Precision in hip replacement positioning directly translates to longevity, stability, and patient satisfaction. Modern pre-operative planning has evolved from basic 2D templating to sophisticated 3D virtual surgery. Combined with custom jigs and intra-operative imaging, I can now position hip implants with accuracy within 1 millimetre — an unprecedented level of precision that optimises outcomes for every patient.
How Pre-Operative Planning Has Advanced
Early hip replacement planning relied on 2D X-ray templating. While functional, this method had inherent limitations. The exact magnification of X-rays could vary, and bone rotation was difficult to account for. Surgeons often discovered during surgery that the pre-operative plan didn't match the patient's actual anatomy.
3D planning changed everything. Using CT or advanced imaging, I can now perform virtual hip replacement surgery weeks before you arrive at the hospital. I know the exact size, shape, position, and orientation of your individual hip anatomy. I can position the implant components in three dimensions and see how they interact before making a single cut.
"3D planning allows me to perform your surgery virtually before ever entering the operating theatre. Precision at this level was impossible just a decade ago."
— Dr Chien-Wen LiewWhat Happens During Pre-Operative Imaging
The 3D imaging process is remarkably simple and fast. You lie in the scanner for approximately 30 seconds while a special 3D scan is acquired. This is not an MRI requiring lengthy scanning times — it is a quick, high-resolution 3D image of your hip anatomy. The radiation exposure is minimal and comparable to a few standard X-rays.
Once the scan is complete, I perform comprehensive pre-operative planning. Using specialised software, I plan the exact size, shape, and position of each implant component specific to your anatomy. This virtual surgery is performed in three dimensions, allowing precise positioning that accounts for the patient's individual bone geometry, alignment, and hip anatomy.
Watch Dr Chien-Wen Liew discuss this topic.
Manufacturing Precision Tools for Your Hip
After virtual planning is complete, a custom jig — a precision surgical guide — is manufactured specifically for your anatomy. This jig is a perfect fit with your individual bone surfaces and femoral canal. It enables surgeons to prepare your hip bones with unprecedented accuracy, ensuring that the implant components are positioned exactly as planned.
Every patient gets a unique jig. This patient-specific technology is expensive and time-consuming to produce, but the accuracy it provides is invaluable. No two hips are identical, and no two jigs are identical. Each is custom-made to optimise accuracy for that specific patient's anatomy.
Real-Time Imaging During Surgery
Even with 3D planning and custom jigs, I verify implant positioning during surgery using intra-operative X-ray imaging. Our surgical table allows real-time X-ray scanning without repositioning the patient. This allows me to confirm that the implants are positioned exactly as planned before final fixation.
This intra-operative check is invaluable. If positioning is not optimal, I can adjust before the implants are permanently secured. This additional layer of quality control ensures that the final implant positioning meets my exacting standards for precision and alignment.
Why Every Patient Deserves This Approach
You might ask: why plan 3D for every patient? Don't some hips have "normal" anatomy that doesn't require special planning? The answer is that we cannot predict which hips will have anatomical variations. Approximately 40% of patients have some kind of anatomical abnormality or variant that requires additional pre-operative planning to ensure optimal positioning.
Because I cannot predict which patients will have these variations, I perform 3D planning and patient-specific technology for every hip replacement. This universal approach ensures that every patient receives the same exacting level of precision, regardless of whether their anatomy is straightforward or complex.
Download Planning Technology Guide
A detailed explanation of 3D planning, patient-specific jigs, and precision imaging in hip replacement.