Surgical Treatment of Long-Bone Deformities: 3D Preoperative Planning and Patient-Specific Instrumentation

Abstract

Congenital or posttraumatic bone deformity may lead to reduced range of motion, joint instability, pain, and osteoarthritis. The conventional joint-preserving therapy for such deformities is corrective osteotomy-the anatomical reduction or realignment of bones with fixation. In this procedure, the bone is cut and its fragments are correctly realigned and stabilized with an implant to secure their position during bone healing. Corrective osteotomy is an elective procedure scheduled in advance, providing sufficient time for careful diagnosis and operation planning. Accordingly, computer-based methods have become very popular for its preoperative planning. These methods can improve precision not only by enabling the surgeon to quantify deformities and to simulate the intervention preoperatively in three dimensions, but also by generating a surgical plan of the required correction. However, generation of complex surgical plans is still a major challenge, requiring sophisticated techniques and profound clinical expertise. In addition to preoperative planning, computer-based approaches can also be used to support surgeons during the course of interventions. In particular, since recent advances in additive manufacturing technology have enabled cost-effective production of patient-and intervention-specific osteotomy instruments, customized interventions can thus be planned for and performed using such instruments. In this chapter, state of the art and future perspectives of computer-assisted deformity-correction surgery of the upper and lower extremities are presented. We elaborate on the benefits and pitfalls of different approaches based on our own experience in treating over 150 patients with three-dimensional preoperative planning and patient-specific instrumentation.

Conventional Versus Computer-Assisted Corrective Osteotomy of the Forearm: a Retrospective Analysis of 56 Consecutive Cases

“…Detailed descriptions of the applied planning and guide design techniques can be found in previously published studies. 15 The patient-specific guides were manufactured based on the preoperative simulation by selective laser-sintering using biocompatible polyamide PA 2200 (Medacta SA, Castel San Pietro, Switzerland).…”

Digitalization of the IOM: A comprehensive cadaveric study for obtaining three-dimensional models and morphological properties of the forearm’s interosseous membrane

“…Also, the changes in CSA during loading should be analysed in a similar fashion as performed by Scholze, et al 69 . Furthermore, in order to standardise the relative position between the radius and ulna among the different measurements, we suggest the use of specimenspecific custom-made guides, similar to the currently used 3D-printed guides for intraoperative navigation 2,[70][71][72] . Regarding the anatomical discrepancies with respect to the size of the ligaments' fibres, we would advise performing a standardization of the samples in terms of relative percentage according to the bone size 30 .…”

“…The use of clinical static images for the preoperative planning of surgical procedures is the state of the art [1][2][3] . Previous studies have emphasised the need for dynamic models for the preoperative planning [3][4][5] , in order to study the influence of the surrounding muscles, tendons and ligament on the surgical outcome.…”

The impact of mal-angulated femoral rotational osteotomies on mechanical leg axis: a computer simulation model

“…The bone models were imported into the in-house developed surgical planning software CASPA (Balgrist CARD AG, Zurich, Switzerland). Measuring the antero-posterior (AP)-projected 3D mechanical leg axis, using a measurement method similar to the one described by Fürnstahl et al [19], showed 2.4°valgus for Model 1 and 5.1°valgus for Model 2. A line segment connecting the center of the femoral head and the center of the intercondylar notch represented the femoral mechanical axis.…”