Symptomatic ganglion cyst within the substance of the anterior cruciate ligament

Comparing MRI and arthroscopic appearances of common knee pathologies: A pictorial review

Knee pathology, including anterior cruciate ligament (ACL) tears, meniscal tears, articular cartilage lesions, and intra-articular masses or cysts are common clinical entities treated by orthopedic surgeons with arthroscopic surgery. Preoperatively, magnetic resonance imaging (MRI) is now standard in confirming knee pathology, particularly detecting pathology less evident with history and physical examination alone. The radiologist's MRI interpretation becomes essential in evaluating intra-articular knee structures. Typically, the radiologist that interprets the MRI does not have the opportunity to view the same pathology arthroscopically. Thus, the purpose of this article is to illustratively reconcile what the orthopedic surgeon sees arthroscopically with what the radiologist sees on magnetic resonance imaging when viewing the same pathology. Correlating virtual and actual images can help better understand pathology, resulting in more accurate MRI interpretations. In this article, we present and review a series of MR and correlating arthroscopic images of ACL tears, meniscal tears, chondral lesions, and intra-articular masses and cysts. Short teaching points are included to highlight the importance of radiological signs and pathological MRI appearance with significant clinical and arthroscopic findings.

Anterior cruciate ligament cysts: About a rare condition

The purpose of this study was to provide information on cysts of the anterior cruciate ligament (ACL) of the knee. This included an anatomical and radio-anatomical reminder of the cruciate ligaments of the knee, along with details of the epidemiology, etiopathogenesis, anatomical risk factors, clinical presentation, differential diagnosis, and treatment of ACL cysts. A retrospective analysis was conducted, involving the review of 7 radioclinical records from the medical imaging department of Ibn Sina University Hospital in Rabat, covering a period of 3 years (2018-2020), during which 7 cases of ACL cysts were diagnosed. The results revealed that ACL cysts are a rare condition, frequently detected incidentally during the assessment of meniscal lesions. Symptoms commonly include knee pain and limited mobility, and MRI is considered the diagnostic modality of for distinguishing between simple fluid-filled cysts and infiltrative cysts, as well as for ruling out other differential diagnoses. Treatment options include radio-guided infiltration puncture and arthroscopic resection.

An evidence-based etiology study of synovial cyst of knee cruciate ligament: a real or pseudo-cyst

PURPOSE

Synovial cyst of knee cruciate ligament (SCKCL) is a rare condition but can cause severe knee pain. The understanding of its etiology is relatively poor. This current study aimed to elucidate the pathogenesis of SCKCL based on a series of histo- and cytopathological examination.

METHODS

Ten SCKCL patients who underwent arthroscopy were enrolled, among five patients claimed past knee injury. Hematoxylin & eosin staining was conducted to the cyst wall tissue sections and Papanicolaou staining to the cyst fluid smear. Prussian blue staining was employed to both the wall section and fluid smear. Immumohistochemical staining for mesothelial cells (MC), epithelial cells (CK), vascular endothelial cells (CD31), monocytes (CD68), and hematogenous stem cells (CD117) were taken to elucidate the possible involvement of various cell types in the development of SCKCL.

RESULTS

No erythrocyte was discovered in the fluid; however, Prussian blue stained hemosiderin particles were found in the cyst wall and fluid, suggesting past hemorrhage in all patients. Abundant lymphocytes and plasmocytes were observed in the cyst wall and fluid. In addition, the cyst lining was infiltrated with abundant CD68(+) monocytes while only few MC(+) mesothelial cells were sporadically observed in four samples. The cyst submucosa was also diffused with abundant CD68(+) monocytes and proliferated capillaries stained with CD31. CD117-positve hematogenous stem cells were sporadically observed in eight specimens.

CONCLUSION

Our findings provided evidence that SCKCL is not a mature synovial cyst but rather an inflammatory pseudo-cyst. It may have resulted from past minor hemorrhage and intra-ligament chronic inflammation.

Anterior cruciate ligament reconstruction tunnel size: causes of tunnel enlargement and implications for single versus two-stage revision reconstruction

Anterior cruciate ligament (ACL) reconstructions have increased over the past 25 years. The increased incidence of ACL reconstructions has translated into a larger number of graft failures and revision ACL procedures. It is important to understand the causes of graft failure when evaluating for a revision ACL reconstruction and to appreciate changes in tunnel anatomy over time prior to planning revision surgery. In this manuscript, tunnel size for ACL reconstruction and implications for single-stage versus two-stage revision ACL reconstruction will be discussed, as well as causes of tunnel enlargement, including mechanical and biological factors.

Report of ganglion cyst in the anterior cruciate ligament of a 6-year-old child

BACKGROUND

Intra-articular ganglion cysts of the knee are extremely rare within the pediatric population. To our knowledge, only seven case reports have been published in the medical literature identifying pediatric patients with intra-articular cysts of the anterior cruciate ligament (ACL). Intra-articular cysts of the knee are a rare cause of knee discomfort and mechanical symptoms such as locking of the knee. To our knowledge, up until now the youngest patient reported in the medical literature with an intra-articular ganglion cyst of the ACL was a 7-year-old boy.

CASE REPORT

We describe a 6-year-old boy who presented with a unilateral intra-articular ganglion cyst of the ACL in the right knee. In addition to the diagnostic work-up of radiographs and MRI, the cyst was successfully treated with arthroscopic resection and debridement to decompress the cyst.

CLINICAL RELEVANCE

We provide a review of the proposed pathogenesis, diagnostic modalities, differential diagnosis, treatment options, and complications of treatment for intra-articular cysts of the ACL.

LEVEL OF EVIDENCE

Level V, case report.

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

PURPOSE

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.

METHODS

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).

RESULTS

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.

CONCLUSIONS

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.

LEVEL OF EVIDENCE

Systematic review, Level IV.

Bilateral ganglion cysts of the cruciate ligaments: a case report

Symptomatic ganglion cysts of the cruciate ligaments are rare, and bilateral cases are extremely rare, with only one reported case in the literature. We report a case of bilateral cruciate ligament ganglion cysts successfully treated with arthroscopic resection, and review the literature regarding aetiology, diagnosis and management.

Rejection reaction to stabilizing bolts after ACL reconstruction: a case report

A case of an adverse reaction to the stabilizing bolts after an ACL reconstruction is presented. A 21-year-old patient had an ACL reconstruction using the Mark II system. Six months post op, he presented to clinic having formed a pretibial swelling with serous discharge. There was mild tenderness over the femoral scar. Successive cultures of the tibial cyst effluent showed no microorganism growth and laboratory tests were normal. One year post op, symptoms and swelling persisted. X-rays showed periosteal reaction around the femoral bolt and resorption with widening of the distal tibial tunnel. An adverse reaction to the bolts was suggested as the possible cause. Surgical exploration was then performed. During the operation, free fluid evacuated from the femoral site and the tibial cyst was completely excised. All specimens were sent for culture, which were proven negative. Tibial and femoral bolts were both removed and no communication of the osseous tunnels to the joint was found. An arthroscopy was performed at the same time which showed degeneration of the ACL autograft, but an otherwise normal joint. Eighteen months later, the patient was symptom free and all inflammation indices still within the normal range.

Intra-articular ganglia of the knee joint associated with the anterior cruciate ligament: a report of 4 cases in 3 patients

Intra-articular ganglia are rare and mostly incidental findings on magnetic resonance imaging (MRI) and arthroscopy. We present 4 cases of intra-articular ganglion cysts associated with the anterior cruciate ligament (ACL) in 3 patients. The most commonly occurring symptoms were pain aggravated after stressing activities and limited knee range of motion. In 1 patient, ganglion cysts appeared in both knees with a time difference of 1 year. An MRI revealed typical signs of ganglion cysts in the substance of the ACL. Arthroscopy was performed for further evaluation and treatment. Histologic examination of the tissue removed revealed the presence of features consistent with ganglion cysts. Therefore, in the case of chronic knee discomfort with nonspecific clinical signs and symptoms and without a clear cause, an intra-articular ganglion cyst should be considered as causing pathology. An MRI is the most sensitive and specific method for diagnosis. However, the relatively slow progression of symptoms may delay the patient's decision to seek medical attention. Delayed diagnosis makes arthroscopic total resection of the ganglion technically demanding or not possible at all, and extensive debridement of the ACL may be required.

Large extrasynovial intracapsular ganglia of the knee: a report of 3 cases

PURPOSE

Intra-articular ganglia of the knee are rare and usually incidental findings of little clinical significance. Nevertheless some are large, symptomatic, and require treatment. We report on 3 patients with an intra-articular knee ganglion and an extrasynovial extension that was contained within the joint capsule. This seems to be a rare condition; a review of the English-language literature revealed no reports of similar cases.

TYPE OF STUDY

Case series.

METHODS

Three patients, 1 man and 2 women aged 27 to 40 years, presented with an almost identical history of anterior knee pain that had been treated conservatively for a long time as chondromalacia patellae. The symptoms, which were ill-defined, appeared to be deteriorating until a localized swelling appeared on the lateral side of the patella tendon in each case. On examination, a lateral meniscal cyst associated with an underlying meniscal tear was suspected. However, magnetic resonance imaging revealed a ganglion arising from the substance of the anterior cruciate ligament (case 1) and from the area of the tibial insertion of the anterior cruciate ligament (cases 2 and 3). All 3 ganglia extended anteriorly and then laterally over and in front of the lateral meniscus. The ganglia were approached through an anterior midline incision and lateral parapatellar arthrotomy, which allowed direct and easy access for complete excision. Histologic examination confirmed the diagnosis of a ganglion in all 3 cases.

RESULTS

The postoperative course was uneventful in all patients with no signs of recurrence at 1 year (case 1), 2 years (case 2), and 3 years (case 3).

CONCLUSIONS

Although the described condition seems very rare, we believe that it should be included in the differential diagnosis of cystic lesions about the knee joint.

LEVEL OF EVIDENCE

Level IV, case series, no, or historical control group.

A systematic approach to magnetic resonance imaging interpretation of sports medicine injuries of the knee

Magnetic resonance imaging is performed more commonly on the knee than on any other joint, and it is an excellent diagnostic tool that can aid in the evaluation of a host of sports-related injuries involving the ligaments, tendons, menisci, osseous structures, and articular surfaces. A thorough evaluation of the images, however, can be a daunting task, as the study often contains dozens of images obtained with multiple pulse sequences and in several imaging planes. A systematic approach will facilitate an accurate and timely evaluation of this complex examination and will ensure that all of the clinically relevant structures are adequately assessed. This article will provide a systematic approach to the interpretation of a magnetic resonance examination of the knee. The normal imaging appearance of each anatomical structure will be described, and the optimal pulse sequence and imaging plane for the evaluation of each structure will be discussed. Finally, the signs of injury will be described and illustrated.

Mucoid degeneration of the anterior cruciate ligament — a report of two cases

We report two cases of mucoid degeneration of the anterior cruciate ligament (ACL). Mucoid degeneration of the ACL is a very rare cause of knee pain. There have been only seven reported cases of mucoid degeneration of the ACL in the English literature. We reviewed previous reports and summarized clinical features and symptoms, including those found in our two cases. MRI is the most useful tool for differentiating mucoid degeneration of the ACL from an intraligamentous ganglion or other lesions in the knee joint. If this disease is considered preoperatively, it can be diagnosed easily based on characteristic findings.

Intra-articular ganglia arising from the posterior joint capsule of the knee

Magnetic resonance imaging (MRI) is an effective method to evaluate cystic lesions of the knee. Intra-articular ganglia of the knee joint was considered to be rare before the advent of MRI. However, because an MRI is often used to diagnose knee pathology, the reported prevalence of intra-articular ganglia has increased. We describe two cases of an intra-articular ganglion arising from the posterior joint capsule. Both cysts appeared to be arising from the posterior cruciate ligament by both MRI as well as arthroscopy through a lateral infrapatellar portal. However, arthroscopy through a posteromedial portal revealed the cysts to originate from the posterior joint capsule. It suggests that some of the ganglion arising from the posterior cruciate ligament reported in the literature might actually be from the posterior joint capsule. To prevent recurrence of a ganglion cyst, when preoperative MRI shows the mass to be located posterior to the cruciate ligaments, we recommend that the relationship of the ganglion cyst to the posterior joint capsule be evaluated at arthroscopy through the posteromedial or posterolateral portal.

Recurrent pretibial ganglion cyst formation over 5 years after anterior cruciate ligament reconstruction

Although ganglion cysts of the anterior cruciate ligament have been described in the literature, they are a relatively rare phenomenon. Cyst formation after anterior cruciate ligament reconstruction is even less frequent, with only a few reported cases. The proposed etiology of these cysts has been attributed to a number of causes, including the use of bioabsorbable screws, Gore-Tex (W. L. Gore and Associates, Flagstaff, AZ) grafts, extra-articular fluid extravasation secondary to direct tibial tunnel communication, allografts with or without ethylene oxide sterilization, and the use of nonabsorbable suture. We report an unusual case of a recurrent pretibial ganglion cyst that initially formed more than 5 years after an anterior cruciate ligament reconstruction and recurred 2 years after resection of the mass. We believe the initial surgical resection was unsuccessful probably because the foreign body irritant was not identified. Only after resection of the entire stalk of the cyst and removal of all of the inciting suture material that was found near the entrance of the tibial tunnel were we able to definitively eradicate the ganglion cyst.

A giant ganglion cyst that developed in the infrapatellar fat and partly extended into the knee joint

Ganglion cysts of the knee joint usually present near the lateral meniscus. Their size varies, and they may be encased in single or multiple capsules. Few case reports on ganglion cysts of the knee joint have been reported. We report a giant ganglion cyst that developed in the patellar fat and partly extended into the joint. The ganglion cyst was exposed in the meniscosynovial junction and was electrically evaporated at the anterior horn. No recurrence has occurred to date, and the patient has returned to his previous level of activity.

Unusual solid ganglia of the anterior cruciate ligament mimicking lateral meniscal tears

Previous investigators have reported incidental findings and symptomatic cases of cystic ganglia on the anterior cruciate ligament (ACL) that were mucinous degeneration or herniation of the synovial tissue through a defect. However, we report 2 cases of grossly solid ganglia of the ACL those mimicked lateral meniscal tears. A literature search found no previous report of them. We discuss the possibility of their pathogenesis and treatment.

Multiple ganglion cysts of the knee

Only solitary ganglion cysts within the knee have been reported. Multiple ganglion cysts within the same knee have not been reported. The author describes a patient with 2 ganglion cysts, one in the anterior cruciate ligament and one in the lateral meniscus of the same knee. Surgery was performed because of recurrent pain and functional disability.

Arthroscopic treatment of tumor-like lesions of the knee joint: Localized pigmented villonodular synovitis and ganglion cyst of the anterior cruciate ligament

We present the arthroscopic treatment of a case of localized pigmented villonodular synovitis that led to increasing restriction of knee flexion and the case of a ganglion cyst within the anterior cruciate ligament causing unspecific pain. Both pathologies could be resected arthroscopically with complete relief of symptoms and no recurrence. In cases with unspecific clinical signs and intra-articular masses shown on magnetic resonance imaging, arthroscopy is the next therapeutic step. Localized tumor-like lesions can often be excised without recurrence in the same session.

Cysts and other masses about the knee: identifying and treating common and rare lesions

Masses about the knee are most commonly benign cysts. The diagnosis can often be made with a history and physical exam, but radiographs and MRI are sometimes required, and histologic evaluation is occasionally necessary. Popliteal (Baker's) cysts are often indicative of arthritis; treatment for the underlying pathology may reduce swelling and permit resorption. Meniscal cysts indicate an underlying tear; treatment is resection and cyst excision. Symptomatic ganglion cysts generally require surgical excision. Treatment for bursitis is conservative. The less-common synovial chondromatosis, pigmented villonodular synovitis, synovial sarcoma, and lesions of the proximal tibiofibular joint generally require referral and surgery.

Intra-articular ganglion cysts of the knee

A ganglion is a cystic mass with myxoid matrix that occasionally occurs within muscles, tendons, and menisci. A ganglion cyst within the knee is very rare, with few reports to be found. We are reporting eight cases of a ganglion within the knee joint. Our cases include two ganglia in the infrapatellar fat pad which have not been previously reported. Ganglion cysts do not have specific symptoms. We hypothesize that symptoms of a ganglion cyst may correlate with the size and the location within the knee joint. The diagnosis of ganglia within the knee was established by magnetic resonance imaging study and confirmed by pathological testing. All the patients were treated successfully using the arthroscopic technique.

Technical report: CT-guided aspiration of anterior cruciate ligament ganglion cysts

We describe computed tomography (CT)-guided percutaneous anterior cruciate ligament (ACL) ganglion cyst aspiration in three patients. In so doing, we review clinical technique, patient outcomes and discuss advantages of radiologically guided intervention relative to traditional surgical incision and drainage.