Ultra-long-term results of the Chiari pelvic osteotomy in hip dysplasia patients: a minimum of thirty-five years follow-up.

PURPOSE: The Chiari pelvic osteotomy was the first surgical procedure to address hip dysplasia by changing the position of the acetabulum by medialization, thus creating a bony roof and improving biomechanical conditions. The aim of this retrospective cohort study was to report on the very long-term results of this technique. METHODS: Out of a consecutive series of 1536 hips, 504 in 405 patients were available for follow-up. The patients were assessed by physical and radiological examination. A Kaplan-Meier survival analysis with total hip arthroplasty as an endpoint was performed and stratified for age groups, pre-operative diagnosis, sex and osteoarthritis stage. RESULTS: The average follow-up was 36 ± 8.1 years (range, 35.2 to 54). The average pain level on the Visual Analogue Scale was 2.9 ± 2.6 (range 0 to 8.7). The average Harris Hip Score was 80.2 ± 17.4 (range 17.4 to 100). Correction of dysplasia was effective and remained stable over time. Osteoarthritis significantly increased over time with 53% Tönnis grade 3 at follow-up. The cumulative survivorship was 79.8% (95% confidence interval (CI), 76.1-83.2%) at 20 years, 57.1% (95% CI, 52.8-61.8%) at 30 years and 35% (95% CI, 30.3-40.3%) at 40 years. Young age, male sex and low osteoarthritis grade were positive prognostic factors. CONCLUSIONS: Although the Chiari pelvic osteotomy is considered a salvage procedure nowadays, it achieved excellent long-term results even in indications, which would be treated differently today. Young patients without osteoarthritis had the best outcome.

Long-Term Results after Chiari Pelvic Osteotomy in the Skeletally Immature and the Role of the Anti-Chiari Effect.

Several authors observed a loss of correction after performing Chiari pelvic osteotomy (CPO) in young patients. Hence, the aim of this study was to answer two questions: (1) Does the Chiari pelvic osteotomy affect the development of the acetabulum in skeletally immature patients in the long term? (2) Is there any evidence of the previously described "Anti-Chiari" effect after a mean follow-up of 36 years? Data from 21 patients (27 hips) undergoing CPO before the age of 16 years were clinically assessed, and the evolution of radiological parameters over time was analyzed. The mean age at CPO was 11.2 years (±3; 4.4-15.7). The 20- and 30-year survival rates of the CPO were 100% and 92.6%, respectively. Mean postoperative medialization was 54% (±18; 23-99). The average osteotomy angle was 11° (±7; 2-28). No significant changes were found for the center-edge angle (CEA) and acetabular index (AI) over time; the angle of Idelberger and Frank (ACM) almost reached normal values at follow-up (FU); for the acetabular-head index (AHI), a slight shift toward the initial situation could be detected. The morphology of the acetabulum remained unchanged over time. The "Anti-Chiari effect" seems to be primarily caused by insufficient coverage of the femoral head rather than damage to the apophysis due to surgery.

Total Hip Arthroplasty after Previous Chiari Pelvic Osteotomy-A Retrospective Study of 301 Dysplastic Hips.

BACKGROUND: Controversy exists whether previous pelvic osteotomies have negative effects on total hip arthroplasty (THA). This study evaluates the implant survival and patient-reported outcomes of THA after previous Chiari pelvic osteotomy (CPO). METHODS: Data on 301 THAs after CPO were collected through clinical and radiological follow-up examinations and telephone interviews. The Kaplan-Meier survivorship analysis depicts implant survival. RESULTS: Of this consecutive series of 1536 CPOs, follow-up was completed in 405 patients with 504 CPOs after a mean time of 36 years (±8; range, 22-54 years). At follow-up, 301 hips (60%) had already undergone THA. The overall survival of THA with revision as an end point after 10, 20, and 25 years was 93%, 76%, and 68%, respectively. The revision rate was 12%. The average period between THA and revision surgery was 9.6 years (±6.1; 4 months-25.4 years). The patient's age at revision was 57.9 years (±10; 33.2-78.5 years). Aseptic loosening was the most common of the known reasons for revision surgery. CONCLUSION: This retrospective study supports the hypothesis that prior CPO does not compromise the prerequisites for successful THA at a later stage. Survival rates of the implanted prosthesis are comparable to primary implanted hips, as overall survival was 93% after 10 years.

Endoscopy and MR enteroclysis: equivalent tools in predicting clinical recurrence in patients with Crohn's disease after ileocolic resection.

BACKGROUND: Ileocolonoscopy poses the gold standard in the evaluation of postoperative recurrence of Crohn's disease (CD) at the site of ileocolonic anastomosis. Magnetic resonance enteroclysis (MRE) on the other hand is a promising technique for small bowel imaging. The aim was to compare MRE and ileocolonoscopy for predicting clinical recurrence in CD patients who have undergone ileocolonic resection. METHODS: We included 29 patients in the study. The median time since index operation was 35 months and between ileocolonoscopy and MRE was 3 days. Patients were followed up for a maximum of 2 years unless clinical recurrence occurred earlier. Endoscopic findings were evaluated on a 5-grade scale (i0-i4), whereas MRE findings on the neoterminal ileum and anastomosis were assessed according to a previously validated 4-grade scale MR score (MR0-MR3). RESULTS: By classifying patients into subgroups of endoscopic severity of postoperative recurrence using as a threshold an endoscopic score of i3, we found that 10% of patients in the i0 to i2 group had a clinical recurrence during the 2-year follow-up period as compared to 52.6% of subjects with i3 to i4 (P = 0.043). The corresponding clinical exacerbation rates in the subgroups based on MRE severity assessment were 12.5% for MR0 to MR1 and 50% for MR2 to MR3 (P = 0.09). CONCLUSIONS: Our data suggest that colonoscopy and MR enteroclysis are of similar value to predict the risk of clinical recurrence in postoperative patients with Crohn's disease.

Automatic assessment of the knee alignment angle on full-limb radiographs.

In this study a fully automatic assessment of the knee alignment angles in full-limb radiographs was developed and compared to manual standard of reference measurements in a prospective manner. The data consisted of 28 knees which were gathered from total-leg radiographs of 15 patients (12 males and 3 females with a mean age of 29.4+/-6.9 years) consecutively. For statistical evaluation, a leave-one-out cross-validation was performed. The pattern recognition and consequently the fully automatic assessment were successful in all patients. The automatically measured angles highly correlated with the standard of reference (r=0.989). The mean absolute difference was 0.578 degrees (95% CI: 0.399-0.757 degrees ). 82% of the angles differed less than 1 degrees from the standard of reference, 46% differed less than 0.5 degrees and 31% differed less than 0.2 degrees . The automatic method showed a high agreement between repeated measurements (+0.515 degrees to -0.429 degrees ). The automatic assessment of alignment angles in full-limb radiographs were equal to the manual assessment. No measurement related user interaction was necessary to achieve results.

CT-MR image data fusion for computer-assisted navigated surgery of orbital tumors.

PURPOSE: To demonstrate the value of multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) in the preoperative assessment of orbital tumors, and to present, particularly, CT and MR image data fusion for surgical planning and performance in computer-assisted navigated surgery of orbital tumors. MATERIALS AND METHODS: In this retrospective case series, 10 patients with orbital tumors and associated complaints underwent MDCT and MRI of the orbit. MDCT was performed at high resolution, with a bone window level setting in the axial plane. MRI was performed with an axial 3D T1-weighted (w) gradient-echo (GE) contrast-enhanced sequence, in addition to a standard MRI protocol. First, MDCT and MR images were used to diagnose tumorous lesions compared to histology as a standard of reference. Then, the image data sets from CT and 3D T1-w GE sequences were merged on a workstation to create CT-MR fusion images that were used for interventional planning and intraoperative image guidance. The intraoperative accuracy of the navigation unit was measured, defined as the deviation between the same landmark in the navigation image and the patient. Furthermore, the clinical preoperative status was compared to the patients' postoperative outcome. RESULTS: Radiological and histological diagnosis, which revealed 7 benign and 3 malignant tumors, were concordant in 7 of 10 cases (70%). The CT-MR fusion images supported the surgeon in the preoperative planning and improved the surgical performance. The mean intraoperative accuracy of the navigation unit was 1.35mm. Postoperatively, orbital complaints showed complete regression in 6 cases, were ameliorated notably in 3 cases, and remained unchanged in 1 case. CONCLUSION: CT and MRI are essential for the preoperative assessment of orbital tumors. CT-MR image data fusion is an accurate tool for planning the correct surgical procedure, and can improve surgical results in computer-assisted navigated surgery of orbital tumors.

Diagnostic imaging in Merkel cell carcinoma: lessons to learn from 16 cases with correlation of sonography, CT, MRI and PET.

OBJECTIVE: The authors report imaging findings in a series of 16 patients with MCC, a rare tumour which is often managed primarily by a dermatologist. To our knowledge, no equivalent series of MCC has been described in the nuclear medicine literature. MATERIAL AND METHODS: In this IRB-approved retrospective noncomparative case series 16 patients with biopsy-proven Merkel cell carcinoma were included between January 1999 and October 2007. Twenty-nine whole body PET scans (18F-FDG n=24, 18F-FDOPA n=5) in 16 patients were retrospectively reviewed with regard to tracer uptake in six anatomical sites per patient. For 127/144 of FDG-PET evaluated regions and 68/144 of regions depicted by conventional imaging methods, a valid standard of reference could be obtained. A combined standard of reference was applied, which consisted of histopathology (lymphadenectomy or biopsy) or clinical or radiological follow-up for at least 12 months. RESULTS: the mean FDG uptake over the clinicopatholigical verified FDG avid areas was 4.7 SUV (1.5-9.9 SUV). The region based assessment of diagnostic value, in consideration of the standard of reference, resulted in a sensitivity of 85.7% and a specificity of 96.2% of FDG-PET (n=127) and in a combined sensitivity of 95.5% and a specificity of 89.1% for morphological imaging methods (n=68). Differences between methods did not reach statistical significance (p=1.00, p=0.18). CONCLUSIONS: FDG-PET is a highly useful whole body staging method of comparable value compared to conventional imaging methods with restricted field of view. The lessons learned from case series are discussed.

Multiple computer-based methods of measuring joint space width can discriminate between treatment arms in the COBRA trial -- Update of an ongoing OMERACT project.

Previously reported data on 5 computer-based programs for measurement of joint space width focusing on discriminating ability and reproducibility are updated, showing new data. Four of 5 different programs for measuring joint space width were more discriminating than observer scoring for change in narrowing in the 12 months interval. Three of 4 programs were more discriminating than observer scoring for the 0-18 month interval. The program that failed to discriminate in the 0-12 month interval was not the same program that failed in the 0-18 month interval. The committee agreed at an interim meeting in November 2007 that an important goal for computer-based measurement programs is a 90% success rate in making measurements of joint pairs in followup studies. This means that the same joint must be measured in images of both timepoints in order to assess change over time in serial radiographs. None of the programs met this 90% threshold, but 3 programs achieved 85%-90% success rate. Intraclass correlation coefficients for assessing change in joint space width in individual joints were 0.98 or 0.99 for 4 programs. The smallest detectable change was < 0.2 mm for 4 of the 5 programs, representing 29%-36% of the change within the 99th percentile of measurements.

Long-term experience with Chiari's osteotomy.

UNLABELLED: Fifty-six years after the introduction of Chiari's pelvic osteotomy, we report the long-term function scores and radiographic grade of osteoarthritis in 66 patients with 80 pelvic osteotomies with a minimum followup time of 27 years (average, 32 years; range, 27-48 years). These 66 patients were those who could be contacted and who returned for a followup visit from among 450 patients operated between 1961 and 1981. Thirty-two hips (40%) in 28 patients had undergone a total joint arthroplasty after an average 26 years (range, 13-41 years). Forty-eight hips in 41 patients (60%) were not replaced, their Harris hip score being a median of 82 points (range, 37-100 points). For the 22 patients for whom we had complete radiographs the average preoperative CE angle was 11.6 degrees, 48.6 degrees (range, 31 degrees-82.8 degrees) immediately postoperatively, and 41.6 degrees (range, 13.7 degrees-90 degrees) at last followup . Despite a functional hip score in most patients retaining their native hip, the degree of osteoarthritis progressed at last followup. We observed a similar mean age at the time of osteotomy in patients converted to total hip arthroplasty and those retaining their native hip. Age at time of surgery was inversely correlated (r = -0.78) with the interval between the osteotomy and THA. In this select patient group we found good functional outcome in patients who underwent Chiari pelvic osteotomy, with a conversion rate of 40% to total hip arthroplasty a mean of 32 years after the procedure. LEVEL OF EVIDENCE: Level IV, case series. See Guidelines for Authors for a complete description of levels of evidence.

Assessement of rheumatic diseases with computational radiology: current status and future potential.

In recent years, several computational image analysis methods to assess disease progression in rheumatic diseases were presented. This review article explains the basics of these methods as well as their potential application in rheumatic disease monitoring, it covers radiography, sonography as well as magnetic resonance imaging in quantitative analysis frameworks.

Three-dimensional fracture visualisation of multidetector CT of the skull base in trauma patients: comparison of three reconstruction algorithms.

The purpose of this study was to retrospectively assess the detection rate of skull-base fractures for three different three-dimensional (3D) reconstruction methods of cranial CT examinations in trauma patients. A total of 130 cranial CT examinations of patients with previous head trauma were subjected to 3D reconstruction of the skull base, using solid (SVR) and transparent (TVR) volume-rendering technique and maximum intensity projection (MIP). Three radiologists independently evaluated all reconstructions as well as standard high-resolution multiplanar reformations (HR-MPRs). Mean fracture detection rates for all readers reading rotating reconstructions were 39, 36, 61 and 64% for SVR, TVR, MIP and HR-MPR respectively. Although not significantly different from HR-MPR with respect to sensitivity (P = 0.9), MIP visualised 18% of fractures that were not reported in HR-MPR. Because of the relatively low detection rate using HR-MPRs alone, we recommend reading MIP reconstructions in addition to the obligatory HR-MPRs to improve fracture detection.

Quantifying disease activity and damage by imaging in rheumatoid arthritis and osteoarthritis.

Traditional imaging, represented by radiographs, provides a very concise description of anatomical pathology of bony structures. Both degenerative and inflammatory joint diseases are characterized by progressive joint destruction, and valid, reproducible measures of disease impact are available. Much effort has been expended to develop scoring systems for joint destruction in both osteoarthritis and rheumatoid arthritis, and the most common internationally accepted semiobjective scores are presented. The anatomical pathology mirrors the past activity of the disease, and advanced imaging gives an impression of the actual disease processes, which subsequently lead to the damage. Such information is required to facilitate the development of efficient therapy against arthritis. Newer technology, exemplified by MRI and ultrasound Doppler, supplements images of structural change with functional data of ongoing disease activity. This chapter focuses on the possibilities for quantification of images in MRI and ultrasound, in which postcontrast enhancement and Doppler information, respectively, are of special interest for the evaluation of the inflammatory changes of arthritis. To save time and eliminate human bias, automation is mandatory. In ultrasound, semiautomatic evaluations are coming that allow for a real-time, reproducible estimate of disease activity. With MRI fully automated algorithms have been developed for processing of data of bony structures, cartilage, and soft tissue, and are currently being implemented into everyday clinical practice.

Automatic quantification of joint space narrowing and erosions in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic disease that affects and potentially destroys the joints of the appendicular skeleton. The precise and reproducible quantification of the progression of joint space narrowing and the erosive bone destructions caused by RA is crucial during treatment and in imaging biomarkers in clinical trials. Current manual scoring methods exhibit high interreader variability, even after intensive training, and thus, impede the efficient monitoring of the disease. We propose a fully automatic quantitative assessment of the radiographic changes that result from RA, to increase the accuracy, reproducibility, and speed of image interpretation. Initial joint location estimates are obtained by local linear mappings based on texture features. Bone contours are delineated by active shape models comprised of statistical models of bone shape and local texture. These models are refined by snakes which increase the accuracy and allow for a fitting of pathological deviations from the training population. The method then measures joint space widths and detects erosions on the bone contour. Joint space widths are measured with a coefficient of variation of 2%-7% for repeated measurements and erosion detection exhibits an area under the receiver operating characteristic (ROC) curve of 0.89. Model landmarks serve as a reference system along the contour. These landmarks enable the definition of joint regions and more specific follow-up monitoring. The automatic quantification allows for a remote analysis, relevant for multicenter clinical trials, and reduces the workload of clinical experts since parts of the process can be managed by nonexpert personnel.

SPECT/CT fusion imaging in radionuclide cisternography for localization of liquor leakage sites.

OBJECTIVE: We report our experience with radionuclide cisternography (RC) with 111In-diethylenthriamine penta-acetic acid (DTPA) using a computed tomography (CT) mounted hybrid gamma camera in patients with cerebrospinal liquor leakage. METHODS: SPECT/CT fusion imaging was performed in case of suspected tracer egress on planar or SPECT images in order to obtain a detailed correlation of the leakage site. RESULTS: Leakage was detected in all 3 patients. Using SPECT/CT, the extradural tracer accumulation could be correlated to an anatomical structure, which had not been possible by evaluation of the scintigraphic studies alone. CONCLUSION: Introducing SPECT/CT for radionuclide cisternography seems to be a valuable tool to facilitate the diagnosis of cerebrospinal liquor leakage.

Sinonasal imaging after Caldwell-Luc surgery: MDCT findings of an abandoned procedure in times of functional endoscopic sinus surgery.

BACKGROUND AND PURPOSE: Today, functional endoscopic sinus surgery (FESS) is performed in most of the patients with sinonasal inflammatory disease. The postoperative imaging findings of FESS in multidetector computed tomography (MDCT) considerably differ from those of historic Caldwell-Luc (CL) maxillary sinus surgery which is an uncommon procedure today. Thus, the postoperative CL imaging findings may lead to diagnostic confusion and misinterpretation. Therefore, this study explicitly presents the MDCT findings of post-CL patients which have not been described previously. METHODS: Twenty-eight patients with clinically suspected sinusitis and documented history of CL-procedure underwent 16 row MDCT (MDCT Mx8000 IDT Philips) with multiplanar reconstructions of the paranasal sinuses in the axial plane. The following parameters were used: 140kV, 50mAs; 16mmx0.75mm detector collimation; 1mm reconstructed slice thickness; 0.5mm increment. The studies were reconstructed with a bone algorithm (W3000/L600; 1mm slice thickness) in axial plane and coronal plane (3mm slice thickness). The images were retrospectively evaluated for the presence of normal surgery-related and pathological findings. RESULTS: Surgery-related imaging characteristics presented as follows: an anterior and a medial bony wall defect and sclerosis and sinus wall thickening were observed in all 28/28 cases (100%). Collaps of the sinus cavity was seen in 26/28 cases (92.9%). Furthermore, inflammatory disease of the operated sinus(es) was found in 23/28 cases (82.1%): 14/28 patients (50%) had inflammatory mucosal thickening of the operated sinus(es) as well as of other sinonasal cavities and 9/28 patients (32.1%) had inflammatory mucosal thickening limited to the operated sinus(es). A postoperative mucocele was depicted in 3/28 cases (10.7%). 2/28 patients (7.1%) showed neither maxillary nor other mucosal swelling. CONCLUSION: MDCT with multiplanar reconstructions is a precise method to evaluate post-CL patients and helps to differentiate normal surgery-related findings, which may mimic pathology, from real pathological findings.

Automated measurement of joint space width in small joints of patients with rheumatoid arthritis.

OBJECTIVE: Comparison of performances of 5 (semi)automated methods in measuring joint space width (JSW) in rheumatoid arthritis. METHODS: Change in JSW was determined by 5 measurement methods on 4 radiographs per patient from 107 patients included in the COBRA trial (comparing sulfasalazine alone or in combination with methotrexate and corticosteroids). For each method the number of patients with sufficient available results was assessed (efficiency). An independent repeated measurement was carried out on a random sample of 30 patients' baseline and 1-year radiographs, to evaluate within-method reliability of change scores. Discriminatory ability (DA) of the measurement methods (between the 2 treatment arms) was compared with the DA of the Sharp-van der Heijde score (SHS) and its 2 components (erosion and JSW scores). RESULTS: The overall success rate varied widely between methods. Applying the chosen threshold of a minimum of 50% available joints with a change score per patient resulted in a success rate > 92% in 4/5 methods. Repeatability of measurements was good for most methods (intraclass correlation coefficient > or = 0.80 in 4/5 methods). Almost all measurement methods in 3 followup periods (12/14) showed a lower mean loss of JSW in patients from the intensive treatment group, although this was rarely statistically significant, confirming the known difference in structural damage. JSW as measured by the (semi)automated systems often showed higher DA than the JSW score of the SHS, but was lower than the total SHS and erosion scores. CONCLUSION: Although efficiency of the methods should be improved further, results already show good reliability and encouraging DA of most methods. Optimal information may be obtained with a combination of scoring of erosions and (semi)automated measurement of JSW.

Anastomotic recurrence of Crohn's disease after ileocolic resection: comparison of MR enteroclysis with endoscopy.

The purpose of this study was to assess the accuracy of MR enteroclysis in patients with Crohn's disease recurrence after ileocolic resection and to establish an MR scoring sytem. MR enteroclysis and endoscopy were performed in 30 patients with suspected Crohn's disease recurrence after ileocolic resection. Findings were evaluated by three radiologists, using an MR score based on image quality, contrast enhancement, and mural and extramural bowel-wall changes: MR0 (no abnormal features), MR1 (minimal mucosal changes), MR2 (diffuse aphtoid ileitis, moderate recurrence), and MR3 (severe recurrence with trans- and extramural changes). The endoscopic Rutgeerts score defines changes at the ileum on a scale from I0 to I4. In 3/30 (10%) patients, evaluation was not possible. The mean overall image quality was rated as 1.7 (kappa 0.78). Comparing MR and Rutgeerts score, the mean observer agreement for the total score rating was 77.8% (kappa 0.67). When comparing only scores below or above MR2-the threshold indicative of the necessity of medical treatment-there was a total agreement of 95.1% (kappa 0.84). MR enteroclysis allows assessment of Crohn's disease recurrence after ileocolic resection. The MR score is reproducible and shows high agreement with the approved endoscopic Rutgeerts score.

Robust autonomous model learning from 2D and 3D data sets.

In this paper we propose a weakly supervised learning algorithm for appearance models based on the minimum description length (MDL) principle. From a set of training images or volumes depicting examples of an anatomical structure, correspondences for a set of landmarks are established by group-wise registration. The approach does not require any annotation. In contrast to existing methods no assumptions about the topology of the data are made, and the topology can change throughout the data set. Instead of a continuous representation of the volumes or images, only sparse finite sets of interest points are used to represent the examples during optimization. This enables the algorithm to efficiently use distinctive points, and to handle texture variations robustly. In contrast to standard elasticity based deformation constraints the MDL criterion accounts for systematic deformations typical for training sets stemming from medical image data. Experimental results are reported for five different 2D and 3D data sets.

Object localization based on Markov random fields and symmetry interest points.

We present an approach to detect anatomical structures by configurations of interest points, from a single example image. The representation of the configuration is based on Markov Random Fields, and the detection is performed in a single iteration by the MAX-SUM algorithm. Instead of sequentially matching pairs of interest points, the method takes the entire set of points, their local descriptors and the spatial configuration into account to find an optimal mapping of modeled object to target image. The image information is captured by symmetry-based interest points and local descriptors derived from Gradient Vector Flow. Experimental results are reported for two data-sets showing the applicability to complex medical data.

An automatic model-based system for joint space measurements on hand radiographs: initial experience.

This ethics committee-approved pilot study was performed with informed consent. A Web-based service that was developed for automated measurement of joint space and automatic analysis of radiographs was tested prospectively. A total of 160 metacarpophalangeal joint spaces were measured in 20 patients (average age, 48 years; age range, 18-89 years; 16 women) suspected of having rheumatoid arthritis or osteoarthritis. The technical success rate was 93%. The smallest detectable difference in repeated automatic joint space width measurements varied from 0.08 to 0.31 mm, and the coefficient of variation was 2%-7%. Compared with the reference standard (interactive segmentation of the joint space widths) measurements, results were within a mean error of 0.19-0.40 mm. The proposed Web-based service enables reproducible joint space measurements to be obtained in metacarpophalangeal joints with moderate erosive and osteophytic disease.