3D analysis of Osteosyntheses material using semi-automated CT segmentation: a case series of a 4 corner fusion plate.

BACKROUND: Scaphoidectomy and midcarpal fusion can be performed using traditional fixation methods like K-wires, staples, screws or different dorsal (non)locking arthrodesis systems. The aim of this study is to test the Aptus four corner locking plate and to compare the clinical findings to the data revealed by CT scans and semi-automated segmentation. METHODS: This is a retrospective review of eleven patients suffering from scapholunate advanced collapse (SLAC) or scaphoid non-union advanced collapse (SNAC) wrist, who received a four corner fusion between August 2011 and July 2014. The clinical evaluation consisted of measuring the range of motion (ROM), strength and pain on a visual analogue scale (VAS). Additionally, the Disabilities of the Arm, Shoulder and Hand (QuickDASH) and the Mayo Wrist Score were assessed. A computerized tomography (CT) of the wrist was obtained six weeks postoperatively. After semi-automated segmentation of the CT scans, the models were post processed and surveyed. RESULTS: During the six-month follow-up mean range of motion (ROM) of the operated wrist was 60°, consisting of 30° extension and 30° flexion. While pain levels decreased significantly, 54% of grip strength and 89% of pinch strength were preserved compared to the contralateral healthy wrist. Union could be detected in all CT scans of the wrist. While X-ray pictures obtained postoperatively revealed no pathology, two user related technical complications were found through the 3D analysis, which correlated to the clinical outcome. CONCLUSION: Due to semi-automated segmentation and 3D analysis it has been proved that the plate design can keep up to the manufacturers' promises. Over all, this case series confirmed that the plate can compete with the coexisting techniques concerning clinical outcome, union and complication rate.

Reduction Osteotomy of the Prominent Tibial Tubercle After Osgood-Schlatter Disease.

PURPOSE: To evaluate the functional and clinical outcome of a new closing-wedge osteotomy for the prominent tibial tubercle after Osgood-Schlatter disease. METHODS: Between 2010 and 2014, 7 consecutive adults (mean age, 28.6 years; range, 26-35 years) were treated by closing-wedge reduction osteotomy of a painful tibial tubercle. All patients had prior nonsurgical and surgical treatment. Preoperative and postoperative tubercular prominence, Caton-Deschamps index for patellar height, the Kujala Anterior Knee Pain Scale, Lysholm Knee Score as well as visual analog scale score and Tegner activity scores were recorded. RESULTS: Mean follow-up after reduction osteotomy was 31.3 months (27-41 months). The bony prominence of the tibial tubercle was significantly reduced (mean 8 mm, P < .001) and the Caton-Deschamps index was lowered from 1.29 to 1.09 (P < .001). From preoperative to last follow-up, the Kujala Anterior Knee Pain Scale increased from 54.71 preoperative to 84.71 (P < .001); the Lysholm Knee Score improved from 72.42 to 94.14 (P < .001); the Tegner activity score increased from 3.1 to 5.7 (P < .001), whereas the visual analog scale significantly decreased from 5.8 to 1.2 (P < .001). No complications were recorded, and all patients were satisfied with clinical outcome. CONCLUSIONS: Closing-wedge osteotomy of the tibial tubercle effectively reduced the bony prominence after Osgood-Schlatter disease and consecutively improved the outcome in terms of knee pain and function. Thus, we can recommend this procedure in selected patients. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Effects on the Distal Radioulnar Joint of Ablation of Triangular Fibrocartilage Complex Tears With Radiofrequency Energy.

PURPOSE: This cadaver study investigated the temperature profile in the wrist joint and distal radioulnar joint (DRUJ) during radiofrequency energy (RFE) application for triangular fibrocartilage complex resection. METHODS: An arthroscopic partial resection of the triangular fibrocartilage complex using monopolar and bipolar RFE was simulated in 14 cadaver limbs. The temperature was recorded simultaneously in the DRUJ and at 6 other anatomic locations of the wrist during RFE application. RESULTS: The mean temperature in the DRUJ was 43.3 ± 8.2°C for the bipolar system in the ablation mode (60 W) and 30.4 ± 3.4°C for the monopolar system in the cut mode (20 W) after 30 seconds. The highest measured temperature in the DRUJ was 54.3°C for the bipolar system and 68.1°C for the monopolar system. CONCLUSIONS: The application of RFE for debridement or resection of the triangular fibrocartilage complex in a clinical setting can induce peak temperatures that might cause damage to the cartilage of the DRUJ. Bipolar systems produce higher mean temperatures than monopolar devices. CLINICAL RELEVANCE: RFE application increases the mean temperature in the DRUJ after 30 seconds to a level that may jeopardize cartilage tissue.

RFE based chondroplasty in wrist arthroscopy indicates high risk for chrondocytes especially for the bipolar application.

BACKGROUND: The application of radiofrequency energy (RFE) has become widespread for surgical performed chondroplasty especially due to the anticipated sealing effect, however the safety of this procedure in the wrist remains unclear. The purpose of this study was to investigate the subchondral temperature during radiofrequency energy (RFE) application simulating chondroplasty in an arthroscopic setting of the wrist. METHODS: A chondroplasty of the lunate fossa was performed during an arthroscopy setting on 14 cadaver arms using monopolar or bipolar RFE. The temperature was recorded simultaneously from 7 predefined anatomical landmarks. RESULTS: The mean temperature for both application modes did not exceed more than 30°C at all measured points, except for the lunate fossa. The highest subchondral measured peak temperature was 49.35°C (monopolar) and 69.21°C (bipolar) in the lunate fossa. In addition, the temperature decreased for both radiofrequency (RF) devices depending on the distance of the sensors to the RF-probe. CONCLUSION: It remains to be questionable how safe RFE can be used for chondroplasty in wrist arthroscopy under continuous irrigation and constant movement to obtain the desired sealing effect. However, the bipolar device should be applied with more caution since peak temperature in the lunate fossa almost reached 70°C even under continuous irrigation.

Temperature in and around the scapholunate ligament during radiofrequency shrinkage: a cadaver study.

PURPOSE: To investigate whether applied radiofrequency energy (RFE) for shrinkage of the scapholunate interosseus ligament reaches temperatures required for ligament shrinkage while leaving adjacent structures unaffected. METHODS: Standard wrist arthroscopy was performed on 7 pairs of cadaveric limbs with continuous saline irrigation and gravity-assisted outflow through an 18-gauge needle. We subjected 14 scapholunate ligaments to treatment with monopolar (n = 7) or bipolar (n = 7) RFE for ligament shrinkage. Temperature was recorded simultaneously inside the dorsal part of the scapholunate interosseus ligament at a depth of 0.9 ± 0.1 mm and at 6 other sites in and around the wrist because thermal shrinkage starts at 60°C to 65°C. RESULTS: We observed an increase in temperature corresponding to the time of energy application. The highest measured peak temperatures at the scapholunate ligament were 43°C (monopolar) and 32°C (bipolar). Mean temperatures at 30 seconds of application were 29°C ± 7°C (monopolar) and 28°C ± 3°C (bipolar). CONCLUSIONS: Temperatures sufficiently high to induce ligament shrinkage were not reached with either monopolar or bipolar RFE. We did not monitor temperature levels responsible for damage on adjacent cartilage or immediately adjacent capsular tissue in this setting. CLINICAL RELEVANCE: This study suggests that RFE for capsular shrinkage in the wrist is safe but ineffective.

Temperature profile of radiofrequency probe application in wrist arthroscopy: monopolar versus bipolar.

PURPOSE: The purpose of this study was to investigate the changes in temperature during wrist arthroscopy comparing monopolar and bipolar radiofrequency energy (RFE). METHODS: A standard wrist arthroscopy was performed on 14 arms of 7 cadavers without irrigation or with continuous irrigation with 0.9% saline solution and gravity-assisted outflow through an 18-gauge needle. We treated 7 wrists with a bipolar device (VAPR II with 2.3-mm side effect electrodes; DePuy Mitek, Westwood, MA) and 7 wrists with a monopolar device (OPES Ablator for small joints, 45°; Arthrex, Naples, FL). The temperature was recorded simultaneously from 7 predefined anatomic landmarks. RESULTS: We observed an increase in the temperature corresponding to the time of energy application. The highest measured peak temperatures were 52°C (monopolar) and 49.5°C (bipolar) without irrigation. Continuous irrigation led to a significant reduction in the temperature at the site of the energy application. The mean temperature decreased by 7°C for the monopolar system and 5°C for the bipolar system when irrigation was used. For both radiofrequency devices, we found a decrease in the temperature proportional to the distance of the sensors to the radiofrequency probe. CONCLUSIONS: Monopolar and bipolar RFE can be safely used in wrist arthroscopy if a continuous irrigation system is applied and the energy impulse does not exceed 5 to 10 seconds. However, it should be used with great care to avoid local heat damage especially at the cartilage. CLINICAL RELEVANCE: This basic science study was performed to gain data concerning the temperature in wrist arthroscopy and to broaden the knowledge about the risks when using RFE. Furthermore, we sought to control side effects of RFE by finding the best applied form of RFE regarding duration and pulsation (monopolar/bipolar).

Type I collagen nerve conduits for median nerve repairs in the forearm.

PURPOSE: To evaluate patients with median nerve damage in the distal forearm treated with type 1 collagen nerve conduits. METHODS: Nine patients with damage to the median nerve in the distal forearm underwent treatment with a type 1 collagen nerve conduit. The nerve gaps ranged between 1 and 2 cm. An independent observer reexamined patients after treatment at a minimal follow-up of 14 months and a mean follow-up of 21 months. Residual pain was evaluated using a visual analog scale. Functional outcome was quantified by assessing static 2-point discrimination, nerve conduction velocity relative to the uninjured limb, and Disabilities of the Arm, Shoulder, and Hand outcome measure scoring. We also recorded quality of life measures including patients' perceived satisfaction with the results and return to work latency. RESULTS: We observed no implant-related complications. Of 9 patients, 7 were free of pain, and the mean visual analog scale was 0.6. The mean Disabilities of the Arm, Shoulder, and Hand score was 6. The static 2-point discrimination was less than 6 mm in 3 patients, between 6 and 10 mm in 4 patients, and over 10 mm in 2 patients. Six patients reached a status of M4 or higher. Eight patients were satisfied with the procedure and would undergo surgery again. CONCLUSIONS: This study indicates that purified type 1 bovine collagen conduits are a practical and efficacious method for the repair of median nerves in the distal forearm. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Evidence-based topical management of chronic wounds according to the T.I.M.E. principle.

The number of patients suffering from chronic wound healing disorders in Germany alone is estimated to be 2.5-4 million. Therapy related expenses reach 5-8 billion Euros annually. This number is partially caused by costly dressing changes due to non-standardized approaches and the application of non-evidence-based topical wound therapies. The purpose of this paper is to elucidate a straightforward principle for the management of chronic wounds, and to review the available evidence for the particular therapy options. The T.I.M.E.-principle (Tissue management, Inflammation and infection control, Moisture balance, Epithelial [edge] advancement) was chosen as a systematic strategy for wound bed preparation. Literature was retrieved from the PubMed and Cochrane Library databases and subjected to selective analysis. Topical wound management should be carried out according to a standardized principle and should further be synchronized to the phases of wound healing. Despite the broad implementation of these products in clinical practice, often no benefit exists in the rate of healing, when evaluated in meta-analyses or systematic reviews. This insufficient evidence is additionally limited by varying study designs. In case of non-superiority, the results suggest to prefer relatively inexpensive wound dressings over expensive alternatives. Arbitrary endpoints to prove the effectiveness of wound dressings, contribute to the random use of such therapies. Defining rational endpoints for future studies as well as the deployment of structured therapy strategies will be essential for the economical and evidence-based management of chronic wounds.

A sprayable luminescent pH sensor and its use for wound imaging in vivo.

Non-invasive luminescence imaging is of great interest for studying biological parameters in wound healing, tumors and other biomedical fields. Recently, we developed the first method for 2D luminescence imaging of pH in vivo on humans, and a novel method for one-stop-shop visualization of oxygen and pH using the RGB read-out of digital cameras. Both methods make use of semitransparent sensor foils. Here, we describe a sprayable ratiometric luminescent pH sensor, which combines properties of both these methods. Additionally, a major advantage is that the sensor spray is applicable to very uneven tissue surfaces due to its consistency. A digital RGB image of the spray on tissue is taken. The signal of the pH indicator (fluorescein isothiocyanate) is stored in the green channel (G), while that of the reference dye [ruthenium(II)-tris-(4,7-diphenyl-1,10-phenanthroline)] is stored in the red channel (R). Images are processed by rationing luminescence intensities (G/R) to result in pseudocolor pH maps of tissues, e.g. wounds.

Fibroblasts share mesenchymal phenotypes with stem cells, but lack their differentiation and colony-forming potential.

BACKGROUND INFORMATION: Although MSCs (mesenchymal stem cells) and fibroblasts have been well studied, differences between these two cell types are not fully understood. We therefore comparatively analysed antigen and gene profiles, colony-forming ability and differentiation potential of four human cell types in vitro: commercially available skin-derived fibroblasts [hSDFs (human skin-derived fibroblasts)], adipose tissue-derived stem cells [hASCs (human adipose tissue-derived stem cells)], embryonic lung fibroblasts (WI38) and dermal microvascular endothelial cells [hECs (human dermal microvascular endothelial cells)]. RESULTS: hSDFs, hASCs and WI38 exhibited a similar spindle-like morphology and expressed same antigen profiles: positive for MSC markers (CD44, CD73 and CD105) and fibroblastic markers [collagen I, HSP47 (heat shock protein 47), vimentin, FSP (fibroblast surface protein) and αSMA (α smooth muscle actin)], and negative for endothelial cell marker CD31 and haemopoietic lineage markers (CD14 and CD45). We further analysed 90 stem cell-associated gene expressions by performing real-time PCR and found a more similar gene expression pattern between hASCs and hSDFs than between hSDFs and WI38. The expression of embryonic stem cell markers [OCT4, KLF4, NANOG, LIN28, FGF4 (fibroblast growth factor 4) and REST] in hASCs and hSDFs was observed to differ more than 2.5-fold as compared with WI38. In addition, hSDFs and hASCs were able to form colonies and differentiate into adipocytes, osteoblasts and chondrocytes in vitro, but not WI38. Moreover, single cell-derived hSDFs and hASCs obtained by clonal expansion were able to differentiate into adipocytes and osteoblasts. However, CD31 positive hECs did not show differentiation potential. CONCLUSIONS: These findings suggest that (i) so-called commercially available fibroblast preparations from skin (hSDFs) consist of a significant number of cells with differentiation potential apart from terminally differentiated fibroblasts; (ii) colony-forming capacity and differentiation potential are specific important properties that discriminate MSCs from fibroblasts (WI38), while conventional stem cell properties such as plastic adherence and the expression of CD44, CD90 and CD105 are unspecific for stem cells.

Breast cancer cells attract the migration of adipose tissue-derived stem cells via the PDGF-BB/PDGFR-beta signaling pathway.

The origin of vascular cells in tumors is unknown, but it is believed that tumors use cells from the host to build new vessels. To determine whether adipose tissue stem cells (ASCs) could be attracted by cancer cells, we performed migration assays in which ASCs were seeded on a transwell migration system top chamber and tumor-conditioned medium was placed in the bottom chamber. Our data showed that a significant number of ASCs migrated toward the tumor-conditioned medium (p<0.0001), and migration of human ASCs significantly (p<0.0001) increased in response to increased concentrations of recombinant PDGF-BB. In addition, neutralizing antibodies to PDGF receptor (PDGFR)-beta decreased migration of ASCs toward a breast cancer-conditioned medium to the level of serum-free control. These data suggest that tumor cell-derived PDGF-BB is an important factor in governing the microenvironment interaction between tumor cells and local tissue-resident stem cells.

PDGF and bFGF modulate tube formation in adipose tissue-derived stem cells.

Recent evidence indicates that mesenchymal stem cells contribute to tumor angiogenesis through yet undefined mechanisms. In the present study, we investigated the angiogenic properties of human adipose tissue-derived stem cells and the mechanisms involved. Freshly isolated human adipose tissue-derived stem cells were seeded onto wells coated with Matrigel and cultured in endothelial growth medium. Capillary-like tube formation was observed after 18 hours culture. Tube formation was significantly reduced in the presence of antibodies against platelet-derived growth factor receptor beta or basic fibroblast growth factor. Collectively, these data suggest that freshly isolated adipose tissue-derived stem cells have the capacity to differentiate into capillary structures and platelet-derived growth factor and bFGF plays a critical role in this process.

Lipolytic effects of nano particle sized polyenylphosphatidylcholine on adipose tissue: First promising in vitro and in vivo results.

BACKGROUND: Lipolytic injectables for body contouring procedures have been reported for necrotic effects on adipose tissue causing side effects as swelling, pain and hematoma. Deoxycholic acid is widely used as a solvent in lipolytic injectables and is associated with necrosis when applied to cells. A new lipolytic preparation (NWL-10) containing only polyenylphosphatidylcholine in nano particle size, glycerrhizinate and maltose has been reported for its lipolytic action on adipose tissue. However, no data exist whether the NWL-10 mixture is responsible for apoptosis or necrosis in adipose tissue which can be associated with severer side effects as reported for deoxycholic acid preparation. METHODS: 3T3-L1 mouse cells and human adipose tissue derived stem cells were exposed to the NWL-10 mixture and to each ingredient of the mix in order to investigate cytotoxic, lipolytic, necrotic or apoptotic effects. Furthermore, a Balb/C mouse animal model was used to investigate inflammatory responses to NWL-10 by bioluminescence monitoring and histological examination. RESULTS: A high extent of lipolysis was detected for the NWL-10 mixture when applied to both cell types with no cytotoxic effect. Interestingly, low concentration of NWL-10 resulted in necrosis whereas high concentration of NWL-10 showed a certain amount of apoptosis. Application of single ingredients of NWL-10 or various combinations of two component mixtures did not result in any apoptosis or necrosis. In addition, no inflammatory effects of NWL-10 were observed in the mouse model. CONCLUSIONS: The NWL-10 mixture provided promising results regarding lipolysis on adipose tissue with limited apoptosis and necrosis when compared to currently available injectables. These first promising results require further fundamental and more detailed research on essentials for drug approval. NWL-10 has the potential to become a second generation product for future lipolytic injectables.

Bone Crushing in Infected Pseudarthrosis - An Extraordinary Way to Treat Osteomyelitis Caused by Resistant Bacteria.

INTRODUCTION: Osteomyelitis with multiresistant bacteria in non-union following fracture treated with osteosynthesis requires complete removal of infected sequestrum and dead bone. For consecutive bone defects, it is frequently necessary to bridge with a fixator external. The treatment is not only challenging due to reduced bone stock but also characterized by decreased bioavailability of antibiotics. CASE REPORT: We report a two-step-surgery approach to preserve the bone stock using autologous cancellous bone in a bacterial infected non-union for subsequently leg length reconstruction. The 24-year-old male patient from Belarus was admitted to our department with persistent wound secretion and subsequent osteomyelitis of the right femur 3 years after initial surgery, several revisions, and several different antibiotic therapies. Biopsy revealed methicillin-resistant and borderline oxacillin-resistant Staphylococcus aureus. Firstly, the Ilizarov ring fixator was removed and a vigorous debridement was performed by refreshing the pseudarthrosis, removing of sequestrum, and dead bone. Finally, an AO fixator external was applied for 10 weeks combined with appropriate antibiotic treatment followed by 5 weeks antibiotic-free window. The bone defect was stabilized by a long gamma trochanteric nail after removal of the AO fixateurexterne. A wide resection of the fragments was performed and the resected bone tissue was crushed and placed adjacent to the nail. Noteworthy, the biopsies of both re-section sides revealed same germs as detected in initial biopsies. Thus, antibiotics were administered for additional 3 months. Frequent radiographic and clinical controls showed a remodeling of the femur during a period of 3 years and no signs of infection. Subsequently, we restored leg length of 4 cm using a fully implantable motorized lengthening nail. In the end, the patient achieved full weight-bearing with unlimited range of motion in hip and knee. No further germ could be revealed in biopsies. CONCLUSION: In this case report, we used autologous bone from the infected side, crushed, and placed it adjacent to an intramedullary nail. Crushed bone tissue might improve bioavailability of antibiotics when dealing with multiresistant bacteria in non-union healed fracture side. Furthermore, this approach was able to provide new bone formation in a limb resulting in full weight-bearing.

Interaction between extracellular cancer matrix and stromal breast cells.

INTRODUCTION: Stromal-epithelial interactions are fundamental for normal organ development and there is a multitude of evidence that the different components of the microenvironment are also necessary for the maintenance and promotion of the "tumor organ". Deregulated tumor associated extracellular matrix (tECM) is a hallmark of cancer, causing an alteration in the amount and composition of the different components (i.e. proteins, proteoglycans, glycoproteins and polysaccharids) of the ECM. As epithelial-stromal interactions are reciprocal, it is possible that tECM itself is able to initiate tumor development. We therefore established a mouse model to examine the influence of tECM of murine breast cancer on developing breast tissue in mice. MATERIALS AND METHODS: Breast cancer was established in 5 BALB/c mice by subcutaneous injection of 1×106 4T1 cells in 100µl PBS into the left mammary fat pad. The mammary fat pad including the primary tumor was excised after two weeks, decellularised and labelled as tumor extracellular matrix (tECM). Tumor ECM of 4T1 tumors was implanted into the 4th inguinal mammary fat pad of BALB/c mice (n = 5) aged 5 days. After 12 weeks the fourth mammary fat pad including the primary tumor was excised. Tissue was used for paraffin embedding and mouse breast cancer PCR array. Murine breast cancer tissue (BCT) and normal murine breast tissue (BT) served as control. RESULTS: Gene array analysis of 84 breast cancer-specific transcripts revealed that the mammary gland cells which were exposed to tumor ECM (tECM-BT) showed a similarly high overexpression for 22 genes as apparent for breast cancer tissue (BCT). The corresponding scatter plot showed a high agreement in the expression of the examined genes between the mammary gland cells which were exposed to tumor ECM and the breast cancer tissue. DISCUSSION: Our results clearly demonstrate that the tECM is able to shift the gene expression pattern of murine mammary epithelial cells towards that of carcinoma, indicating a role in breast cancer initiation. These data underlines that the acellular component of the tumor (ECM) can lead to a transformation of mammary gland tissue cells. These data show for the first time that the interaction of normal breast tissue cells with tumor ECM leads to an exchange of information and a consecutive overexpression of tumor-specific genes.

Enhanced Resorption of Liposomal Packed Vitamin C Monitored by Ultrasound.

Vitamin C is an essential nutrient for humans and is involved in a plethora of health-related functions. Several studies have shown a connection between vitamin C intake and an improved resistance to infections that involves the immune system. However, the body cannot store vitamin C and both the elevated oral intake, and the intravenous application have certain disadvantages. In this study, we wanted to show a new formulation for the liposomal packaging of vitamin C. Using freeze etching electron microscopy, we show the formed liposomes. With a novel approach of post-processing procedures of real-time sonography that combines enhancement effects by contrast-like ultrasound with a transducer, we wanted to demonstrate the elevated intestinal vitamin C resorption on four participants. With the method presented in this study, it is possible to make use of the liposomal packaging of vitamin C with simple household materials and equipment for intake elevation. For the first time, we show the enhanced resorption of ingested liposomes using microbubble enhanced ultrasound imaging.

Intra-individual comparison of human nasal chondrocytes and debrided knee chondrocytes: Relevance for engineering autologous cartilage grafts.

OBJECTIVE: Implantation of autologous chondrocytes for cartilage repair requires harvesting of undamaged cartilage, implying an additional joint arthroscopy surgery and further damage to the articular surface. As alternative possible cell sources, in this study we assessed the proliferation and chondrogenic capacity of debrided Knee Chondrocytes (dKC) and Nasal Chondrocytes (NC) collected from the same patients. METHODS: Matched NC and dKC pairs from 13 patients enrolled in two clinical studies (NCT01605201 and NCT026739059) were expanded in monolayer and then chondro-differentiated in 3D collagenous scaffolds in medium with or without Transforming Growth Factor beta 1 (TGFß1). Cell proliferation and amount of cartilage matrix production by these two cell types were assessed. RESULTS: dKC exhibited an inferior proliferation rate than NC, and a lower capacity to chondro-differentiate. Resulting dKC-grafts contained lower amounts of cartilage specific matrix components glycosaminoglycans and type II collagen. The cartilage forming capacity of dKC did not significantly correlate with specific clinical parameters and was only partially improved by medium supplemention with TGFß1. CONCLUSIONS: dKC exhibit a reproducibly poor capacity to engineer cartilage grafts. Our in vitro data suggest that NC would be a better suitable cell source for the generation of autologous cartilage grafts.

Challenging Implantation of Hip Prosthesis in a 32-year-old Patient with Kniest Syndrome.

INTRODUCTION: Kniest dysplasia is associated with short body stature (dwarfism) and impairment of the musculoskeletal system due to a mutation in the COL2A1 gene coding for a protein that forms type II collagen. Hip endoprosthesis for patients with Kniest system requires a specific femoral shaft design since the medullar space is limited due to the underlying dysplasia. The Wagner cone stem has shown excellent results. It is especially suitable for patients with small or dysplasic femur. However, no data exist regarding hip endoprosthesis in a patient with Kniest syndrome. CASE REPORT: A 32-year-old female patient with Kniest syndrome presented at our department with a painful pseudarthrosis after femoral valgisation osteotomy 8 years ago. A Wagner cone stem and acetabular roof cup with a cemented Ecofit cup 2M (dual-articulation acetabular cup system) were implanted due to a dysplastic femur with a small medullary space. The Ecofit cup itself is associated with a reduced risk of dislocation. The patient was satisfied with the range of motion after hip endoprosthesis and reported a significant increase in quality of life. The patient is still comfortable with the hip prosthesis at the most recent follow-up 4 years after implantation. Follow-up radiographs over 4 years have not revealed any signs of loosening or migration, and no Trendelenburg sign was reported for the affected side. CONCLUSION: The Wagner cone stem provides a good solution in challenging femora caused by previous osteotomies, fractures, or dysplasia. Additional stability of hip prosthesis can be achieved using a dual articulation acetabular cup system. Furthermore, we applied an attachment tube based on the concept of tumorprosthesis where the abductor muscle group got reattached.

Extent of Inflammation and Foreign Body Reaction to Porous Polyethylene In Vitro and In Vivo.

BACKGROUND/AIM: High-density porous polyethylene (PP) offers possibilities for reconstruction in craniofacial surgery. The purpose of this study was to evaluate the extent of inflammation and foreign body reactions to PP in vitro and in vivo. MATERIALS AND METHODS: Cell attachment, proliferation and expression of inflammatory cytokines were assessed using murine macrophages (RAW 264.7) on two different PP materials in vitro. In vivo, Balb/c mice received PP implants at their dorsum. After sacrifice, samples were analyzed histologically and real-time PCR was used to assess expression of inflammatory cytokines. RESULTS: Cells showed a significantly decreased proliferation (p<0.001) after 48 h and a significantly increased expression of TNF-α (p<0.05) at 24, 48 and 72 h. All animals showed foreign body cell reactions and signs of chronic inflammation. Expression of all but one of the investigated cytokines dropped to non-significant levels after an initial increase. CONCLUSION: Application of porous polyethylene can cause local chronic inflammatory reactions. Although clinical application seems to be immunologically safe, indication and risks should be evaluated carefully when using PP implants.

Tissue engineering for paediatric patients.

The effects of oncological treatment, congenital anomalies, traumatic injuries and post-infection damage critically require sufficient amounts of tissue for structural and functional surgical reconstructions. The patient’s own body is typically the gold standard source of transplant material, but in children autologous tissue is available only in small quantities and with severe morbidity at donor sites. Engineering of tissue grafts starting from a small amount of autologous material, combined with suitable surgical manipulation of the recipient site, is expected to enhance child and adolescent health, and to offer functional restoration for long-term wellbeing. Moreover, engineered tissues based on patient-derived cells represent invaluable models to investigate mechanisms of disease and to develop/test novel therapeutic approaches. In view of these great opportunities, here we introduce the currently limited successful implementation of tissue engineering in paediatric settings and discuss the open challenges in the field. A particular focus is on the specific needs and envisioned strategies in the areas of bone and osteochondral regeneration in children.