9 February 2011 – Study shows 3D planning and patient-specific guides aid in the precise planning and execution of osteotomies around the knee
conducted by Dr. J. Victor, AZ St Lucas, Brugge,
computer-assisted surgical planning and patient-specific surgical
guides in correcting lower limb malalignment. In this study,
Materialise’s SurgiCase Orthopaedics was used to describe lower limb
malalignment and virtually plan multi-planar correction using CT scans.
It was proven that planned corrections can be obtained and fixed
accurately during surgery with the help of Materialise’s
patient-specific surgical guides.
Despite recent innovations, lower limb malalignment continues to be
corrected using traditional methods and techniques, i.e. relying on 2D
plain X-rays and using rulers and protractors, although this can be
prone to error and in some cases, inaccurate in multi-planar
deformities.Therefore, the aim of this pilot study was to evaluate the
feasibility of virtual pre-operative 3D planning and correct execution
of osteotomies around the knee with the aid of patient-specific
Eight patients presenting with significant malalignment of the lower
limb were included in the study (7 valgus, 1 varus knee). Pre-operative
CT scans of the affected limbs and the normal contra-lateral side were
obtained and sent to Materialise where 3D models of the patients’
anatomy were created. These models made it possible for Dr. Victor to
carefully evaluate the three-planar deformity of each patient and
identify customized surgical corrections.
After creating the virtual surgical plans with Dr Victor, the
Materialise team – in close collaboration with Dr. Victor – continued
designing the patient-specific surgical guides used to perform the
planar osteotomy and achieve the planned wedge opening and hinge axis
orientation. These guides were also used in the drilling of the planned
screw holes and thus, determined the position of the plate relative to
the bone. Post-operative assessments of the corrections were obtained
through AP and Lateral X-rays, and full leg standing X-rays.
The results of the study are promising. All of the patient-specific
guides were successfully used during surgery and accurately guided the
osteotomy plane and screw holes. The guides fit uniquely onto the
patients’ bones and it was possible to perform the osteotomies through
the guides. The predrilled screw holes matched the locking plates and
adequate fixations were obtained. No significant peri-operative
Materialise will be exhibiting at the AAOS 2011 annual meeting in
SOURCE Materialise N.V.