Computer-Assisted Techniques in Corrective Distal Radius Osteotomy Procedures.

Malunion of the distal radius is a common complication following a distal radius fracture. The surgical treatment of a symptomatic distal radius malunion is a corrective osteotomy (CO) procedure aimed at the restoration of the anatomical alignment of the distal radius articular surface in the wrist joint. Traditional two-dimensional imaging techniques in the management of malunion have demonstrated to be limited in pre-, intra-, and postoperative imaging and visualization of the bone architecture. Over the past decades, with the advent of three-dimensional (3-D) imaging techniques, innovations have emerged in the field of preoperative planning, navigation, and 3-D printing. The aim of this paper is to review the existing literature and inform clinicians and biomedical engineers approaching the field about advantages, disadvantages, and future perspectives of existing computer-assisted technology for CO. Collected studies agree on showing the efficacy of the computed-tomography-based 3-D virtual planning. Currently, patient-specific 3-D printed guides and implants are the most promising technology to transfer the preoperative plan to the patient. However, further biomechanical studies, larger clinical trials, and a major exposure of clinicians to 3-D planning are needed to augment the feasibility of using these technologies in standard practice.

Positioning accuracy of a patient-tailored rimmed wedge implant for corrective osteotomy of the distal radius.

Conventional corrective osteotomy surgery is based on 2-D imaging for planning and evaluation of bone positioning. In this feasibility study we propose and evaluate the use of 3-D preoperative planning and design of a custom rimmed wedge to be inserted into the osteotomy gap. The shape of the wedge provides 3-D bone positioning as planned, while the rims keep the bone segments in place. The method is evaluated experimentally using 3-D printed radii specimens of five different malunion patients, as well as in a human cadaver specimen. Positioning was accurate and reproducible showing residual displacements along the x-, y- and z-axes of (mean ± SD): (-0.19 ± 0.75, 0.38 ± 1.09, and 0.47 ± 0.48) mm and residual rotations about these axes of (mean ± SD): (-1.22 ± 1.66, -0.40 ± 0.93, and -0.33 ± 1.50)° for artificial bone specimens. The cadaver experiment showed similar displacements along the x-, y- and z-axes (-0.17, 1.11, and -0.35) mm and residual rotations about these axes (-2.93, -1.53, and 2.31)°. Positioning by inserting a rimmed wedge in corrective osteotomy surgery is accurate with residual errors comparable to bilateral differences. The method seems promising for future utilization in corrective osteotomy surgery and may ultimately render the procedure minimally invasive.