Durom™-Hip-Oberflächenersatz am Hüftgelenk: Erste klinische Ergebnisse mit dem lateralen Zugang

INTRODUCTION

We present the first clinical and radiographic results of the Durom Hip Resurfacing prosthesis with a lateral approach.

MATERIALS AND METHODS

52 patients (n = 59 protheses) with a mean follow-up of 25.4 +/- 10 month were evaluated. Clinical evaluation was done using the Harris hip score (HHS), a modified University of California at Los Angeles (UCLA) Activity Level Scale and the Merle d'Aubigné Score pre- and postoperatively. Radiographic evaluation included the preoperative femoral neck-shaft angle, the pre- and postoperative femoral offset, the postoperative stem-shaft angle as well as postoperative periprosthetic radiolucencies.

RESULTS

Within the clinical follow-up the postoperative mean HHS (93 +/- 4.3 vs. 41.2 +/- 7.1 points), the modified UCLA (8.8 +/- 2.8 vs. 4.8 +/- 1.9) as well as the Merle d'Aubigné Score (17.1 +/- 1.7 vs. 7.5 +/- 2.1) indicated a significant improvement (p <or= 0.05) compared to the preoperative evaluation. In 98.2 % a firm bony ingrown of the components without any radiolucency was observed. The average deviation of the preoperative physiological femoral neck-shaft angle (135.5 +/- 3.4 degrees) compared to the postoperative stem-shaft angle (141.3 +/- 4.8 degrees) was 5.8 +/- 2.6 degrees. The mean postoperative femoral offset was reduced by 2.5 mm. At follow-up 2 hips (3.5 %) were revised due to femoral neck fracture (n = 1) and to heterotopic ossifications (Brooker III) (n = 1).

CONCLUSION

The Durom Hip Resurfacing prosthesis is a promising alternative for the young and active patient. The real medical and economical benefit has to be evaluated in further examinations.

Improvement of the long-term adhesive strength between bone cement and bone in cemented cup arthroplasty: ex-vivo study

INTRODUCTION

One of the main causes of cup loosening in cemented total hip replacement is the lack of a hydrolysis stable compound between the hydrophobic bone cement and the hydrophilic acetabular bone stock. Thus, the long-term adhesive strength between bone and bone cement is decreased resulting in premature aseptic loosening. Accordingly, an amphiphilic bonding system was developed to prevent hydrolytic debonding in the interface bone-to-bone cement.

MATERIALS AND METHODS

Polyethylene cups were cemented in cadaver sheep hips. The hips were prepared with (n = 10) a multilayer bonding system as well as with an improved monolayer bonding system with (n = 10) and without (n = 10) UV-light hardening. The hips were dynamically loaded (10(6) cycles; 3 Hz; upper/lower load 1,500/200 N) and afterwards turned out with a defined strength to determine the interface compound strength. Dynamically loaded cemented cups without using the bonding system (n = 10) function as a control group.

RESULTS

The interface adhesive strength improved significantly by a factor of 1.9 (using the multilayer bonding system) compared to the unconditioned ones (P < or = 0.05); for the monolayer bonding system without (with) UV-light hardening the compound strength was 11.9-fold (> or =22.2-fold) higher (P < or = 0.001).

CONCLUSION

The bonding system significantly improves the adhesive strength between bone and bone cement in cemented cup arthroplasty.

[Immunohistochemical analysis of periprosthetic osteolysis in aseptic loosening of hip arthroplasty]

AIMS

The main complication in total hip arthroplasty is aseptic loosening. Wear-induced inflammatory processes lead to periprosthetic granulation tissue, which induces bone degradation due to aseptic osteolysis. At the site of bone degradation,the cell populations have not been further analysed so far. Therefore, the present study was designed to analyse bone degradation tissue in comparison to periprosthetic granulation tissue.

METHODS

Tissue specimens of 14 patients with failed modular cup components of cementless total hip arthroplasties were obtained during revision surgery. Immunohistochemistry was performed by using anti-CD 31 (endothelial cells),anti-CD 45 (granulocytes and lymphocytes) and anti-CD 68 antibodies (mononuclear phagocyte system, MPS). Fibroblasts and osteoblasts were immunohistochemically distinguished as CD 31/45/68-negative cells. Semiquantitative analyses,including a morphometric study, were then performed both in the bone degradation zone and in the periprosthetic granulation tissue.

RESULTS

At the site of bone degradation, the majority of cells belonged to MPS (73.6 +/- 3.31%),while fibroblasts were significantly less frequent (9.6 +/-1.67%). A distinct population of endothelial cells (7.75+/- 1.4%) as well as lymphoplasmacellular cells (5.75+/-2.35%) were observed. In addition,only a small amount of neutrophilic granulocytes (0.7 +/- 0.4 %) were detected. In the periprosthetic granulation tissue, findings were very similar to those of the bone degradation zone,with the exception of higher amounts of fibroblasts (15.69 +/- 2.74%).

CONCLUSIONS

This study confirms that, in aseptic hip arthroplasty loosening, the majority of cells detected at the site of bone degradation are of the MPS, which are predominantly involved in osteolytic processes. There is no pathologically significant difference between the cell population of periprosthetic granulation tissue and granulation tissue at the sites of bone degradation.

[The morse taper junction in modular revision hip replacement]

Morse taper junctions of modular hip revision replacements are predilection sites for fretting, crevice corrosion, dissociation and breakage of the components. In this report we present the results of a retrieval analysis of a morse taper junction of a MRP-titanium modular revision replacement (MRP-Titanium, Peter Brehm GmbH, Weisendorf, Germany) after 11.5 years of in vivo use. In the context of this case report the significance of morse taper junctions in modular hip revision replacement under consideration of the current literature is also discussed.

Die Behandlung femoropatellarer Knorpelschäden mit einem dreidimensionalen Kollagengel: Klinische Ergebnisse im Zwei-Jahres-Verlauf

AIM

Here we present first clinical results of the treatment of patellofemoral cartilage lesions with a 3D collagen gel (CaReS).

METHODS

Isolated patellofemoral cartilage lesions in 14 patients (13 patellar, 1 trochlear) were treated by matrix-based ACT using a collagen gel seeded with autologous chondrocytes. In this study, only those patients were taken into account who complied with the inclusion criteria of the German working group "tissue regeneration and tissue substitutes". Data were analysed in accordance with the ICRS criteria and the Brittberg score. We present the 2-year postoperative clinical follow-up.

RESULTS

After 2 years the ICRS-IKDC and Brittberg scores revealed a statistically significant improvement. The preoperative rating of the objectiveIKDC and functional ICRS score improved from 0/14 and 2/14 (14.3%) to 11/14 (78.6%) in the categories A/B and I/II, respectively. 11 Patients(78.6%) judged the clinical outcome as excellent or good. The subjective IKDC score improved from 32.4 +/- 8.4 prior to operation to 67.8 +/- 27.4 at the 2-years follow-up.

CONCLUSION

The use of 3D matrix systems could represent a promising improvement of conventional ACT in the treatment of patellofemoral cartilage lesions, but the results have to be verified by long-term investigations.

In vivo cultivation of human articular chondrocytes in a nude mouse-based contained defect organ culture model

The nude mouse model is an established method to cultivate and investigate tissue engineered cartilage analogues under in vivo conditions. One limitation of this common approach is the lack of appropriate surrounding articular tissues. Thus the bonding capacity of cartilage repair tissue cannot be evaluated. Widely applied surgical techniques in cartilage repair such as conventional and three-dimensional autologous chondrocyte implantation (ACI) based on a collagen gel matrix cannot be included into nude mouse studies, since their application require a contained defect. The aim of this study is to apply an organ culture defect model for the in vivo cultivation of different cell-matrix-constructs. Cartilage defects were created on osteochondral specimens which had been harvested from 10 human knee joints during total knee replacement. Autologous chondrocytes were isolated from the cartilage samples and cultivated in monolayer until passage 2. On each osteochondral block defects were treated either by conventional ACI or a collagen gel seeded with autologous chondrocytes, including a defect left empty as a control. The samples were implanted into the subcutaneous pouches of nude mice and cultivated for six weeks. After retrieval, the specimens were examined histologically, immunohistochemically and by cell morphology quantification. In both, ACI and collagen gel based defect treatment, a repair tissue was formed, which filled the defect and bonded to the adjacent tissues. The repair tissue was immature with low production of collagen type II. In both groups redifferentiation of chondrocytes remained incomplete. Different appearances of interface zones between the repair tissue and the adjacent cartilage were found. The presented contained defect organ culture model offers the possibility to directly compare different types of clinically applied biologic cartilage repair techniques using human articular tissues in a nude mouse model.

Das Verletzungsmuster nach Einführung der A-Junioren-Fußball-Bundesliga in Deutschland im Vergleich zum Senioren-Profi-Fußball

In 2003 the junior soccer premier league (U19) has been introduced in Germany to increase the competitive level in this group of age (16 - 18 years). It is the aim of this study to compare the injury pattern accompanying this new league of semi-professional junior soccer with a professional senior team. In a retrospective study all traumatic and overuse injuries, responsible for absence from practice or matches, which occurred in two seasons of one junior premier league team were recorded and analyzed. These data were compared to the injury pattern of a professional senior team based on a one-season survey. Overall, more traumatic than overuse injuries were seen. The lower extremity was predominantly affected by both. The ankle joint was the most injured joint. An injury rate of 2.89 per 1000 hours of soccer was calculated for the juniors and 2.35 for the seniors. Junior players missed 15.8 days and seniors 17.1 days of practice or match as result of an injury. Semi-professional junior and professional senior soccer share the same injury patterns with regard to injury rates and types of injuries. Therefore a professional medical care with special emphasis on prophylaxis is warranted in semi-professional junior soccer.

[First clinical experiences with a novel 3D-collagen gel (CaReS) for the treatment of focal cartilage defects in the knee]

AIM

In this prospective study we present a novel technique of matrix-based chondrocyte transplantation for the treatment of focal cartilage defects.

METHOD

22 patients with chondral or osteochondral femoral defects were treated with 3D-collagen type-I gel seeded with autologous chondrocytes (CaReS). Overall handling of this novel method is described, and results after 2 years follow-up with regard to the ICRS-score are presented.

RESULTS

14 patients were treated because of a focal chondral lesion, in 8 cases subchondral bone had to be reestablished. The average defect size was 6 cm(2). In all cases cell-seeded matrix samples could be fixed with fibrin glue without any problems. The average surgery time was 69 min, length of the surgical approach was 8.2 cm. No surgery-specific problems had to be observed. A significant improvement in IKDC-score, functional score and overall rating after 3 or 6 months up to 2 years follow-up was detected. After 2 years post-OP 13 Patients were evaluated and matrix-based defect treatment by CaReS was rated good to excellent by 84.6 % of the patients.

CONCLUSION

Defect treatment with cell-seeded 3D-collagen gel is easy to handle with a good clinical outcome after 2 years follow-up. Further investigations with higher patient number, longer follow-up time and histological and biomechanical sample analysis are needed in order to establish this method as an improvement of conventional ACT.

[Cemented total knee arthroplasties]

INTRODUCTION

The aseptic loosening of cemented total knee arthroplasties is still an unsolved problem. In this regard, the hydrolysis resistance in the metal-to-bone cement interface is of major importance.

MATERIAL AND METHODS

Cemented pre-treated tibia components coated by means of a silica/silane interlayer system of the model "Columbus PS" were dynamically loaded with the help of a knee-simulator similar to DIN ISO 14243. After loading, the components were microscopically analysed concerning debonding in the metal-to-bone cement interface as well as with regard to cement mantle defects. These data were matched with uncoated "Columbus PS" components. Unloaded coated and uncoated tibia components acted as a control.

RESULTS

In comparison with uncoated tibia components, the pre-treated and coated ones yielded a highly significant reduction of cement defects (p < 0.01) as well as a significant reduction of debonding in the metal-to-bone cement interface (p < 0.05).

CONCLUSION

By means of the silica/silane interlayer system for cemented tibia components, a hydrolytic debonding in the metal-to-bone cement interface with subsequent mechanical loosening and consecutive early cement mantle failure can be significantly reduced. This could lead to an increased long-term stability of the metal-to-bone cement compound with decreased aseptic loosening in clinical use.

[Liver laceration following a kick in a soccer game]

Severe intraabdominal injuries in soccer are very rare. We present the case of an 18 year old soccer player who suffered from a grad IV liver laceration following a kick during a soccer game. After primary explorative laparatomy and liver packing in a hospital nearby the patient was transferred to our clinic. Following CT scan the injury was treated by suture of liver parencym lacerations, argon laser coagulation and pile duct repair. In soccer severe intraabdominal injuries should be expected following players collision at high velocity or kicking with the foot or the knee.

[Isolated bilateral Sternocostoclavicular Hyperostosis (SCCH) with a pathological clavicular fracture--a 10-year follow-up]

The presented case demonstrates the clinical and radiological course of a woman suffering from bilateral sternocostoclavicular hyperostosis (SCCH) from early changes to a spontaneous clavicula fracture after 10 years. SCCH is characterised by a chronic recurrent painful swelling of the sternoclavicular region due to an aseptic inflammation and hyperostosis of the clavicula, sternum, upper ribs and the adjacent soft tissues. Frequently the picture is accompanied by cutaneous and other skeletal symptoms. The disease can be part of the SAPHO (synovitis, acne, pustulosis, hyperostosis, osteitis) syndrome. The chronic process is represented by the typical "bull horn sign" in a bone scan. NSAIDS should represent the first line treatment.

[Coxitis fugax--the beginning of Perthes' disease?]

We present the clinical case of a decennial boy with acute leftsided hip pain without appropriate trauma. The initial diagnosis of coxitis fugax was verified in this case with inconspicuous blood parameters and X-ray by a sonographically proven intraarticular effusion. An immediate magnet resonance imaging (MRI) study of the affected hip joint was done. Here, a complete "necrosis" of the proximal femur epiphysis was verified. With knowledge of these results, an immediate operation of the hip joint with a ventral capsule incision and consecutive intraarticular decompression was performed. A complete reperfusion of the femur head was evident in the MRI scan seven days postoperatively. In accordance with this clinical case report, we would like to point out the necessity for the immediate diagnosis of indifferent hip pain by means of MRI, especially for patients in the atypical "critical age" (> or = 8 years) for coxitis fugax. This is discussed under consideration of the possible aetiopathogenesis and the current literature.

Comparison of modern marker proteins in serum and synovial fluid in patients with advanced osteoarthrosis and rheumatoid arthritis

Numerous studies have focused on the significance of modern marker proteins in the synovial fluid of the knee joint and in the serum both, for osteoarthritis (OA) and rheumatoid arthritis (RA). The relationship between the serum concentrations and the concentrations in the synovial fluid is still unclear. Synovial fluid and serum samples were obtained from 13 patients with advanced OA and from 8 patients with severe RA and concentrations of MMP-1, MMP-3, MMP-13, TIMP-1, COMP and MIA/CD-RAP were determined. All values were normalized against the total protein concentrations. Serum concentrations of MMP-13 in the RA-group were statistically higher than the synovial values (P<0.05). MMP-13 was the only marker protein that revealed distinct higher levels in the serum than in the synovial fluid. The study design allows only conclusions about advanced stages of RA and OA. Longitudinal investigations may provide further information about the value of MMP-13 as a potential marker to monitor the course of RA and OA.

Diagnostic values of positron emission tomography versus triple-phase bone scan in hip arthroplasty loosening

INTRODUCTION

The most frequent complications of total hip arthroplasty are septic and aseptic wear-induced loosening. A reliable differentiation between septic and aseptic loosening with current diagnostic tools is not possible. Therefore, we examined the diagnostic valency of positron emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG) in cases of septic or aseptic hip arthroplasty loosening compared with conventional triple-phase bone scan (TPBS).

MATERIALS AND METHODS

Fifty patients with 70 total hip replacements (symptomatic n=50, asymptomatic n=20) were examined by means of FDG-PET and TPBS to detect septic and aseptic loosening and differentiate between the two. A differentiated algorithm subdivided into categories I-V was developed for FDG-PET. Additionally, standardized uptake values (SUV) were calculated from the lesion with the highest FDG uptake. Interpretations of the TPBS were done according to the criteria described by Wilson. The final diagnosis was based on operative findings including microbiological and histological examinations (n=50), while the remaining asymptomatic arthroplasties (n=20) were integrated into a clinical follow-up (> or =9 months).

RESULTS

Sensitivity/specificity of FDG-PET was 91%/92% (accuracy 91%) compared with 78%/70% (accuracy 74%) for TPBS. A high correlation could be proved between FDG-PET investigation and operative histopathological findings (r(Spear)> or =0.9). No significant differences were found regarding cemented and uncemented implanted hip arthroplasties (p> or =0.05). Calculation of the SUV turned out to be inappropriate as a sole criterion for image interpretation.

CONCLUSION

FDG-PET is a promising, highly accurate examination method to detect polyethylene and metal wear-induced chronic inflammation followed by periprosthetic osteolysis. In addition, FDG-PET has a significantly higher sensitivity and specificity than TPBS for differentiating between aseptic loosening and infection.

Radionuclide imaging of the painful hip arthroplasty: positron-emission tomography versus triple-phase bone scanning

Two major complications of hip replacement are loosening and infection. Reliable differentiation between these pathological processes is difficult since both may be accompanied by similar symptoms. Our aim was to assess the diagnostic ability of triple-phase bone scanning (TPBS) and positron-emission tomography (PET) to detect and differentiate these complications in patients with a hip arthroplasty. Both TPBS and PET were performed in 63 patients (92 prostheses). The radiotracer for PET imaging was (18)F-fluorodeoxyglucose (FDG). Image interpretation was performed according to qualitative and quantitative criteria although the final diagnosis was based upon either surgical findings or clinical follow-up. The sensitivity, specificity and accuracy of PET was 0.94, 0.95 and 0.95 respectively, compared with 0.68, 0.76 and 0.74 for TPBS. We found that an image interpretation based exclusively upon quantitative criteria was inappropriate because of its low selectivity. The histological examination indicated that increased periprosthetic uptake of FDG in patients with aseptic loosening was caused by wear-induced polyethylene particles and the subsequent growth of aggressive granulomatous tissue.

Das Verletzungsrisiko im Jugend- und Juniorenwettkampfkarate

Increasing professionalism in competitive karate has led to a specific injury pattern. The aim of our study was to investigate the injury pattern in junior competitive karate and to evaluate the prophylactic effect of fist padding. During the 4 (th) Junior World Championships of the World Karate Confederation (WKC) 2004 235 karate fights were observed and injury-related data were recorded. Fist padding was used in 183 fights, 52 fights were carried out without. In 22 % of all fights we saw an injury. Most of them were mild injuries of the head and face: 32 bruises of the face (13 with epistaxis), 7 facial lacerations and 3 concussions (mild brain injury). 14 fights were stopped due to an injury. Only in the category male 18 - 20 years a higher rate of injuries was seen without fist padding (shobu ippon) compared to shobu sanbon (with fist padding). The injury pattern of junior competitive karate is comparable to senior karate. Fist padding does not generally reduce the incidence or severity of injuries.

Welche Faktoren beeinflussen das Ergebnis der ACT bei Überschreiten der Indikationsgrenzen?

AIM

The present study evaluates the results of ACT at the knee joint with transgression of the usual spectrum of indications and points out the possible limits of the method.

METHODS

In 20 of a total of 71 patients the indication limits of ACT were exceeded. The clinical follow-up over two years was related to the localisation, size, adjacent cartilage, previous and additional operations and the quality of the transplanted chondrocytes.

RESULTS

The average patient age at time of operation was 41.1 years (24 to 55 years). The average defect size was 7.9 cm (2) (3.75 to 14 cm (2)). In the analysed group outside of the indication limits of ACT half of the patients showed good or excellent results at clinical follow-up after 2 years. 10 patients, however, assessed the clinical situation as fair or poor. Within this group 5 patients showed a minimum of two lesions. In 6 patients the treated defect was not completely surrounded by an adjacent cartilage shoulder. In 7 cases the meniscus at the site of the lesion had been partially removed in a previous operation and osteoarthrosis or kissing lesions were detected in 4 cases. The persistent good cell quality had no negative influence on the postoperative results.

CONCLUSION

The results after ACT are influenced by the adjacent cartilage shoulder, kissing lesions, previous meniscectomy and osteoarthrosis. This may limit the indications of the method.

[Meniscus replacement: current aspects in the field of tissue engineering]

Tissue engineering offers new opportunities for meniscus repair and replacement. In this field different approaches are being studied to genererate a meniscus subsitute by a combination of a matrix scaffold, cells and specific stimuli. MENISCUS REPLACEMENT BY ACELLUAR MATRICES: For meniscus replacement the matrix material has to meet high biomechanical demands. Besides implant geometry, the material properties and a secure intraarticular attachment are important preconditions for implant function. A collagen scaffold has already been applied clinically for partial meniscus replacement. Scaffolds made of synthetic, bioabsorbable polymers and small intestine submucosa have been employed in animal studies. Following implantation, matrices are invaded by cells and undergo a process of remodeling. Formation of fibrocartilage repair tissue has been observerd. The biomechanical quality of implants and their effect on cartilage preservation have to be studied further. CELLULAR SEEDING OF MATRICES FOR MENSICUS REPLACEMENT: Advanced biological and biomechanical implant quality might be achieved by seeding matrices with cells in vitro. However, the ideal type of cell for this purpose has not yet been identified. Autologous mensicus cells, articular chondrocytes and mesenchymal stem cells represent possible cellular sources. Additional stimuli, such as cytokines and mechanical forces, and techniques of genetic engineering might further contribute to enhance the quality of engineered tissue.

Die zementfreie modulare MRP-Hüftrevisionsschaftendoprothese im „klinischen Follow-up”

INTRODUCTION

We present prospective medium-term results of the modular revision prostheses "MRP-TITANIUM".

MATERIAL AND METHODS

45 patients (n = 48 prostheses) were evaluated. The mean follow-up was 4.7 years (min.-max.: 1.0-9.0 years). Pre- and postoperatively the Harris hip score (differentiated to Paprosky I-III) was examined. 66.67 % of the cases had extensive bony defects (> or = Paprosky II b). By means of X-ray examinations, the stability of the prostheses, periprosthetic bone remodelling, the presence of radiolucent lines as well as bone defect regeneration were assessed postoperatively.

RESULTS

The mean Harris hip score improved from 25.6 preoperative to 71.4 postoperative (p < or = 0.05). In 44 cases the X-ray showed stable fixation without secondary migration. In one case the stem (stand time 2.36 years) was revised due to secondary migration (> or = 5 mm). The survival rate (Kaplan-Meier) was 97 %. Bone transplantation with consecutive defect regeneration was (n = 30) complete in all cases. In six cases (12.5 %) a postoperative dislocation occurred with subsequent successful closed reposition four times (8.3 %). In two cases (4.2 %) an open reposition was done with correction of the antetorsion angle of the prostheses.

CONCLUSION

The "MRP-TITANIUM modular revision prostheses" has proved to be reliable in cases of revision surgery with extensive bony defects. The failure rate was 2.1 % for 48 prospectively examined prostheses.

[[F-18]-fluorodeoxyglucose (FDG) positron emission tomography (PET) as a diagnostic for hip endoprosthesis loosening]

AIM

The purpose of this study was to examine the FDG-PET in respect of its diagnostic valency with regard to septic/aseptic loosening of lower limb prostheses.

METHOD

28 patients with 41 lower limb prostheses were examined by means of FDG-PET to evaluate septic/aseptic loosening of their hip prostheses. Therefore, a differentiated FDG-PET result interpretation subdivided into five categories was developed. The final diagnosis was based on operative findings with following culture and histological outcome.

RESULTS

The worked-out categories showed a high agreement to the intraoperative macroscopic and histological results (n = 23 correctly positive, n = 1 false positive, n = 1 correctly negative and n = 3 false negative).

CONCLUSION

With a subtly differentiated interpretation (categories I - V) of the qualitative glucose metabolism safe statements can be made regarding septic/aseptic endoprostheses loosening. This was impressively confirmed by the agreement of the FDG results with the histological results.

[Competitive karate and the risk of HIV infection--review, risk analysis and risk minimizing strategies]

Bleeding facial injuries are not uncommon in competitive karate. Nevertheless, the risk of an infection with HIV is extremely low. Guidelines about the prevention of HIV infections are presented. Especially in contact sports and martial arts the athletes, judges and staff have to recognize and employ these recommendations. Bleeding wounds of the hands due to contact with the opponents teeth can be minimized by fist padding.

[Teutschländer disease. A rare benign differential diagnosis of proliferative space-occupying lesions in the periarticular soft tissue]

The tumoral calcinosis (synonym: Teutschländer disease) is a very rare benign metabolic dysfunction of unknown etiology. It manifests principally as massive subcutaneous soft tissue deposits of calcium phosphate near the large joints and is also characterized by slow progressive growth. Causally, a disturbance of the calcium and phosphate metabolism/balance with, among others, autosomal dominant heredity is suspected. It appears frequently in the black African population in all age groups, but preferentially in the 1st and 2nd decades of life. Medical help is most frequently sought because of increasing tumor size causing displacement and consecutive pain as well as decreased joint play. We present here a case of Teutschländer disease in a 50-year-old woman on long-term hemodialysis and describe the clinical, radiological, and pathological signs of this rare disease. Subsequently, speculative etiology, differential diagnostic considerations as well as the therapeutic interventions for tumoral calcinosis are discussed taking into consideration the current literature.

[Analysis of (18)F-FDG uptake patterns in PET for diagnosis of septic and aseptic loosening after total hip arthroplasty]

AIM

Identification of typical patterns for fluorodeoxy-glucose (FDG) uptake in positron emission tomography (PET) to detect aseptic loosening of hip prosthesis (ace-tabular and/or femoral component) and prosthetic infection.

METHODS

18 patients with painful hip prosthesis underwent PET using a dedicated full ring scanner after application of 200-300 MBq FDG. The interface between bone and surrounding soft tissue or bone as displayed on coronal slices was divided into 12 segments in accordance with the classifications of Delee and Gruen. FDG uptake in each of the segments was scored (0-3) by two independent observers. Intraoperative findings were regarded as the gold standard.

RESULTS

After surgical revision 14 acetabular components and 9 femoral components were found to be loose and prosthetic infection was present in 7 prostheses. Loosening of the acetabular component was correlated to enhanced uptake in the middle of the acetabular interface, while loosening of the femoral component was correlated to enhanced uptake in the proximal and middle segment of the lateral femoral interface and the proximal segment of the medial femoral interface. A similar pattern was found in prosthetic infection with high uptake along the middle portion of the lateral femoral interface. In 6 of 7 infected prostheses loosening of the acetabular and of the femoral component was present. Taking the typical uptake patterns as criteria for loosening and grade 3 uptake as an additional criterion for septic loosening the accuracy of PET imaging in the detection of loosening of the acetabular or the femoral component and of prosthetic infection was 72, 78 and 89%, respectively.

CONCLUSION

This pilot study presents FDG-PET as a promising diagnostic tool for patients with painful hip prostheses. Its clinical value should be evaluated in a larger patient population.

[FDG PET as an early nuclear medical diagnostic tool for aseptic wear-induced loosening of hip joint endoprostheses--a report of two cases]

To date, 2-[F-18]fluoro-2-deoxy-D-glucose PET (FDG PET) is used as a tool in oncology as well as myocardiological and cerebral functional diagnostics in the clinical routine. False positive results of tumor search imply new possibilities for use in diagnostics of inflammation. The two case reports presented here on aseptic loosening of endoprostheses caused by the rub of polyethylene with histological and immunohistological refurbishing call attention to the possible diagnostic valency of FDG PET as an early warning system regarding aseptic artificial limb loosening induced by the rub of polyethylene. By quantification of glucose metabolism with the "standard uptake value" (SUV) as well as specific storage samples from around the artificial limb, it is the aim of our study group in further examinations to develop an algorithm which permits to distinguish between septic and aseptic loosening.

[Acute retrocecal appendicitis caused by an Actinomyces israelii mixed infection]

We report the rare case of a retrocecal appendicitis in an adult caused by an Actinomyces israelii mixed infection. Suspecting an acute appendicitis the explorative laparotomy was performed. Appendectomy with extensive drainage of the abscess and subsequent high-dose penicillin therapy over several months were the definitive treatment, resulting in complete healing. Special features of clinical symptomatology and problems concerning diagnosis and differential diagnosis are discussed.