3D-Printed Cutting Guides for Lower Limb Deformity Correction

Background:
Patient-specific instruments (PSI) and surgical-guiding templates are gaining popularity as a tool for enhancing surgical accuracy in the correction of oblique bone deformities.

Three-dimensional virtual surgical planning technology has advanced applications in the correction of deformities of long bones and enables the production of 3D stereolithographic models and PSI based upon a patient`s specific deformity. We describe the implementation of this technology in patients who required a corrective osteotomy for a complex three-plane (oblique plane) lower-limb deformity.

Methods:
Radiographs and computerized tomographic (CT) scans (0.5 mm slices) were obtained for each patient. The CT images were imported into post-processing software, and virtual 3D models were created by a segmentation process. Femoral and tibial models and cutting guides with locking points were designed according to the deformity correction plan as designed by the surgeon. The models were used for preoperative planning and as an intraoperative guide. All osteotomies were performed with the PSI secured in the planned position.

Results:
A total of 17 patients (9 males and 8 females, average age 14.7 years [range 8-24]). During surgery, all of the PSI fit to the bone surfaces as planned. The osteotomies matched the preoperative planning simulation and allowed for easy fixation with pre-chosen plates. No intra- or postoperative complications were encountered. Surgery time was shortened (101 minutes) and intraoperative blood loose was less compared to historical cases. Clinical and radiographic follow-up findings showed highly satisfactory alignment of the treated extremities in all 17 patients.

Conclusion:
The use of 3D-printed models and patient-specific cutting guides with locking points increases accuracy, shortens procedure time, reduces intraoperative blood loss, and improves the outcome of osteotomies in young patients with complex oblique bone deformities.