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

OBJECTIVETo explore diagnostic value of MRI on posterior root tear of medial and lateral meniscus.

METHODSFrom January 2012 to January 2016, clinical data of 43 patients with meniscal posterior root tear confirmed by arthroscopy were retrospective analyzed, including 25 males and 18 females, aged from 27 to 69 years old with an average age of(42.5±8.3)years old;27 cases on the right side and 16 cases on the left side. MRI examinations of 43 patients with tear of posterior meniscus root confirmed by knee arthroscopies were retrospectively reviewed. MRI images were double-blinded, independently, retrospectively scored by two imaging physicians. Sensitivity, specificity and accuracy of MRI diagnosis of lateral and medial meniscus posterior root tear were calculated, and knee ligament injury and meniscal dislocation were calculated.

RESULTSForty-three of 143 patients were diagnosed with meniscus posterior root tears by arthroscopy, including 19 patients with lateral tears and 24 patients with medial tears. The sensitivity, specificity and accuracy in diagnosis of posterior medial meniscus root tears for doctor A were 91.67%, 86.6% and 83.9% respectively, and for doctor B were 87.5%, 87.4% and 87.4%, 19 patients with medial meniscal protrusion and 2 patients with anterior cruciate ligament tear. The sensitivity, specificity and accuracy in diagnosis of posterior lateral meniscus root tears for doctor A were 73.7%, 79.9% and 79% respectively, and for doctor B were 78.9%, 82.3% and 82.5%, 4 patients with lateral meniscus herniation and 16 patients with cruciate ligament tear. Kappa statistics for posterior medial meniscus root tears and posterior lateral meniscus root tears were 0.84 and 0.72.

CONCLUSIONSMRI could effectively demonstrate imaging features of medial and lateral meniscal root tear and its accompanying signs. It could provide the basis for preoperative diagnosis of clinicians, and be worthy to be popularized.

Adult ; Aged ; Anterior Cruciate Ligament Injuries ; diagnostic imaging ; Arthroscopy ; Female ; Humans ; Knee Injuries ; diagnostic imaging ; Magnetic Resonance Imaging ; Male ; Menisci, Tibial ; diagnostic imaging ; Middle Aged ; Retrospective Studies ; Sensitivity and Specificity ; Tibial Meniscus Injuries ; diagnostic imaging

OBJECTIVETo evaluate the values of spiral CT arthrography with multiplanar reconstruction and virtual arthroscopy technique in diagnosis of internal derangements of the knee.

METHODSTen bovine knees were used for experiment. The menisci, anterior and posterior cruciate ligaments and cartilage of these 10 bovine knees were injured with a hook. Each of the joints was injected with 100 ml air, then soon scanned with a PQ6000 spiral computed tomography scanner. The data obtained was input into the work station, and multiplanar reconstruction technique was used to illustrate lesions in the knees. The results of CT diagnosis were compared to those found by gross inspection of the specimens. Clinically, 10 knees of 9 patients diagnosed as internal derangement were evaluated with the same method after 50-70 ml air was injected into each of the joints. Nine months later, the data of 2 patients were used for CT endoscopy reconstruction. The results were compared with intraoperative findings.

RESULTSExperimentally, the sensitivity and specificity were 88.9% and 93.9% by detection of meniscal abnormalities, 85.7% and 100% by detection of cruciate ligament lesions, and 72.7% and 100% by detection of cartilage damage, respectively. Clinically, the sensitivity and specificity were 90.0% and 95.0% by detection of meniscal lesion. As to ligament, the figures were 85.7% and 100% respectively. Images of virtual arthroscopy simulated the images of real arthroscopy.

CONCLUSIONSSpiral CT arthrography of multiplanar reconstruction technique offers fine images of internal structures of the knee, with clear border and internal structure. It is an accurate method for detecting meniscal, cruciate and collateral ligament and cartilaginous lesions that cause internal derangement of the knee. Virtual arthroscopy technique is a hopeful method for detecting reasons of derangement of the knee.

Animals ; Anterior Cruciate Ligament ; pathology ; Anterior Cruciate Ligament Injuries ; Arthroscopy ; Cattle ; Female ; Humans ; Knee Injuries ; diagnostic imaging ; pathology ; surgery ; Male ; Medial Collateral Ligament, Knee ; injuries ; pathology ; Menisci, Tibial ; pathology ; Reconstructive Surgical Procedures ; Tibial Meniscus Injuries ; Tomography, Spiral Computed

OBJECTIVE: To investigate the diagnostic value of multislice spiral CT (MSCT) and MRI in occult fracture of knee joint with meniscus and ligament injury. METHODS: From January 2020 to March 2021, 63 patients with knee occult fracture with meniscus and ligament injury, including 41 males and 22 females, aged from 21 to 67 years old, with an average of (44.35±8.77) years old, the course of disease ranged from 1 to 6 days, with an average of (4.64±1.75) days, the body mass index (BMI) was (19.85±2.78) kg/m². MSCT and MRI data of 63 patients were collected and statistically analyzed to evaluage their diagnist value. RESULTS: The detection of MRI for occult knee fravtures with meniscus and ligament injury, joint cavity effusion, bone marrow edema, and articular surface injury were 100.00% (63/63), 95.24% (60/63), 42.86% (27/63) and 36.51% (23/63), respectively. The detection rates of MSCT were 49.21% (31/63), 41.27% (26/63), 0.00% (0/63) and 1.59% (1/63), respectively, significantly lwver than that of MRI (P<0.05). The diagnostic sensitivity, specificity and accuracy of MRI were significantly higher than those of MSCT(P<0.05). CONCLUSION The sensitivity, specificity and accuracy of magnetic resonance imaging in the diagnosis of occult fracture of knee joint with meniscus and ligament injury are significantly better than that of MSCT. MRI has higher accuracy in the diagnosis of peripheral tissue diseases such as joint cavity, articular surface and bone marrow, and can reduce the risk of clinical misdiagnosis.
Male ; Female ; Humans ; Young Adult ; Adult ; Middle Aged ; Aged ; Tibial Meniscus Injuries/diagnostic imaging* ; Fractures, Closed/diagnostic imaging* ; Arthroscopy/methods* ; Knee Injuries/diagnostic imaging* ; Knee Joint/diagnostic imaging* ; Magnetic Resonance Imaging/methods* ; Ligaments ; Meniscus ; Tomography, Spiral Computed ; Fractures, Bone ; Anterior Cruciate Ligament Injuries

A 35-year-old female patient with previous left knee anterior cruciate ligament repair for a skiing injury presented six years later with a traumatic lateral patellar subluxation. Radiographs and magnetic resonance imaging of her left knee joint showed an ossific structure in the region of the lateral meniscus. This was diagnosed as a meniscal ossicle and confirmed during successful arthroscopic excision. The imaging features of meniscal ossicles are reported.
Adult ; Anterior Cruciate Ligament ; surgery ; Anterior Cruciate Ligament Injuries ; Arthroscopy ; Bone and Bones ; pathology ; Diagnostic Imaging ; methods ; Female ; Humans ; Knee Joint ; diagnostic imaging ; pathology ; Magnetic Resonance Imaging ; Menisci, Tibial ; diagnostic imaging ; pathology ; Postoperative Complications ; Radiographic Image Interpretation, Computer-Assisted ; Tibial Meniscus Injuries