The clinical value of MRI in quantitative evaluation of anterior cruciate ligament mucoid degeneration / 中华放射学杂志

Objective:To explore the clinical application value of MRI in quantitative evaluation of anterior cruciate ligament mucoid degeneration (ACL-MD).Methods:From March to July 2020, 40 patients who were scheduled to undergo arthroscopic treatment were prospectively collected in the First Affiliated Hospital of Kunming Medical University.The anterior cruciate ligament tissue from the lateral edge of the tibial end was taken during the operation. Based on the pathologicalre sults, the patients were divided into the ACL-MD group ( n=19) and the normal group ( n=21). The sagittal plane three-dimensional steady-state rapid precession (3D-FIESTA), T 1 mapping, T 2 mapping, and T 2* mapping were performed before the knee joint surgery, and the scanned images were post-processed and analyzed to measure the T 1, T 2, and T 2* values of the tibial end of the anterior cruciate ligament.The relaxation time of the ACL-MD group and the normal group was compared using independent sample t test. The ROC curve was drawn using each parameter and the areas under the curve (AUC) for the diagnosis of ACL-MD were obtained.DeLong test was used to compare the differences of AUCs. Results:The T 1 [(1 291.9±273.4) ms], T 2 [(54.8±10.6) ms], and T 2* values [(30.6±6.4) ms] of anterior cruciate ligaments in the ACL-MD group were significantly higher than those in the normal group [ (1 087.0±121.0), (44.8±7.1), (20.4±4.8) ms; t=3.011, 3.473, 5.658, all P<0.001]. The AUCs of T 1, T 2, T 2* were 0.747, 0.764, 0.912, sensitivity of 63.2%, 63.2%, 100%, and the specificity of 100%, 95.2%, 76.2% in diagnosing ACL-MD. The AUC of the T 2* value was higher than those of the T 1 and T 2 values, and the differences were statistically significant ( Z=1.734, 2.162, P=0.043, 0.031). Conclusion:T 1, T 2, T 2*values measured by MRI quantitative imaging have high performance in assessing knee joint ACL-MD, and T 2* value has the largest AUC and the highest diagnostic efficiency.

Outcome of Arthroscopic Treatment of Mucoid Degeneration of the Anterior Cruciate Ligament

BACKGROUND: Mucoid degeneration of the anterior cruciate ligament is a rare pathological entity. Several authors have identified this condition, described their experiences, and suggested their own guidelines for management. The aim of this study was to detail the clinical, radiological, arthroscopic, and pathological findings of mucoid degeneration of the anterior cruciate ligament and report the clinical outcomes following arthroscopic treatment. METHODS: A historical cohort of patients who underwent arthroscopic total or partial excision of the anterior cruciate ligament due to mucoid degeneration between 2011 and 2014 were reviewed. The minimum follow-up was 3 years. Demographic, radiological, and histological findings, type of surgery, and clinical pre- and postoperative data were analyzed. The visual analogue scale score, the International Knee Documentation Committee score, and the Tegner Lysholm Knee Score were collected preoperatively, postoperatively, and during the follow-up period. RESULTS: Seventeen females (67%) and eight males (33%) were included in the final analysis. The mean age at the time of surgery was 57 years (range, 31 to 78 years). Partial resection of the anterior cruciate ligament was done in seven cases and a complete resection in 18 cases. No reconstruction was performed at the same time. A positive Lachman test and a negative pivot shift were noted after surgery in all cases. Anterior cruciate ligament reconstruction was required in only one young patient due to disabling instability. At last follow-up, the mean visual analogue scale score, International Knee Documentation Committee score, and Tegner Lysholm Knee score improved (p < 0.01). CONCLUSIONS: Our study provides further evidence that arthroscopic total or partial excision of anterior cruciate ligament is a safe and effective treatment for mucoid degeneration of the anterior cruciate ligament, improving patient satisfaction and function without causing clinical instability in daily activities. However, young patients should be forewarned about the risk of instability, and an anterior cruciate ligament reconstruction could be necessary.

Relationship between Mucoid Degeneration of the Anterior Cruciate Ligament and Posterior Tibial Slope in Patients with Total Knee Arthroplasty

PURPOSE: The purpose was to analyze the relationship between posterior tibial slope (PTS) and mucoid degeneration of the anterior cruciate ligament (ACL) in patients with total knee arthroplasty. MATERIALS AND METHODS: Four hundred and twenty-four patients (24 males and 400 females; 636 knees) who received total knee arthroplasty for osteoarthritis were included. Their mean age was 68.9 years (range, 48 to 88 years). The patients were classified into three groups according to the status of ACL; normal ACL group (group I), mucoid degeneration of ACL group (group II) and ruptured or absent ACL group (group III). Plain lateral radiographs were used to measure the PTS and the values were compared among groups. RESULTS: There were no significant differences with regard to gender, age and left-to-right side ratio among groups (p>0.05). The mean PTS was 9.9degrees (range, 0.6degrees to 20.1degrees) in group I (161 knees), 10.8degrees (range, 0.2degrees to 21.8degrees) in group II (342 knees) and 12.3degrees (range, 2degrees to 22.2degrees) in group III (133 knees), which showed significant differences (p<0.001). CONCLUSIONS: The patients with mucoid degeneration of the ACL and those with ruptured or absent ACL had greater PTS than those with normal ACL. These findings suggest that an increased PTS may be one of the causative factors for mucoid degeneration of the ACL.

Mucoid Degeneration of Both ACL and PCL

Unlike meniscal tears and chondral defects, the mucoid degeneration of the anterior cruciate ligament (ACL) is a rare cause of knee pain and there have been no case reports of mucoid degeneration of both the ACL and the posterior cruciate ligament (PCL). A 48-year-old-male patient presented with knee pain and limitation of motion. The patient's magnetic resonance imaging, arthroscopic findings, and pathologic diagnosis confirmed a clinical diagnosis of mucoid degeneration of both the ACL and the PCL. The symptoms disappeared after arthroscopic partial excision of the ACL and PCL.

Mucoid Degeneration of Anterior Cruciate Ligament: Correlation between MR Imaging and Pathologic Findings in Patients with Osteoarthritis of the Knee

PURPOSE: To evaluate the mucoid degeneration (MD) of the anterior cruciate ligament (ACL) of the knee by correlation of MRI findings with pathology, in the patients with osteoarthritis (OA). MATERIALS AND METHODS: This study included 17 patients (mean 68.8 years old) who underwent preoperative MRI. In proton density-weighted sagittal and coronal images ACLs were evaluated for the thickness and signal intensity (SI). Total knee replacement arthroplasty was performed and the pathologic findings of ACL were evaluated. MD was classified as 3 grades according to the degenerated amount in microscopy. Thickness and SI was evaluated as normal or increased on MRI. RESULTS: All of the 4 patients who showed thickened ACL showed increased SI on MRI. All of the 8 patients with increased SI of the ACL on MRI had MD in the ACL. However, remained 9 patients also had MD, in spite of their normal thickness and SI on MRI. Calcification was seen in 5 patients. CONCLUSION: Eight cases who showed ACL thickening or increased SI on MRI were well correlated with MD, however, because the other nine cases who showed normal thickness and normal SI of ACL on MRI also showed MD in pathology, normal MRI finding should not exclude the possibility of MD of ACL.