Anterior Cruciate Ligament Mucoid Research Articles

Ancillary findings in distinguishing between anterior cruciate ligament mucoid degeneration and sprain on MRI: a practical approach.

Imaging findings of both anterior cruciate ligament (ACL) sprain and mucoid degeneration overlap in some cases, which may cause errors in magnetic resonance imaging (MRI) evaluation. To determine the ancillary findings on MRI in distinguishing between ACL sprain and mucoid degeneration, and also to obtain a diagnostic scheme. MRI scans of 77 patients with ACL mucoid degeneration and 77 cases with ACL sprain were retrospectively evaluated to compare with regard to parameters of age, sex, side, the status of posterior cruciate ligament - medial collateral ligament - lateral collateral ligament, bone marrow edema, intraosseous cyst, subchondral sclerosis, chondromalacia, meniscus tear, effusion, and osteochondral body. A decision tree algorithm was created to predict pathology in ACL, whether it was a sprain or mucoid degeneration. The prevalence of female sex, femoral intraosseous cyst, tibial intraosseous cyst, subchondral sclerosis, femoral chondromalacia, tibial chondromalacia, medial meniscus tear, and lateral meniscus tear were significantly higher in the ACL mucoid degeneration group (P < 0.001, P = 0.016, P < 0.001, P = 0.003, P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively). The probability of being mucoid degeneration increased 41.2 times (95% confidence interval [CI] = 5.296-321.132) in cases with tibial intraosseous cyst and increased 1.05 times (95% CI = 1.010-1.080) with each one-year increase in age (P < 0.001 and P = 0.011, respectively). The decision tree algorithm had an overall accuracy of 79.2%. Ancillary findings are helpful in the diagnosis of suspicious cases for ACL mucoid degeneration and ACL sprain. The decision tree algorithm offers a practical and successful approach to this issue.

Management of hypertrophic anterior cruciate ligament mucoid degeneration by arthroscopy

Introduction: Mucoid degeneration of the anterior cruciate ligament (ACL) is a less common entity. The primary pathology is the damage to the functional synovial lining protecting the ACL with no significant preceding trauma. Two types are described i.e., cystic (synovial and mucoid cysts) and infiltrating (mucoid degeneration). These lesions can be asymptomatic. When symptomatic, the patient complained of posterior knee pain with restriction of flexion in the knee. The diagnosis is confirmed by Magnetic Resonance Imaging of the Knee. Recent trends include arthroscopic procedures, including ACL debridement, i.e. partial resection. Total resection can be required in a few cases with ACL reconstruction. Inclusion Criteria: Diagnosed cases of ACL mucoid degeneration on MRI. Exclusion Criteria: Post-traumatic knee injuries-meniscal or ligamentous or bony, ACL synovial or mucoid cysts. Materials and Methods: A total of 18 patients diagnosed with ACL mucoid degeneration were included in the study. The study was conducted from August 2019-August 2021. The patients were assessed clinically with history and clinical examination. MRI was advised in patients with clinical suspicion of ACL mucoid degeneration. Results: The study sample consisted of 18 patients (7 females and 11 males) with ages ranging from 30 to 55 years (mean age, 43.2 years) in males and 35 to 55 years (mean age, 41.5 years) in females. On clinical assessment, exacerbation of pain was more commonly related with terminal flexion in 10 patients (58.8%) as compared to terminal extension (7 patients, 41%). No motion-related exacerbation of pain was seen in 1 case. 17 patients had an extension deficit. No complaint of instability was seen except for 2 cases. Postoperatively an average improvement of the Visual analogue scale by 4 was seen. No flexion or extension deformity was noted. No patient had any major complication. On follow up Anterior Lachman test was grade 1 in 16 cases and in others it was same as opposite non-affected knee. A complete resection of ACL with reconstruction using hamstring graft was done in 1 patient. The same patient showed a pain improvement of 4 scales on VAS. The patient however had episodes of instability. Conclusion: A clinical suspicion of mucoid degeneration of ACL with confirmatory classical appearance on MRI are key to diagnosis. Symptomatic pain relief is better provided with ACL debridement with mild laxity in upcoming future.

Role of ultrasound-guided decompression in management of mucoid degeneration of the anterior cruciate ligament.

To assess the effectiveness of ultrasound-guided decompression in managing symptomatic mucoid degeneration of the anterior cruciate ligament (ACL). Retrospective analysis of 55 patients who underwent ultrasound-guided ACL mucoid degeneration decompression between July 2013 and August 2019. Subjective satisfaction scores were gathered immediately post-procedure for all 55 patients; follow-up satisfaction scores (scale of 0-10, 10 being excellent) were gathered telephonically for 46 patients (83.6%) up to 63months post-procedure. Follow-up duration of each patient was classified as short (1-6months), intermediate (7-12months), or long (more than 12months) post-procedure. Forty-five patients (81.8%) MRI were retrospectively analyzed and classified into cystic (n = 13, 28.9%), mucoid (n = 11, 24.4%), or mucoid-cystic (21, 46.7%) types. Multivariate logistic regression was used to identify associations between follow-up satisfaction score, follow-up duration, patient age, and type of ACL degeneration. All patients had immediate marked post-procedure improvement, with excellent (>7/10) satisfaction scores. Forty-six of 55 patients were telephonically followed up: 21 (45.6%) short-term interval, 18 (39.1%) intermediate term, and 7 (15.2%) long-term. Thirty (65.22%) patients had excellent and eight (17.4%) patients had average satisfaction scores at follow-up. Eight (17.4%) patients had poor post-procedure satisfaction scores within six months. There were no significant associations between immediate or follow-up satisfaction score and duration of follow-up, age of patient, or type of ACL degeneration. Ultrasound-guided aspiration, fenestration, and injection are an effective, safe, minimally invasive and radiation-free technique for management of mucoid degeneration of ACL with excellent immediate- and long-term results.

A Retrospective Comparison of ACL Tear and Mucoid Degeneration MRI Findings and an Emphasis on Evaluating of ACL, Blumensaat, and PCL Angles.

Objective:To determine MRI findings that can differentiate anterior cruciate ligament (ACL) tears from mucoid degeneration.Material and Methods:Thirty-seven patients with complete ACL tears and 43 with ACL mucoid degeneration were included in this study. Discontinuity, the abnormal signal intensity of the ACL on fat-saturated-PD weighted images, contusions, a deep lateral femoral notch, anterior tibial translation, uncovered posterior horn of the lateral meniscus, a celery stalk appearance, thickening, ganglion cysts, intraosseous cysts, the ACL, Blumensaat, and posterior cruciate ligament (PCL) angles were evaluated. Optimum threshold values, sensitivity, specificity, and 95% CIs for the angles were calculated to predict the tear.Results:The prevalence of the significant findings in a tear versus mucoid degeneration, respectively, was as follows: discontinuity (97% vs. 0%, p < 0.001), contusions (65% vs. 2%, p < 0.001), the deep lateral femoral notch (22% vs. 0%, p = 0.001), anterior tibial translation (70% vs. 14%, p < 0.001), uncovered the lateral meniscus (46% vs. 7%, p < 0.001), a celery stalk appearance (0% vs. 66%, p < 0.001), thickening (19% vs. 100%, p < 0.001), ganglion cysts (14% vs. 70%, p < 0.001), and intraosseous cysts (8% vs. 63%, p < 0.001). Threshold values of ACL, Blumensaat, and PCL angles to predict the tear were ≤36° (78% sensitivity, 91% specificity), >11° (84%, 81%), and ≤96° (65%, 91%), respectively.Conclusion:A celery stalk appearance in the mucoid degeneration and discontinuity in an ACL tear are important in the differential diagnosis. ACL, Blumensaat, and PCL angles can be helpful in settings of diagnostic uncertainty.

Mucoid degenerated anterior cruciate ligament (ACL) managed by arthroscopic ACL reconstruction: A case series

Introduction: Mucoid degeneration of the Anterior Cruciate Ligament is a rare degenerative condition affecting the middle age population (16 to 50 years). The infiltration of glycosaminoglycan into the substance of the ACL causes the ligament to swell up and impinge on the intercondylar notch and Posterior Cruciate Ligament. This results in posterior knee pain and restriction of terminal movements. The current trend of management is debulking the ligament by stripping the degenerated part and preserving the native thin ACL. This poses two problems - 1. Difficulty in identifying the degenerated parts by the arthroscope. Stripping is done with the aid of pre-op MRI; 2. Chances of under stripping (recurrence of the symptoms) or over stripping (laxity and ACL failure). Studies have shown high incidence of grade 1/grade 2 laxity by Lachman test 6 months post-op and a requirement of Secondary ACL reconstruction in many patients. Goal: The goal of this study is to assess the functional outcome of Primary ACL reconstruction with autologous quadrupled hamstring tendon graft after complete excision of the native degenerated ACL. Materials and Methods: This is a prospective study of 13 patient (7 male, 6 female) of average age 41 (25-63) years presenting with posterior knee pain and restriction of flexion for an average period of 6 months (15 days – 36 months) diagnosed with Mucoid degeneration of ACL by MRI, arthroscopy and by histo-pathological examination. They were operated by ACL reconstruction following complete excision of degenerated ACL, as a single stage procedure. Evaluation: The patients were evaluated both pre-operatively and post-operatively by Lysholm knee scoring system and VAS (visual analog score) pain scoring system. Results: Postoperatively, patients were followed up for a minimum of 1 year (average of 14.9 months). There was no evidence of recurrence or instability at the end of follow-up. There was significant improvement in Lysholm score (34.6 to 83.2) and VAS (5.76 to 0.54). Conclusion: Treatment of ACL mucoid degeneration by this modality is effective in preventing recurrence, post-operative laxity and provides better functional outcome compared to the classical partial resection of the degenerated ACL.

Association of Mucoid Degeneration of the Anterior Cruciate Ligament at MR Imaging with Medial Tibiofemoral Osteoarthritis Progression at Radiography: Data from the Osteoarthritis Initiative.

Purpose To determine whether anterior cruciate ligament (ACL) mucoid degeneration in participants with or at risk for osteoarthritis is associated with longitudinal risk of radiographic progression of medial tibiofemoral compartment joint space loss (JSL). Materials and Methods Baseline demographic, clinical, radiographic, and Magnetic Resonance (MR) Imaging Osteoarthritis Knee Score (MOAKS) data were evaluated in 600 participants from the Osteoarthritis Initiative database. Two blinded musculoskeletal radiologists independently evaluated baseline MR images for ACL mucoid degeneration. Multiple logistic regression was used to investigate the association between ACL mucoid degeneration at MR imaging and JSL progression at radiography, defined as a minimum joint space width decrease greater than 0.7 mm (48 months; cutoff according to mean and standard deviation of 1-year minimum joint space width changes in 90 knees of reference group). Stratified analysis was performed based on baseline cartilage surface damage. Results Knees with ACL mucoid degeneration showed a greater proportion of JSL progression compared with knees with a normal ACL (64% vs 47%; P = .004). After adjustment for all demographic, clinical, radiographic, and MOAKS variables, ACL mucoid degeneration was not statistically significantly associated with JSL progression in the entire cohort (adjusted odds ratio, 1.66; 95% confidence interval: 1.00, 2.77; P = .051). In subgroup analysis, ACL mucoid degeneration was statistically significantly associated with JSL progression in participants with less baseline cartilage surface damage (maximum cartilage surface loss of ≤75% in all subregions [P = .015] and ≤4 of involved subregions with cartilage surface loss [P = .028]). Conclusion ACL mucoid degeneration in participants with or at risk for osteoarthritis is associated with progression of medial tibiofemoral compartment JSL in knees with less baseline cartilage surface area damage. © RSNA, 2018 Online supplemental material is available for this article.

Anterior Cruciate Ligament Ganglion Cyst and Mucoid Degeneration: A Review.

Mucoid degeneration and ganglion cyst are two distinct non-traumatic lesions of the anterior cruciate ligament (ACL) that most commonly occur discretely but occasionally coexist. They are relatively uncommon, and their exact aetiopathogenesis is still not clear. ACL ganglion cyst occurs more frequently among relatively younger patients compared to mucoid degeneration. They could be asymptomatic and discovered incidentally while evaluating the knee for other pathologies. Symptomatic cases of the two conditions present with nonspecific chronic pain, painful limitation of terminal flexion and extension, and mechanical block (among other symptoms), similar to that of other internal derangement pathologies of the knee. Magnetic resonance imaging is the investigation of choice, and diagnostic criteria are defined. Arthroscopic management of these conditions efficiently provides an improvement in symptoms without instability. Computed tomography scan guided aspiration is also useful in selected cases of ACL ganglion cyst. ACL ganglion cyst and mucoid degeneration should be considered in the differential diagnosis of chronic knee pain and stiffness of unspecified etiology.

Association of mucoid degeneration of anterior cruciate ligament with knee meniscal and cartilage damage

To assess the prevalence of anterior cruciate ligament (ACL) mucoid degeneration in patients referred for routine knee magnetic resonance (MR) imaging, and its association with age and structural joint damage. Four independent radiologists assessed 413 consecutive knee MR examinations for the presence of a normal or ruptured ACL, or ACL mucoid degeneration. Knees with ACL mucoid degeneration were frequency matched by age, sex, and MR field strength with consecutive control knees with a normal ACL (1:2 ratio). Differences in meniscal and cartilage damage of the tibiofemoral compartments, as determined by the Whole-Organ MR Imaging Score (WORMS) system, were compared by Mann-Whitney U tests. Multivariable logistic regression analysis identified the association of ACL mucoid degeneration with severe MTFC cartilage damage (WORMS≥5). Patients with ACL mucoid degeneration (n = 36; 36% males; median age 55.5 years, range: 26-81) were older than patients with a normal (P < 0.001) or ruptured ACL (P < 0.001), without sex predilection (P = 0.76), and were more frequently diagnosed at 3 T (12%) compared to 1.5 T (2%). Knees with ACL mucoid degeneration had statistically significantly more medial meniscal (P < 0.001) and central and posterior medial tibiofemoral compartment (MTFC) cartilage (P < 0.001) damage compared with control knees (n = 72), but there were no differences in patients ≤50 years (P = 0.09 and 0.32, respectively). In multivariable logistic regression, severe MTFC cartilage damage (WORMS≥5) was significantly associated with ACL mucoid degeneration (odds ratio 4.09, 95% confidence interval 1.29-12.94, P = 0.016). There is a strong association between ACL mucoid degeneration and cartilage damage in the central and posterior MTFC, especially in patients >50 years.

Radiological evidence for the triple bundle anterior cruciate ligament.

The anterior cruciate ligament (ACL) has traditionally been described as having two bundles--one anteromedial and one posterolateral. This has been challenged by studies proposing the existence of a third, intermediate, bundle with distinct functional significance, an arrangement that has been described in a number of domesticated animal species. No radiological evidence for the triple bundle ACL has previously been described. A prevalence study was carried out on 73 consecutive human knee magnetic resonance (MR) studies to determine the number of visible bundles, excluding individuals with a history of ACL injury or mucoid degeneration. A triple bundle ACL was demonstrated in 15 out of 73 human knees (20.5%, 95% confidence interval 12.9-31.2%). This is the first radiological description of the human triple bundle ACL. There was MR imaging evidence of a triple bundle ACL in approximately one fifth of human knees in this study.

Reduction plasty for hypertrophic anterior cruciate ligament mucoid degeneration: Clinical and knee laxity outcomes in 23 cases

The best treatment for anterior cruciate ligament (ACL) mucoid degeneration remains open to debate. Current options are total or partial ACL resection, or a more conservative strategy, reduction plasty. The goal of this study was to retrospectively evaluate the effects of reduction plasty for ACL hypertrophy due to mucoid degeneration from clinical outcome and knee laxity points of view. Arthroscopy was carried out on 23 knees (21 patients) to perform a circular volume reduction plasty of the ACL, while preserving the greatest number of ligament fibers. Notchplasty was not performed. All the patients were seen again with an average follow-up of 32 months (range 8-70). All the knees except three had symmetric postoperative flexion. Three patients still had pain. No patient reported having subjective feelings of instability. Among the 20 knees tested with the GNRB(TM) knee laxity measurement device, one knee had a 2.4mm difference in laxity and three had between 3 and 4mm of difference; 16 knees had no residual laxity. Treatment of ACL mucoid degeneration by reduction plasty leads to complete pain relief in 80% of cases while maintaining good postoperative knee stability. Level IV. Retrospective study.

Tram-Track Appearance of the Posterior Cruciate Ligament (PCL): Correlations With Mucoid Degeneration, Ligamentous Stability, and Differentiation From PCL Tears

The purpose of our study was to describe the MRI findings in the posterior cruciate ligament (PCL) analogous to mucoid degeneration in the anterior cruciate ligament (ACL); to correlate MRI findings in the PCL with ligamentous stability; to differentiate the PCL tram-track appearance from the appearance of PCL tears; and to emphasize the coexistence of PCL and ACL mucoid degeneration, cruciate ganglia, and meniscal cysts. The tram-track PCL appearance commonly coexists with ACL mucoid degeneration; ganglia; and, less frequently, meniscal cysts. Both PCL tears and MRI findings suggestive of PCL mucoid degeneration show ligament thickening and increased PCL signal intensity. Tram-track PCLs are usually asymptomatic and typically have no ligamentous instability.

Anterior cruciate ligament mucoid degeneration: a review of the literature and management guidelines

Anterior cruciate ligament (ACL) mucoid degeneration is a rare encounter in clinical practice, different, but often confused with ACL mucoid cysts. Its pathophysiology remains unclear. However, recent publications have suggested that it might be underdiagnosed or misdiagnosed, and that the adverse effects of treatment by ACL resection might be underestimated. The object of this work was to summarize this scattered knowledge to improve patient management. The authors carried out an exhaustive and comprehensive review of up-to-date literature. An extensive search of the MEDLINE database was carried out using MESH terms (ganglion cyst, anterior cruciate ligament) and generic search terms (mucoid degeneration, hypertrophy). Anterior cruciate ligament mucoid degeneration is determined by interstitial glycosaminoglycan deposits amidst the collagen bundles causing ACL hypertrophy, knee pain, and limited range of motion. It is thought to arise from a primary synovial lesion and is associated with arthritic change or subsequent to acute or repeated trauma. Diagnosis is made on MRI scans and confirmed on histopathological samples. Current treatment involving ACL arthroscopic resection is efficient on pain and range of motion but is not a benign procedure and causes knee laxity. Anterior cruciate ligament mucoid degeneration needs to be more broadly known and properly diagnosed so that progress can be made in its management. Further research will be necessary to confirm the current trends in the literature, which suggest being less aggressive with ACL arthroscopic resection when dealing with mucoid degeneration and making more use of conservative measures such as notchplasty. Systematic review, Level IV.

Anterior cruciate ligament mucoid degeneration: Selecting the best treatment option

Mucoid degeneration of the anterior cruciate ligament (ACL) is a little-known entity. The clinical presentation is one of posterior pain with limited flexion. Its interstitial nature within the ACL structure contrasts with synovial cyst of the ACL. Arthroscopic treatment may include ACL resection, which raises the questions about the harmlessness of this procedure and the risk of anterior instability. Arthroscopic resection of ACL mucoid degeneration is effective for treating pain and flexion limitation, but at the expense of anterior laxity. This bicentric, retrospective cohort study with an average follow-up of 6years involved 27 patients (29 knees) presenting with symptomatic ACL mucoid degeneration validated by magnetic resonance imaging (MRI). Noninfiltrating synovial cysts of the ACL were excluded. Average patient age was 49 (22 to 68) years. Preoperative assessment included a questionnaire, clinical examination (Lachman and pivot shift tests), MRI and standard radiography. Arthroscopic examination analyzed the ACL aspect and its associated lesions (meniscus, cartilage). Anatomopathology samples were collected in 18 cases. Postoperative follow-up included standard radiography and dynamic examination, measuring laxity with a Telos device. Pain was posterior in 23 knees (80%). Fourteen knees (48%) had limited flexion, on average 97 degrees. Twelve partial and 17 total resections were performed. Twenty knees (69%) had associated cartilaginous lesions and 19 (66%) had meniscal lesions. Meniscectomy was undertaken in 11 cases (41%). Posterior pain disappeared in 27 cases (93%), on average 3.7 weeks after the procedure. Average improvement in flexion was 21.5 degrees (0 to 60 degrees). Twenty-eight knees (97%) showed soft and/or delayed stops on postoperative Lachman testing. Average postoperative differential laxity on the Telos device was 8.3 mm (5 to 13 mm). Average postoperative International Knee Documentation Committee (IKDC) and Knee Injury and Osteoarthritis Outcome Scores (KOOS) were 71.2 (42.5 to 92.0) and 78.2 (26.4 to 99). Two patients uderwent secondary ligamentoplasty. Treatment of ACL mucoid degeneration by arthroscopic resection is effective for posterior pain and flexion limitation. It results in postoperative laxity, but rarely in frank instability. Therefore, indications for ACL resection must be carefully selected. Young and active patients should be warned about the risk of requiring secondary ligamentoplasty. IV (retrospective cohort study).