Extra-articular Location Research Articles

Extra-articular location of the three-dimensional mechanical axis in advanced knee osteoarthritis: an upright computed tomography study.

One of the most widely used benchmarks of lower-limb alignment is the mechanical axis (MA), which passes through the centers of the femoral head and the ankle in the weight-bearing position. However, where the MA passes through three-dimensionally (3D) is unclear. We investigated the MA in 3D (3D-MA) in knee osteoarthritis (OA) using upright computed tomography (CT). This study included 66 varus OA knees from 38 patients [age 70.0 (64.8-77.0) years; median (interquartile range)]. The 3D-MA was determined using upright CT data and compared among Kellgren-Lawrence (KL) grades. Further, correlations between the 3D-MA and other parameters were evaluated. The 3D-MA was located at 5.3 (1.3-14.4)% medially and 7.1 (0.7-15.3)% posteriorly on the tibial plateau in KL-1, and was translated medioposteriorly with increased KL grade. The 3D-MA in KL-3 [30.6 (22.6-42.6)% medially and 50.9 (45.8-80.2)% posteriorly] and KL-4 [56.7 (48.5-62.9)% medially and 92.3 (50.2-127.1)% posteriorly] was located extra-articularly. The mediolateral position of the 3D-MA correlated with the femorotibial angle [correlation coefficient (CC) = -0.85, p < 0.001], and the anteroposterior position of the 3D-MA correlated with the knee flexion angle (CC = -0.93, p < 0.001). Our analysis demonstrated that the 3D-MA in low-grade OA knees passes slightly medial and posterior to the knee center, and the 3D-MA is translated medioposteriorly with the progression of knee OA. Further, the 3D-MA is translated medially with varus progression and posteriorly with the progression of knee flexion contracture.

MRI Prediction Model for Tenosynovial Giant Cell Tumor with Risk of Diffuse-type

To propose a magnetic resonance imaging (MRI) prediction model for diffuse-type tenosynovial giant cell tumors (D-TSGCTs). Anatomic locations were classified and then nodularity, margin, peripheral and internal hypointensity, and bone and cartilage involvement were evaluated on MRI. Student's t-test, chi-square test, diagnostic performance, logistic regression analysis, and decision tree were performed. Nineteen intra-articular (11 localized; eight diffuse) and 55 extra-articular (44 localized; 11 diffuse) TSGCTs were included. Extra-articular D-TSGCTs showed significantly more frequent multinodular (72.7% vs. 25.0%, p=0.009), and infiltrative lesions (90.9% vs. 34.1%, p=0.002), without peripheral hypointensity (90.9% vs. 18.2%, p < 0.001), and contained granular internal hypointensity (72.7% vs. 31.8%; p=0.003) with more frequent bone (81.8% vs. 27.3%; p=0.003) and cartilage (50.0% vs. 0.0%; p=0.038) involvement than localized-type. Intra-articular D-TSGCT also showed significance in all MRI features (100.0% vs. 9.1%, p=0.001; 100.0% vs. 27.3%, p=0.007; 100.0% vs. 36.4%, p=0.018; 100.0% vs. 27.3%, p=0.007; 50.0% vs. 0.0%, p=0.038), except bone involvement (37.5% vs. 9.1%, p=0.352) than localized-type. Cartilage involvement revealed the highest specificity (88.6-100.0%), regardless of location. Nodularity (100.0%; odds-ratio [OR]: 70.000) and peripheral hypointensity (90.9%; OR: 62.250) demonstrated the highest sensitivities ORs for D-TSGCT in intra-articular and extra-articular cases, respectively. MRI models for D-TSGCG beginning with the cartilage involvement in both anatomic locations and next on nodularity and peripheral hypointensity in intra-articular and extra-articular locations, respectively, exhibited sensitivity and specificity of 100% and 90.9% for intra-articular and 100% and 77.2% for extra-articular TSGCTs, respectively. MRI can suggest the risk of D-TSGCT by combining imaging features with anatomic locations.

Пигментный ворсинчато-узловой синовит субарокмиального пространства (случай из клинической практики)

Pigmented villonodular synovitis (PVNS) is a rare benign proliferative disorder affecting synovial membranes, bursae, tendons, skin and bone. Materials The article presents a rare clinical case treated for PVNS of the subacromial space. The patient complained of pain in the shoulder joint at the largest possible points, and a deformity developed 7 months prior to the visit could be visualized at the anterior aspect of the shoulder joint. The patient denied any history of trauma. Arthroscopy of the shoulder joint was performed to rule out the intra-articular nature of the lesion with an exploratory puncture performed to establish the diagnosis with instrumental methods. Delto-pectoral approach was used to remove the neoplasm that was histologically examined to confirm the diagnosis. The upper limb was postoperatively immobilized with a Gilchrist-bandage for 2 weeks. The sutures were removed 2 weeks after the operation. Result The patient underwent a course of rehabilitation to restore the function of the upper limb. The upper limb function was preoperatively and postoperatively evaluated with the ASES questionnaire. The patient showed the shoulder function completely regained at two years with ASES scored 100. MRI scan of the shoulder joint showed no signs of recurrence. Extra-articular location of PVNS is very rare and is described in few case reports. Open procedure or arthroscopic removal of the affected synovial membrane are used to treat the condition. Conclusion Removal of the affected synovial membrane allowed us to obtain a good clinical result.

Fengshi Qutong capsule ameliorates bone destruction of experimental rheumatoid arthritis by inhibiting osteoclastogenesis

Ethnopharmacological relevanceBone destruction plays a key role in damaging the joint function of rheumatoid arthritis (RA). Fengshi Qutong capsule (FSQTC) consisting of 19 traditional Chinese medicines has been used for treating RA in China for many years. Preliminary studies show that FSQTC has analgesic activity and inhibits synovial angiogenesis of collagen-induced arthritis (CIA), but its role on bone destruction of RA is still unclear. Aim of the studyTo explore the effect of FSQTC on bone destruction of RA and the possible mechanism of osteoclastogenesis in vivo and in vitro. Materials and methodsLC-MS system was used to detect the quality control components of FSQTC. The anti-arthritic effect of FSQTC on CIA rats was evaluated by arthritis score, arthritis incidence and histopathology evaluation of inflamed joints. The effect of treatment with FSQTC on bone destruction of joint tissues was determined with X-ray and micro-CT quantification, and on bone resorption marker CTX-I and formation marker osteocalcin in sera were detected by ELISA. Then, osteoclast differentiation and mature were evaluated by TRAP staining, actin ring immunofluorescence and bone resorption assay both in joints and RANKL-induced RAW264.7 cells. In addition, RANKL, OPG, IL-1β and TNFα in sera were evaluated by ELISA. The molecular mechanisms of the inhibitions were elucidated by analyzing the protein and gene expression of osteoclastic markers CTSK, MMP-9 and β3-Integrin, transcriptional factors c-Fos and NFATc1, as well as phosphorylation of ERK1/2, JNK and P38 in joints and in RANKL-induced RAW264.7 cells using western blot and/or qPCR. ResultsIn this study, 12 major quality control components were identified. Our data showed that FSQTC significantly increased bone mineral density, volume fraction, trabecular thickness, and decreased trabecular separation of inflamed joints both at periarticular and extra-articular locations in CIA rats. FSQTC also diminished the level of CTX-I and simultaneously increased osteocalcin in sera of CIA rats. The effects were accompanied by reductions of osteoclast differentiation, bone resorption, and expression of osteoclastic markers (CTSK, MMP-9 and β3-Integrin) in joints. Interestingly, FSQTC treatment could reduce the protein level of RANKL, increase the expression of OPG, and decrease the ratio of RANKL to OPG in inflamed joints and sera of CIA rats. In addition, FSQTC inhibited the levels of pro-inflammatory cytokines implicated in bone resorption, such as IL-1β and TNFα in sera. When RAW264.7 cells were treated with RANKL, FSQTC inhibited the formation of TRAP + multinucleated cells, actin ring and the bone-resorbing activity in dose-dependent manners. Furthermore, FSQTC reduced the RANKL-induced expression of osteoclastic genes and proteins and transcriptional factors (c-Fos and NFATc1), as well as phosphorylation of mitogen-activated protein kinases (MAPKs). ConclusionFSQTC may inhibit bone destruction of RA by its anti-osteoclastogenic activity both in vivo and in vitro.

Rare localization of synovial cyst of the retroachilles bursa

Synovial cyst of the retroachilles bursa is a cystic formation developing from the retroachilles bursa. It is a rare cause of talalgia which has been very little reported in the literature. We report the case of a 22-year-old woman suffering from rebel left talalgia resistant to medical treatment. Left foot X-ray showed sharp and protruding bony outgrowth above and behind the great calcanean tuberosity. Chauveaux-Liet angle was 16 degrees and the Fowler-Philip angle was 82 degrees. The diagnosis of Haglund's deformity was retained. Dorsal surgery was performed. The cyst of the retroachilles bursa was removed and sent to the laboratory for anatomopathological examination. This confirmed the diagnosis of synovial cyst. The surgical gesture was complemented by removal of bony outgrowth. Patient's clinical outcome was favorable. This study reports a rare and unusual case of synovial cyst in an extra-articular location, complicating Haglund's deformity.

Arthroscopic management of synovial chondromatosis of the shoulder: a systematic review of literature.

Synovial chondromatosis (SC) of the shoulder is rare, with limited literature on its management. This systematic review of literature aimed to characterize common arthroscopic techniques for the treatment of shoulder SC and patient outcomes. We hypothesized that arthroscopy is an effective operative modality for the management of shoulder SC. PubMed and Embase databases were searched for articles on arthroscopic management of shoulder SC, published before 6 August 2020. All articles meeting inclusion criteria received an independent full-text review by two authors. An initial search found 64 articles. Following duplicate removal and title, abstract, and full-text reviews, 27 articles (48 patients) remained eligible. The mean age of patients was 33.0 years, with 2:1 male-to-female ratio. The mean follow-up was 41.8 months. SC was found to affect various intra- and extra-articular locations of the shoulder. Overall, arthroscopic treatment of shoulder SC was successful in 70.8%. Treatment failure was common in SC involving the bicipital tendon sheath. Disease recurrence was seen in 14.7%. Literature on arthroscopic management of shoulder SC is limited, and significant heterogeneity in arthroscopic techniques was observed. Although arthroscopic management of shoulder SC is effective, further optimization is necessary to minimize treatment failure and disease recurrence.

Osteochondroma of Hoffa’s fat pad

Infrapetellar osteochondroma is a rare benign osteochondromatous proliferation involving the infrapatellar fat pad. The pathogenesis of these lesions is unclear, but is thought to result from metaplasia of mesenchymal cells as a consequence of chronic infra-patella fat pad infringement or end stage of Hoffa’s disease1. Given its uncommon occurrence, it can be mistaken for more common conditions about the knee. The extra-articular location is distinct from cartilaginous loose bodies and synovial chondromatosis, which involve the joint space. Despite the name, this condition is not related to osteochondroma of bone. We report a case of infrapatellar fat pad osteochondroma and discuss features to distinguish this condition from morphologically similar lesions. Reference 1.Turhan E, Doral MN, Atay AO, et al. A giant extrasynovial osteochondroma in the infrapatellar fat pad: end stage Hoffa's disease. Arch Orthop Trauma Surg 2008; 128: 515–9.

The dual subscapularis procedure: a modified Hawkins' technique for neglected posterior fracture/dislocation of the shoulder.

Posterior fracture/dislocation of the shoulder is a rare injury that is frequently missed on initial assessment. It is frequently associated with reverse Hill-Sachs impression fracture. Several orthopaedics procedures have been described on the literature for reconstructable reverse Hill-Sachs lesion. The McLaughlin's procedure and its modifications, anatomic bone grafting procedures, rotational osteotomies, and the remplissage technique were reported by many authors. We advocated a new "dual subscapularis procedure" that consists of the Hawkins lesser tuberosity transfer with addition of filling the remainder of the defect with a part of subscapularis tendon. In the period between January 2013 to December 2017, 12 patients (13 shoulders) suffering from a delayed managed posterior fracture dislocation were managed. Our inclusion criteria were adult patients less than 60years presented with reverse Hill-Sachs impression defects from 20 to 50% with or without fractures. For all patients, the dual subscapularis procedure was done. UCLA score was used for postoperative functional assessment. After a minimum follow-up of 6months, the results of UCLA score were excellent/good in eight patients and fair/poor in five patients. All patients were found stable after open reduction ± internal fixation with no reported complications. There was a significant correlation of the UCLA score and non-abuse or lower doses of tramadol and the shorter interval between trauma and procedure. Twelve patients were satisfied after the operation. Reconstructing the reverse Hill-Sachs defect with the dual subscapularis technique provides adequate stability, pain relief, and function in patients with locked chronic posterior shoulder fracture/dislocation. The used technique has the merit of versatility with different fracture patterns, improved fixation of the tendon and increasing the tendon's footprint that ensures extra-articular location of the defect. II.

Distal Knee Medial Collateral Ligament Repair With Suture Augmentation

The medial collateral ligament (MCL) is the most commonly injured ligament of the knee. Given its extra-articular location, the MCL has great healing capacity such that the mainstay of treatment for most injuries remains conservative management. However, certain injury patterns place patients and athletes at risk of residual valgus laxity, which may require delayed surgical care and prolonged time out from sports. As such, identifying the specific injuries known to place patients at risk for failure with nonoperative management is of paramount importance. Although controversy remains regarding the optimal treatment of grade III MCL injuries, it is generally accepted that MCL ruptures from the distal tibia attachment require operative fixation. This technique article with accompanying video provides a detailed description of a technique for repairing the distal MCL attachment with suture augmentation. There are several advantages associated with an augmented direct repair including early, safe rehabilitation; prevention of valgus instability; and avoiding the comorbidities associated with a larger reconstruction.

Clinical and radiological outcomes after Weil osteotomy compared to distal metatarsal metaphyseal osteotomy in the treatment of metatarsalgia—A prospective study

BackgroundThe distal metatarsal metaphyseal osteotomy (DMMO) may have lower complication rates than the Weil osteotomy (WO) due to its extraarticular location and its minimal invasive nature. This study compares the clinical and radiological outcomes and complications after DMMO and WO. MethodsWe compared 30 patients with WO (Group A) to 30 patients with DMMO (Group B). Ten males and 50 females with a mean age of 57.7 were included. 45 WOs and 73 DMMOs were evaluated in 60 patients.Allocation to Group A or B were random, indications comparable.The outcome was measured clinically using the Visual Analogue Scale Foot and Ankle and radiologically with an average follow up period of 13 months. ResultsClinical examination six weeks postoperatively showed swelling of the forefoot in 66.7% for Group A and in 73.3% for Group B. Swelling subsided in the course of time, but postoperative stiffness, lack of toe purchase and range of motion deficits did not change in the course of time. All osteotomies healed. The VAS-FA improved for both groups. Tourniquet time and operating time were lower and radiation doses higher in Group B. ConclusionsThe DMMO resulted in a comparable patient satisfaction and comparable radiological healing compared to WO and appears to be a valid alternative to the WO.

Identifying and Exposing the Proximal Biceps in Its Groove: The “Slit” Technique

Proximal biceps tendon pathology is a common source of shoulder symptoms. Thus, visualization of the entire extent of the biceps tendon is often required for both diagnostic and therapeutic purposes. Accurately recognizing the presence and extent of biceps pathology intraoperatively is made more difficult, however, due to the extra-articular location of a significant portion of the biceps tendon as it courses within the bicipital groove. Unfortunately, identification of the biceps groove in the subacromial space is often challenging due to the lack of visual and tactile landmarks. A technique that facilitates efficient and reliable bicipital groove identification and biceps tendon visualization along its entire course within the groove is presented.

Condromatosis sinovial extraarticular de pie. Reporte de un caso y revisión de la bibliografía.

La condromatosis sinovial es una lesión poco frecuente caracterizada por la metaplasia cartilaginosa de la membrana sinovial de pequeñas y grandes articulaciones. Se suelen observar múltiples nódulos cartilaginosos y un grado variable de destrucción articular. Las manifestaciones clínicas son variables y dependen de la localización y el estadio de la enfermedad. Nuestra paciente concurrió con una tumoración en la planta del pie a nivel de la raíz del segundo y tercer dedo, de meses de evolución. Luego de los estudios por imágenes correspondientes y evidenciar la extensión dorsal de la lesión, se decidió realizar la resección en bloque a través de doble abordaje; el análisis anatomopatológico informó condromatosis sinovial. La ausencia de extensión intrarticular fue constatada en la cirugía. Este caso representa una manifestación poco frecuente de la patología no solo por su localización, sino también por su ubicación extrarticular. Según nuestra búsqueda bibliográfica, no se han publicado reportes de casos con condromatosis sinovial extrarticular avanzada (grado 3) en el antepié y creemos que debería ser considerada dentro de las lesiones tumorales de aspecto cartilaginoso en esta localización.

Correlation of clinical outcomes with bremsstrahlung and Y-90 PET/CT imaging findings following Y-90 radiosynoviorthesis: a prospective study

BackgroundIt is unclear how to predict which patients will respond to Y-90 radiosynoviorthesis. The aim of this study is to correlate clinical outcomes following Y-90 radiosynoviorthesis with bremsstrahlung and Y-90 PET/CT imaging findings.MethodsFifty-one joints underwent bremsstrahlung planar and Y-90 PET/CT imaging following Y-90 radiosynoviorthesis. The Y-90 distribution pattern on bremsstrahlung planar imaging was classified as diffuse or non-diffuse and compared with the intra or extra-articular location of activity on Y-90 PET/CT. Treatment response was assessed by patients and clinicians at 6 months. In patients who underwent bremsstrahlung SPECT, side-by-side comparison with PET was performed with image quality/resolution scored using a five-point-scale.FindingsBremsstrahlung planar images were classified as diffuse in 33/51 (65 %) and non-diffuse in 18/51 (35 %) scans. There was no association between treatment response and the bremsstrahlung planar imaging pattern. PET/CT confirmed an intra-articular location in all 33/33 (100 %) diffuse scans and an extra-articular location in 3/18 (17 %) non-diffuse scans. Of the three joints with extra-articular activity, none had any treatment response. Excluding these three joints, there remained no association between the bremsstrahlung planar imaging pattern and treatment response. Of the 42 joints imaged with SPECT, PET image quality/resolution was classified as superior in 40 (95 %). In one patient with extra-articular activity on PET/CT, SPECT/CT was unable to definitively localise the activity to the intra or extra-articular space.ConclusionsThe distribution pattern on bremsstrahlung planar imaging did not correlate with clinical outcome following Y-90 radiosynoviorthesis in our study population. However, in patients with non-diffuse planar imaging patterns, Y-90 PET/CT should be considered to exclude extra-articular activity with PET providing superior image quality compared to SPECT.

Total Saponin from Anemone flaccida Fr. Schmidt Prevents Bone Destruction in Experimental Rheumatoid Arthritis via Inhibiting Osteoclastogenesis.

Anemone flaccida Fr. Schmidt is used in the clinical compound prescription for the treatment of rheumatoid arthritis (RA) in China and has the traditional use of draining dampness, diminishing swelling, and relieving pain. Total saponins (TS) are the characteristic components and also the main active ingredients of A. flaccida. Previous reports indicated that TS possess anti-inflammatory and immunoregulatory properties; however, the effects of TS on bone destruction of RA have not been evaluated. In this study, our data first showed the therapeutic effects of TS on severity of arthritis and arthritis progression in collagen-induced arthritis (CIA) rats. Then, by microfocal computed tomography (CT) quantification, TS significantly increased bone mineral density, bone volume fraction, and trabecular thickness and decreased trabecular separation of inflamed joints both at peri-articular and extra-articular locations. TS also diminished the level of the bone resorption marker CTX-I and simultaneously increased the bone formation marker osteocalcin in sera of CIA rats. Interestingly, TS prevented bone destruction by reducing the number of osteoclasts in inflamed joints, reducing the expression of receptor activator of nuclear factor-κF (RANK) ligand (RANKL) and RANK, increasing the expression of osteoprotegerin (OPG), at both mRNA and protein levels, and decreasing the ratio of RANKL to OPG in inflamed joints and sera of CIA rats. This was further confirmed in the co-culture system of human fibroblast-like synovial and peripheral blood mononuclear cells. In addition, TS inhibited the levels of pro-inflammatory cytokines implicated in bone resorption, such as interleukin-1β (IL-1β), tumor necrosis factor-α (TNFα), IL-6, IL-17, and IL-23 in sera and joints. These findings offer convincing evidence that TS attenuate RA partially by preventing both focal bone destruction and systemic bone loss. This anti-erosive effect results in part from inhibiting osteoclastogenesis by regulating the RANKL/RANK/OPG signaling pathway. The suppression of systemic and local pro-osteoclastogenic cytokines by TS was also highly effective.

Sonographic Examination of Knee Ligaments.

Sonographic Examination of Knee Ligaments.

Magnetic Resonance Imaging Assessment of Temporomandibular Joint Involvement and Mandibular Growth Following Corticosteroid Injection in Juvenile Idiopathic Arthritis.

To assess whether intraarticular corticosteroid injection (CSI) reduces inflammation of the temporomandibular joint (TMJ), prevents growth disturbances of the mandibular condyle, and restores normal growth of the mandibular ramus. Retrospective longitudinal magnetic resonance imaging (MRI) evaluation of inflammatory activity, TMJ deformity, and mandibular ramus height in 33 children (23 girls, median age 5.2 yrs) over a median period of 5 years following repetitive CSI to the TMJ. Intraarticular location of CSI led to inflammatory grade improvement in 53% at first MRI followup compared to 20% with extraarticular location (p = 0.005), with more improvement of the mean inflammatory grade after intraarticular CSI (p = 0.001). Rate of osseous deformities of the TMJ deteriorated from 51% at study inclusion to 62% at end of observation period, with progression to severe condylar destruction in 26% of joints including 24% with development of intraarticular calcifications/ossifications. Mean short-term growth rates of the mandibular ramus were negative for intraarticular CSI while positive for extraarticular CSI (p = 0.036). Mean longterm mandibular ramus growth rate (0.7 ± 0.8 mm/yr) after CSI was significantly lower than reported normal mean age- and sex-matched growth rate (1.4 ± 0.1 mm/yr, p < 0.0001). Despite improving the inflammatory activity as seen on MRI, repetitive CSI to the TMJ does not reach the treatment goals to prevent progressive osseous deformation and to normalize mandibular ramus growth in children with juvenile idiopathic arthritis.

Gene, environment, microbiome and mucosal immune tolerance in rheumatoid arthritis.

RA is a complex multifactorial chronic disease that transitions through several stages. Multiple studies now support that there is a prolonged phase in early RA development during which there is serum elevation of RA-related autoantibodies including RF and ACPAs in the absence of clinically evident synovitis. This suggests that RA pathogenesis might originate in an extra-articular location, which we hypothesize is a mucosal site. In discussing this hypothesis, we will present herein the current understanding of mucosal immunology, including a discussion about the generation of autoimmune responses at these surfaces. We will also examine how other factors such as genes, microbes and other environmental toxins (including tobacco smoke) could influence the triggering of autoimmunity at mucosal sites and eventually systemic organ disease. We will also propose a research agenda to improve our understanding of the role of mucosal inflammation in the development of RA.

Caracterización imagenológica de la sinovitis vellonodular pigmentada y el tumor de células gigantes de la vaina sinovial

PurposeTo show the resonance magnetic imaging (MRI) findings of pigmented villonodular synovitis (PVNS) and giant cell tumor of the tendon sheath (PVNTS), entities with similar histology but differences in clinical and some radiological manifestations. Materials and methodsWe studied 25 cases with histologically benign synovial proliferation in intra and extra-articular location of the extremities. It highlighted with a 1.5T MRI unit the different types of images presentation. The results were analyzed and compared with the literature. ResultsMRI displayed very specific imaging features in all patients. However, we were able to distinguish 4 main patterns of presentation depending on the morphology, location of the lesion and radiological differential. These were: as dominant presentation, pigmented villonodular synovitis localized form (n=10); pigmented villonodular synovitis bursal form (n=2); pigmented villonodular synovitis focal (n=5); and pigmented villonodular synovitis diffuse (n=8). ConclusionBoth pigmented villonodular synovitis as well as giant cell tumor of the tendon sheath are considered similar from the point of view of the histological findings. MRI was useful to objectify both radiological features in common, such as the differential, which along with the location, allow us to classify patterns into 4 individual presentations. This recognition involves adequate radiological evaluation and is important for optimal management.

A2.2 Uveitis is not associated with cardiovascular disease risk factors in patients with ankylosing spondylitis

Background and ObjectivesAnkylosing spondylitis (AS) is a chronic, autoimmune, systemic, inflammatory disease. Recently, a link has been established between autoimmune inflammatory diseases, incl. AS, and the risk of developing cardiovascular...

Evaluation of Contrast Extravasation as a Diagnostic Criterion in the Evaluation of Arthroscopically Proven HAGL/pHAGL Lesions.

Purpose. The validity of preoperative MRI in diagnosing HAGL lesions is debated. Various investigations have produced mixed results with regard to the utility of MRI. The purpose of this investigation is to apply a novel method of diagnosing HAGL/pHAGL lesions by looking at contrast extravasation and to evaluate the reliability of such extravasation of contrast into an extra-articular space as a sign of HAGL/pHAGL lesion. Methods. We utilized specific criteria to define contrast extravasation. We evaluated these criteria in 12 patients with arthroscopically proven HAGL/pHAGL lesion. We also evaluated these criteria in a control group. Results. Contrast extravasation occurred in over 83% of arthroscopically positive cases. Contrast extravasation as a diagnostic criterion in the evaluation of HAGL/pHAGL lesions demonstrated a high interobserver degree of agreement. Conclusions. In conclusion, extra-articular contrast extravasation may serve as a valid and reliable sign of HAGL and pHAGL lesions, provided stringent criteria are maintained to assure that the contrast lies in an extra-articular location. In cases where extravasation is not present, the “J” sign, though nonspecific, may be the only evidence of subtle HAGL and pHAGL lesions. Level of Evidence. Level IV, Retrospective Case-Control series.