Craniovertebral fusion in an infant using struts of banked adult bone.

PURPOSE: The aim of this paper is to discuss the problems of craniocervical instability and craniocervical fusion in infancy. Despite the relative frequency of carniovertebral joint malformations, actual instability is quite rare in infancy. METHODS: An infant 8 months of age presented with tetraparesis and sleep apnea due to a complex malformation of her craniovertebral joint. An initial attempt at conservative treatment using a rigid neck collar failed, so the patient was surgically managed by the onlay placement of two autologous rib grafts. The rigid collar was maintained for 5 months. RESULTS: Both rib grafts progressively reabsorbed within a few months, while the clinical deficits recurred. Reoperation consisted of occipitocervical interposition of two robust struts of banked cadaveric adult fibula. This time, the skull appeared mature enough to allow immobilization by the halo system. Adequate occipitocervical fusion was eventually achieved, and the patient fully recovered. CONCLUSIONS: To the best of our knowledge, there is no other reported case of an infant undergoing craniovertebral fusion using cadaveric adult bone. When screw placement is not considered advisable to manage small infants, appropriate stability may be obtained using struts of robust cadaveric bone. A meticulous carpentry technique with graft interposition under compression and adequate postoperative immobilization remains mandatory.

Biomechanical analysis of posteromedial tibial plateau fracture fixation in fresh cadaveric bone.

This study aims to compare the mechanical strength of three different posterior-based internal fixation methods for posteromedial tibial plateau fractures. The study utilized 12 tibial plateaus harvested from fresh-frozen cadavers, and the posteromedial fracture fragments were created. The bones were then randomly assigned to one of three fixation methods: two posteroanterior lag screws (LS) size 4.0 mm, posterior buttress plate using a 3.5 mm small dynamic compression plate (DCP), or posterior buttress plate using a 3.5 mm T-shaped plate (TP). Biomechanical testing was performed by applying vertical compression force to the center of the posteromedial fracture fragment until the load to failure (displacement ≥ 3 mm) was reached, and displacement of the fragment was measured using a motion sensor. The data exhibited normal distribution, and one-way analysis of variance (ANOVA) was used to determine the load to failure, followed by Fisher post hoc Least-Significant Difference (LSD) to correct for multiple comparisons. The statistical analysis demonstrated significantly higher mean load to failure values in the T-shaped plate group compared to both the small dynamic compression plate group and the lag screw group (p < 0.05). However, after conducting further post hoc analysis, the observed significant differences were solely between the LS and TP groups (p = 0.021). These findings suggest that the T-shaped plate represents the most effective method for internally fixing posteromedial tibial plateau fractures.

Resultados post operatorios en pacientes con prótesis total de revisión de cadera mas injerto óseo cadavérico de banco de tejidos en el Hospital de Clínicas en el periodo 2017 al 2020 / Postoperative results in patients with total hip revision arthroplasty and cadaveric bone graft of tissue bank at the Hospital de Clínicas in the period 2017 to 2020

Introducción: La artroplastia total de cadera de revisión junto con la utilización de injerto óseo cadavérico de banco de tejidos es una alternativa de tratamiento eficaz ante los procedimientos de reemplazo con déficit óseo femoral o acetabular. El presente estudio, analizó los resultados post operatorios en pacientes intervenidos quirúrgicamente en el Hospital de Clínicas. Materiales y métodos: Estudio descriptivo. Muestreo no probabilístico de casos consecutivos atendidos en la Cátedra de Ortopedia y Traumatología de la Facultad de Ciencias Médicas (U.N.A). Fueron captados pacientes con indicación de artroplastia total de cadera de revisión (ATCR) más injerto óseo cadavérico de banco de tejidos, entre diciembre 2017 - octubre 2020, previo consentimiento informado. Se relevaron datos cuya caracterización fue posible mediante un instrumento establecido previamente, ingresado en base Excel. Resultados: 12 pacientes con déficit óseo femoral y acetabular han sido tratados con artroplastia total de cadera de revisión más injerto óseo cadavérico de banco de tejidos, en donde además de la funcionalidad y a través de seguimientos radiológicos se ha determinado la osteointegración total de los aloinjertos. La relación masculino-femenina fue 1/1, siendo el diagnóstico preoperatorio para la colocación de la prótesis de revisión más injerto óseo cadavérico de banco de tejidos el aflojamiento séptico en un 75%. El motivo de consulta más frecuente fue dolor y la secreción y el tiempo quirúrgico fue en promedio de 116 minutos. Conclusión: La artroplastia total de cadera de revisión más aloinjerto presenta óptimos resultados en relación a la osteointegración total y funcionalidad.

Introduction: Revision total hip arthroplasty with use of cadaveric bone graft is an effective treatment for replacement procedures in patients with bone loss femoral or acetabular. The present study analyzed the postoperative results in patients who underwent surgery at the Hospital de Clínicas. Materials and methods: Descriptive study. Non-probabilistic sampling of consecutive cases treated at the Department of Orthopedics and Traumatology of Hospital de Clínicas. Data of patients with indication for revision total hip arthroplasty plus cadaveric bone graft from a tissue bank with prior informed consent,were analyzed between December 2017 and October 2020. Results: 12 patients with femoral and acetabular bone deficits have been treated with revision total hip arthroplasty plus cadaveric bone graft from a tissue bank. A radiological and functional follow up was made. The male-female ratio was 1/1, with the preoperative diagnosis for placement of the revision prosthesis plus cadaveric bone graft,from the tissue bank,was septic loosening in 75%. The most frequent symptom was pain, all revision total hip arthroplasties were performed through a posterior approach, and the surgical time was an average of 116 minutes,using a later approach in all cases.Two intraoperative fracture was presented, and were resolved. Conclusion: Revision total hip arthroplasty plus allograft presents optimal results in relation to total osseointegration and functionality.

Does bone compaction around the helical blade of a proximal femoral nail anti-rotation (PFNA) decrease the risk of cut-out?: A subject-specific computational study.

OBJECTIVES: Because of the contradictory body of evidence related to the potential benefits of helical blades in trochanteric fracture fixation, we studied the effect of bone compaction resulting from the insertion of a proximal femoral nail anti-rotation (PFNA). METHODS: We developed a subject-specific computational model of a trochanteric fracture (31-A2 in the AO classification) with lack of medial support and varied the bone density to account for variability in bone properties among hip fracture patients. RESULTS: We show that for a bone density corresponding to 100% of the bone density of the cadaveric femur, there does not seem to be any advantage in using a PFNA with respect to the risk of blade cut-out. On the other hand, in a more osteoporotic femoral head characterised by a density corresponding to 75% of the initial bone density, local bone compaction around the helical blade provides additional bone purchase, thereby decreasing the risk of cut-out, as quantified by the volume of bone susceptible to yielding. CONCLUSIONS: Our findings indicate benefits of using a PFNA over an intramedullary nail with a conventional lag screw and suggest that any clinical trial reporting surgical outcomes regarding the use of helical blades should include a measure of the femoral head bone density as a covariable.