Synovial Cysts Confounding Access to the Dorsal S1 Neural Foramen in Transforaminal Epidural Steroid Injections.

OBJECTIVES: The S1 dorsal foramen is the route for 30% of lumbar transforaminal epidural injections; it is therefore important to identify structures impeding S1 foraminal access. The study objective was to characterize the imaging findings, prevalence, and anatomic origin of synovial cysts presenting within the S1 neural foramen. METHODS: A case series (N = 14) established imaging characteristics of S1 synovial cysts. Imaging studies of 400 patients undergoing epidural injections were reviewed for lesions compromising S1 foraminal access. Cadaveric dissections defined the relationship of the inferior recess of the L5-S1 facet to the S1 dorsal foramen. RESULTS: Elderly patients (mean age = 76) exhibited S1 synovial cysts. Synovial cysts were typically 1-2 cm in diameter, hyperintense on sagittal T2 weighted magnetic resonance images (MRIs), fluid-density on computed tomography, and dorsal to the S1 spinal nerve. Sixty percent of cysts exhibited complex MRI signal characteristics (thick wall, internal structure). Tarlov cysts, in contrast, were larger, lobular, and exhibited pure fluid intensity. Lesions impeded access to the S1 dorsal foramina in 5% of reviewed imaging studies (16 Tarlov cysts, three synovial cysts, one conjoint S1-S2 nerve root). The multifidus muscle was interposed between the L5-S1 facet inferior recess and the S1 dorsal foramen on dissection specimens; severe atrophy of the ipsilateral multifidus was noted on imaging in 17/18 synovial cysts. CONCLUSIONS: The S1 neural foramina should be inspected on sagittal MRI, when available, for confounding lesions before performing S1 epidural injections. Tarlov cysts are more common than synovial cysts; the latter are seen in elderly patients with severe multifidus atrophy.

Synovial Cyst as a Marker for Lumbar Instability: A Systematic Review and Meta-Analysis.

BACKGROUND: The pathogenesis of synovial cysts is largely unknown; however, they have been increasingly thought of as markers of spinal facet instability and typically associated with degenerative spondylosis. We specifically investigated the incidence of concomitant synovial cysts with underlying degenerative spondylolisthesis. METHODS: A literature search was performed using 4 online databases to assess the association between lumbar synovial cysts and degenerative spinal pathological features. Meta-analyses were performed on the prevalence rates of coexisting degenerative spinal pathological entities and treatment modalities. A random effects model was used to calculate the mean and 95% confidence intervals. RESULTS: A total of 17 studies encompassing 824 cases met the inclusion criteria. The pooled prevalence rates of concurrent spondylolisthesis, facet arthropathy, and degenerative disc disease at the same level of the synovial cysts were 42.5% (range, 39.0%-46.1%), 89.3% (range, 79.0%-94.8%), and 48.8% (range, 43.8%-53.9%), respectively. Among these, patients with coexisting spondylolisthesis were more likely to undergo spinal fusion surgery (vs. laminectomy alone) and reoperation than were patients without spondylolisthesis with a pooled odds ratio of 11.5 (95% confidence interval, 4.5-29.1; P < 0.0001) and 2.0 (95% confidence interval, 0.9-4.2; P = 0.088), respectively. CONCLUSIONS: Patients with a combination of synovial cysts and degenerative spondylolisthesis are more likely to undergo spinal fusion surgery than laminectomy alone compared with patients with synovial cysts and no preoperative spondylolisthesis. Furthermore, patients with synovial cysts and spondylolisthesis are more likely to require additional fusion surgery. The results from the present review lend credence to the argument that synovial cyst herniation might be a manifestation of an unstable spinal level.

Degenerative symptomatic spinal synovial cysts: Clinical presentation and functional outcome.

Spinal synovial cysts (SSC) are a rare but important differential diagnosis for degenerative or space-occupying spinal lesions. There is controversy about the most beneficial treatment, which can be conservative or surgical. We provide a review of our surgical data for purposes of quality assessment and improvement. 5313 patients with surgically treated degenerative spinal diseases were analyzed retrospectively. The incidence of SSC was 1.14%. 61 patients (31 women, 30 men; mean age 65.3 years) with SSC were included in this study. The charts, surgical reports, and radiographic data were reviewed for demographics, duration of symptoms, size of SSC, anatomical site, surgical approach, Visual Analog Scale (VAS), and neurological performance including the Japanese Orthopedic Association Score (JOA score) and the Frankel score. Laminotomy was the most common surgical approach in 93.4% of the patients followed by hemilaminectomy in 6.6%. The predominant site of SSC was the lumbar spine in 86.9%. 95.1% had experienced local and radicular pain as the predominant symptom and 47.5% preoperative sensory and motor deficits. At discharge, the JOA score was significantly increased compared to admission (median value of 17). At follow-up, 94.4% had normal neurological function and 5.6% showed grade 1 neurological deficits. Leg pain had decreased in 94.4% and back pain in 70.6%. At long-term follow-up, all patients presented neurologically stable. The median value for pain classified with the VAS had decreased from 6 at admission to 1 at long-term follow-up. During long-term follow-up, 6 patients (9.8%) had developed spinal instability requiring stabilization, 5 patients had received facet joint infiltration due to symptomatic facet joint syndrome. The epidemiological and clinical patterns of symptomatic SSC are similar to those of other degenerative spinal diseases. Thus, SSC should always be considered as a rare but important differential diagnosis. Surgical outcome was excellent with immediate symptom relief and recovery, which further improved over time. Our data support the benefit of surgical treatment and may be useful in recommending neurosurgical therapy to patients with SSC.

The Prevalence of Incidental and Symptomatic Lumbar Synovial Facet Cysts.

STUDY DESIGN: This was a retrospective cohort study from 2 affiliated tertiary care referral centers for spine disease. OBJECTIVE: The purpose of this article was to assess the prevalence of incidental (ie, asymptomatic) and symptomatic lumbar synovial facet cysts on magnetic resonance imaging. Secondarily, we assessed whether the prevalence increases with age. In addition, we assessed differences in patient and cyst characteristics between asymptomatic and symptomatic facet cysts. SUMMARY OF BACKGROUND: The prevalence of symptomatic and asymptomatic synovial facet cysts in the lumbar spine has been incompletely established, and, although many studies demonstrate an association with degenerative spine disease, no cumulative increase in prevalence of synovial facet cysts with increasing age has been presented. METHODS: We included 19,010 consecutive patients who underwent a dedicated lumbar spine magnetic resonance imaging between 2004 and 2015. Our outcome measures were symptomatic and asymptomatic facet cysts. A symptomatic cyst was defined as a cyst with symptoms of radiculopathy on the same side as the cyst. RESULTS: The overall synovial facet cyst prevalence was 6.5% [95% confidence interval (CI), 6.1-6.8]; 46% of the facet cysts were incidental and 54% were symptomatic. Increased age was independently associated with a higher likelihood of having a synovial facet cyst [odds ratio (per 10 y), 1.24, 95% CI, 1.20-1.29; P<0.001]. Large cyst size (odds ratio, 1.64; 95% CI, 1.23-2.20; P=0.001) and anterior location (odds ratio, 1.39; 95% CI, 1.08-1.79; P=0.010) of the synovial facet cyst were the only factors independently associated with having radiculopathy. CONCLUSIONS: Approximately 1 in 15 patients have at least 1 synovial facet cyst. Having a facet cyst-symptomatic and asymptomatic-is strongly associated with increased age supporting the theory that degenerative disease underlies its development. Large cyst size and anterior location of the cyst are associated with an increased likelihood of having neurological symptoms. LEVEL OF EVIDENCE: Level III, diagnostic study.

Incidence and Risk Factors for Volar Wrist Ganglia in the U.S. Military and Civilian Populations.

PURPOSE: To identify the incidence and demographic factors associated with volar wrist ganglia in both military and civilian beneficiary populations. METHODS: The U.S. Department of Defense Management Analysis and Reporting Tool (M2) accesses a comprehensive database of all health care visits by military personnel and their dependents. Because there is no specific code for ganglions of the wrist, the database was searched for all military personnel and civilian beneficiaries with an International Classification of Diseases, 9th Revision, diagnosis of 727.41 (ganglion of a joint) or 727.43 (ganglion, unspecified location) between 2009 and 2014. Two random samples of 1000 patients were selected from both the military and the civilian beneficiary cohorts, and their electronic medical records were examined to identify those with volar wrist ganglia. The proportion of volar wrist ganglia was then applied to the overall population data to estimate the total incidence with a 95% confidence interval and 5% margin of error. Unadjusted incidence rates and adjusted incidence rate ratios were determined using Poisson regression, controlling for age, sex, branch of military service, and military seniority. RESULTS: The unadjusted incidence of volar wrist ganglia is 3.72 per 10,000 person-years (0.04%/y) in female civilian beneficiaries, 1.04 per 10,000 person-years (0.01%/y) in male civilian beneficiaries, 7.98 per 10,000 person-years (0.08%/y) in female military personnel, and 3.73 per 10,000 person-years (0.04%/y) in male military personnel. When controlled for age, military personnel have a 2.5-times increased rate of volar wrist ganglia, and women have a 2.3-times increased rate. In the military cohort, female sex, branch of service, and seniority were significantly associated with the diagnosis of a volar wrist ganglion when controlled for age. In the civilian beneficiary cohort, only female sex was significant. CONCLUSIONS: Military service members have higher rates of volar wrist ganglia diagnoses than their age- and sex-matched civilian counterparts. Women are significantly more likely to be diagnosed with a volar wrist ganglion, regardless of age or military status. CLINICAL RELEVANCE: The epidemiology of volar wrist ganglia is poorly defined, and few studies have firmly defined demographic factors associated with the diagnosis. We provide the overall incidence rate of the diagnosis and report a significant association with female sex even when controlled for age.

The incidence of dural tears after complete resection of lumbar synovial cysts and the relation to the outcome.

OBJECTIVE: Synovial cysts in the lumbar spine are uncommon causes of radicular pain. In cases where conservative treatment fails, surgical resection is recommended. Dural adhesions are common intraoperative findings; therefore, the removal of the cyst may sometimes result in dural tears. The frequency of dural tears is greater with synovial cysts than in other lumbar surgeries. Clinical parameters and characteristics seen on magnetic resonance imaging were assessed to investigate the correlation between the outcome after surgery of lumbar synovial cysts and dural tears. METHODS: This study was designed as a retrospective practice audit. Patient data were drawn from an electronic medical record system. Included were consecutive patients after microsurgical resection of symptomatic lumbar synovial cysts between May 2013 and November 2015. The surgical report was evaluated retrospectively regarding the extent of decompression and cyst resection as well as surgery-related complications. Pre-operative magnet resonance imaging was assessed concerning the reason for compression of the neural structures, the dimension of the cyst, and the signal of the cyst content in T2 images. In a follow-up examination about four weeks after surgery, the patient satisfaction index was evaluated. RESULTS: Forty-four consecutive patients after resection of a lumbar synovial cyst met the inclusion criteria. The mean patient satisfaction index was 2.0±1.0. Twenty-nine patients of the 38 patients with follow-up (76.3%) with a satisfaction index of 1 or 2 were rated as favorable. One revision surgery was necessary because of a cerebrospinal fluid fistula. Furthermore, in 4 patients an incidental durotomy occurred without any symptoms after surgery. Accordingly, the rate of dural tears was 11.4%. Dural tears were significantly more common in patients with a satisfaction index of 3 or 4 (P=0.04). Sixty percent of the patients with dural tears were operated on in level L5/S1 compared to 3 patients without a dural tear (P=0.008). There was no statistically significant difference between the different patient subgroups in any other analyzed parameter. CONCLUSION: Dural tears were found significantly more often in patients without a good outcome; they appear to portend a poorer prognosis. The level L5/S1 was significantly more often affected. During surgery, it should be considered whether to remove the cyst completely and risk a dural tear, or to leave residuals of the cyst wall if otherwise a good decompression is achieved.

Lumbar facet joint synovial cysts: does T2 signal intensity predict outcomes after percutaneous rupture?

BACKGROUND AND PURPOSE: Lumbar facet synovial cysts are a cause of back pain and radiculopathy with facet joint degeneration, the most common cause for cyst formation. Typically, LFSCs are T2 hyperintense on MR imaging, but the signal intensity is variable. Treatment options include percutaneous rupture and surgical resection. This study evaluates the relationship between LFSC signal intensity on MR imaging and outcomes as it relates to percutaneous rupture success and need for subsequent surgery. MATERIALS AND METHODS: A retrospective review of 110 patients who underwent CT fluoroscopic-guided rupture of symptomatic LFSCs was performed. The LFSCs were characterized by their T2 signal intensity on MR imaging and divided into 3 groups: high, intermediate, and low T2 signal intensity. The rates of successful cyst rupture and need for subsequent surgery were recorded. RESULTS: Percutaneous LFSC rupture was technically successful in 87% of all cases. Cyst rupture was successful in 89% and 90% of high and intermediate signal intensity cysts, respectively, and in 65% of low signal intensity cysts (P = .017, .030). High signal intensity cysts had lower postprocedural surgical rates (29%) when compared with intermediate and low signal cyst as a group (P = .045). CONCLUSIONS: T2 hyperintense and intermediate signal intensity LFSCs are easier to rupture, perhaps because the cysts contain a higher proportion of fluid and are less gelatinous or calcified than T2 hypointense cysts. Patients with T2 hyperintense LFSCs are less likely to need surgery.

The prevalence and pathogenesis of synovial cysts within the ligamentum flavum in patients with lumbar spinal stenosis and radiculopathy.

STUDY DESIGN: A clinicopathologic study of synovial cysts in the ligamentum flavum (LF) in patients with spinal stenosis. OBJECTIVE: To investigate the pathogenesis of lumbar juxtafacet cysts. SUMMARY OF BACKGROUND DATA: Contradictions in the terminology applied to lumbar juxtafacet cysts arise from the frequent sparsity of synovial lining cells, which has led to synovial cysts often being called "ganglion cysts" despite lacking confirmatory pathology. METHODS: A total of 27 consecutive patients with radiologically confirmed stenosis underwent laminectomy. LF/facet joint (FJ) relationships were retained by en bloc excision of the LF and the medial inferior FJ. Controls were LF/FJ specimens from 47 cadaver lumbar spines. RESULTS: The 27 patients yielded 51 LF/FJ specimens containing 28 synovial cysts, 12 of which were unilateral and 8 were bilateral. Fragments of articular cartilage and bone were embedded in the walls of 89% of cysts and in the walls of a bursa-like channel originating from the medial aspect of the FJ capsule and extending into the LF. Communication with the FJ via this channel was observed in 21 (75%) of the 28 synovial cysts. Extending up to 12 mm in length, the channel was present in nearly all control spines at the L4-L5 level but in only about half at the T12-L1 level. CONCLUSION: Cysts having an extensive or meagre synovial cell lining are common in the LF of patients with symptomatic lateral or central stenosis. The cysts communicate with the FJ by a bursa-type channel within the LF. Advanced osteoarthritis of the FJ causes the liberation of fragments of cartilage and bone into the synovial fluid of the joint space. This enables some fragments to escape from the joint into the channel and become lodged within its wall where they provoke granulation tissue and scar formation. The tissue response to articular debris may block the synovial-lined channel to cause synovial cyst formation.

Spinal lumbar synovial cysts. Diagnosis and management challenge.

Sophisticated and newer imaging capabilities have resulted in increased reporting and treatment options of spinal lumbar synovial cysts (LSS). Most of the patients with lumbar cysts tend to be in their sixth decade of life with a slight female predominance. The incidence of LSS is thought to be less than 0.5% of the general symptomatic population. They may be asymptomatic and found incidentally or the epidural growth of cysts into the spinal canal can cause compression of neural structures and hence associated clinical symptoms. Most of the symptomatic LSS patients present with radicular pain and neurological deficits. Spinal synovial cysts are commonly found at L4-5 level, the site of maximum mobility. They may be unilateral or bilateral and at one or multilevel. MRI is considered the tool of choice for its diagnosis. The etiology of LSS is still unclear, but underlying spinal instability, facet joint arthropathy and degenerative spondylolisthesis has a strong association for worsening symptoms and formation of spinal cysts. Synovial cysts resistant to conservative therapy should be treated surgically. Resection and decompression with or without fusion and instrumentation remains an appropriate option. Synovial cysts may recur following surgery. The optimal approach for patients with juxtafacet LSS remains unclear. The best surgical treatment option for each particular individual should be tailored depending upon the symptoms, radiological findings and other co morbidities.

[Juxta-facet cysts as a differential diagnosis for lumbar neuralgia]. / Facettengelenkzysten als eine Differenzialdiagnose bei Lumboischialgien.

AIM: The aim of the current investigation it was to evaluate the incidence, clinical symptoms and the results of surgical treatment of lumbar juxta-facet cysts. METHOD: Between January 2002 and July 2003 305 patients underwent decompression of the lumbar spinal canal. In 3.6 % of these (n = 11) juxta-facet cyst were found to be responsible for the complaints and resection of the cyst was performed. All patients underwent standardized clinical examination and pain evaluation by the means of a visual analogue scale in a follow-up of 6.8 month on average. RESULTS: The average history of lumbar pain was 26 months, that of leg pain 23 weeks, respectively. Radicular symptoms appeared in 7 patients, and 9 of 11 patients complained about spinal claudication. Clinical examination showed a typical pain provocation during reclination of the lumbar spine. However none showed a segmental instability. Preoperative MRI revealed facet cysts with an average diameter of 9 mm (4-18 mm). All of the patients showed signs of degenerative spondylarthritis. Postoperative examination revealed in 8 cases a very good and in 2 cases a good result. One patient complained about persisting sciatica in spite of MR-tomographic demonstration of complete resection of the cyst. The walking-distance improved by least 50 % in 10 cases. Although no spinal fusion was performed, no patient developed a postoperative segmental instability. CONCLUSION: Juxta-facet cysts represent a not uncommon differential diagnosis in patients with lumbar radiculopathy. In the case of missing signs of segmental instability, resection of the cyst without simultaneous spinal fusion seems to be an appropriate therapy.

Synovial cysts of the lumbar facet joints in a symptomatic population: prevalence on magnetic resonance imaging.

STUDY DESIGN: A retrospective review of 303 MRI scans of the lumbar spine was conducted. OBJECTIVES: To determine the prevalence of lumbar facet joint synovial cysts arising from the joints anteriorly and posteriorly. To examine the association of these cysts with facet joint osteoarthritis and degenerative disc disease. SUMMARY OF BACKGROUND DATA: Sporadic reports of such cysts exist as do limited studies describing the prevalence of symptomatic anterior facet joint synovial cysts. However, the overall prevalence of lumbar facet joint synovial cysts has not been formally studied, and the mechanism of formation of these cysts is not fully understood. METHODS: One observer undertook a review of MRI of the lumbar spine from one facility in a series of 303 patients referred mostly for back pain or radiculopathy. The presence of lumbar facet joint synovial cysts, their relationship to the facet joint, the degree of associated facet joint osteoarthritis, the presence of spondylolisthesis, and the degree of associated disc degeneration were recorded. RESULTS: Seven anterior cysts (prevalence = 2.3%) were identified, only two of which did not clearly cause nerve root compression. Twenty-three posterior cysts in 22 patients (prevalence = 7.3%) were identified. Statistically significant associations with increased frequency and severity of facet joint osteoarthritis and with spondylolisthesis were demonstrated compared to patients without cysts. CONCLUSIONS: Both anterior and posterior lumbar facet joint synovial cysts are rare. Posterior cysts are more common than anterior cysts. Both types of cysts are related to facet joint osteoarthritis but not to disc disease.

Tumores sinoviales benignos en un área sanitaria gallegadurante la década 1992-2002 / Benign synovial tumors in a health area of Galicia (Spain) from 1992-2002

Fundamento: Las neoplasias sinoviales benignas son infrecuentes y no existe información sobre su epidemiología dentro de nuestra área sanitaria. Objetivo: Estudiar la frecuencia y las características de las neoplasias sinoviales benignas en la población adulta de nuestro sector sanitario. Material y métodos: Análisis retrospectivo de las historias clínicas de los adultos pertenecientes al área sanitaria de POVISA con diagnóstico histológico de neoplasia sinovial benigna, incluida la sinovitis villonodular (SVN), entre el 1 de enero de 1992 y el 30 de diciembre de 2001.Resultados: Se diagnosticaron 35 neoplasias benignas (2 lipomas, 1 fibroma, 2 hemangiomas y 30 SVN), una por paciente. La edad de los pacientes osciló entre 17 y 74 años (media ñ desviación estandar [DE]) y 27 (69 por ciento) fueron varones. La incidencia media fue de 3,5 casos/105 habitantes/año. Se recogieron 30 SVN, 21 de localización articular (13 difusas y 8 focales) y 9 que afectaban a las vainas tendinosas, sobre todo la del flexor del índice derecho (4 casos). En 24 pacientes (69 por ciento) los tumores se situaron en articulaciones, especialmente en la rodilla (21/24; 87,5 por ciento). Excepto un líquido sinovial xantocrómico o hemático (un hemangioma y algunas SVN articulares), las restantes manifestaciones clínicas fueron inespecíficas. La técnica radiológica de mayor rendimiento fue la resonancia magnética, realizada en los lipomas, en 13 de las 15 SVN articulares, en 3 SVN de las vainas tendinosas y en un hemangioma. Este último, situado en la rodilla izquierda de un varón de 21 años, no pudo ser operado por su extensión a los tejidos periarticulares y vasto medio. Las demás neoplasias fueron intervenidas quirúrgicamente. Los 21 pacientes con SVN articular fueron sometidos a sinovectomía (artroscópica en 7 y quirúrgica en 14). El procedimiento artroscópico tuvo más recidivas (3/7; [43 por ciento], frente a 2/14; [14 por ciento]). Conclusiones: La SVN articular tiene mayor incidencia en nuestra área sanitaria que la recogida en otros estudios epidemiológicos. Las restantes neoplasias sinoviales benignas fueron poco frecuentes y sus manifestaciones clínicas inespecíficas. La resonancia magnética es la técnica de imagen de elección para su estudio. La sinovectomía artroscópica en la SVN tuvo una tasa elevada de recidivas (43 por ciento) (AU)

Prevalence and size of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections in asymptomatic knees on MR imaging.

OBJECTIVE: The purposes of this study were to evaluate the prevalence and determine the size of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections on MR images of asymptomatic knees. MATERIALS AND METHODS: MR images of 102 asymptomatic knees were evaluated with regard to the prevalence of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections. The MR examinations were performed in patients (mean age, 42.8 years; age range, 18-73 years) with clinically suspected meniscal lesions in the contralateral knee. The craniocaudal, anteroposterior, and mediolateral diameters of detectable abnormal fluid collections were measured. RESULTS: Medial meniscal cysts (mean size [craniocaudal x anteroposterior x mediolateral], 9 x 6 x 13 mm) were found in four asymptomatic knees. Neither lateral meniscal cysts nor ganglionic cysts of the cruciate ligaments were identified. Twenty-six synovial cysts of the popliteal space (Baker's cyst)-consisting of 11 gastrocnemius portions (mean size, 19 x 8 x 10 mm) and 15 semimembranosus portions (mean size, 20 x 7 x 9 mm)-were found in 19 knees. Twenty-four (92%) of these cysts had a maximal diameter of 30 mm or less. Fluid-filled bursae were found in 49 knees. The deep infrapatellar bursa was most commonly involved (42 knees; mean size, 6 x 3 x 5 mm). Fluid-filled anserine bursae (mean size, 27 x 12 x 10 mm) were detected in five knees. CONCLUSION: Meniscal cysts may be present in asymptomatic knees, at least on the medial side. Synovial cysts of the popliteal space can be found in approximately one fifth of asymptomatic knees. Their maximal diameter is usually smaller than 30 mm.

Morphology and topography of intraosseous ganglion cysts in the carpus: an anatomic, histopathologic, and magnetic resonance imaging correlation study.

PURPOSE: To assess the morphology, topography, frequency, and etiology of intraosseous carpal ganglions. METHOD: Two hundred and eighty formalin fixed cadaveric wrists (mean age 80.3 +/- 9.7 years, range 40 to 101 years) were radiographed. Fifty specimens suspicious for cyst-like bone lesions underwent magnetic resonance imaging (T1w and proton density-fat-saturated images, 1.5T). Dissection, articular surface assessment, and histological examination were performed. Cystic lesions with adjacent destruction of the hyaline cartilage were classified as degenerative and were excluded. RESULTS: In 27 of the 50 specimens, 48 ganglion cysts (GC) were found. Prevalence of GC was 9.6%. Of 48 intraosseous carpal GC, 41 (85%) were in a peripheral location; 27/48 (56%) were located at the palmar carpus. GC had a macroscopic and microscopic relationship to the insertion of degenerated ligaments. They developed near longitudinally orientated bone surfaces, which serve as insertion for ligaments and are exposed to tension loading. CONCLUSIONS: Unlike degenerative cysts, ganglion cysts do not erode the hyaline articular cartilage and almost always have a continuity with the capsular ligaments. Intraosseous carpal ganglion cysts are probably the result of mucoid degeneration of adjacent ligaments.

[Arthroscopic treatment of a Hoffa ligament cyst]. / Traitement arthroscopique d'un kyste du ligament de Hoffa.

Cysts of Hoffa's ligament are exceptional. Twelve cases have been reported in the literature, two of which were treated arthroscopically. We report the first case in the French literature. A 21-year-old woman developed an atypical cystic formation of the knee. The diagnosis of ganglion cyst of Hoffa's ligament was strongly suggested at magnetic resonance imaging and confirmed at arthroscopy. We recall the different epidemiologic, pathogenic, clinical and radiological aspects of this condition and emphasize the importance of MRI for the differential diagnosis with other tumors.

Bilateral ganglion cyst of the common peroneal nerve.

Ganglion cysts of the common peroneal nerve are rarely described in the literature and a bilateral lesion has not been previously reported. We present a case of a 41-year-old man with a bilateral cyst of the common peroneal nerve diagnosed with ultrasound and magnetic resonance imaging.

Radicular pain caused by synovial cyst: an underdiagnosed entity in the elderly?

OBJECT: Synovial cyst is a recognized but infrequent cause of nerve root or spinal canal compression. The authors undertook a review of 839 decompressive spinal procedures performed over a 5-year period. They found seven cases in which the symptoms were caused by synovial cysts. METHODS: Six of these cases were in a subgroup of 80 patients who were older than 60 years of age, which represents 7.5% of the total for this age group. More than 200 cases of this abnormality have been reported in the world literature, but the incidence, prevalence, and natural history remain unknown. CONCLUSIONS: The authors propose that the incidence of synovial cysts may be more common than recognized in the elderly and suggest that preoperative diagnosis may help limit the extent of the surgical approach.

Case report ganglion cysts of the bilateral cruciate ligaments.

Ganglion cysts originating from the cruciate ligaments have been reported rarely. A 38-year-old woman developed symptoms of knee pain with 10 degrees loss of knee extension. Preoperative magnetic resonance imaging showed a well-demarcated cystic mass surrounding the posterior cruciate ligament so clearly that further examination was not recommended. Because examination under anesthesia confirmed full extension of the knee, we presumed that pain produced by compression caused the diminished extension, and that mechanical block was not the reason. During arthroscopic examination, a mass was impinged between the anterior cruciate ligament and the intercondylar notch when extension of the knee was attempted. The mass was resected and immediate improvement was noted. The patient had experienced the same episode in the contralateral knee and removal of a ganglion cyst on the cruciate ligament 10 years ago. At the latest follow-up she was completely symptom free in both knees without any sign of recurrence.

The incidence of ganglion cysts and other variations in anatomy along the course of the suprascapular nerve.

When the diagnosis of suprascapular nerve entrapment syndrome is being considered, variations in anatomy are possible etiologic factors. Seventy-nine shoulders from 41 cadavers were examined for anatomic variations and for ganglion cyst formation in the suprascapular notch, superior transverse scapular ligament, and inferior transverse scapular ligament. The morphologic evaluation of the suprascapular notch revealed a "U" shape in 77% and a "V" shape in 23%, with 89% of cadavers having the same notch shape bilaterally. In 23% of shoulders a variation of the superior transverse scapular ligament was demonstrated such as partial and complete ossification and multiple bands including the first report of a trifid superior transverse scapular ligament. An inferior transverse scapular ligament was observed in only 14% of shoulders. One ganglion cyst was identified, for an incidence of 1%. The mass was located in the supraspinatus fossa adjacent to the superior transverse scapular ligament and appeared to compress and alter the course of the suprascapular nerve. When operative treatment is elected for suprascapular nerve entrapment syndrome and an open surgical approach is undertaken, the location and source of disease and morphologic and anatomic variants must be recognized to ensure adequate access and complete decompression of the suprascapular nerve. The classical description of the superior transverse scapular ligament as a completely nonossified single band should be expected, on average, in approximately three fourths of the cases. Partial or complete ossification and anomalous bands of the superior transverse scapular ligament or a ganglion cyst along the course of the suprascapular nerve may be encountered. Although a superior transverse scapular ligament should be anticipated in all shoulders, an inferior transverse scapular ligament will be a much less frequent finding. The role and significance of suprascapular notch morphologic characteristics warrant further investigation.