Repeated Ct-based Hounsfield Unit Measurements as a Proxy Measure of Intercorporal Bone Graft Remodelling Towards Spinal Fusion; a Feasibility Study.

Background: There is a lack of knowledge about the biological process of intercorporal bone graft remodelling towards successful lumbar spine fusion with bridging vital bone between two adjacent vertebrae. Hounsfield Units (HU) highly correlate with Bone Mineral Density (BMD) and changes in HU may be valuable as proxy measure to monitor ongoing fusion. The aims of this study were to explore the feasibility to quantify BMD changes in the intercorporal bone graft after spinal fusion on consecutive CT-scans, and to explore whether trends in the individual changes in HU over time may serve as a proxy measure for successful fusion or non-fusion.Methods: A retrospective case series was conducted using available one-year and two-year CT-data from patients after posterior lumbar interbody fusion surgery. First, a standardized measuring procedure was developed, incorporating internal phantomless calibration, to establish the HU values of the grafted region of interest using consecutive CT-slices. Subsequently, changes in the participants’ bone graft HU over time between their first and second year after surgery were explored.Results: Between one and two years after surgery, seven out of nine (78%) participants showed an increase in their bone grafts’ HU, ranging from 3% to 41%. In two participants HU-values decreased 14% and 32%, respectively. The intraobserver reliability of the HU measuring procedure was excellent (ICC 0.93 (95% confidence interval 0.91 to 0.95)).Conclusion: The majority (78%) of participants in the current study showed increases in their bone graft HU, which suggests ongoing bone graft remodelling towards lumbar fusion. This result corresponds with the established percentages of achieved rigid bony fusion after lumbar spinal fusion surgery reported in the literature. Thus, prospective follow-up of CT-based HU measurements may have potential as diagnostic measure to monitor bone graft remodelling in time and trends may predict successful fusion or non-fusion. The measurement procedure developed in this study, using internal phantomless calibration, showed excellent intraobserver reliability and merits further study in larger patient numbers.

Safety and efficacy of a novel retrograde route for femoral bone graft harvesting by Reamer-Irrigator-Aspirator: a pilot study on 24 patients

Background The Reamer–Irrigator–Aspirator system was initially developed to reduce fat embolism and thermic necrosis during reamed intramedullary nail fixation of femoral shaft fractures. Currently, this system is used in extended applications including accessing large volume of autologous bone graft, as alternative for iliac crest harvesting. Antegrade femoral bone graft harvesting using the Reamer-Irrigator-Aspirator system is considered the standard technique. The aim of our study is to evaluate the efficacy (bone graft volume) and the complications (blood loss, postoperative pain, and incidence of iatrogenic fractures) of the Reamer–Irrigator–Aspirator system through the retrograde femoral route in a series of patients with post-traumatic bone defects or nonunions. Methods A non-controlled single center retrospective observational cohort study was conducted in a level1 trauma center to evaluate all patients who were treated using the RIA system. Between November 2015 and May 2019, 24 patients (8 women and 16 men; mean age: 41 years [range 27–55 years]) with bone defects or nonunions underwent bone graft harvesting using the Reamer–Irrigator–Aspirator system through retrograde femoral route. Postoperative pain, complications, and bone graft volume were analyzed. Inclusion criteria was patients older than 18 years with a diagnosis of post-traumatic bone defect or associated tibial or femoral nonunion, with minimum 6-months follow, treated using the RIA. We hypothesized that the retrograde route of the RIA system is a safe and efficacious method for bone harvesting. Results The average volume of collected graft was 45 cc (range 30–60 cc). In 83% of the cases, bone grafting was sufficient, while in 17% it was necessary to add iliac crest bone graft to completely fill the bone defect. A mean drop in postoperative hemoglobin of 4.1 g / dL (range 0.5–6.0 g / dL) was evidenced. In 4 cases (33%), a unit of packed red blood cells was required. Regarding postoperative pain, visual analogue scale after 3 months postoperatively was 1.6 in average. After 6 months, the value has decreased to 0.4. There were no perioperative or postoperative complications at 6-month follow-up. Conclusion In this limited case series, large volumes of bone graft were harvested using the retrograde route of the RIA system and there were no intra-/ postoperative complications observed at 6-month follow-up. Therefore this novel technique appears safe and efficacious. However, it’s important to highlight that future prospective controlled studies are necessary to validate the insights from this pilot study.

Secondary alveolar bone graft in incomplete unilateral pre-foramen fissure: case report

Cleft lip and palate is one of the most common facial deformities. During embryonic life, non-fusion of the maxillary and medial nasal plaques leads to cleft lip and palate. Fissures can produce a range of dental problems in terms of number, size, shape, and position, related to deciduous or permanent dentition. Besides this, the teeth most affected are those located in the fissure area. There are numerous treatment protocols, which, despite the lack of a consensus, start as soon as the child is born, going into adulthood, seeking functional and aesthetic rehabilitation. The surgical phases, lip repair, nasal repair, palatoplasty and alveolar bone grafting, are performed according to age. As for the bone graft, the most used option is the secondary graft, with the autogenous one being the most available. Thus, the objective of this work is to present a clinical case of secondary alveolar bone grafting in a 10-year-old female patient with an incomplete unilateral pre-foramen cleft.

A Surgical Approach to Giant Cell Tumor of Lower End of Tibia with Curettage and Reconstruction by Bone Grafting Harvested from Left Iliac Crest and K-wire Fixation: A Case Report

Introduction: Giant cell tumor (GCT) is a distinctive lesion characterized by the proliferation of multinucleate giant cells in a stroma of mononuclear cells; it is generally seen in skeletally mature individuals. GCT is usually found in the long bones around the knee or in the distal radius but distal end of tibia, proximal humerus, vertebrae of young adults are unusual location. We report a case of GCT of the distal end of tibia, with a secondary aneurysmal bone cyst, in a 26-year-old female. Based on our review of the medical literature, it appears that the occurrence of a GCT along with a secondary aneurysmal bone cyst (ABC) in distal end of tibia is less typical with challenging task for full tumor resection and restoration of ankle function to normal. Case Summary: 26 year old female presented with pain&swelling over left ankle since last six month. Biopsy was suggestive of GCT with ABC of lower third tibia. We managed this case with intralesional curettage using phenol and burr and bone graft harvested from left iliac crest for reconstruction of defect along with kwire fixation to achieve optimum anatomical restoration. Conclusion: In cases of GCT, the management depends upon the various factors such as site, age, involvement of the bone, extent of bone involvement and whether there is articular involvement or not. Here Intra-articular GCT is managed with extended intralesional curettage with phenol. Bone graft plays a role of agent for reconstruction of the defect and kwire for anatomical reduction.

Correction: Ou et al. Bone Healing and Regeneration Potential in Rabbit Cortical Defects Using an Innovative Bioceramic Bone Graft Substitute. Appl. Sci. 2020, 10, 6239

In the original publication, there was a mistake in Figure 2a as published [...]