Recommendations for return to sports after total hip arthroplasty are becoming less restrictive as implants improve.

INTRODUCTION: Total hip arthroplasty (THA) surgeries are expected to exponentially increase in the upcoming years, likely because of the overall broader indication of THAs. With these developments, an increasing number of younger (< 50 years) and active patients will receive surgical interventions, and expectations for an active lifestyle will accordingly increase. In addition, surgeons now have a growing array of techniques and implant materials to choose from. Despite these developments, evidence to provide the best standard-of-care to patients with high expectations for return to sports (RTS) is scarce and urgently needed. What recommendations do arthroplasty surgeons currently make to patients with high return to sports expectations, what factors may influence their recommendations and what surgical techniques and implant specifications are considered favorable in the treatment of patients with a more active lifestyle? This study was conducted to analyze the current recommendations, patient assessment, and patient counseling after THA to identify trends and relevant factors for surgical decision-making in patients with high-RTS expectations. MATERIAL AND METHODS: We designed a questionnaire comprising five general items and 19 specific items that included 46 sub-items for hip arthroplasty and conducted a survey among 300 German surgeons specialized in arthroplasty at the German Arthroplasty Society (AE) to assess expert opinions, recommendations, surgical decision-making, and patient counseling for patients with high expectations for RTS after THA. RESULTS: The majority of surgeons (81.9%) were in favor of RTS after THA. Risks associated with sports after THA were considered minimal (1%), with periprosthetic fractures ranking highest, followed by hip dislocation and polyethylene wear. Some surgical decision-making was influenced by high-RTS expectations in regard to implant fixation, stem type, femoral head diameter, and bearing-surface tribology. We observed an increasingly liberal counseling of patients for high-impact sports. CONCLUSION: With the improvement of implants and surgical techniques, surgeons are more willing to encourage patients to adopt a more active lifestyle. However, the true long-term limitations need further investigation in future studies. LEVEL OF EVIDENCE: 5 Expert opinions.

[Diagnosis of periprosthetic joint infection : Development of an evidence-based algorithm by the work group of implant-associated infection of the AE-(German Society for Arthroplasty)]. / Diagnostik der periprothetischen Infektion : Entwicklung eines evidenzbasierten Algorithmus der Arbeitsgruppe implantatassoziierte Infektion der Arbeitsgemeinschaft Endoprothetik.

BACKGROUND: Prosthetic joint infections (PPI) will challenge orthopaedic surgeons and the health care system in the coming years. Evidence-based and reliable preoperative diagnostics are necessary for success in the field of revision arthroplasty. Especially the preoperative detection of PPI is important with respect to the treatment strategy. AIM: The aim of this study was to develop a detailed and structured standard operating procedure (SOP) to detect PPI preoperatively. METHODS: A systematic literature research was performed and relevant articles identified. After extracting the data, statistical calculations of sensitivity, specificity, positive/negative predictive value and positive/negative likelihood ratio were performed. The results were discussed and evaluated in four meetings analogously to standard Delphi rounds by the workgroup of implant-associated infections of the German AE (Arbeitsgemeinschaft Endoprothetik). An algorithm for the diagnostic approach according to ISO 5807 was made. RESULTS: The standardized algorithm combines a sequence of evidence-based procedures with detailed and structured main and additional criteria to every critical step in the diagnostic approach. CONCLUSION: The detection of PPI is of tremendous importance prior to revision arthroplasty and determines its success or failure. The diagnosis "prosthetic joint infection" requires a substantial change with respect to treatment concepts. The algorithm summarizes current literature and specialized expert opinions in a modern standardized format for a transparent diagnostic approach.

[Surgery of sepsis in orthopedics and trauma - A highlight : Current survey by the section for bone and soft tissue infections of the German Society for Orthopedics and Trauma]. / Septische Chirurgie in OuU ­ ein Schlaglicht : Aktuelle Umfrage der DGOU-Sektion Knochen- und Weichteilinfektionen.

Surgery of sepsis in trauma surgery and orthopedics is attracting increasingly more attention due to the rising presence of multidrug-resistant pathogens and the increasing number of operative interventions. Despite extensive experience over decades neither the symptoms nor the treatment strategies have been evaluated and it has become obvious that a scientific investigation of this complex topic is necessary for optimization of patient care under economically sound conditions. The aim of this article is to give a snapshot from German healthcare institutions for trauma surgery and orthopedics to answer some questions on this topic from the section for bone and soft tissue infections (SeKuWi) of the German Society for Orthopedics and Trauma (DGOU) in cooperation with the German Society for Hospital Hygiene (DGKH).

Pulmonary metastasectomy for metastasized hepatocellular carcinoma after liver resection and liver transplantation: a single center experience.

BACKGROUND: The role of surgery in the treatment of metastasized hepatocellular carcinoma (HCC) remains uncertain. We here report our single centre experience with pulmonary metastasectomy (PM) for metachronous HCC metastases to the lung following curative liver resection (LR) and liver transplantation (LT), respectively. METHODS: Of 270 patients with HCC being treated by LR or LT at the University Hospital of Leipzig between January 1996 and July 2014, PM was performed in the follow up of 10 patients because of metachronous pulmonary HCC metastases. We retrospectively analyzed demographic and clinicopathological factors as well as the outcome after primary and secondary tumor treatment in these patients. RESULTS: Following LR/LT and metastasectomy, respectively, mean overall survival was 4.58 ± 0.84 years and 2.4 ±â€Š0.69 years. Postoperative morbidity after primary and secondary tumor treatment was 30 % and 20 %, respectively. Perioperative 30-day mortality was 0 %. Univariate analysis suggest tumor grading (p < 0.05), and a disease free-intervall > 1 year (p = 0.02) as significant prognostic parameters for survival in our collective. CONCLUSION: PM can be performed safely with a reasonable morbidity even in immunosuppressed patients after LT. Further studies are needed to evaluate whether PM can increase long-term survival in selected patients with resectable metastases and represents an alternative or additive treatment modality to the protein kinase inhibitor sorafenib.

Revised histopathological consensus classification of joint implant related pathology.

This extended classification of joint implant related pathology is a practical histopathologic classification based on defined morphological criteria covering the complete spectrum of pathohistologic changes in periprosthetic tissues. These changes may occur as a consequence of endoprosthetic replacement of large joints and may lead to a reduction in the prosthesis survival rate. We describe the established consensus classification of the periprosthetic membrane, in which aseptic and septic prosthetic loosening can be subdivided into four histological types, as well as histopathological criteria for additional significant pathologies including endoprosthetic-associated arthrofibrosis, particle-induced immunological, inflammatory and toxic mechanisms (adverse reactions), and bone tissue pathologies. These characteristic tissue alterations and their relationships are summarized in the extended classification. Since particle heterogeneity in periprosthetic tissue is high and particle identification is a necessary part of diagnosis, the identification of different types of particles is described in the histopathological particle algorithm. The morphological qualities of prosthetic material particles and the demarcation between abrasion and non-abrasion endogenous particles are also summarized. This feasible classification which is based on low cost standard tissue processing and examination and on well-defined diagnostic criteria is a solid platform for the histological diagnosis of implant associated pathologies providing a stable and reproducible tool for the surgical pathologist. Since this classification is suitable for standardized histopathological diagnostics, it might also provide a useful data set for joint arthroplasty registers, particularly for registers based on so-called routine data.

[Revised consensus classification. Histopathological classification of diseases associated with joint endoprostheses]. / Erweiterte Konsensusklassifikation. Histopathologische Klassifikation von Gelenkendoprothesen-assoziierten Erkrankungen.

The revised classification of the periprosthetic membrane (synovial-like interface membrane SLIM) encompasses all pathological alterations which can occur as a result of endoprosthetic replacement of major joints and lead to a reduction in durability of prostheses. This also includes the established consensus classification of SLIM by which aseptic and septic prosthetic loosening can be subdivided into four histological types and histopathological criteria for additional pathologies: endoprosthesis-associated arthrofibrosis, immunological/allergic alterations and osseous pathologies. This revision represents the foundation for the histopathological diagnostics of the total spectrum of diseases associated with joint prostheses, is a suitable basis for a standardized diagnostic procedure and etiological clarification of endoprosthesis failure and also as a data standard for endprosthesis registers, in particular for registers based on routine data (e.g. German endoprosthesis register).

[Synovialitis of the arthrofibrotic type: criteria of a new synovialitis type for the diagnosis of arthrofibrosis]. / Synovialitis vom arthrofibrotischen Typ: Kriterien eines neuen Synovialitis-Typus für die Diagnose der Arthrofibrose.

After rheumatologic conservative medical therapy has been exhausted in degenerative and inflammatory joint diseases, arthroplastic operations are an important option to restore quality of life. Endoprosthesis-associated arthrofibrosis is a severe fibrosing disease of the synovial membrane after endoprosthetic operations. Neither the morphological substrate nor histopathological criteria have been described. The aim was to describe the histopathological substrate of arthrofibrosis and to define histological and immunohistochemical criteria of arthrofibrosis on the basis of tissue samples derived from revision. In histopathological analyses arthrofibrosis revealed a synovialitis with varying fibrosis, without detectable ossification and without minimal wear particle reaction (so-called synovialitis of arthrofibrotic type, SAT). A 3-stage grading was determined based on the cellular density of the fibrous tissue (fibroblast cellularity). In 191 cases with SAT, grade 1 was found in 24.1 % (n = 46), grade 2 was found in 51.8 % (n = 99) and grade 3 was found in 24.1 % (n = 46). The control group consisted of 29 cases with synovialitis of indifferent type (type IV membrane). If SAT grades 2 and 3 are summed together, i.e. the distance between the fibroblasts was less than two cell lengths, the difference of the fibroblast cellularity compared with the type IV membrane was significant (p < 0.001). Above SAT grade 2 the diagnosis of arthrofibrosis could be made with a sensitivity 0.7592 and specificity 0.8276. The SM-alpha-actin cytoplasmic positivity of fibroblasts indicates a myofibroblast phenotype and the ß-catenin positivity suggests a resemblance to fibromatosis or a keloid-like process. In the quantitative evaluation of the ß-catenin positive fibroblasts, there was a significant difference (p < 0.001) between type IV membrane and SAT. A threshold value of 20 beta-catenin positive cells per microscopic high power field (HPF) was determined, which represents in conjunction with the clinical information a new histopathological diagnosis component (sensitivity 0.720, specificity 0.867).

[Joint endoprosthesis pathology. Histopathological diagnostics and classification]. / Gelenkendoprothesenpathologie. Histopathologische Diagnostik und Klassifikation.

Prosthesis durability has steadily increased with high 10-year rates of 88-95%. However, four pathogenetic groups of diseases can decrease prosthesis durability: (1) periprosthetic wear particle disease (aseptic loosening) (2) bacterial infection (septic loosening) (3) periprosthetic ossification, and (4) arthrofibrosis. The histopathological "extended consensus classification of periprosthetic membranes" includes four types of membranes, arthrofibrosis, and osseous diseases of endoprosthetics: The four types of neosynovia are: wear particle-induced type (type I), mean prosthesis durability (MPD) in years 12.0; infectious type (type II), MPD 2.5; combined type (type III) MPD 4.2; and indeterminate type (type IV), MPD 5.5. Arthrofibrosis can be determined in three grades: grade 1 needs clinical information to be differentiated from a type IV membrane, and grades 2 & 3 can be diagnosed histopathologically. Periprosthetic ossification, osteopenia-induced fractures, and aseptic osteonecrosis can be histopathologically diagnosed safely with clinical information. The extended consensus classification of periprosthetic membranes may be a diagnostic groundwork for a future national endoprosthesis register.

[Infection management of megaimplants]. / Infektionsmanagement bei Megaimplantaten.

More and more megaprostheses are being implanted - not just injuries or primary and secondary bone tumors, but also the increase in extended bone defects in revision arthroplasty call for the more frequent use of megaimplants. Underlying disease, medication, age, and frequency of surgical procedures give rise to infections which occur in more than 10% of the patients receiving megaprostheses. Size, surface, and design of the implants themselves increase the infection rate.Every year we treat more than 45 patients with periprosthetic infections of megaimplants and large revision prostheses, many of them infected with multi-resistant germs. MRSE and MRSA have been shown to increase the rate of relapses (19%). The treatment strategy continues to consist of multiple steps, and temporary stabilization is achieved either externally with external fixation devices or orthoses or internally with spacers (PMMA, interim implants). To avoid relapsing infections surgeons must rely on anti-infective surface coatings (silver), local drug carriers (collagen, PMMA), and especially soft tissue coverage with local muscle flaps and radical treatment of the bone infection. Amputations, however, cannot be avoided completely; 5% of our patients had to undergo amputations above the knee after infections of megaimplants.Surgery will be required more frequently to treat infections of megaprostheses and increase the medical, nursing, logistic, technological, and financial burden on the patients, surgeons, clinics, and insurance companies.

Erythrocytes and proinflammatory mediators in wound drainage.

BACKGROUND AND OBJECTIVES: Retransfusion of shed blood collected after operation has become popular, but recent reports of side effects led to a search for possible causes. MATERIALS AND METHODS: In a randomized study of 28 patients undergoing total hip arthroplasty, shed blood was collected in Solcotrans, Orth-Evac, and ordinary Redon drainage. Osmotic fragility was measured and electron-microscopic pictures of erythrocytes from selective samples were taken. Serotonin, prostaglandin E2 (PGE2), and histamine were measured with enzyme-linked immunosorbent assays. RESULTS: Higher osmotic fragility of erythrocytes collected with Solcotrans appeared to be due to ACD which was used only with that system. Serotonin concentrations did not differ significantly. However, there was a great increase in histamine (Solcotrans 477.7, Orth-Evac 344.0, Redon drainage 453.1 nmol/ml) and PGE2 (Solcotrans 1,908.3, Orth-Evac 1,225.0, Redon drainage 2,666.7 microgram/ml) in shed blood compared with venous blood (histamine 9.5 nmol/l, PGE2 4.2 microgram/ml). CONCLUSION: Unwashed wound drainage blood collected after operation contains levels of proinflammatory mediators that can account for the reported side effects.

[Interspecies comparison of healing standardazed bone defects with and without autogenous bone transplantation]. / Interspeziesvergleich zur Heilung standardisierter Knochendefekte mit und ohne autogene Knochentransplantation.

This study tries to establish a basis for comparison of animal studies regarding bone defect healing. Pigs, sheep and rabbits were operated on according to a standardized scheme where each received bilateral defects of the femoral condylus. One of the defects was filled with cancellous autograft, the other remained empty. Bone defect healing was followed with several different methods of investigation, the results were put into perspective with the help of a standardized score-scheme.

[Rapid prototyping. Construction of a model in the preoperative planning of reconstructive pelvic interventions]. / Rapid Prototyping. Modellherstellung zur präoperativen Planung von rekonstruktiven Beckeneingriffen.

X-ray or CT images allows only a limited three-dimensional orientation in presurgical planning. Especially for the planning of internal hemipelvectomies with custom-made endoprosthesis and for peri-acetabular osteotomies a high-grade orientation is necessary. This orientation is improved by a 3D CT-controlled manufactured 1:1 model of the pelvis. This enables and exact classification of defect and deformity, planning of resection planes, design of the suitable custom-made implant and simulation of the operation technique as preoperative quality control.

[Tribological properties of carbon fiber-reinforced plastic. Experimental and clinical results]. / Tribologische Eigenschaften von kohlenstoffaserverstärktem Kunststoff (CFK). Experimentelle und klinische Ergebnisse.

Wear of the articulating components (especially PE-UHMW) of total hip endoprostheses is the most important technical factor limiting the functional lifetime. To minimize wear debris, ceramic heads, according to ISO 6474 (Al2O3), have been used, from 1969 paired with Al2O3 and since 1975 paired with PE-UHMW. Al2O3 balls articulating with cups made from CFRP have been in clinical use since 1988. Laboratory experiments and in-vivo testing showed minimized wear debris and mild biological response to wear products using CFRP (carbon fiber reinforced plastic) instead of PE-UHMW as the cup material. The articulating surfaces of retrieved ceramic heads (Al2O3-Biolox) and cementless CFRP cups (carbon fiber reinforced plastic, Caproman) were compared using sphericity measurement techniques, scanning electron microscopy (SEM) and roughness measurements (including advanced roughness parameters Rvk or Rpk according to ISO 4287). Altogether, the first results of the clinical study showed that the combination Al2O3-ball/CFRP-cup came up to the expected lower wear rates compared with the conventional combinations. The wear rates are comparable with the combination Al2O3/Al2O3 without the material-related problems of ceramic components in all ceramic combinations.

Extracorporeal irradiation and incorporation of bone grafts. Autogeneic cortical grafts studied in rats.

The incorporation of resected, extracorporeally irradiated (1, 5, 25 and 50 kGy) and orthotopically reimplanted autogeneic cortical bone was investigated in 116 adult Wistar rats. 7 mm-long diaphyseal segments of the tibia were resected, irradiated and reimplanted using K-wire osteosynthesis. Autogeneic fresh grafts served as controls. Graft healing was evaluated by radiography and histomorphometric study at 3, 6, 9, and 12 weeks. At 3 weeks, two thirds of the 50 kGy irradiated grafts were fractured and therefore the series with this dose was interrupted because of mechanical graft insufficiency. After 3 and 6 weeks there were no statistically significant differences among the control group and 1 or 5 kGy irradiated grafts. The healing of 25 kGy irradiated grafts was delayed from the sixth week onwards and continued until the end of the experiment at 12 weeks (50% reduction of incorporation). The incorporation of 1 and 5 kGy irradiated grafts showed a 16% (1 kGy) to 24% (5 kGy) delay at 12 weeks, compared to autogeneic fresh grafts. 1 and 5 kGy irradiated autogeneic bone grafts retain most of their biological potential. Resection, extracorporeal irradiation and reimplantation of bone tumors may therefore be a possible alternative to allografting.

[A method for determining the biomechanical properties of trabecular and spongiosa bone tissue]. / Eine Methode zur Bestimmung biomechanischer Eigenschaften von Trabekeln und Knochengewebe der Spongiosa.

With the aim of determining the biomechanical properties of cancellous bone, a method was developed that permits the investigation of the effects of tensile and compressive forces on cancellous bone trabeculae while eliminating the problem of porosity. Individual, rod-like trabeculae were removed from cancellous bone with the aid of special instruments. Each end of a trabeculae was embedded in a cylinder of polymethylmethacrylate. To keep bending moments to a minimum while testing, the trabeculae was aligned along the longitudinal axis of the cylinders with the aid of positioning instruments. With a test apparatus, the deformation behaviour and maximum strength of the trabeculae under tension and compression can be determined under both dry and moist conditions. With account being taken of shape and dimensions of the trabeculae, the material properties of the cancellous bone tissue can be computed. In comparison with the small number of methods so far used for investigating trabeculae, a number of advantages were found: 1. Tensile and compression testing in a single specimen, 2. testing under reliably moist conditions, 3. non-destructive testing enabling further investigations on the specimen.

[Mechanical stability of hip joint endoprosthesis shafts of carbon fiber composite materials]. / Mechanische Sicherheit von Hüftgelenkendoprothesenschäften aus Kohlenstoffaserverbundwerkstoff.

The use of composite materials in orthopaedic surgery permits the design of implants with varying degrees of stiffness. A system of carbon fibre reinforced epoxy hip stems was investigated and compared to the mechanical safety of metal ones. Special attention has been paid to the fact that torsional moments are the common failure mechanism of composite materials. In total 74 hip stems (three different sizes) have been tested under static and dynamic loading conditions according to ISO 7206. A group of 27 implants was pre-conditioned for 75 days in 80 degrees C Ringer's solution to discover potential degradation effects of absorbed fluids. The carbon fibre hip stems proved to reach run-out loads higher than conventional metal ones. Moisture absorption didn't influence the mechanical properties within the range of the experimental accuracy. The calculated fatigue stress of 750 MPa permits further optimization of stiffness parameters without the risk of implant fracture.

[Biomechanics of healing of cortical autotransplants after intramedullary nailing and device removal]. / Biomechanik der Heilung kortikaler Autotransplantate nach Marknagelung und Materialentfernung.

The aim of the study was to investigate the biomechanical properties of segmental cortical autografts subjected to extracorporeal treatment. For this purpose, 12 beagle dogs were submitted to tibial osteotomy, when 25 mm-long diaphyseal segments of bone were removed and treated outside the body by autoclaving or gamma radiation (Co, 5 kGy). Subsequently, osteosynthesis involving the use of medullary nailing was performed. After 36 weeks, the dogs were killed painlessly and, after removing the nails, the tibias were tested for the biomechanical properties. In comparison with the contralateral tibia, a mean stiffness of 47% and 32% was measured for tibia treated by irradiation and autoclaving, respectively, while bending showed an increase of up to 590%. These results show the need to allow plenty of time for healing in the case of weightbearing transplants. When bealing is undisturbed, no biomechanical differences are found between proximal and distal osteotomies, although in the X-ray image the osteotomy gap (fracture line) remains visible, and scintigraphic activity persists for a longer period. This means that the radiological aspect of the former does not necessarily reflect actual biomechanical strength.

[Preservation and sterilization of cortical bone--biomechanical studies of the rat]. / Konservierung und Sterilisation von Kortikalis--biomechanische Untersuchungen an der Ratte.

The biomechanical properties of cryopreserved, autoclaved, irradiated and chemically treated cortical bone harvested from rat tibiae were evaluated in three-point bending. Biomechanical parameters (maximum bending load, deflection, failure energy and stiffness) are not altered by cryopreservation (-70 degrees C, 28 days) or irradiation with doses of 1 kGy or 5 kGy. The maximum bending load of autoclaved (134 degrees C, 3 min) or irradiated (25 kGy) cortical bone is reduced to 82% and 74% compared that of controls tested immediately after death (100% = 74.4 +/- 6.6 N). Extension of the autoclaving time from 3 to 5 min or irradiation with 50 kGy diminishes the bending load (28% after autoclaving, 48% after irradiation), deflection and failure energy. Stiffness is altered by autoclaving only. If a sterilization process is combined with deep freezing, better biomechanical values are obtained by sterilizing the bone before deep freezing than vice versa. The bending loads for autoclaving and irradiation before deep freezing are 68.8 +/- 9.4 N and 50.8 +/- 7.9 N, as against 51.7 +/- 2.7 N and 43.1 +/- 3.9 N for autoclaving and irradiation of previously cryopreserved bone. Whereas treating bone with tetrahydrofurane does not alter its biomechanical behavior, 80% ethanol leads to a reduction of structural properties.

[Experimental studies of the biomechanical properties of hollow nails and solid nails for interlocking intramedullary nailing in the dog]. / Experimentelle Untersuchungen über die biomechanischen Eigenschaften von Hohlnägeln und Vollnägeln zur verriegelbaren Marknagelung am Hund.

Since locked intramedullary nailing of the tibia in dogs was followed by material failure of the conventional slotted hollow nails within days, special solid nails were developed and tested with respect to their mechanical properties. There was a clear advantage of the solid nails over the hollow nails in terms of bending resistance and yield force. In animal experiments--even in long-term experiments over nine months--no case of material failure occurred with the solid nails. The high torsional and bending resistance of the solid nails suggests the use of a mechanical device which, as our experience shows, permits reliable interlocking without the need for an image intensifier, that is to say, without radiation exposure.