A predominant Th1 polarization is present in synovial fluid of end-stage osteoarthritic knee joints: analysis of peripheral blood, synovial fluid and synovial membrane.

Thorough understanding of the complex pathophysiology of osteoarthritis (OA) is necessary in order to open new avenues for treatment. The aim of this study was to characterize the CD4+ T cell population and evaluate their activation and polarization status in OA joints. Fifty-five patients with end-stage knee OA (Kellgren-Lawrence grades III-IV) who underwent surgery for total knee arthroplasty (TKA) were enrolled into this study. Matched samples of synovial membrane (SM), synovial fluid (SF) and peripheral blood (PB) were analysed for CD3+ CD4+ CD8- T cell subsets [T helper type 1 (Th1), Th2, Th17, regulatory T cells] and activation status (CD25, CD69, CD45RO, CD45RA, CD62L) by flow cytometry. Subset-specific cytokines were analysed by cytometric bead array (CBA). SM and SF samples showed a distinct infiltration pattern of CD4+ T cells. In comparison to PB, a higher amount of joint-derived T cells was polarized into CD3+ CD4+ CD8- T cell subsets, with the most significant increase for proinflammatory Th1 cells in SF. CBA analysis revealed significantly increased immunomodulating cytokines [interferon (IFN)-γ, interleukin (IL)-2 and IL-10] in SF compared to PB. Whereas in PB only a small proportion of CD4+ T cells were activated, the majority of joint-derived CD4+ T cells can be characterized as activated effector memory cells (CD69+ CD45RO+ CD62L- ). End-stage OA knees are characterized by an increased CD4+ T cell polarization towards activated Th1 cells and cytokine secretion compared to PB. This local inflammation may contribute to disease aggravation and eventually perpetuate the disease process.

[Risk factors for the development of rotator cuff tears in individuals with paraplegia : A cross-sectional study]. / Risikofaktoren für Rotatorenmanschettenrupturen bei Paraplegikern : Eine Querschnittstudie.

QUESTION: Shoulder pain and rotator cuff tears are highly prevalent among wheelchair dependent individuals with paraplegia. The purpose of this study was to identify potential risk factors associated with the development of rotator cuff tears in this population. METHODS: A total of 217 wheelchair dependent individuals with paraplegia were included in this cross-sectional study (level of evidence III). The mean age of this population was 47.9 years and the mean duration of wheelchair dependence was 24.1 years. Each individual was asked to complete a questionnaire designed to identify risk factors for rotator cuff tears and underwent a standardized clinical examination with the documentation of the Constant-Murley shoulder outcome score and magnetic resonance imaging (MRI) of both shoulder joints. RESULTS: MRI analysis revealed at least one rotator cuff tear in 93 patients (43%). Multiple logistic regression analysis identified the following factors to be associated with the presence of rotator cuff tear: patient age, duration of spinal cord injury/wheelchair dependence, gender, and wheelchair athletic activity. Neither BMI nor the level of spinal cord injury was found to pose a risk factor in the population studied. With respect to patient age, the risk of developing a rotator cuff tear increased by 11% per annum. In terms of duration of spinal cord injury, the analysis revealed a 6% increased risk per year of wheelchair dependence (OR = 1.06). Females had a 2.6-fold higher risk of developing rotator cuff tears than males and wheelchair sport activity increased the risk 2.3-fold. DISCUSSION: There is a high prevalence of rotator cuff tears in wheel-chair dependent persons with paraplegia. Risk factors such as age, gender, duration of paraplegia, and wheel chair sport activity seem to play an important role in the development of rotator cuff tears.

[Results from the German shoulder- and elbow arthroplasty register (SEPR) : Anatomic or reverse shoulder arthroplasty in B2-glenoids?] / Ergebnisse des deutschen Schulter- und Ellenbogenprothesenregisters (SEPR) : Anatomische oder inverse Prothese bei B2-Glenoid?

BACKGROUND: Anatomic shoulder arthroplasty in osteoarthritis with biconcave glenoid wear results in decreased functional results and a higher rate of early glenoid loosening. AIM: The aim of the data analysis of the German shoulder arthroplasty register was to clarify whether reverse shoulder arthroplasty can provide better functional results and a lower complication rate than anatomic arthroplasty in osteoarthritis with biconcave glenoid wear. METHODS: The analysis included 1052 completely documented primary implanted arthroplasties with a minimum follow-up of 2 years. In 119 cases, a B2-type glenoid was present. Out of these cases, 86 were treated with an anatomic shoulder arthroplasty, and in 33 cases a reverse shoulder arthroplasty was implanted. The mean follow-up was 47.6 months. RESULTS: The Constant score with its subcategories, as well as the active range of movement improved significantly after anatomic and after reverse shoulder arthroplasty. DISCUSSION: We observed no difference in functional results between both types of arthroplasty; however, reverse arthroplasty showed a significant higher revision rate (21.2%) (3% glenoid loosening, 6% prosthetic instability) than anatomic shoulder arthroplasty (12.8%) (11.6% glenoid loosening, 1.2% prosthetic instability), whereas anatomic shoulder arthroplasty showed a higher rate of glenoid loosening. Functional and radiographic results of both types of arthroplasty are comparable with the results reported in the literature, although our analysis represents results from an implant registry (data pertaining to medical care quality).

The medium- and long-term outcome of total shoulder arthroplasty for primary glenohumeral osteoarthritis in middle-aged patients.

AIMS: Promising medium-term results from total shoulder arthroplasty (TSA) have been reported for the treatment of primary osteoarthritis in young and middle-aged patients. The aim of this study was to evaluate the long-term functional and radiological outcome of TSA in the middle-aged patient. PATIENTS AND METHODS: The data of all patients from the previous medium-term study were available. At a mean follow-up of 13 years (8 to 17), we reviewed 21 patients (12 men, nine women, 21 shoulders) with a mean age of 55 years (37 to 60). The Constant-Murley score (CS) with its subgroups and subjective satisfaction were measured. Radiological signs of implant loosening were analysed. RESULTS: Two shoulders (two patients) were revised and in two shoulders of two different patients, revision surgery was recommended. The mean CS increased from 23.3 (10 to 45) pre-operatively to 56.5 (26 to 81; p < 0.0001), but with a decrease in CS from 62.8 (38 to 93) to 56.5 (26 to 81) between medium- and long-term follow-up (p = 0.01). Without revision surgery, 18 patients (95%) rated their result as good or very good. The mean radiolucent line score for the glenoid components increased from 1.8 (0 to 6) to 8.2 (2 to 18) between medium- and long-term follow-up (p < 0.001). CONCLUSION: TSA in young and middle-aged patients leads to improvement in clinical function and a relatively high satisfaction rate. However, clinical or radiological glenoid loosening worsens in the long term. Further studies are needed to optimise the treatment options in this patient population. Cite this article: Bone Joint J 2017;99-B:939-43.

Return to sports and work after partial shoulder replacement surgery.

BACKGROUND: Shoulder hemiarthroplasty is a particularly attractive treatment option in young active patients, where revision surgery is an issue and a glenoid replacement might be necessary in the long run. These patients often ask about the possibility of returning to sport and work after surgery. OBJECTIVE: The purpose of this investigation was to analyze whether patients undergoing shoulder hemiarthroplasty (HSA) are able to successfully return to sports activities and work after surgery. MATERIALS AND METHODS: This study included 42 patients treated with HSA. Two subgroups were built: patients who had participated in sports less than 5 years prior to surgery (group A: n = 29, 69%) and those who had not done so (group B: n = 13, 31%). Evaluation was based on a questionnaire asking about types of sports, frequency of sports activity, and the time taken to return to sports and work, as well as about limitations in occupational life. RESULTS: Patients' mean age at the time of surgery was 56.3 ± 12.7 years in group A and 66.9 ± 13.8 years in group B. Mean follow-up was 5.5 years (range 2.5-12 years). In group A, 18 patients (62%) had participated in sports up to the time of surgery and 12 (41%) had returned to the same level of sports activity at final follow-up. The rate of return to preoperative sports activity was 67%. Swimming was one of the most favorable sports (92%). Of the cohort patients, 2 (5%) had to change their profession due to surgery. Most patients were retired at follow-up. CONCLUSION: Patients who were sportingly active prior to HSA were able to return to sports after surgery in 67% of cases. This study confirms that patients treated by hemiarthroplasty of the shoulder joint can return to sports and work, even at medium-term follow-up.

[Clinical or radiological diagnosis of impingement]. / Klinische oder radiologische Diagnose des Impingements.

CLINICAL/METHODICAL ISSUE: Shoulder impingement syndrome is a clinically common entity involving trapping of tendons or bursa with typical clinical findings. STANDARD RADIOLOGICAL METHODS: Important radiological procedures are ultrasound, magnetic resonance imaging (MRI) and MR arthrography. Projection radiography and computed tomography (CT) are ideal to identify bony changes and CT arthrography also serves as an alternative method in cases of contraindications for MRI. These modalities support the clinically suspected diagnosis of impingement syndrome and may identify its cause in primary diagnosis. In addition, effects of impingement are determined by imaging. Therapy decisions are based on a synopsis of radiological and clinical findings. PERFORMANCE: The sensitivity and specificity of these imaging modalities with regard to the diagnostics of a clinically evident impingement syndrome are given in this review article. PRACTICAL RECOMMENDATIONS: Orthopedic and trauma surgeons express the suspicion of an impingement syndrome based on patient history and physical examination and radiologists confirm structural changes and damage of intra-articular structures using dedicated imaging techniques.

Can reverse shoulder arthroplasty in post-traumatic revision surgery restore the ability to perform activities of daily living?

BACKGROUND: Failed shoulder arthroplasty and failed internal fixation in fractures of the proximal humerus can benefit from implantation of a reverse total shoulder arthroplasty (RSA). While there is some evidence that RSA can improve function regarding range of motion (ROM), pain, satisfaction, and strength, there is sparse data how this translates into activities of daily living (ADLs). A marker-based 3D video motion analysis system has recently been designed that can measure changes of ROM in dynamic movements in every plane. The hypothesis was that a gain of maximum ROM also translates into the ability to perform ADLs and into a significant increase of ROM in ADLs. MATERIALS AND METHODS: Six consecutive patients (5 women, 1 man; 2× failed arthroplasty, 4× failed open reduction and internal fixation) who received RSA were examined the day before and 1 year after shoulder replacement. A 3D motion analysis system using a novel upper extremity model measured active maximum values and ROM in four ADLs. RESULTS: Comparing the pre- to the 1-year postoperative status, RSA resulted in a significant increase in mean maximum values for active flexion (humerus to thorax) of 37° (S.D. ±23°), from 50 to 87° [P=0.005], and for active abduction averaging of 17° (S.D. ±13°), from 52 to 69° [P=0.027]. The extension decreased significantly by about 8° (S.D. ±16°), from a mean of 39 to 31° [P=0.009]. For active adduction and internal and external rotation, there were trends for improvements, but no significant changes. Only three additional tasks of the ADL (out of 13/24 preoperatively) could be performed after revision surgery. Comparing the preoperative to the postoperative ROM in the ADLs in flexion/extension, ROM improved significantly in one ("tying an apron") of four ADLs. There were no significant changes in the abduction/adduction and internal/external rotation in any ADLs. CONCLUSION: RSA in revision cases significantly improved maximum active flexion and abduction, but decreased extension in this series. However, the patients were only able to use this greater ROM to their benefit in one of four ADLs.

Unicompartmental and bicompartmental knee osteoarthritis show different patterns of mononuclear cell infiltration and cytokine release in the affected joints.

It is still controversial which cell types are responsible for synovial inflammation in osteoarthritic (OA) joints. The aim of this study was to quantify the mononuclear cell populations and their cytokines in patients with different knee OA subtypes. Synovial membrane (SM), synovial fluid (SF) and peripheral blood (PB) were harvested from patients with unicompartmental (UC) and bicompartmental (BC) knee OA. Frequencies of mononuclear cells were assessed by flow cytometry in PB and SM. Naive SF samples were analysed for a broad variety of cytokines by multiplex analysis. SM of both groups displayed a distinct mononuclear cell infiltration, with CD14(+) macrophages being the major cell population, followed by CD4(+) T cells and only small numbers of CD8(+) T, CD19(+) B and CD16(+) CD56(+) natural killer (NK) cells. Between the two groups, SM of BC OA showed significantly higher amounts of mononuclear cells (135·7 ± 180 versus 805 ± 675 cells/mg, P = 0·0009) and higher CD4(+) T cell presence (3·4 ± 4·6 versus 9·1 ± 7·5%, P = 0·0267). SF of BC OA displayed significantly higher concentrations for a number of proinflammatory cytokines [CXCL1, eotaxin, interferon (IFN)-γ, interleukin (IL)-7, IL-8, IL-9, IL-12]. UC and BC OA show significant differences in their synovial inflammatory pattern. Whereas in UC OA CD14(+) macrophages are the predominant cell population, BC OA has a higher inflammatory profile and seems to be driven by CD14(+) macrophages and CD4(+) T cells. Inclusion of clinical information into the analysis of cellular and molecular results is pivotal in understanding the pathophysiology of OA.

[Imaging of the elbow joint with focus MRI. Part 2: muscles, nerves and synovial membranes]. / Bildgebung des Ellenbogengelenks mit Fokus MRT. Teil 2: Muskeln, Nerven und Synovia.

This review article discusses the magnetic resonance imaging (MRI) features and pathological changes of muscles, nerves and the synovial lining of the elbow joint. Typical imaging findings are illustrated and discussed. In addition, the cross-sectional anatomy and anatomical variants, such as accessory muscles and plicae are discussed. Injuries of the muscles surrounding the elbow joint, as well as chronic irritation are particularly common in athletes. Morphological changes in MRI, for example tennis or golfer's elbow are typical and often groundbreaking. By adapting the examination sequences, imaging planes and slices, complete and incomplete tendon ruptures can be reliably diagnosed. Although the clinical and electrophysiological examinations form the basis for the diagnosis of peripheral neuropathies, MRI provides useful additional information about the precise localization due to its high resolution and good soft tissue contrast and helps to rule out differential diagnoses. Synovial diseases, such as inflammatory arthritis, proliferative diseases and also impinging plicae must be considered in the MRI diagnostics of the elbow joint.

[Imaging of the elbow joint with focused MRI. Part 1: examination techniques and sequences for bone and ligaments]. / Bildgebung des Ellenbogengelenks mit Fokus MRT. Teil 1: Untersuchungstechniken und -sequenzen, Knochen und Ligamente.

Imaging of the elbow joint places high demands on the quality of imaging due to the challenging anatomy and the sometimes subtle findings. For the diagnosis of periarticular soft tissues, ligamentous structures and in individual cases for fracture and tumor diagnosis, magnetic resonance imaging (MRI) is mostly groundbreaking and allows a reliable diagnosis in most cases. This review article discusses the complex imaging anatomy and anatomical variants of this joint and the most common osseous and ligamentous injuries of the elbow joint are presented. The typical MRI findings and indications are illustrated and discussed and possible pitfalls are pointed out. The various examination techniques and MRI sequences are also addressed.

The influence of bone marrow- and synovium-derived mesenchymal stromal cells from osteoarthritis patients on regulatory T cells in co-culture.

There is increasing evidence that inflammation in the synovium plays a major role in the progression of osteoarthritis (OA). However, the immunogenic properties of mesenchymal stromal cells (MSCs), which are considered to regulate immunity in various diseases, remain largely unknown in OA. The purpose of this study was to determine the influence of MSCs from OA patients on regulatory T cells (Tregs ) in an allogeneic co-culture model. Bone marrow (BM) and synovial membrane (SM) were harvested from hip joints of OA patients and co-cultured with lymphocytes enriched in CD4(+) CD25(+) CD127(-) regulatory T cells (Treg (+) LC) from healthy donors. Treg proportions and MSC markers were assessed by flow cytometry. Cytokine levels were assessed after 2 and 5 days of co-cultivation. Additionally, Treg (+) LC cultures were analysed in the presence of interleukin (IL)-6 and MSC-supernatant complemented medium. B-MSCs and S-MSCs were able to retain the Treg proportion compared to lymphocyte monocultures. T cell-MSC co-cultures showed a significant increase of IL-6 compared to MSC cultures. S-MSCs produced higher amounts of IL-6 compared to B-MSCs, both in single and T cell co-cultures. The effect of retaining the Treg percentage could be reproduced partially by IL-6 addition to the medium, but could only be observed fully when using MSC culture supernatants. Our data demonstrate that retaining the Treg phenotype in MSC-T cell co-cultures can be mediated by MSC derived from OA patients. IL-6 plays an important role in mediating these processes. To our knowledge, this study is the first describing the interaction of MSCs from OA patients and Tregs in an allogeneic co-culture model.

[Prostheses for fractures of the proximal humerus: presentation of current results of anatomical fracture shoulder prosthesis under consideration of alternative concepts]. / Prothetik bei proximalen Humerusfrakturen: Präsentation aktueller Ergebnisse der anatomischen Frakturschulterprothese unter Würdigung relevanter Alternativkonzepte.

BACKGROUND: The purpose of this present study was to review the functional and radiological results of patients with complex fractures of the proximal humerus who were treated with an anatomical shoulder prosthesis. PATIENTS AND METHODS: Between 1999 and 2005 a total of 61 patients were treated with an anatomical trauma prosthesis after an acute fracture. RESULTS: Thirty-eight patients (31 women and 7 men) with a mean age of 72 (range, 31-85) years could be followed-up. The absolute Constant score averaged 57.7 of 100 (range, 32-86) points by a mean of 86 (range, 60-129) months. Postoperative active elevation averaged 105 (range, 50-180)° and active abduction averaged 96 (50-180)°. Tuberosity resorption was found in 52% (20/38) at final follow-up. The outcome was significantly better in patients with healing of the tuberosities (p = 0.02). CONCLUSION: With the use of an anatomical trauma prosthesis the reduction of the pain level is excellent while the gain in function is only slight. The bony union of the tuberosities in an anatomical position is essential to achieve good results.

Humeral surface replacement for the sequelae of fractures of the proximal humerus.

Fractures of the proximal humerus can lead to malalignment of the humeral head, necrosis and post-traumatic osteoarthritis. In such cases surface replacement might be a promising option. A total of 28 shoulders with glenohumeral arthritis subsequent to a fracture underwent surface replacement arthroplasty of the humeral head in patients with a mean age of 60 years (35 to 83). On the basis of the inclination of the impacted head, post-traumatic arthritis was divided into three types: type 1, an impacted fracture of the head in an anatomical position (seven cases); type 2, a valgus impacted fracture (13 cases); type 3, a varus impacted fracture (eight cases). The outcome was measured by means of the Constant score. According to the Boileau classification of the sequelae of fractures of the proximal humerus, all 28 patients had a final result of intra-capsular category 1. The mean Constant score for the 28 shoulders increased from 23.2 points (2 to 45) pre-operatively to 55.1 points (20 to 89) at a mean of 31 months (24 to 66) post-operatively. Valgus impacted fractures had significantly better results (p < 0.039). Surface replacement arthroplasty can provide good results for patients with post-traumatic osteoarthritis of the shoulder. Their use avoids post-operative complications of the humeral shaft, such as peri-prosthetic fractures. Further surgery can be undertaken more easily as the bone stock is preserved.

Mid-term survivorship analysis of a shoulder replacement with a keeled glenoid and a modern cementing technique.

We have investigated the mid-term outcome of total shoulder replacement using a keeled cemented glenoid component and a modern cementing technique with regard to the causes of failure and loosening of the components. Between 1997 and 2003 we performed 96 total shoulder replacements on 88 patients, 24 men and 64 women with a mean age of 69.7 years (31 to 82). The minimum follow-up was five years and at the time of review 87 shoulders (77 patients) were examined at a mean follow-up of 89.1 months (60 to 127). Cumulative survival curves were generated with re-operations (accomplished and planned), survivorship of the proshesis, loosening of the glenoid (defined as tilt > 5 degrees or subsidence > 5 mm), the presence of radiolucent lines and a Constant score of < 30 as the endpoints. There were two re-operations not involving revision of the implants and the survival rate of the prosthesis was 100.0% for the follow-up period, with an absolute Constant score of > 30 as the endpoint the survival rate was 98%. Radiological glenoid loosening was 9% after five years, and 33% after nine years. There was an incidence of 8% of radiolucent lines in more than three of six zones in the immediate post-operative period, of 37.0% after the first year which increased to 87.0% after nine years. There was no correlation between the score of Boileau and the total Constant score at the latest follow-up, but there was correlation between glenoid loosening and pain (p = 0.001). We found that total shoulder replacement had an excellent mid-term survivorship and clinical outcome. The surgical and cementing techniques were related to the decrease in radiolucent lines around the glenoid compared with earlier studies. One concern, however, was the fact that radiolucent lines increased over time and there was a rate of glenoid loosening of 9% after five years and 33% after nine years. This suggests that the design of the glenoid component, and the implantation and cementing techniques may need further improvement.

Limb-salvage reconstruction with MUTARS hemipelvic endoprosthesis: a prospective multicenter study.

BACKGROUND: Limb-sparing surgery with hemipelvic megaprosthetic replacement is often limited by the high rate of associated complications. The aim of this evaluation was to assess clinical and oncological findings with respect to type, treatment and outcome of post-operative complications. METHODS: First results of 40 patients treated with individual MUTARS hemipelvic endoprostheses were evaluated in a prospective multicenter study. RESULTS: The mean follow-up period of the 27 male and 13 female patients was 24 months (range 1-61). The diagnosis was, in 29 cases, a primary bone or soft tissue sarcoma, in 11 patients, a metastasis. Clinical evaluation showed a mean Enneking score of 50% (range 10-70%). The oncological outcome revealed 25 patients (62.5%) alive with no evidence of disease. Seventeen of them had a primary tumour, eight a metastatic malignancy. Seven patients (17.5%) had died of their disease and eight (20%) were still alive but had developed a metastases and/or had had a recurrence of the primary tumour. The one- and two-year overall survival rate of the patients was 89% (+/- 0.10) and 81% (+/- 0.19), respectively. Post-operative complications occurred in 75% of the patients, predominantly wound-related disorders. The rate of implant revision was 22.5% with three septic and six aseptic cases of implant loosening. The estimated three-year-survival rate of the implant was 61.4% [CI95%: 0.36;0.87]. CONCLUSIONS: Periacetabular endoprosthetic replacement showed an acceptable functional and oncological outcome but had a high complication rate owing, predominantly, to infection. The indication for hemipelvic prosthesis in patients with a metastatic disease must be considered seriously.

Compliance with continuous passive movement is low after surgical treatment of idiopathic club foot in infants: a prospective, double-blinded clinical study.

Treatment by continuous passive movement at home is an alternative to immobilisation in a cast after surgery for club foot. Compliance with the recommended treatment, of at least four hours daily, is unknown. The duration of treatment was measured in 24 of 27 consecutive children with a mean age of 24 months (5 to 75) following posteromedial release for idiopathic club foot. Only 21% (5) of the children used the continuous passive movement machine as recommended. The mean duration of treatment at home each day was 126 minutes (11 to 496). The mean range of movement for plantar flexion improved from 15.2 degrees (10.0 degrees to 20.6 degrees ) to 18.7 degrees (10.0 degrees to 33.0 degrees ) and for dorsiflexion from 12.3 degrees (7.4 degrees to 19.4 degrees ) to 18.9 degrees (10.0 degrees to 24.1 degrees ) (both, p = 0.0001) when the first third of therapy was compared with the last third. A low level of patient compliance must be considered when the outcome after treatment at home is interpreted.

Preoperative elevation of serum C--reactive protein is predictive for prognosis in myeloma bone disease after surgery.

We investigated whether preoperative levels of serum C-reactive protein (CRP) and its correlation with tumour clinicopathological findings adds prognostic information beyond the time of diagnosis in patients with myeloma bone disease (MM) to facilitate the surgical decision-making process. Six hundred and fifty-eight myeloma patients were evaluated retrospectively for surgery. Clinicopathological variables of patients who underwent surgery (n=71) were compared between patients with preoperative CRP>or=6 mg l-1 and those with CRP<6 mg l-1. Univariate and multivariate analyses were performed to identify prognostic factors after surgery. Patients with an increase of CRP prior to surgery showed inferior survival compared to patients with normal levels. Patients with normal CRP levels at diagnosis but elevations prior to surgery do seem to have a similar unfavourable overall survival (OS) than patients with an increase both, at diagnosis and at surgery. Conversely, patients with normal CRP levels prior to surgery still have the best OS, irrespective of their basic values. Multivariate analysis revealed preoperative CRP levels above 6 mg l-1 Lactate dehydrogenase (LDH) above normal, and osteolyses in long weight bearing bones as independent predictors of survival. These findings suggest that in patients with MM serum levels of CRP increase during disease activity and might be significantly correlated with specific disease characteristics including adverse prognostic features such as osteolyses in long weight bearing bones. Thus, preoperative elevated CRP serum levels might be considered as independent predictor of prognosis and could provide additional prognostic information for the risk stratification before surgical treatment in patients with myeloma bone disease.

Mechanical performance of cylindrical and dual core pedicle screws in calf and human vertebrae.

INTRODUCTION: Failure of pedicle screws by loosening and back out remains a significant clinical problem. Pedicle screw fixation is determined by bone mineral density, pedicle morphology and screw design. The objective of this study was to compare the holding strength of newly developed dual core pedicle screws having a cylindrical design in terms of outer diameter and two cylindrical inner core regions connected by a conical transition with conventional cylindrical pedicle screws. MATERIALS AND METHODS: Fifty bovine lumbar vertebrae and 40 human lumbar vertebrae were used. Five different screws were tested in nine experimental "settings" and ten specimens each. The screws were tested for cranial displacement and pullout strength before and after 5,000 cycles of cranio-caudal loading. The tests included a setting with fully inserted and 4 mm backed out screws. For statistical analysis the incomplete balanced block design was used. RESULTS: Cyclic loading led to a decrease of pullout force between 24 and 31% and a 9% increase of displacement. The cylindrical screw designs were affected more than the dual core designs. The pullout force of cylindrical screws was smaller than of dual core screws. Even in a backed out condition dual core screws showed a significantly smaller displacement than cylindrical screws. CONCLUSION: Pedicle screws with the dual core design provide good anchorage in the vertebra.

Transarterial embolization of primary and secondary tumors of the skeletal system.

Percutaneous transcatheteral embolizations of primary and secondary bone tumors are important minimal invasive angiographic interventions of the skeletal system. In most of the cases embolization is performed for preoperative devascularization or as a palliative measure to treat tumor-associated pain or other tumor bulk symptoms. The transarterial embolization of primary and secondary tumors of the skeletal system has been developed to a safe and very effective method. Indications, techniques, results and complications of this minimal invasive interventional therapy for treatment of primary and secondary bone tumors are described and discussed and compared with the newer literature and our own results.