A 64-year-old patient suffered from severe complications related to total shoulder arthroplasty performed several years ago. His diagnosis claimed a defect with abnormal ossification surrounding the glenoid. Due to the complexity and unusual size of this particular defect, implementing a patient-specific 3D-Printed Glenius implant seemed to offer the best solution. Prof. Dr. Stefaan Nijs (Belgium) proceeded with a two-stage revision procedure based on detailed 3D preoperative planning.
The patient, an 86 year-old woman who was the primary caregiver for her husband, had previously been an active person in the local community. She was experiencing increasing right knee pain and deformity and was unable to walk without the use of a cane. A physical examination revealed antero-posterior and medial instability with 10-degree hyperextension to 90-degree flexion
OrthoView is able to present the full range of options and compatibilities available with complex modular prostheses on-screen so that the surgeon does not need to memorize them. The surgeon is also able to identify that the correct amount of offset is achievable with the chosen prosthesis.
The patient has a history of hypophosphatemic rickets. The associated bone abnormalities and leg malalignment had been addressed by bilateral closing wedge tibial osteotomies when the patient was approximately 40 years of age. The patient was now experiencing pain in both knees and was having difficulty walking.
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.