Paediatric musculoskeletal (MSK) disorders often produce severe limb deformities, that may require surgical correction. This may be challenging, especially in case of multiplanar, multifocal and/or multilevel deformities. The increasing implementation of novel technologies, such as virtual surgical planning (VSP), computer aided surgical simulation (CASS) and 3D-printing is rapidly gaining traction for a range of surgical applications in paediatric orthopaedics, allowing for extreme personalization and accuracy of the correction, by also reducing operative times and complications. However, prompt availability and accessible costs of this technology remain a concern. Here, we report our experience using an in-hospital low-cost desk workstation for VSP and rapid prototyping in the field of paediatric orthopaedic surgery. From April 2018 to September 2022 20 children presenting with congenital or post-traumatic deformities of the limbs requiring corrective osteotomies were included in the study. A conversion procedure was applied to transform the CT scan into a 3D model. The surgery was planned using the 3D generated model. The simulation consisted of a virtual process of correction of the alignment, rotation, lengthening of the bones and choosing the level, shape and direction of the osteotomies. We also simulated and calculated the size and position of hardware and customized massive allografts that were shaped in clean room at the hospital bone bank. Sterilizable 3D models and PSI were printed in high-temperature poly-lactic acid (HTPLA), using a low-cost 3D-printer. Twenty-three operations in twenty patients were performed by using VSP and CASS. The sites of correction were: leg (9 cases) hip (5 cases) elbow/forearm (5 cases) foot (5 cases) The 3D printed sterilizable models were used in 21 cases while HTPLA-PSI were used in five cases. customized massive bone allografts were implanted in 4 cases. No complications related to the use of 3D printed models or cutting guides within the surgical field were observed. Post-operative good or excellent radiographic correction was achieved in 21 cases. In conclusion, the application of VSP, CASS and 3D-printing technology can improve the surgical correction of complex limb deformities in children, helping the surgeon to identify the correct landmarks for the osteotomy, to achieve the desired degree of correction, accurately modelling and positioning hardware and bone grafts when required. The implementation of in-hospital low-cost desk workstations for VSP, CASS and 3D-Printing is an effective and cost-advantageous solution for facilitating the use of these technologies in daily clinical and surgical practice

Introduction and Objective. Virtual Surgical Planning (VSP) is becoming an increasingly important means of improving skills acquisition, optimizing clinical outcomes, and promoting patient safety in orthopedics and traumatology. Pediatric Orthopedics (PO) often deals with the surgical treatment of congenital or acquired limbs and spine deformities during infancy. The objective is to restore function, improve aesthetics, and ensure proper residual growth of limbs and spine, using osteotomies, bone grafts, age-specific or custom-made hardware and implants. Materials and Methods. Three-dimensional (3D) digital models were generated from Computed Tomography (CT) scans, using free open-source software, and the surgery was planned and simulated starting from the 3D digital model. 3D printed sterilizable models were fabricated using a low-cost 3D printer, and animations of the operation were generated with the aim to accurately explain the operation to parents. All procedures were successfully planned using our VSP method and the 3D printed models were used during the operation, improving the understanding of the severely abnormal bony anatomy. Results. The surgery was precisely reproduced according to VSP and the deformities were successfully corrected in eight cases (3 genu varum in Blount disease, 2 coxa vara in pseudo achondroplasia, 1 SCFE, 1 missed Monteggia lesion and 1 post-traumatic forearm malunion deformity). In one case, a focal fibrocartilaginous dysplasia, the intraoperative intentional undersizing of the bone osteotomy produced an incomplete correction of a congenital forearm deformity. Conclusions. Our study describes the application of a safe, effective, user-friendly, VSP process in PO surgery. We are convinced that our study will stimulate the widespread adoption of this technological innovation in routine clinical practice for the treatment of rare congenital and post-traumatic limb deformities during childhood

Introduction and Objective. Malunion after trauma can lead to coronal plane malalignment in the lower limb. The mechanical hypothesis suggests that this alters the load distribution in the knee joint and that that this increased load may predispose to compartmental arthritis. This is generally accepted in the orthopaedic community and serves as the basis guiding deformity correction after malunion as well as congenital or insidious onset malalignment. Much of the literature surrounding the contribution of lower limb alignment to arthritis comes from cohort studies of incident osteoarthritis. There has been a causation dilemma perpetuated in a number of studies - suggesting malalignment does not contribute to, but is instead a consequence of, compartmental arthritis. In this investigation the relationship between compartmental (medial or lateral) arthritis and coronal plane malalignment (varus or valgus) in patients with post traumatic unilateral limb deformity was examined. This represents a specific niche cohort of patients in which worsened compartmental knee arthritis after extra-articular injury must rationally be attributed to malalignment. Materials and Methods. The picture archiving system was searched to identify all 1160 long leg x ray films available at a major metropolitan trauma center over a 12-year period. Images were screened for inclusion and exclusion criteria, namely patients >10 years after traumatic long bone fracture without contralateral injury or arthroplasty to give 39 cases. Alignment was measured according to established surgical standards on long leg films by 3 independent reviewers, and arthritis scores Osteoarthritis Research Society International (OARSI) and Kellegren-Lawrence (KL) were recorded independently for each compartment of both knees. Malalignment was defined conservatively as mechanical axis deviation outside of 0–20 mm medial from centre of the knee, to give 27 patients. Comparison of mean compartmental arthritis score was performed for patients with varus and valgus malalignment, using Analysis of Variance and linear regression. Results. In knees with varus malalignment there was a greater mean arthritis score in the medial compartment compared to the contralateral knee, with OARSI scores 5.69 vs 3.86 (0.32, 3.35 95% CI; p<0.05) and KL 2.92 vs 1.92 (0.38, 1.62; p<0.005). There was a similar trend in valgus knees for the lateral compartment OARSI 2.98 vs 1.84 (CI −0.16, 2.42; p=0.1) and KL 1.76 vs 1.31 (CI −0.12, 1.01; p=0.17), but the evidence was not conclusive. OARSI arthritis score was significantly associated with absolute MAD (0.7/10mm MAD, p<0.0005) and Time (0.6/decade, p=0.01) in a linear regression model. Conclusions. Malalignment in the coronal plane is correlated with worsened arthritis scores in the medial compartment for varus deformity and may similarly result in worsened lateral compartment arthritis in valgus knees. These findings support the mechanical hypothesis that arthritis may be related to altered stress distribution at the knee, larger studies may provide further conclusive evidence

The use of retrograde femoral intramedullary nails in children for deformity correction is controversial. It is unknown if the injury to the central part of the growth plate results in premature bony union, leading to limb deformities or discrepancies. The aim of this study was to assess physeal healing and bone growth after insertion of a retrograde femoral nail thorough the centre of the physis in a skeletally immature experimental porcine model. Eleven immature pigs were included in the study. One leg was randomised for operation with a retrograde femoral nail (diameter 10.7 mm), whilst the non-operated contralateral remained as control. All nails were inserted centrally in coronal and sagittal plane under fluoroscopic guidance, and the nails spanned the physis. The nails were removed at 8 weeks. Both femora in all animals underwent MRI at baseline (pre-operatively), 8 weeks (after nail removal) and 16 weeks (before euthanasia). Femoral bone length was measured at 5 sites (anterior, posterior, central, lateral and medial) using 3d T1-weighted MRI. Growth was calculated after 8 weeks (growth with nail) and 16 weeks (growth without nail). Physeal cross-sectional area and percentage violated by the nail was determined on MRI. Operated side was compared to non-operated. Corresponding 95% confidence intervals were calculated. No differences in axial growth were observed between operated and non-operated sides. Mean growth difference was 0,61 mm [−0,78;2,01] whilst the nail was inserted into the bone and 0,72 mm [−1,04;1,65] after nail removal. No signs of angular bone deformities were found when comparing operated side to non-operated side. No premature bony healing at the physis occurred. Histology confirmed fibrous healing. Mean physeal violation was 5.72% [5.51; 5.93] by the femoral nail. The insertion of a retrograde femoral nail through the centre of an open physis might be a safe procedure with no subsequent growth arrest. However, experiments assessing the long term physeal healing and growth are needed

Objectives

To review the systemic impact of smoking on bone healing as evidenced within the orthopaedic literature.