Hyaline fibromatosis of Hoffa's fat pad in a patient with a mild type of hyaline fibromatosis syndrome.

Hyaline fibromatosis syndrome (HFS) is a rare, homozygous, autosomal recessive disease, characterized by deposition of hyaline material in skin and other organs, resulting in esthetic problems, disability, and potential life-threatening complications. Most patients become clinically apparent in the first few years of life, and the disorder typically progresses with the appearance of new lesions. We describe a rare case of a 20-year-old patient with juvenile-onset mild HFS who presented with a history of progressive anterior knee pain. Detailed magnetic resonance (MR) imaging findings with histopathological correlation are presented of hyaline fibromatosis of Hoffa's fat pad, including differential diagnosis. The diagnosis of HFS is generally made on basis of clinical and histopathological findings. Imaging findings, however, may contribute to the correct diagnosis in patients who present with a less typical clinical course of HFS.

Standard MRI May Not Predict Specific Acute Anterior Cruciate Ligament Rupture Characteristics.

BACKGROUND: There has been renewed interest in the concept of anterior cruciate ligament (ACL) suture repair (ACLSR). Morphologic characteristics of the ruptured ACL remnant play a role in deciding whether a patient is eligible for ACLSR. However, no classification of these characteristics of ACL rupture on magnetic resonance imaging (MRI) scans has yet been compared with intraoperative findings in the context of ACLSR. PURPOSE: To investigate the value of using preoperative MRI to predict specific characteristics of acute complete ACL rupture. STUDY DESIGN: Cohort study (diagnostic); Level of evidence, 2. METHODS: A total of 25 patients were included. Two radiologists classified ACL rupture location and pattern on preoperative 1.5-T MRI scans with a standard sequence; the results were compared with the corresponding findings at arthroscopy conducted by a single surgeon. The agreement between the MRI and surgical findings was calculated using Cohen κ values. Furthermore, the reliability coefficients of the MRI classifications within and between radiologists were calculated. RESULTS: The agreement between MRI classification and arthroscopic findings for ACL rupture location was slight (Cohen κ, 0.016 [radiologist 1] and 0.087 [radiologist 2]), and for ACL rupture pattern, this was poor to slight (Cohen κ, <0 and 0.074). The intraobserver reliability of MRI classification for ACL rupture location was moderate for radiologist 1 and slight for radiologist 2 (Cohen κ, 0.526 and 0.061, respectively), and for ACL rupture pattern, this was slight for radiologist 1 and 2 (Cohen κ, 0.051 and 0.093, respectively). The interobserver reliability of MRI classification for ACL rupture location and pattern was slight between radiologists (Cohen κ, 0.172 and 0.040, respectively). CONCLUSION: In the current study, we found poor to slight agreement between MRI classification and arthroscopic findings of specific ACL rupture characteristics. In addition, the intra- and interobserver reliability for MRI classification of the ACL rupture characteristics was slight to moderate.

The diagnostic potential of low-field MRI in problematic total knee arthroplasties - a feasibility study.

PURPOSE: Low-field MRI, allowing imaging in supine and weight-bearing position, may be utilized as a non-invasive and affordable tool to differentiate between causes of dissatisfaction after TKA ('problematic TKA'). However, it remains unclear whether low-field MRI results in sufficient image quality with limited metal artefacts. Therefore, this feasibility study explored the diagnostic value of low-field MRI concerning pathologies associated with problematic TKA's' by comparing low-field MRI findings with CT and surgical findings. Secondly, differences in patellofemoral parameters between supine and weight-bearing low-field MRI were evaluated. METHODS: Eight patients with a problematic TKA were scanned using low-field MRI in weight-bearing and supine conditions. Six of these patients underwent revision surgery. Scans were analysed by a radiologist for pathologies associated with a problematic TKA. Additional patellofemoral and alignment parameters were measured by an imaging expert. MRI observations were compared to those obtained with CT, the diagnosis based on the clinical work-up, and findings during revision surgery. RESULTS: MRI observations of rotational malalignment, component loosening and patellofemoral arthrosis were comparable with the clinical diagnosis (six out of eight) and were confirmed during surgery (four out of six). All MRI observations were in line with CT findings (seven out of seven). Clinical diagnosis and surgical findings of collateral excessive laxity could not be confirmed with MRI (two out of eight). CONCLUSION: Low-field MRI shows comparable diagnostic value as CT and might be a future low cost and ionizing radiation free alternative. Differences between supine and weight-bearing MRI did not yield clinically relevant information. The study was approved by the Medical Research Ethics Committees of Twente (Netherlands Trial Register: Trial NL7009 (NTR7207). Registered 5 March 2018, https://www.trialregister.nl/trial/7009 ).

Metal artefacts severely hamper magnetic resonance imaging of the rotator cuff tendons after rotator cuff repair with titanium suture anchors.

BACKGROUND: The rate of retear after rotator cuff surgery is 17%. Magnetic resonance imaging (MRI) scans are used for confirmative diagnosis of retear. However, because of the presence of titanium suture anchors, metal artefacts on the MRI are common. The present study evaluated the diagnostic value of MRI after rotator cuff tendon surgery with respect to assessing the integrity as well as the degeneration and atrophy of the rotator cuff tendons when titanium anchors are in place. METHODS: Twenty patients who underwent revision surgery of the rotator cuff as a result of a clinically suspected retear between 2013 and 2015 were included. The MRI scans of these patients were retrospectively analyzed by four specialized shoulder surgeons and compared with intra-operative findings (gold standard). Sensitivity and interobserver agreement among the surgeons in assessing retears as well as the Goutallier and Warner classification were examined. RESULTS: In 36% (range 15% to 50%) of the pre-operative MRI scans, the observers could not review the rotator cuff tendons. When the rotator cuff tendons were assessable, a diagnostic accuracy with a mean sensitivity of 0.84 (0.70 to 1.0) across the surgeons was found, with poor interobserver agreement (kappa = 0.12). CONCLUSIONS: Metal artefacts prevented accurate diagnosis from MRI scans of rotator cuff retear in 36% of the patients studied.

Sagittal spinal profile and spinopelvic balance in parents of scoliotic children.

BACKGROUND CONTEXT: It is well known that spinal biomechanics and familial predisposition play an important role in the onset and evolution of idiopathic scoliosis. The relationship between the sagittal profile of the spine and spinal biomechanics has also been established in a number of studies. It has been suggested previously that a certain sagittal spinal configuration with implications for spinal rotational stiffness is inherited, thus providing a possible explanation for the well-known hereditary component in adolescent idiopathic scoliosis (AIS). PURPOSE: To test the hypothesis that the familial trend in AIS may be partially explained by the inheritance of a sagittal spinal profile, which has been shown to make the spine less resistant to rotatory decompensation. STUDY DESIGN: A prospective case controlled radiographic analysis of the sagittal profile of the spine and spinopelvic alignment. PATIENT SAMPLE: One hundred two parents of scoliotic children, compared with 102 age-matched controls (parents of nonscoliotic children). OUTCOME MEASURES: Physiologic measures: sagittal profile of the spine and spinopelvic alignment. METHODS: Freestanding lateral radiographs of 51 parent couples of girls with severe (Cobb angle >30°) progressive AIS (AIS group) and 102 age-matched controls (control group) were taken. Parents with manifest spinal deformities or spinal pathology of any kind were excluded based on history or spinal X-ray to avoid distorted sagittal images with unreliable measurements. Values were calculated for thoracic kyphosis (T4-T12), lumbar lordosis (L1-L5), spinal balance (sagittal plumb line of C7 and T4, T1-L5 sagittal spinal inclination, T9 sagittal offset), curvature parameters (expressed in the area under the curve [AUC]), and pelvic parameters (pelvic tilt, pelvic incidence, and sacral slope). In addition, the height, offset, and length of the posteriorly inclined spinal segment, inclination of each vertebra, and normalized sagittal spinal profile were calculated. Differences in spinopelvic alignment between fathers and mothers of both groups were analyzed. RESULTS: In the fathers of the AIS group, the plumb line of T4 was significantly less posteriorly positioned relative to the hip axis (79 mm vs. 92 mm; p=.009); the overall AUC and the lumbar AUC were significantly smaller (p=.002 and p=.008, respectively) as compared with the fathers in the control group. Vertebrae T11-L2 were significantly less backwardly inclined in the fathers of the AIS group (T11, L2: p<.05 and T12-L1: p<.01). An analysis of sagittal spinal profile showed a significantly flatter spine in the fathers of the AIS group (p=.01). No significant differences were observed in height, offset, and length of the backwardly inclined spinal segment. In the mothers of the AIS group, no statistically significant differences were observed in the spinopelvic parameters, spinal curvature, inclination of the vertebrae, and declive spinal segment parameters or sagittal spinal profile as compared with the mothers in the control group. CONCLUSIONS: The sagittal spinal profile of the fathers of scoliotic children was significantly flatter than the sagittal spinal profile of fathers of nonscoliotic children. No difference was found in the sagittal spinal profile of the mothers of scoliotic children as compared with mothers of nonscoliotic children. Although it is well known that scoliotic mothers have an increased risk of having a scoliotic offspring, this study indicates that fathers may possibly contribute as well through their sagittal spinal profile to the inheritance of idiopathic scoliosis.