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Christian W A Pfirrmann

Christian W A Pfirrmann
Zurich, Switzerland

MD, MBA

About

379
Publications
131,077
Reads
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18,161
Citations
Additional affiliations
August 2015 - present
University of Zurich
Position
  • Professor ad Personam, Extraordinarius, Musculoskeletal Radiology
January 2000 - December 2000
University of California, San Diego
Position
  • Research Associate

Publications

Publications (379)
Article
Purpose To investigate the predictive value of talar head edema (THE) in acute ankle sprain for the presence of concomitant ligament injuries. Methods This retrospective study was approved by the ethics committee and informed consent was obtained. One hundred patients (mean age: 37 years ± 14 [standard deviation], range 13–77 years) with MRI of th...
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Objective To compare computer-based 3D-analysis for quantification of the femorotibial joint space width (JSW) using weight-bearing cone beam CT(WB-CT), non-weight-bearing multi-detector CT (NWB-CT), and weight-bearing conventional radiographs (WB-XR). Design Twenty-six participants prospectively underwent NWB-CT, WB-CT, and WB-XR of the knee. For...
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Purpose To evaluate the MRI anatomy of the scapho-trapezial-trapezoidal (STT) ligament complex in asymptomatic and symptomatic individuals. Material and methods In this retrospective study, STT ligament complex of 42 (male 69%, median age 37.5 years) asymptomatic ( n = 25) and symptomatic ( n = 17) (defined as pain described over the STT joint) in...
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Objectives: To assess the value of the divergence of toes on conventional radiographs of the foot for diagnosing Morton's neuroma. Methods: This retrospective case-control study was approved by the local ethics committee. In 100 patients with MRI-proven Morton's neuroma 2/3 or 3/4 (study group) and 100 patients without (control group), conventio...
Article
Background: Ischiofemoral impingement (IFI) is a known complication after total hip arthroplasty (THA). Purpose: To assess if increased postoperative (FA) is associated with magnetic resonance imaging (MRI) findings of IFI. Material and methods: In 221 patients with THA, two independent readers measured FA, ischiofemoral space (IFS), quadratus...
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Objectives To test the diagnostic accuracy of a 3D dual-echo steady-state (DESS) sequence at 7-T MRI regarding the detection of chondral calcific deposits of the knee in comparison to 3-T MRI, using CT as cross-sectional imaging reference standard. Methods CT and 7-T MRI (DESS) of knee joints in 42 patients with radiographically known chondrocalci...
Chapter
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Glenohumeral instability is the inability to keep the humeral head centered in the glenoid fossa. Glenohumeral instability can be classified according to etiology and direction of instability. The glenoid labrum, the glenohumeral ligaments, and the bony structures contribute to the stability glenohumeral joint and need to be addressed with imaging....
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Objectives To compare ultra-low-dose CT (ULD-CT) of the osseous pelvis with tin filtration to standard clinical CT (CT), and to assess the quality of computed virtual pelvic radiographs (VRs). Methods CT protocols were optimized in a phantom and three pelvic cadavers. Thirty prospectively included patients received both standard CT (automated tube...
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Objective To evaluate the prevalence, morphology, and clinical significance of a repeatedly observed yet not examined circumscript osseous defect at the anteroinferior aspect of the femoral head, termed femoral head defect. Materials and methods Retrospective study with approval of the institutional review board. There was informed consent by all...
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Objective To investigate long-term effects of pregnancy/childbirth on bone marrow edema (BME) and subchondral sclerosis of sacroiliac joints (SIJ) in comparison to MRI changes caused by spondyloarthritis (SpA) and assess the influence of birth method and number of children on SIJ-MRI changes. Materials and methods This is a retrospective cohort st...
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Background: Ultrasound (US) images are currently displayed on monitors, and their understanding needs good orientation skills. Direct overlay of US images onto the according anatomy is possible with augmented reality (AR) technologies. Our purpose was to explore the performance of US-guided needle placement with and without AR in situ US viewing....
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Objective To prospectively assess the evolution of postoperative MRI findings in asymptomatic patients after total hip arthroplasty (THA) over 24 months (mo). Methods This prospective cohort study included 9 asymptomatic patients (56.7 ± 15.0 years) after THA. Metal artifact–reduced 1.5-T MRI was performed at 3, 6, 12, and 24 mo after surgery. The...
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Objective To develop a new magnetic resonance imaging(MRI) scoring system for evaluation of active Charcot foot and to correlate the score with a duration of off-loading treatment ≥ 90 days.Methods An outpatient clinic database was searched retrospectively for MRIs of patients with active Charcot foot who completed off-loading treatment. Images wer...
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Objective In total hip arthroplasty (THA), surgeons attempt to achieve a physiological antetorsion. However, postoperative antetorsion of the femoral stem is known to show large variabilities. The purpose of this study was to assess whether postoperative antetorsion is influenced by stem design or cementation.Materials and methodsThis retrospective...
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Members of the International Skeletal Society compiled a glossary of terms for musculoskeletal radiology. The authors also represent national radiology or pathology societies in Asia, Australia, Europe, and the USA. We provide brief descriptions of musculoskeletal structures, disease processes, and syndromes and address their imaging features. Give...
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The article "Deep convolutional neural network-based detection of meniscus tears: comparison with radiologists and surgery as standard of reference.
Article
Background MRI with metal artifact reduction has gained importance in assessment of pain with total hip arthroplasty (THA). However, its role in diagnosis of periprosthetic joint infection (PJI) has not been well defined. Purpose To evaluate findings of PJI after THA and to determine the diagnostic performance of 1.5-T MRI with metal artifact reduc...
Article
Purpose To evaluate the diagnostic potential of MRI in patients with suspected CRPS (complex regional pain syndrome). Method A retrospective health-record search was conducted for patients with suspected CRPS (foot). Fifty patients with initially suspected CRPS were included (37 females (51 ± 13 years) and 13 males (44 ± 15 years)). All patients u...
Article
Purpose To evaluate 3D-printed anatomic models of the distal femur and patella for diagnosis and classification of patellofemoral dysplasia in comparison to conventional radiographs (CR) and CT. Method Following local ethics committee approval, CT-datasets of 50 patients were segmented and 3D-anatomic models of the distal femur and patella were pr...
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Objective To clinically validate a fully automated deep convolutional neural network (DCNN) for detection of surgically proven meniscus tears.Materials and methodsOne hundred consecutive patients were retrospectively included, who underwent knee MRI and knee arthroscopy in our institution. All MRI were evaluated for medial and lateral meniscus tear...
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Objectives: The aim of this study was to clinically validate a Deep Convolutional Neural Network (DCNN) for the detection of surgically proven anterior cruciate ligament (ACL) tears in a large patient cohort and to analyze the effect of magnetic resonance examinations from different institutions, varying protocols, and field strengths. Materials...
Article
Objectives: To investigate sex-specific differences in hip muscle strength asymmetries, and associations between hip abductor and flexor strength asymmetries, hip morphology and symptoms in patients with femoroacetabular impingement syndrome (FAIS). Design: Cross-sectional study. Setting: Clinical setting. Participants: Thirty-four patients...
Article
Objectives To investigate the value of extensive perilesional muscle edema for the differentiation between myositis ossificans (MO) and malignant intramuscular soft tissue tumors on MRI. Materials and methods Two blinded readers analyzed MR examinations of 90 consecutive patients with intramuscular soft tissue masses (group 1: MO, n = 20; group 2:...
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Objective To determine if MRI findings prior to intra articular corticosteroid hip infiltration are related to treatment outcomes. Methods This prospective outcome study with retrospective MRI evaluation includes 100 consecutive patients with MRI within 6 months before a therapeutic intra articular hip injection. Labrum, bone marrow, acetabular an...
Article
Objectives: To assess the spectrum of periprosthetic MRI findings after primary total hip arthroplasty (THA). Methods: This multi-center cohort study analyzed 31 asymptomatic patients (65.7 ± 12.7 years) and 27 symptomatic patients (62.3 ± 11.9 years) between 6 months and 2 years after THA. 1.5-T MRI was performed using Compressed Sensing SEMAC...
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Abstract Charcot foot refers to an inflammatory pedal disease based on polyneuropathy; the detailed pathomechanism of the disease is still unclear. Since the most common cause of polyneuropathy in industrialized countries is diabetes mellitus, the prevalence in this risk group is very high, up to 35%. Patients with Charcot foot typically present in...
Article
The purpose of this work was to quantify muscular perfusion patterns of back muscles after exercise in patients with adolescent idiopathic scoliosis (AIS) using intravoxel incoherent motion (IVIM) MR perfusion imaging. The paraspinal muscles of eight patients with AIS (Cobb angle 35 ± 10°, range [25‐47°]) and nine healthy volunteers were scanned wi...
Article
Background The study describes the difference of pain reduction in interlaminar and transforaminal injections. Purpose To compare treatment outcomes after interlaminar versus transforaminal epidural steroid injections in patients with disc herniations at the level L3/4–L5/S1 and analyze associated magnetic resonance imaging (MRI) findings. Materi...
Article
Background: The distribution of energy use among different lower limb muscles during walking and running is not well understood. Local blood flow within skeletal muscle tissue depends on its metabolic activity during activation. The non-invasive magnetic resonance microvascular perfusion method Intravoxel Incoherent Motion (IVIM) is able to quanti...
Article
OBJECTIVE. The anchoring of the medial meniscus is consistent, whereas the attachment of the lateral meniscus is variable. On routine MRI examinations, we analyzed the prevalence of a distinct fibrous connection between the anterolateral aspect of the lateral meniscus and the iliotibial band-which we have termed the "accessory iliotibial band-menis...
Article
Objectives This study was conducted in order to determine the predictive value of MR arthrography findings for pain relief after glenohumeral corticosteroid injection. Methods This study prospectively enrolled 212 patients (mean age 51.4 years; range 15–90) who underwent fluoroscopy-guided glenohumeral corticosteroid injection. All patients receiv...
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Background: Autologous matrix-induced chondrogenesis (AMIC) has become an interesting treatment option for osteochondral lesions of the talus (OLTs) with promising clinical short- to midterm results. Purpose: To investigate the clinical and radiological outcome of the AMIC procedure for OLTs, extending the follow-up to 8 years. Study design: C...
Article
Objectives To evaluate the feasibility of 2D and 3D acetabular coverage assessments based on low-dose biplanar radiographs (BPR) in comparison with CT, and to demonstrate the influence of weight-bearing position (WBP) on anterior and posterior acetabular coverages. Methods Fifty patients (21 females, 29 males) underwent standing BPR and supine CT...
Article
Purpose: To compare changes in the pubic symphysis between women with vaginal delivery and women with caesarean sections within the first postpartum week. Materials and methods: After institutional review board approval 30 healthy women were prospectively examined with MRI (transverse STIR-sequence) three days after delivery. 17 women with vagin...
Article
Purpose To compare the radiation exposure for participants and interventionalists as well as participant outcomes between fluoroscopy-guided versus CT-guided lumbar spinal injections. Materials and Methods This prospective, nonrandomized observational study included 1446 participants (mean age, 60.6 years; range, 18-91 years) who received transfora...
Article
Objectives: The aim of this study was to quantitatively assess changes in collagen structure using MR T1- and T2*-mapping in a novel controlled ex vivo tendon model setup. Materials and methods: Twenty-four cadaveric bovine flexor tendons underwent MRI at 3 T before and after chemical modifications, representing mechanical degeneration and augme...
Article
Objective To test a 3D-hindfoot alignment (HA) measurement technique based on low-dose biplanar radiographs (BPRs) in a clinical setting and compare the results with 2D-HA measurements on long axial view radiographs (LARs). Materials and methods This prospective study was approved by the local institutional review board. HA measurements on 3D-BPR...
Article
Background In daily routine, pincer femoroacetabular impingement (FAI) findings are often seen without a clinical diagnosis of pincer FAI. Purpose To assess the presence of pincer FAI MRI findings in asymptomatic volunteers with negative impingement test versus patients with clinically confirmed FAI. Study Type Case–control study. Population Six...
Article
Objective: The objective of our study was to compare MRI findings in the sacroiliac joints of postpartum women (as a model of mechanical changes) and women with known axial spondyloarthritis (as an inflammatory model). Subjects and methods: For this prospective multicenter age-matched, case-control study, sacroiliac joint MRI examinations of 30...
Article
Objectives: The purpose of this study was to identify an optimal imaging protocol for metal artifact reduced magnetic resonance imaging by application of different imaging and postprocessing parameters in compressed sensing slice-encoding for metal artifact correction (CS-SEMAC) and to test it in patients with total hip arthroplasty (THA). Materi...
Article
Objective To investigate the responsiveness to exercise therapy of patients with femoroacetabular impingement syndrome (FAIS), and differences in hip function, strength and morphology between responders vs. non‐responders. Methods Patients with FAIS underwent 12 weeks of semi‐standardized and progressive exercise therapy. Good therapy outcome (res...
Article
Purpose To determine the diagnostic performance of MRI for helping to predict posterolateral knee instability in patients with acute anterior cruciate ligament (ACL) tear. Materials and Methods This retrospective cohort study was performed in a consecutive series of 162 patients (mean age, 32.8 years ± 10.0 [standard deviation]; 95 men [mean age, 3...
Poster
Autologous matrix-induced chondrogenesis (AMIC) has recently become an interesting treatment option for osteochondral lesions of the talus. This work shows that AMIC for osteochondral lesions of the talus leads to significant reduction of pain, recovery of ankle function and return to sports at a follow-up of 2 to 8 years. The moderate MRI findings...
Article
Case: A 38-year-old man presented with multifocal, partially confluent osteolytic lesions in the proximal dia-meta-epiphyseal region of the proximal aspect of the left tibia, which had been found incidentally when a radiograph was made after a rotational knee injury. When the results of a percutaneous core needle biopsy proved inconclusive, an ope...
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Category Ankle Introduction/Purpose Autologous matrix-induced chondrogenesis (AMIC) has recently become an interesting treatment option for osteochondral lesions of the talus since it combines safety and efficacy with overcoming several drawbacks of other surgical techniques. With AMIC, donor side morbidity of osteochondral autografts is eliminate...
Article
Full-text available
Background: Anatomical landmarks for templating of total hip arthroplasty (THA) that are visible both during surgery and on radiographs are rare. If surgery is performed through a direct anterior approach the external obturator tendon (EO) is consistently visible. To use this point as a reference the exact position and dimensions of the footprint...
Article
Objective: The objective of our study was to evaluate a novel measurement technique for assessing the supra- and infratrochanteric components of femoral torsion, establish reference values in healthy volunteers, and compare supra- and infratrochanteric torsion angles in patients with hip dysplasia and patients with femoroacetabular impingement (FA...
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Objectives: The aim of this study was to assess feasibility and accuracy of augmented reality-guided lumbar facet joint injections. Materials and methods: A spine phantom completely embedded in hardened opaque agar with 3 ring markers was built. A 3-dimensional model of the phantom was uploaded to an augmented reality headset (Microsoft HoloLens...
Article
Objectives: The aim of this study was to assess the interreader agreement and diagnostic accuracy of morphologic magnetic resonance imaging (MRI) analysis and quantitative MRI-based texture analysis (TA) for grading of cartilaginous bone tumors. Materials and methods: This retrospective study was approved by our local ethics committee. Magnetic...
Article
Study Design Cross-sectional study. Background Visual rating of movement pattern in patients with femoroacetabular impingement (FAI) syndrome is of interest because poor control of dynamic hip motion is frequently noted. Objectives To evaluate intra- and inter-rater agreement among physical therapists with different clinical experience, in performi...
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Full-text available
Objective: To compare the prevalence of vitamin D insufficiency between radiologists and a control group of non-radiologists. Materials and methods: This prospective cross-sectional study was conducted at the Swiss Congress of Radiology in May of 2016. Attendees (radiologists and non-radiologists) were asked to give a venous blood sample to meas...
Article
Background: Anatomic findings on MRI scans of the shoulder likely affect patients differently based on their physical demands and fitness levels. The natural history of these anatomic findings once professional overhead athletes retire remains unclear. A better understanding of what happens with these findings after retirement may influence how we...
Article
Objective To describe the frequency of inflammatory-like findings on MR imaging in asymptomatic volunteers and compare them with patients with known rheumatoid arthritis and psoriatic arthritis. Materials and methodsMR images of fingers in 42 asymptomatic volunteers and 33 patients with rheumatoid/psoriatic arthritis were analyzed. The Outcome Meas...
Article
It is almost 20 years since the concept of femoroacetabular impingement (FAI) was introduced, and by now a large number of orthopaedic surgeons, sports physicians, and radiologists have implemented this concept in clinical practice, as is evident in the steady rise in the number of patients diagnosed and treated for FAI. However, this trend has bee...
Article
Purpose: We set out to compare outcomes in CT-guided lumbar transforaminal nerve root block patients receiving either particulate or non-particulate corticosteroids. Materials and methods: This was a retrospective comparative effectiveness outcomes study on two cohorts of lumbar radiculopathy patients. 321 received particulate and 173 non-partic...
Article
Objective To investigate the different morphologic types of the fovea capitis femoris and the spectrum of osseous spurs/osteophytes of the fovea in asymptomatic volunteers and patients with hip osteoarthritis. Material and methodsSixty-five patients (mean age 63.6 years) with radiographically confirmed osteoarthritis of the hip and 59 asymptomatic...
Article
Introduction To be able to predict which patients are more likely to have a positive treatment outcome, the purpose of this study is 1: To compare outcomes after intra-articular corticosteroid knee injections with the Kellgren and Lawrence (KL) 5 and 3 grading systems for knee osteoarthritis, the Osteoarthritis Research Society International (OARSI...
Article
Objective Aim of this study was to evaluate the flexion-adduction-internal rotation (FADIR) test accuracy for screening cam and pincer morphology in youth male ice hockey players without diagnosed hip disorders. Design Cross-sectional study. Methods Seventy-four ice hockey players with a mean age of 16 years (range: 13 to 20 years) were assessed...
Article
Objective: The purpose of this article is to determine the osseous morphology of snapping scapulae on CT images. Materials and methods: Retrospectively, 2D and 3D CT images of the scapulae of 35 patients with snapping scapula were compared with 35 age-matched control group subjects. Two observers analyzed the following parameters: presence of th...
Article
Objective: To assess whether the use of cartilaginous contours at the femoral condyles instead of bony contours significantly changes femoral torsion measurements in children. Materials and methods: Femoral torsion was measured in 32 girls (mean age 10.1 years±2.3 standard deviation) and 42 boys (10.9 years±2.5) on axial magnetic resonance (MR)...
Chapter
The common hamstring tendon is comprised of biceps femoris (long head), semitendinosus and semimembranosus [1]. At the ischial attachment site, semitendinosus and biceps femoris (BF-ST) form a conjoined tendon with a common osseous origin from the ischium. The semimembranosus (SM) tendon originates separately, contiguous with the conjoined tendon.
Article
Introduction: Based on U.S. Food and Drug Administration warnings, this hospital switched from using particulate to nonparticulate corticosteroids for lumbar nerve root injections. We set out to compare outcomes in lumbar nerve root block patients receiving either particulate or nonparticulate corticosteroids. Materials and Methods: This was a comp...