Elevated serum concentrations of cobalt, chromium, nickel, and manganese after metal-on-metal alloarthroplasty of the hip: a prospective randomized study

In this prospective randomized study, we investigate metal ion concentrations and clinical outcome 2 years after metal-on-metal (28 patients) or metal-on-polyethylene (26 patients) hip arthroplasty with 28-mm modular heads. Metal ion concentrations in patient serum were analyzed by high-resolution plasma mass spectrometry. The clinical outcome was almost identical in both groups with respect to the Harris hip score and the Medical Outcome Study Short Form-36; and on plain radiography, no signs of loosening occurred in any group. In the metal-on-metal group, concentrations of all investigated ions increased significantly when compared with preoperative values: cobalt, 15.3-fold (95% confidence interval [CI], 9.4-21.2); chromium, 5.2-fold (CI, 3.5-7.0); nickel, 2.1-fold (CI, 1.2-3.0); and manganese, 1.6-fold (CI, 1.3-2.0). In the metal-on-polyethylene group, a smaller but significant increase in the concentrations of cobalt and nickel occurred, whereas concentrations of the other ions did not change significantly.

A new CT method for measuring cup orientation after total hip arthroplastyA study of 10 patients

BACKGROUND

It is difficult to assess the orientation of the acetabular component on routine radiographs. We present a method for determining the spatial orientation of the acetabular component after total hip arthroplasty (THA) using computed tomography.

PATIENTS AND METHODS

Two CT-scans, 10 min apart, were obtained from each of 10 patients after THA. Using locally developed software, two independent examiners measured the orientation of the acetabular component in relation to the pelvis. The measurements were repeated after one week. To be independent of the patient position during scanning, the method involved two steps. Firstly, a 3D volumetric image of the pelvis was brought into a standard pelvic orientation, then the orientation of the acetabular component was measured. The orientation of the acetabular component was expressed as operative anteversion and inclination relative to an internal pelvic reference coordinate system. To evaluate precision, we compared measurements across pairs of CT volumes between observers and trials.

RESULTS

Mean absolute interobserver angle error was 2.3 degrees for anteversion (range 0-6.6 degrees), and 1.1 degrees for inclination (range 0-4.6 degrees). For interobserver measurements, the precision, defined as one standard deviation, was 2.9 degrees for anteversion, and 1.5 degrees for inclination. A Student's t-test showed that the overall differences between the examiners, trials, and cases were not significant. Data were normally distributed and were not dependent on examiner or trial.

INTERPRETATION

We conclude that the implant angles of the acetabular component in relation to the pelvis could be detected repeatedly using CT, independently of patient positioning.

Distal femoral stem-bone anchorage of a cementless revision total hip arthroplasty: evaluation of 14 patients by CT

BACKGROUND AND PURPOSE

According to the manual of the cementless Link MP reconstruction prosthesis, a distal femoral stem-bone anchorage of at least 80 mm is necessary to gain implant stability. There have been no in vivo studies showing that this distance is either achieved in clinical practice or needed for clinically satisfying results. Thus, we assessed the femoral stem-bone anchorage of the MP prosthesis using CT.

METHODS

14 patients with the MP stem were evaluated by CT scans at a median follow-up time of 12 months postoperatively. Femoral stem-bone anchorage was defined as adequate if 50% of the stem flutes or more had cortical bone contact. The length of anchorage was derived from the number of slices with adequate anchorage. Clinical outcome was assessed with VAS for pain and Harris hip score (HHS), both at 1 and 5 years of follow-up.

RESULTS

The median length of stem-bone anchorage was 33 mm (interquartile range 10-60), which was shorter than recommended (p = 0.002). Still, at the 1-year control, all patients were fully weight-bearing and only 1/14 complained about mild thigh pain. 7/14 patients did not experience any pain in the affected hip. The patients had a median of 85 points in the HHS. The clinical outcome at 5 years was unchanged.

INTERPRETATION

We found that it can be difficult to achieve a stem-bone anchorage of at least 80 mm for the MP Link prosthesis. However, this does not appear to be necessary to obtain stability and to achieve clinically satisfying results.

The disintegrin-metalloproteinases ADAM 10, 12 and 17 are upregulated in invading peripheral tumor cells of basal cell carcinomas

BACKGROUND

Members of the a disintegrin and metalloproteinase (ADAM) family are expressed in malignant tumors and participate in the pathogenesis of cancer. However, the presence of ADAM 10, 12, 17 and their role in basal cell carcinoma (BCC) have not been described. The purpose of this study was to investigate expression of ADAM 10, 12 and 17 in BCC.

METHODS

Expression of ADAM 10, 12 and 17 was analyzed by immunohistochemistry in skin tissues obtained from 25 patients with different types of BCC.

RESULTS

Immunoreactivity of ADAM 10, 12 and 17 was increased at the peripheral tumor margin compared with central areas of BCC tumor cell nests. Immunoreactivity of ADAM 10 and 12 was increased in the deep margin of invading tumor cell nests in mixed BCC. Focally increased expression of ADAM 12 was detected in squamous differentiated tumor cells of nodular BCC. In addition, immunoreactivity of ADAM 17 was increased in superficial BCC.

CONCLUSIONS

ADAM 10, 12 and 17 showed different expression pattern in BCC histologic subtypes, indicating their different role in the BCC pathogenesis. Overexpression of ADAM 10, 12 and 17 immunoreactivity in deep invasion area of BCC indicates that these three proteases may play an important role in the locally invasive and highly destructive growth behavior of BCC. Additionally, we suggest that ADAM 17 may play an important role in early development of BCC.

Intracranial trigeminal nerve metastasis of a desmoplastic neurotropic melanoma: case report

BACKGROUND

Desmoplastic neurotropic mela-noma is a rare and highly malignant variant of melanoma. Solitary nervus trigeminus and Gasserian ganglion metastasis of a neurotropic melanoma has not been previously described in the literature.

CASE DESCRIPTION

A 69-year-old man presented to our clinic with trigeminal neuralgia. 4 years previously he underwent tumor removal with an initial diagnosis of amelanotic malignant cutaneous melanoma; 1 year later, because of tumor recurrence, the patient underwent neck dissection, chemotherapy and radiation. Magnet resonance imaging (MRI) disclosed an enhancement of the Gasserian ganglion and tumor extension along the mandibular and maxillar nerves of the intracranial part of the trigeminal nerve suggestive of tumor. The intraoperative macroscopic appearance of the tumor was compatible with a neurinoma. Histopathological studies proved the tumor to be a desmoplastic neurotropic melanoma (DNM) that was related to the previously treated malignant melanoma.

CONCLUSION

A metastatic tumor arising solely in a trigeminal nerve from a cutaneous malignant melanoma is quite rare; to our knowledge this may be the first report of such a case in the literature.

Gait pattern in rheumatoid arthritis

The purpose of this study was to analyse kinematic and kinetic gait changes in rheumatoid arthritis (RA) patients in comparison to healthy controls and to examine whether levels of functional disability (Health Assessment Questionnaire (HAQ)-scores) were associated with gait parameters. Using a three-dimensional motion analysis system, kinematic and kinetic gait parameters were measured in 50 RA patients and 37 healthy controls. There was a significant reduction in joint motions, joint moments and work in the RA cohort compared with healthy controls. The following joint motions were decreased: hip flexion-extension range (Delta6 degrees ), hip abduction (Delta4 degrees ), knee flexion-extension range (Delta8 degrees ) and ankle plantarflexion (Delta10 degrees ). The following joint moments were reduced: hip extensor (Delta0.30Nm/kg) and flexor (Delta0.20Nm/kg), knee extensor (Delta0.11Nm/kg) and flexor (Delta0.13Nm/kg), and ankle plantarflexor (Delta0.44Nm/kg). Work was lower in hip positive work (Delta0.07J/kg), knee negative work (Delta0.08J/kg) and ankle positive work (Delta0.15J/kg). Correlations were fair although significant between HAQ and hip flexion-extension range, hip abduction, knee flexion-extension range, hip abductor moment, stride length, step length and single support (r=-0.30 to -0.38, p<0.05). Our findings suggest that RA patients have overall less joint movement and specifically restricted joint moments and work across the large joints of the lower limbs during walking than healthy controls. There were only fair associations between levels of functional disability and gait parameters. The findings of this study help to improve the understanding how RA affects gait changes in the lower limbs.

Decreasing incidence of tibial shaft fractures between 1998 and 2004: information based on 10,627 Swedish inpatients

BACKGROUND AND PURPOSE

There is a lack of national epidemiological data on the characteristics of patients with tibial shaft fractures. We therefore analyzed data on Swedish patients with tibial shaft fractures in this nationwide population study based on data from 1998 through 2004.

METHODS

Data on all patients with tibial shaft fractures were extracted from the Swedish National Hospital Discharge Register.

RESULTS

We identified 10,627 hospital admissions for tibial shaft fractures, corresponding to an annual incidence rate of 17 per 100,000 person-years (pyr). The number of hospital admissions decreased by 12% during the period 1998-2004, mostly from a reduction in male incidence. The median (SD) age at admission was 28 (22) years for men and 51 (26) years for women. The two major mechanisms of injury were falls on the same level (48%) and transport accidents (21%). Surgical procedures were dominated by osteosynthesis with nail (48%), followed by closed reduction and plaster cast (27%), and external fixation (12%). 12% of all tibial shaft fractures were classified as open, corresponding to an incidence rate of 2.3 per 100,000 pyr, which declined during 1998-2004.

INTERPRETATION

This nationwide study of tibial shaft fractures shows a falling off of fracture incidence, a finding that can be used to advantage by healthcare providers.

Variation in the position of the elbow flexion axis after total joint replacement with three different prostheses

The instantaneous flexion axes in rheumatoid patients treated with a Kudo (Biomet UK Ltd, Swindon, UK), Capitellocondylar (Johnson & Johnson Orthopaedics Inc, Raynham, MA), or GSB III (Zimmer GmbH, Winterthur, Switzerland) elbow prosthesis were calculated using radiostereometric analysis and compared with those previously found in the normal elbow in vivo. Variability in the flexion axis position was greater in the prosthetic elbows than reported for healthy subjects. This was especially evident for the unlinked Kudo prosthesis, with dispersions of the axes up to 84.3 degrees in the frontal and 45.0 degrees in the horizontal plane. Corresponding values for the unlinked Capitellocondylar prosthesis were 19.7 degrees and 20.9 degrees. The linked GSB III prosthesis was the most constrained, with dispersions within 15.4 degrees in the frontal and 4.6 degrees in the horizontal plane. The unlinked elbow prostheses displayed considerable axis dispersion under physiologic conditions. Implant design seems to be able to compensate for this to some extent, as indicated, for example, by the results of the Capitellocondylar prosthesis.

Decrease of RA-related orthopaedic surgery of the upper limbs between 1998 and 2004: data from 54,579 Swedish RA inpatients

OBJECTIVES

To describe the overall use and temporal trends in orthopaedic upper limb surgery associated with RA on a nation wide basis in Sweden between 1998 and 2004.

METHODS

Data for all inpatient visits during 1998-2004 for patients older than 18 yrs with RA-related diagnoses were extracted from the Swedish National Hospital Discharge Registry (SNHDR). The SNHDR prospectively collects data on all hospital admissions in Sweden according to the International Classification of Diseases (ICD). Data were analysed with respect to orthopaedic surgery of the hand, elbow and shoulder.

RESULTS

During the study period, 54,579 individual RA patients were admitted to a Swedish hospital and 9% of these underwent RA-related surgery of the upper limbs. The RA patient cohort underwent a total of 8251 RA-related upper limb surgical procedures. The hand (77%) was most frequently operated on, followed by the shoulder (13%) and the elbow (10%). There was a statistically significant decrease of 31% for all admissions associated with RA-related upper limb surgery during 1998-2004 (P = 0.001). Some 10% of all RA-related upper limb surgery was due to total joint arthroplasties (TJAs), mostly for the elbow (59%). During 1998-2004, all TJAs, elbow-TJAs and shoulder-TJAs had a stable occurrence. In contrast, the overall numbers of hand-TJAs significantly increased (P = 0.009).

CONCLUSIONS

Rates of RA-related upper limb surgery decreased and TJAs had a stable occurrence in Sweden during 1998-2004. The findings of this study may reflect trends in disease management and health outcomes of RA patients in Sweden.

Frequency, determinants, and temporal trends in lymph node assessment in women with ductal carcinoma in situ

11050

Background: This study examined factors associated with lymph node (LN) assessment in women with ductal carcinoma in situ (DCIS) at two sites in the U.S. Methods: Detailed clinical, pathologic, and radiographic information was collected through medical record review for 1090 patients with pure DCIS treated between 1985 and 2000 in Monroe County, New York and the Henry Ford Health System (HFHS), Detroit, Michigan. Sociodemographic, clinical, pathologic, and radiologic factors associated with LN assessment were examined using logistic regression models. Covariates were interacted with a site indicator; models were tested down to include only interactions with treatment and year. Results: 395 (36.2%) women had LN assessment; 43 of these were sentinel node dissections. Of the 438 women who had a mastectomy, 341 (86.3%) had LN assessment compared with 54 (13.7%) of the 598 women who had breast conserving surgery (p = 0.0001). In multivariate logistic regression, factors positively associated with LN assessment were mastectomy (OR, 45.5 95% CI 23.9, 86.5), private insurance (OR 2.3, 95% CI 1.2, 4.4), and high nuclear grade (OR 3.7, 95% CI 1.5, 9.2). Smoking was negatively associated with LN assessment (OR 0.5, 95% CI .3, .9). Age, race, method of detection (palpable mass vs. mammography), histologic subtype, and presence of multifocal disease were not associated with LN assessment. Statistically significant downward trends over time existed and did not differ between the two sites. LN assessment rates differed by treatment by site. Women who had mastectomy at HFHS were more likely to have LN assessment than women who had mastectomy in Monroe County (OR 5.0, 95% CI 1.5, 16.7), but women at HFHS who had autogenous reconstruction following mastectomy were substantially less likely to have LN assessment than their counterparts in Monroe County (OR 0.2, 95% CI .04, .65). Conclusions: The finding that LN assessment rates in women with DCIS vary according to non-clinical factors, such as treatment site and insurance type, suggests uncertainty about the role of LN assessment exists. Local treatment culture and financial incentives may play a role in the variations in LN assessment patterns.

No significant financial relationships to disclose.

Ankle/hindfoot arthrodesis in rheumatoid arthritis improves kinematics and kinetics of the knee and hip: a prospective gait analysis study

OBJECTIVES

To evaluate the effects of ankle/hindfoot arthrodesis in rheumatoid arthritis (RA) patients on gait pattern of the knee and hip.

METHODS

In this prospective follow-up study, 14 RA patients scheduled for ankle/hindfoot arthrodesis (talo-calcaneal, talo-navicular, calcaneo-cuboid and/or talo-crural joints) and 14 age- and sex-matched healthy controls were included. Three-dimensional gait analyses of joint angles, moments and work were performed at the index operation and after 13 months of follow-up. Each patient underwent clinical assessments of pain while walking, overall evaluation of disease activity, Health Related Quality of Life Questionnaire (EQ-5D), activity limitations, maximum walking distance, difficulty with walking surface and gait abnormality. For comparisons of pre- vs post-operative conditions, Wilcoxon's matched pairs test and Friedman ANOVA by rank test were used.

RESULTS

At follow-up after ankle/hindfoot fusion surgery, RA patients demonstrated a statistically significant improvement in mean range of joint motions, moments and work in the overlying joints such as the knee and hip. Moreover, there was significantly less pain, disease activity, activity limitation, difficulty with walking surface and gait abnormality. EQ-5D and maximum walking distance were also significantly improved at follow-up.

CONCLUSIONS

Our results demonstrate that ankle/hindfoot arthrodesis in RA is an effective intervention to reduce pain and to improve Health Related Quality of Life and functional ability. Moreover, the overlying leg joints experience an improvement in joint motion, muscle-generated joint moments and work during walking. Three-dimensional gait analysis may assist future investigations of the effects of orthopaedic surgery on functional mobility in RA to prevent irreversible disablement.

Effects on osteoclast and osteoblast activities in cultured mouse calvarial bones by synovial fluids from patients with a loose joint prosthesis and from osteoarthritis patients

Aseptic loosening of a joint prosthesis is associated with remodelling of bone tissue in the vicinity of the prosthesis. In the present study, we investigated the effects of synovial fluid (SF) from patients with a loose prosthetic component and periprosthetic osteolysis on osteoclast and osteoblast activities in vitro and made comparisons with the effects of SF from patients with osteoarthritis (OA). Bone resorption was assessed by the release of calcium 45 (⁴⁵Ca) from cultured calvariae. The mRNA expression in calvarial bones of molecules known to be involved in osteoclast and osteoblast differentiation was assessed using semi-quantitative reverse transcription-polymerase chain reaction (PCR) and real-time PCR. SFs from patients with a loose joint prosthesis and patients with OA, but not SFs from healthy subjects, significantly enhanced ⁴⁵Ca release, effects associated with increased mRNA expression of calcitonin receptor and tartrate-resistant acid phosphatase. The mRNA expression of receptor activator of nuclear factor-kappa-B ligand (rankl) and osteoprotegerin (opg) was enhanced by SFs from both patient categories. The mRNA expressions of nfat2 (nuclear factor of activated T cells 2) and oscar (osteoclast-associated receptor) were enhanced only by SFs from patients with OA, whereas the mRNA expressions of dap12 (DNAX-activating protein 12) and fcrγ (Fc receptor common gamma subunit) were not affected by either of the two SF types. Bone resorption induced by SFs was inhibited by addition of OPG. Antibodies neutralising interleukin (IL)-1α, IL-1β, soluble IL-6 receptor, IL-17, or tumour necrosis factor-α, when added to individual SFs, only occasionally decreased the bone-resorbing activity. The mRNA expression of alkaline phosphatase and osteocalcin was increased by SFs from patients with OA, whereas only osteocalcin mRNA was increased by SFs from patients with a loose prosthesis. Our findings demonstrate the presence of a factor (or factors) stimulating both osteoclast and osteoblast activities in SFs from patients with a loose joint prosthesis and periprosthetic osteolysis as well as in SFs from patients with OA. SF-induced bone resorption was dependent on activation of the RANKL/RANK/OPG pathway. The bone-resorbing activity could not be attributed solely to any of the known pro-inflammatory cytokines, well known to stimulate bone resorption, or to RANKL or prostaglandin E₂ in SFs. The data indicate that SFs from patients with a loose prosthesis or with OA stimulate bone resorption and that SFs from patients with OA are more prone to enhance bone formation.

The effect of a low-carbohydrate diet on the nonalcoholic fatty liver in morbidly obese patients before bariatric surgery

BACKGROUND

Bariatric surgery may be complicated by enlargement of the liver, especially of the left lobe, caused by nonalcoholic fatty liver disease often present with morbid obesity.

METHODS

The effect of a very low carbohydrate diet for 4 weeks before surgery on liver density and volume was assessed in 14 candidates for bariatric surgery. Computed tomography (CT) scans were performed before and at termination of the diet period.

RESULTS

The CT scans clearly showed a significant increase in mean liver density (p = 0.06) and a decrease in mean liver volume (p = 0.01). The increased mean density of the left lobe was markedly greater than that of the right lobe.

CONCLUSIONS

The findings show that 4 weeks of a very low carbohydrate diet reduces liver fat content and liver size, particularly of the left lobe. This approach may render bariatric surgery or any foregut operations less difficult in morbidly obese patients and may be a useful treatment for nonalcoholic fatty liver disease.

Albumin-bound lipids induce free cytoplasmic calcium oscillations in human osteoblast-like cells

[Ca(2+)](i) oscillations were found in human osteoblast-like cells (hOB cells) exposed to high-lipid bovine serum albumin (BSA), but not when exposed to low-lipid BSA. These [Ca(2+)](i) oscillations were inhibited by heptanol and suramin, which implies that gap junctions and purinergic signalling may be important for these [Ca(2+)](i) oscillations. The high-lipid BSA preparation that was used contains arachidonic acid. [Ca(2+)](i) oscillations could be induced by low lipid albumin with arachidonic acid added. The albumin-bound lipids were also important for osteoblast growth since DNA synthesis and the total cell protein content was higher in hOB cells exposed to high-lipid BSA. The effect of arachidonic acid on hOB cell proliferation was bone-donor dependent; both stimulatory and inhibitory effects were observed. The physiological importance of albumin-bound lipids is unclear; given that albumin has only minimal contact with osteoblasts under normal conditions. Only when bone capillaries are disrupted, e.g. during a fracture, would significant amounts of albumin reach osteoblasts. Albumin-bound lipids could therefore contribute to stimulation of osteoblast proliferation during fracture healing.

Arthrodesis versus Mayo resection

In a prospective randomised study 31 patients were allocated to either arthrodesis or Mayo resection of the first metatarsophalangeal joint as part of a total reconstruction of the rheumatoid forefoot. Of these, 29 were re-examined after a mean of 72 months (57 to 80), the Foot Function Index was scored and any deformity measured. Load distribution was analysed using a Fscan mat in 14 cases, and time and distance were measured in 12 of these patients using a 3D Motion system. We found excellent patient satisfaction and a significant, lasting reduction of the Foot Function Index, with no statistically significant differences between the groups. There were no significant differences in recurrence of the deformity, the need for special shoes, gait velocity, step length, plantar moment, mean pressure or the position of the centre of force under the forefoot. The cadence was higher and the stance phase shorter in the fusion group.

These results suggest that a Mayo resection may be an equally good option for managing the first metatarsophalangeal joint in reconstruction of the rheumatoid forefoot.