Factors associated with non-participation and dropout among cancer patients in a cluster-randomised controlled trial.

We investigated the impact of demographic and disease related factors on non-participation and dropout in a cluster-randomised behavioural trial in cancer patients with measurements taken between hospitalisation and 6 months thereafter. The percentages of non-participation and dropout were documented at each time point. Factors considered to be potentially related with non-participation and dropout were as follows: age, sex, marital status, education, income, employment status, tumour site and stage of disease. Of 1,338 eligible patients, 24% declined participation at baseline. Non-participation was higher in older patients (Odds Ratio [OR] 2.1, CI: 0.6-0.9) and those with advanced disease (OR 2.0, CI: 0.1-1.3). Dropout by 6 months was 25%. Dropout was more frequent with increased age (OR 2.8, CI: 0.8-1.2), advanced disease (OR 3.0, CI: 1.0-1.2), being married (OR 2.4, CI 0.7-1.1) and less frequent with university education (OR 0.4, CI -1.3 to -0.8) and middle income (OR 0.4, CI -0.9 to -0.7). When planning clinical trials, it is important to be aware of patient groups at high risk of non-participation or dropout, for example older patients or those with advanced disease. Trial designs should consider their special needs to increase their rate of participation.

[Are Higher Prices for Larger Femoral Heads in Total Hip Arthroplasty Justified from the Perspective of Health Care Economics? An Analysis of Costs and Effects in Germany]. / Sind höhere Preise für größere Kopfdurchmesser in der Hüftendoprothetik medizinökonomisch vertretbar? Eine Analyse der Kosten und Effekte in Deutschland.

Background: In total hip arthroplasty (THA), femoral head diameter has not been regarded as a key parameter which should be restored when reconstructing joint biomechanics and geometry. Apart from the controversial discussion on the advantages and disadvantages of using larger diameter heads, their higher cost is another important reason that they have only been used to a limited extent. The goal of this study was to analyse the price structure of prosthetic heads in comparison to other components used in THA. A large group of patients with hip endoprostheses were evaluated with respect to the implanted socket diameter and thus the theoretically attainable head diameter. Materials and Methods: The relative prices of various THA components (cups, inserts, stems and ball heads) distributed by two leading German manufacturers were determined and analysed. Special attention was paid to different sizes and varieties in a series of components. A large patient population treated with THA was evaluated with respect to the implanted cup diameter and therefore the theoretically attainable head diameter. Results: The pricing analysis of the THA components of two manufacturers showed identical prices for cups, inserts and stems in a series. In contrast to this, the prices for prosthetic heads with a diameter of 36-44 mm were 11-50 % higher than for 28 mm heads. Identical prices for larger heads were the exception. The distribution of the head diameter in 2719 THA cases showed significant differences between the actually implanted and the theoretically attainable heads. Conclusion: There are proven advantages in using larger diameter ball heads in THA and the remaining problems can be solved. It is therefore desirable to correct the current pricing practice of charging higher prices for larger components. Instead, identical prices should be charged for all head diameters in a series, as is currently established practice for all other THA components. Thus when reconstructing biomechanics and joint geometry in THA, it should be possible to recover not only leg length, femoral offset and antetorsion of the femoral neck, but also to approximately restore the diameter of the femoral head and thereby optimise the functional outcome.

A pilot trial comparing the tear-out behavior in screw-sockets and cemented polyethylene acetabular components - a cadaveric study.

BACKGROUND: The removal of well-fixed acetabular components following THA (total hip arthroplasty) is a difficult operation and could be accompanied by the loss of acetabular bone stock. The optimal method for fixation is still under debate. The aim of this pilot study was to compare the tear-out resistance and failure behavior between osseo-integrated and non-integrated screw cups. Furthermore, we examined whether there are differences in the properties mentioned between screw sockets and cemented polyethylene cups. HYPOTHESIS: Tear-out resistance and related mechanical work required for the tear-out of osseo-integrated screw sockets are higher than in non-integrated screw sockets. PATIENTS AND METHODS: Ten human coxal bones from six cadavers with osseo-integrated screw sockets (n=4), non-integrated (implanted post-mortem, n=3) screw sockets and cemented polyethylene cups (n=3) were used for tear-out testing. The parameters axial failure load and mechanical work for tear-out were introduced as measures for determining the stability of acetabular components following THA. RESULTS: The osseo-integrated screw sockets yielded slightly higher tear-out resistance (1.61±0.26kN) and related mechanical work compared to the non-integrated screw sockets (1.23±0.39kN, P=0.4). The cemented polyethylene cups yielded the lowest tear-out resistance with a failure load of 1.18±0.24kN. Compared to the screw cups implanted while alive, they also differ on a non-significant level (P=0.1). Osseous failure patterns differed especially for the screw sockets compared to the cemented polyethylene cups. DISCUSSION: Osseo-integration did not greatly influence the tear-out stability in cementless screw sockets following axial loading. Furthermore, the strength of the bone-implant-interface of cementless screw sockets appears to be similar to cemented polyethylene cups. However, given the high failure load, high mechanical load and because of the related bone failure patterns, removal should not be performed by means of tear-out but rather by osteotomes or other curved cutting devices to preserve the acetabular bone stock. LEVEL OF EVIDENCE: Level III, case-control-study.

[Infections of hip and knee endoprostheses. Spectrum of pathogens and the role of multiresistant bacteria]. / Infektionen von Hüft- und Knieendoprothesen. Erregerspektrum und die Rolle multiresistenter Bakterien.

BACKGROUND: Because of the rise in primary implantations in elective knee and hip arthroplasty, the number of complications, particularly due to prosthetic infections has increased. Partly due to multimorbidities, an increase in geriatric patients and often unnecessary use of antibiotics, a change in the spectrum of bacteria with an increase in multi-drug resistant pathogens is to be expected. For physicians this creates not only new medical and economic but also sociopolitical challenges. QUESTION: Has the spectrum of bacteria in prosthetic joint infections after total hip arthroplasty (THA) and total knee arthroplasty (TKA) changed during the 12-year period 2001-2012 in our hospital and what role do multi-drug resistant bacteria play? INVESTIGATION COLLECTIVE: A total of 320 patients with prosthetic joint infections (PJI) following TKA or THA could be identified and were included in this study. The sample consisted of 172 patients with an infection after THA (56 % females n = 96 and 44 % males n = 76) with a mean age of 70.9 years (range 39-92 years) and 148 patients with an infection after TKA (55 % females n = 82 and 45 % males n = 66) with a mean age of 70.7 years (range 15-87 years). The bacteria detected and the development over the course of time were evaluated. RESULTS: An increase was found in the occurrence of coagulase negative staphylococci (CNS), in particular Staphylococcus epidermidis (2001-2003 n = 10 and 2010-2012 n = 27). The proportion of oxacillin and methicillin-resistant Staphylococcus epidermidis (MRSE) was also found to increase (0 % in 2001-2003 and 74 % in 2010-2012). A substantial increase in methicillin-resistant Staphylococcus aureus (MRSA) infections could not be found and there was a tendency towards reduction in the total number of Staphylococcus aureus infections. A total of five extended spectrum beta-lactamase (ESBL)-producing bacteria were isolated. CONCLUSION: The spectrum of bacteria has only slightly changed over the years from 2001 to 2012, whereby an increase was only found in the number of CNS infections. Multi-drug resistant bacteria, in particular MRSE have increased. The changes in MRSE found in this study do not appear to warrant a general rethinking of antibiotic prophylaxis.

[Subtotal Segment Resection, Augmenting Angle-Stable Plate Osteosynthesis and Allogenic Bone Graft as Treatment Option for Juxtacortical Osteosarcoma in the Knee Region]. / Subtotale Segmentresektion, augmentierende winkelstabile Plattenosteosynthese und allogene Spongiosaplastik als Therapieoption beim knienahen juxtakortikalen Osteosarkom.

Juxtacortical osteosarcomas are a group of rare primary bone tumours. They differ from medullary osteosarcomas in their anatomic location (outside of the corticalis), low metastasis rate and better prognosis. The only evidence-based treatment of juxtacortical osteosarcomas is the wide surgical resection. In this technical report we will introduce a new surgical technique, including the subtotal resection of the tumour-bearing bone segment, defect reconstruction by means of an augmenting fixed-angle plate osteosynthesis and homologous cancellous bone graft. If necessary, a subsequent plastic coverage of the soft tissue defect was performed. The technique will be presented by means of three illustrated cases of young patients with juxtacortical osteosarcomas in the proximity of the knee joint. Following diagnostic confirmation by means of an incision biopsy and tumour staging, the three patients underwent this new surgical technique. In the postoperative follow-up and re-staging, two to seven years after surgery, all patients were under complete remission, had functionally restored knee joints (Karnofsky score 90 % or higher) and showed good aesthetic results. The surgical technique described may therefore be an adequate alternative to the complete resection of the tumour-bearing bone segment with prosthetic reconstruction and should be considered on the basis of the illustrated functional results in individual cases.

[Larger heads compensate for an increased risk of THA dislocation in high-risk patients]. / Größere Köpfe kompensieren erhöhte Hüft-TEP-Luxationsgefahr bei Hochrisikopatienten.

BACKGROUND: Dislocation is a devastating complication after total hip arthroplasty (THA) and occurs in 2-5% of primary THA cases and 5-10% of revision THA cases. Assuming correct implantation, dislocation risk can be reduced primarily by capsular repair and the use of larger prosthetic heads. However, larger heads are also associated with risks like accelerated wear or implant loosening, which is why heads with a maximum diameter of 36 mm are currently standard in primary THA. In cases with high dislocation risk, the use of 40 mm and 44 mm heads should be considered. OBJECTIVES: This study aimed to quantify THA dislocation risk and retrospectively analyze the course of disease in high-risk patients treated with 40 mm or 44 mm femoral heads after primary or revision THA, concerning dislocation and other complications suffered. MATERIALS AND METHODS: All patients with increased THA dislocation risk, treated from 2009-2014, were evaluated regarding dislocations. The cases with installation of 40 mm or 44 mm prosthetic heads were classified using a self-developed 5-level risk score and retrospectively analyzed. RESULTS: During the observation period, 288 THA interventions with increased dislocation risk were performed. In 278 cases with ball diameters ≤ 36 mm the dislocation rate was 15.1% (n=42). In 10 high dislocation-risk cases (3A to 4B according to recommended scoring system), 40 mm and 44 mm heads were used. After a 22.8 month mean follow-up, no THA dislocations were reported. CONCLUSION: Our results with 40 and 44 mm heads and the existing literature confirm much higher joint stability and, thus, significantly reduced dislocation risk with larger prosthetic heads in THA. Their use is, therefore, justified in high-risk patients and should be considered in future THA.

[Cardiac fibromyxosarcoma with bone metastases : palliative surgical treatment]. / Ossär metastasierendes Fibromyxosarkom des Herzens : Palliative operative Therapie.

This article presents the unusual case of a 58-year-old woman with a low-grade cardiac fibromyxosarcoma which was primarily surgically resected and treated with adjuvant chemotherapy. A pulmonary metastasis as well as osteolytic metastatic destruction of the right iliac crest occurred 3 years after primary diagnosis and 2 years later a bone metastasis of the left distal femur was detected. Applying a palliative treatment concept resection of the pulmonary metastasis and an extralesional resection of the bone metastasis of the right iliac crest with plastic reconstruction were performed. Afterwards resection of the left distal femur metastasis and prosthetic reconstruction with distal femur replacement could also be realized. Despite an initial poor prognosis a high quality of life without essential functional limitations could be maintained for more than 6 years in this individual case.

[Secondary telangiectatic osteosarcoma of the left femur. A case presentation of an unusual course of disease]. / Sekundäres teleangiektatisches Osteosarkom des linken Femurs. Darstellung eines ungewöhnlichen Krankheitsverlaufs.

BACKGROUND: This article presents the unusual case of a 73-year-old male patient who was treated with primary interlocking nailing after a pathological femoral fracture. DIAGNOSTICS: Despite comprehensive diagnostics including several biopsies, a tumor could not be detected. In 2008 when progressive cystic femoral destruction leading to loosening of the nail necessitated a partial femoral prosthesis, an osteosarcoma could first be diagnosed in the resected bone. THERAPY: Advanced progression of the tumor required an extended hip exarticulation. During the current restaging of the now 84-year-old patient no tumor could be detected. CONCLUSION: When a malignancy cannot be excluded even by repeated biopsies of radiologically suspicious structures, an adequate tumor staging followed by close monitoring should be carried out. For a clinically silent, long-term course of cystic destruction of a long bone over several years, an age over 60 years and a lack of distant metastases, an atypical osteosarcoma should be considered in the differential diagnosis.

[The impact of capsular repair on the dislocation rate after primary total hip arthroplasty: a retrospective analysis of 1972 cases]. / Der Einfluss der Kapselrekonstruktion auf die Luxationsrate nach primärer Hüftendoprothetik: eine retrospektive Analyse von 1972 Fällen.

BACKGROUND: Dislocation is the second most frequently encountered complication in primary total hip arthroplasty (THA) and occurs more commonly in the early postoperative rehabilitation phase. Sir Charnley recommended the "avoidance of resection of the capsule" and emphasised its contribution to hip joint stability in THA. Several authors, however, doubted its significance and considered resection of the capsule to be essential. Since 2002, some surgeons increasingly adopted a modified, less invasive technique of THA via Bauer approach, including the preservation and repair of the hip joint capsule with focus on maintaining its acetabular origin. Another group of surgeons applied the traditional technique including the resection of the joint capsule via an anterolateral approach. In this case-control study we investigated whether the dislocation rate can be reduced through joint capsule reconstruction and whether any negative impact on patient satisfaction, functional results or revision rate is observed. MATERIAL AND METHODS: All cases of primary THA performed in our institution in a timeframe between 2002 and 2009 were included with the only exceptions of resurfacing arthroplasty, dual mobility and tumour hip replacements. Joint capsule repair cases were gathered in the study group (SG), capsule resection cases in the control group (CG). Additional patient-related data were taken from the anaesthesia records. The WOMAC score and a questionnaire focusing on detection of dislocations and revision surgeries was sent out for each case. Further targeted research was conducted that included requesting records and reports from external hospitals. In the case of non-responding patients, all available data (operating room documentation, electronic files, archive, X-rays) were reviewed for incidents of dislocation and revision surgery. Groupings and classifications were exclusively performed by senior surgeons. SG and CG were compared regarding epidemiologic, implant-associated and surgery-specific data. Statistical evaluations were performed using the Chi-squared test and the Mann-Whitney U test. RESULTS: 1972 cases of primary THA were included: 992 in the SG and 980 in the CG. The follow-up rates were 92.7 % in the SG and 76.4 % in the CG, the mean follow-up times 33.5 months and 73.4 months, respectively, with a follow-up of at least 12 months in all cases. In the SG, the dislocation rate was 0.3 % (n = 3) and thus significantly lower than the 2.55 % in the CG (n = 25, p < 0.001). Both the WOMAC score (SG: 1.46 ± 1.73; CG: 1.53 ± 1.80; p > 0.05) and the revision rate (SG: 5.24 %; CG: 6.84 %; p = 0.139) showed no significant differences. CONCLUSION: Preservation and repair of the hip joint capsule causes an 88-%-reduction of the dislocation rate in primary THA in this large series including 1972 cases, operated via the Bauer or the anterolateral approach. Several authors reported comparable results after THA using similar techniques of soft tissue and capsular repair through the posterior or posterolateral approach. Sparing and reconstructing the hip joint capsule therefore seems to reduce the dislocation rate after primary THA by one order of magnitude regardless of the surgical approach and, especially, if the acetabular origin is preserved. Capsule-related specific complications such as an increased revision rate, malfunction or pain were neither recorded in our study nor by others. Thus, careful preservation and reconstruction of the hip joint capsule may be expressly recommended in primary THA.

[Multilocular Paget's disease in IBMPFD syndrome. A case report with 14-year follow-up]. / Multilokulärer Morbus Paget bei IBMPFD-Syndrom. Darstellung eines Krankheitsverlaufes über 14 Jahre.

Paget's osteodystrophia deformans is a monoostotic or polyostotic disease of the skeletal system with increased bone remodelling, structural modifications and skeletal deformation, typically arranged like a chessboard. The unusual case of a patient is described who had suffered from generalized Paget's disease of the bone for 14 years and also developed progressive myopathy and a behavioural variant frontotemporal dementia. Further cytogenetic diagnostics revealed a point mutation in the valosin-containing protein (VCP, p97) gene on chromosome 9p13-p12 consistent with the finding of inclusion body myopathy with early onset Paget's disease and frontotemporal dementia (IBMPFD syndrome). A causal therapy of this disease is not known. Conservative treatment with bisphosphonate therapy, intensive physiotherapeutic exercise and psychotherapeutic treatment was performed to retard the progression of the disease.

[The significance of the acetabular labrum for hip joint stability--an experimental study]. / Die Bedeutung des Labrum acetabulare für die Hüftstabilität--eine experimentelle Studie.

AIM: Aim of our study was to create artificial labra for joint models of different diameters (28, 32 and 36 mm) and to measure their stability potential at rest (SPR). The experiment was performed under the same conditions as a previous one with capsulated joint models. Our target was to prove the hip stabilising effect of the atmospheric pressure (AP) as well as the parameters for joint stability and to test the function of the artificial labra. METHOD: Uncapsulated joint models having 28 (A), 32 (B) and 36 (C) mm diameters were sealed with moulded preformed silicone labra. An increasing traction force was applied under water on the fixed joint. Using specially designed software, the exerted force and the dislocation distance were simultaneously and continuously recorded on a computer. The SPR of the examined joint models was calculated as the difference between the maximal exerted force and the weight of the ball-neck component. RESULTS: Statistical analyses showed that SPR had mean values of 58.12 +/- 2.23 N for the 28 mm joint model (n = 118; A), 75.66 +/- 2.75 N for the 32 mm model (n = 88; B) and 99.91 +/- 1.30 N for the 36 mm model (n = 82; C). CONCLUSION: The traction force required for dislocation agreed closely to the expected precalculated SPR values of 58.6 N (A), 76.4 N (B) and 96.7 N (C), which proves the joint stabilising effect of AP in the presence of the essential prerequisites (spherical ball articulating in a hemispherical socket, hermetically closed joint capsule and/or labrum, which contains a small amount of fluid and excludes air). The measured SPR was directly proportional to the square of the joint diameter. Indirectly, it was concluded that the dislocation work at rest is directly proportional to the joint diameter cubed. Consequently, the risk of dislocation after total hip arthroplasty (THA) can be reduced by applying bigger, size-adapted hip balls, whose diameter grows according to the outer diameter of the cup. The increasing range of motion is a favourable side-effect. With careful reconstruction of the capsule and insertion of an intracapsular drain, the risk of dislocation in the early postoperative period could be furtherly reduced. Theoretically, artificial labra could be a useful alternative to augment joint stability in THA with a high dislocation tendency instead of constrained liners.

[Painful enlargement of the 2nd toe due to an osteoid osteoma in the distal phalanx]. / Schmerzhafte Hypertrophie der zweiten Zehe infolge Osteoidosteom des Endgliedes.

The rare case of an osteoid osteoma in the distal phalanx of the 2nd toe resulting in painful enlargement and hypertrophy of the entire toe in a 12-year-old girl is discussed. The tumour was excised and the oversize of the toe was corrected by exarticulation of the distal phalanx. 18 months postoperatively the patient demonstrates normal function of her forefoot without complaints or signs of inflammation.

[Metastatic malignant choroidal melanoma: a case report about 18 years with palliative operative treatment]. / Metastasierendes malignes Aderhautmelanom: Einzelfalldarstellung eines protrahierten Verlaufs über 18 Jahre durch palliative operative Therapie.

Bone metastases are found in 29% of patients with metastatic malignant choroidal melanoma, which is associated with poor prognosis. However there are several reports about prolonged survival. The unusual case of a patient is described, who suffered from a melanoma with orbital invasion and survived more than 18 years. Metastases were found 12 years after initial therapy. Three palliative operations made a survival of further 7 years with high quality of life possible. Therefore moderately palliative operations are recommended in case of metastatic malignant choroidal melanoma.

[Webers experiments regarding the stabilising effect of atmospheric pressure on the hip joint - a historical and experimental retrospect]. / Die Weber'schen Versuche zur hüftstabilisierenden Wirkung des atmosphärischen Druckes - ein historischer und experimenteller Rückblick.

BACKGROUND: The stabilising effect of atmospheric pressure on the hip joint was first described by the brothers Eduard and Wilhelm Weber in 1836. Later in 1837, they conducted an experiment in which they examined a weight-bearing cadaveric hip joint in an evacuable container and could repeatedly demonstrate dislocation of the femur head due to the significant reduction of surrounding pressure and its repositioning by normalisation of the pressure. In our study we aimed to honour the contribution of the Weber brothers, to reflect on the historical argument about the hip stabilising effect of atmospheric pressure they initiated, to repeat the famous experiment they did in 1837 using advanced sensors and radiological equipment and to demonstrate the consequences of the effect on total hip arthroplasty. METHOD: A weight-bearing human cadaveric hip joint was placed in a radiolucent evacuable container, in which the pressure was reduced with a vacuum pump and normalised by opening a valve. Pressure and dislocation distance were measured continuously by sensors. The state of the hip joint was documented both by X-ray as well as by permanent fluoroscopy with video recording. RESULTS: Conforming to the experiments published in 1837 we demonstrated dislocation of the hip joint as a result of a significant reduction of pressure. Normalisation of the pressure caused joint reduction. The ability of the cadaveric hip to bear weight depended to a great extent on its quality. Reduction of the pressure harmed the cadaveric hip and reduced the number of possible experiments. CONCLUSION: The stabilising effect of atmospheric pressure on the hip joint is a fact, which was proved in 1836/37 by the Weber brothers, who conducted convincing experiments with human cadaveric hip joints. Nevertheless, the investigation into this relationship continues until today. We repeated and reproduced their experiment published in 1837 which irrefutably proved the stabilising effect of atmospheric pressure on the hip joint. The surgical application is of the utmost importance in the field of hip arthroplasty. Careful handling and reconstruction of the capsula, the use of size-adapted large hip balls as well as the intra-articular drainage provide the basis for maintaining the optimal mechanical environment and avoiding postoperative dislocation. Due to the variation in quality and anatomic characteristics of cadaveric hip specimens, we decided to use standardised model joints for further experiments.

[Operative treatment of an expansive enchondroma of the distal phalanx of the thumb]. / Operative Therapie beim expansiven Enchondrom der Daumenendphalanx.

Enchondroma is the second most common benign bone tumour and the most common tumour affecting the bones of the hand. In the hand, they are most frequently found in the proximal phalanges. The case presented here is that of an expansive enchondroma in the distal phalanx of the thumb, which is rare. By operative treatment (curettage, reduction plastic and cancellous bone allografting) we were able to correct the deformity of the distal phalanx and the thumbnail almost completely, as well as improving the stability and achieving a good cosmetic result.

[The stabilizing effect of atmospheric pressure (AP) on hip joint subject to traction force--an experimental study]. / Die stabilisierende Wirkung des atmosphärischen Druckes auf das Hüftgelenk bei Einwirkung einer Zugkraft--eine experimentelle Studie.

AIM: We aimed to prove the stabilising effect of atmospheric pressure (AP) on the hip joint experimentally. METHOD: In the experiment, model joints of 28 mm, 32 mm und 36 mm diameter were subjected to increasing traction force. The acting force and the resulting dislocation distance were measured both with the capsule hermetically sealed, as well as with the capsula open. RESULTS: For the hermetically sealed capsule we measured maximum resistances of 7.6 kp for the 28 mm joint, 10.4 kp for the 32 mm joint and 12.4 kp for the 36 mm joint. With the capsule open we found resistances from 0.4 kp to 1 kp. Our experimental results exceeded the predicted resistances of 6 kp, 7.8 kp and 9.9 kp. Increased amounts of synovial fluid reduced the stability. CONCLUSION: Our measurements confirm the continual stabilising effect of AP on the hip joint, which can be quantified as the resting potential of stability (RPS) or luxation work (LW). The RPS is calculated by multiplying the difference of AP and saturated vapour pressure of synovial fluid with the cross-sectional area of the femoral head. It represents the force, necessary for luxation of the joint against the resistance of AP. The RPS is proportional to the square of the joint diameter. The LW, calculated by multiplying RPS with the luxation distance, is proportional to the joint diameter cubed. That is why a small increase of joint diameter leads to a significant increase of stability, while the rate of the increase of range-of-motion decreases. To achieve stability of a total hip arthroplasty the size of the joint components should depend on the size of the resected femoral head. Also the hermetically sealed capsule should be reconstructed carefully.