OBJECTIVETo determine the mechanism of pseudo-tears of the lateral meniscus caused by the transverse geniculate ligament (TL) and the miniscofemoral ligament(MFL) and to investigate a method to differentiate pseudo-tears from true tear of the lateral meniscus.

METHODSForm June 2012 to February 2014, MR examinations of 72 knees (44 left knees and 28 right knees) without tear of the lateral meniscus verified by arthroscopy were performed in the sagittal and coronal plane. There were 41 males and 31 females in the group, with an average age of 33.7 years old (ranged from 25 to 61). The MR appearance of the TL and the MFL was carefully observed.

RESULTSThere existed fatty tissue in the gap between the TL and the anterior horn of the lateral meniscus and its central tendinous attachment. On the sagittal images, the fatty tissue formed a linear high-signal cleft between the TL and the anterior horn of the lateral meniscus. This might be mistaken as an oblique tear within the anterior horn of the lateral meniscus. It was called as pseudo-tears of the anterior horn of the lateral meniscus. In sagittal plane, the MFL was identified as a circle-like or short stick-like area of low signal intensity anterior or posterior to the posterior cruciateligament. Nevertheless, a belt-shaped area of low signal intensity from the posterior horn of the lateral meniscus to lateral facet of the medial femoral condyle was identified in the coronal plane. A linear area of high signal intensity between the MFL and the lateral meniscus was found in sagittal plane, which might be mistaken as an oblique tear within the posterior horn of the lateral meniscus. It was called pseudo-tears of the posterior horn of the lateral meniscus. The occurrence rate of the TL was 34.7% (25/72). The prevaleribe of pseudo-tears of the anterior horn of the lateral meniscus was 18 cases. The shape of the anterior horn of the lateral meniscus was regular, and the course of the pseudo-tears cleft was oblique. The occurrence rate of the MFL was 73.6% (53/72), which included the anterior MFL 23.6% (17/72), the posterior MFL 70.8% (51/72) and the two ligaments coexisted 16.7% (12/72). The prevalence of pseudo-tears of the posterior horn of the lateral meniscus was 25 cases. All observed pseudo-tears had either in posteroinferiorly oblique direction (19/25) or in vertical direction (6/25).

CONCLUSIONBased on the location and direction of pseudo-tears and observation in the continuous sagittal plane and the coronal plane, pseudo-tears is easily differentiated from the true tear of the lateral meniscus

Adult ; Female ; Humans ; Knee Injuries ; diagnostic imaging ; surgery ; Knee Joint ; diagnostic imaging ; surgery ; Magnetic Resonance Imaging ; Male ; Menisci, Tibial ; diagnostic imaging ; surgery ; Middle Aged ; Radiography ; Tibial Meniscus Injuries

BACKGROUND: The clinical and radiologic features of radial tears of the medial meniscus posterior horn were compared with those of horizontal tears. METHODS: From January 2007 to December 2008, 387 consecutive cases of medial meniscal tears were treated arthroscopically. Among these, 91 were radial tears in the medial meniscus posterior horn, and 95 were horizontal tears in the posterior segment of the medial meniscus. The patients' data (age, gender, duration of symptom, body mass index, and injury history), radiographic findings (Kellgren and Lawrence score, posterior tibial slope, and femorotibial angle), and chondral lesions were recorded. RESULTS: The patient factors of age, gender, and body mass index were related to radial tears of the medial meniscus posterior horn. Radial tears were significantly correlated with Kellgren and Lawrence score, varus alignment, posterior tibial slope, and severity of the chondral lesion. CONCLUSIONS: Radial tears of the medial meniscus posterior horn are a unique clinical entity that are associated with older age, females and obesity, and are strongly associated with an increased incidence and severity of cartilage degeneration compared to horizontal tears.
Adult ; Age Factors ; Aged ; Arthroscopy ; Body Mass Index ; Female ; Humans ; Knee Injuries/*pathology/radiography/surgery ; Male ; Menisci, Tibial/*injuries/*pathology/radiography/surgery ; Middle Aged ; Retrospective Studies ; Sex Factors

OBJECTIVE: To determine the diagnostic accuracy of CT arthrography and virtual arthroscopy in the diagnosis of anterior cruciate ligament and meniscus pathology. MATERIALS AND METHODS: Thirty-eight consecutive patients who underwent CT arthrography and arthroscopy of the knee were included in this study. The ages of the patients ranged from 19 to 52 years and all of the patients were male. Sagittal, coronal, transverse and oblique coronal multiplanar reconstruction images were reformatted from CT arthrography. Virtual arthroscopy was performed from 6 standard views using a volume rendering technique. Three radiologists analyzed the MPR images and two orthopedic surgeons analyzed the virtual arthroscopic images. RESULTS: The sensitivity and specificity of CT arthrography for the diagnosis of anterior cruciate ligament abnormalities were 87.5%-100% and 93.3-96.7%, respectively, and those for meniscus abnormalities were 91.7%-100% and 98.1%, respectively. The sensitivity and specificity of virtual arthroscopy for the diagnosis of anterior cruciate ligament abnormalities were 87.5% and 83.3-90%, respectively, and those for meniscus abnormalities were 83.3%-87.5% and 96.1-98.1%, respectively. CONCLUSION: CT arthrography and virtual arthroscopy showed good diagnostic accuracy for anterior cruciate ligament and meniscal abnormalities.
Adult ; Anterior Cruciate Ligament/injuries/*radiography ; Arthrography/*methods ; Arthroscopy/*methods ; Diagnosis, Computer-Assisted/methods ; Human ; Knee Injuries/*diagnosis/radiography ; Male ; Menisci, Tibial/injuries/*radiography ; Middle Aged ; Sensitivity and Specificity ; Tomography, X-Ray Computed/methods

Authors analyzed the findings of nineteen cases of arthroscopic second-look operations after posterior cruciate ligament (PCL) reconstruction with autogenous bone-patellar tendon-bone (BPTB) and Trevira augmentation by two tunnel technique during the period from Nov, 1993 to Jan. l997 in fifty-one cases, along with the results of reconstruction in terms of clinica1 knee scoring, radiographichl and arthroscopic findings. The results were as follows; Age ranged fmm 20 to 53 years, the average being 32.3 years. Thirteen cases (68%) had associated knee injuries; five medial collateral ligament (MCL) injuries, four lateral collateral ligament (LCL) injuries, two associated injuries of MCL and medial meniscus, one both menisci and one associated injury of anterior cruciate ligament and MCL. The average period fmm PCL injury to reconstruction was 7 weeks (range, 1 to 52 wecks) and the mean period from PCL reconstruction to second-look operation was 20.3 months (range, 10 to 46 months). The average Miiller s knee score at the last follow-up was 86 paints. The radiographical results: The distance of posterior translation of the PCL reconstrueted knee compared with the normal sidc knee in posterior stress roentgenography was average 3.8mm (range, 0 to 1 1 mm). The position of the fernoral bone block on the plane of extended Blumansaats line, from the anterior end of the line, was average 32%. The level of proximal end of the tibial bone block according to the tibial tunnel orifice into the joint was mean negative 2.6 degrees position. The findings of arthroscopic second-look examination; In 9 cases (47%), the reconstructed ligamcnts were well covered with synovial tissue and looked like almost normal PCL. There were five cases (26%) of severe fragmentation, three cases (16%) of partial torn fibers of the grafted tendon. And one case showed the thinning of thc grafted tendon compared with the initial diameter at the time of reconstruction and one case showed overgrawth of the synovial membrane which suitounding the grafted tendon. All the Trevira which were augmented at the time of PCL reconstruction were ruptured. Twelve cases (63%) were stable, three cases (16%) were slightly lax and 4 cases (21%) showed laxity of the grafted tendon by the posterior drawer test and probing under arthroscopy, The isometricity which was checked at the time of PCL reconstruction was average 3.4mm. From the ahove results, PCL reconstruction with autogenous BPTB by the two tunnel technique seemed to be a valuable procedure, but there were some cases of unfavorable results. Authors think that a new graft fixation method is needed for resolving the problem mentioned above.
Anterior Cruciate Ligament ; Arthroscopy ; Collateral Ligaments ; Dronabinol ; Follow-Up Studies ; Joints ; Knee ; Knee Injuries ; Lateral Ligament, Ankle ; Menisci, Tibial ; Paint ; Posterior Cruciate Ligament* ; Radiography ; Synovial Membrane ; Tendons ; Transplants