Strategies for surgical reconstruction of complex elbow deformities based on patient-specific instruments - a case series and narrative review.

Objectives: The application of 3D-based methods for deformity correction of the upper extremity, including patient-specific instruments (PSIs), is attracting increasing attention in clinical practice and requires the collaboration of orthopaedic surgeons and medical engineers. Methods: The management of various elbow deformities using 3D-based surgical methods, including PSIs, is presented. A narrative literature review with a defined search strategy using PubMed as a database was conducted to identify further applications around the elbow that have been published to date. Results: This case series presents with one case each the correction of the following deformities: cubitus varus, dorsal radial head subluxation, translational deformity of the distal humerus, cubitus valgus (CVL) and radial head dislocation in hereditary multiple exostoses (HME). The Supplementary literature with 28 studies presents further deformities that were corrected on a 3D basis: intra-articular fracture of the capitulum radii, extension deformity of the distal humerus and malunited radial neck fractures. These 3D-based procedures have been used most frequently to correct cubitus varus and are superior to conventional methods in terms of accuracy in comparative studies. Conclusions: The application of 3D-based planning methods, including PSIs use, offers excellent opportunities and accuracy for corrective osteotomies around the elbow. In addition to the correction of cubitus varus, extension to the correction of chronic dislocation of the radial head after Monteggia fracture and HME appears promising. The future implementation of 3D-based planning based on magnetic resonance imaging (MRI) would be highly desirable.