RESUMO
BACKGROUND: The paediatric patient population has considerable variation in anatomy. The use of Computed Tomography (CT)-based digital models to design three-dimensionally printed patient specific instrumentation (PSI) has recently been applied for correction of deformity in orthopedic surgery. This review sought to determine the existing application of this technology currently in use within paediatric orthopaedics, and assess the potential benefits that this may provide to patients and surgeons. METHODS: A review was performed of MEDLINE, EMBASE, and CENTRAL for published literature, as well as Web of Science and clinicaltrials.gov for grey literature. The search strategy revolved around the research question: "What is the clinical impact of using 3D printed PSI for proximal femoral or pelvic osteotomy in paediatric orthopaedics?" Two reviewers, using predetermined inclusion criteria, independently performed title and abstract review in order to select articles for full text review. Data extracted included effect on operating time and intraoperative image use, as well as osteotomy and screw positioning accuracy. Data were combined in a narrative synthesis; meta-analysis was not performed given the diversity of study designs and interventions. RESULTS: In total, ten studies were included: six case control studies, three case series and a case report. Five studies directly compared operating time using PSI to conventional techniques, with two showing a significant decrease in the number of intraoperative images and operative time. Eight studies reported improved accuracy in executing the surgical plan compared to conventional methods. CONCLUSION: Compared to conventional methods of performing femoral or pelvic osteotomy, use of PSI has led to improved accuracy and precision, decreased procedure times, and decreased intra-operative imaging requirements. Additionally, the technology has become more cost effective and accessible since its initial inception and use.
RESUMO
PURPOSE: An optoelectronic surgical navigation system was used to detect small but measurable translational motion of human hip cadavers in high-range passive motions. Kinematic data were also examined to demonstrate the role of soft tissues in constraining hip translation. METHODS: Twelve cadaver hips were scanned using CT, instrumented for navigation, and passively taken through motion assessment. Center of the femoral head was tracked in the acetabular coordinates. Maximum non-impinging translation of the femoral head for each specimen hip was reported. This was repeated for 5 tissue states: whole, exposed to the capsule, partially or fully incised capsule, resection of the ligamentum teres and labrectomy. Femoral motions were compared to the reported value for ideal ball and socket model. RESULTS: Whole and exposed hips underwent maximal translations of [Formula: see text] and [Formula: see text] mm, respectively. These translational motions were statistically significantly different from reported value for a purely spherical joint, [Formula: see text]. Further tissue removal almost always significantly increased maximum non-impingement translational motion with [Formula: see text]. CONCLUSION: We found subtle but definite translations in every cadaver hip. There was no consistent pattern of translation. It is possible to use the surgical navigation systems for the assessment of human hip kinematics intra-operatively and improve the treatment of total hip arthroplasty patients by the knowledge of the fact that their hips translate. Better procedure selection and implantation optimization may arise from improved understanding of the motion of this critically important human joint.