Impingement of the Sciatic Nerve due to a Protruding Acetabular Cage Rim

Sciatic nerve damage is a well-known complication that occurs in 1.5% of patients after primary total hip arthroplasty and in 8% after revision total hip arthroplasty. Yet when considering re-revision arthroplasty and acetabular cage implantation, incidence and management remain unclear. This case report describes a young female patient with sciatic nerve impingement after acetabular cage implantation. Her primary complaint was shooting sciatic left leg pain, worsening on ambulation and when seated. A complete workup was negative for spinal impingement or infection, and axonal nerve damage was confirmed through nerve conduction studies. The intraoperative findings showed that it was the acetabular cage rim that stretched the sciatic nerve. The rim was adjusted using a diamond burr to provide a specific solution without sacrificing the acetabular anchorage. Postoperative findings showed an excellent return to previous mobility and resolution of pain. This case provides a rare example of sciatic nerve impingement, showing that nerve palsies in the revision total hip arthroplasty setting may require patient-specific solutions.

In Vivo Modulation of Angiogenesis and Immune Response on a Collagen Matrix via Extracorporeal Shockwaves

The effective management of tissue integration and immunological responses to transplants decisively co-determines the success of soft and hard tissue reconstruction. The aim of this in vivo study was to evaluate the eligibility of extracorporeal shock wave therapy (ESWT) with respect to its ability to modulate angiogenesis and immune response to a collagen matrix (CM) for tissue engineering in the chorioallantoic membrane (CAM) assay, which is performed with fertilized chicken eggs. CM were placed on the CAM on embryonic development day (EDD) 7; at EDD-10, ESWT was conducted at 0.12 mJ/mm² with 500 impulses each. One and four days later, angiogenesis represented by vascularized area, vessel density, and vessel junctions as well as HIF-1α and VEGF gene expression were evaluated. Furthermore, immune response (iNOS2, MMP-9, and MMP-13 via qPCR) was assessed and compared between ESWT- and non-ESWT-groups. At EDD-14, the vascularized area (+115% vs. +26%) and the increase in vessel junctions (+751% vs. +363%) were significantly higher in the ESWT-group. ESWT significantly increased MMP-9 gene expression at EDD-11 and significantly decreased MMP-13 gene expression at EDD-14 as compared to the controls. Using the CAM assay, an enhanced angiogenesis and neovascularization in CM after ESWT were observed. Furthermore, ESWT could reduce the inflammatory activity after a latency of four days.

Misdiagnosis of Thoracolumbar Posterior Ligamentous Complex Injuries and Use of Radiographic Parameter Correlations to Improve Detection Accuracy

STUDY DESIGN

Retrospective study.

PURPOSE

To evaluate radiological parameters as indicators for posterior ligamentous complex (PLC) injuries in the case of limited availability of magnetic resonance imaging.

OVERVIEW OF LITERATURE

Traumatic thoracolumbar spinal fractures with PLC injuries can be misdiagnosed on X-rays or computed tomography scans. This study aimed to retrospectively assess unrecognized PLC injuries and evaluate radiographic parameters as indicators of PLC injuries requiring surgery.

METHODS

In total, 314 patients with type A and type B2 fractures who underwent surgical treatment between 2001 and 2010 were included. The frequency of misdiagnosis was reassessed, and radiographic parameters were evaluated and correlated.

RESULTS

The average age of the patients was 51.8 years. There were 225 type A3/A4 and 89 type B2 fractures; 39 of the type B2 fractures (43.8%) had been misdiagnosed as type A fractures. Type B fractures presented with a significantly higher kyphotic wedge angle and Cobb angle and a lower sagittal index (SI) than type A fractures. In addition, the normalized interspinous distance was higher in type B2 fractures. The significant mathematical indicators for PLC injuries were as follows: Cobb angle+kyphotic wedge angle >29°; Cobb angle2 >170°; and vertebral angle/SI >25.

CONCLUSIONS

The results demonstrated that PLC injuries are frequently misdiagnosed. Correlations between certain radiological parameters associated with PLC injuries can be useful indicators of the presence of such injuries requiring surgery.

Severe Pain Due to Paraspinal Abscess Formation in Two Patients with Squamous-Cell Carcinoma of the Head and Neck after Multimodal Treatment Including Cetuximab

BACKGROUND

Patients with squamous-cell carcinoma of the head and neck (SCCHN) on palliative therapy usually have a bad prognosis and suffer from various symptoms. With increasing use of targeted agents in cancer patients at the end of life, the correct assignment of therapy-related symptoms becomes increasingly difficult as cancer-related symptoms usually increase as well.

CASE REPORT

We report on 2 cases of patients with SCCHN who received multimodal treatment including palliative therapy with cetuximab. Both patients developed severe thoracic and cervicothoracic pain following treatment. In both cases, extensive paraspinal abscess formation proved to be the underlying cause. One patient was treated conservatively; the other one had to undergo surgical intervention.

CONCLUSIONS

Awareness of multifaceted therapy-related complications is mandatory when patients receive multimodal treatment including targeted therapies. Unexplained pain syndromes in this context should raise suspicions concerning possible infectious complications and should lead to early use of magnetic resonance imaging.

Effect of bone sialoprotein coated three-dimensional printed calcium phosphate scaffolds on primary human osteoblasts

The combination of the two techniques of rapid prototyping 3D-plotting and bioactive surface functionalization is presented, with emphasis on the in vitro effect of Bone Sialoprotein (BSP) on primary human osteoblasts (hOBs). Our primary objective was to demonstrate the BSP influence on the expression of distinctive osteoblast markers in hOBs. Secondary objectives included examinations of the scaffolds' surface and the stability of BSP-coating as well as investigations of cell viability and proliferation. 3D-plotted calcium phosphate cement (CPC) scaffolds were coated with BSP via physisorption. hOBs were seeded on the coated scaffolds, followed by cell viability measurements, gene expression analysis and visualization. Physisorption is an effective method for BSP-coating. Coating with higher BSP concentrations leads to enhanced BSP release. Two BSP concentrations (50 and 200 μg/mL) were examined in this study. The lower BSP concentration (50 µg/mL) decreased ALP and SPARC expression, whereas the higher BSP concentration (200 μg/mL) did not change gene marker expression. Enhanced cell viability was observed on BSP-coated scaffolds on day 3. hOBs developed a polygonal shape and connected in an intercellular network under BSP influence. Quantitative cell morphology analyses demonstrated for BSP-coated CPCs an enhanced cell area and reduced circularity. The strength of the above-mentioned effects of BSP-coated scaffolds in vivo is unknown, and future work is focusing on bone ingrowth and vascularization in vivo. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2565-2575, 2018.

IFNGR1 single nucleotide polymorphisms in rheumatoid arthritis

On the basis of their biological function, potential genetic candidates for susceptibility to rheumatoid arthritis can be postulated. IFNGR1, encoding the ligand-binding chain of the receptor for interferon gamma, IFNgammaR1, is one such gene because interferon gamma is involved in the pathogenesis of the disease. In the coding sequence of IFNGR1, two nucleotide positions have been described to be polymorphic in the Japanese population. We therefore investigated the association of those two IFNGR1 single nucleotide polymorphisms with rheumatoid arthritis in a case-control study in a central European population. Surprisingly, however, neither position was polymorphic in the 364 individuals examined, indicating that IFNGR1 does not contribute to susceptibility to rheumatoid arthritis, at least in Caucasians.

Association of theIL4R single-nucleotide polymorphism I50V with rapidly erosive rheumatoid arthritis

OBJECTIVE

To examine whether single-nucleotide polymorphisms (SNPs) of the interleukin-4 receptor gene IL4R influence susceptibility to, or radiographic progression in, rheumatoid arthritis (RA).

METHODS

The contribution of 2 SNPs (I50V and Q551R) in the coding region of IL4R to RA susceptibility was analyzed by allele-specific polymerase chain reaction in a case-control study of 471 RA patients and 371 healthy controls. Patients with available radiographs of the hands and feet obtained 2 years after disease onset (n = 302) were stratified retrospectively according to radiologic outcome into an erosive and a nonerosive group to evaluate the association between IL4R SNPs and disease progression.

RESULTS

No differences in the genotype and allele frequencies of the I50V or Q551R SNPs were identified between the RA patients and healthy controls. In contrast, significant differences in the distribution of I50V IL4R SNP genotypes between patients with erosive and nonerosive disease were observed (chi2 = 15.68, P = 0.0004). Bone erosions at 2 years after disease onset were present in 68.1% of patients homozygous for the V50 allele compared with 37.0% of patients homozygous for the I50 allele (odds ratio 3.86, P < 0.0001). This association was independent of individual factors previously associated with severe disease, such as rheumatoid factor or the HLA-DR shared epitope. On a cellular level, the V50 allele conferred significantly reduced responsiveness to interleukin-4, providing a possible mechanism for the association of the I50V IL4R polymorphism with early erosions in RA.

CONCLUSION

Our data identify the I50V IL4R SNP as a novel genetic marker in RA, showing high predictive value for early joint destruction.