Reliability of three different visual acuity testing procedures in school children

AIM

To evaluate the usability and reliability of three different visual acuity (VA) testing procedures using Landolt C's in 8 positions with a semi-automated computer program in school children.

METHODS

100 school children (median 7 years, 59 boys and 41 girls) were included; only the better eye was tested. We used the semi-automated computer program CORVIS.VT in a forced choice method. Three different test strategies were employed, each two times: A) DIN, B) Standard-Staircase and C) Best-PEST procedure with sequences A, B, C or A, C, B.

RESULTS

Average testing time was 100 s +/- 45 (DIN), 59 s +/- 36 (Staircase) and 77 s +/- 25 (Best-PEST). The mean VA estimated with DIN was equivalent to that with the Best-PEST procedure. However, the mean VA with Standard-Staircase was one line less. In DIN, 76% of the retest scores were within 0.1 logMAR unit of the initial test score (Staircase: 72%, Best-PEST 73%). The 95% confidence interval of test-retest reliability was calculated to be -0.05 +/- 0.24 logMAR in DIN, +0.02 +/- 0.32 logMAR in Staircase, and 0.00 +/- 0.29 logMAR in Best-PEST.

CONCLUSION

A high percentage of children aged 6 to 9 years (98%) can be tested with Landolt C's (8 positions). We found a decreasing test-retest reliability starting from DIN via Best-PEST to Staircase in this configuration.

Renal cell carcinoma with tumor thrombus extension into the vena cava: prospective long-term followup

PURPOSE

We prospectively evaluated long-term survival in patients with renal cell carcinoma extending to the inferior vena cava.

MATERIALS AND METHODS

From 1993 and thereafter we followed 86 men and 48 women with a median age of 64 years (range 28 to 86) with renal cell carcinoma and tumor thrombus involvement of the inferior vena cava. Cancer specific survival was analyzed based on clinical therapy, tumor extent, thrombus level and grading.

RESULTS

Median followup was 16.4 months (range 0 to 178.9). At the time of this report 97 cancer specific deaths had occurred. Of the 134 patients 111 underwent radical nephrectomy, cavotomy and thrombus extraction, of whom 30 had distant metastases at surgery, and 23 were treated with embolization and immunotherapy. These nonsurgical patients who refused surgery had a high tumor load or a low Karnofsky performance status that may have affected survival. They died at a median of 6.9 months (range 0.1 to 23.6). Patients treated surgically, including those with metastases, had a significantly higher median survival of 19.8 months (range 0 to 178.9). Surgical patients with localized tumor (N0M0) had significantly higher median survival than those with metastatic (NxM1) disease (51.7 months, range 0 to 178.9 vs 6.9, range 0.6 to 149.7). Surgical patients with metastatic disease who underwent interferon and interleukin based immunotherapy had significantly higher median survival than those who did not (13.5 months, range 2.5 to 149.7 vs 5.1, range 0.6 to 24.0). On multivariate analysis localized tumor stage (N0M0) vs advanced tumor stage (N+M0 and NxM1), Fuhrman grade groups 1 and 2 vs 3 and 4, and tumor thrombus levels I and II vs III and IV were independent prognostic factors.

CONCLUSIONS

Currently radical surgery represents the only chance of long-term survival for patients with renal cell carcinoma and tumor thrombus extension in the inferior vena cava. Median cancer specific survival is significantly higher with localized tumor. However, even with metastatic disease radical surgery can prolong survival, especially when immunotherapy is added. Fuhrman grade and tumor thrombus level are also prognostic factors.

[The cemented MS-30 stem. A multi-surgeon series of 333 consecutive cases]

INTRODUCTION

So far there is only one peer-reviewed long-term publication from the inventors' clinic for the MS-30 stem.

MATERIAL AND METHODS

In a retrospective study we followed the first 333 consecutive MS-30 stems. All patients with 5- to 11-year follow-up were clinically and radiographically evaluated. At the time of implantation the criteria of modern cementing techniques were not implemented. Clinical evaluation was done using the scores of Harris and Merle d'Aubigné and Postel. Radiographic evaluation included quality of the cement mantle (true lateral radiographs taken under fluoroscopy), stem subsidence, loosening signs, and the risk for pending failure.

RESULTS

At follow-up 12 hips had undergone femoral revision: 3 for aseptic loosening, 6 for infection, 1 for periprosthetic fracture, and 2 for recurrent dislocation. The overall survival for all reasons at 10 years was 96.1%; survival with aseptic loosening as an end point was 99.0%. The median Harris Hip Score at follow-up was 80 (26-100) points. Radiological evaluation revealed a thin cement mantle (<2 mm) in approximately 2/3, predominantly on the lateral views (Gruen zones 8/9). One-third of all reviewed prostheses were considered at risk for pending failure, which strongly correlated with the initial quality of the cement mantle.

CONCLUSION

Midterm results with the MS-30 stem are encouraging and an even better long-term outcome can be expected with a better cement technique.

Interstitial fibrosis in the heart: differences in extracellular matrix proteins and matrix metalloproteinases in end-stage dilated, ischaemic and valvular cardiomyopathy

AIMS

To investigate whether or not there are differences in the distribution of extracellular matrix (ECM) proteins and matrix metalloproteinases (MMPs) in end-stage heart failure underlying different cardiomyopathies.

METHODS AND RESULTS

Thirty-nine explanted human hearts were investigated: 15 with dilated cardiomyopathy (DCM), 17 with ischaemic cardiomyopathy (ICM) and seven with valvular cardiomyopathy (VCM). Transmural samples from four different sites were investigated. Frozen sections were processed for immunohistochemistry for collagens type I, III, IV, laminin and fibronectin, as well as MMP-1, -2 and -9. Volume densities were determined. All ECM components were expressed more frequently in DCM than in ICM. Comparing ICM with VCM, all proteins were found more frequently in VCM than in ICM except for type III collagen, which was significantly more frequent in ICM. Comparing DCM and VCM, VCM showed significantly higher volume densities for type III collagen and laminin. MMPs showed only slight variations between the cardiomyopathies.

CONCLUSION

The distribution of ECM proteins differs between DCM, ICM and VCM, which suggests that they can be morphologically discriminated by interstitial fibrosis, especially by their expression of matrix proteins.

Cardiac surgery in renal transplant recipients: experience from Washington Hospital Center

BACKGROUND

The number of renal transplant survivors requiring surgical treatment for cardiovascular diseases is increasing. A retrospective study was conducted to determine the outcomes of renal transplant recipients undergoing cardiac surgery.

METHODS

Fifty-seven renal transplant recipients whose cardiac surgery was performed between 1987 and 2004, and whose allograft was functioning at the time of cardiac surgery, were identified. We analyzed postoperative mortality and morbidity as well as late mortality.

RESULTS

Among 57 patients, 70.2% had hypertension, 54.4% diabetes, and 28.1% poor left ventricular function (ejection fraction < 0.35). Preoperative renal insufficiency (serum creatinine level > or = 3 mg/dL) was noted in 12.3% of the patients. Coronary artery disease was the dominant indication for the surgery. The median interval from renal transplant to cardiac surgery was 60 months. In-hospital mortality was 5.3%. All deaths were cardiac-related. Infectious complications occurred in 17.5% of the patients. Acute allograft failure requiring hemodialysis occurred in 28.6% of the patients with preoperative renal insufficiency, more frequent than those without preoperative renal insufficiency. Multivariable analysis identified preoperative renal insufficiency, mitral valve disease, and left ventricular dysfunction as independent predictors of in-hospital major adverse events (including death, infection, and renal failure). The 3-year survival was 71% after a median follow-up of 34 months.

CONCLUSIONS

Infection control and renal protection should be stressed to ensure the safety of cardiac surgery in this patient group, while preoperative renal insufficiency, mitral valve disease, and left ventricular dysfunction are associated with early adverse outcomes. In the renal transplant recipients undergoing an isolated CABG, avoidance of cardiopulmonary bypass and use of arterial grafts might lead to better outcomes.

Molecular and biochemical investigations in fumarase deficiency

Fumarase (FH) deficiency is a rare autosomal recessive disease of the Krebs cycle causing severe neurological impairment in early childhood, characterized by encephalopathy with seizures and muscular hypotonia. Only a handful of patients with various recessive mutations in the FH gene have been described so far. Interestingly, autosomal dominant mutations in the same gene are associated with hereditary leiomyomatosis and renal cell cancer (HLRCC). We investigated a boy with developmental and growth delay, microcephaly, and muscular hypotonia recognized at the age of 3 months. No leiomyomatosis or renal cancer is known in the parents. Investigation of the patient's urine revealed massive fumarate excretion. FH activity was severely reduced in muscle and fibroblasts. Respirometric investigation of fibroblasts showed only modest changes indicating that fumarate mediated inhibition of enzymatic pathways other than oxidative phosphorylation might be more relevant in pathophysiology of FH deficiency. Molecular analysis revealed a known 435insK mutation on the paternal allele and a novel H275L mutation due to an A to T transversion of nucleotide 824 on the maternal allele. This mutation affects the same codon as a C to T transition of nucleotide 823, resulting in a H275Y mutation that was found in two families with HLRCC.

[Stüve-Wiedemann syndrome in two siblings: focusing on a male patient with the longest actual survival rate]

BACKGROUND

We report on two siblings with Stüve-Wiedemann syndrome (SWS). The older patient, a 16-year-old boy, is -- as to our knowledge -- the longest-term survivor of this syndrome worldwide. The younger sister with the same clinical and radiographic findings died at the age of 10 months.

DEFINITION

Characteristic clinical symptoms are: muscular hypotonia, camptodactyly; respiratory insufficiency, swallowing difficulties; reduced sweating with heat intolerance, episodes of hyperthermia. Typical radiographic findings are: progressive bone bowing, unusual bone fractures, abnormal trabecular pattern, middle face hypoplasia.

GENETICS

The SWS is identical with the Schwartz-Jampel syndrome (SJS) type 2, which is gene-located on chromosome 1. So far further genetic details of the SWS can be expected in the near future. The genetic transmission is autosomal recessive. In inbred high risk populations the occurrence of the SWS is increased.

THERAPY

For the present only symptomatic therapy is available: extended intensive care during infancy, supportive pediatric orthopedics later on.

Mueller reinforcement rings in acetabular revision: outcome in 164 hips followed for 2-17 years

BACKGROUND

In revision hip arthroplasty, cages are commonly used for acetabular reconstruction in cases with loss of bone stock. It is important to follow this patient group closely, in order to better understand failure mechanisms and the chance of long-term success.

PATIENTS AND METHODS

We followed our first 164 acetabular revisions with the Mueller reinforcement ring (ARR) in 164 patients, with an average follow-up period of 6 (2-17) years. Mean age at surgery was 69 (29-92) years. 39 patients died (39 hips) during follow-up, but only 3 patients (3 hips) were lost to follow-up.

RESULTS

In the observation period, 13 of the hips had to undergo acetabular re-revision for aseptic and septic loosening. Overall survival at 5 years was 95% (CI: 89%-98%) and 90% (CI: 76%-95%) at 8 years using acetabular re-revision or implant removal for all reasons as endpoint. In addition, mechanical and clinical failure was seen in 2 cases. The mean Harris hip score was 70 points, whilst the Merle d'Aubigné score averaged 7 points. Radiolucent lines according to DeLee and Charnley were observed twice in zone I, 6 times in zone II and 14 times in zone III.

INTERPRETATION

We found that mid- to long-term survival of the ARR is acceptable. However, failure of the implant due to allograft collapse/resorption or deep infection, and also poor clinical outcome, remain major concerns in acetabular revision arthroplasty. This should be recognized when advising patients.

Modelling the natural history of geographic atrophy in patients with age-related macular degeneration

PURPOSE

To model the natural course of geographic atrophy (GA) in patients with age-related macular degeneration (AMD).

METHODS

Data on the natural course of GA were collected in the multi-center, longitudinal, prospective observational FAM study. The size of GA was measured by autofluorescence scanning laser ophthalmoscopy. The natural course of GA is modelled by two different mixed effect models (MEM). Both models are compared with respect to the correctness of the model assumptions, goodness of fit, and predictive behavior.

RESULTS

The linear model results in better prediction, the non-linear model is more in agreement with the model assumptions. The non-linear model fits the data for small and large areas of GA better, while the linear model seems to be more adequate for the medial areas. More data will be needed to study the interplay of both models in more detail.

CONCLUSIONS

The natural course of GA varies extremely between individuals. However, reliable factors for the explanation of this variability have so far not been established. MEM are useful for describing "inter-individual" as well as "intra-individual" influences without the need for precise knowledge of the influencing factors. Using MEM to evaluate data on the natural history of GA allows one to derive parameter estimates, which could be used to design interventional trials for modes of therapy with a potential to reduce or stop the progression of GA in patients with AMD.

The belly-off sign: a new clinical diagnostic sign for subscapularis lesions

PURPOSE

We describe a new clinical sign for subscapularis lesions that we call the belly-off sign and compare its diagnostic value with standard subscapularis tests (the lift-off test, internal rotation lag sign, and belly-press test/Napoleon sign) in cases of different types of subscapularis lesions. The belly-off sign represents the inability of the patient to maintain the palm of the hand attached to the abdomen with the arm passively brought into flexion and internal rotation.

TYPE OF STUDY

Case series.

METHODS

This descriptive and explorative study included 60 patients (mean age, 55.3 years) with clinical, surgical, and/or magnetic resonance imaging-confirmed evidence of isolated or combined lesions of the subscapularis musculotendinous unit. In all patients, a complete physical shoulder examination was performed and the results were compared with the intraoperative and magnetic resonance imaging findings.

RESULTS

The belly-off sign appeared to be more reliable than any other diagnostic test or sign in detecting isolated partial tears of the subscapularis tendon (group I), combined partial subscapularis and complete supraspinatus tendon tears (group II), and postoperative subscapularis insufficiency with mild atrophy of the upper aspect of the subscapularis muscle (group VII). In cases of complete/near complete subscapularis tears with or without supraspinatus and infraspinatus tendon tears (groups IV, V, and VI), the belly-off sign appeared to be as reliable as the belly-press test, internal rotation lag sign, and lift-off test. For assessing partial subscapularis tendon tears and insufficient external rotators (group III), the belly-off sign was less reliable than any other diagnostic test or sign.

CONCLUSIONS

The belly-off sign represents a promising new clinical diagnostic sign for subscapularis lesions. In particular, subtle lesions of the upper subscapularis tendon and postoperative subscapularis insufficiencies can be detected by the belly-off sign in cases of intact external rotators. In cases of an advanced lack of external rotators, the belly-off sign becomes negative and loses its diagnostic value. We therefore conclude that the belly-off sign is attributable to an unbalanced transverse force couple with overwhelming of the external rotators of the shoulder.

LEVEL OF EVIDENCE

Level IV, case series with no, or historical, control group.

Extracellular matrix proteins and matrix metalloproteinases differ between various right and left ventricular sites in end-stage cardiomyopathies

This study was undertaken to investigate whether there might be differences in the distribution of extracellular matrix (ECM) proteins and matrix metalloproteinases (MMPs), depending on their specific sites within the heart. We investigated 33 explanted human hearts, 15 with dilated cardiomyopathy (DCM) and 18 with ischemic cardiomyopathy (ICM). Transmural samples from the right ventricle, the interventricular septum and the left ventricle, either from near the apex or from near the base were taken from every heart. Frozen sections were processed for connective tissue staining and immunohistochemistry for collagens type I, III, IV, laminin and fibronectin, as well as MMP-1, -2 and -9. Volume densities of laminin in ICM as well as of fibronectin and collagen types I and IV in DCM showed significant differences between right and left ventricular sites. The volume densities of matrix proteins usually did not reveal significant differences among the three left ventricular sites tested in both DCM and ICM. MMPs partly showed differences between the right and the left ventricular myocardium. These results suggest that the distributions of ECM proteins and MMPs differ between the two ventricles in both end-stage DCM and ICM. This gives rise to the hypothesis that a specific pattern of ECM degradation exists in the right and left ventricular myocardium.

External beam radiotherapy fails to prevent restenosis after iliac or femoropopliteal percutaneous transluminal angioplasty: results of a prospective randomized double-blind study

PURPOSE

Early restenosis is one of the major complications after successful percutaneous transluminal angioplasty (PTA), in main, as well as peripheral, arteries. The effectiveness of hypofractionated external beam radiotherapy (EBRT) as a prophylaxis for restenosis was examined in a prospective, randomized, double-blind, clinical trial.

METHODS AND MATERIALS

Forty-eight patients underwent sham RT and 47 were treated with daily RT in 3-Gy fractions, to a total dose of 21 Gy. The follow-up lasted for 12 months, and the examinations included pressure measurements and calculations of the ankle-brachial index or duplex sonography ("peak velocity ratio"). If restenosis was suspected, additional angiography was performed.

RESULTS

No statistically significant difference was found between the treatment groups: sham RT 16 failures (33.3%) and EBRT group 21 failures (45.7%; p = 0.292). EBRT also showed no substantial effects on subgroups classified by the specific length of the lesion or in diabetic patients.

CONCLUSION

External beam radiotherapy does not prevent restenosis. A reduction in the failure rate >8% using fractionated EBRT with doses aimed at keloid prevention can be ruled out with a probability of 97.5%. Endovascular brachytherapy remains the preferred therapeutic method for achieving restenosis prophylaxis through RT.

Effect of psychotherapy and relaxation on the psychosocial and somatic course of Crohn's disease: main results of the German Prospective Multicenter Psychotherapy Treatment study on Crohn's Disease

OBJECTIVE

Few studies have been published on the influence of psychotherapy on the physical and psychosocial course of Crohn's disease (CD).

METHODS

The present study, a prospective, randomized multicenter investigation conducted with 108 of 488 consecutive CD patients, was designed to investigate the influence of short-term psychodynamic therapy and relaxation in addition to a standardized glucocorticoid therapy on the somatic course of the disease as well as on patient psychosocial status. Based on the same standardized somatic treatment, the psychotherapy and control groups were compared after a 1-year treatment period and a follow-up of another year with regard to somatic course and psychosocial situation.

RESULTS

A total of 81 (75%) of 108 randomized patients completed the psychosocial follow-up. The comparison between the therapy groups after 1 year showed no significant differences in the four main target criteria of psychosocial status (depression, anxiety, psychosocial-communicative status and health-related quality of life). The mean Beck's Depression Inventory (BDI) score at admission was 12.3 in the psychotherapy group and 8.7 in the control group. At the 1-year follow-up, the scores for depression have been 7.8 (psychotherapy group) and 7.8 (control group). In the 2-year follow-up, 84 patients were classified into four groups on the basis of somatic course; 23% of the control group and 30% of the psychotherapy group showed episode-free courses, 29% and 17% respectively underwent surgery due to failure of immunosuppressive or medical therapy, and a further subranking showed no significant differences between the two groups (P=.125). At the 1-year follow-up, the scores for depression of patients with an active episode respective remission were 14.6 vs. 5.8. From the patient's point of view, at the end of the 2-year follow-up, the overall subjective evaluation of the effectiveness of psychotherapy was positive.

CONCLUSION

The patients included showed no psychosocial disturbances of clinical relevance. Although a tendency toward fewer surgical interventions, fewer relapses and reduction of depression was noted, the analysis was unable to demonstrate any benefit from psychosocial intervention on hypothesized parameters of psychosocial status and somatic course. Further studies should be performed to identify patient subgroups that may benefit from psychosocial intervention.

Anterosuperior impingement of the shoulder as a result of pulley lesions: a prospective arthroscopic study

Lesions of the biceps pulley and the rotator cuff have been reported to be associated with an internal anterosuperior impingement (ASI) of the shoulder. The purpose of this study was to determine the factors influencing the development of an ASI. Eighty-nine patients with an arthroscopically diagnosed pulley lesion were prospectively included in this study. Four patterns of intraarticular lesions could be identified. Twenty-six patients (group 1) showed an isolated lesion of the superior glenohumeral ligament (SGHL). In 21 patients (group 2) an SGHL lesion and a partial articular-side supraspinatus tendon tear were found. Twenty-two patients (group 3) had an SGHL lesion and a deep surface tear of the subscapularis tendon, and in twenty patients (group 4) a lesion of the SGHL combined with a partial articular-side supraspinatus and subscapularis tendon tear was diagnosed. Of the patients, 80 (89.9%) showed involvement of the long head of the biceps tendon including synovitis, subluxation, dislocation, and partial or complete tearing. In 43.8% of all patients, ASI was observed. Whereas ASI was seen in 26.6% and 19.1% of patients in groups 1 and 2, respectively, 59.1% of patients in group 3 and 75% of patients in group 4 were found to have an ASI. ASI was significantly more often seen in patients with additional partial articular-side subscapularis tendon tears (P <.0001). In patients with acromioclavicular (AC) arthritis, ASI (62.5%) was more frequently observed than in patients without AC arthritis (P =.0309). In the multivariate analysis the stepwise selection procedure revealed only AC arthritis and the deep surface tear of the subscapularis (groups 3 and 4) to be significant influencing factors for an ASI. Our findings indicate that a progressive lesion of the pulley system, including partial tears of the subscapularis and supraspinatus tendons, contributes significantly to the development of an ASI. A pulley lesion leads to instability of the long head of the biceps tendon, causing increased passive anterior translation and upward migration of the humeral head, resulting in an ASI. In addition, a partial articular-side subscapularis and supraspinatus tendon tear reinforces the ASI.

Die Reproduzierbarkeit des veno-arteriellen FlowIndex für die quantitative Erfassung des hämodynamischen Schweregrads von venösen Erkrankungen

Background: The ratio of volume flow in the common femoral vein and artery denoted as venous-arterial Flowindex (VAFI) is significantly increased in venous insufficiency according the clinical grade of the disease. This study was done to investigate the reliability and reproducibility of VAFI as quantitative pattern. Patients and methods: In 43 patients with varicose veins C4–6 EPAS,D,PPR (PVV), 40 with postthrombotic syndrome C4–6 ESAS,D,PPR,O (PTS) and 48 healthy volunteers volume flow in the common femoral vein (VFV) and artery (VFA) were measured by duplex. Division of VFV by VFA calculated VAFI. VAFI-measurement was repeated 5 times at an interval of ten minutes in 63 subjects (23 PVV, 20 PTS, 20 healthy) and it was performed at three different days in 68 subjects (20 PVV, 20 PTS, 28 healthy). Results: Mean VAFI ± standard deviation was 1.39 ± 0.26 in PVV, 1.42 ± 0.26 in PTS and 0.93 ± 0.13 in healthy veins (p < 0.001). VAFI remained stable and significantly increased (p < 0.001) in PVV and PTS compared to healthy veins during 40 minutes and also within three different days. Conclusion: The venous-arterial flowindex VAFI is a reproducible pattern of the hemodynamic severity in venous insufficiency.

Pattern of periprosthetic bone remodeling around stable uncemented tapered hip stems: a prospective 84-month follow-up study and a median 156-month cross-sectional study with DXA

Bone resorption in the proximal femur is commonly seen after total hip arthroplasty (THA). With dual energy X-ray absorptiometry (DXA), the amount of bone mass (BMD) after implantation of a total hip stem can be precisely determined. However, prospective evaluation of the change of bone mass around the stem is only available for selected stems and short-term follow-up (up to 36 months). We analyzed BMD in patients who had undergone uncemented THA by DXA. Only patients with good clinical outcome (Merle d' Aubigné score > 12) were included to obtain normative data for regular bone response. Two separate studies were performed: a prospective longitudinal study over 84 months with baseline values acquired within the first postoperative week (group A) (n = 26 patients) and a separate cross-sectional study, median follow-up 156 (124-178) months (group B) (n = 35 patients). Regions of interest were defined according to Gruen (ROI 1-7) and as net average ROI (net avg) for the periprosthetic femoral bone. After the initial remodeling process (12 months), BMD was compared to the 84-month (longitudinal) and the 156-month (cross-sectional) follow-up values to determine long-term periprosthetic changes of bone mineral density. The longitudinal study (group A), after the initial bone remodeling, showed no relevant further bone loss for women and men with BMD values 1.19 +/- 0.15 and 1.40 +/- 0.19, respectively, 12 months (women 89.8%, men 93.6%), and 1.19 +/- 0.13 and 1.36 +/- 0.18, respectively, after 84 months (women 90.0%, men 91.3%) (P = 0.98, P = 0.08,) respectively. The distribution of the BMD around the stem changed during the first 12 months. The ROIs around the proximal stem (ROI 1 and 7) showed the lowest absolute values at the 12-month follow-up and BMD in ROI 7 decreased most during the further follow-up until 84 months. The cross-sectional study (group B) showed no significant difference in BMD (net avg) values at a median of 156 months follow-up compared to the 12-month values (group A) (women: P = 0.77, men: P = 0.44). Initial BMD, implant diameter, and body mass index did not influence BMD loss (net avg) in this study, whereas age showed a weak correlation with BMD loss. The results show that after the initial remodeling process, no relevant further bone loss (net avg) occurs up to 84 months postsurgery, and values after a median of 156 months are similar. Normative long-term changes in the periprosthetic bone can be demonstrated in defined ROIs after implantation of a tapered corundum-blasted titanium stem with a good clinical result.

Robotic bone preparation does not increase cement penetration into the proximal femur: a matched-pair cadaver study comparing hand-broaching versus robotic bone preparation

In a cadaver study, we prepared 20 matched pairs of human femora using chipped-tooth broaches and robotic milling with the same geometry. For robotic bone preparation the CASPAR robotic system with a rotating milling head was used. Cancellous bone was irrigated with 1 liter of pulsed lavage and the specimens were embedded in specially-designed pots. After vacuum mixing, bone cement was introduced in a retrograde manner and subjected to a standard pressure protocol with a constant force of 3,000 N. Radiographs were taken and horizontal sections were obtained at predefined levels, using a diamond saw. Microradiographs of the bone slices were taken, digitized and analyzed to assess cement penetration into cancellous bone. No femoral fractures or fissures occurred with either preparation technique. The microradiographic evaluation showed no morphometric differences between chipped-tooth broaches and robotic milling as regards cement penetration into cancellous bone. Therefore, in the presence of pulsed lavage, we conclude that robotic bone preparation does not increase cement penetration into cancellous bone of the proximal end of the femur.

In vitro performance of intramedullary cement restrictors in total hip arthroplasty

Contemporary cementing techniques in total hip arthroplasty include the use of a cement restrictor to occlude the intramedullary canal. As there are many different designs currently available it was the aim of our study to compare the stability of eight different systems. We investigated the displacement and the ability to occlude the femur of these cement restrictors during standardised cementing of artificial and fresh frozen femora. The maximal intramedullary pressures and the displacement of the plugs were continuously recorded and statistically evaluated. The results revealed significant differences between the tested cement restrictors. The expandable REX Cement Stop and the Exeter Plug achieved the highest stability and the least cement leakage. The more rigid designs (Palacos Plug, BUCK, Universal) in contrast showed inferior performance. Our biomechanical study emphasises the importance of cement restrictor selection, which can have a crucial influence on the fixation of a cemented total hip replacement.

Composite grafts in the treatment of osteosarcoma of the proximal humerus

Treatment of osteosarcoma (OSA) of the proximal humerus poses many difficulties and challenges to the treating team. Between 1993 and 2000, we treated 11 patients (three women, eight men; age range, 17-74 years) suffering from OSA of the proximal humerus by 'composite': massive allografts and long humeral prosthesis. At presentation, 10 patients were at stage 2-B and one at stage 3-B of OSA. One patient presented with a pathologic fracture. All patients except patient No. 6, received preoperative chemotherapy followed by limb salvage surgery and postoperative chemotherapy.Surgical margins were graded as wide in all patients. Postoperative complications included non-union at the allograft/host junction (which united after auto grafting) and superficial wound infections that resolved after antibiotic therapy. All surgical procedures were performed by a team headed by an orthopedic oncologist and shoulder surgeon. At latest follow-up (December 2001) all patients, with the exception of one (who was at stage 3-B at presentation) were alive, and had good function of the upper limb. It is our opinion that the team approach comprising an orthopedic oncologist and shoulder surgeon greatly contributed to the good surgical outcome, and hence the good survival and functional results of the patients. Bone allograft offers a modular malleable durable solution to the resected bone segment.

Antero-posterior activity changes in the superficial masseter muscle after exposure to experimental pain

The aim of this randomized, controlled, double-blind study was to examine how the activation pattern of the masseter muscle changes during natural function when experimental pain is induced in a discrete anterior area of the muscle. In 20 subjects, three bipolar surface electrodes and three intramuscular fine-wire electrodes (antero-posterior mapping) were simultaneously attached above and in the right masseter muscle to record the electromyographic (EMG) activity during unilateral chewing before and after infusion of a 0.9% isotonic and 5% hypertonic saline bolus in the anterior area of the muscle. The activity of the contralateral masseter muscle was registered by surface electrodes. In addition, the development of pain intensity was quantitatively measured with a numerical rating scale (NRS). While both saline concentrations caused pain, the hypertonic solution evoked stronger pain. The experiments also provided evidence of a significant although differential activity reduction of the ipsilateral masseter muscle in the antero-posterior direction. The activity reduction decreased with increasing distance from the location of the infusion. The results support the idea that the strategy of differential activation protects the injured muscle while simultaneously maintaining optimal function.

Frequency and predictors of osteoporotic fractures after cardiac or liver transplantation: a follow-up study

BACKGROUND

Osteoporosis and related fractures are a major complication after organ transplantation. The aim of this study was to find out the frequency and predictors of osteoporotic fractures after cardiac or liver transplantation.

METHODS

235 consecutive patients who had a cardiac transplant (n=105; 88 men, 17 women) or a liver transplant (130; 75 men, 55 women) were followed. Vertebral fractures were assessed by a standardised analysis of spinal radiographs before and annually after transplantation. Clinical and non-vertebral fracture data were noted from hospital records.

FINDINGS

In the first and second years after transplantation, the proportion of patients (Kaplan-Meier estimates) who had at least one vertebral fracture was slightly higher in the cardiac group (first year 21%, second year 27%) than in the liver group (first year 14%, second year 21%). In the third and fourth years, one third of patients from both groups had had one or more vertebral fractures. Non-vertebral fractures occurred in nine patients (7%) after liver transplantation and avascular necrosis of the hip head in three patients (3%) after cardiac transplantation. In both groups, no dose-dependent effect of immunosuppressive therapy on fracture development could be identified. Independent predictors assessed by multivariate analysis were age (hazard ratio [95% CI] increase of 5 years, 1.71 [1.1-2.7]) and lumbar bone-mineral density (decrease of 1 SD t score, 1.97 [1.2-3.2]) in cardiac transplantation patients, and vertebral fractures before transplantation (6.07 [1.7-21.7]) in the liver group.

INTERPRETATION

The high frequency of osteoporotic fractures in the 2 years after transplantation and the limitations of reliable fracture-risk predictions, show the need to investigate preventive therapies.