Treatment of hand and finger fractures with the Stryker Hand Plating System.

Objectives: 10% of all fractures occur in the fingers and metacarpal region. Early mobilization with preservation of grip function is the goal of any therapy for these injuries. Osteosyntheses with plates are used in complex fractures that do not allow any other treatment. The aim of this retrospective study was to evaluate the performance and safety of the Stryker Hand System. Patients and methods: Between 2010 and 2019, 190 patients underwent surgical treatment with plates for fractures of the fingers and metacarpal region. Of these, 140 operations could be analyzed according to the inclusion criteria based on clinical and radiological parameters. Results: Three-quarters of the patients were male. The mean age at the time of surgery was 39.3±16 years. Falling was the leading cause for hand fractures, and the most common were fractures of the shaft (>52%). More than 15% were complex hand injuries with more than one fractured finger. The majority of patients were healthy non-smokers without systemic diseases and relevant medical history. Conclusion: The Stryker Finger Plates are safe implants with good results that are consistent with those reported in the literature. The trend is also toward stable-angle implants for fracture treatment of the finger, in order to enable the earliest possible functional, safe mobilization. Level of Evidence: Level: IV; outcome-study, retrospective.

Autoantibodies from patients with complex regional pain syndrome induce pro-inflammatory effects and functional disturbances on endothelial cells in vitro.

ABSTRACT: Complex regional pain syndrome (CRPS) is an inadequate local response after a limb trauma, which leads to severe pain and autonomic and trophic changes of the affected limb. Autoantibodies directed against human ß2 adrenergic and muscarinic M2 receptors (hß2AR and hM2R) have been described in CRPS patients previously. We analyzed sera from CRPS patients for autoantibodies against hß2AR, hM2R, and endothelial cells and investigated the functional effects of purified IgG, derived from 13 patients with CRPS, on endothelial cells. Eleven healthy controls, 7 radial fracture patients without CRPS, and 10 patients with peripheral arterial vascular disease served as control subjects. The CRPS-IgG, but not control IgG, bound to the surface of endothelial cells ( P < 0.001) and to hß2AR and hM2R ( P < 0.05), the latter being reversed by adding ß2AR and M2R antagonists. The CRPS-IgG led to an increased cytotoxicity and a reduced proliferation rate of endothelial cells, and by adding specific antagonists, the effect was neutralized. Regarding second messenger pathways, CRPS-IgG induced ERK1/2, p38, and STAT1 phosphorylation, whereas AKT phosphorylation was decreased at the protein level. In addition, increased expression of adhesion molecules (ICAM-1 and VCAM-1) on the mRNA level was induced by CRPS-IgG, thus inducing a pro-inflammatory condition of the endothelial cells. Our results show that patients with CRPS not only develop autoantibodies against hß2AR and hM2R, but these antibodies also interfere with endothelial cells, inducing functional effects on these in vitro, and thus might contribute to the pathophysiology of CRPS.

[Surgical treatment of the ulnar styloid process using an angle-stable hook plate in fractures and symptomatic nonunions]. / Operative Versorgung des Processus styloideus ulnae mittels winkelstabiler Hakenplatte bei Frakturen und symptomatischen Pseudarthrosen.

OBJECTIVE: Anatomical reduction of dislocated fractures using an angle-stable hook plate. Surgical revision of symptomatic nonunions with the aim of bone regeneration. INDICATIONS: Dislocated fractures of the ulnar styloid process with involvement of the ulnar fovea. Combined fractures with instability of the distal radioulnar joint and symptomatic nonunions. CONTRAINDICATIONS: Undisplaced fractures of the ulnar styloid process and asymptomatic nonunions. SURGICAL TECHNIQUE: Dorsoradial access to the distal ulna between the 6th extensor tendon compartment and the tendon of the flexor carpi ulnaris muscle. Exposition of the fracture/nonunion. In case of nonunions, excision and freshening of the fracture ends. Reduction is carried out using the hooks of the plate, if necessary additional attachment of autologous cancellous bone in case of nonunions. Fixation of the plate over the gliding hole and subsequent filling of the angular stable screw holes. POSTOPERATIVE MANAGEMENT: Depending on the accompanying injury, immobilization in a forearm plaster splint for 1-2 weeks. Active movement exercises of the fingers from postoperative day 1, if necessary lymph drainage. After bone development, load build-up under ergotherapy guidance. RESULTS: Bony healing was achieved in 100% of our cases. The surgical treatment of symptomatic nonunions as well as dislocated fractures of the ulnar styloid process using an angle-stable hook plate has proven to be successful.

Long-Term Results of the Modular Physiological Wrist Prosthesis (MPW®) in Patients with Inflammatory Diseases.

The wrist is among the predilection sites of over 90% of cases of rheumatoid arthritis (RA). In advanced cases, total wrist arthroplasty (TWA) is an alternative to arthrodesis. The aim of this study is to present the long-term results of the modular physiological wrist prosthesis (MPW®) and to match them in context with the results of a standard population survey. In a retrospective study with follow-up, patients with an MPW® endoprosthesis were evaluated concerning the clinical and radiological outcome, complications were reviewed (incidence and type), and conversion to wrist fusion was assessed. Patient function measurements included the Mayo wrist score, the patient-specific wrist test, and therefore the DASH score (arm, shoulder, and hand). Thirty-four MPW® wrist prostheses were implanted in 32 patients, including thirty primary implantations and four changes of the type of the endoprosthesis. Sixteen patients (18 prostheses) underwent clinical and radiological follow-up. The average follow-up time was 8.5 years (1 to 16). Poor results of the MPW prosthesis are caused by the issues of balancing with luxation and increased PE wear. Salvage procedures included revision of the TWA or fusion. In successful cases, the flexion and extension movement averaged 40 degrees. The grip force was around 2.5 kg. The common DASH score was 79 points, with limited and problematic joints of the upper extremity. The MPW wrist prosthesis offered good pain relief and functional movement in over 80% of cases. The issues of dislocation and increased PE wear prevent better long-term results, as do the joints affected. A follow-up study with fittings under a contemporary anti-rheumatic therapy with biologicals suggests increasing score results. Type of study/level of evidence: Case series, IV.

Evidence of Prolonged Monitoring of Trauma Patients Admitted via Trauma Resuscitation Unit without Primary Proof of Severe Injuries.

Introductio: Although management of severely injured patients in the Trauma Resuscitation Unit (TRU) follows evidence-based guidelines, algorithms for treatment of the slightly injured are limited. METHODS: All trauma patients in a period of eight months in a Level I trauma center were followed. Retrospective analysis was performed only in patients ≥18 years with primary TRU admission, Abbreviated Injury Scale (AIS) ≤ 1, Maximum Abbreviated Injury Scale (MAIS) ≤ 1 and Injury Severity Score (ISS) ≤3 after treatment completion and ≥24 h monitoring in the units. Cochran's Q-test was used for the statistical evaluation of AIS and ISS changes in units. RESULTS: One hundred and twelve patients were enrolled in the study. Twenty-one patients (18.75%) reported new complaints after treatment completion in the TRU. AIS rose from the Intermediate Care Unit (IMC) to Normal Care Unit (NCU) 6.2% and ISS 6.9%. MAIS did not increase >2, and no intervention was necessary for any patient. No correlation was found between computed tomography (CT) diagnostics in TRU and AIS change. CONCLUSIONS: The data suggest that AIS, MAIS and ISS did not increase significantly in patients without a severe injury during inpatient treatment, regardless of the type of CT diagnostics performed in the TRU, suggesting that monitoring of these patients may be unnecessary.

Treatment of proximal fifth metatarsal fractures with an ulna hook plate.

INTRODUCTION: Fractures of the base of the fifth metatarsal bone present one of the commonest fractures of the metatarsal bones. Conventionally intramedullary screws and tension band wiring have been used as internal fixation methods. Lately hook plates have also served as an alternative fixation method. We hereby report on our experience with the hook plate used in treating fractures of the proximal fifth metatarsal. METHODS: 21 patients treated with the hook plate for proximal fifth metatarsal fractures were assessed clinically and radiologically. RESULTS: Average time to union in primarily treated fractures (n=18) was 7.7 weeks (range 4.5-16 weeks). Average time to return of activities of daily living (ADLs) was 10.3 weeks (range 4.5-37 weeks). The average AOFAS midfoot score was 30.4 preoperatively and 95.2 postoperatively (p<0.01). CONCLUSION: The ulna hook plate presents a suitable and adequate method of osteosynthesis used to primarily treat proximal fifth metatarsal fractures requiring surgical intervention with satisfactory post-operative outcomes.

Peri-Prosthetic Joint Infection after Finger Joint Arthroplasty.

Background: Endoprosthetic treatment of finger joints is an established procedure. However, data on peri-prosthetic finger joint infections (PJI) are rare. The goal of this retrospective study was to assess infection rates and treatment outcomes after PJI of the finger joints. Methods: Between 1984 and 2014, 1,195 finger joints (978 metacarpal and 217 proximal interphalangeal [PIP] joints) in 518 patients were treated. A retrospective record analysis was conducted. Besides demographic data, infection rates, types of revision surgery, and treatment outcomes were evaluated. Treatment strategies changed during the treatment period. Routinely assessed patient-reported outcome measures, namely the QuickDASH score, visual analogue scale (VAS), an everyday function score (activities of daily living; ADL), and an adapted Clayton score, were compared. Results: In 36 finger joints of 30 patients, a post-operative peri-prosthetic infection could be identified (3%). Infections occurred on average 3.8 years after arthroplasty. For meta-carpal phalangeal (MCP) joints, the best clinical outcomes could be observed after a two-stage revision procedure (QuickDASH score 86). Arthrodesis performed in a one-stage procedure achieved favorable outcomes in PIP joints (QuickDASH score 89). Re-infection mandating revision surgery occurred in seven joints in five patients (7/36; 19.4%). In 25 patients with 29 finger joints, there was no re-infection and no need for revision. Conclusion: Peri-prosthetic infection of finger joint prostheses occurs in approximately 3% of all cases, which is a higher rate than in the more common hip and knee procedures. For MCP joint revision surgery, a two-stage procedure seems to be the best treatment choice. For PIP joint revision, a single-stage revision with arthrodesis in a functional position achieves a good outcome.

Computed tomography for managing periprosthetic femoral fractures. A retrospective analysis.

BACKGROUND: Periprosthetic fractures (PPF) present a common cause for revision surgery after arthroplasty. The choice of performing either an osteosynthesis or revision arthroplasty depends on the orthopedic implant anchored and loosening. Standard diagnostics include x-ray imaging. CT is usually performed to confirm implant loosening in case of ambiguous diagnosis on standard x-ray imaging. This study aimed to examine the role of CT as a diagnostic modality and its implications for treatment planning and outcome. METHODS: Patients treated for PPF from January 2010 to February 2018 were included. X-ray and CT reports were analyzed to assess implant loosening. The planning for surgery and the final surgical treatment were evaluated. In addition, patient characteristics were analyzed and compared between patients with and without additional CT as a preoperative diagnostic procedure. RESULTS: Seventy-five patients were eligible for the study. X-ray imaging was performed in 90.7% of cases. CT was performed in 60% of the cases as part of the preoperative diagnostic. A clear statement on implant stability or loosening could not be made in 69.1% after X-ray imaging and in 84.4% following CT imaging. Revision arthroplasty for loosened femoral prosthesis components was necessary in 40% of cases. No difference could be determined comparing patients with X-ray imaging to those with X-ray and additional CT. In both groups, operative treatment did not deviate from the preoperative planning. DISCUSSION: In two thirds of the conventional radiographic findings, no reliable evaluation of implant loosening was possible in femoral PPFs. Intriguingly, additional CT did not improve the evaluation of implant loosening. Nonetheless, CT scans are often performed if loosening assessment is unclear on regular radiographs. This fact can explain the bias CT results in comparison to regular radiography. However, software-supported CT diagnosis could help to adequately answer the question of loosened implants in PPF in the near future. Since the diagnosis of fracture and their morphology assessment is currently adequately performed using X-rays, CT shall not be considered as the gold standard.

Radiocarpal fusion and midcarpal resection interposition arthroplasty: long-term results in severely destroyed rheumatoid wrists.

BACKGROUND: The aim of this retrospective study is to evaluate distal resection interposition arthroplasty of the wrist as a tool to restore mobility as well as to restore stability in severely destroyed wrist joints. METHODS: Thirty-four wrists in 28 rheumatoid arthritis patients were included. The mean follow-up time was 9 years after surgical treatment with clinical and radiological examination. The results were accessed based on a modification of Clayton ́s scoring system as well as a functional questionnaire. RESULTS: 71% patients were satisfied with pain, function and activities of daily life. Better results were reported by patients with a young age, early surgical intervention, a shorter duration of the disease, and lesser involvement of other joints. CONCLUSIONS: The results for radiocarpal arthrodesis were comparable to those of synovectomy or arthrodesis of the wrist. The results after total wrist joint arthroplasty varies probably as the result of different patient groups, implant types and evolution of prosthetic designs, and are not comparable with the present study.

Creatine Supplementation Supports the Rehabilitation of Adolescent Fin Swimmers in Tendon Overuse Injury Cases.

Our purpose was to investigate the effect of creatine (Cr) supplementation on regeneration periods in tendon overuse injury rehabilitation of adolescent fin swimmers. The participants of this study were injured adolescent competitive fin swimmers (n = 18). The subjects were randomly assigned the creatine (CR) or placebo (PL) groups with a double-blind research design. The subjects were given Cr supplementation or received the placebo as part of the conservative treatment of the tendinopathy. We measured the segmental lean mass (SLM;kg), the ankle plantar flexion peak torque (PFT;N·m), the pain intensity (NRS;values), prior to immobilization, after immobilization (R2) and after the 2nd (R4) and 4th (R6) weeks of the rehabilitation period of the injured limb. The creatine kinase (CK; U/L) enzyme levels were measured before immobilization, and then every 24 hours for four days. There was a significant decrease in SLM (CR by 5.6% vs. PL by 8.9%; p < 0.03) after two weeks of immobilization in both groups (p < 0.001). After four weeks rehabilitation the SLM significantly increased in both groups (CR by 5.5% vs. PL by 3.8%; p < 0.01). The percent changes in PFT after supplementation in R4 (p < 0.001) and R6 (p < 0.03) were significantly different between groups. There was a significant percent increase measured in the CR group (R4 by 10.4%; p < 0.001; R6 by 16.8%; p < 0.001), whereas significant, but lower growth found in the PL group also took place (R4 by 7.1%; p < 0.001; R6 by 14.7%; p < 0.001) after four weeks of rehabilitation. Significantly faster decrease were found in NRS of CR versus PL group during treatment (p < 0.02). We detected significantly lower CK levels increase at the CR group compared to the PL group. The results of this study indicate that Cr supplementation combined with therapeutic strategy effectively supports the rehabilitation of tendon overuse injury of adolescent fin swimmers.

Erratum: Author's name correction.

[This corrects the article on p. 5 in vol. 6, PMID: 27299113.].

Isolated Acute Exertional Compartment Syndrome (AECS) of the Extensor Carpi Ulnaris.

INTRODUCTION: Only two cases of an isolated compartment syndrome of the extensor carpi ulnaris have been described previously [1,2]. In both cases, the onset was acute. In the first case, histological examination revealed no necrosis. The second case was regarded to be due to a previously unknown anatomic variation and no necrotic tissue was recognized upon gross examination. This case report describes a third case of an isolated acute exertional compartment syndrome (AECS) of the extensor carpi ulnaris muscle with focal areas of necrotic tissue. CASE REPORT: We report the third case of an isolated AECS of the extensor carpi ulnaris muscle. A 35 year-old left-handed man, a motor mechanic by profession, presented to the emergency department with excruciating pain at the ulnar side of the left dorsal forearm. The previous day, he had repetitively used a sliding hammer with his left arm. Since then he had experienced severe pain despite the use of over-the-counter non-steroidal anti-inflammatory drugs. Here, in contrast to the previously reported cases, the histological examination revealed focal areas of necrotic tissue. No anatomic variations were found during surgical decompression. Postoperatively, the patient had complete pain relief and return of function. CONCLUSION: This report again indicates that the extensor carpi ulnaris is especially prone to develop the AECS syndrome and raises the question whether involvement of the other extensor muscles may rather be secondary to the excessive swelling of the extensor carpi ulnaris and not to strenuous exercise. This should be taken into consideration when humans load their forearm repeatedly during heavy labor or sports. In addition, we are showing that even with histologically confirmed areas of partial muscle necrosis the patient can return to normal muscle function.

Is osteonecrosis of the lunate bone an underestimated feature of systemic sclerosis? A case series of nine patients and review of literature.

Osteonecrosis of the lunate bone, also known as Kienböck's disease, is a very rare disease of unknown cause. Until today, only six cases of osteonecrosis of the lunate bone in patients with systemic sclerosis (SSc) have been reported in the literature. It is unknown whether these few cases reflect only a coincidence of two rare diseases or whether osteonecrosis of the lunate bone is a potential currently underestimated disease-associated feature of SSc. In this study, we report the clinical course of nine SSc patients with magnetic resonance imaging proven osteonecrosis of the lunate bone and discuss associated disease characteristics and potential underlying pathophysiological mechanisms. Overall, our observations suggest that osteonecrosis of the lunate bone is a frequent and so far under-recognized manifestation of SSc which might be linked to SSc-related vasculopathy. It is important to distinguish osteonecrosis of the lunate bone from wrist arthritis in SSc patients because the clinical treatment is different. In general, the clinical progression of osteonecrosis of the lunate bone seems to be slow in SSc patients. As most of the patients have only minor complaints, watchful waiting in combination with analgesic therapy seems to be a feasible treatment approach in most patients whether an operative intervention might be necessary in rapid progressive cases.

Effects of dendritic core-shell glycoarchitectures on primary mesenchymal stem cells and osteoblasts obtained from different human donors.

The biological impact of novel nano-scaled drug delivery vehicles in highly topical therapies of bone diseases have to be investigated in vitro before starting in vivo trials. Highly desired features for these materials are a good cellular uptake, large transport capacity for drugs and a good bio-compatibility. Essentially the latter has to be addressed as first point on the agenda. We present a study on the biological interaction of maltose-modified poly(ethyleneimine) (PEI-Mal) on primary human mesenchymal stem cell, harvested from reaming debris (rdMSC) and osteoblasts obtained from four different male donors. PEI-Mal-nanoparticles with two different molecular weights of the PEI core (5000 g/mol for PEI-5k-Mal-B and 25,000 g/mol for PEI-25k-Mal-B) have been administered to both cell lines. As well dose as incubation-time dependent effects and interactions have been researched for concentrations between 1 µg/ml to 1 mg/ml and periods of 24 h up to 28 days. Studies conducted by different methods of microscopy as light microscopy, fluorescence microscopy, transmission-electron-microscopy and quantitative assays (LDH and DC-protein) indicate as well a good cellular uptake of the nanoparticles as a particle- and concentration-dependent impact on the cellular macro- and micro-structure of the rdMSC samples. In all experiments PEI-5k-Mal-B exhibits a superior biocompatibility compared to PEI-25k-Mal-B. At higher concentrations PEI-25k-Mal-B is toxic and induces a directly observable mitochondrial damage. The alkaline phosphatase assay (ALP), has been conducted to check on the possible influence of nanoparticles on the differentiation capabilities of rdMSC to osteoblasts. In addition the production of mineralized matrix has been shown by von-Kossa stained samples. No influence of the nanoparticles on the ALP per cell has been detected. Additionally, for all experiments, results are strongly influenced by a large donor-to-donor variability of the four different rdMSC samples. To summarize, while featuring a good cellular uptake, PEI-5k-Mal-B induces only minimal adverse effects and features clearly superior biocompatibility compared to the larger PEI-25k-Mal-B.

Histological Comparison of New Biodegradable Magnesium-Based Implants for Maxillofacial Applications.

BACKGROUND: A variety of materials have been used for bone augmentation, distraction osteotomy, and in post-cancer patients following tumor removal. However, a temporary metal implant that would resorb after successful treatment is a new concept. Magnesium was suggested as a suitable material for these purposes because it is biocompatible, has better mechanical properties than titanium, and stimulates new bone formation. This study evaluates histological appearance of magnesium-based implants and the surrounding bone. MATERIALS AND METHODS: Three magnesium-based biomaterials were tested in a rabbit bone defect model: magnesium-hydroxyapatite (Mg-HA), W4 (96 % magnesium, 4 % yttrium), and pure magnesium (pure Mg). Animals were sacrificed after 6 and 12 weeks and the samples were analyzed histologically and histomorphometrically. RESULTS: Mg-HA had the highest mean amount of tartrate-resistant acid phosphatase (TRAP) positive cells at the implantation site of all groups. It had shown the fastest degradation rate already at 6 weeks but the least amount of new bone formation. New bone was seen forming in direct contact with pure Mg and W4. The mean gas volume was highest in W4 compared to pure Mg and Mg-HA but this difference was not statistically significant. W4 had the lowest mean number of TRAP-positive cells of all materials. CONCLUSION: Pure Mg and W4 were shown to be the most promising materials in this study in respect to the bone response to the implant material. They could be used for screws and plates in bone augmentation procedures.

Regulation of acetylcholine receptors during differentiation of bone mesenchymal stem cells harvested from human reaming debris.

Acetylcholine (ACh) is an important signaling molecule in non-neuronal systems where it is involved in regulation of viability, proliferation, differentiation and migration of mesenchymal stem cells (MSC) that are capable to differentiate into osteoblasts, chondrocytes and adipocytes. Patients with the systemic disease osteoporosis show altered MSC properties, reduced bone formation and mineral density followed by increased bone fragility and high fracture incidence. Here we asked whether nicotinic and muscarinic acetylcholine receptors (AChR) are expressed in osteoblasts, adipocytes and chondrocytes differentiated from bone MSC extracted from human reaming debris (RDMSC) that was harvested during surgery of long bone diaphyseal fractures. Using RT-PCR, AChR were detected in RDMSC, osteoblasts, chondrocytes and adipocytes of male and female bone-healthy and of female osteoporotic donors. An up-regulation in multiplicity and occurrence of AChR subtypes was found in female compared to male donors and in osteoblast of male donors compared to adipocytes. Real-time RT-PCR analysis resulted in a significant increase in relative expression of nAChR α9 in chondrocytes compared to adipocytes of healthy female donors. The nAChR subunit α10 was significantly up-regulated in osteoblasts of healthy compared to osteoporotic donors as well as the mAChR M5 that is additionally decreased in osteoporotic osteoblasts compared to MSC and chondrocytes of osteoporotic donors. In summary, the gene expression of AChR during differentiation of RDMSC and its regulation in cells of osteoporotic donors lead to the assumption that AChR signaling is involved in bone formation and might be utilized to stimulate bone remodeling processes.

[Primary results using the mini TightRope for revision surgery for painful proximalisation of the first metacarpal after trapezectomy for CMC-1-osteoarthritis]. / Erfahrungen mit dem Mini TightRope bei schmerzhafter Proximalisierung des 1. Mittelhandstrahls nach Trapezektomie bei Rhizarthrose.

AIM: The aim of the current study was to review the significance of the TightRope to suspend the first metacarpal in the case of a revision for patients with painful proximalisation after trapezectomy. PATIENTS AND METHOD: After an average of 25.5 months (13-60) from initial operative treatment for rhizarthrosis, revision surgery was performed on 6 female patients with a mean age of 56 years, using a Mini TightRope. Before and after revision-surgery the pain level was measured, using the visual analogue scale (1-10) as was the level of strength in the fingertips. The overall result was documented according to the evaluation scale according to Buck-Gramcko. Directly after surgery as well as at the last follow-up exam, the degree of proximalisation of the first metacarpal was radiologically measured. The follow-up period was 13.7 months on average (4-31 months). RESULTS: After revision surgery a decrease in pain level was detected, but no patient was completely pain-free. According to the visual analogue scale the pain level after surgery compared to preoperatively was: at rest at an average of 2.5 (1-4), preoperatively 3.3 (2-4); with mild load 3.5 (2-5), preoperatively 4.8 (4-6); and with high load 4.8 (3-7), preoperatively 7 (6-8). The level of strength in the fingertips was postoperatively measured at below 60% in 2 patients (preoperatively 5 patients), once between 60 and 79% (preoperatively 1 patient) and 3 times between 80 and 99%. With an average preoperative score of 11.7 (6-16) points according to Buck-Gramcko, an increase of 20.3 points could be achieved by performing the revision operation. This resulted in a score of 32 (14-44) out of 56 points. The measured distance between the distal scaphoid pole and the centre of the base of the first metacarpal was postoperatively at an average of 8.3 mm (5.6-11.4 mm). The final follow-up shows an average distance of 3.3 mm (2.8-4.3 mm). This is consistent with an average proximalisation of 5 mm. The Mini TightRope had to be removed three times. An additional operation had to be performed twice. CONCLUSION: The use of the Mini TightRope for a suspension of the first metacarpal, in cases of a painful proximalisation after trapezectomy is a procedure that can cause an improvement for a certain percentage of patients. But a further proximalisation cannot be prevented by the use of the Mini TightRope.

The biocompatibility of degradable magnesium interference screws: an experimental study with sheep.

Screws for ligament reconstruction are nowadays mostly made of poly-L-lactide (PLLA). However, magnesium-based biomaterials are gathering increased interest in this research field because of their good mechanical property and osteoanabolic influence on bone metabolism. The aim of this pilot study was to evaluate the biocompatibility of an interference screw for ligament reconstruction made of magnesium alloy W4 by diecasting and milling and using different PEO-coatings with calcium phosphates. PLLA and titanium screws were used as control samples. The screws were implanted in the femur condyle of the hind leg of a merino sheep. The observation period was six and twelve weeks and one year. Histomorphometric, immunohistochemical, immunofluorescence, and molecular biological evaluation were conducted. Further TEM analysis was done. In all magnesium screws a clinically relevant gas formation in the vicinity of the biomaterial was observed. Except for the PLLA and titanium control samples, no screw was fully integrated in the surrounding bone tissue. Regarding the fabrication process, milling seems to produce less gas liberation and has a better influence on bone metabolism than diecasting. Coating by PEO with calcium phosphates could not reduce the initial gas liberation but rather reduced the bone metabolism in the vicinity of the biomaterial.

In vitro assessment of nanosilver-functionalized PMMA bone cement on primary human mesenchymal stem cells and osteoblasts.

Peri-prosthetic infections caused by multidrug resistant bacteria have become a serious problem in surgery and orthopedics. The aim is to introduce biomaterials that avoid implant-related infections caused by multiresistant bacteria. The efficacy of silver nanoparticles (AgNP) against a broad spectrum of bacteria and against multiresistant pathogens has been repeatedly described. In the present study polymethylmethacrylate (PMMA) bone cement functionalized with AgNP and/or gentamicin were tested regarding their biocompatibility with bone forming cells. Therefore, influences on viability, cell number and differentiation of primary human mesenchymal stem cells (MSCs) and MSCs cultured in osteogenic differentiation media (MSC-OM) caused by the implant materials were studied. Furthermore, the growth behavior and the morphology of the cells on the testing material were observed. Finally, we examined the induction of cell stress, regarding antioxidative defense and endoplasmatic reticulum stress. We demonstrated similar cytocompatibility of PMMA loaded with AgNP compared to plain PMMA or PMMA loaded with gentamicin. There was no decrease in cell number, viability and osteogenic differentiation and no induction of cell stress for all three PMMA variants after 21 days. Addition of gentamicin to AgNP-loaded PMMA led to a slight decrease in osteogenic differentiation. Also an increase in cell stress was detectable for PMMA loaded with gentamicin and AgNP. In conclusion, supplementation of PMMA bone cement with gentamicin, AgNP, and both results in bone implants with an antibacterial potency and suitable cytocompatibility in MSCs and MSC-OM.

Plasmatic isoforms of cytokeratin 18 and RAGE after severe trauma: a longitudinal cohort study.

BACKGROUND: Life-threatening traumatic injuries lead to a complex inflammation-driven pathophysiology. Receptor of advanced glycation end product (RAGE) is a multiligand receptor of several endogenous alarmins, while cytokeratin 18 is a structural component of the filament of epithelial cells. Both proteins can be frequently found in plasma of patients with different diseases, whereby they have distinct underlying mechanism of formation. In this prospective observational study, we wanted to shed light on the kinetic of plasmatic RAGE and cytokeratin 18 isoforms after severe trauma, thereby also addressing the association of these markers with inflammation and their potential use as biomarkers. METHODS: Plasma samples of 77 patients with severe multiple trauma as defined by an Injury Severity Score (ISS) 16 or greater were obtained from a local repository and levels of soluble RAGE, endogenous secretory RAGE, cytokeratin 18, cleaved cytokeratin 18, and interleukin 6 by enzyme-linked immunosorbent assay. Demographic and routine parameters of the cohort were extracted from an electronic patient data management system. RESULTS: Both RAGE isoforms were transiently increased in plasma within 24 hours after trauma, while cytokeratin 18 levels were unchanged. Moreover, soluble RAGE concentrations in patients with thoracic injuries were higher compared with patients without injury, and both isoforms of RAGE discriminated between patients with most severe adult respiratory distress syndrome and patients with milder forms. In addition, cleaved and total cytokeratin 18 levels differ between patients with hepatic dysfunction and normal function, without possessing discriminatory power. RAGE and cytokeratin 18 isoforms correlated significantly but to a low extent with interleukin 6, while the isoforms of both parameters correlated to a high extent with one another. CONCLUSION: The release of RAGE (but not cytokeratin 18) isoforms occurs early and transiently after trauma and is associated with the extent of injury and inflammatory response. RAGE and cytokeratin 18 isoforms have the potential to act as diagnostic or prognostic biomarkers of lung and hepatic dysfunction. LEVEL OF EVIDENCE: Epidemiologic/prognostic study, level IV.