RESUMEN
Surgical procedures to correct hip dysplasia associated with subluxation or dislocation of the femoral head are complex. The 3D geometric abnormalities of the acetabulum and proximal femur vary across patients. We, therefore, suggest a patient-specific surgical treatment involving computer-assisted 3D planning of the peri-acetabular osteotomies, taking into account the femoral head position; 3D printing of patient-specific guides for the cuts, repositioning, and fixation; and intra-operative application of the simulated displacements with their fixation. LEVEL OF EVIDENCE: IV.
Asunto(s)
Acetábulo , Imagenología Tridimensional , Osteotomía , Impresión Tridimensional , Cirugía Asistida por Computador , Humanos , Osteotomía/métodos , Acetábulo/cirugía , Acetábulo/diagnóstico por imagen , Niño , Adolescente , Cirugía Asistida por Computador/métodos , Masculino , Femenino , Cuidados Preoperatorios/métodos , Luxación de la Cadera/cirugía , Luxación de la Cadera/diagnóstico por imagen , Luxación Congénita de la Cadera/cirugía , Luxación Congénita de la Cadera/diagnóstico por imagen , Tomografía Computarizada por Rayos XRESUMEN
PURPOSE: To compare the accuracy of evaluating deformity in distal radius malunions using plain radiographic measurements compared with a 3-dimensional method involving 3-dimensional computer bone models. METHODS: Consecutive patients who had an extra-articular distal radius malunion were included. Standard radiographs and computed tomography scans of both wrists were performed. Palmar tilt, radial tilt, and ulnar variance were measured on radiographs. The computed tomography scan data were sent to a workstation and 3-dimensional bone surface models of the radius were created. The 3-dimensional palmar tilt, 3-dimensional radial tilt, 3-dimensional ulnar variance, and axial rotational deformity were calculated. RESULTS: Thirteen patients, mean age 40 years (range, 22-57 years) were included. The 3 3-dimensional values were positively correlated with their corresponding radiographic values. Nevertheless, the 3-dimesional palmar tilt and 3-dimensional radial tilt values were slightly smaller than the radiographic palmar tilt and radial tilt. The quantitative difference between the 3-dimensional method and plain radiographs was on average 2° for the dorsal deformity group and 3° for the palmar deformity group. The 3-dimensional ulnar variance was significantly higher than the radiographic ulnar variance by an average of +1.3 mm for malunions with dorsal tilt and +0.6 mm for malunions with palmar tilt. The 3-dimensional method allowed us to measure the extent of the axial rotational deformity, which was 9° on average (range, 2° to 21°). CONCLUSIONS: Despite small differences, measurements made on both plain radiographs and 3-dimensional computer bone models are accurate for evaluating the deformity in extra-articular distal radius malunions. Our 3-dimensional method seems to provide a more accurate measurement of ulnar variance, particularly for dorsally angulated cases, and is helpful for measuring rotational malalignment. CLINICAL RELEVANCE: In this study, we found that either a 3-dimensional computer bone model or plain radiographs can be used as a benchmark to evaluate the deformity of extra-articular distal radius malunion. The 3-dimensional method can also be used to define axial rotational deformity.
Asunto(s)
Huesos del Carpo , Fracturas Mal Unidas , Fracturas del Radio , Adulto , Fracturas Mal Unidas/diagnóstico por imagen , Humanos , Radio (Anatomía) , Fracturas del Radio/diagnóstico por imagen , Articulación de la Muñeca/diagnóstico por imagenRESUMEN
BACKGROUND: The aim of this in vitro study was to assess the accuracy of three-dimensional patient-specific cutting guides for open wedge high tibial osteotomy (OWHTO) to provide the planned correction in both frontal and sagittal planes. METHODS: Ten cadaveric tibias underwent OWHTO performed using a patient-specific cutting guide based on 3D preoperative planning. An initial CT scan of the tibias was performed, and after segmentation, 3D geometrical models of the pre-OWHTO tibias were obtained. Reference planes were defined, and OWHTO virtually planned to then design patient-specific cutting guides. OWHTO were performed using the patient-specific cutting guides. The patient-specific cutting guide controls the cut and the correction of the OWHTO in both planes. 3D models of post-OWHTO tibias were created after a postoperative CT scan. Geometrical post-OWHTO 3D models were superimposed on pre-OWHTO 3D models. Mechanical medial proximal tibial angle (mMPTA) in the frontal plane and posterior tibial slope (PTS) in the sagittal plane were compared between planned-OWHTO and post-OWHTO 3D reconstructions relative to the pre-OWHTO reference planes and axis. Pearson's and Lin's correlation tests were performed to assess precision and accuracy of patient-specific cutting guides. RESULTS: The mean difference between post-OWHTO and planned-OWHTO was 0.2° (max 0.5°, SD 0.3°) in the frontal plane and - 0.1° (max 0.8°, SD 0.5°) in the sagittal plane. Statistically significant correlations were found between the planned-OWHTO and post-OWHTO configurations for the mMPTA (p < 0.0001) and PTS (p < 0.0001) measurements, and the bias correction factor was 0.99 in both planes. CONCLUSIONS: 3D patient-specific cutting guides for OWHTO-based 3D virtual planning is a reliable and accurate method of achieving multiplanar correction in both frontal and sagittal planes.