A computer simulation protocol to assess the accuracy of a Radio Stereometric Analysis (RSA) image processor according to the ISO-5725

Radio-Stereometric-Analysis and x-ray fluoroscopy are radiological techniques that require dedicated software to process data. The accurate calibration of these software is therefore critical. The aim of this work is to produce a protocol for evaluating the softwares' accuracy according to the ISO-5725. A series of computer simulations of the radiological setup and images were employed. The noise level of the images was also changed to evaluate the accuracy with different image qualities. The protocol was tested on a custom software developed by the authors. Radiological scene reconstruction accuracy was of (0.092 +- 0.14) mm for tube position, and (0.38 +- 0.31) mm / (2.09 +- 1.39) deg for detectors oriented in a direction other than the source-detector direction. In the source-detector direction the accuracy was of (2.68 +- 3.08) mm for tube position, and of (0.16 +- 0.27) mm / (0.075 +- 1.16) deg for the detectors. These disparate results are widely discussed in the literature. Model positioning and orientation was also highly accurate: (0.22 +- 0.46) mm / (0.26 +- 0.22) deg. Accuracy was not affected by the noise level. The protocol was able to assess the accuracy of the RSA system. It was also useful to detect and fix hidden bugs. It was also useful to detect and resolve hidden bugs in the software, and in optimizing the algorithms

Custom-made implants for massive acetabular bone loss: accuracy with CT assessment

Background: Custom-made implants are a valid option in revision total hip arthroplasty to address massive acetabular bone loss. The aim of this study was to assess the accuracy of custom-made acetabular implants between preoperative planning and postoperative positioning using CT scans. Methods: In a retrospective analysis, three patients who underwent an acetabular custom-made prosthesis were identified. The custom-made designs were planned through 3D CT analysis considering surgical points of attention. The accuracy of intended implants positioning was assessed by comparing pre- and postoperative CT analyzing the center of rotation (CoR), anteversion, inclination, screws, and implant surface in contact with the bone. Results: The three cases presented satisfactory accuracy in positioning. A malpositioning in the third case was observed due to the posterization of the CoR of the implant of more than 10 mm. The other CoR vectors considered in the third patient and all vectors in the other two cases fall within 10 mm. All the cases were positioned with a difference of less than 10° of anteversion and inclination with respect to the planning. Conclusions: The current case series revealed promising accuracy in the positioning of custom-made acetabular prosthesis comparing the planned implant in preoperative CT with postoperative CT

Total knee arthroplasty in valgus knee deformity: is it still a challenge in 2021?

Total knee arthroplasty in valgus knee deformities continues to be a challenge for a surgeon. Approximately 10% of patients who undergo total knee arthroplasty have a valgus deformity. While performing total knee arthroplasty in a severe valgus knee, one should aware with the technical aspects of surgical exposure, bone cuts of the distal femur and proximal tibia, medial and lateral ligament balancing, flexion and extension gap balancing, creating an appropriate tibiofemoral joint line, balancing the patellofemoral joint, preserving peroneal nerve function, and selection of the implant regarding constraint. Restoration of neutral mechanical axis and correct ligament balance are important factors for stability and longevity of the prosthesis and for good functional outcome. Thus, our review aims to provide step by step comprehensive knowledge about different surgical techniques for the correction of severe valgus deformity in total knee arthroplasty

Weight bearing versus conventional CT for the measurement of patellar alignment and stability in patients after surgical treatment for patellar recurrent dislocation

Purpose: To compare weight-bearing cone-beam computer tomography (CBCT) and conventional computer tomography (CT)-based measurements of patellofemoral alignment and stability in patients surgically treated for recurrent patellar dislocation. These scans implied respectively single-leg up-right posture, the knee flexed, and lower limb muscles activation, versus supine position with the knee extended. Methods: A total of 17 patients (11 males/6 females) after surgical reconstruction with fascia lata allograft for recurrent patellofemoral dislocation were analyzed at 60-month follow-up. Tilt and congruence angles and tibial tuberosity–trochlear groove (TT-TG) offset were measured on images obtained from CBCT and conventional CT scans by three independent and expert radiologists. Paired t tests were performed to compare measurements obtained from the two scans. Inter-rater reliability was assessed using a two-way mixed-effects model intra-class correlation coefficient (ICC). Results: Only TT-TG offset was found significantly smaller (p < 0.001) in CBCT (mean 9.9 ± 5.3 mm) than in conventional CT (mean 15.9 ± 4.9 mm) scans. ICC for tilt and congruence angles and for TT-TG offset ranged between 0.80–0.94 with measurements in CBCT scans, between 0.52 and0.78 in conventional CT. Conclusion: In patients surgically treated for recurrent patellar dislocation, TT-TG offset was found overestimated with conventional CT. All measurements of patellofemoral stability and alignment were found more consistent when obtained with weight-bearing CBCT compared to conventional CT

Pathophysiology of Lateral Patellar Dislocation

Despite numerous studies, a lack of consensus still exists over many aspects of patellofemoral pain, instability, and arthritis. This book adopts an evidence-based approach to assess each of these topics in depth. The book reviews general features of clinical examination and global evaluation techniques including the use of different imaging methods, e.g. x-rays, CT, MRI, stress x-rays, and bone scan. Various conservative and surgical treatment approaches for each of the three presentations \u2013 pain, instability, and arthritis \u2013 are then explained and assessed. Postoperative management and options in the event of failed surgery are also evaluated. Throughout, careful attention is paid to the literature in an attempt to establish the level of evidence for the efficacy of each imaging and treatment method. It is hoped that this book will serve as an informative guide for the practitioner when confronted with disorders of the patellofemoral joint

le suture menscali

Indice PARTE GENERALE PARTE SPECIALE - Ginocchio - Lesioni del legamento crociato anteriore - Menisco - Legamento crociato posteriore e plastiche esterne - Cartilagine - Osteotomia tibiale correttiva in associazione a ricostruzione del legamento crociato anteriore MEMBRANA SINOVIALE LA SPALLA - Instabilit\ue0 della spalla: inquadramento e tecnica chirurgica - Lesioni della cuffia dei rotatori - Miscellanea GOMITO CAVIGLIA E PIEDE POLSO ANC

High tibial osteotomy: the italian experience

Osteotomy is one of the more ancient orthopaedic procedures still used today. Today, new knowledge and technology about bone healing and better fixations to accelerate postoperative management have allowed high tibial osteotomy to become a useful procedure for active patients younger than 60 years of age with symptomatic unicompartmental disease and osseous deformity of the knee. An important advantage of this procedure is the possibility of combining with it the articular cartilage procedure (osteochondral grafts, autologous chondrocyte implantation), meniscus transplantation, or ligament reconstruction. The 2 main techniques to produce valgus realignment of the knee are lateral closing wedge osteotomy and medial opening wedge osteotomy. We also can perform elevation osteotomy in posttraumatic cases and procurvation osteotomy to correct genu recurvatum. Most complications resulting from osteotomy can be avoided by careful patient selection and accurate preoperative planning. Therefore, the role of high tibial osteotomy is not only curative as in treating cartilage damage and posttraumatic axial deviation in patients older than 50 years but also preventive in degenerative joint diseases of young patients with congenital or posttraumatic axial deviation or anatomical deformation of the knee join