gms | German Medical Science

Objectives: Malunion of the distal radius can lead to considerable disability due to osteoarthritis and limited range of motion. In such cases, corrective distal radius osteotomy is indicated. The 3-dimensional (3D) planning for osteotomy and drilling guides followed by standard implant fixation or followed by Individual patient solutions (IPS) fixation are the surgical strategies currently in use. Recent reports have yielded unsatisfactory results by standard implants due to misalignment. In these patients, the use of a standard implant may lead to suboptimal distal radius segment position after fixation. New developments in the field of 3D printing have enabled surgeons to use 3D-printed templates for correction osteotomy. Our hypothesis is that the IPS provides more accurate positioning of the distal radius (radial inclination, volar/dorsal tilt, radial height, ulnar variance) compared to the use of conventional, pre-contoured plates.

Method: Prospective study of all consecutive patients treated by IPS based corrective osteotomy of the distal radius since 2019 are assessed for eligibility. The primary endpoint is to measure exact postoperative position of the distal radius portion after IPS based corrective osteotomy compared to the standard implant based osteotomy (radial inclination, volar/dorsal tilt, radial height, ulnar variance) and the residual error shown as the degree to which the positions of the distal segments differ (anatomical coordinate system with rotational x,y, and z axis; Fig. 1). The standard implant based osteotomy is performed on a 3D printed model of the same fracture. The secondary endpoints are the subjective and functional outcome.

Results: The first results with the patient-specific implants are promising. The average deviation of the IPS and the standard plate shows a value of 1,6° and 7,7° (X axis), 2,9° and 5° (Y axis) and 2,4° and 4,3° (Z axis) respectively. The deviation of the radial inclination angle was 2,2° and 1° for the volar tilt for the IPS and 4,5° and 5,9° for the standard plate respectively.

Conclusion: These implants allow the surgeon greater precision in the placement of the implant as well as a bet-ter implementation of the surgical procedure. We would like to operate on more cases in the future to prove that more precise planning including more precise placement of the implants also leads to better clinical results compared to conventional planning on standard implants.