3D Surgical Planning
The technical goals of preoperative planning of the hip joint include restoration of femoral offsets and limb length as well as the restoration of the centre of rotation.
Starting from Computed Tomography (CT) scans, taken with the patient supine within the CT scanner, Three-Dimensional (3D) models of the patient anatomy are created in a virtual 3D environment.
These models are then used to plan the operation, determining implant size, type and positioning in relation to a chosen standard frame of reference; the surgeon acquires valuable information regarding patient anatomy before surgery.
The digital plan can be transferred to patient care by way of 3D printed personalised instruments and surgical guides, so-called Patient-Specific Instruments (PSI). 3D printed, sterilised and used intraoperatively, the physical models aid the surgeon achieving optimal cup and stem sizing and positioning.
The 3D models of the unique bony anatomy may also be aligned with bi-planar radiographs (EOS scans) taken with the patient in more functional positions of standing and seated. This leverages the advantages of both imaging technologies and allows for accurate measurements of pelvic tilt in all three anatomical planes (axial, coronal and sagittal).
Our Publications
Accurate prediction of implant size during preoperative planning in primary and revision hip arthroplasty is an important factor for successful reconstruction, to avoid intra-operative or postoperative complications. In addition, the accuracy of size prediction may facilitate inventory cost savings and reduce the risk of opening (and thus wasting) the packaging of an implant of the wrong size.
3D images of the pelvis may be aligned to the upright EOS scan (as shown above), before measurements of pelvic tilt. The 3D model may also be aligned to the seated EOS scan of the same patient. This provides valuable preoperative information regarding the patient’s pelvic mobility, as the degree of tilt is specific to each individual.
Accuracy of a Three-Dimensional (3D)-Printed Patient-Specific (PS) Femoral Osteotomy Guide: A Computed Tomography (CT) Study
Accuracy of a Three-Dimensional (3D)-Printed Patient-Specific (PS) Femoral Osteotomy Guide: A Computed Tomography (CT) Study
Can 3D surgical planning and patient specific instrumentation reduce hip implant inventory? A prospective study
Can 3D surgical planning and patient specific instrumentation reduce hip implant inventory? A prospective study
Three-dimensional pre-operative planning of primary hip arthroplasty: a systematic literature review
Three-dimensional pre-operative planning of primary hip arthroplasty: a systematic literature review
What Is the Functional Spinopelvic Relationship in Three Dimensions? A CT and EOS Study
What Is the Functional Spinopelvic Relationship in Three Dimensions? A CT and EOS Study
Image Analysis of Implants
There is almost no benefit in performing surgical planning if we do not check whether we have achieved it. Plan and implant design have a direct impact on performance.
Improvements in CT hardware and software have increased scan quality while also reducing the radiation dose.
The advent of specialised software for medical image analysis are forging the use of new strategies to evaluate surgical outcome.
One of the main applications is the evaluation of surgical outcome comparing implant position achieved at surgery with the pre-operatively CT-based planned position.
Recent studies, clinical and experimental, are showing that that with methods using CT data it is now possible to replace RSA for implant monitoring and that this analysis can constitute a valuable tool to aid post-market surveillance.
Our Publications
