Good to excellent long-term survival of a single-design condylar constrained knee arthroplasty for primary and revision surgery.

PURPOSE: The purpose of the study was to determine the long-term survivorship, functional outcomes of a single-design condylar constrained (CCK) TKA in primary and revision cases as well as to assess specific risk factors for failure. It was hypothesized that primary CCK TKA had a better survival than revision knees. METHODS: One hundred and forty three patients who underwent revision TKA (n = 119) or complex primary TKA (n = 24) using a single-design condylar constrained knee system (Genesis CCK, Smith & Nephew) performed at a single institution between 1999 and 2008 were retrospectively included. The median follow-up amounted to 11.8 years (IQR 10.3-14.4). Implant survivorship was analyzed using Kaplan-Meier survival estimates and multivariate Cox regression analysis to identify risk factors for failure. Function was determined using the Oxford Knee Score (OKS). RESULTS: The implant survival was 86.4% after five, 85.5% after ten and 79.8% at 15 years. A reduced implant survivorship was found in males (HR 5.16, p = 0.001), smokers (HR 6.53, p = 0.004) and in obese patients (HR 2.26, p = 0.095). Patients who underwent primary TKA had a higher revision-free implant survivorship compared to revision TKA at 15 years (100% vs. 76%, p = 0.036). The main cause for re-revision was infection in 10% of all revision TKA performed with the CCK design included, while no case was revised for instability. The median OKS was 39 (IQR 35-44) in 102 patients available for long-term functional outcome. CONCLUSION: CCK implants are associated with excellent long-term survival when used in primary TKA; however, survival was worse when used during revision TKA. Males, smokers, obese patients and are at higher risk for revision. While instability and aseptic loosening were rare, infection remains a major concern. LEVEL OF EVIDENCE: Level IV, retrospective observational study.

siRNA mediated knockdown of tissue factor expression in pigs for xenotransplantation.

Acute vascular rejection (AVR), in particular microvascular thrombosis, is an important barrier to successful pig-to-primate xenotransplantation. Here, we report the generation of pigs with decreased tissue factor (TF) levels induced by small interfering (si)RNA-mediated gene silencing. Porcine fibroblasts were transfected with TF-targeting small hairpin (sh)RNA and used for somatic cell nuclear transfer. Offspring were analyzed for siRNA, TF mRNA and TF protein level. Functionality of TF downregulation was investigated by a whole blood clotting test and a flow chamber assay. TF siRNA was expressed in all twelve liveborn piglets. TF mRNA expression was reduced by 94.1 ± 4.7% in TF knockdown (TFkd) fibroblasts compared to wild-type (WT). TF protein expression in PAEC stimulated with 50 ng/mL TNF-α was significantly lower in TFkd pigs (mean fluorescence intensity TFkd: 7136 ± 136 vs. WT: 13 038 ± 1672). TF downregulation significantly increased clotting time (TFkd: 73.3 ± 8.8 min, WT: 45.8 ± 7.7 min, p < 0.0001) and significantly decreased thrombus formation compared to WT (mean thrombus coverage per viewing field in %; WT: 23.5 ± 13.0, TFkd: 2.6 ± 3.7, p < 0.0001). Our data show that a functional knockdown of TF is compatible with normal development and survival of pigs. TF knockdown could be a valuable component in the generation of multi-transgenic pigs for xenotransplantation.

[Bone defect reconstruction in bone sarcoma surgery: tumour endoprosthesis versus biological reconstruction]. / Rekonstruktion knöcherner Defekte in der Knochensarkomchirurgie: Tumorendoprothese vs. biologische Rekonstruktion.

BACKGROUND: Primary bone sarcomas typically arise in the long bones and the pelvis of children and adolescence but may also occur in adults. Meta/diaphysial tumour involvement resulting in the necessity of a joint replacement is more common than diaphysial tumour sites. AIM: In the treatment of these tumours, both endoprosthetic replacement and biological reconstruction techniques are used. Each technique has method-specific advantages and disadvantages. RESULTS: To choose the appropriate surgical method, a multitude of influencing parameters need to be considered. The age at treatment (soft tissue situation/estimated growth/biological potential of the bone), therapeutic concept (palliative vs. curative), the tumour site (upper/lower extremity), tumour expansion (diaphysis/metaphysis) and oncological treatment concept (chemotherapy/radiotherapy) are key factors significantly influencing the surgical technique in terms of functional outcome and longevity of the reconstruction. CONCLUSION: Surgical treatment of bone sarcoma requires broad-based experience of the oncological surgeon. Knowledge of the different surgical technics and reconstruction methods is decisive to offer the individual patient the best oncological and functional outcome.

[Management of complications in megaprostheses]. / Komplikationsmanagement bei Megaprothesen.

BACKGROUND: Megaprostheses are frequently used after segmental resection of bone sarcomas, bone metastases, and in large osseous defects in revision arthroplasty. OBJECTIVES: The incidence of the most common complications associated the use of megaprostheses are reported. The management of complications including therapeutic recommendations are described. MATERIALS AND METHODS: The current knowledge and our own experience of complication management with the use of megaprostheses are presented. RESULTS: Prospective, randomized studies or meta-analyses on this topic are lacking. An analysis of the literature shows that beside the occurrence of a local recurrence, periprosthetic infection remains the most serious complication. Two-stage revision remains the gold standard, but a single-stage exchange of the prosthesis without removing the stems might be possible in selected cases. Infection is associated with a higher risk of secondary amputation. In contrast, mechanical failures (e.g., wear of the bushings in knee replacements and aseptic loosening of the stems) can be treated more easily. Dislocation of a proximal femur replacement can mostly be prevented by using bi- or tripolar cups. CONCLUSIONS: Complications with the use of megaprostheses can be successfully treated by revision surgery in most cases.

Cartilage replacement in dogs -- A preliminary investigation of colonization of ceramic matrices.

The objective of this study was to examine the behaviour of canine chondrocytes following colonisation of a beta-tricalcium phosphate (beta-TCP, Cerasorbâ, Curasan) matrix. In total, five of these cylinders were inoculated with 1.5 ml of cell suspension and subsequently incubated for about one week. In the second part of the experiment, another five Cerasorbâ cylinders were each studded with two cartilage chips of variable size and then incubated for about one week. The series of experiments were analyzed using cell staining and imaging techniques that included scanning electron microscopy. Cell migration onto the matrix was proven for both colonisation methods. It was observed that colonising the cylinders by pipetting cell suspension on them produced far better results, with respect to both growth rate and spreading of the cells, than did colonisation by studding with cartilage chips. A homogenous, surface-covering colonisation with predominantly living cells was demonstrated by scanning electron microscopy in the chondrocyte morphology. In comparison to cell-culture controls, there was a clearly better colonisation, with cells attached to both the material's primary grains and its micropores. The ceramic studied is well accepted by canine chondrocytes, and appears to be fundamentally well-suited as a matrix for bio-artificial bone-cartilage replacement. Additional qualitative analyses and a series of experiments aiming to accelerate cell proliferation are planned for subsequent studies.

Partial purification and characterization of the defective cyclic adenosine 3':5'-monophosphate binding protein kinase from adrenocortical carcinoma.

Previous studies with isolated adrenocortical carcinoma 494 cells from this laboratory have indicated that the lack of cyclic adenosine 3':5'-monophosphate (cyclic AMP) control in steroidogenesis in the tumor may be due to the defective cyclic AMP-dependent protein kinase enzyme system. This paper describes the partial purification of such an enzyme. Purification was achieved by precipitation of the tumor homogenate with 30 and 45% ammonium sulfate, adsorption on 3% calcium phosphate gel, and chromatography on DEAE-cellulose. Four major protein peaks were isolated. Peak 2 showed cyclic AMP-binding activity and was investigated further for its kinetic properties. In contrast to the cyclic AMP-dependent protein kinase enzyme found in the normal adrenal gland, the enzyme specifically bound cyclic AMP but failed to phosphorylate exogenous histone. It is postulated that lack of the cyclic nucleotide-dependent kinase activity of the protein kinase enzyme may be responsible for the loss of cyclic AMP-regulated corticosterone synthesis in adrenocortical carcinoma cell. It is further shown that the tumor cyclic AMP-binding enzyme undergoes endogenous phosphorylation, which indicates that it has kinase activity but it is independent of cyclic AMP.

Transgenic mice overexpressing protein kinase Cdelta in the epidermis are resistant to skin tumor promotion by 12-O-tetradecanoylphorbol-13-acetate.

To determine the role of protein kinase Cdelta in mouse skin carcinogenesis, we have developed transgenic FVB/N mouse lines expressing in the epidermis an epitope-tagged protein kinase Cdelta (T7-PKCdelta) regulated by the human keratin 14 promoter. The untreated T7-PKCdelta mice displayed excessive dryness in the skin of the tail with a variable penetrance over time. Histologically, the tail skin showed hyperplasia with evidence of hyperkeratosis. The epidermis of the rest of the T7-PKCdelta mouse was unremarkable. Despite this mild phenotype, the effects of PKCdelta overexpression on mouse skin tumor promotion by 12-O-tetradecanoylphorbol-13-acetate (TPA) were dramatic. Two independent lines of T7-PKCdelta mice (16 and 37) expressing the T7-PKCdelta transgene were examined for responsiveness to skin tumor promotion by 7,12-dimethylbenz[a]anthracene and TPA. By immunoblot analysis, the T7-PKCdelta-16 and T7-PKCdelta-37 mice showed an 8- and 2-fold increase of PKCdelta protein. The T7-PKCdelta-16 mice averaged 300% more T7-PKCdelta activity than the T7-PKCdelta-37 mice did. The T7-PKCdelta-37 mice did not manifest any difference in tumor burden or incidence. However, the reduction in papilloma burden at 25 weeks of promotion for the T7-PKCdelta-16 mice relative to wild-type mice averaged 72 and 74% for males and females, respectively. The T7-PKCdelta-16 mice reached 50% papilloma incidence between 12 and 13 weeks of promotion compared with 8 weeks for wild-type mice. Furthermore, the carcinoma incidence was also reduced in T7-PKCdelta-16 mice. Carcinoma incidence at 25 weeks of promotion treatment was: wild-type females, 78%; T7-PKCdelta16 females, 37%; wild-type males, 45%; and T7- PKCdelta-16 males, 7%. Thus, PKCdelta when expressed at sufficient levels can suppress skin tumor promotion by TPA.

Primary multifocal osseous Hodgkin disease: a case report and review of the literature.

PURPOSE: Hodgkin disease (HD) typically involves the lymphatic system at one or more sites. Rarely, Hodgkin disease presents as an osseous lesion without involvement of lymph nodes. Therefore, the histologic diagnosis of osseous HD can be problematic. We present a rare case of multifocal osseous HD and a review the literature with special emphasis on treatment and prognosis. METHODS: Osteomyelitis and lymphoma are the main differential diagnoses and can only be excluded histologically by the presence of Sternberg Reed cells or by immunohistochemical examinations. This case reports a 21-year old man with a Hodgkin lymphoma located at the proximal femur and the proximal tibia. RESULTS: Staging studies revealed no other tumor manifestations. Regarding the Ann Arbor classification, the presented case should be a stage IV disease. The patient is without evidence of disease 4 years after curettage, local radiation therapy, and systemic chemotherapy despite the poor prognosis considering the Ann Arbor classification. CONCLUSION: Reviewing the few reported cases, osseous HD must be distinguished from systemic HD with diffuse bone marrow involvement and from osseous metastases in advanced stage of disease because it seems to have a better prognosis.

Rotationplasty type BI versus type BIIIa in children under the age of ten years. Should the knee be preserved?

Type BI rotationplasty is currently indicated for children with tumours of the proximal femur whereas type BIIIa rotationplasty is reserved for those in which the entire femur has to be removed. Our aim was to compare these two types of rotationplasty and determine whether the knee should be preserved in children with tumours of the proximal femur. We compared the post-operative complications, oncological outcome, range of movement, Enneking score and radiographs of six children, who had undergone type BI rotationplasty with those of 12 who had undergone type BIIIa rotationplasty. Patients with type BI rotationplasty had a mean Enneking score of 21.6 compared with 24.4 in those with type BIIIa rotationplasty, and worse mean results in all of the parameters investigated. We conclude that type BI rotationplasty has a worse functional outcome and more complications than type BIIIa rotationplasty in children under the age of ten years.

Purification and characterization of adrenocortical adenosine 3',5'-monoposphate-dependent protein kinases.

In this manuscript we describe in detail the purification and biochemical and immunological characterization of cAMP-dependent protein kinases in bovine adrenal cortex, rat adrenal gland, and isolated fasciculata cells of the rat. DEAE-cellulose chromatography of bovine adrenal cortex extract yielded two major (type I and type II) cAMP-dependent protein kinase peaks and one minor cAMP-binding peak. The minor peak (peak A) eluted at 30-80 mM NaCl and corresponded to the typical type I tetrameric structure of the holoenzyme. Peak B, eluting at 80-130 mM NaCl, comprised 10-15% of the total cAMP-binding activity and was identified as dimeric type I cAMP-binding regulatory subunit of the enzyme. Peak C (major peak) eluting at high salt (130-220 mM NaCl), was different from the typical type II holoenzyme; its mol wt was relatively low (123,000), and its cAMP-binding subunit was type I rather than type II. The native enzyme contained dimeric cAMP-binding regulatory subunit and suggested the presence of only a single catalytic subunit. Based on these results and on the reduced activation of its kinase activity by cAMP, we suggest a type I trimeric structure, R I2 C, of this enzyme. Most of the bovine adrenocortical extracts (62 of 68) did not contain type II cAMP-binding regulatory subunit of the enzyme. When present, its concentration (free or part of the holoenzyme) was less than 15% of the total cAMP-dependent protein kinases. These results were further supported by the studies with rat adrenal glands and isolated fasciculata cells derived from these glands, where only the type I cAMP receptor was found. We, therefore, conclude that in contrast to the current notion, adrenal cortex contains little, if any, enzyme containing type II cAMP-binding receptor. The predominant form of the holoenzyme contains a typical type I cAMP-binding receptor, but possesses an anomalous type II-like high salt elution pattern. We suggest that the trimeric structure of this enzyme contains a typical dimeric type I cAMP-binding subunit and a single catalytic subunit, R I2 C.

Antisera to a synthetic peptide recognize native and denatured rat estrogen receptors.

Specific polyclonal antisera to the rat estrogen receptor (rER) were developed using a synthetic peptide as the antigen. The peptide corresponds to amino acids 270-284 deduced from the cloned rER cDNA and has no homology to other steroid hormone receptors. Antipeptide antisera raised in rabbits specifically recognize a 67,000 mol wt protein, shown to be the rER, in Western blot experiments. In immunoprecipitation experiments, one tested antiserum bound unoccupied as well as 17 beta-estradiol-occupied rERs, indicating that this region is exposed in both receptor forms. This antiserum shows no cross-reactivity with rat progesterone or glucocorticoid receptors. Cross-reactivity with rabbit, human, and, to a lesser extent, bovine ERs was observed.

Application of regression analysis to the hypoglycemic activities of a series of substituted benzenesulfonamidopyrimidines.

Quantitative structure-activity relationship studies have been performed on two types of sulfonamides with hypoglycemic activity. In the case of the 2-benzenesulfonamidopyrimidines, substituted in the 5 position of the pyrimidine ring a correlation between hydrophobic forces, expressed as Rm values, and the binding to serum albumin as well as to the heights of the equipotent dose has been found. In the series of 2-benzenesulfonamidopyrimidines additionally substituted in the 4 position of the benzene ring, however, a correlation between electronic parameters, expressed as the chemical shift of the anilide NH-(type IIA) and benzylamide NH-(type IIb) protons and the biological response was observed. This correlation indicated a charge-controlled second fixation of these molecules to the receptor. This is supported by the observation of stereospecificity of the blood-glucose lowering effect and also by the importance of a constant distance between the nitrogen in the side chain and the nitrogen atom in the sulfonamido group. The correlation between the logarithm of the biological response and the electric effects of the substituents is linear as long as one homologous series is considered. If the anilide and benzylamide derivatives are combined, a linear correlation can only be obtained if a dummy parameter is included which may account for differences in conformation within these two series of compounds.

Late complications of sterilization according to method.

By using a patient questionnaire, we checked the effects of two tubal sterilization procedures (high-frequency [HF] and endocoagulation techniques) in relation to late complications. In the years following high-frequency sterilization, 23 women (8.9%) had hysterectomies; in the endocoagulation group only 9 patients (2.3%) underwent hysterectomy. Patients sterilized by the unipolar high-frequency technique required one to three curettages in 7.8% of cases, whereas only 2.1% of the endocoagulation group required this procedure. Seventy-nine patients in the high-frequency group (30.9%) exhibited menstrual disorders as compared to only 45 (11.7%) in the other group. The combination of menstrual irregularities and menopausal complaints was found in 7.4% of the HF group, while only 2.8% of the endocoagulation group experienced these problems. Menopausal complaints only, without menstrual disorders, occurred in 4.7% and 3.9% of the women, respectively. Eighty-five percent of 330 patients sterilized by the Semm endocoagulation technique had no menstrual complaints or menopausal symptoms; in the HF group this was the case for 160 women (62%). Our results demonstrate that late postoperative complications arise less often in patients sterilized by endocoagulation.

Lack of an antitumoral effect of immunomodulatory galactoside-specific mistletoe lectin on N-methyl-N-nitrosourea-induced urinary bladder carcinogenesis in rats.

The aim of the present animal experiment was to study the effect of galactoside-specific lectin or agglutinin (VAA) from mistletoe (Viscum album L.) on chemically induced tumor development in the urinary bladder of rats. Since VAA has been shown to exert a remarkable immunomodulating effect, any change in tumor formation would indicate a lectin-triggered immune control of urothelial carcinogenesis in the used model. To produce vesical neoplasms the direct-acting urothelial carcinogen N-methyl-N-nitrosourea (MNU) was administered at a single intravesical dose (7.5 mg/kg body weight). Highly purified VAA was given subcutaneously twice a week at the immunomodulatory dose of 1 ng/kg body weight over a period of 6 months during the critical phases of tumor development. After a total experimental time of 15 months the incidence of epithelial bladder tumors was 29.3% in controls versus 27.9% in rats additionally receiving the lectin and thus not significantly different in both experimental groups. There were, moreover, no substantial differences in the histopathologic spectrum of epithelial tumors induced, their patterns of growth, grades of cellular malignancy and local extension. The frequency and histopathology of mesenchymal bladder tumors as well as the incidence and morphology of carcinomas of the ureters and renal pelves also proved to be similar in controls and in rats treated with VAA. In conclusion, the present data provide no evidence for a modifying or even inhibitory effect of the immunomodulatory galactoside-specific mistletoe lectin on experimental urothelial carcinogenesis.

The treatment of locally recurrent chondrosarcoma: Is extensive further surgery justified?

The aim of this study was to define the treatment criteria for patients with recurrent chondrosarcoma. We reviewed the data of 77 patients to examine the influence of factors such as the intention of treatment (curative/palliative), extent of surgery, resection margins, status of disease at the time of local recurrence and the grade of the tumour. A total of 70 patients underwent surgery for recurrent chondrosarcoma. In seven patients surgery was not a viable option. Metastatic disease occurred in 41 patients, appearing synchronously with the local recurrence in 56% of cases. For patients without metastasis at the time of local recurrence, the overall survival at a mean follow-up after recurrence of 67 months (0 to 289) was 74% (5 of 27) compared with 19% (13 of 50) for patients with metastasis at or before the development of the recurrence. Neither the type/extent of surgery, site of tumour, nor the resection margins for the recurrent tumour significantly influenced the overall survival. With limited survival for patients with metastatic disease at the time of local recurrence (0% for patients with grade III and de-differentiated chondrosarcoma), palliative treatment, including local radiation therapy and debulking procedures, should be discussed with the patients to avoid long hospitalisation and functional deficits. For patients without metastasis at the time of local recurrence, the overall survival of 74% justifies an aggressive approach including wide resection margins and extensive reconstruction.

[Attachment tube for soft tissue reconstruction after implantation of a mega-endoprosthesis]. / Der Anbindungsschlauch zur Weichteilrekonstruktion nach Megaprothesenimplantation.

OBJECTIVE: To restore function and an active range of motion, and stabilize the joint after joint resection. INDICATIONS: Restoration of a joint capsule following reconstruction of a defect using a proximal humerus and femur prosthesis. Reattachment of tendons and muscles. CONTRAINDICATIONS: Acute or chronic infection. Status after cured infection. SURGICAL TECHNIQUE: The attachment tube (Implantcast, Buxtehude, Germany) is attached to the joint capsule (proximal humerus and femur replacement) or directly to the prosthesis (for proximal tibial replacements) using nonresorbable Ethibond® sutures (Johnson & Johnson Medical, Norderstedt, Germany). Bone anchors are used, if the joint capsule has been completely resected. The body of the prosthesis, which has previously been attached to the shaft, is then pulled distally through the tube, and a (bipolar) head or humerus cap is placed on top of it. In the proximal humerus and femur replacement, proximal slitting of the tube may be helpful to reposition the prosthesis under vision. Following repositioning, fixation of the tube is completed ventrally and the slits previously made in the tube are sutured. Fixation of the tube to the prosthesis is carried out either with Ethibond® sutures placed around the tube, or--for a proximal humerus and tibia replacement--it is possible to attach suture material to the prosthesis through eyelets. POSTOPERATIVE MANAGEMENT: Further treatment basically depends on the location of the mega-endoprosthesis used. RESULTS: Macroscopically and microscopically, fibroblasts migrate into the tube's mesh, so that attachment of the soft tissue takes place. As of yet, no cases of luxation have occurred when the tube is used in combination with a bipolar head, and with fixed-implant cups the risk of luxation can be reduced using tripolar cup systems. In patients with a proximal tibial replacement, active straightening of the knee joint can be restored in most cases, although some limitation on active extension is still possible depending on the extent of the tumor resection.