Are our expectations bigger than the results we achieve? A comparative study analysing potential advantages of ankle arthroplasty over arthrodesis

Purpose

Prior studies have reported improved gait performance and kinematics after total ankle arthroplasty (TAR) compared to ankle arthrodesis (AAD). Given these findings, AAD has been primarily considered as a salvage procedure that may lead to adjacent joint degeneration.

Methods

A total of 101 TAR and 40 screw arthrodeses were enrolled in a retrospective study with a prospectively designed follow-up examination that included gait analysis and outcome assessment with the AOFAS hindfoot score and FAOS questionnaire.

Results

Significant asymmetry in gait and reduced range of motion compared to normal remained after both procedures. Subjective outcome improved after both procedures, and pain was significantly better after TAR. Limited functional gains after TAR and joint degeneration to the same degree after both procedures was seen in the mid-term. Hindfoot fusion seemed to have a greater impact on postoperative function than ankle arthrodesis.

Conclusion

Considering only minor functional gains of TAR compared to AAD the implantation of current TAR designs in large patient series may be questioned.     

Customised osteotomy guides and endoprosthetic reconstruction for periacetabular tumours

Purpose

We sought to analyse clinical and oncological outcomes of patients after guided resection of periacetabular tumours and endoprosthetic reconstruction of the remaining defect.

Methods

From 1988 to 2008, we treated 56 consecutive patients (mean age 52.5 years, 41.1 % women). Patients were followed up either until death or February 2011 (mean follow up 5.5 years, range 0.1–22.5, standard deviation ± 5.3). Kaplan–Meier analysis was used to estimate survival rates.

Results

Disease-specific survival was 59.9 % at five years and 49.7 % at ten and 20 years, respectively. Wide resection margins were achieved in 38 patients, whereas 11 patients underwent marginal and seven intralesional resection. Survival was significantly better in patients with wide or marginal resection than in patients with intralesional resection (p = 0.022). Survival for patients with secondary tumours was significantly worse than for patients with primary tumours (p = 0.003). In 29 patients (51.8 %), at least one reoperation was necessary, resulting in a revision-free survival of 50.5 % at five years, 41.1 % at ten years and 30.6 % at 20 years. Implant survival was 77.0 % at five years, 68.6 % at ten years and 51.8 % at 20 years. A total of 35 patients (62.5 %) experienced one or more complications after surgery. Ten of 56 patients (17.9 %) experienced local recurrence after a mean of 8.9 months. The mean postoperative Musculoskeletal Tumor Society (MSTS) score was 18.1 (60.1 %).

Conclusion

The surgical approach assessed in this study simplifies the process of tumour resection and prosthesis implantation and leads to acceptable clinical and oncological outcomes.     

Quality of Life After Surgical Treatment of Early Barrett’s Cancer: A Prospective Comparison of the Ivor-Lewis Resection Versus the Modified Merendino Resection

Introduction

The Merendino (MER) procedure has been evaluated as an alternative to transthoracic esophageal resection (TER) for early stage Barrett’s carcinoma. Apart from reducing morbidity and mortality, improvements concerning postoperative health-related quality of life (HRQL) have been postulated. The aim of our study was to compare HRQL between these procedures.

Materials and methods

Between July 2000 and July 2007, 117 patients with early Barrett’s carcinoma underwent surgery. Patients with tumor recurrence were excluded from the study. HRQL was assessed 1 and 2 years after surgery using the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Core Questionnaire (EORTC-QLQ-C30) and the QLQ-OES18 module. Patients recently diagnosed with early Barrett’s carcinoma served as controls. Symptoms that showed a difference of more than ten between the control and the study groups were considered clinically relevant and were tested for significant differences between the study groups using the Mann–Whitney U test (p < 0.05).

Results

The response rates for the questionnaires ranged between 70 and 93 %. In the MER group, more items reflected a clinical relevant impairment of HRQL than in the TER group. Significant complaints in the MER group included nausea/vomiting, appetite loss, local pain, difficulties with social eating, and choking. Moreover, we found a significant restriction concerning global health and emotional and social functioning in this group 1 year after surgery. 2 years postoperatively, hardly any differences between the operative techniques could be detected. The only symptom in favor of the MER procedure was a better dysphagia score postoperatively.

Conclusion

Our study suggests that MER procedure is not superior to subtotal esophagectomy with regard to HRQL.     

Impact of the Reconstruction Method on Delayed Gastric Emptying After Pylorus-Preserving Pancreaticoduodenectomy: A Prospective Randomized Study

Background

Delayed gastric emptying (DGE) is of considerable concern in patients undergoing pylorus-preserving pancreaticoduodenectomy (PPPD). Prolonged hospital stay, increased cost, and decreased quality of life add on to interventions needed to treat DGE. This study was conducted to determine if performing duodenojejunostomy via the antecolic rather than the retrocolic route improved incidence of DGE.

Methods

Patients undergoing PPPD between April 2007 and November 2009 were randomized for either antecolic or retrocolic reconstruction of the duodenojejunostomy. DGE was then assessed by clinical criteria on postoperative day (POD) 10. A paracetamol absorption test was also administered with a liquid meal, and serial plasma levels of intestinal peptides were measured.

Results

Overall, 64 patients were amenable for analysis: 36 in the antecolic group and 28 in the retrocolic group. The incidences of DGE on POD 10 were 17.6 and 23.1 % (antecolic vs. retrocolic, respectively) (p = 0.628). The two groups did not differ in regard to their median (interquartile range) postoperative hospital length of stay [13.0 (10.0–17.5) vs. 12.5 (11.0–17.0) days; p = 0.446], time to regular diet [5 (5–7) vs. 5 (4–6) days; p = 0.353], or morbidity (52.9 vs. 50.0 %; p = 0.777). The median length of nasogastric tube decompression was similar in the two groups [4 (3–7) vs. 3 (3–5) days; p = 0.600]. Levels of paracetamol and glucagon-like peptide-1 were markedly decreased in patients with DGE.

Conclusions

Antecolic reconstruction after PPPD does not improve the occurrence/the incidence of DGE and is similar to retrocolic reconstruction with regard to secondary outcome parameters.     

Krankheitsspezifische Lebensqualität im Vergleich dreier operativer Therapien der V.-saphena-magna-Varikose

Background

Endoluminal thermic ablation of varicosis of the great saphenous vein (GSV) is often said to be connected to a better perioperative quality of life (QOL). However, in the clinical experience of the authors, this hypothesis cannot be generally applied. Results contesting this postulate can also be found in the literature. However, the majority of studies have inadequate statistical power.

Objectives

In a prospective randomized controlled intervention trial, crossectomy (high ligation)/stripping (C/S), endoluminal laser therapy (laser) and a combination of both (laser/C) were compared in terms of phlebological disease-related QOL. Patients’ QOL was assessed using a standardized questionnaire (Freiburg Life Quality Assessment-vein, FLQA-v).

Materials and methods

The FLQA-v was presented to 449 patients 2 months after surgery. The FLQA-v comprises 81 questions in the categories physical ailments, everyday life, social life, psychological wellbeing, therapy, satisfaction and occupation. The minimum number of answers to items of each scale was 75?%. The FLQA-v scales were evaluated in terms of mean, standard deviation (SD) and 95?% confidence intervals (CI). The different therapeutic strategies were compared in terms of both the FLQA-v scales and a global score.

Results

The FLQA-v was completed by 343 patients. With mean values lower than 2.5, the scales indicated good QOL. The average global score of patients in the C/S group was 1.7?±?0.5 (95?% CI 1.6–1.8), in the laser group 1.7?±?0.4 (95?% CI 1.6–1.7) and in the laser/C group 1.8?±?0.5 (95?% CI 1.7–1.8). Neither the scales nor the global score revealed a statistically significant difference between the three groups (p?=?0.782 physical ailments, p?=?0.706 everyday life, p?=?0.919 social life, p?=?0.523 psychological wellbeing, p?=?0.418 therapy, p?=?0.158 satisfaction and p?=?0.307 global score). The scale occupation was rejected because of >?25?% missing values.

Conclusion

The C/S, laser and laser/C therapeutic strategies all achieved a vast improvement in QOL compared to the preoperative situation. During the perioperative period (up to 2 months), QOL was similar for all strategies. The results are similar to those found in the literature, where, with one exception, no differences between the procedures in terms of QOL were documented, independent of the measurement instrument applied.     

Optimization of Manufacturing Parameters and Tensile Specimen Geometry for Fused Deposition Modeling (FDM) 3D-Printed PETG

Additive manufacturing provides high design flexibility, but its use is restricted by limited mechanical properties compared to conventional production methods. As technology is still emerging, several approaches exist in the literature for quantifying and improving mechanical properties. In this study, we investigate characterizing materials’ response of additive manufactured structures, specifically by fused deposition modeling (FDM). A comparative analysis is achieved for four different tensile test specimens for polymers based on ASTM D3039 and ISO 527-2 standards. Comparison of specimen geometries is studied with the aid of computations based on the Finite Element Method (FEM). Uniaxial tensile tests are carried out, after a careful examination of different slicing approaches for 3D printing. We emphasize the effects of the chosen slicer parameters on the position of failures in the specimens and propose a simple formalism for measuring effective mechanical properties of 3D-printed structures.     

Surface Modifications of Titanium Aluminium Vanadium Improve Biocompatibility and Osteogenic Differentiation Potential

Osteogenic cells are strongly influenced in their behaviour by the surface properties of orthopaedic implant materials. Mesenchymal stem and progenitor cells (MSPCs) migrate to the bone–implant interface, adhere to the material surface, proliferate and subsequently differentiate into osteoblasts, which are responsible for the formation of the bone matrix. Five surface topographies on titanium aluminium vanadium (TiAl₆V₄) were engineered to investigate biocompatibility and adhesion potential of human osteoblasts and the changes in osteogenic differentiation of MSPCs. Elemental analysis of TiAl₆V₄ discs coated with titanium nitride (TiN), silver (Ag), roughened surface, and pure titanium (cpTi) surface was analysed using energy-dispersive X-ray spectroscopy and scanning electron microscopy. In vitro cell viability, cytotoxicity, adhesion behaviour, and osteogenic differentiation potential were measured via CellTiter-Glo, CytoTox, ELISA, Luminex^® technology, and RT-PCR respectively. The Ag coating reduced the growth of osteoblasts, whereas the viability of MSPCs increased significantly. The roughened and the cpTi surface improved the viability of all cell types. The additive coatings of the TiAl₆V₄ alloy improved the adhesion of osteoblasts and MSPCs. With regard to the osteogenic differentiation potential, an enhanced effect has been demonstrated, especially in the case of roughened and cpTi coatings.     

Platelet activation and myocardial necrosis in patients undergoing radiofrequency and cryoablation of isthmus-dependent atrial flutter.

AIMS: Lower platelet activation by cryoenergy compared with radiofrequency (RF) energy was recently demonstrated immediately following ablation procedures of cardiac arrhythmias. Due to the delayed occurrence of cryolesions it is currently unknown, if cryoenergy and RF energy are associated with similar platelet activation and myocardial necrosis in the days after the procedure. METHODS AND RESULTS: We enrolled 38 patients with common atrial flutter undergoing cavotricuspid isthmus ablation with either RF energy (n = 23) or cryoenergy (n = 13). Ten patients undergoing RF ablation and receiving aspirin served as antiplatelet control group. Troponin T and platelet surface protein expression of P-selectin were determined before and immediately after ablation as well as on day 1 and 2 thereafter. Rise in troponin T was amplified after RF ablation (0.50 +/- 0.37 microg/L) when compared with cryoablation (0.24 +/- 0.20 microg/L; P = 0.024). In patients without aspirin, a significant increase in P-selectin expression was observed on day 1 after intervention in RF ablation compared with cryoablation (80 +/- 26 vs. 63 +/- 16 arbitrary units; P = 0.048). Platelet activation was attenuated in patients receiving aspirin. CONCLUSION: Successful ablation of atrial flutter with cryoenergy is associated with less myocardial necrosis and platelet activation compared with ablation with RF energy. Increased platelet activation following RF ablation can be attenuated by concomitant treatment with aspirin.     

Comparison of conventional and transesophageal echocardiography with magnetic resonance imaging for anatomical mapping of thoracic aortic dissection

Thirty-five consecutive patients with clinically suspected aortic dissection were subjected to a dual noninvasive imaging protocol using comprehensive echocardiography and ECG-triggered MRI with multi-slice spin echo and cine sequences in random order. The purpose of this dual imaging study was to compare the diagnostic accuracy of two-dimensional and color-coded Doppler echocardiography using the conventional transthoracic (TTE) and the transesophageal approach (TEE) with magnetic resonance imaging (MRI) for the exact morphologic evaluation and anatomical mapping of the thoracic aorta. The results of each diagnostic method were validated independently against the gold standard of intraoperative findings (n=17), necropsy (n=4) or contrast angiography (n=22).Compared to conventional transthoracic echocardiography both TEE and MRI were more reliable in detecting aortic dissections (TTE vs TEE: p<0.02; TTE vs MRI: p<0.01) and associated epiphenomena. Moreover, the reliability of TTE decreased significantly from proximal to distal segments of the aorta, e.g. from the ascending segment to the arch (p<0.05) and to the descending aorta (p<0.005), whereas the sensitivities of both TEE and MRI were excellent irrespective of the site of dissection. With regard to epiphenomena such as thrombus formation and entry location, MRI emerged as the optimal method for detailed morphologic information in all segments of the aorta. No serious side effects were encountered with either method.Thus, in patients with suspected acute or subacute aortic dissections the echocardiographic assessment should include the transesophageal approach for significant improvement of the moderate sensitivity and specificity of TTE. Both TEE and MRI are non-traumatic, safe and diagnostically accurate to identify and classify acute and subacute dissections of the thoracic aorta irrespective of their location. MRI provides superb anatomical mapping of all type A and B dissections and more detailed information on the site of entry and thrombus formation than TEE. These features of TEE and MRI may render retrograde contrast angiography obsolete in the setting of thoracic aortic dissection and may encourage surgical interventions exclusively on the basis of noninvasive imaging.     

Pre-treatment of peripheral blood progenitor cells with macrophage inflammatory protein-1α induces prolonged survival of early progenitor cells over 6 weeks of long-term culture

It has previously been shown that a combination of macrophage inflammatory protein-1α (MIP-1α) and interleukin (IL)-3 maintained human bone marrow (BM)-derived long-term culture-initiating cells (LTC-IC) for at least 8 weeks in vitro . We investigated colony- and cobblestone area-formation potential of peripheral blood progenitor cells (PBPC) at week 6 of long-term culture (LTC) in the absence of exogenous MIP-1α, but using cells which had been pre-incubated in the presence of MIP-1α for 40 h in liquid culture. The recovery of colony-forming cells (CFC) and cobblestone-area-forming cells (CAFC) after pre-incubation of PBPC with MIP-1α was up to threefold higher ( P  < 0.05, n  =5) than that of untreated controls. These results demonstrate that short-term pre-treatment of PBPC with MIP-1α induces long-lasting survival effects on early PBPC-derived progenitors in vitro .