomatic, nonrunner athletes (20% of 20 athletes) and for asymptomatic nonathletes (16% of 74 subjects). Fifty-three percent of the meniscal horns of the nonrunner athletes had grade 1 or 2 signal, indicative of meniscal degeneration. Our results indicate that the prevalence of meniscal tears in marathon runners is no higher than the prevalence reported for sedentary persons, and the runners have the same amount of meniscal degeneration as do nonrunner athletes.     

半月板可疑撕裂的MRI与关节镜对照研究

研究半月板可疑撕裂的出现机率及其临床意义。材料和方法：回顾性分析了１２６个膝关节的ＭＲ扫描资料，当二位放射科医生均不能肯定半月板内的高信号是否延伸至半月板表面时，诊断为半月板可颖撕裂，并与关节镜检查结果进行对照。结果：１２６例中有２２例诊断为半月板可疑撕裂，占１７．５％。１２例位于内侧半月板的后角，４例位于外侧半月板的前角，６例位于外侧半月板的后角。２２例中１８例作了关节镜检查，只有２例发现有撕裂     

Bony morphology of the knee and non-traumatic meniscal tears: Is there a role for meniscal impingement?

Objective

Meniscal tears are an important cause of morbidity. The aim of this study was to examine the relationship between non-traumatic meniscal tears and the intrinsic bony morphology of the knee.

Methods

A retrospective analysis of 160 knee MRI scans in 150 patients was carried out who met the following criteria: (a) age between 20 and 45 years, (b) no history of knee trauma, surgery, infection, metabolic bone disease, and (c) no collateral or cruciate ligamentous injury. The medial tibial slope (MTS), lateral tibial slope (LTS), medial tibial plateau depth (MTPD), and medial and lateral femoral condylar offset ratios were calculated. The anterior horn, body, and posterior horn of the menisci were graded as 0 (no tear), 1 and 2 (degenerative changes), or 3 (definitive tear). One-way ANOVA and linear regression was used for statistical analysis.

Results

In patients with grade 3 tears of the posterior horn of the medial meniscus, there was a significant association with shallower MTS (p?<?0.05), smaller medial femoral offset ratio (p?<?0.05) and smaller lateral femoral offset ratio (p?<?0.05). Patients with grade 3 tears of anterior horn of the lateral meniscus had a significant association with shallower LTS (p?<?0.05). No significant association was seen between MTPD and meniscal tears.

Conclusions

Our results suggest an association between bony morphology of the knee and non-traumatic meniscal tears. Shallower MTS and LTS may result in impingement of posterior horn of medial meniscus and anterior horn of lateral meniscus, respectively. Future kinematic studies will be needed to help confirm our findings.     

Abnormal superior popliteomeniscal fascicle and posterior pericapsular edema: indirect MR imaging signs of a lateral meniscal tear

OBJECTIVE. Because MR diagnosis of lateral meniscal tears can be difficult, indirect signs may be useful when a tear is suspected. We studied whether an abnormality of the superior popliteomeniscal fascicle or pericapsular edema was associated with lateral meniscal tears and thus may be an indirect MR imaging sign of a lateral meniscal tear. MATERIALS AND METHODS. We identified 59 consecutive patients who underwent both knee MR imaging examinations and knee arthroscopy. Thirty patients had lateral meniscal tears, and 29 had intact lateral menisci. We reviewed paired sagittal proton density- and T2-weighted MR images from these 59 patients for abnormal superior popliteomeniscal fascicles and edema surrounding the posterolateral capsule. RESULTS. The superior popliteomeniscal fascicles were abnormal in nine of the 30 patients with torn lateral menisci but were normal in all 29 patients with intact menisci (p = 0.001). Abnormal fascicles were apparent only when the lateral meniscal tear involved the posterior horn. Posterior pericapsular edema was seen in 10 patients with a torn posterior horn and in one patient with an anterior horn tear of the lateral meniscus, but in only two patients with intact menisci (p = 0.006). CONCLUSION. The presence of superior popliteomeniscal fascicle abnormalities and of posterior pericapsular edema is significantly associated with a tear of the lateral meniscus, most commonly in the posterior horn. Noting the presence of these findings may help improve the accuracy of MR diagnosis of lateral meniscal tears.     

Healing potential of meniscal tears without repair in knees with anterior cruciate ligament reconstruction

BACKGROUND: Few previous studies have documented the healing potential of meniscal tears that are left to heal without repair. PURPOSE: To determine the healing rates of meniscal tears left without repair in knees with anterior cruciate ligament reconstruction. STUDY DESIGN: Prospective cohort study. METHODS: One hundred and ninety-two knees were evaluated at the time of anterior cruciate ligament reconstruction and repeat arthroscopy. The healing rates of 41 medial and 42 lateral torn menisci without repair were evaluated by the same 2 surgeons in an identical fashion. RESULTS: Of 41 medial torn menisci left without repair, 22 (56%) were considered completely healed, 3 (7%) were incompletely healed, 11 (24%) were unhealed, and 5 (10%) had expanded unhealed lesions. Of 42 lateral torn menisci, 31 (74%) were considered completely healed, 2 (5%) were incompletely healed, 6 (14%) were unhealed, and 3 (7%) had expanded unhealed lesions. The healing rate of a medial meniscal tear was length dependent and not related to reconstructed ligament stability. CONCLUSIONS: Stable meniscal tears at the time of anterior cruciate ligament reconstruction possibly could be left in situ. However, longer medial meniscal tears are thought to require additional stabilizing procedures.     

Healing results of meniscal tears left in situ during anterior cruciate ligament reconstruction: a review of clinical studies

The presence of peripheral meniscal tears is common at the time of anterior cruciate ligament (ACL) reconstruction. Techniques to preserve the maximum amount of meniscal tissue include “non operative” management (tear left alone, without repair or removal), meniscus repair, partial meniscectomy. There is a lack of consensus guidelines about the management of peripheral stable meniscal tears. When to remove, let alone or repair? We performed an evidence-based review of the outcomes of stable meniscal tears left in situ during ACL surgery, in order to assess the effectiveness of this popular procedure. Clinical and anatomical results (arthrography or second look arthroscopy) were analyzed. Our literature search yielded ten relevant studies (9 level IV, 1 level III). The mean time of follow-up was 16 months. Pain or mechanical symptoms related to the medial tibiofemoral joint were reported in 0–66% of cases. Subsequent medial meniscectomy or repair were performed in 0–33% of cases. Pain or mechanical symptoms related to the lateral tibiofemoral joint were reported in 0–18% cases. Subsequent lateral meniscectomy or repair were performed in 0–22% cases. A complete healing occurred in 50–61% cases for the medial meniscus and in 55–74% cases for the lateral meniscus. No definite conclusion can be made with regard to these results. The conservative approach is more effective for lateral menisci. The rate of bad results for the medial meniscus remains high when a conservative treatment is used. For the medial meniscus, repair of stable peripheral tears may be always indicated to decrease the risk of postoperative pain or subsequent meniscectomy.     

Clinical and arthroscopic features of meniscal tears and a search for the role of infection in histologically confirmed meniscal mucoid degeneration

Mucoid degeneration (MD) of the meniscus has received little attention. The pathology deserves special interest as it may lead to loss of the meniscus even in very young individuals. The cause of MD and the clinical features of meniscal tears due to that pathology have not been understood. This study analyzed the age profile and the role of trauma in patients with torn menisci with MD, examined meniscal tear patterns and clinical features, and investigated the role of bacterial infection in causing MD. Meniscal samples obtained from 27 consecutive patients during arthroscopic resection of torn menisci considered to be due to MD (typical yellow color) underwent pathological investigation. The samples were scored according to the light microscopic criteria of Copenhaver; 24 menisci (23 patients) with stage 2–3 MD comprised the study group. Magnetic resonance imaging obtained in 11 patients typically revealed increased intrasubstance signal intensity that extended to at least one of the meniscal surfaces. Pieces of resected meniscal tissue were also subject to PCR investigation to search for presence of bacteria. Of the 24 knees 21 (87%) had no history of trauma. Mean Tegner activity level was 4 (1 and 7). Mean duration of symptoms was 11.6 months (1–36). Pain was the most frequent symptom (n=22). Joint line tenderness and McMurray's test (pain and/or clicking) were present in 22 and 16 knees, respectively. Medial meniscus was affected in 16 and lateral meniscus in 8. Meniscal cyst and incomplete discoid meniscus was present in 5 and 2 of the lateral menisci. All of the torn menisci were degenerated and yellow in color. The most common tear patterns were radial and/or flap, and longitudinal-horizontal tears. PCR study revealed no bacteria. Mucoid degeneration of the meniscus does not seem to be related to the aging process. Clinical findings of torn such menisci are insidious compared to traumatic tears. Lack of history of trauma may delay the diagnosis. Bacterial infection has no role in the cause.     

Three-dimensional axial volume acquisition on meniscal lesions of the knee]

Axial three-dimensional volume scans obtained by magnetic resonance (MR) imaging were used to evaluate meniscal lesions of the knee in 28 knees of 26 cases. Axial 0.7 mm thin-sliced images with volume scan outlined the overall meniscal appearance for the first time. Axial volume scan was essential to the diagnosis of discoid lateral meniscus because only it could depict the characteristic elongated appearance of discoid lateral meniscus. Radial meniscal tears were depicted only by this technique: conventional sagittal and coronal views could not detect this type of meniscal tear. Volume scan could detect the precise extent of lesions with horizontal meniscal tears and meniscal degeneration. These MR findings obtained by axial volume scans were confirmed by arthroscopy in all cases. We concluded that volume scans were extremely useful in the evaluation of meniscal lesions because they offered axial views that provided much information on menisci located horizontally in the knee.     

Meniscal bucket handle tears: a retrospective study of arthroscopy and the relation to MRI

In this study, we aim to evaluate the arthroscopic findings of meniscal bucket handle tears and to correlate them with the proposed MR imaging signs of meniscal bucket handle tears suggested in the literature. Thirty-six patients who had a diagnosis of bucket handle tear in arthroscopy, in either medial or lateral meniscus, were included in our study (32 males and 4 females). Meniscal tears were evaluated in arthroscopy according to Dandys classification. The MRIs were retrospectively analyzed regarding the following findings: absence of bow tie sign, presence of double posterior cruciate ligament (PCL) sign, double anterior horn sign, flipped meniscus sign, disproportional posterior horn sign, and fragment within the intercondylar region. Locked types I and II fragment of medial meniscus and half-length, whole-width and whole length–half-width fragment of lateral meniscus in arthroscopy were basically correlated with fragment within the intercondylar notch and absent bow tie signs in MRI. We did not find the double PCL sign in any of the patients with a lateral meniscal bucket handle tear. The most common signs in MR images of meniscal bucket handle tears were the fragment in the notch sign and the absent bow tie sign. They were observed with equal frequency of 88.8%. The presence of double PCL sign, double anterior horn sign, flipped meniscus sign, disproportional posterior horn sign were less common (41.66, 33, 25, and 27.7%, respectively). We conclude that the presence of at least two of the six MRI signs should be regarded as highly suggestive for bucket handle tears of menisci.     

Pitfalls in MR imaging of the knee

Discrepancies between the findings of magnetic resonance (MR) imaging and those of arthroscopy were reviewed retrospectively in 52 knee examinations. Some of the discrepancies between MR imaging and arthroscopy were caused by errors in interpretation of MR images due to normal structures that mimicked meniscal tears. The transverse ligament and the lateral inferior genicular artery can produce the appearance of tears in the anterior horns of the medial and lateral menisci, respectively. The popliteus tendon may be mistaken for a tear in the posterior horn of the lateral meniscus. The normal concavity at the outer edge of the meniscus can create a volume-averaging artifact, which mimics a horizontal tear in the meniscus. Tears of the meniscus and separations of the meniscus from the joint capsule were not seen or were underestimated when the tears were oriented parallel to the plane of the image. An awareness of these pitfalls may improve the accuracy of the interpretation of MR images of the knee.     

Contribution of thin-slice (1 mm) axial proton density MR images for identification and classification of meniscal tears: correlative study with arthroscopy

Objective To evaluate the diagnostic efficacy of thin-slice (1 mm) axial proton density-weighted (PDW) MRI of the knee for meniscal tear detection and classification. Methods We prospectively assessed pre-operative MR images of 58 patients (41 males, 17 females; age range 18-62 years) with arthroscopically confirmed meniscal tear. First, we evaluated the performance of the sagittal and thin-slice axial MR images for the diagnosis of meniscal tears. Second, we compared the correlation of tear types presumed from sagittal and axial MRI with arthroscopy and tear classification from axial MRI. Tears were classified on the sagittal plane and the axial plane separately. The diagnostic performance and tear classification were compared statistically with arthroscopy results, which is accepted as the standard of reference. Results 8 of 58 patients were removed from the study group because they had complex or degenerative tears. A total of 62 tears were detected with arthroscopy in 50 patients. On the sagittal images, sensitivity and specificity values were 90.62% and 70.37%, respectively, for medial meniscus tears and 72.73% and 77.14%, respectively, for lateral meniscus tears. The corresponding values for axial images were 97.30% and 84.00%, respectively, for medial meniscus tears and 95.65% and 80.50%, respectively, for lateral meniscus tears. There was no significant difference in tear classification between the arthroscopy results and the thin-slice axial PDW MRI results (p>0.05). Conclusion thin-slice axial PDW MRI increases the sensitivity and specificity of meniscal tear detection and especially classification, which is important for surgical procedure decisions.     

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)     

Patterns of meniscal injury with acute anterior cruciate ligament tears

One hundred two patients underwent an arthrotomy for the primary repair of an acute ACL tear with or without an associated collateral ligament injury. The mean age was 23 years. Forty-seven patients (46%) had meniscal injuries. Meniscal injuries were found in 41% of Group I patients (isolated ACL injuries) and in 54% of Group II patients (injured ACL/collateral ligaments). Twenty-eight medial and 22 lateral meniscal tears were noted. Twenty-six of the 50 meniscal tears (52%) were sutured in an attempt to repair the menisci. Of these, 20 of the medial (71%), and 6 of the lateral (27%) meniscal injuries were sutured. No patients in this series required a total meniscectomy. A thorough evaluation of the menisci is mandatory in knees with an acutely injured ACL.