Matching precision of the reverse contralateral radial head in generating of the individualized prosthesis from the surface registration in tuberosity-neck and in tuberosity-diaphysis

Abstract

Purpose: Following the radial head replacement, the surface mismatches between the implants and the morphological characteristics of the original proximal radius decreased contact areas and increased contact forces which is potential for the long-term articulating cartilage wear. Several studies demonstrated that the individualized prosthesis, created from computed tomographic (CT) images of the contralateral side with the reverse engineering technology, may reduce the mismatch. The aim of this study is to demonstrate the matching precision of the reverse contralateral head between the surface registration in tuberosity-neck (TN) area and in tuberosity-diaphysis (TD) area. Materials and Methods: Highresolution CT scan of 11 pairs of the cadaveric arms was performed. Utilizing advanced image processing techniques, three-dimensional (3-D) models of each specimen was generated. The model of the left side was reversed and matched with the model of the right side in the same cadaver by registering in the area of radial neck along with tuberosity (TN) and in the area of radial tuberosity combined with 2 cm of proximal diaphysis (TD). The alteration of the head diameter, dish diameter, articular depth, head thickness, end-plane angle, offset, and head volume were evaluated and analyzed by paired t-test. Results: No statistically significant difference was found in all parameters from both TN and TD registrations (p < 0.05). Conclusion: The surface registration in either TN or TD area can generate the statistically symmetrical 3-D model with the original head. The registration in these areas may possibly be used in creating the individualized radial head prosthesis.

Fracture Pattern Influences Radial Head Replacement Size Determination Among Experienced Elbow Surgeons

“…This study revealed also that the estimation of the Rh implant height on lateral radiographs is poorly reproducible among surgeons (ICC: 0.443) [36]. CT scans, when available, can provide additional information on Rh anatomy and guide the surgeon towards the appropriate size planning [13,[36][37][38].…”

The patient-specific implant created with 3D printing technology in treatment of a severe open distal humerus fracture with complete loss of the lateral column

“…Based on the symmetry of the human skeleton, we can reverse the 3D images of the normal bone to the contralateral side to create the anatomic prosthesis for the missing part. 12 Using this technique, the tailor-made prostheses for several bones and joints have been previously reported. 13,14 The recent biomechanic study in the cadaveric arms demonstrated that the reverse-engineered distal humeral hemiarthroplasty prostheses did not reproduce the same contact pattern as the native joints, possibly because the prostheses were designed based on distal humeral osseous anatomy from the CT images which is lacked inclusion of the cartilage thickness.…”

Radial head replacement with the 3D-printed patient-specific titanium prosthesis: Preliminary results of a multi-centric prospective study

“…8,9 Based on the symmetry of the human skeleton, the 3D images of normal radial head can be reversed to manufacture the prosthesis of contralateral side which has the accurate shape and dimension for the missing part. 10 In addition, 3D preoperative planning can be used to generate the intraoperative guide in order to implant the prosthesis in the correct position. 8 A previous morphological analysis demonstrated that, in the setting of ideal prosthetic placement, the patient-specific implants generated from the contralateral intact radial head had less surface mismatch than the commercially available designs.…”