Staged bone grafting following placement of an antibiotic spacer block for the management of segmental long bone defects

Segmental long bone defects resulting from injury or surgical intervention are difficult problems to manage. Amputation, external fixators, vascularized fibular grafts, acute limb shortening, and various quantities of allograft and autograft have historically been the mainstays of treatment. Recently, the use of osteoinductive substances such as recombinant bone morphogenic proteins, and osteoconductive scaffolds such as calcium phosphate have found use in the treatment of these clinical situations. More recently, Masquelet described the use of a cement spacer placed within the osseous void followed by staged bone grafting within the induced biomembrane formed around the spacer as a potential treatment strategy to manage these large defects.This article describes a series of 11 patients for which we used this technique of staged bone grafting following placement of an antibiotic spacer to successfully manage osseous long bone defects ranging from 4 to 15 cm. The limbs were stabilized and aligned at the time of initial spacer placement with a plate and screw construct, intramedullary nail, or fine wire fixator. Osteoinductive substances including bone morphogenic protein-2 and platelet rich concentrate were used in addition to allograft to improve bony healing. In our series, osseous consolidation and full weight bearing was achieved in 10 of 11 patients. Two patients developed heterotopic ossification. There was 1 non-union and 1 infection, which occurred in the same patient. Staged bone grafting within an induced biomembrane created after the use of a cement spacer is a reasonable option in the management of both acute and delayed segmental long bone defects.     

Comparison of different grid of tags detection methods in tagged cardiac MR imaging

Purpose  

Non-invasive imaging assessment of cardiac function is important in cardiovascular disease diagnosis, especially for evaluation of local cardiac motion. Tagged cardiac MRI has been developed for this purpose, but evaluation of the results requires quantification and automation.     

Impact of radiofrequency ablation on PBMC subpopulation in patients with renal cell carcinoma

Purpose

With the development of diagnostic techniques, renal cell carcinoma (RCC) is currently diagnosed in earlier stages, allowing the introduction of less invasive techniques in its management. One of the most promising new treatment methods is based on the utilization of high temperature created by radiofrequency current circulating around the needle probe introduced into the tumor. Besides the direct destruction of the cancer tissue, the treatment may induce immunologic reaction to tumor antigens released from destroyed tumor cell. This paper describes changes observed in the peripheral blood lymphocyte population after radiofrequency ablation (RFA) of RCC.

Methods

Blood was tested before, and 2, 4, and 6 weeks after the RFA in 6 patients with RCC for the proportions and numbers of CD3⁺, CD3⁺HLA-DR⁺, CD3⁺CD4⁺, CD3⁺CD8⁺, and CD56⁺CD16⁺ cells. The blood was stained with fluorochrome-conjugated monoclonal antibodies and percentages of cells expressing various markers were determined by flow cytometry.

Results

In all patients, the changes were most pronounced 2 weeks after the procedure. The proportion of CD4⁺ and CD8⁺ lymphocytes were changed. In 1 patient, an increase in both CD4⁺ and CD8⁺ cells was observed. In 5 out of 6 patients, the proportion of activated (DR⁺) cells was increased over the whole follow-up period with the highest values in the second week after RFA. The percentage of the CD56⁺CD16⁺ was decreased in most of the patients.

Conclusions

Our study confirms that in the majority of patients, RFA of the renal tumors causes significant changes in the proportion of the peripheral immune cells. We suggest that the results presented in this article shows the necessity for further studies.     

Autobiographical memory in semantic dementia: New insights from two patients using fMRI

Episodic autobiographical memory (EAM) consists of personal events embedded within a specific spatiotemporal context. Patients with semantic dementia (SD) generally show preserved recent EAMs, but a controversy remains concerning their ability to retrieve remote ones. Only one fMRI study examined remote autobiographical memory in SD through a longitudinal case study (Maguire, Kumaran, Hassabis, & Kopelman, 2010). Here, we propose a cross-sectional study to test the hippocampo-neocortical up-regulation hypothesis, through a multimodal approach (gray matter volume, activation, connectivity analyses), directly comparing recent and remote autobiographical memory retrieval and collecting data to asses phenomelogical re-experiencing. EAM retrieval recruits a distributed network of brain regions, notably the hippocampus which is shown to be atrophied in SD, although some studies report no hippocampal atrophy in SD. Using fMRI, we examined recent and remote EAM retrieval in two SD patients with different profiles of hippocampal atrophy, compared to 12 healthy elders (HE). JPL presented severe bilateral hippocampal atrophy, while EP showed sparing of both hippocampi. Behaviourally, JPL was impaired at retrieving EAMs from both life periods and showed poorer use of visual mental imagery than HE, while EP retrieved memories which were as episodic as those of HE for both periods and relied on greater use of visual mental imagery than HE. Neuroimaging results showed that, for JPL, hyperactivations of the residual hippocampal tissue and of frontal, lateral temporal, occipital and parietal cortices did not efficiently compensate his autobiographical memory deficit. EP however presented hyperactivations in similar neocortical regions which appeared to be more efficient in compensating for atrophy elsewhere, since EP's EAM retrieval was preserved. Functional connectivity analyses focusing on the hippocampus showed how the residual hippocampal activity was connected to other brain areas. For JPL, recent autobiographical retrieval was associated with connectivity between the posterior hippocampus and middle occipital gyrus, while for EP, connectivity was detected between the anterior hippocampus and numerous regions (medial temporal, occipital, temporal, frontal, parietal) for both recent and remote periods. These findings suggest that intensification of hippocampal atrophy in SD strongly affects both recent and remote autobiographical recollection. Up-regulation of neocortical regions and functional hippocampal–neocortical connectivity within the autobiographical network may be insufficient to compensate the lifelong episodic memory deficit for patients with extensive hippocampal atrophy.     

Implanted bisphosphonates in bone cement affect bone markers in rat serum

Purpose

Bisphosphonates (BPs) are antiresorptive drugs that provide important effects on bone turnover. The key to the high efficiency of BPs is their affinity for bone tissue, and their chemical structure provides their molecular mechanism of action. BPs are widely used to treat a variety of diseases that cause excess bone resorption, such as bone metastasis, hypercalcaemia due to malignancy and Paget’s disease. The goal of this study was to assess whether the bisphosphonate (Pamifos®) present in bone cement has any effect on bone turnover. In this paper, we present changes in cytokine levels in the serum of rats treated surgically.

Methods

Research was performed on 40 adult male Wistar rats. The rats were divided into four groups: two control groups (A, B) and two experimental groups (C, D). Bone in rats in the experimental groups was implanted with BP-enriched cement, whereas bone in control-groups rats was implanted with clean cement (without BPs).

Results

We found a higher concentration of tumour necrosis factor alpha (TNF-α) three weeks after surgery in rats implanted with BP-enriched cement compared with rats implanted with clean cement. After six weeks of treatment, TNF-α levels decreased significantly in rats treated with BP-enriched cement, whereas the control group experienced an increase in TNF-α. The concentration of osteoprotegerin ligand (OPG) was higher in rats with BP implants. We found high levels of receptor activator of nuclear factor kappa-B ligand (RANKL) in rats after implantation of cement without BP in both groups.

Conclusions

We conclude that use of bisphosphonate (Pamifos®), which is present in bone cement, has an effect on bone turnover in that BPs stimulate an increase in OPG and a decrease in RANKL in the bone microenvironment and thus may be an important component of mechanisms that reduce bone resorption. Therefore, the use of BP-enriched cement implants appears to be justified.     

Early results of treatment for congenital clubfoot using the Ponseti method

The purpose of this study was to evaluate the early results of the Ponseti method in reducing extensive corrective surgery rates for congenital idiopathic clubfoot in patients treated in Children's Orthopaedic Clinic and Rehabilitation Department Medical University of Lublin between the years 2007-2011. Thirty-five patients with 47 idiopathic clubfeet were followed prospectively while being managed with the Ponseti method. Clubfoot severity was graded with use of the Dimeglio system. The initial correction was achieved, and early results were measured by using Pirani scoring method.