Custom made knee replacements now available for patients with severe deformities of the knee

Ian McDermottMr Ian McDermott, Consultant Knee Surgeon and Managing Partner of LSO, has recently performed the UK’s first ever Conformis iTotal-PS knee replacement, at The London Bridge Hospital.

Conformis make what many agree is the world’s best knee replacement prosthesis, with the custom-made iTotal knee. This is a prosthesis that is designed and manufactured specifically for each patient’s particular knee with 3D printing with sub-millimetre precision, based on 3D CT scans of the patient’s own joint. This means that the knee prosthesis fits the patient’s knee perfectly, and hence less of the patient’s bone has to be removed and placement of the prosthesis is far more accurate. This leads to better patient outcomes, and studies have shown that with the iTotal prosthesis the kinematics of the knee post-op are significantly improved compared to a standard off-the-shelf prosthesis, and patient satisfaction rates are significantly better, with a greater percentage of patients stating that their knee replacement actually feels like their own normal knee.

Up until now, the Conformis iTotal prosthesis was only available as a posterior cruciate retaining (CR) version. The iTotal CR knee is fine for most cases of knee OA. However, in cases where there is severe deformity and/or instability, then the surgeon might choose to excise the patient’s PCL (as well as the ACL, which is always removed in all knee replacements anyway), and use a Posteriorly Stabilised (PS) knee design. A PS design does remove slightly more tissue and bone, but the benefit is that it has an additional post on the tibial polyethylene insert in the middle of the prosthesis that gives greater stability to the implant, and the PS design allows better outcomes in more severely damaged and more challenging joints.


Conformis have now designed a PS version of their iTotal knee, to add to the portfolio of designs available (the iTotal, the iUni and the iDuo), and this has just been released in the UK.

On Tuesday 10th May, Mr McDermott implanted the UK’s first ever iTotal-PS knee, into the knee of a 71-year-old lady with severe osteoarthritis who had a severe fixed valgus deformity.

MB pre-op Alignment

Pre-operatively, the patient’s valgus measured approximately 17 degrees, and she had severe pain and restricted mobility. The patient had heard about the benefits of custom-made knees and was keen to have a Conformis knee. Mr McDermot had a full and detailed discussion with the patient about the technical difficulties of her specific knee and about the various potential options for this, and the patient opted for the new Conformis iTotal-PS design.

The surgery went extremely well, and Mr McDermott’s comments were that the iTotal-PS prosthesis actually converted the surgery from what would otherwise have been quite a technically challenging operation into a straight-forward relatively easy procedure, and the prosthesis fitted perfectly with excellent correction of deformity and with very good stability.


MB post-op AlignmentPost-operatively, within just days of the surgery, the patient was delighted with her knee, and she has already remarked on how straight the leg now looks and how stable her new knee feels, and on the fact that this actually feels like her own knee already!

The iTotal PS knee has now extended the range of suitable indications as to which patients might be appropriate for a custom-made knee prosthesis, and represents yet another positive step forward in the evolution of knee replacement surgery, and LSO is proud to be at the forefront of 1st class top-of-the-range knee surgery in the UK.

For more information about the Conformis knees and the iTotal PS prosthesis, please just get in touch.



10 July 2016


Custom-made Knee replacement