A meeting in Lyon
A meeting with Ms Delphine Henry, Director of R&D for Blueprint and PSI (Patient Specific Instrumentation) at Tornier, Wright Medical, to discuss the future development of the Blueprint planning software for shoulder arthroplasty.
What planning software and patient specific instrumentation do
Planning software for shoulder arthroplasty takes a CT scan of the patient's own shoulder and builds a three-dimensional model of it. The surgeon can then try implant sizes and positions on that model before the operation, rather than judging them from plain X-rays and from what can be seen through the wound on the day. Where the socket has worn unevenly, which is common in arthritis, the model shows how much bone is left and in which direction it has been lost.
Patient specific instrumentation follows from that. Once a position has been planned, a guide can be manufactured to fit that individual patient's bone in only one orientation, so the plan is carried into theatre physically rather than from memory. Shoulder arthroplasty itself means replacing the worn surfaces of the shoulder joint with implants, and how accurately the socket component is placed is one of the factors that affects how a replacement behaves over time. Individual results vary.
Extending planning software to instability
A more interesting part of the discussion concerned using the software outside joint replacement, to assess patients with shoulder instability who have had previous dislocations.
The potential value is in selection. Deciding between a soft tissue repair and a bone block procedure such as the Latarjet turns largely on how much bone has been lost from the front of the socket and on the shape of what remains, which is exactly what three-dimensional planning software is built to measure. Being able to quantify that reliably would make the decision less a matter of judgement from two-dimensional images. It is a concept worth developing.
The reason it matters to patients is that the two operations differ in scale. A soft tissue repair reattaches the torn labrum and capsule to the rim of the socket through keyhole portals. A bone block procedure moves bone onto the front of the socket to deepen it, which is a larger undertaking with its own risks. Individual results vary.
Related information
- Our shoulder instability page
- Our Latarjet with labral repair page
- Our post on Blueprint planning software
- Our post on Latarjet stabilisation