A 60 year old lady was suffering from shoulder pain and limited range of motion. Analysis of the medical images indicated a devastating shoulder arthrosis with severe medialization and erosion of the glenoid. Due to a complete loss of the glenoid vault, implantation of a classic pegged baseplate for reverse total shoulder was not an option. In addition, interposition of a massive bone graft would have little chance for ingrowth and survival, hence little chance to offer sufficient stability.
At the age of 81, the patient was suffering from a Paprosky type 3B defect and already underwent hip revision surgeries prior to seeking the help of Mr. Dunlop. He is not alone, because data from joint registries show that 27% of the revisions is not an initial one and those re-revisions have a 3 times higher chance of failure compared to initial revisions.
Total hip replacement is widely considered a very successful surgery to relieve pain and restore mobility to patients. Since the shape of every patient's femur is different, the femoral offset, anteversion angle and length can vary widely between patients. Therefore, to achieve good functional results, an accurate restoration of hip biomechanics with appropriate implant and sizing options is essential.
In total hip replacement surgery, short hip stems are presumed to reduce proximal stress shielding compared to traditional, long stems. Belgian researchers virtually implanted a commercially available calcar-guided short stem in a series of bones with deviating proximal geometry and performed finite element analyses. Given the large number of FEA models that had to be created, they used an automated methodology.
Patellofemoral joint complication is among the leading causes for the failure of primary total knee replacement. When the joint wears down and a total knee replacement surgery is recommended, one of the goals of the femoral component is to restore the trochlear groove in such a way that the patella follows its natural pathway during knee movement. Exactech performed a study to understand the native, healthy trochlear groove.
A growing number of patients has undergone both a total hip and a total knee replacement in the same leg. Researchers at the Biomechanics section of the University of Leuven wanted to understand whether the distance between the hip and knee implants — the ‘interprosthetic gap’ — would influence the femoral strength. This required a robust workflow for creating accurate finite element models. Using the Materialise Mimics Innovation Suite allowed the researchers to generate accurate surface and volume meshes based on medical image data.
Solutions: FEA, Magics, Magics 3D Print Suite, Metal 3D Printing
In this case study, we investigate different part-support configurations of a patient-specific CMF implant, and determine which configuration is most suitable for the AM process. We do this by simulating deformations via inherent strain method and comparing the final deformations of the parts after support removal.
A 43 year-old female runner suffered a displaced right femoral neck stress fracture that failed to heal with conservative treatment. She was treated at an outside hospital with percutaneous reduction and internal fixation.
Dr. Mehta is an enthusiastic advocate of digital pre-operative planning and has selected OrthoView software as the solution for his division. Here he explains how his division will benefit from using OrthoView for planning and templating procedures.
This total hip arthroplasty (THA) revision case presented by Mr. Grant Shaw is part of our “Plan to Know” with Orthopaedic Digital Templating Case Study Series, in which orthopaedic surgeons describe cases in which digital pre-operative did or would have enabled better preparation for the OR.
Finding out that you are going to have a baby may be one of the happiest days of your life. Sadly for one family in New York, the joy quickly turned to fear and uncertainty when they found out their baby would be born with a complex form of congenital heart disease.
Standard orthopaedic plating systems don’t always match a patient’s anatomy. Prof. Dr. Stockmans used the Mimics Innovation Suite to optimize the design of a hand plating system for an optimal fit through virtual design iterations.