Background Context: Pedicle screw loosening is common after spinal fusion and can be associated with pseudoarthrosis and pain. With suspicion of screw loosening on standard radiographs, CT is currently considered the advanced imaging modality of choice. MRI with new metal artifact reduction techniques holds potential to be sensitive in detection of screw loosening. The sensitivity and specificity of either of the imaging modalities are yet clear.
Purpose: To evaluate the sensitivity and specificity of three different image modalities (standard radiographs, CT, and MRI) for detection of pedicle screw loosening.
Study Design/setting: Cross-sectional diagnostic study.
Patient Sample: Forty-one patients (159 pedicle screws) undergoing revision surgeries after lumbar spinal fusion between August 2014 and April 2017 with preoperative radiographs, CT, and MRI with spinal metal artifact reduction (STIR WARP and TSE high bandwidth sequences).
Outcome Measures: Sensitivity and specificity in detection of screw loosening for each imaging modality.
Methods: Screw torque force was measured intraoperatively and compared with preoperative screw loosening signs such as peri-screw edema in MRI and peri-screw osteolysis in CT and radiographs. A torque force of less than 60 Ncm was used to define a screw as loosened.
Results: Sensitivity and specificity in detection of screw loosening was 43.9% and 92.1% for MRI, 64.8% and 96.7% for CT, and 54.2% and 83.5% for standard radiographs, respectively.
Conclusions: Despite improvement of MRI with metal artifact reduction MRI technique, CT remains the modality of choice. Even so, CT fails to detect all loosened pedicle screws.
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http://dx.doi.org/10.1016/j.spinee.2018.06.345 | DOI Listing |
Clin Spine Surg
December 2024
Department of Orthopaedic Surgery, Keio University School of Medicine, Shinjyuku, Tokyo.
Study Design: Multicenter retrospective cohort study.
Objective: To evaluate the efficacy and safety of using cement-augmented pedicle screw (CAPS) fixation only for the cephalad and caudal vertebral bodies.
Summary Of Background Data: Pedicle screw fixation is less effective in patients with low-quality bone.
J Hand Surg Eur Vol
January 2025
Hand Unit, Cardiff and Vale University Health Board, Cardiff, UK.
The use of metalwork, such as screws and plates, is common in orthopaedic trauma surgery, with a recent trend towards individually packed metalwork owing to concerns about sterilization efficacy and traceability. Despite this, there is no clinical evidence proving clinical risk from repeat sterilization of metalworks used in orthopaedic trauma of either increased infection rates or loosening or implant failure. On the contrary, the use of individually packed metalworks presents several practical challenges, including higher costs, increased risks of contamination, longer operative times and a larger carbon footprint.
View Article and Find Full Text PDFJ Dent
January 2025
Senior Research and Teaching Assistant, Clinic of Reconstructive Dentistry, Center for Dental Medicine, University of Zurich, Plattenstrasse 11, 8032 Zurich, Switzerland. Electronic address:
Objectives: A new abutment-free implant connection allows for direct screwing of FDPs on implants to avoid complications caused by cement rests or screw loosening, which may affect to screw torque and load distribution. The objective of this study was to test the initial (Fi) and final failure (Ff) loads and torque changes of abutment-free monolithic zirconia CAD-CAM fixed dental prostheses (FDPs) compared to titanium FDPs on different abutment designs.
Methods: Three-unit screw-retained FDPs (n=50) on two implants (n=100) were divided into groups (n=10) based on the implant-abutment connection and material of the supra-structure: (1) abutment-free monolithic CAD-CAM zirconia FDP (Abut-free-Zr), (2) abutment-free veneered titanium FDPs (Abut-free-Ti), (3) monolithic zirconia FDPs with titanium base abutments (Zr-Ti-Base), (4) monolithic zirconia FDPs on multi-unit abutments (Zr-MU), (5) veneered titanium FDP on multi-unit abutments (Ti-MU).
Acta Orthop
January 2025
Department of Orthopaedics, Leiden University Medical Center, Leiden, The Netherlands.
Background And Purpose: This study updates 2 parallel systematic reviews and meta-analyses from 2012, which established the 1-year radiostereometric (RSA) migration thresholds for tibial components of total knee replacements (TKR) based on the risk of late revision for aseptic loosening from survival studies. The primary aim of this study was to determine the (mis)categorization rate of the 2012 thresholds using the updated review as a validation dataset. Secondary aims were evaluation of 6-month migration, mean continuous (1- to 2-year) migration, and fixation-specific thresholds for tibial component migration.
View Article and Find Full Text PDFLife (Basel)
November 2024
Pediatric Orthopedics and Traumatology, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy.
Background: Fibrous dysplasia (FD) is a rare condition in which normal spongy and cortical bone is replaced by non-neoplastic fibrous tissue, leading to weakened bone matrix and increased risk of pathological fractures and deformities. Treating these deformities poses a significant challenge for surgeons. While various cases of surgical stabilization and limb lengthening using intramedullary nails have been reported, there is limited evidence on the use of Motorized Intramedullary Limb-Lengthening Nails (MILLNs) in FD patients.
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